The hygiene hypothesis implies that the increasing prevalence of allergy in 'westernized' countries is explained by reduced bacterial exposure in early life, but the underlying mechanism remains elusive. We therefore wanted to study the effect of bacterial lipopolysaccharide (LPS) on the generation of regulatory T (T(R)) cells in neonates, and to analyze differences between neonates with allergy risk because of a family history of atopy (FH+) and controls without such hereditary risk (FH-). Cord blood mononuclear cells from the FH+ and FH- groups were stimulated with beta-lactoglobulin in the presence of LPS. T-cell phenotypes suggestive of T(R) cells [CD25+, CD25high and integrin (CD103+)], and the intracellular proliferation antigen Ki-67 were quantified by flow cytometry. Release of the immunosuppressive cytokine transforming growth factor beta1 (TGF-beta1) from its inactive complex was determined by enzyme-linked immunosorbent assay. The analyses revealed the generation of T-cell phenotypes suggestive of T(R) cells including a CD25high T-cell subset which was inversely related to T-cell proliferation (r=-0.54, p<0.05) and to activation-induced release of TGF-beta1 (r=-0.80, p<0.001). The CD25high T-cell subset tended to be impaired in the FH+ group (% of CD3+ T cells: FH+, 5.1% vs. FH-, 12.6%), and notably, the FH+ group showed a significantly reduced capacity for generation of both CD25+ (FH+, 16.2% vs. FH-, 34.9%; p<0.01) and T cells (FH+, 2.1% vs. FH-, 3.9%; p<0.05). Our findings suggested that early-life exposure to a dietary antigen in the presence of LPS might modulate the immune system by generating T(R) cells. This capacity was impaired in neonates with hereditary allergy risk, but clinical follow-up will be required to determine a possible effect on allergy emergence. 相似文献
Thirty healthy nonsmoking men and 30 women underwent a laboratory reactivity assessment with systolic (SBP) and diastolic blood pressure (DBP), and heart rate (HR) recorded at rest and during behavioral (mirror image tracing, mental arithmetic, color word conflict task and a semistructured Type A interview), and physical tasks (isometric exercise and the cold pressor test). Casual SBP and DBP were measured in a physician's clinic. Four months earlier SBP, DBP and HR had been monitored during a day at work and a day at home. Readings obtained in the clinic, at rest and during stress in the laboratory were related to real-life levels, reactivity (work—home difference) and variability.
For men level of cardiovascular activation at rest and during all stressors in the laboratory correlated with levels at work and at home. The best laboratory/real-life relation was observed for SBP. Systolic blood pressure levels during stress correlated with the work—home difference. Systolic blood pressure reactivity (laboratory stress levels—rest levels) to most behavioral tasks correlated with SBP levels at work and home. Daily variability and reactivity correlated with SBP reactivity to mental arithmetic and the color word conflict task. For women, levels of SBP and HR at rest and during all stressors correlated with SBP and HR at work and at home. The best laboratory/real-life relation for women was observed for HR reactivity. Casual BP in the clinic correlated with work blood pressure but generally not with daily reactivity or variability.
We conclude that BP and HR levels measured in the laboratory generalizes to real life BP and HR in both men and women and also to real life SBP reactivity in men. Laboratory induced SBP reactivity also shows a weak relation to real life SBP levels, variability and reactivity in men. 相似文献
Adult male Han/Wistar rats were administered 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) intraperitoneally at doses ranging from 125 to 1400 micrograms/kg and monitored for 39 to 48 days. Two rats succumbed in the course of the experiment: one in the group receiving 625 and one dosed 1000 micrograms/kg. Body weights of the animals decreased by 20 to 30% during the first 10 to 14 days and became stable thereafter. Feed consumption decreased to 1/3-1/2 of control levels by Day 4 (calculated per metabolic body mass) and returned gradually to starting values by about 4 weeks after dosing. Water intake displayed a triphasic pattern: at first it was slightly increased (Days 1 to 3), then reduced (on Days 4 to 12) and finally increased again throughout the remainder of the test period. The absolute and/or relative weights of thymus, testicles, ventral prostate and interscapular brown fat were significantly decreased at termination. These results indicate that the LD50-value for TCDD in the male, adult Han/Wistar rat is substantially above 1400 micrograms/kg, and that suppression of appetite is the principal phenomenon responsible for TCDD-induced body weight reduction. 相似文献
The aim of this study was to utilise a new approach where digital image information is used in the characterisation of particle size distributions of a large set of pharmaceutical powders. A novel optical set-up was employed to create images and calculate a stereometric parameter from the digital images of powder surfaces. Analysis was made of 40 granule batches with varying particle sizes and compositions prepared with fluidised bed granulation. The extracted digital image information was then connected to particle size using multivariate modelling. The modelled particle size distributions were compared to particle size determinations with sieve analysis and laser diffraction. The results revealed that the created models corresponded well with the particle size distributions measured with sieve analysis and laser diffraction. This study shows that digital images taken from powder surfaces contain all necessary data that is needed for particle size distribution analysis. To obtain this information from images careful consideration has to be given on the imaging conditions. In conclusion, the results of this study suggest that the new approach is a powerful means of analysis in particle size determination. The method is fast, the sample size needed is very small and the technique enables non-destructive analysis of samples. The method is suitable in the particle size range of approximately 20–1500 μm. However, further investigations with a broad range of powders have to be made to obtain information of the possibilities and limitations of the introduced method in powder characterisation. 相似文献
Objective: Comprehensive understanding of the prevalence and quality of work disabilities and unmet needs for health care and rehabilitation to support return to work (RTW) among jobseekers.Design: Community-level, cross-sectional analysis with multidimensional clinical work ability assessments.Setting: Paltamo, Finland.Participants: Unemployed citizens either participating in the Full-Employment Project or long-term unemployed (n?=?230, 81%).Main outcome measures: Based on data from theme interviews, patient records, supervisors’ observations of work performance and clinical examinations, a physician concluded the individual’s work ability, categorised into four groups: good work ability, good work ability expected after RTW support, able to transitional work only or unable to work. These groups were cross tabulated with primary diagnoses, types of plans to support RTW, as well as categories of social functioning and motivation, for which sensitivity and specificity scores in detecting work disability were calculated.Results: Only about half of the jobseekers had good work ability, 27% were found unable to work in the open labour market and 15% even eligible for a disability pension. For 20%, care or rehabilitation was seen necessary to enable RTW. Poor supervisor- and self-rated performance at work or poor social functioning appeared as sensitive measures in detecting work disability.Conclusions: Work disabilities and unmet needs for health care and rehabilitation are highly prevalent among jobseekers, as depicted using a multidimensional work ability assessment procedure inspired by the International Classification of Functioning (ICF). Further development of work ability assessment practices is clearly needed.
KEY POINTS
Although the association of unemployment with poor health is well known, evidence on the work ability of the unemployed remains scarce.
Work disabilities are common among the unemployed.
Multidimensional work ability assessment among the unemployed reveals unmet needs for care and rehabilitation to support return to work.
Context sensitivity may add to the accuracy of the doctor’s conclusions on work ability.