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Age-dependent Variations (age-dependent + variation)
Selected AbstractsAge-dependent variation in the proportion and number of intestinal lymphocyte subsets, especially natural killer T cells, double-positive CD4+ CD8+ cells and B220+ T cells, in miceIMMUNOLOGY, Issue 3 2004Yuiko Ishimoto Summary The age-dependent variation in the proportion and number of lymphocyte subsets was examined at various extrathymic sites, including the liver, small intestine, colon and appendix in mice. In comparison with young mice (4 weeks of age), the number of total lymphocytes yielded by all tested organs was greater in adult (9 weeks) and old (40 weeks) mice. The major lymphocyte subset that expanded with age was interleukin-2 receptor (IL-2R) ,+ CD3int cells (50% of them expressed NK1.1) in the liver, whereas it was CD3+ IL-2R,, NK1.1, cells at all intraepithelial sites in the intestine. Although NK1.1+ CD3+ cells were present at intraepithelial sites in the intestine, the proportion of this subset was rather low. The ratio of CD4 to CD8 tended to decrease among natural killer T (NKT) cells and T cells at all intraepithelial sites in the intestine with age. A unique population of double-positive CD4+ CD8+ cells in the small intestine increased in old mice. B220+ T cells were found mainly in the appendix and colon, and the proportion of these T cells decreased in old mice. Conventional NKT cells were very few in J,281,/, and CD1d,/, mice in the liver, while NKT cells which existed in the appendix remained unchanged even in these mice. This was because unconventional CD8+ NKT cells were present in the intestine. The present results suggest that despite the fact that both the liver and intraepithelial sites in the intestine carry many extrathymic T cells, the distribution of lymphocyte subsets and their age-associated variation are site-specific. [source] Age-dependent variations of cell response to oxidative stress: Proteomic approach to protein expression and phosphorylationELECTROPHORESIS, Issue 14 2005Yuri Miura Dr. Abstract We investigated the protein profiles of variously aged rat astrocytes in response to oxidative stress. After H2O2 -exposure of cells at 100,µM for 30,min, the relative intensity of ten protein spots changed on two-dimensional (2-D) gels compared with control gels after silver staining. Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) analysis after in-gel digestion revealed that six of these spots corresponded to three kinds of proteins, each of which was composed of a protein and its modified form with a different isoelectric point (pI). These three proteins were identified as peroxiredoxins (PRDXs) II and III, and calpactin I light chain (p11). H2O2 -exposure increased the intensity of the spot with lower pI and simultaneously decreased that of the spot with higher pI for both PRDXs II and III. In addition, the expression of annexin VII, S -adenosyl- L -homocysteine hydrolase, elongation factor II fragment (EF-II), and adenosine deaminase was increased by H2O2 -exposure in astrocytes from variously aged rats. Using the Pro-Q® Diamond staining, heat shock protein 60,kDa (Hsp 60) and ,-tubulin were observed to be phosphorylated upon H2O2 -exposure. While phosphorylation of ,-tubulin was correlated positively with age, the changes in abundance of ten protein spots as described above were independent of age. These results suggest that aging does not suppress the responses aimed at limiting injury and promoting repair brought about by severe oxidative stress, and might affect cell dynamics including the formation of microtubules. [source] THE EFFECTS OF GENOTYPE, AGE, AND SOCIAL ENVIRONMENT ON MALE ORNAMENTATION, MATING BEHAVIOR, AND ATTRACTIVENESSEVOLUTION, Issue 11 2005Lisa K. Miller Abstract The traits thought to advertise genetic quality are often highly susceptible to environmental variation and prone to change with age. These factors may either undermine or reinforce the potential for advertisement traits to signal quality depending on the magnitude of age-dependent expression, environmental variation, and genotype-age and genotype-environment interaction. Measurements of the magnitude of these effects are thus a necessary step toward assessing the implications of age dependence and environmental variability for the evolution of signals of quality. We conducted a longitudinal study of male guppies (Poecilia reticulata) from 22 full-sibling families. Each fish was assigned at maturity to one of three treatments in order to manipulate his allocation of resources to reproduction: a control in which the male was kept alone, a courtship-only treatment in which he could see and court a female across a clear partition, and a mating treatment in which he interacted freely with a female. We measured each male's size, ornamental color patterns, courtship, attractiveness to females, and mating success at three ages. Size was influenced by treatment and age-treatment interactions, indicating that courtship and mating may impose costs on growth. Tail size and color patterns were influenced by age but not by treatment, suggesting fixed age-dependent trajectories in these advertisement traits. By contrast, display rate and attempted sneak copulation rate differed among treatments but not among ages, suggesting greater plasticity of these behavioral traits. As a result of the different patterns of variation in ornamentation and behavior, male attractiveness and mating success responded to male age, treatment, and the interaction between age and treatment. Neither age nor treatment obscured the presence of genetic variation, and the genetic relationship between male ornamentation and attractiveness remained the same among treatments. Our findings suggest that neither age-dependent variation nor environmentally induced variation in reproductive effort is likely to undermine the reliability of male signaling. [source] Age-related plasma reference ranges for two heparin-binding proteins , vitronectin and platelet factor 4INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 6 2009F. NEWALL Summary This study was conducted to establish age-related reference ranges for two heparin-binding proteins , vitronectin and platelet factor 4 (PF4) , and to determine if the quantitative values of these proteins may contribute to the reported age-dependent effect of unfractionated heparin (UFH). Plasma samples were obtained from healthy children aged between 1 month and 