131 research outputs found
Deriving prevalence estimates of depressive symptoms throughout middle and old age in those living in the community
BACKGROUND: There is considerable debate about the prevalence of depression in old age. Epidemiological surveys and clinical studies indicate mixed evidence for the association between depression and increasing age. We examined the prevalence of probable depression in the middle aged to the oldest old in a project designed specifically to investigate the aging process. METHODS: Community-living participants were drawn from several Australian longitudinal studies of aging that contributed to the Dynamic Analyses to Optimise Ageing (DYNOPTA) project. Different depression scales from the contributing studies were harmonized to create a binary variable that reflected "probable depression" based on existing cut-points for each harmonized scale. Weighted prevalence was benchmarked to the Australian population which could be compared with findings from the 1997 and 2007 National Surveys of Mental Health and Well-Being (NSMHWB). RESULTS: In the DYNOPTA project, females were more likely to report probable depression. This was consistent across age levels. Both NSMHWB surveys and DYNOPTA did not report a decline in the likelihood of reporting probable depression for the oldest old in comparison with mid-life. CONCLUSIONS: Inconsistency in the reports of late-life depression prevalence in previous epidemiological studies may be explained by either the exclusion and/or limited sampling of the oldest old. DYNOPTA addresses these limitations and the results indicated no change in the likelihood of reporting depression with increasing age. Further research should extend these findings to examine within-person change in a longitudinal context and control for health covariates.NHMRC (National Health and Medical Research Council of Australia
Virus-induced congenital malformations in cattle
Diagnosing the cause of bovine congenital malformations (BCMs) is challenging for bovine veterinary practitioners and laboratory diagnosticians as many known as well as a large number of not-yet reported syndromes exist. Foetal infection with certain viruses, including bovine virus diarrhea virus (BVDV), Schmallenberg virus (SBV), blue tongue virus (BTV), Akabane virus (AKAV), or Aino virus (AV), is associated with a range of congenital malformations. It is tempting for veterinary practitioners to diagnose such infections based only on the morphology of the defective offspring. However, diagnosing a virus as a cause of BCMs usually requires laboratory examination and even in such cases, interpretation of findings may be challenging due to lack of experience regarding genetic defects causing similar lesions, even in cases where virus or congenital antibodies are present. Intrauterine infection of the foetus during the susceptible periods of development, i.e. around gestation days 60–180, by BVDV, SBV, BTV, AKAV and AV may cause malformations in the central nervous system, especially in the brain. Brain lesions typically consist of hydranencephaly, porencephaly, hydrocephalus and cerebellar hypoplasia, which in case of SBV, AKAV and AV infections may be associated by malformation of the axial and appendicular skeleton, e.g. arthrogryposis multiplex congenita. Doming of the calvarium is present in some, but not all, cases. None of these lesions are pathognomonic so diagnosing a viral cause based on gross lesions is uncertain. Several genetic defects share morphology with virus induced congenital malformations, so expert advice should be sought when BCMs are encountered. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13028-015-0145-8) contains supplementary material, which is available to authorized users
Comparison of pre- and post-vaccination ovine Johne's disease prevalence using a Bayesian approach
postprintThis study was conducted to evaluate the effectiveness of GudairTM vaccine in decreasing the prevalence of shedding of Mycobacterium avium subsp. paratuberculosis (MAP) in flocks of varying initial prevalence. Thirty seven self-replacing Merino flocks from New South Wales and Victoria (Australia) that had been vaccinating lambs with GudairTM for at least five years were enrolled in the study. These flocks had been tested prior to or at commencement of vaccination using pooled faecal culture, agar gel immunodiffusion or both tests. These pre-vaccination test results were used to estimate pre-vaccination prevalence. Post-vaccination prevalence was estimated from culture of usually 7 pools of 50 sheep collected from the enrolled flocks in 2008-2009, approximately five or more years after commencement of vaccination.
