Visuomotor performance based on peripheral vision is impaired in the visual form agnostic patient DF

The perception-action model states that visual information is processed in different cortical areas depending on the purpose for which the information is acquired. Specifically, it was suggested that the ventral stream mediates visual perception, whereas the dorsal stream primarily processes visual information for the guidance of actions (Goodale & Milner, 1992). Evidence for the model comes from patient studies showing that patients with ventral stream damage (visual form agnosia) and patients with dorsal stream damage (optic ataxia) show divergent performance in action and perception tasks. Whereas DF, a patient suffering from visual form agnosia, was found to perform well in visuomotor tasks despite her inability to use vision for perceptual tasks, patients with optic ataxia show usually the opposite pattern, i.e. good perception but impaired visuomotor control. The finding that both disorders seem to provoke a mirror-reversed pattern of spared and impaired visual functions, led to the belief that optic ataxia and visual form agnosia can be considered as complementary disorders. However, the visuomotor performance of patients with optic ataxia is typically only impaired when they are tested in visual periphery while being often preserved when tested in central vision. Here, we show that DF's visuomotor performance is also only preserved when the target is presented centrally. Her reaching and grasping movements to targets in peripheral vision are abnormal. Our findings indicate that DF's visuomotor performance is quite similar to the visuomotor performance of patients with optic ataxia which undermines previous suggestions that the two disorders form a double-dissociation.     

Intraperitoneal adhesions--an ongoing challenge between biomedical engineering and the life sciences

Peritoneal adhesions remain a relevant clinical problem despite the currently available prophylactic barrier materials. So far, the physical separation of traumatized serosa areas using barriers represents the most important clinical strategy for adhesion prevention. However, the optimal material has not yet been found. Further optimization or pharmacological functionalization of these barriers could give an innovative input for peritoneal adhesion prevention. Therefore, a more complete understanding of pathogenesis is required. On the basis of the pathophysiology of adhesion formation the main barriers currently in clinical practice as well as new innovations are discussed in the present review. Physiologically, mesothelial cells play a decisive role in providing a frictionless gliding surface on the serosa. Adhesion formation results from a cascade of events and is regulated by a variety of cellular and humoral factors. The main clinically applied strategy for adhesion prevention is based on the use of liquid or solid adhesion barriers to separate physically any denuded tissue. Both animal and human trials have not yet been able to identify the optimal barrier to prevent adhesion formation in a sustainable way. Therefore, further developments are required for effective prevention of postoperative adhesion formation. To reach this goal the combination of structural modification and pharmacological functionalization of barrier materials should be addressed. Achieving this aim requires the interaction between basic research, materials science and clinical expertise.     

In vivo fluorescence confocal microscopy: indocyanine green enhances the contrast of epidermal and dermal structures

In recent years, in vivo skin imaging devices have been successfully implemented in skin research as well as in clinical routine. Of particular importance is the use of reflectance confocal microscopy (RCM) and fluorescence confocal microscopy (FCM) that enable visualization of the tissue with a resolution comparable to histology. A newly developed commercially available multi-laser device in which both technologies are integrated now offers the possibility to directly compare RCM with FCM. The fluorophore indocyanine green (ICG) was intradermally injected into healthy forearm skin of 10 volunteers followed by in vivo imaging at various time points. In the epidermis, accurate assessment of cell morphology with FCM was supplemented by identification of pigmented cells and structures with RCM. In dermal layers, only with FCM connective tissue fibers were clearly contoured down to a depth of more than 100 μm. The fluorescent signal still provided a favorable image contrast 24 and 48 hours after injection. Subsequently, ICG was applied to different types of skin diseases (basal cell carcinoma, actinic keratosis, seborrhoeic keratosis, and psoriasis) in order to demonstrate the diagnostic benefit of FCM when directly compared with RCM. Our data suggest a great impact of FCM in combination with ICG on clinical and experimental dermatology in the future.     

Anakinra in patients with treatment-resistant adult-onset Still's disease: four case reports with serial cytokine measurements and a review of the literature

OBJECTIVE: To determine the efficacy of the interleukin (IL)-1-receptor antagonist (IL-1RA) anakinra in patients with adult-onset Still's disease (AOSD) refractory to standard treatments such as glucocorticosteroids (GC), immunosuppressive drugs, and tumor necrosis factor (TNF)-antagonists; to verify disease remission objectively by serial cytokine measurements; and to review the current literature on anakinra for this indication. METHODS: Four patients with AOSD--2 with acute flares of the chronic form of the disease and 2 with intermittent disease--were treated with prednisolone and methotrexate. One was also treated with several other immunosuppressive drugs including etanercept and infliximab. One patient had life-threatening symptoms (toxic megacolon, pneumonitis, disseminated intravascular coagulation) despite high-dose prednisolone. Treatment with anakinra 100 mg/d subcutaneously was initiated. White blood cells (WBC), C-reactive protein (CRP) levels, erythrocyte sedimentation rate (ESR), liver enzymes, ferritin levels, and serum cytokines were analyzed. The current literature on the efficacy of anakinra for AOSD is reviewed. RESULTS: Patients with chronic AOSD quickly responded to anakinra treatment (1 day to 3 days). GC could be tapered. ESR, CRP, WBC, ferritin, and liver enzymes returned to normal. Serum cytokine measurements revealed moderately elevated IL-1beta levels and highly elevated IL-18 levels in active disease, which normalized with anakinra. TNF-alpha and IL-6 were moderately elevated only in the 2 patients with chronic AOSD. In the literature, 17 similar cases have been reported to date. CONCLUSIONS: Anakinra is effective in treatment-resistant and in life-threatening AOSD. IL-18 serum levels, in addition to CRP, ESR, liver enzymes, ferritin, and WBC, may be helpful in assessing disease activity and response to treatment.     

