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排序方式: 共有64条查询结果,搜索用时 203 毫秒
1.
A novel role for interleukin 2 in antibody responses: down-regulation of T helper cell activation 总被引:1,自引:0,他引:1
This report provides new insights into the role of the T cell growth factor interleukin 2 (IL 2) for the regulation of antibody responses. Evidence is presented that IL 2 down-regulates T helper cell (Thc) activation but not Thc effector function, i.e., Thc-B cooperation. Thus, reagents which block the IL 2 pathway, e.g., cyclosporin A (CsA) or IL 2 receptor monoclonal antibodies (IL 2R Mab) enhanced Thc activation although T cell proliferation was blocked. In contrast, CsA or IL 2R Mab blocked Thc-B cooperation, suggesting that IL 2 is required for this step. The regulatory role of IL 2 was reconfirmed by the addition of exogenous IL 2 into the cultures which reversed the enhancing or blocking effect of CsA. 相似文献
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After inhibition by bis-p-nitrophenyl phosphate and subsequent staining for esterase using naphthol AS-D acetate as the substrate, a strong lysosomal esterase was demonstrated in the cauda epididymidis of mouse, rat, and man. Owing to its behaviour towards the classifying inhibitors eserine, diisopropyl fluorophosphate, bis-p-nitrophenyl phosphate, and p-chloromercuriphenylsulphonate, this lysosomal esterase was shown to be an acetylesterase (EC 3.1.1.6). Control experiments involving isoelectric focusing revealed that this acetylesterase was identical with the genetically defined homologues ES-17, ES-6, and ES-A4 in mouse, rat, and man, respectively. 相似文献
4.
Twenty-five (25) electrophoretic bands with esterase activity were distinguished in supernatants of cauda epididymidis of DBA/2J mice. Twenty (20) of these were assigned to 10 genetically defined esterases (ES-1, ES-2, ES-3, ES-6, ES-7, ES-11, ES-14, ES-17, ES-19, ES-22) which were already known from investigations of other mouse tissues. Furthermore, ES-10 was identified in cauda supernatants after isoelectric focussing. A hitherto genetically undefined esterase was assigned to locus Es-28 which was expressed solely in the epididymis. Three phenotypes were distinguished: ES-28A was present in the majority of the inbred strains examined. ES-28B was observed in AKR/Han mice and ES-28C was found in SEG/1 mice. 相似文献
5.
Kathleen M. Gorman Esther Meyer Detelina Grozeva Egidio Spinelli Amy McTague Alba Sanchis-Juan Keren J. Carss Emily Bryant Adi Reich Amy L. Schneider Ronit M. Pressler Michael A. Simpson Geoff D. Debelle Evangeline Wassmer Jenny Morton Diana Sieciechowicz Eric Jan-Kamsteeg Alex R. Paciorkowski Manju A. Kurian 《American journal of human genetics》2019,104(5):948-956
6.
Gravity and light effects on the circadian clock of a desert beetle,Trigonoscelis gigas 总被引:1,自引:0,他引:1
Hoban-Higgins TM Alpatov AM Wassmer GT Rietveld WJ Fuller CA 《Journal of insect physiology》2003,49(7):671-675
Circadian function is affected by exposure to altered ambient force environments. Under non-earth gravitational fields, both basic features of circadian rhythms and the expression of the clock responsible for these rhythms are altered. We examined the activity rhythm of the tenebrionid beetle, Trigonoscelis gigas, in conditions of microgravity (microG; spaceflight), earth's gravity (1 G) and 2 G (centrifugation). Data were recorded under a light-dark cycle (LD), constant light (LL), and constant darkness (DD). Free-running period (tau) was significantly affected by both the gravitational field and ambient light intensity. In DD, tau was longer under 2 G than under either 1 G or microG. In addition, tauLL was significantly different from tauDD under microG and 1 G, but not under 2 G. 相似文献
7.
JG Hansen W Gao J Dupuis GT O’Connor W Tang M Kowgier A Sood SA Gharib LJ Palmer M Fornage SR Heckbert BM Psaty SL Booth SUNLIGHT Consortium Patricia A Cassano 《Respiratory research》2015,16(1)
Background
Vitamin D is associated with lung function in cross-sectional studies, and vitamin D inadequacy is hypothesized to play a role in the pathogenesis of chronic obstructive pulmonary disease. Further data are needed to clarify the relation between vitamin D status, genetic variation in vitamin D metabolic genes, and cross-sectional and longitudinal changes in lung function in healthy adults.Methods
We estimated the association between serum 25-hydroxyvitamin D [25(OH)D] and cross-sectional forced expiratory volume in the first second (FEV1) in Framingham Heart Study (FHS) Offspring and Third Generation participants and the association between serum 25(OH)D and longitudinal change in FEV1 in Third Generation participants using linear mixed-effects models. Using a gene-based approach, we investigated the association between 241 SNPs in 6 select vitamin D metabolic genes in relation to longitudinal change in FEV1 in Offspring participants and pursued replication of these findings in a meta-analyzed set of 4 independent cohorts.Results
We found a positive cross-sectional association between 25(OH)D and FEV1 in FHS Offspring and Third Generation participants (P = 0.004). There was little or no association between 25(OH)D and longitudinal change in FEV1 in Third Generation participants (P = 0.97). In Offspring participants, the CYP2R1 gene, hypothesized to influence usual serum 25(OH)D status, was associated with longitudinal change in FEV1 (gene-based P < 0.05). The most significantly associated SNP from CYP2R1 had a consistent direction of association with FEV1 in the meta-analyzed set of replication cohorts, but the association did not reach statistical significance thresholds (P = 0.09).Conclusions
Serum 25(OH)D status was associated with cross-sectional FEV1, but not longitudinal change in FEV1. The inconsistent associations may be driven by differences in the groups studied. CYP2R1 demonstrated a gene-based association with longitudinal change in FEV1 and is a promising candidate gene for further studies.Electronic supplementary material
The online version of this article (doi:10.1186/s12931-015-0238-y) contains supplementary material, which is available to authorized users. 相似文献8.
