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Institute
- Klinik und Poliklinik für Allgemein-, Viszeral-, Gefäß- und Kinderchirurgie (Chirurgische Klinik I) (229) (remove)
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Melanoma and Merkel cell carcinoma (MCC) are highly aggressive cancers of the skin that frequently escape immune recognition and acquire resistance to chemotherapeutic agents, which poses a major obstacle to successful cancer treatment. Recently, a new class of therapeutics targeting the programmed cell death-1 (PD-1) immune checkpoint receptor has shown remarkable efficacy in the treatment of both cancers. Blockade of PD-1 on T cells activates cancer-specific immune responses that can mediate tumor regression. The data presented in this Ph.D. thesis demonstrates that PD-1 is also expressed by subsets of cancer cells in melanoma and MCC. Moreover, this work identifies PD-1 as a novel tumor cell-intrinsic growth receptor, even in the absence of T cell immunity. PD-1 is expressed by tumorigenic cell subsets in melanoma patient samples and established human and murine cell lines that also co-express ABCB5, a marker of immunoregulatory tumor- initiating cells in melanoma. Consistently, melanoma-expressed PD-1 downmodulates T effector cell functions and increases the intratumoral frequency of tolerogenic myeloid- derived suppressor cells. PD-1 inhibition on melanoma cells by RNA interference, blocking antibodies, or mutagenesis of melanoma-PD-1 signaling motifs suppresses tumor growth in immunocompetent, immunocompromised, and PD-1-deficient tumor graft recipient mice. Conversely, melanoma-specific PD-1 overexpression enhances tumorigenicity, including in mice lacking adaptive immunity. Engagement of melanoma- PD-1 by its ligand PD-L1 promotes tumor growth, whereas melanoma-PD-L1 inhibition or knockout of host-PD-L1 attenuates growth of PD-1-positive melanomas. Mechanistically, the melanoma-PD-1 receptor activates mTOR signaling mediators, including ribosomal protein S6. In a proof-of-concept study, tumoral expression of phospho-S6 in pretreatment tumor biopsies correlated with clinical responses to anti-PD-1 therapy in melanoma patients. In MCC, PD-1 is similarly co-expressed by ABCB5+ cancer cell subsets in clinical tumor specimens and established human cell lines. ABCB5 renders MCC cells resistant to the standard-of-care chemotherapeutic agents, carboplatin and etoposide. Antibody-mediated ABCB5 blockade reverses chemotherapy resistance and inhibits tumor xenograft growth by enhancing chemotherapy-induced tumor cell killing. Furthermore, engagement of MCC-expressed PD-1 by its ligands, PD-L1 and PD-L2, promotes proliferation and activates MCC-intrinsic mTOR signaling. Consistently, antibody- mediated PD-1 blockade inhibits MCC tumor xenograft growth and phosphorylation of mTOR effectors in immunocompromised mice. In summary, these findings identify cancer cell-intrinsic functions of the PD-1 pathway in tumorigenesis and suggest that blocking melanoma- and MCC-expressed PD-1 might contribute to the striking clinical efficacy of anti-PD-1 therapy. Additionally, these results establish ABCB5 as a previously unrecognized chemoresistance mechanism in MCC.
Background:
Vascular damage in polytrauma patients is associated with high mortality and morbidity. Therefore, specific clinical implications of vascular damage with fractures in major trauma patients are reassessed.
Methods:
This comprehensive nine-year retrospective single center cohort study analyzed demography, laboratory, treatment and outcome data from 3689 patients, 64 patients with fracture-associated vascular injuries were identified and were compared to a control group.
Results:
Vascular damage occurred in 7% of patients with upper and lower limb and pelvic fractures admitted to the trauma room. Overall survival was 80% in pelvic fracture and 97% in extremity fracture patients and comparable to non-vascular trauma patients. Additional arterial damage required substantial fluid administration and was visible as significantly anemia and disturbed coagulation tests upon admission. Open procedures were done in over 80% of peripheral extremity vascular damage. Endovascular procedures were predominant (87%) in pelvic injury.
Conclusion:
Vascular damage is associated with high mortality rates especially in combination with pelvic fractures. Initial anemia, disturbed coagulation tests and the need for extensive pre-clinical fluid substitution were observed in the cohort with vascular damage. Therefore, fast diagnosis and early interventional and surgical procedures are necessary to optimize patient-specific outcome.
Background:
Ketogenic diets (KDs) or short-term fasting are popular trends amongst supportive approaches for cancer patients. Beta-hydroxybutyrate (3-OHB) is the main physiological ketone body, whose concentration can reach plasma levels of 2–6 mM during KDs or fasting. The impact of 3-OHB on the biology of tumor cells described so far is contradictory. Therefore, we investigated the effect of a physiological concentration of 3 mM 3-OHB on metabolism, proliferation, and viability of breast cancer (BC) cells in vitro.
Methods:
Seven different human BC cell lines (BT20, BT474, HBL100, MCF-7, MDA-MB 231, MDA-MB 468, and T47D) were cultured in medium with 5 mM glucose in the presence of 3 mM 3-OHB at mild hypoxia (5% oxygen) or normoxia (21% oxygen). Metabolic profiling was performed by quantification of the turnover of glucose, lactate, and 3-OHB and by Seahorse metabolic flux analysis. Expression of key enzymes of ketolysis as well as the main monocarboxylic acid transporter MCT2 and the glucose-transporter GLUT1 was analyzed by RT-qPCR and Western blotting. The effect of 3-OHB on short- and long-term cell proliferation as well as chemo- and radiosensitivity were also analyzed.
Results:
3-OHB significantly changed the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) in BT20 cells resulting in a more oxidative energetic phenotype. MCF-7 and MDA-MB 468 cells had increased ECAR only in response to 3-OHB, while the other three cell types remained uninfluenced. All cells expressed MCT2 and GLUT1, thus being able to uptake the metabolites. The consumption of 3-OHB was not strongly linked to mRNA overexpression of key enzymes of ketolysis and did not correlate with lactate production and glucose consumption. Neither 3-OHB nor acetoacetate did interfere with proliferation. Further, 3-OHB incubation did not modify the response of the tested BC cell lines to chemotherapy or radiation.
Conclusions:
We found that a physiological level of 3-OHB can change the energetic profile of some BC cell lines. However, 3-OHB failed to influence different biologic processes in these cells, e.g., cell proliferation and the response to common breast cancer chemotherapy and radiotherapy. Thus, we have no evidence that 3-OHB generally influences the biology of breast cancer cells in vitro.
In tissue engineering, the generation and functional maintenance of dense voluminous tissues is mainly restricted due to insufficient nutrient supply. Larger three-dimensional constructs, which exceed the nutrient diffusion limit become necrotic and/or apoptotic in long-term culture if not provided with an appropriate vascularization. Here, we established protocols for the generation of a pre-vascularized biological scaffold with intact arterio-venous capillary loops from rat intestine, which is decellularized under preservation of the feeding and draining vascular tree. Vessel integrity was proven by marker expression, media/blood reflow and endothelial LDL uptake. In vitro maintenance persisted up to 7 weeks in a bioreactor system allowing a stepwise reconstruction of fully vascularized human tissues and successful in vivo implantation for up to 4 weeks, although with time-dependent decrease of cell viability. The vascularization of the construct lead to a 1.5× increase in cellular drug release compared to a conventional static culture in vitro. For the first time, we performed proof-of-concept studies demonstrating that 3D tissues can be maintained within a miniaturized vascularized scaffold in vitro and successfully implanted after re-anastomosis to the intrinsic blood circulation in vivo. We hypothesize that this technology could serve as a powerful platform technology in tissue engineering and regenerative medicine.
The number of bariatric surgeries being performed worldwide has markedly risen. While the improvement in obesity-associated comorbidities after bariatric surgery is well-established, very little is known about its impact on cancer risk. The peripheral lymphocyte micronucleus test is a widely used method for the monitoring of chromosomal damage levels in vivo, and micronucleus frequency positively correlates with cancer risk. Therefore, the aim of this study was to compare the micronucleus frequency before and after bariatric surgery in obese subjects. Peripheral blood mononuclear cells were collected from 45 obese subjects before and at two time-points after bariatric surgery (6 and 12 months) to assess spontaneous micronucleus frequency. Consistent with the increased cancer risk previously shown, bariatric surgery-induced weight loss led to a significant reduction in lymphocyte micronucleus frequency after 12 months. Interestingly, comorbidities such as type 2 diabetes mellitus and metabolic syndrome further seemed to have an impact on the lymphocyte micronucleus frequency. Our findings may indicate a successful reduction of cancer risk in patients following weight loss caused by bariatric surgery.
Background:
The treatment strategies for colorectal cancer located in the right side of the colon have changed dramatically during the last decade. Due to the introduction of complete mesocolic excision (CME) with central ligation of the vessels and systematic lymph node dissection, the long-term survival of affected patients has increased significantly. It has also been proposed that right-sided colon resection can be performed laparoscopically with the same extent of resection and equal long-term results.
Methods:
A retrospective evaluation of a prospectively expanded database on right-sided colorectal cancer or adenoma treated at the University Hospital of Wuerzburg between 2009 and 2016 was performed. All patients underwent CME. This data was analyzed alone and in comparison to the published data describing laparoscopic right-sided colon resection for colon cancer.
Results:
The database contains 279 patients, who underwent right-sided colon resection due to colorectal cancer or colorectal adenoma (255 open; 24 laparoscopic). Operation data (time, length of stay, time on ICU) was equal or superior to laparoscopy, which is comparable to the published results. Surprisingly, the surrogate parameter for correct CME (the number of removed lymph nodes) was significantly higher in the open group. In a subgroup analysis only including patients who were feasible for laparoscopic resection and had been operated with an open procedure by an experienced surgeon, operation time was significantly shorter and the number of removed lymph nodes is significantly higher in the open group.
Conclusion:
So far, several studies demonstrate that laparoscopic right-sided colon resection is comparable to open resection. Our data suggests that a consequent CME during an open operation leads to significantly more removed lymph nodes than in laparoscopically resected patients and in several so far published data of open control groups from Europe. Further prospective randomized trials comparing the long-term outcome are urgently needed before laparoscopy for right-sided colon resection can be recommended ubiquitously.
TNF-like weak inducer of apoptosis (TWEAK) and inhibition of protein synthesis with cycloheximide (CHX) sensitize for poly(I:C)-induced cell death. Notably, although CHX preferentially enhanced poly(I:C)-induced apoptosis, TWEAK enhanced primarily poly(I:C)-induced necroptosis. Both sensitizers of poly(I:C)-induced cell death, however, showed no major effect on proinflammatory poly(I:C) signaling. Analysis of a panel of HeLa-RIPK3 variants lacking TRADD, RIPK1, FADD, or caspase-8 expression revealed furthermore similarities and differences in the way how poly(I:C)/TWEAK, TNF, and TRAIL utilize these molecules for signaling. RIPK1 turned out to be essential for poly(I:C)/TWEAK-induced caspase-8-mediated apoptosis but was dispensable for this response in TNF and TRAIL signaling. TRADD-RIPK1-double deficiency differentially affected poly(I:C)-triggered gene induction but abrogated gene induction by TNF completely. FADD deficiency abrogated TRAIL- but not TNF- and poly(I:C)-induced necroptosis, whereas TRADD elicited protective activity against all three death inducers. A general protective activity against poly(I:C)-, TRAIL-, and TNF-induced cell death was also observed in FLIPL and FLIPS transfectrants.
Background:
The use of venoarterial extracorporeal membrane oxygenation (va-ECMO) via peripheral cannulation for septic shock is limited by blood flow and increased afterload for the left ventricle.
Case Report:
A 15-year-old girl with acute myelogenous leukemia, suffering from severe septic and cardiogenic shock, was treated by venoarterial extracorporeal membrane oxygenation (va-ECMO). Sufficient extracorporeal blood flow matching the required oxygen demand could only be achieved by peripheral cannulation of both femoral arteries. Venous drainage was performed with a bicaval cannula inserted via the left V. femoralis. To accomplish left ventricular unloading, an additional drainage cannula was placed in the left atrium via percutaneous atrioseptostomy (va-va-ECMO). Cardiac function recovered and the girl was weaned from the ECMO on day 6. Successful allogenic stem cell transplantation took place 2 months later.
Conclusions:
In patients with vasoplegic septic shock and impaired cardiac contractility, double peripheral venoarterial extracorporeal membrane oxygenation (va-va-ECMO) with transseptal left atrial venting can by a lifesaving option.
Background:
Metastatic Adrenocortical Carcinoma (ACC) is a rare malignancy with a poor 5-year-survival rate (<15%). A surgical approach is recommended in selected patients if complete resection of distant metastasis can be achieved. To date there are only limited data on the outcome after surgical resection of hepatic metastases of ACC.
Methods:
A retrospective analysis of the German Adrenocortical Carcinoma Registry was conducted. Patients with liver metastases of ACC but without extrahepatic metastases or incomplete tumour resection were included.
Results:
Seventy-seven patients fulfilled these criteria. Forty-three patients underwent resection of liver metastases of ACC. Complete tumour resection (R0) could be achieved in 30 (69.8%). Median overall survival after liver resection was 76.1 months in comparison to 10.1 months in the 34 remaining patients with unresected liver metastases (p < 0.001). However, disease free survival after liver resection was only 9.1 months. Neither resection status (R0/R1) nor extent of liver resection were significant predictive factors for overall survival. Patients with a time interval to the first metastasis/recurrence (TTFR) of greater than 12 months or solitary liver metastases showed significantly prolonged survival.
Conclusions:
Liver resection in the case of ACC liver metastases can achieve long term survival with a median overall survival of more than 5 years, but disease free survival is short despite metastasectomy. Time to recurrence and single versus multiple metastases are predictive factors for the outcome.
