Home About us Contact
|
Home About us Contact | ||
|
|
||
Previous Published (previous + published)
Selected AbstractsHave studies of urinary tract infection and preterm delivery used the most appropriate methods?PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 3 2003Marie S. O'Neill Summary Published investigations of the association between urinary tract infection (UTI) and preterm delivery used logistic regression or chi-squared tests. Because both exposure and outcome are time dependent, these methods were not optimal and did not account for person,time under observation, potentially an important feature given the variability of women's entry to prenatal care as well as of gestational lengths. Previous researchers probably classified as exposed some women whose UTI occurred after their pregnancies exceeded 37 weeks. We applied the previous analytical methods to 1990,93 births from two Durham, NC, USA, hospitals (n = 4053) and demonstrate survival methods as an alternative. Two logistic regression models were fitted with differing exposure definitions: model 1 in which exposed = UTI diagnosed after 20 weeks' gestation; and model 2 in which exposed = UTI diagnosed between 20 weeks' and 37 weeks' gestation. Model 3 used proportional hazards regression with person,time after 20 weeks and before UTI diagnosis as unexposed, and person,time after diagnosis as exposed. Models were fit with and without five time-constant potential confounders. Model 1 yielded an adjusted odds ratio (OR) of 0.8 [95% confidence interval (CI) 0.5, 1.2], and model 2, which did not include UTI diagnoses after 37 weeks, an adjusted OR of 0.9 [95% CI 0.6, 1.4]. The Cox model hazard ratio (HR) for preterm delivery was 1.1 (adjusted) [95% CI 0.7, 1.7]. As these results indicated some bias, but not remarkable differences, we conducted a sensitivity analysis using 100 samples of 80% of the original data set, with replacement to determine how large the differences might be in other, similar data sets. The Cox method consistently produced higher effect estimates than either logistic model. The two samples with the greatest differences between the Cox and logistic model estimates yielded an OR of 1.47 [95% CI 0.95, 2.29] for model 1 vs. HR of 2.06 [95% CI 1.39, 3.06] for model 3, and an OR of 1.41 [95% CI 0.88, 2.25] for model 2 vs. HR of 1.79 [95% CI 1.17, 2.71] for model 3 respectively. Previous published results on UTI and preterm delivery require cautious interpretation. Data on UTI timing should be gathered to allow appropriate analyses; survival methods account for person,time under observation and ensure that studied exposures precede effects. [source] Quantitative PCR assays to survey the bovine adenovirus levels in environmental samplesJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2010K. Wong Abstract Aims:, Previous studies suggested bovine adenoviruses (BAdVs) could be used as cattle faecal indicators. The main aim of this study was to survey the levels of BAdV in environmental samples using quantitative polymerase chain reaction (qPCR). Methods and Results:, Two qPCR assays were developed to identify and quantify BAdVs in environmental samples. BAdVs were detected in all dairy manure, and in most cases, the sample concentrations were around 103,104 copies ml,1. Farm tile drainage samples were also detected, but the concentrations were about 1,3 log10 lower than the BAdV concentrations in the manure samples. The genome equivalent copy (GEC) levels of BAdV and the phage forming unit (PFU) levels of somatic phage in manure samples were comparable. Four of twenty individual cattle faeces were positive with concentrations similar to that found in the manure samples. Sequencing results confirmed the presence of BAdV in the environmental samples, and phylogenetic analysis indicated that BAdV 2 and 4 were the most prevalent serotypes in all the manure samples tested. The qPCR assays developed in this study showed higher sensitivity in detecting BAdV 1 and 2 than the previous published nested assay. Conclusion:, The high levels of BAdV in the environmental samples may suggest it could be used for bovine faecal indicator. The significant levels of BAdV in the drainage samples may indicate the potential of surface water pollution by the manure applied to farm fields. Significance and Impact of the Study:, This is the first study that reports the quantitative level of BAdV in environmental samples. These results could be useful when it comes to determining whether BAdV could be utilized as a bovine faecal indicator. [source] Food allergy and food sensitization in early childhood: results from the DARC cohortALLERGY, Issue 7 2009E. Eller Background:, The prevalence of food hypersensitivity (FHS) and the relationship with atopic dermatitis (AD) is controversial. The aim of this study was to determine the development of FHS and to correlate this with AD