A Bayesian model was developed to estimate and compare the pre- and post-vaccination prevalences for the enrolled flocks. Apparent pre- and post-vaccination prevalences for flocks were modelled as functions of the true pre- and post-vaccination prevalences, respectively, and the sensitivities and specificities of the respective diagnostic tests. Logit-normal models were specified on pre- and post-vaccination true prevalences and were then used to make inferences about the median and 90th percentile of the prevalence distributions and their differences. Priors were mostly specified based on published literature or analysis of abattoir surveillance data for this population of flocks.
The analysis found a significant decline in ovine Johne’s disease prevalence from a pre-vaccination median prevalence of 2.72% [95% probability interval (PI): 1.40; 6.86%] to a post-vaccination median prevalence of 0.72% (0.39; 1.27%). However 30 of the 37 flocks still contained sheep that were shedding MAP in their faeces. The results suggest that vaccination with Gudair™ is usually effective in reducing the prevalence of faecal shedding but the response to vaccination is variable among flocks. This approach could be implemented in similar situations to compare prevalences where information from multiple diagnostic tests with varied sensitivities and specificities is available.
Keywords: Ovine Johne’s disease; Gudair; Vaccination; Abattoir surveillance; Faecal culture; Agar gel immune-diffusion test
Comparison of pre- and post-vaccination ovine Johne's disease prevalence using a Bayesian approach
This study was conducted to evaluate the effectiveness of GudairTM vaccine in decreasing the prevalence of shedding of Mycobacterium avium subsp. paratuberculosis (MAP) in flocks of varying initial prevalence. Thirty seven self-replacing Merino flocks from New South Wales and Victoria (Australia) that had been vaccinating lambs with GudairTM for at least five years were enrolled in the study. These flocks had been tested prior to or at commencement of vaccination using pooled faecal culture, agar gel immunodiffusion or both tests. These pre-vaccination test results were used to estimate pre-vaccination prevalence. Post-vaccination prevalence was estimated from culture of usually 7 pools of 50 sheep collected from the enrolled flocks in 2008-2009, approximately five or more years after commencement of vaccination. A Bayesian model was developed to estimate and compare the pre- and post-vaccination prevalences for the enrolled flocks. Apparent pre- and post-vaccination prevalences for flocks were modelled as functions of the true pre- and post-vaccination prevalences, respectively, and the sensitivities and specificities of the respective diagnostic tests. Logit-normal models were specified on pre- and post-vaccination true prevalences and were then used to make inferences about the median and 90th percentile of the prevalence distributions and their differences. Priors were mostly specified based on published literature or analysis of abattoir surveillance data for this population of flocks. The analysis found a significant decline in ovine Johne’s disease prevalence from a pre-vaccination median prevalence of 2.72% [95% probability interval (PI): 1.40; 6.86%] to a post-vaccination median prevalence of 0.72% (0.39; 1.27%). However 30 of the 37 flocks still contained sheep that were shedding MAP in their faeces. The results suggest that vaccination with Gudair™ is usually effective in reducing the prevalence of faecal shedding but the response to vaccination is variable among flocks. This approach could be implemented in similar situations to compare prevalences where information from multiple diagnostic tests with varied sensitivities and specificities is available. Keywords: Ovine Johne’s disease; Gudair; Vaccination; Abattoir surveillance; Faecal culture; Agar gel immune-diffusion test
Risk factors for congenital chondrodystrophy of unknown origin in beef cattle herds in south-eastern Australia