Introduction:
During damage control surgery for blunt abdominal traumata simultaneous duodenal perforations can be missed making secondary sufficient surgical treatment challenging. Endoluminal vacuum (EndoVAC™) therapy has been shown to be a revolutionary option but has anatomical and technical limits.
Presentation of the case:
A 59-year old man with hemorrhagic shock due to rupture of the mesenteric root after blunt abdominal trauma received damage control treatment. Within a scheduled second-look, perforation of the posterior duodenal wall was identified. Due to local and systemic conditions, further surgical treatment was limited. Decision for endoscopic treatment was made but proved to be difficult due to the distal location. Finally, double-barreled jejunal stoma was created for transstomal EndoVAC™ treatment. Complete leakage healing was achieved and jejunostomy reversal followed subsequently.
Discussion:
During damage control surgery simultaneous bowel injuries can be missed leading to life-threatening complications with limited surgical options. EndoVAC™ treatment is an option for gastrointestinal perforations but has anatomical limitations that can be sufficiently shifted by a transstomal approach for intestinal leakage.
Conclusion:
In trauma related laparotomy complete mobilization of the duodenum is crucial. As ultima ratio, transstomal EndoVAC™ is a safe and feasible option and can be considered for similar cases.
Background
40–50% of patients with colorectal cancer (CRC) will develop liver metastases (CRLM) during the course of the disease. One third of these patients will additionally develop pulmonary metastases.
Methods
137 consecutive patients with CRLM, were analyzed regarding survival data, clinical, histological data and treatment. Results were stratified according to the occurrence of pulmonary metastases and metastases resection.
Results
39% of all patients with liver resection due to CRLM developed additional lung metastases. 44% of these patients underwent subsequent pulmonary resection. Patients undergoing pulmonary metastasectomy showed a significantly better five-year survival compared to patients not qualified for curative resection (5-year survival 71.2% vs. 28.0%; p = 0.001). Interestingly, the 5-year survival of these patients was even superior to all patients with CRLM, who did not develop pulmonary metastases (77.5% vs. 63.5%; p = 0.015). Patients, whose pulmonary metastases were not resected, were more likely to redevelop liver metastases (50.0% vs 78.6%; p = 0.034). However, the rate of distant metastases did not differ between both groups (54.5 vs.53.6; p = 0.945).
Conclusion
The occurrence of colorectal lung metastases after curative liver resection does not impact patient survival if pulmonary metastasectomy is feasible. Those patients clearly benefit from repeated resections of the liver and the lung metastases.
Colorectal carcinoma (CRC) is the most common cancer of the gastrointestinal tract with frequently dysregulated intracellular signaling pathways, including p53 signaling. The mainstay of chemotherapy treatment of CRC is 5-fluorouracil (5FU) and oxaliplatin. The two anticancer drugs mediate their therapeutic effect via DNA damage-triggered signaling. The small molecule reactivating p53 and inducing tumor apoptosis (RITA) is described as an activator of wild-type and reactivator of mutant p53 function, resulting in elevated levels of p53 protein, cell growth arrest, and cell death. Additionally, it has been shown that RITA can induce DNA damage signaling. It is expected that the therapeutic benefits of 5FU and oxaliplatin can be increased by enhancing DNA damage signaling pathways. Therefore, we highlighted the antiproliferative response of RITA alone and in combination with 5FU or oxaliplatin in human CRC cells. A panel of long-term established CRC cell lines (n = 9) including p53 wild-type, p53 mutant, and p53 null and primary patient-derived, low-passage cell lines (n = 5) with different p53 protein status were used for this study. A substantial number of CRC cells with pronounced sensitivity to RITA (IC\(_{50}\)< 3.0 μmol/l) were identified within established (4/9) and primary patient-derived (2/5) CRC cell lines harboring wild-type or mutant p53 protein. Sensitivity to RITA appeared independent of p53 status and was associated with an increase in antiproliferative response to 5FU and oxaliplatin, a transcriptional increase of p53 targets p21 and NOXA, and a decrease in MYC mRNA. The effect of RITA as an inducer of DNA damage was shown by a strong elevation of phosphorylated histone variant H2A.X, which was restricted to RITA-sensitive cells. Our data underline the primary effect of RITA, inducing DNA damage, and demonstrate the differential antiproliferative effect of RITA to CRC cells independent of p53 protein status. We found a substantial number of RITA-sensitive CRC cells within both panels of established CRC cell lines and primary patient-derived CRC cell lines (6/14) that provide a rationale for combining RITA with 5FU or oxaliplatin to enhance the antiproliferative response to both chemotherapeutic agents.
Background:
Inguinal lymph node dissection (LND) is a surgical procedure with a high morbidity rate. Variations in surgical procedure, such as sparing of the saphenous vein, have been proposed to reduce surgical morbidity. While sparing of the saphenous vein has shown promising results in earlier studies, data for this procedure in melanoma patients are rare. In this retrospective study, we report 10-year findings on the effects of saphenous vein-sparing LND on surgical morbidity and oncologic outcomes in melanoma patients.
Methods:
A retrospective analysis of melanoma patients receiving inguinal LND in our facility between 2003 and 2013 was performed. Patients were divided into two groups: the saphenous vein resection group and the vein sparing group. Surgical morbidity, including wound infection, lymphatic fistula, severe bleeding, neurological complications, and chronic lymphedema, as well as regional recurrence-free survival were investigated.
Results:
A total of 106 patients were included in this study; of these, the saphenous vein was spared in 41 patients (38.7%). The rate of lymphatic fistula was 51.6 vs. 48.8%, wound infection occurred in 31.3 vs. 24.4%, and patients suffered from chronic lymphedema in 30.0 vs. 26.5% in V. saphena magna resection vs. sparing group. Differences observed, however, were not significant. No difference in regional recurrence-free survival between the two study groups was detected.
Conclusions:
The results of our retrospective analysis could not confirm the promising results reported in earlier studies. Thus, sparing of the saphenous vein appears to be optional.
Brain μ-opioid receptors (MORs) stimulate high-fat (HF) feeding and have been implicated in the distinct long term outcomes on body weight of bariatric surgery and dieting. Whether alterations in fat appetite specifically following these disparate weight loss interventions relate to changes in brain MOR signaling is unknown. To address this issue, diet-induced obese male rats underwent either Roux-en-Y gastric bypass (RYGB) or sham surgeries. Postoperatively, animals were placed on a two-choice diet consisting of low-fat (LF) and HF food and sham-operated rats were further split into ad libitum fed (Sham-LF/HF) and body weight-matched (Sham-BWM) to RYGB groups. An additional set of sham-operated rats always only on a LF diet (Sham-LF) served as lean controls, making four experimental groups in total. Corresponding to a stage of weight loss maintenance for RYGB rats, two-bottle fat preference tests in conjunction with small-animal positron emission tomography (PET) imaging studies with the selective MOR radioligand [\(^{11}\)C]carfentanil were performed. Brains were subsequently collected and MOR protein levels in the hypothalamus, striatum, prefrontal cortex and orbitofrontal cortex were analyzed by Western Blot. We found that only the RYGB group presented with intervention-specific changes: having markedly suppressed intake and preference for high concentration fat emulsions, a widespread reduction in [\(^{11}\)C]carfentanil binding potential (reflecting MOR availability) in various brain regions, and a downregulation of striatal and prefrontal MOR protein levels compared to the remaining groups. These findings suggest that the suppressed fat appetite caused by RYGB surgery is due to reduced brain MOR signaling, which may contribute to sustained weight loss unlike the case for dieting.
Limited comprehension of aneurysm pathology has led to inconclusive results from clinical trials. miRNAs are key regulators of post-translational gene modification and are useful tools in elucidating key features of aneurysm pathogenesis in distinct entities of abdominal and popliteal aneurysms. Here, surgically harvested specimens from 19 abdominal aortic aneurysm (AAA) and 8 popliteal artery aneurysm (PAA) patients were analyzed for miRNA expression and histologically classified regarding extracellular matrix (ECM) remodeling and inflammation. DIANA-based computational target prediction and pathway enrichment analysis verified our results, as well as previous ones. miRNA-362, -19b-1, -194, -769, -21 and -550 were significantly down-regulated in AAA samples depending on degree of inflammation. Similar or inverse regulation was found for miR-769, 19b-1 and miR-550, -21, whereas miR-194 and -362 were unaltered in PAA. In situ hybridization verified higher expression of miR-550 and -21 in PAA compared to AAA and computational analysis for target genes and pathway enrichment affirmed signal transduction, cell-cell-interaction and cell degradation pathways, in line with previous results. Despite the vague role of miRNAs for potential diagnostic and treatment purposes, the number of candidates from tissue signature studies is increasing. Tissue morphology influences subsequent research, yet comparison of distinct entities of aneurysm disease can unravel core pathways.
Background
Fermented wheat germ extract (FWGE) sold under the trade name Avemar exhibits anticancer activity in vitro and in vivo. Its mechanisms of action are divided into antiproliferative and antimetabolic effects. Its influcence on cancer cell metabolism needs further investigation. One objective of this study, therefore, was to further elucidate the antimetabolic action of FWGE. The anticancer compound 2,6-dimethoxy-1,4-benzoquinone (DMBQ) is the major bioactive compound in FWGE and is probably responsible for its anticancer activity. The second objective of this study was to compare the antiproliferative properties in vitro of FWGE and the DMBQ compound.
Methods
The IC\(_{50}\) values of FWGE were determined for nine human cancer cell lines after 24 h of culture. The DMBQ compound was used at a concentration of 24 μmol/l, which is equal to the molar concentration of DMBQ in FWGE. Cell viability, cell cycle, cellular redox state, glucose consumption, lactic acid production, cellular ATP levels, and the NADH/NAD\(^+\) ratio were measured.
Results
The mean IC\(_{50}\) value of FWGE for the nine human cancer cell lines tested was 10 mg/ml. Both FWGE (10 mg/ml) and the DMBQ compound (24 μmol/l) induced massive cell damage within 24 h after starting treatment, with changes in the cellular redox state secondary to formation of intracellular reactive oxygen species. Unlike the DMBQ compound, which was only cytotoxic, FWGE exhibited cytostatic and growth delay effects in addition to cytotoxicity. Both cytostatic and growth delay effects were linked to impaired glucose utilization which influenced the cell cycle, cellular ATP levels, and the NADH/NAD\(^+\) ratio. The growth delay effect in response to FWGE treatment led to induction of autophagy.
Conclusions
FWGE and the DMBQ compound both induced oxidative stress-promoted cytotoxicity. In addition, FWGE exhibited cytostatic and growth delay effects associated with impaired glucose utilization which led to autophagy, a possible previously unknown mechanism behind the influence of FWGE on cancer cell metabolism.
Background
Multimodal treatment strategies – perioperative chemotherapy (CTx) and radical surgery – are currently accepted as treatment standard for locally advanced gastric cancer. However, the role of adjuvant postoperative CTx (postCTx) in addition to neoadjuvant preoperative CTx (preCTx) in this setting remains controversial.
Methods
Between 4/2006 and 12/2013, 116 patients with locally advanced gastric cancer were treated with preCTx. 72 patients (62 %), in whom complete tumor resection (R0, subtotal/total gastrectomy with D2-lymphadenectomy) was achieved, were divided into two groups, one of which receiving adjuvant therapy (n = 52) and one without (n = 20). These groups were analyzed with regard to survival and exclusion criteria for adjuvant therapy.
Results
Postoperative complications, as well as their severity grade, did not correlate with fewer postCTx cycles administered (p = n.s.). Long-term survival was shorter in patients receiving postCTx in comparison to patients without postCTx, but did not show statistical significance. In per protocol analysis by excluding two patients with perioperative death, a shorter 3-year survival rate was observed in patients receiving postCTx compared to patients without postCTx (3-year survival: 71.2 % postCTx group vs. 90.0 % non-postCTx group; p = 0.038).
Conclusion
These results appear contradicting to the anticipated outcome. While speculative, they question the value of post-CTx. Prospectively randomized studies are needed to elucidate the role of postCTx.
Background
The vascular type represents a very rare, yet the clinically most fatal entity of Ehlers-Danlos syndrome (EDS). Patients are often admitted due to arterial bleedings and the friable tissue and the altered coagulation contribute to the challenge in treatment strategies. Until now there is little information about clotting characteristics that might influence hemostasis decisively and eventually worsen emergency situations.
Results
22 vascular type EDS patients were studied for hemoglobin, platelet volume and count, Quick and activated partial thromboplastin time, fibrinogen, factor XIII, von Willebrand disease, vitamin D and platelet aggregation by modern standard laboratory methods. Results show a high prevalence of over 50 % for platelet aggregation disorders in vascular type EDS patients, especially for collagen and epinephrine induced tests, whereas the plasmatic cascade did not show any alterations. Additionally, more than half of the tested subjects showed low vitamin D serum levels, which might additionally affect vascular wall integrity.
Conclusion
The presented data underline the importance of detailed laboratory screening methods in vascular type EDS patients in order to allow for targeted application of platelet-interacting substances that might be of decisive benefit in the emergency setting.
Background
Anastomotic leakage (AL) is one of the most common and serious complications following visceral surgery. In recent years, endoluminal vacuum therapy has dramatically changed therapeutic options for AL, but its use has been limited to areas easily accessible by endoscope.
Case presentation
We describe the first use of endoluminal vacuum therapy in the small intestine employing a combined surgical and endoscopic “rendezvous technique” in which the surgeon assists the endoscopic placement of an endoluminal vacuum therapy sponge in the jejunum by means of a pullback string. This technique led to a completely closed AL after 27 days and 7 changes of the endosponge.
