The Effect of Heat Waves on Mental Health in a Temperate Australian City

Objective: The goal of this study was to identify mental, behavioral, and cognitive disorders that may be triggered or exacerbated during heat waves, predisposing individuals to heat-related morbidity and mortality. Design: Using health outcome data from Adelaide, South Australia, for 1993–2006, we estimated the effect of heat waves on hospital admissions and mortalities attributed to mental, behavioral, and cognitive disorders. We analyzed data using Poisson regression accounting for overdispersion and controlling for season and long-term trend, and we performed threshold analysis using hockey stick regression. Results: Above a threshold of 26.7°C, we observed a positive association between ambient temperature and hospital admissions for mental and behavioral disorders. Compared with non–heat-wave periods, hospital admissions increased by 7.3% during heat waves. Specific illnesses for which admissions increased included organic illnesses, including symptomatic mental disorders ; dementia ; mood (affective) disorders ; neurotic, stress related, and somatoform disorders ; disorders of psychological development ; and senility. Mortalities attributed to mental and behavioral disorders increased during heat waves in the 65- to 74-year age group and in persons with schizophrenia, schizotypal, and delusional disorders. Dementia deaths increased in those up to 65 years of age. Conclusion: Our results suggest that episodes of extreme heat pose a salient risk to the health and well-being of the mentally ill. Relevance to Clinical or Professional Practice: Improvements in the management and care of the mentally ill need to be addressed to avoid an increase in psychiatric morbidity and mortality as heat waves become more frequent.Alana Hansen, Peng Bi, Monika Nitschke, Philip Ryan, Dino Pisaniello and Graeme Tucke

Rainfall and sentinel chicken seroconversions predict human cases of Murray Valley encephalitis in the north of Western Australia

Background Murray Valley encephalitis virus (MVEV) is a flavivirus that occurs in Australia and New Guinea. While clinical cases are uncommon, MVEV can cause severe encephalitis with high mortality. Sentinel chicken surveillance is used at many sites around Australia to provide an early warning system for risk of human infection in areas that have low population density and geographical remoteness. MVEV in Western Australia occurs in areas of low population density and geographical remoteness, resulting in logistical challenges with surveillance systems and few human cases. While epidemiological data has suggested an association between rainfall and MVEV activity in outbreak years, it has not been quantified, and the association between rainfall and sporadic cases is less clear. In this study we analysed 22 years of sentinel chicken and human case data from Western Australia in order to evaluate the effectiveness of sentinel chicken surveillance for MVEV and assess the association between rainfall and MVEV activity. Methods Sentinel chicken seroconversion, human case and rainfall data from the Kimberley and Pilbara regions of Western Australia from 1990 to 2011 were analysed using negative binomial regression. Sentinel chicken seroconversion and human cases were used as dependent variables in the model. The model was then tested against sentinel chicken and rainfall data from 2012 and 2013.Results Sentinel chicken seroconversion preceded all human cases except two in March 1993. Rainfall in the prior three months was significantly associated with both sentinel chicken seroconversion and human cases across the regions of interest. Sentinel chicken seroconversion was also predictive of human cases in the models. The model predicted sentinel chicken seroconversion in the Kimberley but not in the Pilbara, where seroconversions early in 2012 were not predicted. The latter may be due to localised MVEV activity in isolated foci at dams, which do not reflect broader virus activity in the region. Conclusions We showed that rainfall and sentinel chickens provide a useful early warning of MVEV risk to humans across endemic and epidemic areas, and that a combination of the two indicators improves the ability to assess MVEV risk and inform risk management measures

Stimulation of MMP-11 (stromelysin-3) expression in mouse fibroblasts by cytokines, collagen and co-culture with human breast cancer cell lines

BACKGROUND: Matrix metalloproteinases (MMPs) are central to degradation of the extracellular matrix and basement membrane during both normal and carcinogenic tissue remodeling. MT1-MMP (MMP-14) and stromelysin-3 (MMP-11) are two members of the MMP family of proteolytic enzymes that have been specifically implicated in breast cancer progression. Expressed in stromal fibroblasts adjacent to epithelial tumour cells, the mechanism of MT1-MMP and MMP-11 induction remains unknown. METHODS: To investigate possible mechanisms of induction, we examined the effects of a number of plausible regulatory agents and treatments that may physiologically influence MMP expression during tumour progression. Thus NIH3T3 and primary mouse embryonic fibroblasts (MEFs) were: a) treated with the cytokines IL-1β, IL-2, IL-6, IL-8 and TGF-β for 3, 6, 12, 24, and 48 hours; b) grown on collagens I, IV and V; c) treated with fibronectin, con-A and matrigel; and d) co-cultured with a range of HBC (human breast cancer) cell lines of varied invasive and metastatic potential. RESULTS: Competitive quantitative RT-PCR indicated that MMP-11 expression was stimulated to a level greater than 100%, by 48 hour treatments of IL-1β, IL-2, TGF-β, fibronectin and collagen V. No other substantial changes in expression of MMP-11 or MT1-MMP in either tested fibroblast culture, under any treatment conditions, were observed. CONCLUSION: We have demonstrated significant MMP-11 stimulation in mouse fibroblasts using cytokines, matrix constituents and HBC cell lines, and also some inhibition of MT1-MMP. Our data suggest that the regulation of these genes in the complex stromal-epithelial interactions that occur in human breast carcinoma, is influenced by several mechanisms

