283 research outputs found
Deprivation is associated with anxiety and stress. A population-based longitudinal household survey among Chinese adults in Hong Kong
BACKGROUND: Mental illness is a major disease burden in the world and disproportionately affects the socially disadvantaged, but studies on the longitudinal association of poverty with anxiety and stress are rare, especially in Asia. Using data from Hong Kong, we aimed to (1) assess the cross-sectional association of poverty with anxiety and stress at baseline, and (2) to examine whether baseline poverty and change in poverty status over time are associated with a subsequent change in anxiety and stress. METHODS: Data were obtained from two waves of a territory-wide longitudinal survey in Hong Kong, with sample sizes of n=1970 and n=1224 for baseline and follow-up, respectively. Poverty was measured with a Deprivation Index and income-poverty. Anxiety and stress symptoms were assessed using Chinese Depression, Anxiety and Stress Scale-21 Items. We conducted cross-sectional and longitudinal analyses on the association of poverty with anxiety and stress. OUTCOMES: Deprivation, but not income-poverty, was significantly associated with both outcomes at baseline. Increased deprivation over time was associated with greater score and increased risk of anxiety and stress. Persistent deprivation over time was associated with greater anxiety and stress, and increased risk of incident anxiety. INTERPRETATION: Deprivation could have significant independent effects on anxiety and stress, even after adjusting for the effects of income-poverty. Greater attention should be paid to deprivation in policymaking to tackle the inequalities of mental health problems, especially since stress and anxiety are precursors to more severe forms of mental illness and other comorbidities
Mode Switching Is the Major Mechanism of Ligand Regulation of InsP3 Receptor Calcium Release Channels
The inositol 1,4,5-trisphosphate (InsP3) receptor (InsP3R) plays a critical role in generation of complex Ca2+ signals in many cell types. In patch clamp recordings of isolated nuclei from insect Sf9 cells, InsP3R channels were consistently detected with regulation by cytoplasmic InsP3 and free Ca2+ concentrations ([Ca2+]i) very similar to that observed for vertebrate InsP3R. Long channel activity durations of the Sf9-InsP3R have now enabled identification of a novel aspect of InsP3R gating: modal gating. Using a novel algorithm to analyze channel modal gating kinetics, InsP3R gating can be separated into three distinct modes: a low activity mode, a fast kinetic mode, and a burst mode with channel open probability (Po) within each mode of 0.007 ± 0.002, 0.24 ± 0.03, and 0.85 ± 0.02, respectively. Channels reside in each mode for long periods (tens of opening and closing events), and transitions between modes can be discerned with high resolution (within two channel opening and closing events). Remarkably, regulation of channel gating by [Ca2+]i and [InsP3] does not substantially alter channel Po within a mode. Instead, [Ca2+]i and [InsP3] affect overall channel Po primarily by changing the relative probability of the channel being in each mode, especially the high and low Po modes. This novel observation therefore reveals modal switching as the major mechanism of physiological regulation of InsP3R channel activity, with implications for the kinetics of Ca2+ release events in cells
The perception of disability by community groups: Stories of local understanding, beliefs and challenges in a rural part of Kenya
Cultural narratives on disability have received much attention over the past few decades. In contexts of poverty, limited information and everyday challenges associated with having, or caring for someone with a disability, different understandings have emerged. A project was set up to promote disability awareness in neighborhood communities in a rural part of Kenya, using a process of reflection and education. This paper reports on the first aspect–reflection. The aim was to investigate local understanding of disability as a co-constructed concept. The research questions were: 1. What cultural beliefs shape local understanding of disability? 2. What challenges are perceived to be associated with disability? A phenomenological approach was adopted. Focus group discussions were conducted with twenty-one community groups involving 263 participants and audio-recorded. The data were transcribed and thematic analysis was carried out. Visual maps were created to illustrate any interconnections, before establishing the final conclusions. Local beliefs attributed disability to: human transgression of social conventions, particularly concerning inappropriate family relations, which invoked a curse; supernatural forces affecting the child; the will of God; unexplained events; and biomedical factors. Challenges associated with disability related to the burden of caregiving and perceived barriers to inclusion, with stress as a shared bi-product. Local understanding of disability in this rural part of Kenya demonstrated overlapping explanations and plurality of beliefs. Two possible interpretations are offered. Firstly, oscillation between explanatory lines demonstrated instability, affecting broader acceptance of disability. Secondly, and more positively, in the face of challenges, the desire to make sense of the existing situation, reflected a healthy pluralism
Escherichia coli Frameshift Mutation Rate Depends on the Chromosomal Context but Not on the GATC Content Near the Mutation Site