Conclusion
The combined surgical and endoscopic rendezvous technique can be useful in cases of otherwise difficult endosponge placement.
Purpose: In hepatocellular carcinoma patients with large or multinodal tumors, where curative treatment options are not feasible, transarterial therapies play a major role. Transarterial chemoembolization (TACE) with drug-eluting beads (DEB-TACE) is a promising new approach due to higher intratumoral and lower systemic concentration of the chemotherapeutic agent compared to conventional TACE (cTACE).
Patients and methods: In a retrospective analysis, 32 patients with hepatocellular carcinoma who received either DEB or a cTACE were compared regarding survival time, disease recurrence, and side effects such as pain and fever.
Results: No significant differences could be detected between the cTACE and DEB-TACE groups with regard to mean hospital stay, appearance of postinterventional fever, or 30-day mortality. However, the application of intravenous analgesics as postinterventional pain medication was needed more often in patients treated with DEB-TACE (57.1% vs 12.5%, P=0.0281). The overall median survival after the initial procedure was 10.8 months in the cTACE group and 9.2 months in the DEB-TACE group, showing no significant difference.
Conclusion: No survival benefit for patients treated with either DEB-TACE or cTACE was observed. Surprisingly, a higher rate of postinterventional pain could be detected after DEB-TACE.
Platelet-derived growth factor (PDGF) and signaling via its receptors plays a crucial role in tumor cell proliferation and thus may represent an attractive target besides VEGF/EGFR-based antibody therapies. In this study we analyzed the influence of PDGF in colorectal cancer. PDGF was expressed intensively in early and even more intensively in late stage primary CRCs. Like VEGF, PDGF enhanced human colon cancer proliferation, and increased oxidative glycolytic activity, and activated HIF1α and c-Myc in vitro. PDGF activated the PI3K/Akt/mTOR pathway while leaving MAPK signaling untouched. Further dissection showed that inhibition of Akt strongly impeded cancer cell growth while inhibition of PI3K did not. MAPK analysis suggested an inhibitory crosstalk between both pathways, thus explaining the different effects of the Akt and PI3K inhibitors on cancer cell proliferation. PDGF stimulates colon cancer cell proliferation, and prevents inhibitor induced apoptosis, resulting in tumor growth. Therefore inhibition of PDGF signaling seems to be a promising target in colorectal cancer therapy. However, due to the multifaceted nature of the intracellular PDGF signaling, careful intervention strategies are needed when looking into specific signaling pathways like PI3K/Akt/mTOR and MAPK.
Toll like receptor (TLR) signaling has been suggested to play an important role in the inflammatory microenvironment of solid tumors and through this inflammation-mediated tumor growth. Here, we studied the role of tumor cells in their process of self-maintaining TLR expression independent of inflammatory cells and cytokine milieu for autoregulative tumor growth signaling in pancreatic cancer. We analyzed the expression of TLR2, -4, and -9 in primary human cancers and their impact on tumor growth via induced activation in several established pancreatic cancers. TLR-stimulated pancreatic cancer cells were specifically investigated for activated signaling pathways of VEGF/PDGF and anti-apoptotic Bcl-xL expression as well as tumor cell growth. The primary pancreatic cancers and cell lines expressed TLR2, -4, and -9. TLR-specific stimulation resulted in activated MAP-kinase signaling, most likely via autoregulative stimulation of demonstrated TLR-induced VEGF and PDGF expression. Moreover, TLR activation prompted the expression of Bcl-xL and has been demonstrated for the first time to induce tumor cell proliferation in pancreatic cancer. These findings strongly suggest that pancreatic cancer cells use specific Toll like receptor signaling to promote tumor cell proliferation and emphasize the particular role of TLR2, -4, and -9 in this autoregulative process of tumor cell activation and proliferation in pancreatic cancer.
Tumor models based on cancer cell lines cultured two-dimensionally (2D) on plastic lack histological complexity and functionality compared to the native microenvironment. Xenogenic mouse tumor models display higher complexity but often do not predict human drug responses accurately due to species-specific differences. We present here a three-dimensional (3D) in vitro colon cancer model based on a biological scaffold derived from decellularized porcine jejunum (small intestine submucosa+mucosa, SISmuc). Two different cell lines were used in monoculture or in coculture with primary fibroblasts. After 14 days of culture, we demonstrated a close contact of human Caco2 colon cancer cells with the preserved basement membrane on an ultrastructural level as well as morphological characteristics of a well-differentiated epithelium. To generate a tissue-engineered tumor model, we chose human SW480 colon cancer cells, a reportedly malignant cell line. Malignant characteristics were confirmed in 2D cell culture: SW480 cells showed higher vimentin and lower E-cadherin expression than Caco2 cells. In contrast to Caco2, SW480 cells displayed cancerous characteristics such as delocalized E-cadherin and nuclear location of beta-catenin in a subset of cells. One central drawback of 2D cultures-especially in consideration of drug testing-is their artificially high proliferation. In our 3D tissue-engineered tumor model, both cell lines showed decreased numbers of proliferating cells, thus correlating more precisely with observations of primary colon cancer in all stages (UICC I-IV). Moreover, vimentin decreased in SW480 colon cancer cells, indicating a mesenchymal to epithelial transition process, attributed to metastasis formation. Only SW480 cells cocultured with fibroblasts induced the formation of tumor-like aggregates surrounded by fibroblasts, whereas in Caco2 cocultures, a separate Caco2 cell layer was formed separated from the fibroblast compartment beneath. To foster tissue generation, a bioreactor was constructed for dynamic culture approaches. This induced a close tissue-like association of cultured tumor cells with fibroblasts reflecting tumor biopsies. Therapy with 5-fluorouracil (5-FU) was effective only in 3D coculture. In conclusion, our 3D tumor model reflects human tissue-related tumor characteristics, including lower tumor cell proliferation. It is now available for drug testing in metastatic context-especially for substances targeting tumor-stroma interactions.
Background
Currently ketogenic diets (KDs) are hyped as an anti-tumor intervention aimed at exploiting the metabolic abnormalities of cancer cells. However, while data in humans is sparse, translation of murine tumor models to the clinic is further hampered by small sample sizes, heterogeneous settings and mixed results concerning tumor growth retardation. The aim was therefore to synthesize the evidence for a growth inhibiting effect of KDs when used as a monotherapy in mice.
Methods
We conducted a Bayesian random effects meta-analysis on all studies assessing the survival (defined as the time to reach a pre-defined endpoint such as tumor volume) of mice on an unrestricted KD compared to a high carbohydrate standard diet (SD). For 12 studies meeting the inclusion criteria either a mean survival time ratio (MR) or hazard ratio (HR) between the KD and SD groups could be obtained. The posterior estimates for the MR and HR averaged over four priors on the between-study heterogeneity τ\(^{2}\) were MR = 0.85 (95% highest posterior density interval (HPDI) = [0.73, 0.97]) and HR = 0.55 (95% HPDI = [0.26, 0.87]), indicating a significant overall benefit of the KD in terms of prolonged mean survival times and reduced hazard rate. All studies that used a brain tumor model also chose a late starting point for the KD (at least one day after tumor initiation) which accounted for 26% of the heterogeneity. In this subgroup the KD was less effective (MR = 0.89, 95% HPDI = [0.76, 1.04]).
Conclusions
There was an overall tumor growth delaying effect of unrestricted KDs in mice. Future experiments should aim at differentiating the effects of KD timing versus tumor location, since external evidence is currently consistent with an influence of both of these factors.
Bariatric operations in obese patients with type 2 diabetes often improve diabetes before weight loss is observed. In patients mainly Roux-en-Y-gastric bypass with partial stomach resection is performed. Duodenojejunal bypass (DJB) and ileal interposition (IIP) are employed in animal experiments. Due to increased glucose exposition of L-cells located in distal ileum, all bariatric surgery procedures lead to higher secretion of antidiabetic glucagon like peptide-1 (GLP-1) after glucose gavage. After DJB also downregulation of Na\(^{+}\)-D-glucose cotransporter SGLT1 was observed. This suggested a direct contribution of decreased glucose absorption to the antidiabetic effect of bariatric surgery. To investigate whether glucose absorption is also decreased after IIP, we induced diabetes with decreased glucose tolerance and insulin sensitivity in male rats and investigated effects of IIP on diabetes and SGLT1. After IIP, we observed weight-independent improvement of glucose tolerance, increased insulin sensitivity, and increased plasma GLP-1 after glucose gavage. The interposed ileum was increased in diameter and showed increased length of villi, hyperplasia of the epithelial layer, and increased number of L-cells. The amount of SGLT1-mediated glucose uptake in interposed ileum was increased 2-fold reaching the same level as in jejunum. Thus, improvement of glycemic control by bariatric surgery does not require decreased glucose absorption.
Peroral endoscopic myotomy (POEM) is a new endoscopic treatment for achalasia with very good short-term results in adults. Data about POEM in pediatric patients are missing. We present the case of a 10-year-old male patient with type I (classic) achalasia, successfully treated with POEM. The procedure was accomplished in a similar fashion to the technique used in adults. Short-term results were fine, with a complete control of dysphagia and absence of reflux. We suggest that POEM is a suitable option in pediatric patients—similar to adults—but long-term results must be awaited.
Background
Solitary metastases to the pancreas are rare. Therefore the value of resection in curative intention remains unclear. In the literature there are several promising reports about resection of solitary metastasis to the pancreas mainly of renal origin.
Case presentation
Here we report for the first time on the surgical therapy of a 1.5 cm solitary pancreatic metastasis of an adrenocortical carcinoma. The metastasis occurred almost 6 years after resection of the primary tumor. A partial pancreatoduodenectomy was performed and postoperatively adjuvant mitotane treatment was initiated. During the follow-up of 3 years after surgery no evidence of tumor recurrence occurred.
Conclusion
Resection of pancreatic tumors should be considered, even if the mass is suspicious for metastatic disease including recurrence of adrenocortical cancer.
Balanced hydroxyethylstarch (HES 130/0.4) impairs kidney function in-vivo without inflammation
(2015)
Volume therapy is a standard procedure in daily perioperative care, and there is an ongoing discussion about the benefits of colloid resuscitation with hydroxyethylstarch (HES). In sepsis HES should be avoided due to a higher risk for acute kidney injury (AKI). Results of the usage of HES in patients without sepsis are controversial. Therefore we conducted an animal study to evaluate the impact of 6% HES 130/0.4 on kidney integrity with sepsis or under healthy conditions Sepsis was induced by standardized Colon Ascendens Stent Peritonitis (sCASP). sCASP-group as well as control group (C) remained untreated for 24 h. After 18 h sCASP+HES group (sCASP+VOL) and control+HES (C+VOL) received 50 ml/KG balanced 6% HES (VOL) 130/0.4 over 6h. After 24h kidney function was measured via Inulin- and PAH-Clearance in re-anesthetized rats, and serum urea, creatinine (crea), cystatin C and Neutrophil gelatinase-associated lipocalin (NGAL) as well as histopathology were analysed. In vitro human proximal tubule cells (PTC) were cultured +/- lipopolysaccharid (LPS) and with 0.1–4.0% VOL. Cell viability was measured with XTT-, cell toxicity with LDH-test. sCASP induced severe septic AKI demonstrated divergent results regarding renal function by clearance or creatinine measure focusing on VOL. Soleley HES (C+VOL) deteriorated renal function without sCASP. Histopathology revealed significantly derangements in all HES groups compared to control. In vitro LPS did not worsen the HES induced reduction of cell viability in PTC cells. For the first time, we demonstrated, that application of 50 ml/KG 6% HES 130/0.4 over 6 hours induced AKI without inflammation in vivo. Severity of sCASP induced septic AKI might be no longer susceptible to the way of volume expansion
Immunity, Inflammation and Cancer: The role of Foxp3, TLR7 and TLR8 in gastrointestinal cancer
(2015)
Regulatory T cells (Treg) expressing the transcription factor forkhead box protein P3 (Foxp3) have been demonstrated to mediate evasion from anti-tumor immune responses during tumor progression. Moreover, Foxp3 expression by tumor cells themselves may allow them to counteract effector T cell responses, resulting in a survival benefit of the tumor. For gastrointestinal cancers, in particular pancreatic and colorectal cancer (CRC), the clinical relevance of Foxp3 is not clear to date. Therefore the aim of this study was to analyze its impact in CRC and pancreatic cancer. To determine the relevance of Foxp3 for tumor progression and patient survival, gene and protein analysis of human pancreatic and colon cancer cell lines as well as tumor tissues from patients with CRC was performed. The results derived from the patients with CRC were correlated with clinicopathological parameters and patients’ overall survival. Cancer cell mediated Foxp3 expression in vitro was demonstrated in human pancreatic cancer cell lines PANC1, PaCa DD 135, PaCa DD 159 and PaCa DD 185 as well as in human colon cancer cell lines SW480 and SW620. Additionally, Foxp3 expressing cancer cells were found in ex vivo tumor tissue samples of patients with CRC. The percentage of Foxp3+ cancer cells increased from stages UICC I/II to UICC III/IV compared to normal tissue. Moreover, high tumor cell mediated Foxp3 expression was associated with poor prognosis compared to patients with low Foxp3 expression. In contrast, low and high Foxp3 level in tumor infiltrating Treg cells demonstrated no significant differences in patients’ overall survival. Correlation analysis demonstrated a significant association of Foxp3 cancer cell expression with the expression of immunosuppressive cytokines IL-10 and TGF-β. These findings suggest that Immunosuppressive cytokines such as IL-10 and TGF-β released by rather Foxp3+ cancer cells than Foxp3+ Treg cells may inhibit the activation of naive T cells, hence limiting antitumor immune responses and favoring tumorigenesis and progression.
