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As hypersensitivity to natural rubber latex (NRL) has become an increasingly recognized problem in children, identification of all groups at risk seems important. In this study hypersensitivity to NRL was evaluated in 337 children with potential risk factors. We identified by questionnaire children's underlying diseases, history of surgical procedures, evidence of atopy and patient's history of NRL-specific reactions. Hypersensitivity to NRL and other allergens relevant in the Düsseldorf area was evaluated by skin prick test and specific IgE. In 9.2% of all children hypersensitivity to NRL was observed. Significant risk factors for hypersensitivity to NRL were, among the underlying diseases, spina bifida (odds ratio 29.2), hydrocephalus internus (10.1), gastrointestinal malformation (5.2) and atopy (2.2). Surgical procedures with significant risk were the implantation of a ventriculo-peritoneal shunt (15.7) and surgery of the gastrointestinal tract (3.1). Frequency of surgical procedures correlated (p < 0.001) with risk of hypersensitivity. Frequent surgery and atopy were found to have an additional effect on the risk of hypersensitivity. Information about previous NRL-specific reactions obtained by questionnaire was of little predictive value when performing multivariate analysis. For children at high risk for hypersensitivity to NRL preoperative evaluation and, in case of hypersensitivity, preventive measures seem to be advised.  相似文献   
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The prevalence of human herpesvirus 8 (HHV-8)/Kaposi's sarcoma (KS)-associated herpesvirus was investigated in the semen of 99 human immunodeficiency virus (HIV)-infected men (median CD4 cell count, 357/mm3) by use of a polymerase chain reaction (PCR) assay capable of detecting <10 copies of HHV-8 DNA. Of the subjects, 95 (96%) self-identified as men who have sex with men (MSM), and 3 had a history of clinical KS. Seminal cell specimens were negative for HHV-8 in 98 subjects. None of the 26 without KS (27.1% of 96 tested) who were seropositive for HHV-8 by IFA for latency-associated nuclear antigens had HHV-8 detected in their semen. The only subject with any evidence for seminal HHV-8 DNA was seropositive for HHV-8 and had active KS. HHV-8 was detected in 10 (10.4%) of 96 peripheral blood mononuclear cell specimens. The prevalence of HHV-8 DNA by PCR in semen of HIV-infected MSM without KS is low.  相似文献   
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The influence of ionic strength and composition on the binding and inhibition of human leukocyte elastase by glycosaminoglycans with variable degree and position of sulfation was investigated. The kinetic mechanism of inhibition had a hyperbolic, mixed-type character with a competitive component that was promoted by low ionic strength, reduced by phosphate ions, and which also depended on the substrate and glycosaminoglycan structure. Enzyme binding was a cooperative phenomenon that varied with ionic strength and composition. The inhibition patterns correlated with the cationic character of elastase and with the distribution of arginines on its molecular surface, most notably with residues located in the vicinity of the substrate binding region. The order of affinity for elastase binding was chondroitin 4-sulfate < chondroitin 6-sulfate < dermatan sulfate, iduronate-containing derivatives being superior with respect to the glucuronate-containing counterparts. Additional sulfation at both the 4- and 6- positions or at the N- and 4-positions of the N-acetylgalactosamine moiety decidedly improved the inhibitory efficiency. The results highlight a fundamental physiological role of enzyme-glycosaminoglycan interactions. In the azurophil granule of the human polymorphonuclear neutrophil, elastase and other enzymes are bound to a matrix of chondroitin 4-sulfate because this is the only glycosaminoglycan that simultaneously offers good binding for enzyme compartmentalization together with prompt release from the bound state at the onset of phagocytosis.  相似文献   
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The relative importance of fat and lean tissue mass in determining bone mineral mass among postmenopausal women was examined in this 1-year longitudinal study. Fifty postmenopausal Caucasian women entered the study; 45 of them completed a 1-year follow-up. Dual-energy X-ray absorptiometry was employed for measuring total and regional bone mineral density (BMD) and bone mineral content (BMC), fat tissue mass (FTM), lean tissue mass (LTM), and body weight. Results from linear regression analysis using the cross-sectional data (n = 50) of the study indicated that LTM explained a larger percentage of variation in bone mineral mass than did FTM. FTM and LTM were found to be moderately correlated (r = 0.55); when FTM was entered in the same predicting regression models, LTM was a significant predictor (p < 0.05) of the total and regional BMC, but not BMD. The percent FTM (and inversely %LTM) was correlated with BMD and BMC, but significant correlation was primarily found only for total body BMD (or BMC). Weight was the best predictor of total body BMD and BMC. Longitudinally (n = 45), annual changes in both FTM and weight were significantly associated with annual changes in regional BMD after adjustment for initial bone mineral values (p < 0.05). We conclude that bone mineral mass is more closely related to LTM than to FTM, while annual changes in regional BMD are more closely correlated with changes in FTM in healthy postmenopausal women. Meanwhile, increased body weight is significantly associated with increased bone mineral mass.  相似文献   
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John W. Larsen  Doyoung Lee 《Fuel》1985,64(7):981-984
A set of six coals ranging in rank from lignite to hvA bituminous was swollen with a series of alkyl-substituted pyridines and a smaller set of 4-alkylanilines. The size and branching of the alkyl groups was varied and the effect of this variation on the dissolution of the amines in the coal and the resulting coal swelling was measured volumetrically. In a few cases, substituents which hindered the amine nitrogen were studied. The lignite and subbituminous coal have a much higher tolerance to branched, bulky groups than do the bituminous coals. The presence of tertiary groups in a solute strongly inhibits their dissolution in bituminous coals. Bituminous coals behave as if extensive parallel packing of structures occurs. Often, they can accept very large planar groups but have a low capacity for branched groups.  相似文献   
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