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81.
HDL cholesterol (HDL-C) levels are inversely related to coronary heart disease (CHD) risk, and HDL-C distributions vary among countries. Poland is one of the few developed countries in which CHD rates are increasing at the same time that US rates have been falling, but whether these differences are explained by differences in risk factors such as HDL-C has not been determined. To examine this possibility, levels of HDL-C and its subfractions were compared in US and Polish urban and rural men and women aged 45 to 64 years. Age-adjusted HDL-C means were 0.20 mmol/L higher in urban Polish men and 0.37 mmol/L higher in rural Polish men than in their US counterparts (P < .0001); means in urban Polish women were 0.06 mmol/L higher (P < .05) and in rural Polish women 0.09 mmol/L higher (P < .001) than in their US counterparts. Adjustment for age, education, alcohol intake, smoking, BMI, heart rate, and menopause status (in women) had little effect on differences. Means of HDL2 and HDL3 levels showed similar between-country differences, although differences were minimal for HDL2 in urban men and women, and HDL3 means did not differ between rural women. BMI was inversely related to HDL-C and both subfractions in all gender-country-site strata (P < .001), and alcohol was directly related to HDL-C (P < .001) in all strata except Polish women. Cigarette smoking was negatively related to HDL-C and both subfractions in all US samples except HDL2 in urban men, whereas in Polish samples, significant associations were found only in urban women for HDL-C and in rural and urban women for HDL3. Age, heart rate, and education showed inconsistent or no association with HDL-C and its subfractions in either country. This profile of HDL-C and its subfractions in Polish samples contrasts sharply with the opposite trend in CHD mortality rates, which suggests either that other risk factors may account for the trends or that the relationship between HDL-C and CHD may differ between the two countries.  相似文献   
82.
We report herein the phenotypic and functional analysis of human bone marrow and thymus derived early T cells. Commitment to T cell lineage is acquired during CD7 antigen expression by CD34+ precursors in human bone marrow and before thymus colonization. Early thymocytes show similar phenotypic characteristics as bone marrow T cells. They rapidly acquire CD4 before the dual expression of CD4 and CD8. Their expansion and differentiation is regulated by two major factors: thymic stroma and cytokines produced by these stroma cells or by thymocytes themselves. Among cytokines, IL1 and sCD23 produced by thymic epithelial cells support in vitro early T cell development.  相似文献   
83.
The spectrum of infectious disease (ID) emergencies in hospitalized patients was assessed in a prospective study of 3,626 inpatient ID consultations in a 1,350-bed teaching hospital. ID emergencies, defined by a need or anticipated need for advanced life support or by irreversible organ damage leading to permanent functional loss, were encountered in 175 patients. Infections of the central nervous system (26.3%), cardiovascular system (14.9%), alimentary system (13.1%), and lower respiratory tract (7.4%) and adverse reactions to antimicrobial agents (7.4%) were most common. In 18.9% of the cases, the referring clinicians were unaware of the emergency at the time of referral. Drug reactions (46.1%), severe alimentary and peritoneal infections (32.0%), upper respiratory tract infections (28.6%), and skin and soft-tissue infections (27.3%) were most frequently missed. The emergency ID conditions were not recognized because they had an atypical presentation (51.5%), were not commonly seen in the referring specialty (24.2%), were due to rare organisms (15.2%), or had unusual anatomical sites of involvement (9.1%). A close liaison between clinicians and the ID team is crucial for recognition of ID emergencies at their early stages so that appropriate investigations and management can be instituted expediently, before the occurrence of irreversible damage.  相似文献   
84.
Brown trout (Salmo trutta L.) is a native fish of the rivers of northern Spain. It is the dominant fish species in these rivers, and it is widespread over all the range of freshwater ecosystems in the area, including ecosystems potentially polluted with heavy metals. In this study, the potential of brown trout as biomonitor of heavy metal pollution and the effect of fish age on the reliability of the assessment are analyzed. Copper, lead, and cadmium concentrations of both abiotic compartments (water and sediments) and brown trout (S. trutta) from three northern Spanish rivers were analyzed. Significant correlations were found between sediment lead content and lead concentration in trout liver. One-year-old juvenile trouts were demonstrated to be useful as a biomonitor of copper and lead pollution, revealing between-location differences. Older trouts do not seem adequate to properly monitor heavy metal pollution. The effect of aging on the reliability of this species as biomonitor is discussed.  相似文献   
85.