Chronic inflammation has been shown to be an important epigenetic and environmental factor in numerous tumor entities. Recent data suggest that tumorigenesis and tumor progression may be associated with inflammation-triggered activation of Toll-like receptors (TLR). In this study, the specific impact of both TLR7 and TLR8 expression and signaling on tumor cell proliferation and chemoresistance is analyzed in inflammation linked CRC and pancreatic cancer. By gene and protein expression analysis of human pancreatic and colon cancer cell lines TLR7 and TLR8 expression was determined in vitro. Additionally, expression of TLR7/TLR8 in UICC stage I-IV pancreatic cancer, chronic pancreatitis and normal pancreatic tissue was examined. For in vitro/in vivo studies TLR7/TLR8 overexpressing PANC1 cell lines were generated and analyzed for effects of TLR expression and stimulation on tumor cell proliferation and chemoresistance. Cancer cell mediated TLR7 and TLR8 expression in vitro was demonstrated in human colon cancer cell lines SW480, SW620 and HT-29 as well as in primary pancreatic cancer cell lines PaCa DD 135, PaCa DD 159 and PaCa DD 185. Additionally, TLR7 and TLR8 expressing tumor cells were found in ex vivo tissue samples of patients with pancreatic cancer and chronic pancreatitis. Significantly elevated expression levels of TLR7 and TLR8 were found in advanced tumor stages (UICC III) compared to early tumor stages (UICC II) and chronic pancreatitis. No or occasionally low expression was detected in normal pancreatic tissue. In contrast to the tissues from patients with pancreatic cancer or chronic pancreatitis, established pancreatic tumor cell lines express only very low levels of TLR7 and TLR8. Therefore, for in vitro and xenograft studies TLR7 or TLR8 overexpressing PANC1 cells were generated. Proliferation promoting effects of TLR7 and TLR8 expression and stimulation with R848 were detected in vitro. Additionally, increased tumor growth of TLR expressing PANC1 cells was demonstrated in subcutaneously injected Balb/c nude mice. Interestingly, activation of TLR7 or TLR8 induced not only an increase in tumor cell proliferation but also a strong chemoresistance of PANC1 cells against 5-fluorouracil (5-FU). Moreover, treatment with R848 resulted in elevated expression levels of NF-κB, COX-2 and inflammatory cytokines IL-1β, IL-8 and TNF-α, suggesting TLR7/8 signaling to contribute to an inflammatory, anti-apoptotic and proliferation promoting tumor microenvironment. These findings emphasize the particular role of TLR7 and TLR8 in inflammation related cancers and their relevance as potential targets for cancer therapy.
Background
Comprehensive evidence on the incidence, time course and independent risk factors of metachronous peritoneal carcinomatosis (metaPC) in gastric cancer patients treated with curative intent in the context of available systemic combination chemotherapies is lacking.
Methods
Data from a prospectively collected single-institutional Center Cancer Registry with 1108 consecutive patients with gastric adenocarcinoma (GC), clinical, histological and survival data were analyzed for independent risk factors and prognosis with focus on the development of metaPC. Findings were then stratified to the time periods of treatment with surgery alone, 5-Fluorouracil-only and contemporary combined systemic perioperative chemotherapy strategies, respectively.
Results
Despite R0 D2 gastrectomy (n = 560), 49.6% (±5.4%) of the patients were diagnosed with tumour recurrence and 15.5% (±1.8%) developed metaPC after a median time of 17.7 (15.1-20.3) months after surgery resulting in a tumour related mortality of 100% with a median survival of 3.0 months (2.1 – 4.0). Independent risk factors for the development of metaPC were serosa positive T-category, nodal positive-status, signet cell and undifferentiated gradings (G3/G4). Contemporary systemic combination chemotherapy did not improve the incidence and prognosis of metaPC (p = 0.54).
Conclusions
Despite significant improvements in the overall survival for the complete cohort with gastric cancer over time, those patients with metaPC did not experience the same benefits. The lack of change in the incidence, and persistent poor prognosis of metaPC after curative surgery expose the need for further prevention and/or improved treatment options for this devastating condition.
In vitro evidence for senescent multinucleated melanocytes as a source for tumor-initiating cells
(2015)
Oncogenic signaling in melanocytes results in oncogene-induced senescence (OIS), a stable cell-cycle arrest frequently characterized by a bi-or multinuclear phenotype that is considered as a barrier to cancer progression. However, the long-sustained conviction that senescence is a truly irreversible process has recently been challenged. Still, it is not known whether cells driven into OIS can progress to cancer and thereby pose a potential threat. Here, we show that prolonged expression of the melanoma oncogene N-RAS\(^{61K}\) in pigment cells overcomes OIS by triggering the emergence of tumor-initiating mononucleated stem-like cells from senescent cells. This progeny is dedifferentiated, highly proliferative, anoikis-resistant and induces fast growing, metastatic tumors. Our data describe that differentiated cells, which are driven into senescence by an oncogene, use this senescence state as trigger for tumor transformation, giving rise to highly aggressive tumor-initiating cells. These observations provide the first experimental in vitro evidence for the evasion of OIS on the cellular level and ensuing transformation.
Objective: To investigate the impact of the phophodiesterase-4 inhibition (PD-4-I) with rolipram on hepatic integrity in lipopolysaccharide (LPS) induced hyperinflammation. Materials and Methods: Liver microcirculation in rats was obtained using intravital microscopy. Macrohemodynamic parameters, blood assays, and organs were harvested to determine organ function and injury. Hyperinflammation was induced by LPS and PD-4-I rolipram was administered intravenously one hour after LPS application. Cell viability of HepG2 cells was measured by EZ4U-kit based on the dye XTT. Experiments were carried out assessing the influence of different concentrations of tumor necrosis factor alpha (TNF-α) and LPS with or without PD-4-I. Results: Untreated LPS-induced rats showed significantly decreased liver microcirculation and increased hepatic cell death, whereas LPS + PD-4-I treatment could improve hepatic volumetric flow and cell death to control level whithout influencing the inflammatory impact. In HepG2 cells TNF-α and LPS significantly reduced cell viability. Coincubation with PD-4-I increased HepG2 viability to control levels. The heme oxygenase 1 (HO-1) pathway did not induce the protective effect of PD-4-I. Conclusion: Intravenous PD-4-I treatment was effective in improving hepatic microcirculation and hepatic integrity, while it had a direct protective effect on HepG2 viability during inflammation.
Cell-based strategies represent a new frontier in the treatment of immune-mediated disorders. However, the paucity of markers for isolation of molecularly defined immunomodulatory cell populations poses a barrier to this field. Here, we show that ATP-binding cassette member B5 (ABCB5) identifies dermal immunoregulatory cells (DIRCs) capable of exerting therapeutic immunoregulatory functions through engagement of programmed cell death 1 (PD-1). Purified Abcb5\(^+\) DIRCs suppressed T cell proliferation, evaded immune rejection, homed to recipient immune tissues, and induced Tregs in vivo. In fully major-histocompatibility-complex-mismatched cardiac allotransplantation models, allogeneic DIRCs significantly prolonged allograft survival. Blockade of DIRC-expressed PD-1 reversed the inhibitory effects of DIRCs on T cell activation, inhibited DIRC-dependent Treg induction, and attenuated DIRC-induced prolongation of cardiac allograft survival, indicating that DIRC immunoregulatory function is mediated, at least in part, through PD-1. Our results identify ABCB5\(^+\) DIRCs as a distinct immunoregulatory cell population and suggest promising roles of this expandable cell subset in cellular immunotherapy.
Clinical prognosis of metastasized colorectal carcinoma (CRC) is still not at desired levels and novel drugs are needed. Here, we focused on the multi-tyrosine kinase inhibitor E7080 (Lenvatinib) and assessed its therapeutic efficacy against human CRC cell lines in vitro and human CRC xenografts in vivo. The effect of E7080 on cell viability was examined on 10 humanCRCcell lines and humanendothelial cells (HUVEC). The inhibitory effect of E7080 on VEGF-induced angiogenesis was studied in an ex vivo mouse aortic ring angiogenesis assay. In addition, the efficacy of E7080 against xenografts derived fromCRC cell lines and CRC patient resection specimenswithmutated KRASwas investigated in vivo. Arelatively low cytotoxic effect of E7080 on CRC cell viabilitywas observed in vitro. Endothelial cells (HUVEC)weremore susceptible to the incubation with E7080. This is in line with the observation that E7080 demonstrated an anti-angiogenic effect in a three-dimensional ex vivo mouse aortic ring angiogenesis assay. E7080 effectively disrupted CRC cell-mediated VEGF-stimulated growth of HUVEC in vitro. Daily in vivo treatment with E7080 (5 mg/kg) significantly delayed the growth of KRAS mutated CRC xenografts with decreased density of tumor-associated vessel formations and without tumor regression. This observation is in line with results that E7080 did not significantly reduce the number of Ki67-positive cells in CRC xenografts. The results suggest antiangiogenic activity of E7080 at a dosage thatwas well tolerated by nudemice. E7080 may provide therapeutic benefits in the treatment of CRC with mutated KRAS.
Guidelines are increasingly determining the decision process in day-to-day clinical work. Guidelines describe the current best possible standard in diagnostics and therapy. They should be developed by an international panel of experts, whereby alongside individual experience, above all, the results of comparative studies are decisive. According to the results of high-ranking scientific studies published in peer-reviewed journals, statements and recommendations are formulated, and these are graded strictly according to the criteria of evidence-based medicine. Guidelines can therefore be valuable in helping particularly the young surgeon in his or her day-to-day work to find the best decision for the patient when confronted with a wide and confusing range of options. However, even experienced surgeons benefit because by virtue of a heavy workload and commitment, they often find it difficult to keep up with the ever-increasing published literature. All guidelines require regular updating, usually every 3 years, in line with progress in the field. The current Guidelines focus on technique and perioperative management of laparoscopic ventral hernia repair and constitute the first comprehensive guidelines on this topic. In this issue of Surgical Endoscopy, the first part of the Guidelines is published including sections on basics, indication for surgery, perioperative management, and key points of technique. The next part (Part 2) of the Guidelines will address complications and comparisons between open and laparoscopic techniques. Part 3 will cover mesh technology, hernia prophylaxis, technique-related issues, new technologic developments, lumbar and other unusual hernias, and training/education.
Guidelines are increasingly determining the decision process in day-to-day clinical work. Guidelines describe the current best possible standard in diagnostics and therapy. They should be developed by an international panel of experts, whereby alongside individual experience, above all, the results of comparative studies are decisive. According to the results of high-ranking scientific studies published in peer-reviewed journals, statements and recommendations are formulated, and these are graded strictly according to the criteria of evidence-based medicine. Guidelines can therefore be valuable in helping particularly the young surgeon in his or her day-to-day work to find the best decision for the patient when confronted with a wide and confusing range of options. However, even experienced surgeons benefit because by virtue of a heavy workload and commitment, they often find it difficult to keep up with the ever-increasing published literature. All guidelines require regular updating, usually every 3 years, in line with progress in the field. The current Guidelines focus on technique and perioperative management of laparoscopic ventral hernia repair and constitute the first comprehensive guidelines on this topic. In this issue of Surgical Endoscopy, the first part of the Guidelines is published including sections on basics, indication for surgery, perioperative management, and key points of technique. The next part (Part 2) of the Guidelines will address complications and comparisons between open and laparoscopic techniques. Part 3 will cover mesh technology, hernia prophylaxis, technique-related issues, new technologic developments, lumbar and other unusual hernias, and training/education.
Guidelines are increasingly determining the decision process in day-to-day clinical work. Guidelines describe the current best possible standard in diagnostics and therapy. They should be developed by an international panel of experts, whereby alongside individual experience, above all, the results of comparative studies are decisive. According to the results of high-ranking scientific studies published in peer-reviewed journals, statements and recommendations are formulated, and these are graded strictly according to the criteria of evidence-based medicine. Guidelines can therefore be valuable in helping particularly the young surgeon in his or her day-to-day work to find the best decision for the patient when confronted with a wide and confusing range of options. However, even experienced surgeons benefit because by virtue of a heavy workload and commitment, they often find it difficult to keep up with the ever-increasing published literature. All guidelines require regular updating, usually every 3 years, in line with progress in the field. The current Guidelines focus on technique and perioperative management of laparoscopic ventral hernia repair and constitute the first comprehensive guidelines on this topic. In this issue of Surgical Endoscopy, the first part of the Guidelines is published including sections on basics, indication for surgery, perioperative management, and key points of technique. The next part (Part 2) of the Guidelines will address complications and comparisons between open and laparoscopic techniques. Part 3 will cover mesh technology, hernia prophylaxis, technique-related issues, new technologic developments, lumbar and other unusual hernias, and training/education.
Background
Up to 50% of septic patients develop acute kidney injury (AKI). The pathomechanism of septic AKI is poorly understood. Therefore, we established an innovative rodent model to characterize sepsis-induced AKI by standardized colon ascendens stent peritonitis (sCASP). The model has a standardized focus of infection, an intensive care set up with monitoring of haemodynamics and oxygenation resulting in predictable impairment of renal function, AKI parameters as well as histopathology scoring.
Methods
Anaesthetized rats underwent the sCASP procedure, whereas sham animals were sham operated and control animals were just monitored invasively. Haemodynamic variables and blood gases were continuously measured. After 24 h, animals were reanesthetized; cardiac output (CO), inulin and PAH clearances were measured and later on kidneys were harvested; and creatinine, urea, cystatin C and neutrophil gelatinase-associated lipocalin (NGAL) were analysed. Additional sCASP-treated animals were investigated after 3 and 9 days.
