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81.
BACKGROUND: The association of serum lipids with coronary heart disease has been studied extensively in middle-aged men and, to a lesser extent, in similar women. Less well defined are lipid variables predictive of CHD in individuals of age > or = 60 years. METHODS AND RESULTS: The Systolic Hypertension in the Elderly Program recruited 4736 persons (mean age, 72 years; 14% were black; and 43% were men). Mean systolic and diastolic blood pressures were 170 and 77 mm Hg, respectively. Baseline mean total cholesterol was 6.11 mmol/L (236 mg/dL); HDL cholesterol, 1.39 mmol/L (54 mg/dL); and non-HDL cholesterol, 4.72 mmol/L (182 mg/dL). Triglyceride levels were 1.62 mmol/L (144 mg/dL) for fasting participants and 1.78 mmol/L for the total group. LDL cholesterol, estimated in fasting samples with triglycerides of < 4.52 mmol/L, averaged 3.98 mmol/L (154 mg/dL). Mean follow-up was 4.5 years. In multivariate Cox regression analyses, baseline total, non-HDL, and LDL cholesterol levels and the ratios of total, non-HDL, and LDL to HDL cholesterol were significantly related to CHD incidence. HDL cholesterol and triglycerides were not significant in these analyses. In fasting participants with triglyceride levels of < 4.52 mmol/L, a 1.03 mmol/L (40 mg/dL) higher baseline total, non-HDL, or LDL cholesterol was associated with a 30% to 35% higher CHD event rate. CONCLUSIONS: The results of this study support the concept that serum lipids are CHD risk factors in older Americans.  相似文献   
82.
83.
A prospective study of 66 consecutive patients with cardiac wounds seen over a 27-month period is reported. No patient was excluded. Patients were stratified by injury mechanism and by physiologic scoring at admission using the cardiovascular-respiratory elements of the Trauma Score (CVRS). Admission cardiac rhythm was obtained in patients with a CVRS of 0 and a Glasgow Coma Scale (GCS) score of 3. Information concerning the anatomic extent of the cardiac wound, the presence or absence of tamponade, and the degree of injury to other structures was also collected prospectively. Seventy percent of the cardiac wounds were caused by gunshots. The probability of successful resuscitation was significantly related to mechanism of injury and physiologic condition on arrival. Among patients arriving with a CVRS of 0 and a GCS score of 3, survival correlated with cardiac rhythm. Pericardial tamponade did not prove to be an independent predictor of early survival. The presence of tamponade was statistically linked to the mechanism of injury. Transport by non-official conveyance was associated with a higher CVRS on arrival. Intoxication with alcohol or cocaine had no evident effect on resuscitation probability.  相似文献   
84.
In order to help establish criteria for optimizing protocols for in vivo mutation studies, lacZ transgenic mice (Muta mouse) were treated with five consecutive daily doses of ethylnitrosourea (50 mg/kg), sampled at times up to 55 days after treatment, and mutant frequencies and DNA sequences determined for liver and bone marrow. In the bone marrow, the mutant frequency rose very rapidly in the first 5 days after treatment to 34 times the control frequency. Subsequently, there was a brood peak where the mutant frequency did not vary significantly, although it did appear to begin to decline after 45 days. In contrast, in the liver, the peak mutant frequency (11 times the control frequency) was not achieved until 35 days, after which there appeared to be a slow decline up to 55 days, which was not statistically significant. Once the maximum mutant frequency was reached, the mutation spectra in the two tissues were indistinguishable. In contrast to the G:C-->A:T transitions in 5'-CpG sites characteristic of untreated mice, A:T-->T:A transversions and A:T-->G:C transitions were prominent in both liver and bone marrow of ENU-treated mice, suggesting the involvement of unrepaired O2- and O4-ethylthymine adducts. In addition, G:C-->T:A transversions were induced in liver. This study demonstrates the possibility that although tissues may have different mutation fixation times, a single mutation fixation time equal to the longest time may be appropriate for in vivo mutation studies, provided that the mutation frequency does not decline appreciably after the peak is reached. This study also illustrates the necessity of ensuring that mutation characteristics are determined after optimal fixation has occurred.  相似文献   
85.
The Paired Associate Recognition Test (PART) was developed to measure declarative memory using Wisconsin Card Sorting Test (WCST) stimuli, so that both tasks could be administered during functional neuroimaging to differentiate memory and executive function, and associated frontal and temporal lobe activation in schizophrenia. The current study was designed to compare PART and WCST performance in schizophrenic patients and to examine effects of medication and symptomatology. The PART, WCST, and standard declarative memory tasks were administered to 30 chronic schizophrenic patients and 30 matched healthy control subjects. Supporting task validity was the finding that patients were equally impaired on the PART and the WCST. Neuroleptics did not appear to affect performance. The effect of anticholinergic medication correlated negatively with WCST performance in a small subsample. Severity of schizophrenia-specific symptoms measured at intake on the Brief Psychiatric Rating Scale correlated negatively with performance on the WCST. These results support the application of the PART and WCST in future functional neuroimaging studies.  相似文献   
86.