OBJECTIVE: In the postmenopausal years, women develop a central pattern of fat distribution and an increased risk of developing cardiovascular disease (CVD). The possibility that these events are related has not been extensively investigated. The object of the present study was to test the hypotheses that, 1) menopause-related differences in lipids are associated with greater estimated intra-abdominal adiposity, and 2) the relationship between individual adipose depots and plasma lipids differs with menopausal status. DESIGN: Cross-sectional. SUBJECTS: 141 healthy pre- and postmenopausal women aged 35-65 y. MEASUREMENTS: Total body fat by hydrodensitometry was used as an index of whole-body adiposity, the sum of five central skinfold measurements as an index of subcutaneous upper-body adiposity, and estimated intra-abdominal adipose tissue (IAF) as an index of visceral adiposity. Fasting plasma concentrations of total cholesterol (total-C), high- and low-density-lipoprotein cholesterol (HDL-C, LDL-C), and triglycerides were used as indices of CVD risk. RESULTS: Postmenopausal women had greater total body fat (P < 0.001), summed central skinfolds (P < 0.01), estimated IAF (P < 0.001), higher plasma concentrations of total-C (P < 0.001), LDL-C (P < 0.001) and triglycerides (P < 0.001), than premenopausal women. The relationship between central skinfolds and LDL-C differed with menopausal status, being significant in pre- but not postmenopausal women. Adjustment for estimated IAF with analysis of covariance decreased menopause-related differences in levels of total-C, LDL-C and triglycerides by approx 40-70%. CONCLUSION: These observations suggest that, 1) menopause-related changes in IAF may adversely affect the plasma lipid profile, and 2) menopausal status affects the relationship between central subcutaneous fat and LDL-C. Studies with measured IAF are needed to confirm present results.  相似文献   
86.
Experimental data from protein engineering studies and NMR spectroscopy have been used by theoreticians to develop algorithms for helix propensity and to benchmark computer simulations of folding pathways and energy landscapes. Molecular dynamic simulations of the unfolding of chymotrypsin inhibitor 2 (CI2) have provided detailed structural models of the transition state ensemble for unfolding/folding of the protein. We now have used the simulated transition state structures to design faster folding mutants of CI2. The models pinpoint a number of unfavorable local interactions at the carboxyl terminus of the single alpha-helix and in the protease-binding loop region of CI2. By removing these interactions or replacing them with stabilizing ones, we have increased the rate of folding of the protein up to 40-fold (tau = 0.4 ms). This correspondence, and other examples of agreement between experiment and theory in general, Phi-values and molecular dynamics simulations, in particular, suggest that significant progress has been made toward describing complete folding pathways at atomic resolution by combining experiment and simulation.  相似文献   
87.
OBJECTIVES: Transitional cell carcinomas of upper urinary tract (uttTCC) constitute 5% to 6% of all urothelial tumors. Ureteropyeloscopy has become the standard for clinical evaluation of uutTCC. Moreover, endoscopic treatments have been advocated as a conservative approach for low grade tumors or patients with intermediate grade tumors whose renal function is compromised. Therefore, grading has become the most predictive variable in defining therapeutic approach. In addition to morphologic evaluation, a series of biologic markers may be used to increase the accuracy of grading such as DNA analysis and p53 protein expression. In this study, we have evaluated these markers by means of cell image analysis with the SAMBA 400 system. METHODS: Thirteen cases of uttTCC were studied with cytologic smear, cell block, and histologic confirmation. DNA analysis was performed on cytologic smear. Immunostaining was performed on cell blocks. A grade was assigned on the basis of DNA evaluation and p53 expression quantitation. These grades were combined for each case and compared with the initial cytologic grading and the final histologic grading. RESULTS: Cytology alone diagnosed TCC in all but 1 case that was diagnosed atypical. Discrepancies were found in primary grading: cytologic grading concurred with histologic grading in 6 of the 13 cases. CONCLUSIONS: These results, although in a limited but selected number of cases, show the potential of computerized evaluation of biologic markers as parameters for a more objective grading of tumors.  相似文献   
88.
