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排序方式: 共有206条查询结果,搜索用时 343 毫秒
51.
Camila Vieira Ligo Teixeira Thiago JR Rezende Marina Weiler Mateus H Nogueira Brunno M Campos Luiz FL Pegoraro Jessica E Vicentini Gabriela Scriptore Fernando Cendes Marcio LF Balthazar 《Age (Dordrecht, Netherlands)》2016,38(3):51
Mild cognitive impairment (aMCI) is a clinical condition, with high risk to develop Alzheimer’s disease. Physical exercise may have positive effect on cognition and brain structure in older adults. However, it is still under research whether these influences are true on aMCI subjects with low Ab_42 and high total tau in cerebrospinal fluid (CSF), which is considered a biomarker for AD. Therefore, we aimed to investigate a possible relation between aerobic fitness (AF) and gray matter (GM) volume and AF and white matter (WM) integrity in aMCI with a CSF biomarker. Twenty-two participants with aMCI acquired the images on a 3.0-T MRI. AF was assessed by a graded exercise test on a treadmill. Voxel-based morphometry and tract-based spatial statistic methods were used to analyze the GM volume and WM microstructural integrity, respectively. We correlated AF and GM volume and WM integrity in aMCI (p < 0.05, FWE corrected, cluster with at least five voxels). There was a positive relation between AF and GM volume mostly in frontal superior cortex. In WM integrity, AF was positively correlated with fractional anisotropy and negatively correlated with mean diffusivity and radial diffusivity, all in the same tracts that interconnect frontal, temporal, parietal, and occipital areas (longitudinal fasciculus, fronto-occipital fasciculus, and corpus callosum). These results suggest that aerobic fitness may have a positive influence on protection of brain even in aMCI CSF biomarker, a high-risk population to convert to AD. 相似文献
52.
Background
Imprisonment may lead to the development of mental illness, especially depression. This study examines the clinical and sociodemographic profiles of imprisoned women, identifies indicative signs of depression, and relates these indicators to other variables. 相似文献53.
Cystatin C and carotid intima-media thickness in asymptomatic adults: the Multi-Ethnic Study of Atherosclerosis (MESA) 总被引:1,自引:0,他引:1
AL Bui R Katz B Kestenbaum IH de Boer LF Fried JF Polak BA Wasserman MJ Sarnak D Siscovick MG Shlipak 《American journal of kidney diseases》2009,53(3):389-398
BACKGROUND: Persons with early kidney disease have an increased risk of cardiovascular events and mortality, but the importance of accelerated atherosclerosis in promoting these outcomes is unclear. We therefore explored whether serum cystatin C level is associated with carotid intima-media thickness (IMT) in ambulatory adults without clinical heart disease. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: We evaluated 6,557 ethnically diverse persons free of clinical cardiovascular disease aged 45 to 84 years at the baseline visit of the Multi-Ethnic Study of Atherosclerosis. PREDICTORS: Kidney function was estimated by using 2 methods: serum cystatin C level and estimated glomerular filtration rate, based on creatinine and cystatin C levels. OUTCOMES & MEASUREMENTS: Study outcomes were internal and common carotid IMT, measured by using high-resolution B-mode ultrasound. Multivariate linear and logistic regressions were used to evaluate the independent association of kidney function with carotid IMT. RESULTS: In unadjusted linear analysis, each SD (0.23 mg/L) greater cystatin C level was associated with 0.091-mm greater internal carotid IMT (P < 0.001), but this association was diminished by 70% after adjustment for age, sex, and race/ethnicity (0.027 mm; P < 0.001) and was no longer significant after adjustment for cardiovascular risk factors (0.005 mm; P = 0.5). Similarly, the strong unadjusted associations of cystatin C level with common carotid IMT disappeared after adjustment. Chronic kidney disease, defined by using either creatinine level or cystatin C-based estimated glomerular filtration rate less than 60 mL/min/1.73 m(2), had no independent association with internal and common carotid IMT. LIMITATIONS: There were few participants with severe kidney disease. CONCLUSIONS: Cystatin C level had no independent association with carotid IMT in a population free of clinical heart disease. This observation suggests that accelerated atherosclerosis is unlikely to be the primary mechanism explaining the independent association of cystatin C level with cardiovascular risk. 相似文献
54.
55.