ObjectivesTo evaluate the prevalence and predictors of vitamin D insufficiency (VDI) in children In Great Britain.DesignA nationally representative cross-sectional study survey of children (1102) aged 4–18 years (999 white, 570 male) living in private households (January 1997–1998). Interventions provided information about dietary habits, physical activity, socio-demographics, and blood sample. Outcome measures were vitamin D insufficiency (<50 nmol/L).ResultsVitamin D levels (mean = 62.1 nmol/L, 95%CI 60.4–63.7) were insufficient in 35%, and decreased with age in both sexes (p<0.001). Young People living between 53–59 degrees latitude had lower levels (compared with 50–53 degrees, p = 0.045). Dietary intake and gender had no effect on vitamin D status. A logistic regression model showed increased risk of VDI in the following: adolescents (14–18 years old), odds ratio (OR) = 3.6 (95%CI 1.8–7.2) compared with younger children (4–8 years); non white children (OR = 37 [95%CI 15–90]); blood levels taken December-May (OR = 6.5 [95%CI 4.3–10.1]); on income support (OR = 2.2 [95%CI 1.3–3.9]); not taking vitamin D supplementation (OR = 3.7 [95%CI 1.4–9.8]); being overweight (OR 1.6 [95%CI 1.0–2.5]); <1/2 hour outdoor exercise/day/week (OR = 1.5 [95%CI 1.0–2.3]); watched >2.5 hours of TV/day/week (OR = 1.6[95%CI 1.0–2.4]).ConclusionWe confirm a previously under-recognised risk of VDI in adolescents. The marked higher risk for VDI in non-white children suggests they should be targeted in any preventative strategies. The association of higher risk of VDI among children who exercised less outdoors, watched more TV and were overweight highlights potentially modifiable risk factors. Clearer guidelines and an increased awareness especially in adolescents are needed, as there are no recommendations for vitamin D supplementation in older children. 相似文献
9.
Combes V Coltel N Faille D Wassmer SC Grau GE 《International journal for parasitology》2006,36(5):541-546
Brain lesions of cerebral malaria (CM) are characterised by a sequestration of Plasmodium falciparum-parasitised red blood cells (PRBC), leucocytes and platelets within brain microvessels, by an excessive release of pro-inflammatory cytokines as well as by disruption of the blood-brain barrier (BBB). We evaluated the possibility that PRBC and platelets interact and induce functional alterations in brain endothelium. Using an in vitro model of endothelial lesion, we showed that platelets can act as bridges between PRBC and endothelial cells (EC) allowing the binding of PRBC to endothelium devoid of cytoadherence receptors. Furthermore, platelets potentiated the cytotoxicity of PRBC for brain EC by inducing an alteration of the integrity of their monolayer and increasing their apoptosis. These findings provide insights into the mechanisms by which platelets can be deleterious to the brain endothelium during CM. Another aspect of inflammatory and infectious diseases is that they often lead to activation of vascular and blood cells. Such activation results in an enhanced vesiculation, i.e. the release of circulating microparticles (MP). We thus explored plasma levels of endothelial MP in Malawian children with malaria. Plasma MP numbers were markedly increased on admission only in patients with severe malaria complicated with coma. Using the experimental mouse model of CM, we evaluated the pathogenic implications of MP using genetically deficient mice in which the capacity to vesiculate is impaired. Such mice, lacking the ABCA-1 gene, upon infection by Plasmodium berghei ANKA, showed complete resistance to CM. When purified from infected susceptible animals, MP were able to reduce normal plasma clotting time and to significantly enhance tumour necrosis factor release from na?ve macrophages. Altogether these data provide a novel insight into the pathogenic mechanisms leading to the neurological syndrome. The finding that ABCA-1 gene deletion confers complete protection against cerebral pathology, linked to an impaired MP production, provides new potential targets for therapeutic amelioration of severe malaria. 相似文献
10.
U Augenstein A Ronai B Wassmer S de Looze O von Deimling 《Comparative biochemistry and physiology. B, Comparative biochemistry》1988,91(1):171-177
1. Abdominal lymph was obtained from Mus musculus by cannulation of the thoracic duct: lymph esterases were identified by polyacrylamide gel electrophoresis. Seven known esterases (ES-1, ES-2, ES-5, ES-27, SE-I, SE-II and SE-III) and a newly described activity (SE-IV) were demonstrated, all of which were also present in serum. 2. Electrophoretic staining intensities indicated that the lymph esterases were less concentrated than the corresponding activities in serum, with the single exception of ES-2. This finding was supported by quantitative immunoelectrophoresis of ES-1 and ES-2 (two allozymes each). 3. The jejunum appeared to be the origin of lymph ES-2 by a comparison of organ distribution of the allozymes ES-2B and ES-2D and by monitoring the re-appearance of ES-2 in several organs, serum and lymph after total inhibition in vivo by bis-p-nitrophenyl phosphate. 相似文献