760 research outputs found
Better water quality indicators for understanding microbial health risks.
The aims of the research were to evaluate existing microbial water quality indicators, and refine and/or develop alternative, improved indicators for determining the source of faecal contamination in urban and rural surface waters. There has been concern that because E. coli is capable of long term persistence in the environment in temperate climates that it is no longer a valid frontline tool for water quality monitoring. This research explored urban (untreated human sewage) and rural (cow faeces) impacts on water quality, and investigated relationships between faecal source tracking (FST) markers, faecal ageing determinants, microbial indicators and pathogens. The variables measured were FST markers (quantitative Polymerase Chain Reaction (qPCR), and faecal steroids), the faecal ageing ratio of atypical colonies/total coliforms (AC/TC), and the indicator microorganism, Escherichia coli. In the urban river study, additional determinants were indicator microorganisms, Clostridium perfringens and F-RNA phage; potential pathogens belonging to the genera of Campylobacter, Giardia and Cryptosporidium, and the FST marker, fluorescent whitening agents (FWA).
In the urban study, a river had been impacted by major discharges of untreated human sewage. Variables were monitored in the river water and underlying sediment at three locations both during discharge, and up to eighteen months post-discharge. Relationships between E. coli and potential pathogens in water demonstrated that E. coli was a reliable indicator of public health risk. As a signal of a recent human faecal input, F-RNA phage were identified as suitable, cost-effective indicators to be measured in conjunction with E. coli. In contrast, the ubiquitous C. perfringens was observed to accumulate in sediments, confounding its ability as an indicator in water. PCR markers and faecal steroids in water were similar and even superior to E. coli as predictors of protozoan pathogen presence, and hence indicative of human health risk. The faecal ageing ratio, AC/TC in water, was significantly, negatively correlated with increasing pathogen detection. Campylobacter had the weakest associations with all microbial and FST indicators. It was observed, however, that where elevated E. coli levels were detected in water, identification of the HumM3 PCR marker in conjunction with F-RNA phage and a low AC/TC ratio <1.5 was indicative of fresh pollution and an associated health risk from Campylobacter. River sediments appeared to be a reservoir for steroids and FWA, Cryptosporidium and Giardia but not Campylobacter or F-RNA phage. FST PCR markers were not assayed in the sediments. There was no relationship observed between chemical FST markers in sediments and the overlying water, and few correlations between chemical FST markers and target microorganisms in sediment.
In the rural study, the decomposition of cowpats was investigated to determine the mobilisation rates of water quality determinants when irrigated and non-irrigated cowpats were subjected to simulated flood and rainfall runoff events. It was observed that decomposing cowpats harboured concentrations of E. coli, which were available for mobilisation after flood and rainfall events for at least five and a half months post-deposition under flood conditions, and for at least two and a half months after lighter rainfall. Persistent levels of total coliforms in ageing cowpats showed that AC/TC ratios would indicate fresh sources of faecal contamination in a waterway after flood conditions up to four months post-deposition. An amplicon–based metagenomic study of the ageing cowpat investigated shifts in microbial populations as the cowpat decomposed. Major bacterial community shifts were observed over 161 days in the mobilised fraction from decomposing cowpats. Dominant bacteria that inhabited the cow rumen and fresh faeces, such as a Ruminococcus species, were displaced by bacterial groups that could be utilised as potential PCR targets of aged bovine faecal sources. Faecal steroid ratios were observed to be reliable and stable FST markers during the ageing process. The PCR marker ratio of BacR/TotalBac (ruminant (BacR)/Total Bacteroidetes) has potential as an indicator of 100% contribution from fresh bovine sources.