Xu M; Schut HA; Bjeldanes LF; Williams DE; Bailey GS; Dashwood RH 《Carcinogenesis》1997,18(11):2149-2153
Indole-3-carbinol (I3C) inhibits the formation of colonic aberrant crypt
foci and DNA adducts in rats given heterocyclic amine colon carcinogens,
such as 2-amino-3-methylimidazo[4,5-f]quinoline (IQ). Mechanism studies
indicate that I3C induces cytochromes P4501A1 and 1A2 (CYP1A1 and CYP1A2),
isozymes that respectively metabolize IQ via ring hydroxylation or activate
the carcinogen by N-hydroxylation. The present study examined the
dose-response for induction of CYP1A1 versus CYP1A2 by I3C, and compared
the profiles of induction with the dose- response for inhibition of IQ-DNA
adducts in the colon of the F344 rat. Dietary equivalent doses of I3C in
the range 100-1000 p.p.m. increased in a dose-related manner both
ethoxyresorufin O-deethylase (EROD) and methoxyresorufin O-demethylase
(MROD) activities in the liver and colonic mucosa, and Western blots showed
a corresponding induction of CYP1A1 and CYP1A2 proteins. However, dietary
equivalent doses of I3C in the range 10-25 p.p.m. (i) reduced hepatic EROD
and MROD activities and CYP1A protein levels compared with controls, (ii)
increased the ratio of CYP1A2 versus CYP1A1, and (iii) activated IQ to a
more potent mutagen when liver microsomes from rats given I3C were used for
metabolic activation in the Salmonella assay. Rats given a single oral dose
of I3C shortly before administering IQ (5 mg/kg body wt, p.o.) exhibited
dose-related inhibition of colonic IQ-DNA adducts in the range 25-100
p.p.m. I3C, reaching 95% inhibition at doses > or = 100 p.p.m. I3C, but
IQ-DNA adducts were elevated slightly at the lowest I3C dose as compared
with the controls. The possible significance of the low versus high dose
effects of I3C are discussed in the context of human dietary exposures to
I3C and the reported chemopreventive mechanisms of I3C in vivo.
相似文献
56.
Deletion/insertion mutation that causes biotinidase deficiency may result from the formation of a quasipalindromic structure 总被引:2,自引:0,他引:2
Pomponio RJ; Narasimhan V; Reynolds TR; Buck GA; Povirk LF; Wolf B 《Human molecular genetics》1996,5(10):1657-1661
Biotinidase is responsible for recycling the vitamin biotin from biocytin
that is formed after the proteolytic degradation of the biotin- dependent
carboxylases. We have identified a deletion/insertion mutation within exon
D of the human biotinidase gene in a child with biotinidase deficiency. The
mutation causes a frame shift and premature termination which are predicted
to result in a truncated protein. We propose that the mutation occurred
during DNA replication by either of two mechanisms. Both mechanisms involve
formation of a quasipalindromic hairpin loop in the template and
dissociation of DNA polymerase alpha. This mutation supports the formation
of palindromic structures as a possible cause of deletions in eukaryotes,
and supports the proposal, derived from in vitro studies, that polymerase
alpha may preferentially arrest or dissociate at specific template
sequences.
相似文献
57.
58.
二苯乙烯类化合物对蛋白激酶C的抑制作用 总被引:14,自引:0,他引:14
报道15种二苯乙烯类化合物对蛋白激酶C(PKC)活性的影响。其中从中药金雀根中分得的3种二苯乙烯类低聚体α-viniferin,kobophenol A 和 miyabenolC,它们抑制PKC的IC50分别为62.5,52.0和27.5μmol·L-1。另外6种含酚羟基的二苯乙烯化合物对PKC也显示不同程度的抑制作用,但当酚羟基全甲基化或全乙酰化后其抑制作用大大降低甚至消失。酶动力学研究证明miyabenolC对PKC的抑制作用属于非竞争性抑制。 相似文献
59.
Eplov LF Jørgensen T Birket-Smith M Segel S Johansen C Mortensen EL 《Epidemiology (Cambridge, Mass.)》2005,16(2):226-232
BACKGROUND: Studies have demonstrated that mental vulnerability (ie, a tendency to experience psychosomatic symptoms or inadequate interpersonal interactions) is associated with various diseases. The objective of our study is to evaluate whether mental vulnerability is a risk factor for early mortality. METHODS: We conducted a prospective cohort study of 3 random samples of the population in Copenhagen County, Denmark selected in 1976, 1982-1984, and 1991 (n = 6435). Baseline data collection included measures of mental vulnerability, social factors, comorbidity, biologic risk markers (eg, blood pressure, lipid levels), and lifestyle factors. We determined vital status of the study sample through linkage to the Civil Registration System until 2001 and to the Cause of Death Registry until 1998. The mean follow-up time was 15.9 years for analysis of total mortality and 13.6 years for analysis of mortality as the result of natural causes. The association between mental vulnerability and survival was examined using Kaplan-Meir plots and Cox proportional-hazard models adjusting for possible confounding factors. RESULTS: With respect to mental vulnerability, 79% of the sample was classified as not vulnerable, 13% as moderately vulnerable, and 8% as highly vulnerable. Compared with the nonvulnerable group, highly vulnerable persons showed increased total mortality (hazard ratio = 1.6; 95% confidence interval = 1.3-1.9) and increased mortality from natural causes (1.6; 1.2-2.0). The inclusion of the mental vulnerability score as a continuous variable gave similar results. CONCLUSIONS: Mental vulnerability may be an independent risk factor for premature mortality. The biologic mechanisms that may underlie this association need further exploration. 相似文献
60.