A case control study was conducted on 46 farms in south eastern Australia with a recent history of congenital chondrodystrophy of unknown origin (CCUO) between 2002 and 2007. For each farm data was collected using face-to-face interviews concerning the management of case and control mobs during the gestation period in which affected calves were born. Data concerning the paddocks in which gestating cattle were maintained was also collected for analysis. Three separate multivariable models were constructed using generalised linear mixed models (GLMM). The first model was based on the dichotomous outcome of mob status (affected/not affected) and included explanatory variables for management and environment factors. The second model used a novel approach, taking into account the number of cases in affected mobs in order to utilise available data. The outcome events/ trials was used where the numerator was equal to the number of affected calves in a mob, and the denominator was equal to the total number of calves in the mob. The third model used the dichotomous outcome paddock status and included environmental and soil variables for paddocks involved with case and control mobs. Confounding for dam age and year affected was included in the mob outcome models, and random effects for paddock and farm were incorporated into the models. The birth of CCUO calves was associated with dams grazing native pastures on hilly terrain during gestation. Low levels of pasture were also associated with the outcome. The two models used for the mob outcome were similar in many respects. The events/trial model included the use of supplemental feed and an interaction term. This study demonstrates an association between a maternal nutritional disturbance and the occurrence of CCUO. Keywords: Risk factors, congenital chondrodystrophy, case control study, epidemiology, Australiafunded by Meat and Livestock Australi
Risk factors for Neospora caninum, bovine viral diarrhoea virus, and Leptospira interrogans serovar Hardjo infection in smallholder cattle and buffalo in Lao PDR
Smallholder large ruminant production in Lao People’s Democratic Republic (Laos) is characterised by low reproductive efficiency. To determine if common abortifacient bovid infectious diseases are involved, a serological investigation was conducted. Sera was collected
from stored and fresh cattle (n = 390) and buffalo (n = 130) samples from 2016–18 from,
and then examined for associations in a retrospective risk factor study of 71 herds. The sera
were assayed for antibodies to Neospora caninum, bovine viral diarrhoea virus (BVDV),
Leptospira interrogans serovar Hardjo and Brucella abortus using commercially available
enzyme-linked immunosorbent assay kits. These pathogens were detected in buffalo samples at 78.5% (95% CI 71.4–85.6), 0%, 2.3% (95% CI 0–4.9) and 0%, respectively, and in cattle at 4.4% (95% CI 2.4–6.4), 7.7% (95% CI 3.1–12.3), 12.8% (95% CI 9.5–16.1) and
0.26% (95% CI 0–0.8), respectively. Exposure of buffalo to N. caninum was positively associated with buffalo age, with a predicted seropositivity at birth of 52.8%, increasing to 97.2% by 12 years of age (p = 0.037). Exposure of cattle to L. interrogans serovar Hardjo was more
prevalent in females compared to males, was associated with higher titres of BVDV, and
was more prevalent in the wet season compared to the dry season. Exposure of cattle to
BVDV was more prevalent in males compared to females, the wet and dry seasons were
comparable, and was associated with rising antibody titres against N. caninum and L. interrogans serovar Hardjo. The risk factor survey identified that the probability of herds being N. caninum positive increased with farmer age, if farmers believed there were rodents on farm,
and if farmers weren’t aware that canids or rodents could contaminate bovid feed on their
farm. The probability of a herd being positive to L. interrogans serovar Hardjo increased on
farms where multiple cows shared the same bull, where farmers had lower husbandry
knowledge, and on farms that used water troughs. The probability of a herd being BVDV
seropositive increased with increasing herd size and increasing titres to N. caninum. The
benchmarking of bovid exposure to emerging abortifacient pathogens and identification of their risk factors potentially informs disease prevention strategies, supporting efforts to establish a biosecure beef supply for enhanced smallholder livestock productivity, public
health and food security in Laos and surrounding countries
Stereocilia-staircase spacing is influenced by myosin III motors and their cargos espin-1 and espin-like
Hair cells tightly control the dimensions of their stereocilia, which are actin-rich protrusions with graded heights that mediate mechanotransduction in the inner ear. Two members of the myosin-III family, MYO3A and MYO3B, are thought to regulate stereocilia length by transporting cargos that control actin polymerization at stereocilia tips. We show that eliminating espin-1 (ESPN-1), an isoform of ESPN and a myosin-III cargo, dramatically alters the slope of the stereocilia staircase in a subset of hair cells. Furthermore, we show that espin-like (ESPNL), primarily present in developing stereocilia, is also a myosin-III cargo and is essential for normal hearing. ESPN-1 and ESPNL each bind MYO3A and MYO3B, but differentially influence how the two motors function. Consequently, functional properties of different motor-cargo combinations differentially affect molecular transport and the length of actin protrusions. This mechanism is used by hair cells to establish the required range of stereocilia lengths within a single cell