Different studies have suggested that mutation rate varies at different positions in the genome. In this work we analyzed if the chromosomal context and/or the presence of GATC sites can affect the frameshift mutation rate in the Escherichia coli genome. We show that in a mismatch repair deficient background, a condition where the mutation rate reflects the fidelity of the DNA polymerization process, the frameshift mutation rate could vary up to four times among different chromosomal contexts. Furthermore, the mismatch repair efficiency could vary up to eight times when compared at different chromosomal locations, indicating that detection and/or repair of frameshift events also depends on the chromosomal context. Also, GATC sequences have been proved to be essential for the correct functioning of the E. coli mismatch repair system. Using bacteriophage heteroduplexes molecules it has been shown that GATC influence the mismatch repair efficiency in a distance- and number-dependent manner, being almost nonfunctional when GATC sequences are located at 1 kb or more from the mutation site. Interestingly, we found that in E. coli genomic DNA the mismatch repair system can efficiently function even if the nearest GATC sequence is located more than 2 kb away from the mutation site. The results presented in this work show that even though frameshift mutations can be efficiently generated and/or repaired anywhere in the genome, these processes can be modulated by the chromosomal context that surrounds the mutation site
Record linked retrospective cohort study of 4.6 million people exploring ethnic variations in disease: myocardial infarction in South Asians
Background Law and policy in several countries require health services to demonstrate that they are promoting racial/ethnic equality. However, suitable and accurate data are usually not available. We demonstrated, using acute myocardial infarction, that linkage techniques can be ethical and potentially useful for this purpose.
Methods The linkage was based on probability matching. Encryption of a unique national health identifier (the Community Health Index (CHI)) ensured that information about health status and census-based ethnicity could not be ascribed to an identified individual. We linked information on individual ethnic group from the 2001 Census to Scottish hospital discharge and mortality data.
Results Overall, 94% of the 4.9 million census records were matched to a CHI record with an estimated false positive rate of less than 0.1 %, with 84.9 – 87.6% of South Asians being successfully linked. Between April 2001 and December 2003 there were 126 first episodes of acute myocardial infarction (AMI) among South Asians and 30,978 among non-South Asians. The incidence rate ratio was 1.45 (95% CI 1.17, 1.78) for South Asian compared to non-South Asian men and 1.80 (95% CI 1.31, 2.48) for South Asian women. After adjustment for age, sex and any previous admission for diabetes the hazard ratio for death following AMI was 0.59 (95% CI 0.43, 0.81), reflecting better survival among South Asians.
Conclusion The technique met ethical, professional and legal concerns about the linkage of census and health data and is transferable internationally wherever the census (or population register) contains ethnic group or race data. The outcome is a retrospective cohort study. Our results point to increased incidence rather than increased case fatality in explaining high CHD mortality rate. The findings open up new methods for researchers and health planners
Immunological properties of Oxygen-Transport Proteins: Hemoglobin, Hemocyanin and Hemerythrin
Genomic Polymorphism of the Pandemic A (H1N1) Influenza Viruses Correlates with Viral Replication, Virulence, and Pathogenicity In Vitro and In Vivo
The novel pandemic A (H1N1) virus was first identified in Mexico in April 2009 and quickly spread worldwide. Like all influenzas, the H1N1 strain-specific properties of replication, virulence, and pathogenicity are a result of the particular genomic sequence and concerted expression of multiple genes. Thus, specific mutations may support increased virulence and may be useful as biomarkers of potential threat to human health. We performed comparative genomic analysis of ten strains of the 2009 pandemic A (H1N1) influenza viruses to determine whether genotypes associated with clinical phenotypes, which ranged from mild to severe illness and up to lethal. Virus replication capacity was tested for each strain in vitro using cultured epithelial cells, while virulence and pathogenicity were investigated in vivo using the BALB/c mouse model. The results indicated that A/Sichuan/1/2009 strain had significantly higher replication ability and virulence than the other strains, and five unique non-synonymous mutations were identified in important gene-encoding sequences. These mutations led to amino acid substitutions in HA (L32I), PA (A343T), PB1 (K353R and T566A), and PB2 (T471M), and may be critical molecular determinants for replication, virulence, and pathogenicity. Our results suggested that the replication capacity in vitro and virulence in vivo of the 2009 pandemic A (H1N1) viruses were not associated with the clinical phenotypes. This study offers new insights into the transmission and evolution of the 2009 pandemic A (H1N1) virus
Data-Driven Modelling of the Inositol Trisphosphate Receptor (IPR) and its Role in Calcium-Induced Calcium Release (CICR)
