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排序方式: 共有350条查询结果,搜索用时 15 毫秒
91.
Linsen L Thewissen M Baeten K Somers V Geusens P Raus J Stinissen P 《Arthritis research & therapy》2005,7(3):R493-R502
Natural killer T (NKT) cells have been implicated in the regulatory immune mechanisms that control autoimmunity. However,
their precise role in the pathogenesis of rheumatoid arthritis (RA) remains unclear. The frequency, cytokine profile and heterogeneity
of NKT cells were studied in peripheral blood mononuclear cells (PBMCs) from 23 RA patients and 22 healthy control individuals,
including paired PBMC–synovial fluid samples from seven and paired PBMC–synovial tissue samples from four RA patients. Flow
cytometry revealed a decreased frequency of NKT cells in PBMCs from RA patients. NKT cells were present in paired synovial
fluid and synovial tissue samples. Based on the reactivity of PBMC-derived NKT cells toward α-galactosylceramide, RA patients
could be divided into responders (53.8%) and nonresponders (46.2%). However, NKT cells isolated from synovial fluid from both
responders and nonresponders expanded upon stimulation with α-galactosylceramide. Analysis of the cytokine profile of CD4+ and CD4- PBMC derived NKT cell lines from RA patients revealed a significantly reduced number of IL-4 producing cells. In contrast,
synovial fluid derived NKT cell lines exhibited a Th0-like phenotype, which was comparable to that in healthy control individuals.
This suggests that synovial fluid NKT cells are functional, even in patients with nonresponding NKT cells in their blood.
We conclude that, because the number of Vα24+Vβ11+CD3+ NKT cells is decreased and the cytokine profile of blood-derived NKT cells is biased toward a Th1-like phenotype in RA patients,
NKT cells might be functionally related to resistance or progression of RA. Providing a local boost to the regulatory potential
of NKT cells might represent a useful candidate therapy for RA. 相似文献
92.
Background
Although increased prevalence of transfusion transmissible infections (TTI) among “men who have sex with men” (MSM) has been well documented, the exclusion of MSM as blood donors is contested. The aim of this systematic review is to find studies that describe the risk of TTI in MSM blood donors.Methods
We searched MEDLINE, Embase, The Cochrane Central Register of Controlled Trials, Cinahl, and Web of Science, and used GRADE for determining evidence quality. We included studies comparing MSM and non-MSM blood donors (or people eligible to give blood), living in areas most relevant for our Blood Service.Results
Out of 18 987 articles, 14 observational studies were included. Two studies directly compared MSM with non-MSM donors showing that MSM donors have a statistically significant higher risk of HIV-1 infections. In one of these studies it was shown that this was related to recent (< 12 months) MSM contact. In two additional studies no evidence was shown in favour of a certain deferral period for MSM. Ten studies, applying permanent deferral for MSM, compared infected versus non-infected donors. One study found that MSM is a statistically significant risk factor for HIV-1 infection in blood donors. For other TTI such as HBV or HCV, an increased risk of infection could not be demonstrated, because the precision of the results was affected by the low numbers of donors with MSM as risk factor, or because of risk of bias in the included studies. All studies included low level evidence, because of risk of bias and imprecision of the results.Conclusions
High-quality studies investigating the risk of TTI in MSM who donate blood are scarce. The available evidence suggests a link between MSM blood donors and HIV-1 infection, but is too limited to be able to unambiguously/clearly recommend a certain deferral policy. 相似文献93.