Postnatal Schwann cell proliferation but not myelination is strictly and uniquely dependent on cyclin-dependent kinase 4 (cdk4)

Peripheral myelin formation depends on axonal signals that tightly control proliferation and differentiation of the associated Schwann cells. Here we demonstrate that the molecular program controlling proliferation of Schwann cells switches at birth. We have analyzed the requirements for three members of the cyclin-dependent kinase (cdk) family in Schwann cells using cdk-deficient mice. Mice lacking cdk4 showed a drastic decrease in the proliferation rate of Schwann cells at postnatal days 2 and 5, but proliferation was unaffected at embryonic day 18. In contrast, ablation of cdk2 and cdk6 had no significant influence on postnatal Schwann cell proliferation. Taken together, these findings indicate that postnatal Schwann cell proliferation is uniquely controlled by cdk4. Despite the lack of the postnatal wave of Schwann cell proliferation, axons were normally myelinated in adult cdk4-deficient sciatic nerves. Following nerve injury, Schwann cells lacking cdk4 were unable to re-enter the cell cycle, while Schwann cells deficient in cdk2 or cdk6 displayed proliferation rates comparable to controls. We did not observe compensatory effects such as elevated cdk4 levels in uninjured or injured nerves of cdk2 or cdk6-deficient mice. Our data demonstrate that prenatal and postnatal Schwann cell proliferation are driven by distinct molecular cues, and that postnatal proliferation is not a prerequisite for the generation of Schwann cell numbers adequate for correct myelination.     

Reattachment of an avulsed distal biceps tendon in athletes

Refixation of the ruptured distal biceps tendon to the radial tuberosity in a two-incision technique restores power and function. Between 1995 and 1999 a refixation of the ruptured distal biceps brachii tendon on the tuberositas radii was performed in four athletes (three gymnasts and one American football player) using a two-incision-technique according to Boyd and Anderson (J Bone Joint Surg 43A:1041–1043, 1961) modified by Bourne and Morrey (Clin Orthop 271:143–148, 1991). The average age at surgery was 36 (23–48) years. The patients were followed up with a clinical examination and a questionnaire at an average of 82 (70–108) months postoperative. Flexion, extension and pronation was normal in all patients, although two patients had a reduction of forearm supination of 10° on the operated side. On a visual analogue scale, a subjective 5–10% reduction of forearm-flexion strength was reported by three patients. No decrease of flexion- or supination-strength was observed upon clinical examination. The subjective rating of the overall clinical outcome was “excellent” in three and “good” in one patient. Three patients rated “excellent” and one patient “good” according to the criteria of Rantanen and Orava (Am J Sports Med 27:128–132, 1999). We conclude that power and function can be restored through a refixation of the ruptured distal biceps tendon to the radial tuberosity in a two-incision technique. We recommend the method in athletes.     

S1 Guideline onychomycosis

Onychomycosis is a fungal infection of the fingernails and toenails. In Europe, tinea unguium is mainly caused by dermatophytes. The diagnostic workup comprises microscopic examination, culture and/or molecular testing (nail scrapings). Local treatment with antifungal nail polish is recommended for mild or moderate nail infections. In case of moderate to severe onychomycosis, oral treatment is recommended (in the absence of contraindications). Treatment should consist of topical and systemic agents. The aim of this update of the German S1 guideline is to simplify the selection and implementation of appropriate diagnostics and treatment. The guideline was based on current international guidelines and the results of a literature review conducted by the experts of the guideline committee. This multidisciplinary committee consisted of representatives from the German Society of Dermatology (DDG), the German-Speaking Mycological Society (DMykG), the Association of German Dermatologists (BVDD), the German Society for Hygiene and Microbiology (DGHM), the German Society of Pediatric and Adolescent Medicine (DGKJ), the Working Group for Pediatric Dermatology (APD) and the German Society for Pediatric Infectious Diseases (DGPI). The Division of Evidence-based Medicine (dEBM) provided methodological assistance. The guideline was approved by the participating medical societies following a comprehensive internal and external review.