We review the current state of the art of data-driven modelling of the inositol trisphosphate receptor (IPR). After explaining that the IPR plays a crucial role as a central regulator in calcium dynamics, several sources of relevant experimental data are introduced. Single ion channels are best studied by recording single-channel currents under different ligand concentrations via the patch-clamp technique. The particular relevance of modal gating, the spontaneous switching between different levels of channel activity that occur even at constant ligand concentrations, is highlighted. In order to investigate the interactions of IPRs, calcium release from small clusters of channels, so-called calcium puffs, can be used. We then present the mathematical framework common to all models based on single-channel data, aggregated continuous-time Markov models, and give a short review of statistical approaches for parameterising these models with experimental data. The process of building a Markov model that integrates various sources of experimental data is illustrated using two recent examples, the model by Ullah et al. and the “Park–Drive” model by Siekmann et al. (Biophys. J. 2012), the only models that account for all sources of data currently available. Finally, it is demonstrated that the essential features of the Park–Drive model in different models of calcium dynamics are preserved after reducing it to a two-state model that only accounts for the switching between the inactive “park” and the active “drive” modes. This highlights the fact that modal gating is the most important mechanism of ligand regulation in the IPR. It also emphasises that data-driven models of ion channels do not necessarily have to lead to detailed models but can be constructed so that relevant data is selected to represent ion channels at the appropriate level of complexity for a given application
Effect of D222G Mutation in the Hemagglutinin Protein on Receptor Binding, Pathogenesis and Transmissibility of the 2009 Pandemic H1N1 Influenza Virus
Influenza viruses isolated during the 2009 H1N1 pandemic generally lack known molecular determinants of virulence associated with previous pandemic and highly pathogenic avian influenza viruses. The frequency of the amino acid substitution D222G in the hemagglutinin (HA) of 2009 H1N1 viruses isolated from severe but not mild human cases represents the first molecular marker associated with enhanced disease. To assess the relative contribution of this substitution in virus pathogenesis, transmission, and tropism, we introduced D222G by reverse genetics in the wild-type HA of the 2009 H1N1 virus, A/California/04/09 (CA/04). A dose-dependent glycan array analysis with the D222G virus showed a modest reduction in the binding avidity to human-like (α2-6 sialylated glycan) receptors and an increase in the binding to avian-like (α2-3 sialylated glycan) receptors in comparison with wild-type virus. In the ferret pathogenesis model, the D222G mutant virus was found to be similar to wild-type CA/04 virus with respect to lethargy, weight loss and replication efficiency in the upper and lower respiratory tract. Moreover, based on viral detection, the respiratory droplet transmission properties of these two viruses were found to be similar. The D222G virus failed to productively infect mice inoculated by the ocular route, but exhibited greater viral replication and weight loss than wild-type CA/04 virus in mice inoculated by the intranasal route. In a more relevant human cell model, D222G virus replicated with delayed kinetics compared with wild-type virus but to higher titer in human bronchial epithelial cells. These findings suggest that although the D222G mutation does not influence virus transmission, it may be considered a molecular marker for enhanced replication in certain cell types.Centers for Disease Control and Prevention (U.S.)United States. National Institutes of Health (merit award R37 GM057073-13)Singapore-MIT Alliance for Research and Technolog
Wild Type and Mutant 2009 Pandemic Influenza A (H1N1) Viruses Cause More Severe Disease and Higher Mortality in Pregnant BALB/c Mice
BACKGROUND: Pregnant women infected by the pandemic influenza A (H1N1) 2009 virus had more severe disease and higher mortality but its pathogenesis is still unclear. PRINCIPAL FINDINGS: We showed that higher mortality, more severe pneumonitis, higher pulmonary viral load, lower peripheral blood T lymphocytes and antibody responses, higher levels of proinflammatory cytokines and chemokines, and worse fetal development occurred in pregnant mice than non-pregnant controls infected by either wild type (clinical isolate) or mouse-adapted mutant virus with D222G substitution in hemagglutinin. These disease-associated changes and the lower respiratory tract involvement were worse in pregnant mice challenged by mutant virus. Though human placental origin JEG-3 cell line could be infected and proinflammatory cytokines or chemokines were elevated in amniotic fluid of some mice, no placental or fetal involvement by virus were detected by culture, real-time reverse transcription polymerase chain reaction or histopathological changes. Dual immunofluorescent staining of viral nucleoprotein and type II alveolar cell marker SP-C protein suggested that the majority of infected alveolar epithelial cells were type II pneumocytes. CONCLUSION: The adverse effect of this pandemic virus on maternal and fetal outcome is largely related to the severe pulmonary disease and the indirect effect of inflammatory cytokine spillover into the systemic circulation
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