Results
All sCASP-treated animals survived, whilst ubiquitous peritonitis and significantly deteriorated clinical and macrohaemodynamic sepsis signs after 24 h (MAP, CO, heart rate) were obvious. Blood analyses showed increased lactate and IL-6 levels as well as leucopenia. Urine output, inulin and PAH clearance were significantly decreased in sCASP compared to sham and control. Additionally, significant increase in cystatin C and NGAL was detected. Standard parameters like serum creatinine and urea were elevated and sCASP-induced sepsis increased significantly in a time-dependent manner. The renal histopathological score of sCASP-treated animals deteriorated after 3 and 9 days.
Conclusions
The presented sCASP method is a standardized, reliable and reproducible method to induce septic AKI. The intensive care set up, continuous macrohaemodynamic and gas exchange monitoring, low mortality rate as well as the opportunity of detailed analyses of kidney function and impairments are advantages of this setup. Thus, our described method may serve as a new standard for experimental investigations of septic AKI.
The prognosis of patients with locally advanced pancreatic cancer can be improved if secondary complete (R0) resection is possible. In patients initially staged as unresectable this may be achieved with neoadjuvant treatment which is usually chemoradiotherapy based. We report the case of a 46-year-old patient with an unresectable, locally advanced pancreatic cancer (pT4 Nx cM0 G2) who was treated with a sequential neoadjuvant chemotherapy regimen consisting of 2 cycles of nab-paclitaxel plus gemcitabine followed by 4 cycles of FOLFIRINOX. Neoadjuvant chemotherapy resulted in secondary resectability (R0 resection). After 2 cycles of nab-paclitaxel plus gemcitabine, the patient already had a complete metabolic remission as measured by integrated fludeoxyglucose ((18)F) positron emission tomography and computerized tomography. After a follow-up of 18 months the patient is alive without progression of disease. We propose to assess the clinical benefit of sequencing the combinations nab-paclitaxel plus gemcitabine and FOLFIRINOX as neoadjuvant therapy for patients with locally advanced and initially unresectable pancreatic cancer in a controlled clinical trial.
Objective: To determine whether rats reaching the same body mass, having been fed either a low-fat (LFD) or a high-fat diet (HFD), differ in white adipose tissue (WAT) deposition. Methods: In experiment 1, 22 Sprague-Dawley rats of the same age were divided into 11 rats with body mass below the batch median and fed a HFD, and 11 above the median and fed a LFD. In experiment 2, 20 Sprague-Dawley rats of the same age and starting body mass were randomised to either a HFD or LFD. When all groups reached similar final body mass, WAT was quantified using magnetic resonance imaging (MRI), dissection, and plasma leptin. Results: In experiment 1, both groups reached similar final body mass at the same age; in experiment 2 the HFD group reached similar final body mass earlier than the LFD group. There were no significant differences in WAT as assessed by MRI or leptin between the HFD and LFD groups in both experiments. Dissection revealed a trend for higher retroperitoneal and epididymal adiposity in the HFD groups in both experiments. Conclusions: We conclude that at similar body mass, adiposity is independent of the macronutrient composition of the feeding regimen used to achieve it. (C) 2014 S Karger GmbH, Freiburg
Background
The management of rectal cancer (RC) has substantially changed over the last decades with the implementation of neoadjuvant chemoradiotherapy, adjuvant therapy and improved surgery such as total mesorectal excision (TME). It remains unclear in which way these approaches overall influenced the rate of local recurrence and overall survival.
Methods
Clinical, histological and survival data of 658 out of 662 consecutive patients with RC were analyzed for treatment and prognostic factors from a prospectively expanded single-institutional database. Findings were then stratified according to time of diagnosis in patient groups treated between 1993 and 2001 and 2002 and 2010.
Results
The study population included 658 consecutive patients with rectal cancer between 1993 and 2010. Follow up data was available for 99.6% of all 662 treated patients. During the time period between 2002 and 2010 significantly more patients underwent neoadjuvant chemoradiotherapy (17.6% vs. 60%) and adjuvant chemotherapy (37.9% vs. 58.4%). Also, the rate of reported TME during surgery increased. The rate of local or distant metastasis decreased over time, and tumor related 5-year survival increased significantly with from 60% to 79%.
Conclusion
In our study population, the implementation of treatment changes over the last decade improved the patient’s outcome significantly. Improvements were most evident for UICC stage III rectal cancer.
Background
Reliable central venous access (CVC) is essential for hematology–oncology patients since frequent puncture of peripheral veins—e.g., for chemotherapy, antibiotic administration, repeated blood sampling, and monitoring—can cause unacceptable pain and psychological trauma, as well as severe side effects in cases of extravasation of chemotherapy drugs. However, CVC lines still carry major risk factors, including thrombosis, infection (e.g., entry site, tunnel, and luminal infections), and catheter dislocation, leakage, or breakage.
Methods
Here we performed a retrospective database analysis to determine the incidence of CVC-associated thrombosis in a single-center cohort of 448 pediatric oncologic patients, and to analyze whether any subgroup of patients was at increased risk and thus might benefit from prophylactic anticoagulation.
Results
Of the 448 patients, 269 consecutive patients received a CVC, and 55 of these 269 patients (20%) also had a thrombosis. Of these 55 patients, 43 had at least one CVC-associated thrombosis (total number of CVC-associated thrombosis: n = 52). Among all patients, the median duration of CVC exposure was 464 days. Regarding exposure time, no significant difference was found between patients with and without CVC-associated thrombosis. Subclavia catheters and advanced tumor stages seem to be the main risk factors for the development of CVC-associated thrombosis, whereas pharmacologic prophylaxis did not seem to have a relevant impact on the rate of thrombosis.
Conclusions
We conclude that pediatric surgeons and oncologists should pay close attention to ensuring optimal and accurate CVC placement, as this appears the most effective tool to minimize CVC-associated complications.
Background
Measles virus (MV) causes T cell suppression by interference with phosphatidylinositol-3-kinase (PI3K) activation. We previously found that this interference affected the activity of splice regulatory proteins and a T cell inhibitory protein isoform was produced from an alternatively spliced pre-mRNA.
Hypothesis
Differentially regulated and alternatively splice variant transcripts accumulating in response to PI3K abrogation in T cells potentially encode proteins involved in T cell silencing.
Methods
To test this hypothesis at the cellular level, we performed a Human Exon 1.0 ST Array on RNAs isolated from T cells stimulated only or stimulated after PI3K inhibition. We developed a simple algorithm based on a splicing index to detect genes that undergo alternative splicing (AS) or are differentially regulated (RG) upon T cell suppression.
Results
Applying our algorithm to the data, 9% of the genes were assigned as AS, while only 3% were attributed to RG. Though there are overlaps, AS and RG genes differed with regard to functional regulation, and were found to be enriched in different functional groups. AS genes targeted extracellular matrix (ECM)-receptor interaction and focal adhesion pathways, while RG genes were mainly enriched in cytokine-receptor interaction and Jak-STAT. When combined, AS/RG dependent alterations targeted pathways essential for T cell receptor signaling, cytoskeletal dynamics and cell cycle entry.
Conclusions
PI3K abrogation interferes with key T cell activation processes through both differential expression and alternative splicing, which together actively contribute to T cell suppression.
Arterial embolism with lower limb ischemia is a rare manifestation of paraneoplastic hypercoagulability in cancer patients. We report a unique case of fatal thromboembolism involving both circulations associated with a poorly differentiated neuroendocrine tumor of the lung with rapid progress despite high doses of unfractioned heparin and review the current literature on anticoagulative regimen in tumour patients.
The cancerous inhibitor of protein phosphatase 2A (CIP2A) is an oncogenic factor that stabilises the c-Myc protein. CIP2A is overexpressed in several tumours, and expression levels are an independent marker for long-term outcome. To determine whether CIP2A expression is elevated in colon cancer and whether it might serve as a prognostic marker for survival, we analysed CIP2A mRNA expression by real-time PCR in 104 colon cancer samples. CIP2A mRNA was overexpressed in colon cancer samples and CIP2A expression levels correlated significantly with tumour stage. We found that CIP2A serves as an independent prognostic marker for disease-free and overall survival. Further, we investigated CIP2A-dependent effects on levels of c-Myc, Akt and on cell proliferation in three colon cancer cell lines by silencing CIP2A using small interfering (si) and short hairpin (sh) RNAs. Depletion of CIP2A substantially inhibited growth of colon cell lines and reduced c-Myc levels without affecting expression or function of the upstream regulatory kinase, Akt. Expression of CIP2A was found to be dependent on MAPK activity, linking elevated c-Myc expression to deregulated signal transduction in colon cancer.
Background
Alterations in the naive T cell subpopulations have been demonstrated in patients with T cell mediated autoimmune disorders, reminiscent of immunological changes found in the elderly during immunosenescence, including the switch from CD45RA + to CD45RO + T cells and decreased thymic function with increased compensatory proliferative mechanisms, partly associated with latent Cytomegalovirus (CMV) infection. The present study was aimed to investigate proportions of lymphocytes, their relation to CMV-seropositivity and the replicative history of CD45RA + expressing T cells in Hashimoto’s thyroiditis (HT, n = 18) and healthy controls (HC, n = 70).
Methods
Proportions of peripheral T cells were investigated by flow cytometry. The replicative history was assessed by T cell receptor excision circles (TRECs) and relative telomere length (RTL). Expression of CD62L was analyzed by immunohistochemistry in thyroid sections. The role of CMV was assessed by serology, ELISPOT assay and in situ hybridization.
Results
Our results demonstrated a significant increase of CD28-negative T cells, associated with CMV-seropositivity in HT patients. HT showed abundant CD45RO + T cells with peripheral loss of CD62L-expressing CD8 + CD45RA + T cells, the latter mainly depending on disease duration. CD62L was expressed in thyroid lymphocyte infiltrations. The diagnosis of HT and within the HT group CMV-seropositivity were the main determinants for the loss of CD28 expression. RTL was not different between HC and HT. HT showed significantly lower TRECs in CD4 + CD45RA + T cells compared to HC.
Conclusions
Patients with HT display a peripheral T cell phenotype reminiscent of findings in elderly persons or other autoimmune disorders. Whether these mechanisms are primary or secondary to the immunological alterations of autoimmune conditions should be investigated in longitudinal studies which may open research on new therapeutic regimes for treatment of HT and associated autoimmune diseases.
Purpose. The aim of the present study was to characterize the cell of the human periosteum using immunohistological and molecular methods. Methods. Phenotypic properties and the distribution of the cells within the different layers were investigated with immunohistochemical staining techniques and RT-PCR, focussing on markers for stromal stem cells, osteoblasts, osteoclasts and immune cells. Results. Immunohistochemical results revealed that all stained cells were located in the cambium layer and that most cells were positive for vimentin. The majority of cells consisted of stromal stem cells and osteoblastic precursor cells. The density increased towards the deeper layers of the cambium. In addition, cells positive for markers of the osteoblast, chondrocyte, and osteoclast lineages were found. Interestingly, there were MHC class II-expressing immune cells suggesting the presence of dendritic cells. Using lineage-specific primer pairs RT-PCR confirmed the immunofluorescence microscopy results, supporting that human periosteum serves as a reservoir of stromal stem cells, as well as cells of the osteoblastic, and the chondroblastic lineage, osteoclasts, and dendritic cells. Conclusion. Our work elucidates the role of periosteum as a source of cells with a high regenerative capacity. Undifferentiated stromal stem cells as well as osteoblastic precursor cells are dominating in the cambium layer. A new outlook is given towards an immune response coming from the periosteum as MHC II positive immune cells were detected.
Introduction
Groin infections resulting in arterial bleeding due to bacterial vessel destruction are a severe challenge in vascular surgery. Patients with them most often present as emergencies and therefore need individualized reconstruction solutions.
Case presentation
Case 1 is a 67-year-old man with infectious bleeding after an autologous reconstruction of the femoral bifurcation with greater saphenous vein due to infection of a bovine pericard patch after thrombendarterectomy. Case 2 is a 35-year-old male drug addict and had severe femoral bleeding and infection after repeated intravenous and intra-arterial substance abuse. Both patients were treated with an autologous obturator bypass of the superficial femoral vein. We review the current literature and highlight our therapeutic concept of this clinical entity.
Conclusions
Treatment should include systemic antibiotic medication, surgical control of the infectious site, revascularization and soft tissue repair. An extra-anatomical obturator bypass with autologous superficial femoral vein should be considered as the safest revascularization procedure in infections caused by highly pathogenic bacteria.
Background: Diabetes is a risk factor for (micro) vascular damage of the brain, too. Therefore cognitive performance after coronary artery bypass grafting may be hypothesized worse in diabetics. To avoid observational errors a reliable tool for testing attentional performance was used. We evaluated whether diabetes mellitus disposes to distinct cognitive dysfunction after coronary artery bypass grafting (CABG). Methods: Three aspects in attentional performance were prospectively tested with three different tests (alertness: composed of un-cued and cued reaction, divided attention, and selective attention) by a computerized tool one day before and seven days after CABG in a highly selected cohort of 30 males, 10 of whom had diabetes. Statistical comparisons were done with analysis of variance for repeated measurements and Fisher´s LSD. Results: Prior to CABG there was no statistically meaningful difference between diabetics and non-diabetics. Postoperatively, diabetic patients performed significantly worse than non-diabetics in tests for un-cued (p=0.01) and cued alertness (p=0.03). Test performance in divided attention was worse after CABG but independent of diabetes status. Selective attention was neither affected by diabetes status nor by CABG itself. Conclusions: Diabetes may have an impact on cognitive performance after CABG. More severe deficits in alertness may point to underlying microvascular disease.