Human herpesvirus 8 (HHV-8) DNA sequences were examined in peripheral blood mononuclear cell (PBMC) DNA samples of 56 children, 15 healthy adults, and 10 renal transplant patients by the polymerase chain reaction (PCR). The PCR amplification was carried out using the published KS330(233) primer pairs to amplify HHV-8 DNA sequences. The PCR-amplified products were confirmed by Southern blot hybridization with radiolabeled 233 bp HHV-8 DNA fragment, which was cloned and sequenced from the PCR-amplified product of Kaposi's sarcoma tissue. Six PCR-amplified product of four children and two renal transplant patients were cloned and sequenced. HHV-8 DNA sequences were detected in 36 of 56 (64%) normal children, in 12 of 15 (80%) healthy adults, and in all 10 renal transplant patients by Southern blot hybridization of PCR-amplified products. Six PCR-amplified products were confirmed by sequencing. These results suggest that HHV-8 infection is prevalent in the Japanese population with infection occurring in early childhood.  相似文献   
89.
One of the challenges in understanding ciliary and flagellar motility is determining the mechanisms that locally regulate dynein-driven microtubule sliding. Our recent studies demonstrated that microtubule sliding, in Chlamydomonas flagella, is regulated by phosphorylation. However, the regulatory proteins remain unknown. Here we identify the 138-kD intermediate chain of inner arm dynein I1 as the critical phosphoprotein required for regulation of motility. This conclusion is founded on the results of three different experimental approaches. First, genetic analysis and functional assays revealed that regulation of microtubule sliding, by phosphorylation, requires inner arm dynein I1. Second, in vitro phosphorylation indicated the 138-kD intermediate chain of I1 is the only phosphorylated subunit. Third, in vitro reconstitution demonstrated that phosphorylation and dephosphorylation of the 138-kD intermediate chain inhibits and restores wild-type microtubule sliding, respectively. We conclude that change in phosphorylation of the 138-kD intermediate chain of I1 regulates dynein-driven microtubule sliding. Moreover, based on these and other data, we predict that regulation of I1 activity is involved in modulation of flagellar waveform.  相似文献   
90.
PURPOSE: Anesthetics can alter the biodistribution profile of drugs and, consequently, the regional pharmacokinetics of antineoplastic drugs at the tumor site. The effect of coadministered anesthetics on the biodistribution profile of carboplatin was studied in rats. METHODS: Female Wistar rats were used to compare the effects of ketamine/xylazine, thiopental and pentobarbital on the biodistribution of 30 mg/kg radiolabelled 195mPt-carboplatin administered intravenously, with conscious rats as the control group. Blood and urine samples were collected between 5 and 120 min. RESULTS: The percentage values of the injected dose of platinum per ml (%ID/ml) in plasma at the final time-point were respectively, 0.557%, 0.156%, 0.115% and 0.086%, in pentobarbital-, ketamine/xylazine- and thiopental-injected rats, and in conscious animals. Following the same sequence of groups, the %ID/ml values of platinum in the cumulative urine were 0.001%, 0.619%, 0.184% and 0.118%, respectively. Urine output varied from very little in the pentobarbital group, to several milliliters in the other groups. CONCLUSIONS: There was an increase of almost 100-fold in total platinum uptake in the kidneys, cerebrum and cerebellum of rats receiving pentobarbital over the uptake in the control rats, whereas the biodistribution profile of the thiopental group had the least variance. These results demonstrate the importance of anesthetic selection in animal pharmacokinetic studies, as it influences the biodistribution and pharmacokinetic profile of the drug being studied.  相似文献   
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