50 research outputs found

    Neuroprotective effects of lutein in a rat model of retinal detachment

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    Background: Retinal detachment (RD) is a leading cause of blindness, and although final surgical re-attachment rate has greatly improved, visual outcome in many macula-off detachments is disappointing, mainly because of photoreceptor cell death. We previously showed that lutein is anti-apoptotic in rodent models of ischemia/reperfusion injury. The objective of this study is to investigate lutein as a possible pharmacological adjunct to surgery. Methods: Subretinal injections of 1.4 % sodium hyaluronate were used to induce RD in Sprague-Dawley rats until their retinae were approximately 70 % detached. Daily injections of corn oil (control group) or 0.5 mg/kg lutein in corn oil (treatment group) were given intraperitoneally starting 4 h after RD induction. Animals were euthanized 3 days and 30 days after RD and their retinae were analyzed for photoreceptor apoptosis and cell survival at the outer nuclear layer (ONL) using TUNEL staining and cell counting on retinal sections. Glial fibrillary acidic protein (GFAP) and rhodopsin (RHO) expression were evaluated with immunohistochemistry. Western blotting was done with antibodies against cleaved caspase-3, cleaved caspase-8 and cleaved caspase-9 to delineate lutein's mechanism of action in the apoptotic cascade. To seek a possible therapeutic time window, the same set of experiments was repeated with treatment commencing 36 h after RD. Results: When lutein was given 4 h after RD, there were significantly fewer TUNEL-positive cells in ONL 3 days after RD when compared with the vehicle group. Cell counting showed that there were significantly more nuclei in ONL in lutein-treated retinae by day 30. Treatment groups also showed significantly reduced GFAP immunoreactivity and preserved RHO expression. At day 3 after RD, Western blotting showed reduced expression of cleaved caspase-3 and cleaved caspase-8 in the treatment group. No difference was found for cleaved caspase-9. When lutein was given 36 h after RD similar results were observed. Conclusions: Our results suggest that lutein is a potent neuroprotective agent that can salvage photoreceptors in rats with RD, with a therapeutic window of at least 36 h. The use of lutein in patients with RD may serve as an adjunct to surgery to improve visual outcomes. © 2012 The Author(s).published_or_final_versio

    Phylogenetic evidence for homologous recombination within the family Birnaviridae

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    Birnaviruses are bi-segmented double-stranded RNA (dsRNA) viruses infecting insects, avian species and a wide range of aquatic species. Although homologous recombination is a common phenomenon in positive-sense RNA viruses, recombination in dsRNA viruses is rarely reported. Here we performed a comprehensive survey on homologous recombination in all available sequences (>1800) of the family Birnaviridae based on phylogenetic incongruence. Although inter-species recombination was not evident, potential intra-species recombination events were detected in aquabirnaviruses and infectious bursal disease virus (IBDV). Eight potential recombination events were identified and the possibility that these events were non-naturally occurring was assessed case by case. Five of the eight events were identified in IBDVs and all of these five events involved live attenuated vaccine strains. This finding suggests that homologous recombination between vaccine and wild-type IBDV strains may have occurred; the potential risk of mass vaccination using live vaccines is discussed. This is the first report of evidence for homologous recombination within the family Birnaviridae. © 2008 SGM.published_or_final_versio

    Experience of South and Southeast Asian minority women in Hong Kong during COVID-19 pandemic: a qualitative study

