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41.
JT Marais 《Canadian Metallurgical Quarterly》1998,53(3):111-119
The Mini-Mental-State Examination (MMSE) is widely used as a screening tool for dementia in epidemiological studies. Its applicability in population-based studies is nevertheless limited by its low specificity. The effect of age and educational level have been usually ignored when cut-off scores have been selected. The aim of this study was to evaluate the effect of age and educational level on the MMSE scores in a representative sample of subjects older than 70 and provide adjusted normalised data according to these two variables, after excluding subjects with dementia or cognitive decline. Population-based, cross-sectional and longitudinal study of a representative cohort of 1367 subjects older than 70. All subjects with suspected dementia or cognitive decline received a neurological evaluation where clinical and etiological diagnosis were established. Normal MMSE scores, as defined by the 10th percentile, varied significantly across age and educational level groups. Exclusion of demented or cognitively declined patients from the reference population reduced the variability and "range of normality", but this remained excessively high in the older and less educated groups. The use of different cut-off points for each age and educational level groups may improve the specificity and applicability of the MMSE in population-based epidemiological studies. However, the wide amplitude of the range of normality suggests that different approaches, other than this vibariate analysis, may prove more adequate in the selection of cut-off scores for the MMSE. 相似文献
42.
P So JT Francis TI Netoff BJ Gluckman SJ Schiff 《Canadian Metallurgical Quarterly》1998,74(6):2776-2785
A new nonlinear dynamical analysis is applied to complex behavior from neuronal systems. The conceptual foundation of this analysis is the abstraction of observed neuronal activities into a dynamical landscape characterized by a hierarchy of "unstable periodic orbits" (UPOs). UPOs are rigorously identified in data sets representative of three different levels of organization in mammalian brain. An analysis based on UPOs affords a novel alternative method of decoding, predicting, and controlling these neuronal systems. 相似文献
43.
JW Lynch GA Kaplan RD Cohen J Tuomilehto JT Salonen 《Canadian Metallurgical Quarterly》1996,144(10):934-942
Much remains to be understood about how low socioeconomic status (SES) increases cardiovascular disease and mortality risk. Data from the Kuopio Ischemic Heart Disease Risk Factor Study (1984-1993) were used to estimate the associations between acute myocardial infarction and income, all-cause mortality, and cardiovascular mortality in a population-based sample of 2,272 Finnish men, with adjustment for 23 biologic, behavioral, psychologic, and social risk factors. Compared with the highest income quintile, those in the bottom quintile had age-adjusted relative hazards of 3.14 (95% confidence interval (CI) 1.77-5.56), 2.66 (95% CI 1.25-5.66), and 4.34 (95% CI 1.95-9.66) for all-cause mortality, cardiovascular mortality, and AMI, respectively. After adjustment for risk factors, the relative hazards for the same comparisons were 1.32 (95% CI 0.70-2.49), 0.70 (95% CI 0.29-1.69), and 2.83 (95% CI 1.14-7.00). In the lowest income quintile, adjustment for risk factors reduced the excess relative risk of all-cause mortality by 85%, that of cardiovascular mortality by 118%, and that of acute myocardial infarction by 45%. These data show how the association between SES and cardiovascular mortality and all-cause mortality is mediated by known risk factor pathways, but full "explanations" for these associations will need to encompass why these biologic, behavioral, psychologic, and social risk factors are differentially distributed by SES. 相似文献
44.
We studied the effect of short-term triiodothyronine administration on thyroid gland responsivity to exogenous thyrotropin in four euthyroid human subjects. Thyroidal iodine release and serum thyroxine during daily im injections of bovine TSH were not significantly inhibited, despite a four-fold elevation in serum T3 concentrations. This negative finding contrasts with earlier positive reports of a regulatory "short-loop" effect of elevated circulating T3 on the thyroid gland. This difference may be due either to the use in previous murine or in vitro studies of non-physiologic, high doses of exogenous T3, or failure to control the withdrawal of the trophic effect of endogenous TSH in man on the subsequent glandular response. 相似文献
45.
Myocardial biopsies from two patients who had developed "stone heart" (myocardial rigor mortis; ischemic contracture of the left ventricle) were studied by electron microscopy. The ultrastructure of tissue in stone heart, though ischemic in nature, differed from that of classic myocardial infarction in some respects. Apart from depletion of glycogen and distension of the sarcoplasmic reticulum and T-tubules, myofibrillar degeneration was much more widespread. Mitochondrial degeneration with active lysosomal autodigestion, disruption of the microcirculation, and lymphedema were prominent changes also observed. In the light of known clinical and experimental observations, our findings suggest that stone heart is an accelerated form of ischemic injury occurring in vulnerable (hypertrophied) hearts and is probably related to ischemia-triggered release of endogenous catecholamines. 相似文献
46.
