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The aetiology of porphyria cutanea tarda (PCT) has not been elucidated, but the possibility of an autoimmune mechanism has been proposed. We report a case of an unknown clinical combination of PCT with autoimmune hypothyroidism, alopecia universalis and vitiligo with thyroid and parietal cell circulating antibodies. This is highly suggestive of underlying autoimmune damage in this patient.  相似文献   
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Diethyl maleate (DEM) which binds and thus depletes tissue glutathione levels was used to aggravate the injury and to determine its effect on incisional healing. A 5 cm dorsal midline skin incision was performed on 40 albino Wistar rats in two groups and then closed by interrupted sutures. Groups received 0.9% NaCl and DEM at a dosage of 1 mg/kg/day intraperitoneally for seven days, respectively. On postoperative days 7 and 14, histopathological assessment and tensile strengths were measured. The DEM treated group had a marked inflammation with poorly defined collagen formation and the tensile strength measurements revealed a significant decrease (p <0.001) on the 7t day. On the other hand, the first group showed better collagenization and a lesser degree of inflammation. However, on the 14th day, there was no noticeable histopathological difference between the two groups; but, tensile strength values of the second group were still lower (p <0.05). In this animal model, DEM postponed the healing process and reduced the tensile strength.  相似文献   
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A fibre optic potassium ion sensor has been developed based on reflectance measurements of the pH-dependent chromogenic crown ether 'Takagi reagent' immobilized on the non-ionic polymeric resin Amberlite XAD2. The sensor response is in the 1.5-100 mM range with a detection limit of 0.25 mM K+. The selectivity factor over sodium is 20. The proposed sensor works with a reproducibility of +/- 0.8% at the 5 mM K+ level. Advantageous design features include ease of construction, simplicity of use, reversibility, short response time (approximately 1 min) and an optimum working pH range (7.0-8.0) for biological fluids. This optical sensor was applied successfully to the direct determination of potassium in human serum. Aqueous potassium standards containing 0.13 M NaCl and a buffer of pH 8 were used for calibration.  相似文献   
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Back pain among nurses is a common problem. Prior studies of this problem have been based on cross-sectional or retrospective data. This 18-month prospective study involving nurses newly graduated from nursing school investigated personal, worksite, and training factors associated with future risk of back pain. Each nurse underwent a preliminary interview and periodic follow-ups to identify those with back injuries. Contingency tables and logistic regression analyses demonstrated that prior significant back pain episodes (evidenced by previous job changes because of back pain, frequent medication use, etc.) were associated with increased future risk. Training at nursing school or on the job did not have a protective effect. This pilot study therefore suggests factors useful in placement and counseling of new nurses and indicates the need for further implementation of mechanical lift assist device use. © 1994 Wiley-Liss, Inc.  相似文献   
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