@article{UeceylerKewenigKafkeetal.2014,
  author    = {{\"U}{\c{c}}eyler, Nurcan and Kewenig, Susanne and Kafke, Waldemar and Kittel-Schneider, Sarah and Sommer, Claudia},
  title     = {Skin cytokine expression in patients with fibromyalgia syndrome is not different from controls},
  doi       = {10.1186/s12883-014-0185-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-110624},
  year      = {2014},
  abstract  = {Background Fibromyalgia syndrome (FMS) is a chronic pain syndrome of unknown etiology. There is increasing evidence for small nerve fiber impairment in a subgroup of patients with FMS. We investigated whether skin cytokine and delta opioid receptor (DOR) gene expression in FMS patients differs from controls as one potential contributor to small nerve fiber sensitization. Methods We investigated skin punch biopsies of 25 FMS patients, ten patients with monopolar depression but no pain, and 35 healthy controls. Biopsies were obtained from the lateral upper thigh and lower calf. Gene expression of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF), interleukin (IL)-6, and IL-8 and of the anti-inflammatory cytokine IL-10 was analyzed using quantitative real-time PCR and normalizing data to 18sRNA as housekeeping gene. Additionally, we assessed DOR gene expression. Results All cytokines and DOR were detectable in skin samples of FMS patients, patients with depression, and healthy controls without intergroup difference. Also, gene expression was not different in skin of the upper and lower leg within and between the groups and in FMS patient subgroups. Conclusions Skin cytokine and DOR gene expression does not differ between patients with FMS and controls. Our results do not support a role of the investigated cytokines in sensitization of peripheral nerve fibers as a potential mechanism of small fiber pathology in FMS.},
  language  = {en}
}
@article{UeceylerKewenigKittelSchneideretal.2015,
  author    = {{\"U}{\c{c}}eyler, Nurcan and Kewenig, Susanne and Kittel-Schneider, Sarah and Fallgatter, Andreas J. and Sommer, Claudia},
  title     = {Increased cortical activation upon painful stimulation in fibromyalgia syndrome},
  series = {BMC Neurology},
  volume    = {15},
  journal   = {BMC Neurology},
  number    = {210},
  doi       = {10.1186/s12883-015-0472-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125230},
  year      = {2015},
  abstract  = {Background Fibromyalgia syndrome (FMS) is a chronic condition characterized by widespread pain and associated symptoms. We investigated cerebral activation in FMS patients by functional near-infrared spectroscopy (fNIRS). Methods Two stimulation paradigms were applied: a) painful pressure stimulation at the dorsal forearm; b) verbal fluency test (VFT). We prospectively recruited 25 FMS patients, ten patients with unipolar major depression (MD) without pain, and 35 healthy controls. All patients underwent neurological examination and all subjects were investigated with questionnaires (pain, depression, FMS, empathy). Results FMS patients had lower pressure pain thresholds than patients with MD and controls (p < 0.001) and reported higher pain intensity (p < 0.001). Upon unilateral pressure pain stimulation fNIRS recordings revealed increased bilateral cortical activation in FMS patients compared to controls (p < 0.05). FMS patients also displayed a stronger contralateral activity over the dorsolateral prefrontal cortex in direct comparison to patients with MD (p < 0.05). While all three groups performed equally well in the VFT, a frontal deficit in cortical activation was only found in patients with depression (p < 0.05). Performance and cortical activation correlated negatively in FMS patients (p < 0.05) and positively in patients with MD (p < 0.05). Conclusion Our data give further evidence for altered central nervous processing in patients with FMS and the distinction between FMS and MD.},
  language  = {en}
}
@article{UeceylerSchliesserEvdokimovetal.2022,
  author    = {{\"U}{\c{c}}eyler, Nurcan and Schließer, Mira and Evdokimov, Dimitar and Radziwon, Jakub and Feulner, Betty and Unterecker, Stefan and Rimmele, Florian and Walter, Uwe},
  title     = {Reduced midbrain raphe echogenicity in patients with fibromyalgia syndrome},
  series = {PloS One},
  volume    = {17},
  journal   = {PloS One},
  number    = {11},
  doi       = {10.1371/journal.pone.0277316},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300639},
  year      = {2022},