Phenotypic analysis of antigen-specific T lymphocytes   总被引:4,自引:0,他引:4  
Identification and characterization of antigen-specific T lymphocytes during the course of an immune response is tedious and indirect. To address this problem, the peptide-major histocompatability complex (MHC) ligand for a given population of T cells was multimerized to make soluble peptide-MHC tetramers. Tetramers of human lymphocyte antigen A2 that were complexed with two different human immunodeficiency virus (HIV)-derived peptides or with a peptide derived from influenza A matrix protein bound to peptide-specific cytotoxic T cells in vitro and to T cells from the blood of HIV-infected individuals. In general, tetramer binding correlated well with cytotoxicity assays. This approach should be useful in the analysis of T cells specific for infectious agents, tumors, and autoantigens.  相似文献   
87.
Vinyl chloride (VC) workers are known to be at risk for development of liver angiosarcoma, a rare tumor. Previously, more than 80% of VC workers with liver angiosarcoma have been found to have an Asp-13 c-Ki-ras oncogene mutation, and more than 50% of VC-exposed workers without liver tumors were found to have Asp13-Ki-ras oncoprotein in their plasma. Some workers in Taiwan had also been exposed to VC, and some have contracted liver tumors. In this study, we used enhanced chemiluminescence Western blotting to detect Asp13-p21-Ki-ras in the sera of VC-exposed workers in Taiwan. There were 14 of 113 (12.4%) VC workers positive for the Asp13-Ki-ras oncoprotein in plasma, but 0 of 18 controls were positive. There were 10 of 69 (14.5%) plasma-positives among the more highly exposed (> 1000 ppm-months) workers and 4 of 48 (9.1%) plasma-positives among the lesser exposed (< or = 1000 ppm-months). Compared with the unexposed controls, the odds ratios (and 95% confidence intervals [CI]) for plasma-positivity were 4.11 (95% CI = 0.21, 80.4) in the lower-exposed workers and 6.53 (95% CI = 0.37, 116.9) in the higher-exposed workers, and there was a linear trend between exposure and plasma-positivity (P = 0.073). After adjusting for age and drinking status, the odds ratios (and 95% CIs) were 1.64 (95% CI = 0.17, 15.8), and 2.65 (95% CI = 0.42, 16.8), respectively, and there was a significant linear trend between exposure and plasma-positivity (P = 0.048). In summary, Asp13-Ki-ras oncoprotein can be found in the plasma of VC workers in Taiwan, and a significant dose-response relationship exists between plasma oncoprotein expression and VC exposure.  相似文献   
88.
OBJECTIVES: To study the effect of body fat distribution in women of reproductive age on fecundity. DESIGN: Prospective cohort study of all women who had entered a donor insemination programme. SETTING: One fertility clinic serving a large part of the midwest of the Netherlands. SUBJECTS: Of 542 women attending the clinic for artificial insemination for the first time, 500 women were eligible for study. MAIN OUTCOME MEASURES: Probability of conception per cycle and number of insemination cycles before pregnancy or stopping treatment. RESULTS: A 0.1 unit increase in waist-hip ratio led to a 30% decrease in probability of conception per cycle (hazard ratio 0.706; 95% confidence interval 0.562 to 0.887) after adjustment for age, fatness, reasons for artificial insemination, cycle length and regularity, smoking, and parity. Increasing age was significantly related to lower fecundity (p < 0.05); very lean and obese women were less likely to conceive (p < 0.10) as were women with subfertile partners (p < 0.10). All other exposure variables were not significantly related to fecundity. CONCLUSIONS: Increasing waist-hip ratio is negatively associated with the probability of conception per cycle, before and after adjustment for confounding factors. Body fat distribution in women of reproductive age seems to have more impact on fertility than age or obesity.  相似文献   
89.
This study was designed to evaluate factors that affect blood volumes transferred to skin during simulated needlestick injuries in an in vitro paper prefilter model and an ex vivo porcine tissue model. The effect of needle type and size, penetration depth, and glove use on the volume of radiolabeled blood transferred was determined in each model. Blood volumes ranged from 0.47 +/- 0.26 microL (30-gauge needle, 0.5-cm depth, in vitro model) to 5.88 +/- 1.45 microL (18-gauge needle, 2.0-cm depth, in vitro model). Needle size and penetration depth were significantly associated with transfer volume. Glove material reduced the transferred blood volume by 46%-86% in both models. Transfer volumes were within the same order of magnitude for all conditions. Hence, virus titer in the source blood may be a better predictor of needlestick infectivity than is exposure volume. Regardless, gloves may exert some protective effect and should be worn whenever needles are handled.  相似文献   
90.
Since the beginning of the twentieth century, different methods to control the quality of analyses have been in use. The advent of modern analytical instruments has prompted the need for such controls. In a modern clinical chemistry laboratory, quality control is an important tool to maintain the high predictive value of the methods in use. In this article the most important aspects of quality control are outlined. For further study, I recommend the references listed at the end of this article.  相似文献   
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