Recommendations for water managers are outlined for the cost-effective application of FST tools based on findings from this current research. The differential fate and transport of microbial and FST markers noted in this research supported the use of multiple lines of evidence through application of a cohort of indicators for tracking the source(s) of faecal contamination and indicating the associated public health risk. In the urban river study, strong to moderate correlations between PCR and steroid markers suggested they could be used individually or combined for greater confidence in the result. Some of the FST host-associated PCR markers (HumM3 and CowM2) were shown to be useful indicators of recent faecal inputs to a waterbody. The lack of correlation between chemical FST markers and microorganisms in sediment suggested that chemical markers in sediment were indicative of historical faecal sources, and restricted their predictive value for health risks. Due to the persistence of potential pathogens, re-suspension of sediment has the potential to increase risk to human health for those who participate in recreational and work activities in the river environment. It is suggested that where runoff from non-flood conditions may confound water quality monitoring, application of the Bacteroidales host-associated PCR markers would be preferable to the more persistent E. coli. In addition, AC/TC testing should only be performed during baseflow conditions. The sequence information generated from the cowpat metagenomic study could be used for development of a metagenomic FST library of bacteria. Mobilisation rates of FST markers from cowpat runoff determined in this rural study can contribute to models designed to apportion contamination from agricultural sources
The isolation and genotypic characterisation of campylobacter jejuni from environmental matrices
Infection by Campylobacter is the most notified gastrointestinal disease in New Zealand. Reliable recovery and identification of campylobacters is challenging. Improved and validated methods are needed to increase the power of subtyping and epidemiological studies to trace the sources and transmission routes of Campylobacter. An enrichment-PCR method for the isolation and detection of C. jejuni and C. coli was developed and sensitivity levels determined in 13 environmental matrices, including animal faeces, food and water. Less than ten cells per sample of either C. jejuni or C. coli could be detected, except for rabbit faeces where the minimum number of cells detected per sample was greater than ten cells for C. coli (range 3-32 cells). The sensitivity of the method was comparable to that determined for the conventional methods in the same matrices. Application of the method to retail chicken carcasses (n =204) determined a prevalence of 27.5% C. jejuni and 1% C. coli. River water assays (n = 293) found 55.3% of samples to contain C. jejuni and 4.1% C. coli. Furthermore, the enrichment-PCR assay was shown to identify up to three subtypes in individual water samples. It was proposed that the identification of non-dominant subtypes carried by a chicken carcass may aid the identification of subtypes implicated in human cases of campylobacteriosis. An average of twenty-three C. jejuni isolates from each of ten retail chicken carcass were subtyped by PFGE using the two restriction enzymes SmaI and KpnI. Fifteen subtypes, in total, were identified from the ten carcasses. One subtype was identified on three carcasses. Five carcasses carried a single subtype, three carcasses carried two subtypes each and two carcasses carried three subtypes each. Some of the subtypes carried by an individual carcass were shown to be clonally related raising the question of in vivo recombination events during host passage. Comparison of C. jejuni subtypes from chickens with those isolated from human clinical cases revealed three of the fifteen subtypes correlated with those from human cases. None of the minority subtypes were identified in human case isolate data, suggesting that the lack of identification of non-dominant subtypes from chicken carcasses may not hinder the investigation of campylobacteriosis outbreaks
Pharmacokinetics of Trazodone and Its Major Metabolite M-Chlorophenylpiperazine in Plasma and Brain of Rats
Sprague–Dawley rats were used as models for single trazodone administration (males), continuous administration and dose proportionality experiments (males, females, pregnant females). Plasma and brain tissue were analysed for trazodone and its active metabolite, m-chlorophenylpiperazine (m-CPP). Fetal exposure to trazodone and m-CPP was assessed and differences in their steady-state plasma concentration were sought between adult males and females. Both trazodone and m-CPP rapidly appeared in plasma and brain tissue following a single intraperitoneal trazodone dose with brain concentrations exceeding those in plasma. Plasma concentrations of m-CPP were lower than those of trazodone but exceeded them in brain tissue. Chronic administration using osmotic mini-pumps revealed a significant