in relation to sensitization and symptoms. Methods:, This study combines new data from birth to 18 months of age with previous published results from 3 and 6 years. The Danish Allergy Research Centre cohort, including 562 children, is a unique, population-based, prospective birth cohort, with clinical examinations at all follow-ups. All children were examined for the development of AD using Hanifin-Rajka criteria and for FHS using interviews, skin prick test (SPT), specific immunoglobulin E (IgE), and food challenge according to EAACI guidelines. Results:, Twenty children were confirmed with FHS to milk, egg, and peanut. FHS peaked at 18 months (3.6%) and then decreased to 1.2% at 72 months of age. No new cases were found after 3 years. Self-reporting could only be confirmed in 31% of cases. Among the 122 children with AD, 18 had FHS (14.8%). FHS was IgE-mediated in 95% of the cases but 16 of 20 children were additionally sensitized to other foods which they tolerated. Children with AD were neither more IgE-sensitized nor had higher levels of IgE when compared with healthy children but they were more persistently sensitized. Conclusions:, Sensitization to foods in young children without food allergy seems to be a normal phenomenon. The discrepancy between sensitization, self-reported food-related symptoms and confirmed FHS illustrates the need to perform standardized oral challenges in order to confirm the diagnosis of FHS. [source] Fast liquid composite molding simulation of unsaturated flow in dual-scale fiber mats using the imbibition characteristics of a fabric-based unit cellPOLYMER COMPOSITES, Issue 10 2010Hua Tan The use of the dual-scale fiber mats in liquid composite molding (LCM) process for making composites parts gives rise to the unsaturated flow during the mold-filling process. The usual approaches for modeling such flows involve using a sink term in the mass balance equation along with the Darcy's law. Sink functions involving complex microflows inside tows with realistic tow geometries have not been attempted in the past because of the problem of high computational costs arising from the coupling of the macroscopic gap flows with the microscopic tow flows. In this study, a new "lumped" sink function is proposed for the isothermal flow simulation, which is a function of the gap pressure, capillary pressure, and tow saturation, and which is estimated without solving for the microscopic tow simulations at each node of the FE mesh in the finite element/control volume algorithm. The sink function is calibrated with the help of the tow microflow simulation in a stand-alone unit cell of the dual-scale fiber mat. This new approach, which does not use any fitting parameters, achieved a good validation against a previous published result on the 1D unsaturated flow in a biaxial stitched mat,satisfactory comparisons of the inlet-pressure history as well as the saturation distributions were achieved. Finally, the unsaturated flow is studied in a car hood-type LCM mold geometry using the code PORE-FLOW© based on the proposed algorithm. POLYM. COMPOS., 31:1790,1807, 2010. © 2010 Society of Plastics Engineers. [source] Analysis of the macrophage scavenger receptor 1 gene in Swedish hereditary and sporadic prostate cancerTHE PROSTATE, Issue 2 2004Fredrik Lindmark Abstract BACKGROUND The macrophage scavenger receptor 1 (MSR1) gene on chromosome 8p22 was recently reported as a candidate gene for hereditary prostate cancer (HPC). Here, we further elucidate the role of MSR1 in both Swedish families with HPC and in a cohort of unselected prostate cancer. METHODS DNA samples from 83 Swedish HPC families and 215 unselected population based cases of prostate cancer as well as 425 age-matched controls were genotyped. RESULTS A total of 18 variants were identified, including 2 exonic, 7 intronic changes, and 9 changes in the 5,- or 3,-uncoding region. Of the two exonic changes, one previously reported truncation mutation was identified, a R293X nonsense mutation. This mutation was found in 2 of the 83 (2.4%) HPC families. The R293X mutation was found more frequently in men with PC (4.9%) than in unaffected men (2.7%), consistent with previous published results, however our results were not significant (P,=,0.16). To additionally test for potential association of common sequence variants and increased risk for the disease, five common polymorphisms (PRO3, INDEL1, IVS5-57, P275A, INDEL7) were genotyped in the group of 215 prostate cancer cases and 425 age-matched controls. No association between any of the five common sequence variants and prostate cancer were found. CONCLUSION Our results suggest that mutations in MSR1 gene might play a role in prostate cancer susceptibility, particularly the R293X mutation. This study warrants further investigations of the role of MSR1 in prostate cancer etiology. © 2004 Wiley-Liss, Inc. [source] | ||||||||||