  abstract  = {Objectives The pathogenesis of fibromyalgia syndrome (FMS) is unclear. Transcranial ultrasonography revealed anechoic alteration of midbrain raphe in depression and anxiety disorders, suggesting affection of the central serotonergic system. Here, we assessed midbrain raphe echogenicity in FMS. Methods Sixty-six patients underwent transcranial sonography, of whom 53 were patients with FMS (27 women, 26 men), 13 patients with major depression and physical pain (all women), and 14 healthy controls (11 women, 3 men). Raphe echogenicity was graded visually as normal or hypoechogenic, and quantified by digitized image analysis, each by investigators blinded to the clinical diagnosis. Results Quantitative midbrain raphe echogenicity was lower in patients with FMS compared to healthy controls (p<0.05), but not different from that of patients with depression and accompanying physical pain. Pain and FMS symptom burden did not correlate with midbrain raphe echogenicity as well as the presence and severity of depressive symptoms. Conclusion We found reduced echogenicity of the midbrain raphe area in patients with FMS and in patients with depression and physical pain, independent of the presence or severity of pain, FMS, and depressive symptoms. Further exploration of this sonographic finding is necessary before this objective technique may enter diagnostic algorithms in FMS and depression.},
  language  = {en}
}
@article{UeceylerSchroeterKafkeetal.2016,
  author    = {{\"U}{\c{c}}eyler, Nurcan and Schr{\"o}ter, Nils and Kafke, Waldemar and Kramer, Daniela and Wanner, Christoph and Weidemann, Frank and Sommer, Claudia},
  title     = {Skin Globotriaosylceramide 3 Load Is Increased in Men with Advanced Fabry Disease},
  series = {PLoS ONE},
  volume    = {11},
  journal   = {PLoS ONE},
  number    = {11},
  doi       = {10.1371/journal.pone.0166484},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-178856},
  year      = {2016},
  abstract  = {Background The X-chromosomally linked life-limiting Fabry disease (FD) is associated with deposits of the sphingolipid globotriaosylceramide 3 (Gb3) in various tissues. Skin is easily accessible and may be used as an additional diagnostic and follow-up medium. Our aims were to visualize skin Gb3 deposits in FD patients applying immunofluorescence and to determine if cutaneous Gb3 load correlates with disease severity. Methods At our Fabry Center for Interdisciplinary Therapy we enrolled 84 patients with FD and 27 healthy controls. All subjects underwent 5-mm skin punch biopsy at the lateral lower leg and the back. Skin samples were processed for immunohistochemistry using antibodies against CD77 (i.e. Gb3). Cutaneous Gb3 deposition was quantified in a blinded manner and correlated to clinical data. Results We found that Gb3 load was higher in distal skin of male FD patients compared to healthy controls (p<0.05). Men (p<0.01) and women (p<0.05) with a classic FD phenotype had higher distal skin Gb3 load than healthy controls. Men with advanced disease as reflected by impaired renal function, and men and women with small fiber neuropathy had more Gb3 deposits in distal skin samples than males with normal renal function (p<0.05) and without small fiber neuropathy. Gb3 deposits were not different between patients with and without enzyme replacement therapy. Conclusions Immunofluorescence on minimally invasive skin punch biopsies may be useful as a tool for assessment and follow-up in FD patients.},
  language  = {en}
}
@article{UeceylerSommer2014,
  author    = {{\"U}{\c{c}}eyler, Nurcan and Sommer, Claudia},
  title     = {High-Dose Capsaicin for the Treatment of Neuropathic Pain: What We Know and What We Need to Know},
  series = {Pain and Therapy},
  volume    = {3},
  journal   = {Pain and Therapy},
  number    = {2},
  issn      = {2193-651X},
  doi       = {10.1007/s40122-014-0027-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120669},
  pages     = {73-84},
  year      = {2014},
  abstract  = {Neuropathic pain is a frequent and disabling condition with diverse underlying etiologies and is often difficult to treat. Systemic drug treatment is often limited in efficacy. Furthermore, adverse effects may be a limiting factor when trying to reach the necessary dose. Analgesics that can be applied topically have the potential to largely overcome this problem. They may be of particular advantage in localized neuropathic pain syndromes such as postherpetic neuralgia or small fiber neuropathy. Capsaicin, the pungent component of chili peppers, is a natural ligand of the transient receptor potential vanilloid 1 channel and has long been used as topically applicable cream with concentrations of 0.025 to 0.075\%. In 2009, a high-concentration transdermal capsaicin 8\% patch (Qutenza ; Acorda Therapeutics, Inc., Ardsley, NY, USA; Astellas Pharma Europe Ltd., Chertsey, Surrey, UK) was introduced for the treatment of peripheral neuropathic pain syndromes other than of diabetic origin in adults. It has since been widely used in diverse neuropathic pain disorders. In this review article, we summarize current knowledge on Qutenza, its advantages and problems, and expose unmet needs.},