linear relationship between trazodone concentration in plasma and brain at steady-state (r=0.96, p\u3c0.0001). No simple relationship was found between plasma and brain tissue concentration for m-CPP. In contrast to observations following single trazodone administration, m-CPP concentrations at steady-state were lower than trazodone concentrations in brain tissue, suggesting a lack of stationarity in the disposition of trazodone over time. No significant differences in plasma or brain tissue drug concentrations relative to administered trazodone dose were observed between male and female rats, nor between pregnant and non-pregnant females. Trazodone and mCPP were both detected in fetal and placental tissues, with placenta having the highest concentrations. The data suggest that neuropharmacological studies of trazodone could yield different results depending upon the route and schedule of drug administration. Maternally administered trazodone, like many other antidepressants, is distributed to fetal tissues in rodents, reaffirming the need for caution in treating pregnant women with psychoactive drugs
Time correlation function and finite field approaches to the calculation of the fifth order Raman response in liquid xenon
The fifth order, two-dimensional Raman response in liquid xenon is calculated via a time correlation function (TCF) theory and the numerically exact finite field method. Both employ classical molecular dynamics simulations. The results are shown to be in excellent agreement, suggesting the efficacy of the TCF approach, in which the response function is written approximately in terms of a single classical multitime TCF. (c) 2006 American Institute of Physics
Development of a core outcome set (COS) for studies relating to awareness and clinical management of reduced fetal movement: study protocol
From Springer Nature via Jisc Publications RouterHistory: received 2021-03-05, accepted 2021-11-17, registration 2021-11-17, collection 2021-12, pub-electronic 2021-12-09, online 2021-12-09Publication status: PublishedFunder: Tommy's Baby Charity; doi: http://dx.doi.org/10.13039/501100000306; Grant(s): R125598Abstract: Background: Concerns regarding reduced fetal movements (RFM) are reported in 5–15% of pregnancies, and RFM are associated with adverse pregnancy outcomes including fetal growth restriction and stillbirth. Studies have aimed to improve pregnancy outcomes by evaluating interventions to raise awareness of RFM in pregnancy, such as kick counting, evaluating interventions for the clinical management of RFM, or both. However, there is not currently a core outcome set (COS) for studies of RFM. This study aims to create a COS for use in research studies that aim to raise awareness of RFM and/or evaluate interventions for the clinical management of RFM. Methods: A systematic review will be conducted, to identify outcomes used in randomised and non-randomised studies with control groups that aimed to raise awareness of RFM (for example by using mindfulness techniques, fetal movement counting, or other tools such as leaflets or mobile phone applications) and/or that evaluated the clinical management of RFM. An international Delphi consensus will then be used whereby stakeholders will rate the importance of the outcomes identified in the systematic review in (i) awareness and (ii) clinical management studies. The preliminary lists of outcomes will be discussed at a consensus meeting where one final COS for awareness and management, or two discrete COS (one for awareness and one for management), will be agreed upon. Discussion: A well-developed COS will provide researchers with the minimum set of outcomes that should be measured and reported in studies that aim to quantify the effects of interventions
Interinstitutional variations in mode of birth after a previous caesarean section : a cross-sectional study in six German hospitals
Aims: Regional and interinstitutional variations have been recognized in the increasing incidence of caesarean section. Modes of birth after previous caesarean section vary widely, ranging from elective repeat caesarean section (ERCS) and unplanned repeat caesarean section (URCS) after trial of labour to vaginal birth after caesarean section (VBAC). This study describes interinstitutional variations in mode of birth after previous caesarean section in relation to regional indicators in Germany.
Material and methods: A cross-sectional study using the birth registers of six maternity units (n=12,060) in five different German states (n=370,209). Indicators were tested by χ2 and relative deviations from regional values were expressed as relative risks and 95% confidence intervals.
Results: The percentages of women in the six units with previous caesarean section ranged from 11.9% to 15.9% (P=0.002). VBAC was planned for 36.0% to 49.8% (P=0.003) of these women, but actually completed in only 26.2% to 32.8% (P=0.66). Depending on the indicator, the units studied deviated from the regional data by up to 32% [relative risk 0.68 (0.47–0.97)] in respect of completed VBAC among all initiated VBAC.
