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71.
To estimate ethanol consumption by university students attending a student health facility, a biochemical marker of alcohol intake [whole blood associated acetaldehyde (WBAA)] was quantified by fluorimetric HPLC. Over a two year period we studied blood samples, coded by date and sex, from 645 females and 332 males, and compared the results to previously established reference ranges for teetotalers by sex. Men had higher absolute values for WBAA than women (9.9 versus 9.5 microM in the present study). However, significantly greater numbers of women (74%) than men (44%) had WBAA levels above the 99th percentile for teetotalers. Variations occurred during the academic year, with significant elevations occurring in the late fall and winter months. Testing of WBAA levels in a student health service may be important especially for women to facilitate counseling on the dangers of alcohol abuse. 相似文献
72.
HJ Kock C Jurgens H Hirche J Hanke KP Schmit-Neuerburg 《Canadian Metallurgical Quarterly》1996,115(3-4):136-140
Anteroposterior X-ray views of both acromioclavicular (AC) joints with 10-kg weights held in each hand are the generally accepted procedure for diagnosis of Tossy I-III grades of AC joint separation. An analogous diagnosis can be made by standardized ultrasound examination. Ten individuals with Tossy-I, 11 with Tossy-II and 8 with Tossy-III instability were examined both radiographically and by B-mode ultrasound. The degree of AC joint separation was uniformly determined on the basis of a calculated index (AC Index = AC joint width of uninjured side/AC joint width of injured side). The mean AC Index for Tossy-I instability determined by ultrasound was 1.0; mean indices of 0.49 and 0.5 were determined for Tossy-II injury by ultrasound and X-ray, respectively, and of 0.21 and 0.2, respectively, for Tossy-III instability. Statistical analysis showed significant differences between the mean AC indices of all three groups (P < 0.0001). We conclude that the reliability of ultrasound examination of AC joint instability is equal to that of radiographic measurement. Standard X-rays of the shoulder remain mandatory only to exclude fracture. The indication for operative stabilization of the AC joint can be established on the basis of the grade of AC joint instability measured by the side-effect-free and cost-effective method of ultrasound examination (AC Index < 0.3 equivalent to Tossy-III instability). 相似文献
73.
SB delCardayre KP Stock GL Newton RC Fahey JE Davies 《Canadian Metallurgical Quarterly》1998,273(10):5744-5751
The human pathogen Staphylococcus aureus does not utilize the glutathione thiol/disulfide redox system employed by eukaryotes and many bacteria. Instead, this organism produces CoA as its major low molecular weight thiol. We report the identification and purification of the disulfide reductase component of this thiol/disulfide redox system. Coenzyme A disulfide reductase (CoADR) catalyzes the specific reduction of CoA disulfide by NADPH. CoADR has a pH optimum of 7.5-8.0 and is a dimer of identical subunits of Mr 49,000 each. The visible absorbance spectrum is indicative of a flavoprotein with a lambdamax = 452 nm. The liberated flavin from thermally denatured enzyme was identified as flavin adenine dinucleotide. Steady-state kinetic analysis revealed that CoADR catalyzes the reduction of CoA disulfide by NADPH at pH 7.8 with a Km for NADPH of 2 muM and for CoA disulfide of 11 muM. In addition to CoA disulfide CoADR reduces 4,4'-diphosphopantethine but has no measurable ability to reduce oxidized glutathione, cystine, pantethine, or H2O2. CoADR demonstrates a sequential kinetic mechanism and employs a single active site cysteine residue that forms a stable mixed disulfide with CoA during catalysis. These data suggest that S. aureus employs a thiol/disulfide redox system based on CoA/CoA-disulfide and CoADR, an unorthodox new member of the pyridine nucleotide-disulfide reductase superfamily. 相似文献
74.