What's in a virus? Folk understandings of hepatitis C infection and infectiousness among injecting drug users in Kings Cross, Sydney

BACKGROUND: To explore folk understandings of blood borne virus infection and infectiousness among injecting drug users in Kings Cross, Sydney. METHODS: Observational fieldwork was conducted in Kings Cross over a four month period. In-depth interviews with 24 current injectors and 4 key informants recruited from King Cross were undertaken. RESULTS: Hepatitis C (HCV) generated different meanings from HIV. HIV was considered "the dreaded" and generated fear of infection and dire disease progression. Whereas HCV was considered non-desirable but less threatening than HIV. The risks of transmitting HCV through sharing injecting paraphernalia was poorly understood. Some believed HCV infection was linked to poor hygiene and dirty water. Jaundice was mistakenly thought to indicate HCV infection and was used to gauge infectiousness. Many were confused about their current hepatitis C serostatus. Some participants thought they had a "dormant antibody" or that they had a "mild case" of infection. Participants were unsure what this meant for their own health or for their potential to infect others. CONCLUSION: Participants displayed confusion about transmission risks for hepatitis C, conflating blood awareness and hygiene health promotion messages. Participants' reliance on the symptom of jaundice to gauge serostatus places them at risk of transmitting and contracting HCV. Participants were confused about what a positive HCV diagnosis meant for their own health and their ability to infect others. Education is needed to debunk misconceptions about jaundice and clarify medical terms such as 'antibody' at the time of diagnosis. Further clarification of messages about injecting hygiene and blood awareness are also required

Stromelysin-3 over-expression enhances tumourigenesis in MCF-7 and MDA-MB-231 breast cancer cell lines: involvement of the IGF-1 signalling pathway

BACKGROUND: Stromelysin-3 (ST-3) is over-expressed in the majority of human carcinomas including breast carcinoma. Due to its known effect in promoting tumour formation, but its impeding effect on metastasis, a dual role of ST-3 in tumour progression, depending on the cellular grade of dedifferentiation, was hypothesized. METHODS: The present study was designed to investigate the influence of ST-3 in vivo and in vitro on the oestrogen-dependent, non-invasive MCF-7 breast carcinoma cell line as well as on the oestrogen-independent, invasive MDA-MB-231 breast carcinoma cell line. Therefore an orthotopic human xenograft tumour model in nude mice, as well as a 3D matrigel cell culture system, were employed. RESULTS: Using both in vitro and in vivo techniques, we have demonstrated that over-expression of ST-3 in MCF-7 and MDA-MB-231 cells leads to both increased cell numbers and tumour volumes. This observation was dependent upon the presence of growth factors. In particular, the enhanced proliferative capacity was in MCF-7/ST-3 completely and in MDA-MB-231/ST-3 cells partially dependent on the IGF-1 signalling pathway. Microarray analysis of ST-3 over-expressing cells revealed that in addition to cell proliferation, further biological processes seemed to be affected, such as cell motility and stress response. The MAPK-pathway as well as the Wnt and PI3-kinase pathways, appear to also play a potential role. Furthermore, we have demonstrated that breast cancer cell lines of different differentiation status, as well as the non-tumourigenic cell line MCF-10A, have a comparable capability to induce endogenous ST-3 expression in fibroblasts. CONCLUSION: These data reveal that ST-3 is capable of enhancing tumourigenesis in highly differentiated "early stage" breast cancer cell lines as well as in further progressed breast cancer cell lines that have already undergone epithelial-mesenchymal transition. We propose that ST-3 induction in tumour fibroblasts leads to the stimulation of the IGF-1R pathway in carcinoma cells, thus enhancing their proliferative capacity. In addition, further different cellular processes seem to be activated by ST-3, possibly accounting for the dual role of ST-3 in tumour progression and metastasis

Strengthening field-based training in low and middle-income countries to build public health capacity: Lessons from Australia's Master of Applied Epidemiology program