Conclusions: There is substantial interinstitutional variation in mode of birth following previous caesarean section. This variation is in addition to regional patterns
The final follow-up plain radiograph is sufficient for clinical evaluation of polyethylene wear in total hip arthroplasty: A study of validity and reliability
Outcomes of interventions in neonatal sepsis:A systematic review of qualitative research
BackgroundWhile a systematic review exists detailing neonatal sepsis outcomes from clinical trials, there remains an absence of a qualitative systematic review capturing the perspectives of key stakeholders.ObjectivesOur aim is to identify outcomes from qualitative research on any intervention to prevent or improve the outcomes of neonatal sepsis that are important to parents, other family members, healthcare providers, policymakers, and researchers as a part of the development of a core outcome set (COS) for neonatal sepsis.Search StrategyA literature search was carried out using MEDLINE, EMBASE, CINAHL, and PsycInfo databases.Selection CriteriaPublications describing qualitative data relating to neonatal sepsis outcomes were included.Data Collection and AnalysisDrawing on the concepts of thematic synthesis, texts related to outcomes were coded and grouped. These outcomes were then mapped to the domain headings of an existing model.Main ResultsOut of 6777 records screened, six studies were included. Overall, 19 outcomes were extracted from the included studies. The most frequently reported outcomes were those in the domains related to parents, healthcare workers and individual organ systemas such as gastrointestinal system. The remaining outcomes were classified under the headings of general outcomes, miscellaneous outcomes, survival, and infection.ConclusionsThe outcomes identified in this review are different from those reported in neonatal sepsis clinical trials, thus highlighting the importance of incorporating qualitative studies into COS development to encapsulate all relevant stakeholders' perspectives.This study reviews outcomes considered important in neonatal sepsis by stakeholders such as parents and healthcare providers, aiding in developing a core outcome set (COS)
What are the most important unanswered research questions in trial retention? A James Lind Alliance Priority Setting Partnership: the PRioRiTy II (Prioritising Retention in Randomised Trials) study
Background One of the top three research priorities for the UK clinical trial community is to address the gap in evidence-based approaches to improving participant retention in randomised trials. Despite this, there is little evidence supporting methods to improve retention. This paper reports the PRioRiTy II project, a Priority Setting Partnership (PSP) that identified and prioritised unanswered questions and uncertainties around trial retention in collaboration with key stakeholders. Methods This PSP was conducted in collaboration with the James Lind Alliance, a non-profit making initiative, to support key stakeholders (researchers, patients, and the public) in jointly identifying and agreeing on priority research questions. There were three stages. (1) First an initial online survey was conducted consisting of six open-ended questions about retention in randomised trials. Responses were coded into thematic groups to create a longlist of questions. The longlist of questions was checked against existing evidence to ensure that they had not been answered by existing research. (2) An interim stage involved a further online survey where stakeholders were asked to select questions of key importance from the longlist. (3) A face-to-face consensus meeting was held, where key stakeholder representatives agreed on an ordered list of 21 unanswered research questions for methods of improving retention in randomised trials. Results A total of 456 respondents yielded 2431 answers to six open-ended questions, from which 372 questions specifically about retention were identified. Further analysis included thematically grouping all data items within answers and merging questions in consultation with the Steering Group. This produced 27 questions for further rating during the interim survey. The top 21 questions from the interim online survey were brought to a face-to-face consensus meeting in which key stakeholder representatives prioritised the order. The ‘Top 10’ of these are reported in this paper. The number one ranked question was ’What motivates a participant’s decision to complete a clinical trial?’ The entire list will be available at www.priorityresearch.ie. Conclusion The Top 10 list can inform the direction of future research on trial methods and be used by funders to guide projects aiming to address and improve retention in randomised trials
Race-associated biological differences among luminal A and basal-like breast cancers in the Carolina Breast Cancer Study
Abstract Background We examined racial differences in the expression of eight genes and their associations with risk of recurrence among 478 white and 495 black women who participated in the Carolina Breast Cancer Study Phase 3. Methods Breast tumor samples were analyzed for PAM50 subtype and for eight genes previously found to be differentially expressed by race and associated with breast cancer survival: ACOX2, MUC1, FAM177A1, GSTT2, PSPH, PSPHL, SQLE, and TYMS. The expression of these genes according to race was assessed using linear regression and each gene was evaluated in association with recurrence using Cox regression. Results Compared to white women, black women had lower expression of MUC1, a suspected good prognosis gene, and higher expression of GSTT2, PSPHL, SQLE, and TYMS, suspected poor prognosis genes, after adjustment for age and PAM50 subtype. High expression (greater than median versus less than or equal to median) of FAM177A1 and PSPH was associated with a 63% increase (hazard ratio (HR) = 1.63, 95% confidence interval (CI) = 1.09–2.46) and 76% increase (HR = 1.76, 95% CI = 1.15–2.68), respectively, in risk of recurrence after adjustment for age, race, PAM50 subtype, and ROR-PT score. Log2-transformed SQLE expression was associated with a 20% increase (HR = 1.20, 95% CI = 1.03–1.41) in recurrence risk after adjustment. A continuous multi-gene score comprised of eight genes was also associated with increased risk of recurrence among all women (HR = 1.11, 95% CI = 1.04–1.19) and among white (HR = 1.14, 95% CI = 1.03–1.27) and black (HR = 1.11, 95% CI = 1.02–1.20) women. Conclusions Racial differences in gene expression may contribute to the survival disparity observed between black and white women diagnosed with breast cancer
- …