OBJECTIVES: To test the hypothesis that the outcome of temporomandibular disorders (TMD) is not influenced by condylar position, asymmetry, angle or structural bone changes. METHODS: Eighty consecutive patients (60 women, 20 men) with an age range of 6-81 years, referred to the Department of Stomatognathic Physiology, were included in the study. The patients were clinically and radiologically examined before and at least 1 year after treatment. RESULTS: The most common clinical diagnoses among the patients were TMD with a neuromuscular background in 35% and osteoarthritis in 21%. Seventy-two per cent of the patients were symptom-free or better, 24% unchanged and 1% worse 1 year or more after treatment. After treatment the bone structure of the TMJ was unchanged in 83% of the patients, in 12% erosions healed and in 5% erosions developed. Almost all patients had some degree of condylar displacement on tomography before treatment. In the majority the condylar position was unchanged after treatment. CONCLUSION: No single radiographic finding was found to be related to the treatment outcome and therefore plain radiography has a minor role in the management of TMD. 相似文献
75.
Escherichia coli Rep helicase is a DNA motor protein that unwinds duplex DNA as a dimeric enzyme. Using fluorescence probes positioned asymmetrically within a series of single-stranded (ss) oligodeoxynucleotides, we show that ss-DNA binds with a defined polarity to Rep monomers and to individual subunits of the Rep dimer. Using fluorescence resonance energy transfer and stopped-flow techniques, we have examined the mechanism of ss-oligodeoxynucleotide binding to preformed Rep dimers in which one binding site is occupied by a single-stranded oligodeoxynucleotide, while the other site is free (P2S dimer). We show that ss-DNA binding to the P2S Rep dimer to form the doubly ligated P2S2 dimer occurs by a multistep process with the initial binding step occurring relatively rapidly with a bimolecular rate constant of k1 = approximately 2 x 10(6) M-1 s-1 [20 mM Tris (pH 7.5), 6 mM NaCl, 5 mM MgCl2, 5 mM 2-mercaptoethanol, and 10% (v/v) glycerol, 4 degrees C]. A minimal kinetic mechanism is proposed which suggests that the two strands of ss-DNA bound to the Rep homodimer are kinetically distinct even within the P2S2 Rep dimer, indicating that this dimer is functionally asymmetric. The implications of these results for the mechanisms of DNA unwinding and translocation by the functional Rep dimer are discussed. 相似文献
76.
MA Parry C Fernandez-Catalan A Bergner R Huber KP Hopfner B Schlott KH Gührs W Bode 《Canadian Metallurgical Quarterly》1998,5(10):917-923
Zinc, a common element of adenylate kinases from Gram-positive bacteria, binds to a structural motif consisting of three or four cysteine residues, Cys-X2-Cys-X16-Cys-X2-Cys/Asp. The enzyme from Paracoccus denitrificans, a Gram-negative bacterium, has structural features much similar to those of adenylate kinases from Gram-positive organisms [Spurgin, P., Tomasselli, A.G., and Schiltz, E. (1989) Eur. J. Biochem., 179, 621-628]. However, adenylate kinase isolated from this bacterium was not reported to bind metal. These findings prompted us to clone the corresponding gene of P. denitrificans, and to characterize the enzyme overproduced in Escherichia coli. The deduced primary structure of adenylate kinase from P. denitrificans revealed two differences from that previously published: Cys was found at position 130 instead of His, and His was found at position 138 instead of Gly. The recombinant enzyme is a dimer which binds either zinc or iron, in a metal/monomer ratio of one. The dissociating sulfhydryl reagent, p-(hydroxy-mercuri)phenylsulfonate, released the metal from the protein, confirming that thiols are involved in zinc- or iron-binding. The iron-chelated form of recombinant P. denitrificans adenylate kinase, which is essentially under reduced form, transfers electrons to the oxidized cytochrome c. In conclusion, the absence of metal in the enzyme isolated from P. denitrificans is not related to the protein structure but most probably due to the physiological properties of the host organism. 相似文献
77.