Qianhui Lee David JT Hill Tri Le Firas Rasoul Andrew K Whittaker 《Polymer International》2009,58(4):348-353
BACKGROUND: Copolymers of acrylic acid (AA) are important materials for the preparation of glass ionomer cements. Copolymerisation of AA is widely used to alter the acid strength of the material and to increase the number of salt bridges formed in cements. In this paper we report the copolymerisation of AA with n‐butyl vinyl ether (BVE) to form unique copolymers of the hemiacetal ester and with BVE incorporated into the main chain. RESULTS: AA and BVE undergo a spontaneous reaction to form a hemiacetal ester which can itself undergo free radical copolymerisation. The kinetics of this reaction in the bulk state have been examined. In addition, under these conditions BVE is incorporated into the polymer main chain via a free radical mechanism. CONCLUSION: Novel copolymers of the hemiacetal ester and BVE have been prepared in this study. The hemiacetal side chains are labile under moderate heating, being converted back to the acid analogue. Copyright © 2009 Society of Chemical Industry 相似文献
47.
HI McFarland AA Lobito MM Johnson JT Nyswaner JA Frank GR Palardy N Tresser CP Genain JP Mueller LA Matis MJ Lenardo 《Canadian Metallurgical Quarterly》1999,162(4):2384-2390
Definition of the immune process that causes demyelination in multiple sclerosis is essential to determine the feasibility of Ag-directed immunotherapy. Using the nonhuman primate, Callithrix jacchus jacchus (common marmoset), we show that immunization with myelin basic protein and proteolipid protein determinants results in clinical disease with significant demyelination. Demyelination was associated with spreading to myelin oligodendrocyte glycoprotein (MOG) determinants that generated anti-MOG serum Abs and Ig deposition in central nervous system white matter lesions. These data associate intermolecular "determinant spreading" with clinical autoimmune disease in primates and raise important issues for the pathogenesis and treatment of multiple sclerosis. 相似文献
48.
C Liu AB Bahnson JT Dunigan SC Watkins JA Barranger 《Canadian Metallurgical Quarterly》1998,76(11):773-781
The majority of studies dealing with DNA analyses are made on fixed cells. In this context, the efficiency as fixatives of ethanol, methanol, acetone, Carnoy, Boehm-Sprenger and aldehydes was determined using two different DNA fluorescent probes, Hoechst 33342 and propidium iodide. The purpose of our study was to find the fixative that would provide the best results with respect to the following parameters: aggregates, cell size and granularity, and DNA staining analysis. Using murine fibroblasts, we found that 68% ethanol, 85% methanol and aldehydes did not increase aggregate formation, whereas Carnoy, acetone or Boehm-Sprenger fixatives did. The results show that aldehydes seem to alter cell size least. All fixatives induce an increase in cell granularity, which is very pronounced with alcohols, but aldehydes alter morphology less than alcohols. We observed that the fixatives giving the best resolution with Hoechst 33342 staining lead to a lower measurement variability than with propidium iodide staining. This study leads us to conclude that 68% ethanol and 85% methanol can be considered as appropriate fixatives for flow cytometry studies of DNA content. 相似文献
49.
DE Epner AW Partin JA Schalken JT Isaacs DS Coffey 《Canadian Metallurgical Quarterly》1993,53(9):1995-1997
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) expression is increased in Dunning R-3327 rat prostatic adenocarcinoma cell lines relative to normal rat ventral prostate tissue. GAPDH expression closely correlates with cell motility of Dunning prostate cancer cell lines and accurately distinguishes cell lines with high metastatic potential from those with low metastatic potential. Increased GAPDH expression in the cancer cell lines is not simply related to increased growth rate, since rapidly proliferating normal prostate tissue did not exhibit elevated GAPDH expression. 相似文献
50.
MA Markiewicz C Girao JT Opferman J Sun Q Hu AA Agulnik CE Bishop CB Thompson PG Ashton-Rickardt 《Canadian Metallurgical Quarterly》1998,95(6):3065-3070
How memory T cells are maintained in vivo is poorly understood. To address this problem, a male-specific peptide (H-Y) was identified and used to activate female anti-H-Y T cells in vitro. Anti-H-Y T cells survived in vivo for at least 70 days in the absence of antigen. This persistence was not because of the intrinsic ability of memory T cells to survive in vivo. Instead, the survival and function of adoptively transferred memory cells was found to require transporter of antigen protein 1-dependent expression of self-peptide/major histocompatibility complex class I molecules in recipient animals. Therefore, it appears that the level of T cell receptor engagement provided by transporter of antigen protein 1-dependent, self-peptide/major histocompatibility complexes is sufficient to maintain the long-term survival and functional phenotype of memory cells in the absence of persistent antigen. These data suggest that positive selection plays a role not only in T cell development but also in the maintenance of T cell memory. 相似文献