Background: Ascorbic acid demonstrates a cytotoxic effect by generating hydrogen peroxide, a reactive oxygen species (ROS) involved in oxidative cell stress. A panel of eleven human cancer cell lines, glioblastoma and carcinoma, were exposed to serial dilutions of ascorbic acid (5-100 mmol/L). The purpose of this study was to analyse the impact of catalase, an important hydrogen peroxide-detoxifying enzyme, on the resistance of cancer cells to ascorbic acid mediated oxidative stress. Methods: Effective concentration (EC50) values, which indicate the concentration of ascorbic acid that reduced the number of viable cells by 50%, were detected with the crystal violet assay. The level of intracellular catalase protein and enzyme activity was determined. Expression of catalase was silenced by catalase-specific short hairpin RNA (sh-RNA) in BT-20 breast carcinoma cells. Oxidative cell stress induced apoptosis was measured by a caspase luminescent assay. Results: The tested human cancer cell lines demonstrated obvious differences in their resistance to ascorbic acid mediated oxidative cell stress. Forty-five percent of the cell lines had an EC50>20 mmol/L and fifty-five percent had an EC50<20 mmol/L. With an EC50 of 2.6–5.5 mmol/L, glioblastoma cells were the most susceptible cancer cell lines analysed in this study. A correlation between catalase activity and the susceptibility to ascorbic acid was observed. To study the possible protective role of catalase on the resistance of cancer cells to oxidative cell stress, the expression of catalase in the breast carcinoma cell line BT-20, which cells were highly resistant to the exposure to ascorbic acid (EC50: 94,9 mmol/L), was silenced with specific sh-RNA. The effect was that catalase-silenced BT-20 cells (BT-20 KD-CAT) became more susceptible to high concentrations of ascorbic acid (50 and 100 mmol/L). Conclusions: Fifty-five percent of the human cancer cell lines tested were unable to protect themselves against oxidative stress mediated by ascorbic acid induced hydrogen peroxide production. The antioxidative enzyme catalase is important to protect cancer cells against cytotoxic hydrogen peroxide. Silenced catalase expression increased the susceptibility of the formerly resistant cancer cell line BT-20 to oxidative stress.
Purpose: Preclinical experiments on large animals are indispensable for evaluating the effectiveness of diabetes therapies. Miniature swine are well suited for such studies due to their physiological and pathophysiological responses. Methods: We compare two methods for inducing diabetes in Goettingen minipigs (GMP), in five with the beta cell toxin streptozotocin (STZ) and in five other GMP by total pancreatectomy (PE). Glucose homeostasis was assessed with the intravenous glucose-tolerance test (IVGTT) and continual monitoring of interstitial glucose levels. At conclusion of the observation period, the pancreata were examined histologically. Three non-diabetic GMP served as control group. Results: The IVGTT revealed markedly diabetic profiles in both GMP groups. STZ-GMP were found to harbor residual C-peptides and scattered insulin-positive cells in the pancreas. PE-GMP survived the total pancreatectomy only with intensive postoperative care. Conclusions: Although both methods reliably induced diabetes in GMP, the PE-GMP clearly had more health problems and required a greater expenditure of time and resources. The PE-GMP model, however, was better at eliminating endogenous insulin and C-peptide than the STZ-GMP model.
BACKGROUND:
Although the repair of ventral abdominal wall hernias is one of the most commonly performed operations, many aspects of their treatment are still under debate or poorly studied. In addition, there is a lack of good definitions and classifications that make the evaluation of studies and meta-analyses in this field of surgery difficult.
MATERIALS AND METHODS:
Under the auspices of the board of the European Hernia Society and following the previously published classifications on inguinal and on ventral hernias, a working group was formed to create an online platform for registration and outcome measurement of operations for ventral abdominal wall hernias. Development of such a registry involved reaching agreement about clear definitions and classifications on patient variables, surgical procedures and mesh materials used, as well as outcome parameters. The EuraHS working group (European registry for abdominal wall hernias) comprised of a multinational European expert panel with specific interest in abdominal wall hernias. Over five working group meetings, consensus was reached on definitions for the data to be recorded in the registry.
RESULTS:
A set of well-described definitions was made. The previously reported EHS classifications of hernias will be used. Risk factors for recurrences and co-morbidities of patients were listed. A new severity of comorbidity score was defined. Post-operative complications were classified according to existing classifications as described for other fields of surgery. A new 3-dimensional numerical quality-of-life score, EuraHS-QoL score, was defined. An online platform is created based on the definitions and classifications, which can be used by individual surgeons, surgical teams or for multicentre studies. A EuraHS website is constructed with easy access to all the definitions, classifications and results from the database.
CONCLUSION:
An online platform for registration and outcome measurement of abdominal wall hernia repairs with clear definitions and classifications is offered to the surgical community. It is hoped that this registry could lead to better evidence-based guidelines for treatment of abdominal wall hernias based on hernia variables, patient variables, available hernia repair materials and techniques.
Purpose
Once open abdomen therapy has succeeded, the problem of closing the abdominal wall must be addressed. We present a new four-stage procedure involving the application of a two-component mesh and vacuum conditioning for abdominal wall closure of even large defects. The aim is to prevent the development of a giant ventral hernia and the eventual need for the repair of the abdominal wall.
Methods
Nineteen of 62 patients treated by open abdomen over a two-year period could not receive primary abdominal wall closure. To achieve closure in these patients, we applied the following four-stage procedure: stage 1: abdominal damage control and conditioning of the abdominal wall; stage 2: attachment of a tailored two-component mesh of polyglycolic acid (PGA) and large pore polypropylene (PP) in intraperitoneal position (IPOM) plus placement of a vacuum bandage; stage 3: vacuum therapy for 3–4 weeks to allow granulation of the mesh and optimization of dermatotraction; stage 4: final skin suture. During stage 3, eligible patients were weaned from respirator and mobilized.
Results
The abdominal wall gap in the 19 patients ranged in size from 240 cm2 to more than 900 cm2. An average of 3.44 vacuum dressing changes over 19 days were required to achieve 60–100 % granulation of the surface area, so final skin suture could be made. Already in stage 3, 14 patients (73.68 %) could be weaned from respirator an average of 6.78 days after placement of the two-component mesh; 6 patients (31.57 %) could be mobilized on the edge of the bed and/or to a bedside chair after an average of 13 days. No mesh-related hematomas, seromas, or intestinal fistulas were observed.
Conclusion
The four-stage procedure presented here is a viable option for achieving abdominal wall closure in patients treated with open abdomen, enabling us to avoid the development of planned giant ventral hernias. It has few complications and has the special advantage of allowing mobilization of the patients before final skin closure. Long-term course in a large number of patients must still confirm this result.
Purpose
Once open abdomen therapy has succeeded, the problem of closing the abdominal wall must be addressed. We present a new four-stage procedure involving the application of a two-component mesh and vacuum conditioning for abdominal wall closure of even large defects. The aim is to prevent the development of a giant ventral hernia and the eventual need for the repair of the abdominal wall.
Methods
Nineteen of 62 patients treated by open abdomen over a two-year period could not receive primary abdominal wall closure. To achieve closure in these patients, we applied the following four-stage procedure: stage 1: abdominal damage control and conditioning of the abdominal wall; stage 2: attachment of a tailored two-component mesh of polyglycolic acid (PGA) and large pore polypropylene (PP) in intraperitoneal position (IPOM) plus placement of a vacuum bandage; stage 3: vacuum therapy for 3–4 weeks to allow granulation of the mesh and optimization of dermatotraction; stage 4: final skin suture. During stage 3, eligible patients were weaned from respirator and mobilized.
Results
The abdominal wall gap in the 19 patients ranged in size from 240 cm2 to more than 900 cm2. An average of 3.44 vacuum dressing changes over 19 days were required to achieve 60–100 % granulation of the surface area, so final skin suture could be made. Already in stage 3, 14 patients (73.68 %) could be weaned from respirator an average of 6.78 days after placement of the two-component mesh; 6 patients (31.57 %) could be mobilized on the edge of the bed and/or to a bedside chair after an average of 13 days. No mesh-related hematomas, seromas, or intestinal fistulas were observed.
Conclusion
The four-stage procedure presented here is a viable option for achieving abdominal wall closure in patients treated with open abdomen, enabling us to avoid the development of planned giant ventral hernias. It has few complications and has the special advantage of allowing mobilization of the patients before final skin closure. Long-term course in a large number of patients must still confirm this result.
Background
Although the repair of ventral abdominal wall hernias is one of the most commonly performed operations, many aspects of their treatment are still under debate or poorly studied. In addition, there is a lack of good definitions and classifications that make the evaluation of studies and meta-analyses in this field of surgery difficult.
Materials and methods
Under the auspices of the board of the European Hernia Society and following the previously published classifications on inguinal and on ventral hernias, a working group was formed to create an online platform for registration and outcome measurement of operations for ventral abdominal wall hernias. Development of such a registry involved reaching agreement about clear definitions and classifications on patient variables, surgical procedures and mesh materials used, as well as outcome parameters. The EuraHS working group (European registry for abdominal wall hernias) comprised of a multinational European expert panel with specific interest in abdominal wall hernias. Over five working group meetings, consensus was reached on definitions for the data to be recorded in the registry.
Results
A set of well-described definitions was made. The previously reported EHS classifications of hernias will be used. Risk factors for recurrences and co-morbidities of patients were listed. A new severity of comorbidity score was defined. Post-operative complications were classified according to existing classifications as described for other fields of surgery. A new 3-dimensional numerical quality-of-life score, EuraHS-QoL score, was defined. An online platform is created based on the definitions and classifications, which can be used by individual surgeons, surgical teams or for multicentre studies. A EuraHS website is constructed with easy access to all the definitions, classifications and results from the database.
Conclusion
An online platform for registration and outcome measurement of abdominal wall hernia repairs with clear definitions and classifications is offered to the surgical community. It is hoped that this registry could lead to better evidence-based guidelines for treatment of abdominal wall hernias based on hernia variables, patient variables, available hernia repair materials and techniques.
Background: The use of assisted reproductive techniques (ART) for treatment of infertility is increasing rapidly worldwide. However, various health effects have been reported including a higher risk of congenital malformations. Therefore, we assessed the risk of anorectal malformations (ARM) after in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).
Methods: Data of the German Network for Congenital Uro-REctal malformations (CURE-Net) were compared to nationwide data of the German IVF register and the Federal Statistical Office (DESTATIS). Odds ratios (95% confidence intervals) were determined to quantify associations using multivariable logistic regression accounting for potential confounding or interaction by plurality of births.
Results: In total, 295 ARM patients born between 1997 and 2011 in Germany, who were recruited through participating pediatric surgeries from all over Germany and the German self-help organisation SoMA, were included. Controls were all German live-births (n = 10,069,986) born between 1997 and 2010. Overall, 30 cases (10%) and 129,982 controls (1%) were born after IVF or ICSI, which translates to an odds ratio (95% confidence interval) of 8.7 (5.9-12.6) between ART and ARM in bivariate analyses. Separate analyses showed a significantly increased risk for ARM after IVF (OR, 10.9; 95% CI, 6.2-19.0; P < 0.0001) as well as after ICSI (OR, 7.5; 95% CI, 4.6-12.2; P < 0.0001). Furthermore, separate analyses of patients with isolated ARM, ARM with associated anomalies and those with a VATER/VACTERL association showed strong associations with ART (ORs 4.9, 11.9 and 7.9, respectively). After stratification for plurality of birth, the corresponding odds ratios (95% confidence intervals) were 7.7 (4.6-12.7) for singletons and 4.9 (2.4-10.1) for multiple births. Conclusions: There is a strongly increased risk for ARM among children born after ART. Elevations of risk were seen after both IVF and ICSI. Further, separate analyses of patients with isolated ARM, ARM with associated anomalies and those with a VATER/VACTERL association showed increased risks in each group. An increased risk of ARM was also seen among both singletons and multiple births.
The method to induce unilateral cryogenic lesions was first described in 1958 by Klatzo. We describe here an adaptation of this model that allows reliable measurement of lesion volume and vasogenic edema by 2, 3, 5-triphenyltetrazolium chloride-staining and Evans blue extravasation in mice. A copper or aluminium cylinder with a tip diameter of 2.5 mm is cooled with liquid nitrogen and placed on the exposed skull bone over the parietal cortex (coordinates from bregma: 1.5 mm posterior, 1.5 mm lateral). The tip diameter and the contact time between the tip and the parietal skull determine the extent of cryolesion. Due to an early damage of the blood brain barrier, the cryogenic cortical injury is characterized by vasogenic edema, marked brain swelling, and inflammation. The lesion grows during the first 24 hours, a process involving complex interactions between endothelial cells, immune cells, cerebral blood flow, and the intracranial pressure. These contribute substantially to the damage from the initial injury. The major advantage of the cryogenic lesion model is the circumscribed and highly reproducible lesion size and location.
Background:
Single drug use has not achieved satisfactory results in the treatment of prostate cancer, despite application of increasingly widespread targeted therapeutics. In the present study, the combined impact of the mammalian target of rapamycin (mTOR)-inhibitor RAD001, the dual EGFr and VGEFr tyrosine kinase inhibitor AEE788 and the histone deacetylase (HDAC)-inhibitor valproic acid (VPA) on prostate cancer growth and adhesion in vitro was investigated.
Methods:
PC-3, DU-145 and LNCaP cells were treated with RAD001, AEE788 or VPA or with a RAD-AEE-VPA combination. Tumor cell growth, cell cycle progression and cell cycle regulating proteins were then investigated by MTT-assay, flow cytometry and western blotting, respectively. Furthermore, tumor cell adhesion to vascular endothelium or to immobilized extracellular matrix proteins as well as migratory properties of the cells was evaluated, and integrin alpha and beta subtypes were analyzed. Finally, effects of drug treatment on cell signaling pathways were determined.
