Home About us Contact
|
Home About us Contact | ||
|
|
||
Background Previous Studies (background + previous_studies)
Selected AbstractsIncidence and geographical distribution of sudden infant death syndrome in relation to content of nitrate in drinking water and groundwater levelsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 12 2001M. George Background Previous studies indicate that the enteral bacterial urease is inhibited in victims of sudden infant death syndrome (SIDS). One possible inhibitor of this bacterial activity is nitrate. If ambient pollution by nitrate is involved in the etiology of SIDS only a fraction of the nitrate concentration not infrequently found in drinking water would be enough for this inhibition. Methods Occurrence of SIDS (n = 636) in Sweden during the period 1990 through 1996 were analysed regarding geographical and seasonal distribution in relation to the nitrate concentration in drinking water and changes in the groundwater level. Results Both the birth rate and the incidence of SIDS decreased during the study period. One quarter of the municipalities constituting 11% of the population had no cases, the maximum incidence being 6·5 per 1000 live births. Seasonality: The northernmost parts of the country had its highest incidence when the rest of the country had its lowest incidence, and the occurrence of individual deaths was associated with the recharge of groundwater which increases its nitrate content. The local incidence of SIDS was correlated (rs = 0·34,0·87) to maximally recorded concentrations of nitrate in drinking water. Conclusions The seasonal distribution of SIDS was widely different from the south to the north of the country and seems to be associated with differences in the groundwater level changes subsequent to precipitation, frost penetration, and melting of snow. Use of drinking water with high peak concentrations or great variations in nitrate concentration was correlated to the incidence of SIDS. [source] Body mass index in adults with intellectual disability: distribution, associations and service implications: a population-based prevalence studyJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 4 2008S. Bhaumik Abstract Background Previous studies of weight problems in adults with intellectual disability (ID) have generally been small or selective and given conflicting results. The objectives of our large-scale study were to identify inequalities in weight problems between adults with ID and the general adult population, and to investigate factors associated with obesity and underweight within the ID population. Methods We undertook a population-based prevalence study of 1119 adults with ID aged 20 and over on the Leicestershire Learning Disability Register who participated in a programme of universal health checks and home interviews with their carers. We performed a cross-sectional analysis of the register data and compared the observed and expected prevalences of body mass index categories in the ID and general populations using indirect standardisation for age. We used logistic regression to evaluate the association of a range of probable demographic, physical, mental and skills attributes with obesity and underweight. Results In those aged 25 and over, the standardised morbidity ratio (SMR) for obesity was 0.80 (95% CI 0.64,1.00) in men and 1.48 (95% CI 1.23,1.77) in women. The SMR for underweight was 8.44 (95% CI 6.52,10.82) in men and 2.35 (95% CI 1.72,3.19) in women. Among those aged 20 and over, crude prevalences were 20.7% for obesity, 28.0% for overweight, 32.7% for normal weight and 18.6% for underweight. Obesity was associated with living independently/with family, ability to feed/drink unaided, being female, hypertension, Down syndrome and the absence of cerebral palsy. Underweight was associated with younger age, absence of Down syndrome and not taking medication. Conclusion Obesity in women and underweight in both men and women was more common in adults with ID than in the general population after controlling for differences in the age distributions between the two populations. The associated factors suggest opportunities for targeting high-risk groups within the ID population for lifestyle and behaviour modification. [source] Plasma levels of opioid peptides after sunbed exposuresBRITISH JOURNAL OF DERMATOLOGY, Issue 6 2002T. Gambichler Summary Background Previous studies have indicated that solar and artificial ultraviolet (UV) radiation have a positive influence on psychological variables such as mood and emotional state. Circulating opioid peptides have been suggested as being important in this effect. Objectives To investigate in a controlled trial the influence of UVA radiation on opioid peptide levels. Methods We determined plasma levels of ,-endorphin immunoreactive material (IRM) and met-enkephalin in UV-exposed ( n = 35) and non-exposed ( n = 9) healthy volunteers. On the first day of the study, blood samples were taken from the volunteers (time A). UVA irradiation was subsequently administered with an air-conditioned tanning device. During the UV exposures the volunteers wore opaque goggles. Twenty minutes after UV exposure, blood samples were collected again (time B). Within the following 3 weeks the volunteers had a series of five UV exposures. On the last day of the study (24 h after the sixth UV exposure) blood samples were collected (time C). The cumulative UVA doses were 96 J cm ,2 for skin type II and 126 J cm ,2 for skin type III. The controls had no UV exposures. Plasma ,-endorphin IRM and met-enkephalin levels were determined using radioimmunoassays. Results At all times of blood collection (A, B, C), there were no significant differences in plasma levels of ,-endorphin IRM and met-enkephalin between UV-exposed and non-exposed volunteers ( P > 0·05). Conclusions UVA irradiation does not significantly elevate plasma levels of ,-endorphin IRM and met-enkephalin. Therefore we suggest that psychological benefits claimed to occur after UV exposure are unlikely to be mediated by the types of circulating opioid peptides measured in this study. [source] Epidermal proliferative response induced by sodium dodecyl sulphate varies with environmental humidityBRITISH JOURNAL OF DERMATOLOGY, Issue 2 2001M. Denda Background Previous studies have suggested that susceptibility of skin to external agents increases in the dry winter season. Objectives To test the hypothesis that environmental humidity affects skin sensitivity to irritants. Methods The epidermal hyperplasia induced by sodium dodecyl sulphate (SDS) under