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61.
At older ages, the circadian rhythm of body temperature shows a decreased amplitude, an advanced phase, and decreased stability. The present review evaluates to what extent these changes may result from age-related deficiencies at several levels of the thermoregulatory system, including thermoreception, thermogenesis and conservation, heat loss, and central regulation. Whereas some changes are related to the aging process per se, others appear to be secondary to other factors, for which the risk increases with aging, notably a decreased level of fitness and physical activity. Moreover, functional implications of the body temperature rhythm are discussed. For example, the relation between circadian rhythm and thermoregulation has hardly been investigated, while evidence showed that sleep quality is dependent on both aspects. It is proposed that the circadian rhythm in temperature in homeotherms should not be regarded as a leftover of ectothermy in early evolution, but appears to be of functional significance for physiology from the level of molecules to cognition. A new view on the functional significance of the circadian rhythm in peripheral vasodilation and the consequent out-of-phase rhythms in skin and core temperature is presented. It is unlikely that the strong, daily occurring, peripheral vasodilation primarily represents heat loss in response to a lowering of set point, since behavioral measures are simultaneously taken in order to prevent heat loss. Several indications rather point towards a supportive role in immunological host defense mechanisms. Given the functional significance of the temperature rhythm, research should focus on the feasibility and effectiveness of methods that can in principle be applied in order to enhance the weakened circadian temperature rhythm in the elderly. 相似文献
62.
Voxel-based lesion-symptom mapping 总被引:5,自引:0,他引:5
Bates E Wilson SM Saygin AP Dick F Sereno MI Knight RT Dronkers NF 《Nature neuroscience》2003,6(5):448-450
63.
Molecular typing of Mycobacterium tuberculosis by mycobacterial interspersed repetitive unit-variable-number tandem repeat analysis, a more accurate method for identifying epidemiological links between patients with tuberculosis
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van Deutekom H Supply P de Haas PE Willery E Hoijng SP Locht C Coutinho RA van Soolingen D 《Journal of clinical microbiology》2005,43(9):4473-4479
IS6110 fingerprinting of Mycobacterium tuberculosis is the standard identification method in studies on transmission of tuberculosis. However, intensive epidemiological investigation may fail to confirm transmission links between patients clustered by IS6110-restriction fragment length polymorphism (RFLP) typing. We applied typing based on variable numbers of tandem repeats (VNTRs) of mycobacterial interspersed repetitive units (MIRUs) to isolates from 125 patients in 42 IS6110 clusters, for which thorough epidemiological data were available, to investigate the potential of this method in distinguishing epidemiologically linked from nonlinked patients. Of seven IS6110 clusters without epidemiological links, five were split by MIRU-VNTR typing, while nearly all IS6110 clusters with proven or likely links displayed conserved MIRU-VNTR types. These results provide molecular evidence that not all clusters determined on the basis of multibanded IS6110 RFLP patterns necessarily reflect transmission of tuberculosis. They support the use of MIRU-VNTR typing as a more reliable and faster method for transmission analysis. 相似文献
64.
The P-selectin gene is highly polymorphic: reduced frequency of the Pro715 allele carriers in patients with myocardial infarction 总被引:10,自引:3,他引:10
Herrmann SM; Ricard S; Nicaud V; Mallet C; Evans A; Ruidavets JB; Arveiler D; Luc G; Cambien F 《Human molecular genetics》1998,7(8):1277-1284
P-selectin is an adhesion molecule, expressed at the surface of activated
cells, that mediates the interaction of activated endothelial cells or
platelets with leukocytes. P-selectin expression is increased in
atherosclerotic plaques, and high plasma levels of this molecule have been
observed in patients with unstable angina. We investigated the P-selectin
gene as a possible candidate for myocardial infarction (MI). The P-selectin
gene is situated on chromosome 1q21-q24, spans >50 kb and contains 17
exons. The sequences of the 5'-flanking region and exons of 40 alleles from
patients with MI were screened for polymorphisms using polymerase chain
reaction/single-strand conformation polymorphism (PCR-SSCP) and sequencing.
Thirteen polymorphisms were identified: five in the 5'-flanking and eight
in the exonic sequences. Four polymorphisms (Ser290Asn, Asn562Asp,
Leu599Val and Thr715Pro) predicted a change in the amino acid sequence of
the P- selectin protein. All P-selectin polymorphisms as well as a common
E- selectin polymorphism, Ser128Arg which has been reported as being
associated with an increased risk of premature coronary heart disease
(CHD), and is in tight linkage disequilibrium with several P-selectin
polymorphisms, were investigated in 647 patients with MI and 758 control
subjects from four regions of France and Northern Ireland (the ECTIM
study). The entire set of P-selectin polymorphisms provided a
heterozygosity of 91%. The polymorphisms were tightly associated with one
another and displayed patterns of linkage disequilibrium suggesting the
existence of highly conserved ancestral haplotypes. The five polymorphisms
in the 5'-flanking region of the gene were unrelated to MI or any relevant
phenotype measured in the ECTIM study. We inferred that the four missense
variants identified in the coding region predicted eight common forms of
the P-selectin protein. The Pro715 allele which characterizes one of these
forms was less frequent in France than in Northern Ireland ( P < 0.002)
and in cases than in controls ( P < 0.002; P < 0.02 after correction
for the number of tests). We conclude that the P-selectin gene is highly
polymorphic and hypothesize that the Pro715 variant may be protective for
MI. Whether this variant affects the properties of the P-selectin protein
in a way which is compatible with this hypothesis needs to be checked
experimentally.