Maarten Sonnaert Greet Kerckhofs Ioannis Papantoniou Sandra Van Vlierberghe Veerle Boterberg Peter Dubruel Frank P. Luyten Jan Schrooten Liesbet Geris 《PloS one》2015,10(6)
To progress the fields of tissue engineering (TE) and regenerative medicine, development of quantitative methods for non-invasive three dimensional characterization of engineered constructs (i.e. cells/tissue combined with scaffolds) becomes essential. In this study, we have defined the most optimal staining conditions for contrast-enhanced nanofocus computed tomography for three dimensional visualization and quantitative analysis of in vitro engineered neo-tissue (i.e. extracellular matrix containing cells) in perfusion bioreactor-developed Ti6Al4V constructs. A fractional factorial ‘design of experiments’ approach was used to elucidate the influence of the staining time and concentration of two contrast agents (Hexabrix and phosphotungstic acid) and the neo-tissue volume on the image contrast and dataset quality. Additionally, the neo-tissue shrinkage that was induced by phosphotungstic acid staining was quantified to determine the operating window within which this contrast agent can be accurately applied. For Hexabrix the staining concentration was the main parameter influencing image contrast and dataset quality. Using phosphotungstic acid the staining concentration had a significant influence on the image contrast while both staining concentration and neo-tissue volume had an influence on the dataset quality. The use of high concentrations of phosphotungstic acid did however introduce significant shrinkage of the neo-tissue indicating that, despite sub-optimal image contrast, low concentrations of this staining agent should be used to enable quantitative analysis. To conclude, design of experiments allowed us to define the most optimal staining conditions for contrast-enhanced nanofocus computed tomography to be used as a routine screening tool of neo-tissue formation in Ti6Al4V constructs, transforming it into a robust three dimensional quality control methodology. 相似文献
94.
95.
Jelle Van Cauwenberg Veerle Van Holle Ilse De Bourdeaudhuij Neville Owen Benedicte Deforche 《PloS one》2015,10(8)
Introduction
Insights into the diurnal patterns of sedentary behavior and the identification of subgroups that are at increased risk for engaging in high levels of sedentary behavior are needed to inform potential interventions for reducing older adults’ sedentary time. Therefore, we examined the diurnal patterns and sociodemographic correlates of older adults’ sedentary behavior(s).Methods
Stratified cluster sampling was used to recruit 508 non-institutionalized Belgian older adults (≥ 65 years). Morning, afternoon, evening and total sedentary time was assessed objectively using accelerometers. Specific sedentary behaviors, total sitting time and sociodemographic attributes were assessed using an interviewer-administered questionnaire.Results
Participants self-reported a median of 475 (Q1-Q3 = 383–599) minutes/day of total sitting time and they accumulated a mean of 580 ± 98 minutes/day of accelerometer-derived sedentary time. Sedentary time was lowest during the morning and highest during the evening. Older participants were as sedentary as younger participants during the evening, but they were more sedentary during daytime. Compared to married participants, widowers were more sedentary during daytime. Younger participants (< 75 years), men and the higher educated were more likely to engage in (high levels of) sitting while driving a car and using the computer. Those with tertiary education viewed 29% and 22% minutes/day less television compared to those with primary or secondary education, respectively. Older participants accumulated 35 sedentary minutes/day more than did younger participants and men accumulated 32 sedentary minutes/day more than did women.Conclusion
These findings highlight diurnal variations and potential opportunities to tailor approaches to reducing sedentary time for subgroups of the older adult population. 相似文献96.
Hélène De Naeyer Veerle Bogaert Annelies De Spaey Greet Roef Sara Vandewalle Wim Derave Youri Taes Jean-Marc Kaufman 《PloS one》2014,9(1)
Objective
The relationship between serum testosterone (T) levels, muscle mass and muscle force in eugonadal men is incompletely understood. As polymorphisms in the androgen receptor (AR) gene cause differences in androgen sensitivity, no straightforward correlation can be observed between the interindividual variation in T levels and different phenotypes. Therefore, we aim to investigate the relationship between genetic variations in the AR, circulating androgens and muscle mass and function in young healthy male siblings.Design
677 men (25–45 years) were recruited in a cross-sectional, population-based sibling pair study.Methods
Relations between genetic variation in the AR gene (CAGn, GGNn, SNPs), sex steroid levels (by LC-MS/MS), body composition (by DXA), muscle cross-sectional area (CSA) (by pQCT), muscle force (isokinetic peak torque, grip strength) and anthropometrics were studied using linear mixed-effect modelling.Results
Muscle mass and force were highly heritable and related to age, physical activity, body composition and anthropometrics. Total T (TT) and free T (FT) levels were positively related to muscle CSA, whereas estradiol (E2) and free E2 (FE2) concentrations were negatively associated with muscle force. Subjects with longer CAG repeat length had higher circulating TT, FT, and higher E2 and FE2 concentrations. Weak associations with TT and FT were found for the rs5965433 and rs5919392 SNP in the AR, whereas no association between GGN repeat polymorphism and T concentrations were found. Arm span and 2D:4D finger length ratio were inversely associated, whereas muscle mass and force were not associated with the number of CAG repeats.Conclusions
Age, physical activity, body composition, sex steroid levels and anthropometrics are determinants of muscle mass and function in young men. Although the number of CAG repeats of the AR are related to sex steroid levels and anthropometrics, we have no evidence that these variations in the AR gene also affect muscle mass or function. 相似文献97.
