氯仿重结晶棉酚的质量研究

报道了氯仿重结晶的棉酚的化学性质,样品在不同温度下干燥恒重后,经熔点、薄层层析、紫外光谱、红外光谱、X-射线衍射、热重量分析、元素(C,H,Cl)分析及棉酚合量测定等一系列的分析,确证了在60℃以下棉酚与氯仿成溶剂化物(solvate)。随着干燥温度的升高或在室温长时间的贮存,此现象逐渐消失,100℃真空干燥恒重后成为纯棉酚。     

Human fibroblast tissue factor is inhibited by lipoprotein-associated coagulation inhibitor and placental anticoagulant protein but not by apolipoprotein A-II

Studies of proteins that inhibit tissue factor activity have generally been conducted using either an extracted tissue homogenate ("thromboplastin") or tissue factor protein reconstituted into phospholipid vesicles rather than with tissue factor expressed in cell membranes (its physiological environment). In the present study, a human fibroblast cell strain was used to evaluate the effects of lipoprotein associated coagulation inhibitor (LACI), placental anticoagulant protein (PAP), and apolipoprotein A-II (apo A-II) on human tissue factor in cell membranes. LACI was tested from 7.8 to 500 pmol/L on fibroblasts cultured at cell densities ranging from 3,500 to 9,925 cells/well, and caused a progressive inhibition of tissue factor activity. PAP was tested from 3.9 nmol/L to 1 mumol/L at cell densities ranging from 4,500 to 15,400 cells/well and caused up to 83% inhibition of tissue factor activity. Inhibition by these proteins appeared to be influenced by cell density as well as whether the cells were intact or disrupted. Apo A-II, up to 1 mumol/L, did not inhibit the tissue factor activity of intact or disrupted fibroblasts at any cell density examined even though it did inhibit the activity of tissue factor in phospholipid vesicles. Of these inhibitors of tissue factor-dependent activation of factor X, LACI was the most effective in suppressing the generation of factor Xa activity. The effects obtained with apo A-II are clearly dependent on the nature of the tissue factor preparation with which it is tested. The disparity between the inhibitory effect of apo A-II on the activity of tissue factor reconstituted into lipid vesicles and the absence of effect on the activity of tissue factor remaining in cell membranes serves to reemphasize the necessity of reexamining results obtained with model systems using as nearly physiological reagents as possible.     

Test reproducibility of the API (20E), Enterotube, and Pathotec systems.

Thirty-three strains of bacteria (30 Enterobacteriaceae and one strain each of Aeromonas formicans, A. hydrophila, and Plesiomonas shigelloides) were tested three times in each of 27 conventional tests and in the API, Enterotube, and Pathotec systems. The results obtained were analysed for test reproducibility within each kit, correlation of the kit tests with the equivalent conventional media, and the identification of the strains by the kits. Difficulties in evaluation and comparison of identifications are discussed. A practical evaluation of the kits was also made.     

Myosin VIIA gene: heterogeneity of the mutations responsible for Usher syndrome type IB

Usher syndrome is recognized as the most frequent cause of hereditary deaf-blindness. Usher syndrome type I (USH1), the most severe form of the disease, is characterized by profound congenital sensorineural deafness, constant vestibular dysfunction, and retinitis pigmentosa of prepubertal onset. This form is genetically heterogeneous and five loci (USH1A-E) have been mapped thusfar. However, only the gene responsible for USH1 B (which accounts for approximately 75% of USH1 cases) has been characterized. It encodes a long-tailed unconventional myosin, myosin VIIA, with a predicted 2215 amino acid sequence. Primers covering the complete myosin VIIA coding sequence as well as the 3' non coding sequence were designed, allowing direct sequence analysis of each of the 48 coding exons and flanking splice sites in seven patients affected by USH1. Four novel mutations were thereby identified. The possibility should now be considered of a sequence-based prenatal diagnosis in some of the families affected by this very severe form of Usher syndrome.      

A series of Infections due to Capnocytophaga spp. in immunosuppressed and immunocompetent patients

Objective  To investigate the epidemiology, microbiology and outcome of infections caused by Capnocytophaga spp. at a single center.
Methods  We report on ten documented infectious episodes caused by Capnocytophaga observed between 1994 and 1999 at the Innsbruck University Hospital.
Results  In seven of ten patients, Capnocytophaga septicemia was diagnosed during periods of neutropenia. In contrast, the remaining three patients had normal white blood cell counts when acquiring Capnocytophaga septicemia (one) and pleural empyema (two). Blood cultures containing long, slender, Gram-negative rods, which grew slowly under anaerobic conditions and lacked susceptibility to metronidazole, were subcultivated in a CO₂-enriched atmosphere (5%). Subcultivation yielded Capnocytophaga in all ten cases within 2–12 days. The patients were then placed on appropriate antibiotic therapy, with or without additional surgical intervention, and the organism was eradicated.
Conclusion  Identification of Capnocytophaga facilitates appropriate, and in most cases effective, antimicrobial therapy.