相似文献
65.
Sperm quality in Hodgkin's disease versus non-Hodgkin's lymphoma 总被引:3,自引:4,他引:3
Botchan A; Hauser R; Gamzu R; Yogev L; Lessing JB; Paz G; Yavetz H 《Human reproduction (Oxford, England)》1997,12(1):73-76
The study was conducted to determine the deleterious effect of lymphoma
disease on spermatogenesis and to evaluate the possibility that the disease
is mediated primarily by inherent mechanisms in Hodgkin's disease and
non-Hodgkin's lymphoma patients. A total of 89 patients with lymphoma
disease (Hodgkin's and non-Hodgkin's) were referred for sperm preservation
prior to adjuvant treatments. A comparison was made of pre- and post-thaw
sperm quality between lymphoma patients and healthy volunteers who applied
for sperm donation. This was followed by further assessment of the
differences between patients with Hodgkin's disease and non-Hodgkin's
lymphoma in terms of sperm variables, clinical parameters and blood hormone
concentrations. It was found that patients with lymphoma disease had
significantly impaired pre-freeze and post-thaw sperm quality compared with
that of healthy volunteers. Patients with non-Hodgkin's lymphoma had
spermatozoa of higher quality than patients with Hodgkin's disease. No
differences were found in the clinical or hormonal parameters between these
two groups. As expected, reduced testicular size and abnormal testicular
consistency were correlated with decreased sperm quality. The mere presence
of cancer disease has a direct negative effect on spermatogenesis, which is
probably not related to incidental side-effects. A variable degree of
impairment should be expected with different categories of cancer.
相似文献
66.
67.
Effect of influenza A virus on leukocyte histamine release 总被引:5,自引:0,他引:5
W W Busse C A Swenson E C Borden M W Treuhaft E C Dick 《The Journal of allergy and clinical immunology》1983,71(4):382-388
Viral respiratory infections provoke asthma in many patients. In the following study we examined the effect of an in vitro incubation of influenza A on leukocyte histamine release. After incubation with a live influenza A (H3N2) virus, calcium ionophore A23187 (0.5, 1.0, and 1.5 microgram/ml)-induced leukocyte histamine release (HR) was enhanced (p less than 0.05). This effect was also found with heat- or ether-inactivated virus. Similarly, influenza A-exposed leukocytes had augmented leukocyte HR during subsequent incubation with ragweed AgE. Incubation of the leukocyte suspension with interferon (800 IU/ml) for 24 hr was also associated with enhanced HR to ragweed AgE. In contrast, interferon did not alter the calcium ionophore A23187 HR. Therefore, although interferon may mediate the enhanced leukocyte HR when ragweed AgE is the inciting stimulus, it does not change HR to the calcium ionophore. 相似文献
68.
Practical aspects of functional MRI (NMR Task Group #8) 总被引:1,自引:0,他引:1
Price RR Allison J Massoth RJ Clarke GD Drost DJ;NMR Task Group # 《Medical physics》2002,29(8):1892-1912
69.
Prediction of clinical course of bipolar manic depressive illness treated with lithium 总被引:1,自引:0,他引:1
A group of bipolar manic depressive patients attending a routine lithium clinic were investigated. The results suggest that, when on treatment with lithium, manic depressive patients with a good prognosis tend to have a higher erythrocyte Na-K ATPase and higher plasma and erythrocyte lithium concentrations than those with a poor prognosis. There was no evidence to suggest that the erythrocyte: plasma lithium ratio was useful in predicting clinical response to lithium therapy. There was also a positive correlation between plasma lithium concentration and Na-K ATPase activity, confirming that in manic depressive subjects lithium produces a rise in erythrocyte Na-K ATPase activity. 相似文献
70.
Summary The characteristics of two clinical isolates of HSV-1 obtained from an oral (424) and an anal (490) lesion were compared with the highly passaged KOS strain. In contrast to KOS, the clinical isolates produced small plaques, were more cell-associated and the predominant viral glycoprotein species for gC and gD in infected cell lysates was the precursor, high mannose glycoform. Total virus production in Vero cells was equivalent for the three virus strains in one-step growths. Pulse-chase studies of glycoprotein C processing showed a reduction in rate at 7.5h post infection and a significant block in processing at 10.5h post infection for 424 and 490 but not KOS. Similar results were obtained for gD. The significant reduction in glycoprotein processing for 424 and 490 suggests a block in transport of viral glycoproteins or virions to and through the Golgi apparatus. Extracellular virions and the cell surface, prior to cell lysis, contained the processed gC glycoform suggesting a competent cellular glycan processing system. Upon co-infection of 424 or 490 with KOS or a gC– KOS strain, gC was processed to levels equivalent to KOS indicating that 424 and 490 are not inhibitory but that an activity(s) encoded by KOS facilitates maturation of gC from 424 and 490. Unlike KOS infected Vero cells, virion-containing vacuoles were observed in the cytoplasm at 12h p.i. and extracellular virions were concentrated at cell-cell junctions of 424 or 490 infected cells but not in the perinuclear region. These results suggest that intracellular transport of viral glycoproteins and virions in 424 and 490 infected cells is different from KOS infected cells. The reduced level of viral glycoprotein maturation, virus release, cell surface presence and presence of virions at cell-cell junctions are consistent with small plaque production in tissue culture cells.Portions of this work were presented in the 17th International Herpesvirus Workshop, Pittsburgh, PA, 1993. 相似文献