Stereocilia-staircase spacing is influenced by myosin III motors and their cargos espin-1 and espin-like
Hair cells tightly control the dimensions of their stereocilia, which are actin-rich protrusions with graded heights that mediate mechanotransduction in the inner ear. Two members of the myosin-III family, MYO3A and MYO3B, are thought to regulate stereocilia length by transporting cargos that control actin polymerization at stereocilia tips. We show that eliminating espin-1 (ESPN-1), an isoform of ESPN and a myosin-III cargo, dramatically alters the slope of the stereocilia staircase in a subset of hair cells. Furthermore, we show that espin-like (ESPNL), primarily present in developing stereocilia, is also a myosin-III cargo and is essential for normal hearing. ESPN-1 and ESPNL each bind MYO3A and MYO3B, but differentially influence how the two motors function. Consequently, functional properties of different motor-cargo combinations differentially affect molecular transport and the length of actin protrusions. This mechanism is used by hair cells to establish the required range of stereocilia lengths within a single cell
Predicting the Need for Therapeutic Intervention and Mortality in Acute Pancreatitis: A Two-Center International Study Using Machine Learning
BackgroundCurrent approaches to predicting intervention needs and mortality have reached 65-85% accuracy, which falls below clinical decision-making requirements in patients with acute pancreatitis (AP). We aimed to accurately predict therapeutic intervention needs and mortality on admission, in AP patients, using machine learning (ML).MethodsData were obtained from three databases of patients admitted with AP: one retrospective (Chengdu) and two prospective (Liverpool and Chengdu) databases. Intervention and mortality differences, as well as potential predictors, were investigated. Univariate analysis was conducted, followed by a random forest ML algorithm used in multivariate analysis, to identify predictors. The ML performance matrix was applied to evaluate the model's performance.ResultsThree datasets of 2846 patients included 25 potential clinical predictors in the univariate analysis. The top ten identified predictors were obtained by ML models, for predicting interventions and mortality, from the training dataset. The prediction of interventions includes death in non-intervention patients, validated with high accuracy (96%/98%), the area under the receiver-operating-characteristic curve (0.90/0.98), and positive likelihood ratios (22.3/69.8), respectively. The post-test probabilities in the test set were 55.4% and 71.6%, respectively, which were considerably superior to existing prognostic scores. The ML model, for predicting mortality in intervention patients, performed better or equally with prognostic scores.ConclusionsML, using admission clinical predictors, can accurately predict therapeutic interventions and mortality in patients with AP
Stereocilia-staircase spacing is influenced by myosin III motors and their cargos espin-1 and espin-like
Hair cells tightly control the dimensions of their stereocilia, which are actin-rich protrusions with graded heights that mediate mechanotransduction in the inner ear. Two members of the myosin-III family, MYO3A and MYO3B, are thought to regulate stereocilia length by transporting cargos that control actin polymerization at stereocilia tips. We show that eliminating espin-1 (ESPN-1), an isoform of ESPN and a myosin-III cargo, dramatically alters the slope of the stereocilia staircase in a subset of hair cells. Furthermore, we show that espin-like (ESPNL), primarily present in developing stereocilia, is also a myosin-III cargo and is essential for normal hearing. ESPN-1 and ESPNL each bind MYO3A and MYO3B, but differentially influence how the two motors function. Consequently, functional properties of different motor-cargo combinations differentially affect molecular transport and the length of actin protrusions. This mechanism is used by hair cells to establish the required range of stereocilia lengths within a single cell
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