Results:
All drugs, separately applied, reduced tumor cell adhesion, migration and growth. A much stronger anticancer effect was evoked by the triple drug combination. Particularly, cdk1, 2 and 4 and cyclin B were reduced, whereas p27 was elevated. In addition, simultaneous application of RAD001, AEE788 and VPA altered the membranous, cytoplasmic and gene expression pattern of various integrin alpha and beta subtypes, reduced integrin-linked kinase (ILK) and deactivated focal adhesion kinase (FAK). Signaling analysis revealed that EGFr and the downstream target Akt, as well as p70S6k was distinctly modified in the presence of the drug combination.
Conclusions:
Simultaneous targeting of several key proteins in prostate cancer cells provides an advantage over targeting a single pathway. Since strong anti-tumor properties became evident with respect to cell growth and adhesion dynamics, the triple drug combination might provide progress in the treatment of advanced prostate cancer.
Background: Investigation of the expression of an intestinal stem cell marker in esophageal adenocarcinomas (EAC) with and without Barrett’s Esophagus (BE), with respect to a cancer stem cell (CSC) hypothesis. Materials and methods: Expression of a putative intestinal stem cell marker LgR5 was analyzed in esophageal cancer specimen (n = 70: 41 EAC with BE, 19 EAC without BE, and n = 10 esophageal squamous-cell carcinomas, ESCC) and in the adenocarcinoma cell line OE-33. Ki-67 and Cdx-2 were co-labelled with LgR5 in double staining experiments. Immunhistochemical expression results were confirmed by RT-PCR and correlated with tumor stage and five-year survival rates. Results: LgR5was found expressed in 35 of 41 (85%) EAC with BE and in 16 of 19 (81%) EAC without BE. By contrast, LgR5 was not found to be expressed in ESCC. Quantification of immunolabeling showed 15% LgR5+ cells in EAC with BE, 32% LgR5+ cells in adjacent BE and 13% in EAC without BE. Immunofluorescence double staining experiments with LgR5 and Ki-67 revealed a subpopulation (~5%) of proliferating LgR+/Ki-67+ cells. On mRNAlevel, expression of LgR5 was higher in BE in comparison to EAC (p = 0.0159). High levels of LgR5 expression in BE associated EAC were associated with poorer survival in univariate analysis. Conclusion: The stem cell marker LgR5 is expressed in EAC, irrespective of association with BE, and appears to have negative impact on survival. The subset of proliferating LgR5+ cells (<5%) might resemble rapidly cycling CSCs, which needs to be substantiated in further investigations.
Background
Investigation of the expression of an intestinal stem cell marker in esophageal adenocarcinomas (EAC) with and without Barrett's Esophagus (BE), with respect to a cancer stem cell (CSC) hypothesis.
Materials and methods
Expression of a putative intestinal stem cell marker LgR5 was analyzed in esophageal cancer specimen (n = 70: 41 EAC with BE, 19 EAC without BE, and n = 10 esophageal squamous-cell carcinomas, ESCC) and in the adenocarcinoma cell line OE-33. Ki-67 and Cdx-2 were co-labelled with LgR5 in double staining experiments. Immunhistochemical expression results were confirmed by RT-PCR and correlated with tumor stage and five-year survival rates.
Results
LgR5was found expressed in 35 of 41 (85%) EAC with BE and in 16 of 19 (81%) EAC without BE. By contrast, LgR5 was not found to be expressed in ESCC. Quantification of immunolabeling showed 15% LgR5+ cells in EAC with BE, 32% LgR5+ cells in adjacent BE and 13% in EAC without BE. Immunofluorescence double staining experiments with LgR5 and Ki-67 revealed a subpopulation (~5%) of proliferating LgR+/Ki-67+ cells. On mRNA-level, expression of LgR5 was higher in BE in comparison to EAC (p = 0.0159). High levels of LgR5 expression in BE associated EAC were associated with poorer survival in univariate analysis.
Conclusion
The stem cell marker LgR5 is expressed in EAC, irrespective of association with BE, and appears to have negative impact on survival. The subset of proliferating LgR5+ cells (<5%) might resemble rapidly cycling CSCs, which needs to be substantiated in further investigations.
Background and Objective
This study evaluates whether Computer Tomography is an effective procedure for preoperative staging of patients with Peritoneal Carcinomatosis.
Method
A sample of 37 patients was analyzed with contrast enhanced abdominal Computer Tomography, followed by surgical staging. All Computer Tomography scans were evaluated 3 times by 2 radiologists with one radiologist reviewing 2 times. The efficacy of Computer Tomography was evaluated using the Spearman correlation coefficient. Correlations were analyzed by abdominopelvic region to assess results of the Peritoneal Carcinomatosis Index (PCI) aggregating the 13 regions. Surgical findings were compared to radiological findings.
Results
Results indicate high correlations between the surgical and radiological Peritoneal Carcinomatosis Indices. Analyses of the intra-class correlation between the first and second reading of one radiologist suggest high intra-observer reliability. Correlations by abdominopelvic region show higher values in the upper and middle regions and relatively lower values in the lower regions and the small bowel (correlation coefficients range between 0.418 and 0.726, p < 0.010; sensitivities range between 50% and 96%; and specificities range between 62% and 100%).
Conclusion
Computer Tomography represents an effective procedure in the preoperative staging of patients with PC. However, results by abdominopelvic region show lower correlation, therefore suggest lower efficacy. These results are supported by analyses of sensitivity and accuracy by lesion size. This suggests that Computer Tomography is an effective procedure for pre-operative staging but less for determining a tumor's accurate extent.
Background CD30+ T-cell lymphoproliferations comprise a spectrum of clinically heterogeneous entities, including systemic anaplastic large cell lymphomas (ALK- and ALK+) and primary cutaneous CD30+ T-cell lymphoproliferative disorders. While all these entities are characterized by proliferation of highly atypical, anaplastic CD30+ T cells, the expression of T-cell specific antigens in the tumor cells is not consistently detectable. Design and Methods We evaluated biopsies from 19 patients with primary cutaneous CD30+ lymphoproliferative disorders, 38 with ALK- and 33 with ALK+ systemic anaplastic large cell lymphoma. The biopsies were examined for the expression of T-cell receptoraβ/CD3 complex (CD3γ, δ, ε, ζ), transcription factors regulating T-cell receptor expression (ATF1, ATF2, TCF-1, TCF-1a/LEF-1, Ets1), and molecules of T-cell receptor-associated signaling cascades (Lck, ZAP-70, LAT, bcl-10, Carma1, NFATc1, c-Jun, c-Fos, Syk) using immunohistochemistry. Results In comparison to the pattern in 20 peripheral T-cell lymphomas, not otherwise specified, we detected a highly disturbed expression of the T-cell receptor/CD3 complex, TCF-1, TCF- 1a/LEF-1, Lck, ZAP-70, LAT, NFATc1, c-Jun, c-Fos and Syk in most of the systemic anaplastic large cell lymphomas. In addition, primary cutaneous CD30+ lymphoproliferative disorders showed such a similar expression pattern to that of systemic anaplastic large cell lymphomas, that none of the markers we investigated can reliably distinguish between these CD30+ T-cell lymphoproliferations. Conclusions Severely altered expression of the T-cell receptor/CD3 complex, T-cell receptor-associated transcription factors and signal transduction molecules is a common characteristic of systemic and cutaneous CD30+ lymphoproliferations, although the clinical behavior of these entities is very different. Since peripheral T-cell lymphomas, not otherwise specified retain the full expression program required for functioning T-cell receptor signaling, the differential expression of a subset of these markers might be of diagnostic utility in distinguishing peripheral T-cell lymphomas, not otherwise specified from the entire group of CD30+ lymphoproliferations.
Anti-EGFR targeted therapy is a potent strategy in the treatment of metastatic colorectal cancer (mCRC) but activating mutations in the KRAS gene are associated with poor response to this treatment. Therefore, KRAS mutation analysis is employed in the selection of patients for EGFR-targeted therapy and various studies have shown a high concordance between the mutation status in primary CRC and corresponding metastases. However, although development of therapy related resistance occurs also in the context of novel drugs such as tyrosine kinase-inhibitors the effect of the anti-EGFR treatment on the KRAS/BRAF mutation status itself in recurrent mCRC has not yet been clarified. Therefore, we analyzed 21mCRCs before/after anti-EGFR therapy and found a pre-/posttherapeutic concordance of the KRAS/BRAF mutation status in 20 of the 21 cases examined. In the one discordant case, further analyses revealed that a tumor mosaicism or multiple primary tumors were present, indicating that anti-EGFR therapy has no influence on KRAS/BRAF mutation status in mCRC. Moreover, as the preselection of patients with a KRASwt genotype for anti-EGFR therapy has become a standard procedure, sample sets such ours might be the basis for future studies addressing the identification of potential anti-EGFR therapy induced genetic alterations apart from KRAS/BRAF mutations.
Background: Esophageal adenocarcinomas (EACs) arise due to gastroesophageal reflux, with Barrett’s esophagus (BE) regarded as precancerous lesion. Matrix metalloproteinases (MMPs) might play a role during the multistep carcinogenetic process. Methods: Expression of MMP-1 and -13 was analyzed in esophageal cancer (n = 41 EAC with BE, n = 19 EAC without BE, and n = 10 esophageal squamous-cell carcinomas, ESCC), furthermore in BE without intraepithelial neoplasia (IN) (n = 18), and the cell line OE-33. MMP-1 was co-labelled with Ki-67 (proliferation), Cdx-2 (marker for intestinal metaplasia, BE) and analyzed on mRNA level. MMP-1 staining results were correlated with clinicopatholocical parameters. Results: On protein level, MMP-1 expression was found in 39 of 41 (95%) EAC with BE, in 19 of 19 (100%) EAC without BE, in 6 of 10 (60%) ESCC, and in 10 of 18 (56%) BE without IN. No expression of MMP-13 was found in these specimens. Quantification showed 48% MMP-1 positive cells in EAC with BE, compared to 35% in adjacent BE (p < 0.05), 44% in EAC without BE, 32% in ESCC, and 4% in BE without IN. Immunofluorescence double staining experiments revealed increased MMP-1 expressing in proliferating cells (MMP-1+/Ki-67+) (r = 0.943 for BE and r = 0.811 for EAC). On mRNA-level, expression of MMP-1 was significantly higher in EAC compared to BE (p = 0.01) and confirmed immunohistochemical staining results. High MMP-1 levels were associated with lymph node metastases but not with poorer survival (p = 0.307). Conclusions: Our findings suggest that MMP-1 plays a role as preinvasive factor in BE-associated EAC. Expression of MMP-1 in proliferating BE and EAC cells suggest malignant proliferation following the clonal expansion model.
Rhabdomyosarcoma (RMS) is the most common malignant soft tissue tumor in children and is highly resistant to all forms of treatment currently available once metastasis or relapse has commenced. As it has recently been determined that the acetylcholine receptor (AChR) γ-subunit, which defines the fetal AChR (fAChR) isoform, is almost exclusively expressed in RMS post partum, we recombinantly fused a single chain variable fragment (scFv) derived from a fully human anti-fAChR Fab-fragment to Pseudomonas exotoxin A to generate an anti-fAChR immunotoxin (scFv35-ETA).While scFv35-ETA had no damaging effect on fAChR-negative control cell lines, it killed human embryonic and alveolar RMS cell lines in vitro and delayed RMS development in a murine transplantation model. These results indicate that scFv35-ETA may be a valuable new therapeutic tool as well as a relevant step towards the development of a fully human immunotoxin directed against RMS. Moreover, as approximately 20% of metastatic malignant melanomas (MMs) display rhabdoid features including the expression of fAChR, the immunotoxin we developed may also prove to be of significant use in the treatment of these more common and most often fatal neoplasms.
Evaluation of immunological escape mechanisms in a mouse model of colorectal liver metastases
(2010)
Background: The local and systemic activation and regulation of the immune system by malignant cells during carcinogenesis is highly complex with involvement of the innate and acquired immune system. Despite the fact that malignant cells do have antigenic properties their immunogenic effects are minor suggesting tumor induced mechanisms to circumvent cancer immunosurveillance. The aim of this study is the analysis of tumor immune escape mechanisms in a colorectal liver metastases mouse model at different points in time during tumor growth. Methods: CT26.WT murine colon carcinoma cells were injected intraportally in Balb/c mice after median laparotomy using a standardized injection technique. Metastatic tumor growth in the liver was examined by standard histological procedures at defined points in time during metastatic growth. Liver tissue with metastases was additionally analyzed for cytokines, T cell markers and Fas/Fas-L expression using immunohistochemistry, immunofluorescence and RT-PCR. Comparisons were performed by analysis of variance or paired and unpaired t test when appropriate. Results: Intraportal injection of colon carcinoma cells resulted in a gradual and time dependent metastatic growth. T cells of regulatory phenotype (CD4+CD25+Foxp3+) which might play a role in protumoral immune response were found to infiltrate peritumoral tissue increasingly during carcinogenesis. Expression of cytokines IL-10, TGF-b and TNF-a were increased during tumor growth whereas IFN-g showed a decrease of the expression from day 10 on following an initial increase. Moreover, liver metastases of murine colon carcinoma show an up-regulation of FAS-L on tumor cell surface with a decreased expression of FAS from day 10 on. CD8+ T cells express FAS and show an increased rate of apoptosis at perimetastatic location. Conclusions: This study describes cellular and macromolecular changes contributing to immunological escape mechanisms during metastatic growth in a colorectal liver metastases mouse model simulating the situation in human cancer.
