A model-based detector of vertex waves and K complexes in sleep electroencephalogram.

A model of sleep phasic events such as vertex waves, K complexes, delta waves and sleep spindles is proposed. It consists of feedback loops that are driven by white noise (simulating tonic delta and sigma activity) and by isolated random impulses, simulating vertex waves or K complexes, depending on the background tonic activity. A model-based method for the detection of sleep phasic events was implemented in a personal computer. Its performance was investigated using simulated and real whole-night EEG signals. The method was able to detect K complexes and vertex waves in a reliable way in spite of their variable shapes and in the presence of a variety of background activities. The detector appears to have superior performance to those so far reported in the literature. The performance of the detector was also compared to that of an electroencephalographer using normal sleep EEG records of 8 h duration from 6 subjects. The performance was satisfactory both in terms of accuracy and reliability. The problem of detecting K complexes in stages 3 and 4 of sleep is discussed.     

Gas chromatographic assay of methyltestosterone in tablets.

A simple gas chromatographic procedure has been developed for the determination of methyltestosterone in bulk powders and in tablets. Two new silyl ether derivatives of methyltestosterone have been prepared using dimethylethylsilylimidazole (DMESI) and dimethylisopropylsilylimidazole (DMiPSI). The method is accurate and selective for methyltestosterone within the concentration range 0.1-1.5 micrograms microliters-1.     

Cultures of Langerhans cells and co-culture with lymphoid cells: Relevance to toxicology and pharmacology

Langerhans cells are an essential component of cutaneous immunological defence mechanisms. They are mononuclear dendritic cells derived from bone marrow, which are present in the squamous epithelia, particularly skin. Langerhans cells show marked changes in phenotype and function when epidermal cell suspensions are prepared according to a trypsinization protocol and placed in culture for 1–3 days. They seem to mature and acquire most of the features of lymphoid dendritic cells, especially the interdigitating dendritic cells present in lymph nodes. This observation supports the assertion that resident Langerhans cells take up foreign antigens and then migrate through dermal lymphatics to local lymph nodes where they function as antigen-presenting cells. Thus, Langerhans cells play a pivotal role in the primary immune response and in the pathogenesis of skin diseases. In the past, most therapeutic treatment of skin diseases was achieved by administration of pharmacological agents by epicutaneous application. More recently, the determination of the toxicity of drugs and their pharmacological mechanisms has required the development of in vitro models to explore their potential effects at the cellular level. The effects of different agents (physical and chemical) on the density and function of fresh or cultured Langerhans cells are reviewed.     

Frühes Ovarialkarzinom

Patients with early ovarian carcinoma have a much better survival outcome than patients with more advanced disease. Comprehensive surgical staging is crucial for the determination of prognosis and treatment planning. During 2003, the first randomized trials were published demonstrating that adjuvant platinum based chemotherapy improves recurrence free and overall survival. Current treatment recommendations are largely based on the results of these studies. Accordingly, systemic adjuvant therapy should be offered to patients with disease stage Ib or higher and to patients with moderately differentiated or undifferentiated tumors. Due to incomplete surgical staging, the stage of disease in the patients included in these studies is probably underestimated, and only a fraction of the actual advanced stage patients is included.     

Systematic review of methods to diagnose infection in foot ulcers in diabetes.

AIM: To undertake a systematic review of the diagnostic performance of clinical examination, sample acquisition and sample analysis in infected foot ulcers in diabetes. METHODS: Nineteen electronic databases plus other sources were searched. To be included, studies had to fulfil the following criteria: (i) compare a method of clinical assessment, sample collection or sample analysis with a reference standard; (ii) recruit diabetic individuals with foot ulcers; (ii) present 2 x 2 diagnostic data. Studies were critically appraised using a 12-item checklist. RESULTS: Three eligible studies were identified, one each on clinical examination, sample collection and sample analysis. For all three, study groups were heterogeneous with respect to wound type and a small proportion of participants had foot ulcers due to diabetes. No studies identified an optimum reference standard. Other methodological problems included non-blind interpretation of tests and the time lag between index and reference tests. Individual signs or symptoms of infection did not prove to be useful tests when assessed against punch biopsy as the reference standard. The wound swab did not perform well when assessed against tissue biopsy. Semiquantitative analysis of wound swab might be a useful alternative to quantitative analysis. The limitations of these findings and their impact on recommendations from relevant clinical guidelines are discussed. CONCLUSION: Given the importance of this topic, it is surprising that only three eligible studies were identified. It was not possible to describe the optimal methods of diagnosing infection in diabetic patients with foot ulceration from the evidence identified in this systematic review.