16 years and from healthy adult volunteers. Two commercial kits were used to measure plasma vitronectin and PF4 levels. Results were reported as mean and boundaries including 95% of the population. Plasma vitronectin levels for children aged 1,5 years were significantly higher compared with adults. Plasma PF4 levels for infants <1 year of age were significantly lower compared with adults. The differences between reference values for both proteins in all other age-groups were not statistically significant. This study for the first time has established age-related reference ranges for vitronectin and PF4. In establishing these ranges, the quantitative values of these proteins do not appear to be the major contributory cause for the age-dependent variation in UFH effect. Future studies are required to evaluate the possible impact of age-dependent differences in binding between heparin-binding proteins and UFH. [source] Vitamin D receptor distribution in intestines of domesticated sheep Ovis ammon f. ariesJOURNAL OF MORPHOLOGY, Issue 2 2008Katharina Riner Abstract The biologically active form of vitamin D, i.e., 1,25-dihydroxycholecalciferol or calcitriol, plays an important role in bone metabolism and calcium homeostasis, which is often disturbed at the onset of lactation in high milk-yielding domestic ruminants. Gene transcription is modulated via vitamin D receptors, but nongenomic effects of vitamin D via membrane receptors have also been described. In the intestines, vitamin D promotes calcium absorption via vitamin D receptors. Vitamin D receptors are of clinical relevance, but have not been systematically assessed within all segments of the intestine in any species. Thus, we present for the first time an immunohistochemical study of the distribution patterns of the vitamin D receptor protein in sheep, which may be the basis for present and future investigations on mineral homeostasis in domestic ruminants. Tissue probes of the intestines were collected from five lambs and five nonlactating and nonpregnant dams, fixed in formalin, embedded in paraffin, and used for the assessment of vitamin D receptor protein. Nuclear vitamin D receptor immunoreaction was scored semiquantitatively and exhibited a segment-specific distribution pattern. Goblet cells always were devoid of any vitamin D receptor immunoreaction. Surface epithelial cells and enterocytes of the crypt openings generally demonstrated only a weak immunoreaction. Basally and/or intermediately located crypt epithelial cells exhibited stronger immunoreactions in duodenum, jejunum, and colon descendens. This basal/intermediate to superficial gradient was most pronounced in the duodenum and less evident in jejunum and colon descendens and not observed in ileum and cecum. There were no age-dependent variations in vitamin D receptor protein expression. Results demonstrate that intestinal vitamin D receptor distribution patterns are segment-specific and strongest immunoreactions correlate with highest intestinal calcium absorptive activities, as reported in literature. Strong expression of vitamin D receptors within the lower half of crypts also suggests a role for calcitriol in epithelial differentiation and cellular homeostasis. J. Morphol., 2008. © 2007 Wiley-Liss, Inc. [source] Age-dependent changes in the nervous and endocrine control of the thymusMICROSCOPY RESEARCH AND TECHNIQUE, Issue 2 2004Jonas Hannestad Abstract The immune system, especially the thymus, undergoes age-related modifications leading to structural and functional changes in the lymphoid organs and immunocompetent cells. Nevertheless, the consequences of thymic involution in the peripheral pool of T-cells are still a matter of controversy. The control of the thymic function is very complex and involves intrathymic signals, the autonomic nervous system, and the endocrine system. Both thymocytes and thymic stromal cells express receptors for a wide range of hormones, as well as for neurotransmitters and neuropeptides, thus affecting thymocytes maturation. This review summarizes the age-dependent variations in the extrathymic components of the thymic microenvironment, i.e., vegetative nerves and hormones, and the possible effects of those changes in the immune function. Microsc. Res. Tech. 63:94,101, 2004. © 2004 Wiley-Liss, Inc. [source] Levels of soluble CD30 in cord blood and peripheral blood during childhood are not correlated with the development of atopic disease or a family history of atopyCLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2003U. Holmlund Summary Background The CD30 molecule has been linked to Th2 responses. Furthermore, elevated levels of the soluble form of CD30 (sCD30) in blood as well as of the expression of CD30 on the plasma membrane of T cells are associated with atopic disease. Objective To assess the potential usefulness of sCD30 levels as a prognostic indicator of and/or diagnostic marker for the development of atopic disease in children. Methods sCD30 levels in cord blood and peripheral blood from 36 2-year-old (10 atopic and 26 non-atopic) and 74 7-year-old (35 atopic and 39 non-atopic) children were determined employing an ELISA procedure. Atopy was diagnosed on the basis of clinical evaluation in combination with a positive skin prick test. Results No significant correlation between sCD30 levels in cord blood and the development of atopic disease at 2 or 7 years of age was observed. At 7 years of age, the circulating sCD30 levels in children with atopic disease (median 41 U/mL, range 6,503 U/mL) did not differ from the corresponding values for non-atopic subjects (median 41 U/mL, range 8,402 U/mL). The same was true for children at 2 years of age. Furthermore, the sCD30 levels of children who had developed atopic eczema/dermatitis syndrome by the age of 7 years (median 49 U/mL, range 14,503 U/mL) were not significantly elevated in comparison with those of the non-atopic children. Finally, neither sCD30 levels in cord blood nor peripheral blood at 2 or 7 years of age could be linked to a family history of atopy. Conclusion These findings indicate that the sCD30 concentration in cord blood is not a reliable prognostic indicator of, nor a useful diagnostic marker for, atopic disease in children up to 7 years of age. If such correlations do exist, they might be masked by age-dependent variations in the circulating levels of sCD30, which may reflect individual differences in the maturation of children's immunological responses. [source] | |||||||||||||