Survivorship analysis of the Kinematic Stabilizer total knee replacement: a 10- to 14-year follow-up
The Kinematic Stabilizer is a posterior-cruciate-substituting design of total knee replacement. We have reviewed 109 primary total knee replacements in 95 patients at a mean follow-up time of 12.7 years (10 to 14). We used survival analysis with failure defined as revision of the implant. This gave a cumulative survival rate of 95% (95% CI +/- 5%) at ten years and (87% +/- 10%) at 13 years. These results from an independent centre confirm the value of an established design of cemented total knee replacement and question the wisdom of the introduction of modifications and new designs without properly controlled trials. 相似文献
78.
79.
U Klangby I Okan KP Magnusson M Wendland P Lind KG Wiman 《Canadian Metallurgical Quarterly》1998,91(5):1680-1687
So-called sulfur-turf microbial mats, which are macroscopic white filaments or bundles consisting of large sausage-shaped bacteria and elemental sulfur particles, occur in sulfide-containing hot springs in Japan. However, no thermophiles from sulfur-turf mats have yet been isolated as cultivable strains. This study was undertaken to determine the phylogenetic positions of the sausage-shaped bacteria in sulfur-turf mats by direct cloning and sequencing of 16S rRNA genes amplified from the bulk DNAs of the mats. Common clones with 16S rDNA sequences with similarity levels of 94.8 to 99% were isolated from sulfur-turf mat samples from two geographically remote hot springs. Phylogenetic analysis showed that the phylotypes of the common clones formed a major cluster with members of the Aquifex-Hydrogenobacter complex, which represents the most deeply branching lineage of the domain bacteria. Furthermore, the bacteria of the sulfur-turf mat phylotypes formed a clade distinguishable from that of other members of the Aquifex-Hydrogenobacter complex at the order or subclass level. In situ hybridization with clone-specific probes for 16S rRNA revealed that the common phylotype of sulfur-turf mat bacteria is that of the predominant sausage-shaped bacteria. 相似文献
80.
DN O'Neal RC O'Brien KL Timmins GD Grieve KP Lau GC Nicholson MA Kotowicz JD Best 《Canadian Metallurgical Quarterly》1998,15(10):870-877
The aim of this study was to determine the effect of the lipid modifying agent gemfibrozil on lipid and coagulation risk factors in patients with Type 2 diabetes mellitus (Type 2 DM). Twenty-six subjects with Type 2 DM and dyslipidaemia were treated for 24 weeks with either gemfibrozil 600 mg orally twice daily or placebo in a double-blind randomized trial. Lipid profiles, fibrinogen, Factor VII, and plasminogen activator inhibitor-1 (PAI-1) were measured by routine laboratory methods. Low density lipoprotein (LDL) size was determined by gradient gel electrophoresis and the resistance of LDL to copper-induced oxidation was assessed by measuring absorbance at 234 nm. Gemfibrozil significantly reduced total cholesterol (-0.9 (-0.48, -1.32) mmol l(-1); p < 0.05) and triglycerides (-2.7 (-1.55, -1.35) mmol l(-1); p < 0.001) vs placebo. The fall in triglyceride was reflected by a fall in VLDL cholesterol levels in the gemfibrozil treated group vs placebo (-1.31 mmol l(-1); p < 0.001). LDL-cholesterol level did not change but LDL particle size increased by 0.5 nm (0.01, 0.93); P < 0.02. The increase in particle size was inversely correlated with the change of triglyceride level (r = -0.79, p < 0.0001) but did not result in any reduction of susceptibility to copper-induced oxidation. There were no significant changes in the coagulation parameters studied. Because of its ability to correct the lipid abnormalities associated with Type 2 DM particularly hypertriglyceridaemia, gemfibrozil provides a useful therapeutic option in the management of diabetic dyslipidaemia but it does not alter in vitro oxidizability of LDL. 相似文献