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Introduction: The German PID-NET registry was founded in 2009, serving as the first national registry of patients with primary immunodeficiencies (PID) in Germany. It is part of the European Society for Immunodeficiencies (ESID) registry. The primary purpose of the registry is to gather data on the epidemiology, diagnostic delay, diagnosis, and treatment of PIDs.
Methods: Clinical and laboratory data was collected from 2,453 patients from 36 German PID centres in an online registry. Data was analysed with the software Stata® and Excel.
Results: The minimum prevalence of PID in Germany is 2.72 per 100,000 inhabitants. Among patients aged 1-25, there was a clear predominance of males. The median age of living patients ranged between 7 and 40 years, depending on the respective PID. Predominantly antibody disorders were the most prevalent group with 57% of all 2,453 PID patients (including 728 CVID patients). A gene defect was identified in 36% of patients. Familial cases were observed in 21% of patients. The age of onset for presenting symptoms ranged from birth to late adulthood (range 0-88 years). Presenting symptoms comprised infections (74%) and immune dysregulation (22%). Ninety-three patients were diagnosed without prior clinical symptoms. Regarding the general and clinical diagnostic delay, no PID had undergone a slight decrease within the last decade. However, both, SCID and hyper IgE-syndrome showed a substantial improvement in shortening the time between onset of symptoms and genetic diagnosis. Regarding treatment, 49% of all patients received immunoglobulin G (IgG) substitution (70%-subcutaneous; 29%-intravenous; 1%-unknown). Three-hundred patients underwent at least one hematopoietic stem cell transplantation (HSCT). Five patients had gene therapy.
Conclusion: The German PID-NET registry is a precious tool for physicians, researchers, the pharmaceutical industry, politicians, and ultimately the patients, for whom the outcomes will eventually lead to a more timely diagnosis and better treatment.
Background
Colorectal cancer incidence increases with patient age. The aim of this study was to assess, at the nationwide level, in-hospital mortality, and failure to rescue in geriatric patients (≥ 80 years old) with colorectal cancer arising from postoperative complications.
Methods
All patients receiving surgery for colorectal cancer in Germany between 2012 and 2018 were identified in a nationwide database. Association between age and in-hospital mortality following surgery and failure to rescue, defined as death after complication, were determined in univariate and multivariate analyses.
Results
Three lakh twenty-eight thousands two hundred and ninety patients with colorectal cancer were included of whom 77,287 were 80 years or older. With increasing age, a significant relative increase in right hemicolectomy was observed. In general, these patients had more comorbid conditions and higher frailty. In-hospital mortality following colorectal cancer surgery was 4.9% but geriatric patients displayed a significantly higher postoperative in-hospital mortality of 10.6%. The overall postoperative complication rate as well as failure to rescue increased with age. In contrast, surgical site infection (SSI) and anastomotic leakage (AL) did not increase in geriatric patients, whereas the associated mortality increased disproportionately (13.3% for SSI and 29.9% mortality for patients with AI, both p < 0.001). Logistic regression analysis adjusting for confounders showed that geriatric patients had almost five-times higher odds for death after surgery than the baseline age group below 60 (OR 4.86; 95%CI [4.45–5.53], p < 0.001).
Conclusion
Geriatric patients have higher mortality after colorectal cancer surgery. This may be partly due to higher frailty and disproportionately higher rates of failure to rescue arising from postoperative complications.
This evidence‐based clinical guideline provides consensus‐recommendations for the treatment and care of patients with primary antibody deficiencies (PADs). The guideline group comprised 20 clinical and scientific expert associations of the German, Swiss, and Austrian healthcare system and representatives of patients. Recommendations were based on results of a systematic literature search, data extraction, and evaluation of methodology and study quality in combination with the clinical expertise of the respective representatives. Consensus‐based recommendations were determined via nominal group technique. PADs are the largest clinically relevant group of primary immunodeficiencies. Most patients with PADs present with increased susceptibility to infections, however immune dysregulation, autoimmunity, and cancer affect a significant number of patients and may precede infections. This guideline therefore covers interdisciplinary clinical and therapeutic aspects of infectious (e.g., antibiotic prophylaxis, management of bronchiectasis) and non‐infectious manifestations (e.g., management of granulomatous disease, immune cytopenia). PADs are grouped into disease entities with definitive, probable, possible, or unlikely benefit of IgG‐replacement therapy. Summary and consensus‐recommendations are provided for treatment indication, dosing, routes of administration, and adverse events of IgG‐replacement therapy. Special aspects of concomitant impaired T‐cell function are highlighted as well as clinical data on selected monogenetic inborn errors of immunity formerly classified into PADs (APDS, CTLA‐4‐, and LRBA‐deficiency).