BACKGROUND: The International Health Regulations (2005) and the emergence and global spread of infectious diseases have triggered a re-assessment of how rich countries should support capacity development for communicable disease control in low and medium income countries (LMIC). In LMIC, three types of public health training have been tried: the university-based model; streamed training for specialised workers; and field-based programs. The first has low rates of production and teaching may not always be based on the needs and priorities of the host country. The second model is efficient, but does not accord the workers sufficient status to enable them to impact on policy. The third has the most potential as a capacity development measure for LMIC, but in practice faces challenges which may limit its ability to promote capacity development. DISCUSSION: We describe Australia's first Master of Applied Epidemiology (MAE) model (established in 1991), which uses field-based training to strengthen the control of communicable diseases. A central attribute of this model is the way it partners and complements health department initiatives to enhance workforce skills, health system performance and the evidence-base for policies, programs and practice. SUMMARY: The MAE experience throws light on ways Australia could collaborate in regional capacity development initiatives. Key needs are a shared vision for a regional approach to integrate training with initiatives that strengthen service and research, and the pooling of human, financial and technical resources. We focus on communicable diseases, but our findings and recommendations are generalisable to other areas of public health

Evaluation of endogenous references for gene expression profiling in different tissues of the oriental fruit fly Bactrocera dorsalis (Diptera: Tephritidae)

<p>Abstract</p> <p>Background</p> <p>Quantitative real-time reverse transcriptase PCR (RT-qPCR) has been widely used for quantification of mRNA as a way to determine key genes involved in different biological processes. For accurate gene quantification analysis, normalization of RT-qPCR data is absolutely essential. To date, normalization is most frequently achieved by the use of internal controls, often referred to as reference genes. However, several studies have shown that the reference genes used for the quantification of mRNA expression can be affected by the experimental set-up or cell type resulting in variation of the expression level of these key genes. Therefore, the evaluation of reference genes is critical for gene expression profiling, which is often neglected in gene expression studies of insects. For this purpose, ten candidate reference genes were investigated in three different tissues (midgut, Malpighian tubules, and fat body) of the oriental fruit fly, <it>Bactrocera dorsalis </it>(Hendel).</p> <p>Results</p> <p>Two different programs, <it>geNorm </it>and <it>Normfinder</it>, were used to analyze the data. According to <it>geNorm</it>, α-TUB + ACT5 are the most appropriate reference genes for gene expression profiling across the three different tissues in the female flies, while ACT3 + α-TUB are considered as the best for males. Furthermore, we evaluated the stability of the candidate reference genes to determine the sexual differences in the same tissue. In the midgut and Malpighian tubules, ACT2 + α-TUB are the best choice for both males and females. However, α-TUB + ACT1 are the best pair for fat body. Meanwhile, the results calculated by <it>Normfinder </it>are quite the same as the results with <it>geNorm</it>; α-TUB is always one of the most stable genes in each sample validated by the two programs.</p> <p>Conclusions</p> <p>In this study, we validated the suitable reference genes for gene expression profiling in different tissues of <it>B. dorsalis. </it>Moreover, appropriate reference genes were selected out for gene expression profiling of the same tissues taking the sexual differences into consideration. This work not only formed a solid basis for future gene expression study in <it>B. dorsalis</it>, but also will serve as a resource to screen reference genes for gene expression studies in any other insects.</p

Alphacoronaviruses in New World Bats: Prevalence, Persistence, Phylogeny, and Potential for Interaction with Humans

Bats are reservoirs for many different coronaviruses (CoVs) as well as many other important zoonotic viruses. We sampled feces and/or anal swabs of 1,044 insectivorous bats of 2 families and 17 species from 21 different locations within Colorado from 2007 to 2009. We detected alphacoronavirus RNA in bats of 4 species: big brown bats (Eptesicus fuscus), 10% prevalence; long-legged bats (Myotis volans), 8% prevalence; little brown bats (Myotis lucifugus), 3% prevalence; and western long-eared bats (Myotis evotis), 2% prevalence. Overall, juvenile bats were twice as likely to be positive for CoV RNA as adult bats. At two of the rural sampling sites, CoV RNAs were detected in big brown and long-legged bats during the three sequential summers of this study. CoV RNA was detected in big brown bats in all five of the urban maternity roosts sampled throughout each of the periods tested. Individually tagged big brown bats that were positive for CoV RNA and later sampled again all became CoV RNA negative. Nucleotide sequences in the RdRp gene fell into 3 main clusters, all distinct from those of Old World bats. Similar nucleotide sequences were found in amplicons from gene 1b and the spike gene in both a big-brown and a long-legged bat, indicating that a CoV may be capable of infecting bats of different genera. These data suggest that ongoing evolution of CoVs in bats creates the possibility of a continued threat for emergence into hosts of other species. Alphacoronavirus RNA was detected at a high prevalence in big brown bats in roosts in close proximity to human habitations (10%) and known to have direct contact with people (19%), suggesting that significant potential opportunities exist for cross-species transmission of these viruses. Further CoV surveillance studies in bats throughout the Americas are warranted