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    BACKGROUND: Hong Kong has a relatively low incidence rate of COVID-19 across the globe. Nevertheless, ethnic minorities in Hong Kong, especially South Asians (SAs) and Southeast Asians (SEAs), face numerous physical, mental, social, economic, cultural and religious challenges during the pandemic. This study explores the experiences of SA and SEA women in a predominantly Chinese metropolitan city. METHODS: Ten SA and SEA women were recruited and face-to-face interviews were conducted. Questions about participants’ daily life experience, physical and mental health conditions, economic situation and social interaction amid COVID-19 pandemic were asked to assess the impact of COVID-19. RESULTS: SAs and SEAs have a distinctive family culture, and women experienced significant physical and mental impact of COVID-19 due to their unique gender role in the family. In addition to taking care of their family in Hong Kong, SA and SEA women also had to mentally and financially support family members residing in their home countries. Access to COVID-related information was restricted due to language barrier. Public health measures including social distancing imposed extra burden on ethnic minorities with limited social and religious support. CONCLUSIONS: Even when COVID-19 incidence rate is relatively low in Hong Kong, the pandemic made life even more challenging for SAs and SEAs, which is a community already struggling with language barriers, financial woes, and discrimination. This in turn could have led to greater health inequalities. Government and civil organizations should take the social determinants of health inequalities into account when implementing COVID-19-related public health policies and strategies

    Laboratory selection for an accelerated mosquito sexual development rate

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    <p>Abstract</p> <p>Background</p> <p>Separating males and females at the early adult stage did not ensure the virginity of females of <it>Anopheles arabiensis </it>(Dongola laboratory strain), whereas two years earlier this method had been successful. In most mosquito species, newly emerged males and females are not able to mate successfully. For anopheline species, a period of 24 h post-emergence is generally required for the completion of sexual maturation, which in males includes a 180° rotation of the genitalia. In this study, the possibility of an unusually shortened sexual maturity period in the laboratory-reared colony was investigated.</p> <p>Methods</p> <p>The effect of two different sex-separation methods on the virginity of females was tested: females separated as pupae or less than 16 h post-emergence were mated with males subjected to various doses of radiation. T-tests were performed to compare the two sex-separation methods. The rate of genitalia rotation was compared for laboratory-reared and wild males collected as pupae in Dongola, Sudan, and analysed by Z-tests. Spermatheca dissections were performed on females mated with laboratory-reared males to determine their insemination status.</p> <p>Results</p> <p>When the sex-separation was performed when adults were less than 16 h post-emergence, expected sterility was never reached for females mated with radio-sterilized males. Expected sterility was accomplished only when sexes were separated at the pupal stage. Observation of genitalia rotation showed that some males from the laboratory strain Dongola were able to successfully mate only 11 h after emergence and 42% of the males had already completed rotation. A small proportion of the same age females were inseminated. Wild males showed a much slower genitalia rotation rate. At 17 h post-emergence, 96% of the laboratory-reared males had completed genitalia rotation whereas none of the wild males had.</p> <p>Conclusion</p> <p>This colony has been cultured in the laboratory for over one hundred generations, and now has accelerated sexual maturation when compared with the wild strain. This outcome demonstrates the kinds of selection that can be expected during insect colonization and maintenance, particularly when generations are non-overlapping and similar-age males must compete for mates.</p

    Global migration of influenza A viruses in swine

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    The complex and unresolved evolutionary origins of the 2009 H1N1 influenza pandemic exposed major gaps in our knowledge of the global spatial ecology and evolution of influenza A viruses in swine (swIAVs). Here we undertake an expansive phylogenetic analysis of swIAV sequence data and demonstrate that the global live swine trade strongly predicts the spatial dissemination of swIAVs, with Europe and North America acting as sources of viruses in Asian countries. In contrast, China has the world's largest swine population but is not a major exporter of live swine, and is not an important source of swIAVs in neighbouring Asian countries or globally. A meta-population simulation model incorporating trade data predicts that the global ecology of swIAVs is more complex than previously thought, and the United States and China's large swine populations are unlikely to be representative of swIAV diversity in their respective geographic regions, requiring independent surveillance efforts throughout Latin America and Asia.status: publishe

    The Inheritance of a Black Body Mutant of Biosteres longicaudatus (Hymenoptera: Braconidae) from Hawaii

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    A black body mutant, bl-b. of the braconid parasitoid, Biosteres longicaudatus (Ashmead), is described. The inheritance pattern indicates that the trait is determined by a single recessive gene
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