In this thesis, the Josephson effect in mercury telluride based superconducting quantum point contacts (SQPCs) is studied. Implementing such confined structures into topological superconductors has been proposed as a means to detect and braid Majorana fermions. For the successful realization of such experiments though, coherent transport across the constriction is essential. By demonstrating the Josephson effect in a confined topological system, the presented experiments lay the foundation for future quantum devices that can be used for quantum computation. In addition, the experiments also provide valuable insights into the behavior of the Josephson effect in the low-channel limit (N<20). Due to the confinement of the weak link, we can also study the Josephson effect in a topological insulator, where the edge modes interact.
In conclusion, this thesis discusses the fabrication of, and low-temperature measurements on mercury telluride quantum point contacts embedded within Josephson junctions. We find that the merging of the currently used fabrication methods for mercury telluride quantum point contacts and Josephson junctions does not yield a good enough device quality to resolve subbands of the quantum point contact as quantization effects in the transport properties. As we attribute this to the long dry etching time that is necessary for a top-contact, the fabrication process was adapted to reduce the defect density at the superconductor-semiconductor interface. Employing a technique that involves side contacting the mercury telluride quantum well and reducing the size of the mercury telluride mesa to sub-micrometer dimensions yields a quantized supercurrent across the junction. The observed supercurrent per mode is in good agreement with theoretical predictions for ballistic, one-dimensional modes that are longer than the Josephson penetration depth. Moreover, we find that oscillatory features superimpose the plateaus of the supercurrent and the conductance. The strength of these oscillatory features are sample-dependent and complicate the identification of plateaus. We suggest that the oscillatory features originate mainly from local defects and the short gate electrode. Additionally, resonances are promoted within the weak link if the transparency of the superconductor-HgTe interface differs from one.
Furthermore, the research explores the regimes of the quantum spin Hall effect and the 0.5 anomaly. Notably, a small yet finite supercurrent is detected in the QSH regime. In samples fabricated from thick mercury telluride quantum wells, the supercurrent appears to vanish when the quantum point contact is tuned into the regime of the 0.5 anomaly. For samples fabricated from thin mercury telluride quantum wells, the conductance as well as the supercurrent vanish for strong depopulation. In these samples though, the supercurrent remains detectable even for conductance values significantly below 2 e²/h.
Numerical calculation reproduce the transport behavior of the superconducting quantum point contacts.
Additionally, the topological nature of the weak link is thoroughly investigated using the supercurrent diffraction pattern and the absorption of radio frequency photons. The diffraction pattern reveals a gate independent, monotonous decay of $I_\text{sw}(B)$, which is associated with the quantum interference of Andreev bound states funneled through the quantum point contact. Interestingly, the current distribution in the weak link appears unaffected as the quantum point contact is depleted. In the RF measurements, indications of a 4π periodic supercurrent are observed as a suppression of odd Shapiro steps. The ratio of the 4π periodic current to the 2π periodic current appears to decrease for smaller supercurrents, as odd Shapiro steps are exclusively suppressed for large supercurrents. Additionally, considering the observation that the supercurrent is small when the bulk modes in the quantum point contact are fully depleted, we suggest that the re-emerging of odd Shapiro steps is a consequence of the group velocity of the edge modes being significantly suppressed when the bulk modes are absent. Consequently, the topological nature of the superconducting quantum point contact is only noticeable in the transport properties when bulk modes are transmitted through the superconducting quantum point contact.
The shown experiments are the first demonstration of mercury telluride superconducting quantum point contacts that exhibit signatures of quantization effects in the conductance as well as the supercurrent. Moreover, the experiments suggest that the regime of interacting topological edge channels is also accessible in mercury telluride superconducting quantum point contacts. This is potentially relevant for the realization of Majorana fermions and their application in the field of quantum computation.