Nathalie Vaes Simone L Schonkeren Glenn Rademakers Amy M Holland Alexander Koch Marion J Gijbels Tom G Keulers Meike de Wit Laura Moonen Jaleesa R M Van der Meer Edith van den Boezem Tim G A M Wolfs David W Threadgill Jeroen Demmers Remond J A Fijneman Connie R Jimenez Pieter Vanden Berghe Kim M Smits Kasper M A Rouschop Werend Boesmans Robert M W Hofstra Veerle Melotte 《EMBO reports》2021,22(6)
The N‐Myc Downstream‐Regulated Gene 4 (NDRG4), a prominent biomarker for colorectal cancer (CRC), is specifically expressed by enteric neurons. Considering that nerves are important members of the tumor microenvironment, we here establish different Ndrg4 knockout (Ndrg4 −/−) CRC models and an indirect co‐culture of primary enteric nervous system (ENS) cells and intestinal organoids to identify whether the ENS, via NDRG4, affects intestinal tumorigenesis. Linking immunostainings and gastrointestinal motility (GI) assays, we show that the absence of Ndrg4 does not trigger any functional or morphological GI abnormalities. However, combining in vivo, in vitro, and quantitative proteomics data, we uncover that Ndrg4 knockdown is associated with enlarged intestinal adenoma development and that organoid growth is boosted by the Ndrg4 −/− ENS cell secretome, which is enriched for Nidogen‐1 (Nid1) and Fibulin‐2 (Fbln2). Moreover, NID1 and FBLN2 are expressed in enteric neurons, enhance migration capacities of CRC cells, and are enriched in human CRC secretomes. Hence, we provide evidence that the ENS, via loss of Ndrg4, is involved in colorectal pathogenesis and that ENS‐derived Nidogen‐1 and Fibulin‐2 enhance colorectal carcinogenesis. 相似文献
98.
Everaert N Willemsen H Kamers B Decuypere E Bruggeman V 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2011,158(2):215-220
It has been shown that during embryonic chicken (Gallus gallus) development, the metabolism of broiler embryos differs from that of layers in terms of embryonic growth, pCO2/pO2 blood levels, heat production, and heart rate. Therefore, these strains might adapt differently on extreme environmental factors such as exposure to high CO2. The aim of this study was to compare broiler and layer embryos in their adaptation to 4% CO2 from embryonic days (ED) 12 to 18. Due to hypercapnia, blood pCO2 increased in both strains. Blood bicarbonate concentration was ~10 mmol/L higher in embryos exposed to high CO2 of both strains, while the bicarbonates of broilers had ~5 mmol/L higher values than layer embryos. In addition, the pH increased when embryos of both strains were exposed to CO2. Moreover, under CO2 conditions, the blood potassium concentration increased in both strains significantly, reaching a plateau at ED14. At ED12, the layer strain had a higher increase in CAII protein in red blood cells due to incubation under high CO2 compared to the broiler strain, whereas at ED14, the broiler strain had the highest increase. In conclusion, the most striking observation was the similar mechanism of broiler and layer embryos to cope with high CO2 levels. 相似文献
99.
100.