  language  = {en}
}
@article{UeceylerTopuzoğluSchiesseretal.2011,
  author    = {{\"U}{\c{c}}eyler, Nurcan and Topuzoğlu, Teng{\"u} and Schießer, Peter and Hahnenkamp, Saskia and Sommer, Claudia},
  title     = {IL-4 Deficiency Is Associated with Mechanical Hypersensitivity in Mice},
  series = {PLoS One},
  volume    = {6},
  journal   = {PLoS One},
  number    = {12},
  doi       = {10.1371/journal.pone.0028205},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137924},
  pages     = {e28205},
  year      = {2011},
  abstract  = {Interleukin-4 (IL-4) is an anti-inflammatory and analgesic cytokine that induces opioid receptor transcription. We investigated IL-4 knockout (ko) mice to characterize their pain behavior before and after chronic constriction injury (CCI) of the sciatic nerve as a model for neuropathic pain. We investigated opioid responsivity and measured cytokine and opioid receptor gene expression in the peripheral and central nervous system (PNS, CNS) of IL-4 ko mice in comparison with wildtype (wt) mice. Na{\"i}ve IL-4 ko mice displayed tactile allodynia (wt: 0.45 g; ko: 0.18 g; p<0.001), while responses to heat and cold stimuli and to muscle pressure were not different. No compensatory changes in the gene expression of tumor necrosis factor-alpha (TNF), IL-1β, IL-10, and IL-13 were found in the PNS and CNS of na{\"i}ve IL-4 ko mice. However, IL-1β gene expression was stronger in the sciatic nerve of IL-4 ko mice (p<0.001) 28 days after CCI and only IL-4 ko mice had elevated IL-10 gene expression (p = 0.014). Remarkably, CCI induced TNF (p<0.01), IL-1β (p<0.05), IL-10 (p<0.05), and IL-13 (p<0.001) gene expression exclusively in the ipsilateral spinal cord of IL-4 ko mice. The compensatory overexpression of the anti-inflammatory and analgesic cytokines IL-10 and IL-13 in the spinal cord of IL-4 ko mice may explain the lack of genotype differences for pain behavior after CCI. Additionally, CCI induced gene expression of μ, κ, and δ opioid receptors in the contralateral cortex and thalamus of IL-4 ko mice, paralleled by fast onset of morphine analgesia, but not in wt mice. We conclude that a lack of IL-4 leads to mechanical sensitivity; the compensatory hyperexpression of analgesic cytokines and opioid receptors after CCI, in turn, protects IL-4 ko mice from enhanced pain behavior after nerve lesion.},
  language  = {en}
}
@article{UeceylerValetKafkeetal.2014,
  author    = {{\"U}{\c{c}}eyler, Nurcan and Valet, Michael and Kafke, Waldemar and T{\"o}lle, Thomas R. and Sommer, Claudia},
  title     = {Local and Systemic Cytokine Expression in Patients with Postherpetic Neuralgia},
  doi       = {10.1371/journal.pone.0105269},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-113041},
  year      = {2014},
  abstract  = {Background Postherpetic neuralgia (PHN) is the painful complication of a varicella zoster virus reactivation. We investigated the systemic and local gene expression of pro- and anti-inflammatory cytokine expression in patients with PHN. Methods Thirteen patients with PHN at the torso (Th4-S1) were recruited. Skin punch biopsies were obtained from the painful and the contralateral painless body area for intraepidermal nerve fiber density (IENFD) and cytokine profiling. Additionally, blood was withdrawn for systemic cytokine expression and compared to blood values of healthy controls. We analyzed the gene expression of selected pro- and anti-inflammatory cytokines (tumor necrosis factor-alpha [TNF] and interleukins [IL]-1β, IL-2, and IL-8). Results IENFD was lower in affected skin compared to unaffected skin (p<0.05), while local gene expression of pro- and anti-inflammatory cytokines did not differ except for two patients who had 7fold higher IL-6 and 10fold higher IL-10 gene expression in the affected skin compared to the contralateral unaffected skin sample. Also, the systemic expression of cytokines in patients with PHN and in healthy controls was similar. Conclusion While the systemic and local expression of the investigated pro- and anti-inflammatory cytokines was not different from controls, this may have been influenced by study limitations like the low number of patients and different disease durations. Furthermore, other cytokines or pain mediators need to be considered.},
  language  = {en}
}