various humidity conditions was evaluated on the skin of hairless mice. Results Mice kept under low humidity for 2 days showed more obvious epidermal proliferation 24 h after topical application of SDS than those kept under high or normal humidity for 2 days. In contrast, mice kept under high humidity for 2 weeks showed more obvious epidermal proliferation 24 h after topical application of SDS than those kept under low or normal humidity. The transepidermal water loss was altered significantly in the animals kept under high humidity for 2 weeks, although it was not altered during the first 7 days under either low or high humidity. Conclusions These results suggest that environmental humidity influences the sensitivity of skin to topical application of SDS and that increased sensitivity is not always associated with alteration of the water impermeability of the stratum corneum. [source] What helps when it hurts: children's views on pain reliefCHILD: CARE, HEALTH AND DEVELOPMENT, Issue 4 2008L. S. Franck Abstract Background Previous studies have focused on children's views of sources of pain and only secondarily explored their views on pain-relief strategies. Methods An exploratory cross-sectional descriptive design and ,draw and write' technique were used to investigate what children think helps them when they have pain. Results The sample (n = 71) was comprised of 33% boys and 67% girls, with an age range of 4,16 years (mean ± SD: 9.25 ± 3.04). Four overarching themes were derived that were common to both the texts and drawings: ,People who help', ,What I do that helps', ,What other people do that helps' and ,Things that help'. Children also described their emotional reactions to pain or pain relief. Multiple themes were represented in most of the texts and drawings. There were few differences in the themes present in the children's texts and drawings based on developmental age and no differences based on gender. Conclusions Children across the three developmental age groups view themselves as active agents in pain relief. Although less than half of the children described specific behaviours they had taken, almost all children indicated their active role as the central figure in relation to use of objects or the actions of others. [source] The development and standardization of the Children Activity Scales (ChAS-P/T) for the early identification of children with Developmental Coordination DisordersCHILD: CARE, HEALTH AND DEVELOPMENT, Issue 6 2006S. Rosenblum Abstract Background Previous studies have emphasized the importance of early identification of children with Developmental Coordination Disorder (DCD) to prevent the development of secondary academic, emotional and social manifestations of the disorder. The aim of this study was to develop a valid parent and teacher questionnaire , the Children Activity Scales for parents (ChAS-P) and for teachers (ChAS-T) , to identify children aged 4,8 years at risk for DCD and to examine the reliability and validity of these questionnaires. Methods The questionnaires' content and face validity were established, and then cut-off scores were determined based on responses of 355 teachers and 216 parents. Internal consistencies were also calculated. Factor analyses were performed, and construct validity was determined by examining the questionnaires' ability to discriminate between 30 children aged 5,6.5 years diagnosed with DCD and 30 typically developing children. Concurrent validity was examined by comparing questionnaire scores with those of the Movement Assessment Battery for Children (M-ABC). Results High values were obtained for internal consistency (0.96,0.94) for the ChAS-T and the ChAS-P respectively. Factor analysis revealed four distinct factors within the ChAS-P and three within the ChAS-T, reinforcing the theoretical validity of the items selected and appropriateness for identifying DCD. Construct validity was indicated by finding significant differences between the groups' scores on the ChAS-T and the ChAS-P. Significant correlations between the children's scores on the questionnaires and those of the M-ABC confirmed their concurrent validity. Conclusions Initial results suggest that the ChAS-T and Chas-P are reliable tools to identify children at risk for DCD. [source] Blockade of superoxide generation prevents high-affinity immunoglobulin E receptor-mediated release of allergic mediators by rat mast cell line and human basophilsCLINICAL & EXPERIMENTAL ALLERGY, Issue 4 2002T. Yoshimaru Summary Background Previous studies have shown that rat peritoneal mast cells and mast cell model rat basophilic leukaemia (RBL-2H3) cells generate intracellular reactive oxygen species (ROS) in response to antigen challenge. However, the physiological significance of the burst of ROS is poorly understood. Objective The present study was undertaken to investigate the role of superoxide anion in mediator release in rat and human cell systems. Methods RBL-2H3 cells were directly stimulated with anti-rat Fc,RI ,-subunit monoclonal antibody (mAb). For the analysis of human cell system, leucocytes were isolated by dextran sedimentation from healthy volunteers or from patients, and challenged either with anti-human Fc,RI mAb or with the relevant antigens. Superoxide generation was determined by chemiluminescence-based methods. The releases of histamine and leukotrienes (LT)s were determined by enzyme-linked immunosorben assay (ELISA). Results Cross-linking of Fc,RI on RBL-2H3 cells or on human leucocytes from healthy donors by the anti-Fc,RI mAb resulted in a rapid generation of superoxide anion, as determined by chemiluminescence using superoxide-specific probes. Similarly, leucocytes from patients generated superoxide anion in response to the challenge with the relevant allergen but not with the irrelevant allergen. Furthermore, diphenyleneiodonium (DPI), a well-known inhibitor of flavoenzymes suppressed the superoxide generation and the release of histamine and LTC4 induced by the anti-Fc,RI mAb or by allergen in parallel. Conclusion These results indicate that both RBL-2H3 cells and human basophils generate superoxide anion upon Fc,RI cross-linking either by antibody or by allergen challenge and that blockade of the generation prevents the release of allergic mediators. The findings strongly support the role of superoxide generation in the activation of mast cells and basophils under both physiological and pathological conditions. The findings suggest that drugs regulating the superoxide generation have potential therapeutic use for allergic disorders. [source] | ||||||||||