Background: We evaluate the long-term survival of patients with peritoneal carcinomatosis (PC) treated with systemic chemotherapy regimens, and the impact of the of the retrospective peritoneal disease severity score (PSDSS) on outcomes. Methods: One hundred sixty-seven consecutive patients treated with PC from colorectal cancer between years 1987-2006 were identified from a prospective institutional database. These patients either received no chemotherapy, 5-FU/Leucovorin or Oxaliplatin/Irinotecan-based chemotherapy. Stratification was made according to the retrospective PSDSS that classifies PC patients based on clinically relevant factors. Survival analysis was performed using the Kaplan-Meier method and comparison with the log-rank test. Results: Median survival was 5 months (95% CI, 3-7 months) for patients who had no chemotherapy, 11 months (95% CI, 6-9 months) for patients treated with 5 FU/LV, and 12 months (95% CI, 4-20 months) for patients treated with Oxaliplatin/Irinotecan-based chemotherapy. Survival differed between patients treated with chemotherapy compared to those patients who did not receive chemotherapy (p = 0.026). PSDSS staging was identified as an independent predictor for survival on multivariate analysis [RR 2.8 (95%CI 1.5-5.4); p < 0.001]. Conclusion: A trend towards improved outcomes is demonstrated from treatment of patients with PC from colorectal cancer using modern systemic chemotherapy. The PSDSS appears to be a useful tool in patient selection and prognostication in PC of colorectal origin.
Background: Adrenocortical carcinoma (ACC) is a rare tumor with a poor prognosis. Often, the physicians who first treat patients with ACC have no prior experience with the disease. The aim of our study was to evaluate the quality of medical care for patients with ACC in Germany.
Methods: Data from the German ACC registry were analyzed with regard to the patients’ preoperative diagnostic evaluation, histopathological reporting, and clinical followup. The findings were compared with the recommendations of the European Network for the Study of Adrenal Tumors (ENSAT).
Results: Data were analyzed from 387 patients who had been given an initial diagnosis of ACC in the years 1998 to 2009. 21% of them underwent no hormonal evaluation before surgery, and 59% underwent an inadequate hormonal evaluation. This exposed the patients to unnecessary perioperative risks and impaired their follow-up. 48% did not undergo CT scanning of the chest, even though the lungs are the most frequent site of metastases of ACC. For 13% of the patients, the diagnosis of ACC was later revised by a reference pathologist. For 11% of the patients, the histopathology report contained no information about resection status, even though this is an important determinant of further treatment and prognosis. Optimal management requires re-staging at three-month intervals, yet some patients underwent re-staging only after a longer delay, or not at all.
Conclusion: We have identified significant deficits in the care of patients with ACC in Germany. We suspect that the situation is similar for other rare diseases. The prerequisite to better care is close and early cooperation of the treating physicians with specialized centers.
Solid organ transplantation is an established therapeutic approach in modern medicine to extend and to improve the life of patients in the final stages of organ failure. Transplantation between genetically non-identical individuals leads to the activation of the transplant recipient's immune system. This alloimmune response is a consequence of the recognition of foreign MHC molecules by alloreactive host T cells. To prevent their activation and the subsequently induced activation of further cell subsets (e.g. B cells, cytotoxic T cells, macrophages)immunosuppressive drugs are absolutely necessary in the clinic. However,permanent immunosuppression leads to severe side effects such as nephrotoxicity, diabetes and hyperlipidaemia, and a reduced immunity to infections and malignant diseases. At the moment, there is no real alternative to immunosuppression. The purpose of this study was to analyse the importance of rat dendritic cells with immune inhibitory properties to prevent the immune activation after experimental transplantation. The rat is one of the most important animal models for experimental organ transplantation in a clinic-relevant procedure. In order to modulate the immune response after transplantation in an antigenspecific manner, the strategy should include the alloantigens. These antigens have to be presented by immature dendritic cells in the absence of costimulatory signals in order to turn alloreactive T cells into anergic or regulatory T cells instead of effector T cells. For a certain rat model of allograft rejection,the immunodominant peptide P1 was identified as an important alloantigen which accelerates graft rejection. Such a model offers an attractive and practical approach to analyse the potential of host tolerogeneic dendritic cells pulsed with P1 to suppress the allograft-induced immune response in an antigen-specific manner without the need of chronic immunosuppression. A homogenous population of rat immature dendritic cells was generated from bone marrow precursors cultured with GM-CSF and IL-4 (= IL-4 DCs) or GM65 CSF and IL-10 (= IL-10 DCs). These cells with an identical immature phenotype showed no or a very low surface expression of costimulatory molecules like CD80 and CD86 and a 10-fold reduced expression of MHC class II molecules in comparison to mature splenic DCs. No obvious difference was observed between the phenotype of the IL-4 DCs and the IL-10 DCs. Neither IL-4 DCs nor IL-10 DCs were able to activate naïve T cells or to restimulate antigen-specific T cells. This strong inhibitory effect, mediated within 24 hours, was dependent on the number of immature dendritic cells added to the proliferation assay. Antigen-specific T cells pre-incubated with IL-4 DCs and IL-10 DCs, respectively, were not able to proliferate in the presence of P1-pulsed mature DCs. This anergic state was reversible with the addition of exogenous IL-2. T cells incubated with IL-4 DCs (= IL-4 DC-Ts) were able to inhibit the T cell proliferation in a cell number dependent manner. In contrast, antigen-specific T cells pre-incubated with P1-pulsed IL-10 DCs (= IL-10 DC-Ts)showed no effect on the proliferation assay. This was the unique difference between IL-4 DCs and IL-10 DCs found in the present study. Immature DCs influenced also the immune response after transplantation. Different numbers of P1-loaded immature IL-4 DCs and IL-10 DCs were transferred intravenously into Lewis rats one day before transplantation. The best results were obtained with 30 million P1-pulsed immature DCs which prolonged the survival time to a median of 11.2 ± 1.6 days. In addition, the antigen specificity of this effect was demonstrated with a third-party graft from Brown Norway donors. These findings suggest that an antigen-specific modulation of the immune response is possible using immature dendritic cells loaded with the allogeneic antigens. Even more, the protocols described in the present study show that the immune system can be, at least temporarily, controlled after transplantation without the use of immunosuppressive drugs.
Transplantation is now firmly established as a therapeutic approach to extend and improve the life of patients in the final stages of organ failure. It has been demonstrated that transplantation between genetically non-identical individuals leads to the activation of the recipient’s alloimmune response as a major determinant of transplant outcome. T cell recognition of foreign MHC molecules plays a key role in initiating and sustaining allograft rejection. To prevent the risk of rejection, patients are given immunosuppressive drugs, which are non-specific and have major side-effects (infections, malignancies). It has been shown that the alloreactive T cells specifically recognize donor MHC-derived peptides. This implies that it may be possible to develop antigen-specific strategies in order to modulate the alloimmune response by peptide analogues and specifically altered peptide ligands. The purpose of this study was to explore the potential of “recipient-adapted” analogues from the dominant MHC class I peptide to modulate the alloimmune response. Beside the significant role of donor dominant determinants in the rejection process, we tested seven 13-to-24-mer peptides from the Wistar-Furth MHC class I molecule (WF, RT1.Au) for their possible immunogenicity in a fully MHC-mismatched WF to Lewis (LEW, RT1l) rat strain combination. Secondly, the immunodominant allopeptide was selected to generate analogues in order to investigate their modulatory capacity. All peptides were tested in vitro in a standard proliferation assay and in vivo using a heterotopic heart transplantation model. Our findings show that five peptides (P1-P5) were able to induce specific T cell proliferation in LEW responders. Furthermore, we found a hierarchical distribution of the determinants: peptide P1 as a good candidate for the immunodominant determinant, while P2, P3, P4, and P5 as subdominant epitopes and the other two peptides, P6 and P7, as non-immunogenic determinants of WF MHC class I molecule. Furthermore, the dominance of P1 was confirmed by the strong proliferation induced after immunization with a mixture of peptides in the presence of P1. This hierarchical distribution of the proliferative response correlated with the cytokine production. Peptide P1, comprising only 3 allogeneic amino acids (L5, L9, and T10) induced the strongest T cell proliferation and produced high levels of cytokines, especially IL-2 and IFN-g. In addition, the immunodominance of peptide P1 was confirmed by the significant reduction in the allograft survival time in comparison to the non-immunized control animals. Since the TCR Vß repertoire of rejected graft-infiltrating cells in rejected allografts was similar to the profile observed after in vitro restimulation of P1-primed T cells, we concluded that peptide P1 is able to activate the alloreactive T cell population. Our results demonstrate the particular role of the dominant peptide P1 (residues 1-19) in the allograft rejection in WF to LEW rat strain combination. In the second set of experiments, we investigated the fine specificity of the dominant peptide P1-activated T cells using peptide analogues from P1. The “recipient-adapted” analogues were designed by changing the allogeneic RT1.Au amino acids (L5, L9, T10) one-by-one with the correspondent syngeneic RT1.Al amino acids (M5, D9, I10) in the sequence of peptide P1. The six peptide analogues (A1.1-A1.6) consisting of either one or two allogeneic amino acids were able to induce a specific T cell proliferative response and cytokine production. Analogue A1.5 with only one allogeneic amino acid (L5) was of particular interest because it induced a low T cell proliferation and high cytokine levels, especially IL-4 and IL-10. In addition, immunization with A1.5 did not influence the allograft survival time in comparison to the non-immunized LEW recipients. A1.5 was the only analogue able to down-regulate the proliferation of P1-primed T cells. Our results reveal that A1.5 is an MHC competitor as confirmed by the in vitro MHC competition assay and the inhibition of the negative effect of P1 on the allograft survival time when recipients were immunized with a mixture of P1 and A1.5. These findings suggest that it is possible to design peptide analogues, such as A1.5, which do not stimulate the dominant peptide P1-specific T cell population and even more, are able to block its presentation in the MHC molecule. In all, the results indicate that the specific suppression of indirect allorecognition can be achieved by using peptide analogues of the dominant allopeptide.
During the past few years, interest in xenotransplantation of porcine islets of Langerhans for the future therapy of type I diabetes has Increased markedly. Therefore, we established a semiautomated digestion method for isolating islets from the porcine pancreas. However, although the isolation technique was standardized and collagenase of controlled quality was used, we were unable to attain high islet yields with a satisfactory degree of reproducibility. One hypothesis was that varying degrees of interference by donor pancreatic enzymes were responsible for this failure. The aim of this stUdy was to examine the kinetics of four types of enzymatic activity during the isolation procedure, as well as their effects on islet yield: collagenase, trypsin, neutral protease, and clostripaln. Our results indicate that while exogenous collagenase activity decreases slightly during the isolation procedure, the activity of the pancreas enzymes neutral protease and trypsin increases. In some cases, trypsin activity increases very strongly. A strong increase in trypsin activity correlates with poor islet yield, whereas low trypsin activity always correlates with high islet yield. Addition of the protease inhibitor Pefabloc to the isolation medium results in low trypsin activity and reproducible high islet yields.
Abstract: For isolating islets from the porcine pancreas, we established a semiautomated digestion method. Although the isolation technique was standardized and collagenase of controlled quality was used, until now the reproducibility of high islet yields was unsatisfactory. Our hypothesis was that pancreatic trypsin was responsible for this failure. The aim of this study was to investigate the effect of endogenous trypsin on islet yield. Our results demonstrate that a high trypsin level correlates with poor islet yield, whereas low trypsin activity always correlates with high islet yield. Specific inhibition of trypsin results in low trypsin activity and reproducible, high islet yields.
Isolation of Islets of Langerhans: Improvement of the Isolation Technique Using the Pig Model.
(1994)
During the last view years, interest in pancreatic islet transplantation for the cure of type I diabetes has increased markedly. A serious barrier to clinical islet transplantation is the isolation of a sufficient mass of viable and functional islets. We used a porcine islet isolation model to examine various parameters of the isolation procedure and to improve isolation technique.
Since systematic hematological studies on blood and bone marrow changes after treatment with 15-Deoxyspergualin (DOS) are lacking, a quantitative assessment was performed fourteen or twenty eight days after intraperitoneal application of DOS to rats. Further observations done 7 and 14 days after discontinuation of DOS administration allowed analysis of banc marrow regeneration. DOS induced lymphocytopenia, granUlocytopenia and anemia with a decrease of bone marrow cellularity due to suppression of cell maturation. The effect was dose-dependent and bone marrow as well as blood changes were observed in animals treated with doses from 0.5 to 10.0 mg/kg DOS. Within 14 days after termination of the treatment, rapid recovery with normalization of all hematological parameters was observed. In the light of our data, these hematological side effects may not be a major disadvantage, if DOS is used in doses below 2.5 mg/kg, and for a course of therapy which is limited to 7 to 14 days.
To decrease immunogenicity of the rat kidney, grafts were perfused with an anti-MHC class li monoclonal antibody (mAb ). How effectively this procedure blocked dass li-positive cells, which were mainly dendritic in appearance, was checked by immunostaining renal sections after perfusion and comparing them with in vitro stained sections. Optimum conditions were applied for graft pretreatment before transplantation. This procedure prolonged graft survival, though not satisfactorily from the biological point ofview (9.6 ± 0.8 versus 7.7 ± 0.5 days in the control group; P < 0.02). The dendritic cells were not killed but blocked. Several hours after transplantation, the mAb dissociated from these dass li-positive cells. It was also shown that donor cells migrate into the recipient's spieen early after transplantation. The number of these cells was smaller when the transplanted organ was perfused with the mAb. Further studies are suggested to deplete the graft of donor dendritic cells more adequately. They should also combine graft perfusion with antidass II mAb and recipient immunosuppression at reduced doses.
No abstract available.