DHX9/RHA Binding to the PBS-Segment of the Genomic RNA during HIV-1 Assembly Bolsters Virion Infectivity

Cellular RNA-binding proteins incorporated into virions during human immunodeficiency virus type 1 (HIV-1) assembly promote the replication efficiency of progeny virions. Despite its critical role in bolstering virion infectivity, the molecular basis for the incorporation of DHX9/RNA helicase A (RHA) to virions remains unclear. Here, cell-based experiments demonstrate that the truncation of segments of the HIV-1 5'-untranslated region (5'-UTR) distinct from the core encapsidation sequence eliminated virion incorporation of RHA, indicating that RHA recruitment is mediated by specific interactions with the HIV-1 5'-UTR. In agreement with biological data, isothermal titration calorimetry determined that the dimer conformation of the 5'-UTR binds one RHA molecule per RNA strand, and the interaction is independent of nucleocapsid protein binding. NMR spectra employing a deuterium-labeling approach enabled resolution of the dimeric 5'-UTR in complex with the RHA N-terminal domain. The structure of the large molecular mass complex was dependent on RHA binding to a double-stranded region of the primer binding site (PBS)-segment of the 5'-UTR. A single A-to-C substitution was sufficient to disrupt biophysical conformation and attenuate virion infectivity in cell-based assays. Taken together, our studies demonstrate the structural basis for HIV-1 genomic RNA to recruit beneficial cellular cofactor to virions. The support of progeny virion infectivity by RHA is attributable to structure-dependent binding at the PBS-segment of the HIV-1 5'-UTR during virus assembly.

Acculturation is associated with left ventricular mass in a multiethnic sample: the Multi-Ethnic Study of Atherosclerosis

Background

Acculturation involves stress-related processes and health behavioral changes, which may have an effect on left ventricular (LV) mass, a risk factor for cardiovascular disease (CVD). We examined the relationship between acculturation and LV mass in a multiethnic cohort of White, African-American, Hispanic and Chinese subjects.

Methods

Cardiac magnetic resonance assessment was available for 5004 men and women, free of clinical CVD at baseline. Left ventricular mass index was evaluated as LV mass indexed by body surface area. Acculturation was characterized based on language spoken at home, place of birth and length of stay in the United States (U.S.), and a summary acculturation score ranging from 0 = least acculturated to 5 = most acculturated. Mean LV mass index adjusted for traditional CVD risk factors was compared across acculturation levels.

Results

Unadjusted mean LV mass index was 78.0 ± 16.3 g/m². In adjusted analyses, speaking exclusively English at home compared to non-English language was associated with higher LV mass index (81.3 ± 0.4 g/m² vs 79.9 ± 0.5 g/m², p = 0.02). Among foreign-born participants, having lived in the U.S. for ≥ 20 years compared to < 10 years was associated with greater LV mass index (81.6 ± 0.7 g/m² vs 79.5 ± 1.1 g/m², p = 0.02). Compared to those with the lowest acculturation score, those with the highest score had greater LV mass index (78.9 ± 1.1 g/m² vs 81.1 ± 0.4 g/m², p = 0.002). There was heterogeneity in which measure of acculturation was associated with LV mass index across ethnic groups.

Conclusions

Greater acculturation is associated with increased LV mass index in this multiethnic cohort. Acculturation may involve stress-related processes as well as behavioral changes with a negative effect on cardiovascular health.

Trends in survival for teenagers and young adults with cancer in the UK 1992-2006

Background

Although relatively rare, cancer in teenagers and young adults (TYA) is the most common disease-related cause of death and makes a major contribution to years of life lost in this age group. There is a growing awareness of the distinctive needs of this age group and drive for greater understanding of how outcomes can be improved. We present here the latest TYA survival trends data for the United Kingdom (UK).

Methods

Using national cancer registry data, we calculated five-year relative survival for all 15–24 year olds diagnosed with cancer or a borderline/benign CNS tumour in the UK during the periods 1992–1996, 1997–2001 and 2002–2006. We analysed trends in survival for all cancers combined and for eighteen specified groups that together represent the majority of TYA cancers. We compared our data with published data for Europe, North America and Australia.

Results

Five-year survival for all cancers combined increased from 75.5% in 1992–1996 to 82.2% in 2002–2006 (P < 0.001). Statistically significant improvements were seen for all disease groups except osteosarcoma, rhabdomyosarcoma, non-gonadal and ovarian germ cell tumours and ovarian and thyroid carcinomas. During the earliest time period, females had significantly better survival than males for five of the twelve non-gender-specific disease groups. By the latest period, only melanomas and non-rhabdomyosarcoma soft tissue sarcomas had differential survival by gender. Survival in the UK for the most recent period was generally similar to other comparable countries.

Conclusion

Five-year survival has improved considerably in the UK for most cancer types. For some disease groups, there has been little progress, either because survival already approaches 100% (e.g. thyroid carcinomas) or, more worryingly for some cancers with poor outcomes, because they remain resistant to existing therapy (e.g. rhabdomyosarcoma). In addition, for a number of specific cancer types and for cancer as a whole males continue to have worse outcomes than females.

Development of Autoimmune-Mediated β Cell Failure After Total Pancreatectomy With Autologous Islet Transplantation

Total pancreatectomy with islet autotransplantation (TPIAT) is performed for definitive treatment of chronic pancreatitis; patients are not diabetic before surgery, or have C-peptide positive pancreatogenous diabetes. Thus, TPIAT recipients are not traditionally considered at risk for autoimmune loss of the islet graft. We describe a 43-year-old female who underwent TPIAT with high mass islet graft of 6031 IEQ/kg, with no evidence of presurgical β cell autoimmunity who developed type 1 diabetes within the first year after TPIAT, resulting in complete loss of beta cell function. The patient had positive GAD and insulin autoantibodies at 1 year and 18 months after TPIAT, not present prior, and undetectable C-peptide after mixed meal and intravenous glucose tolerance testing at 18 months. Glucagon secretion was preserved, suggesting the transplanted alpha cell mass was intact. HLA typing revealed a DR3/DR4 class II haplotype. This case highlights the need to consider de novo type 1 diabetes in patients with unexpected islet graft failure after TPIAT.

The hidden practices and experiences of healthcare practitioners dealing with fuel poverty

BACKGROUND

Fuel poverty negatively impacts a population's health affecting life chances along the life course. Moreover, it represents a substantial inequality in the UK. Healthcare practitioners (HCPs) have a key role in identifying and supporting patients who are fuel poor.

METHODS

A qualitative inquiry with District Nurses and General Practitioners, to explore their understanding and experiences of dealing with patients living in fuel poverty.

RESULTS

Participants recognize fuel poverty by observing material cues. They perceive their relationship with the patient as pivotal to recognizing the fuel poor. Practitioners' sense of responsibility for their patients' social concerns is determined by their knowledge about the link to health outcomes. The services that they sign-post to are motivated by their experience dealing with the service, or their patients' experiences of the service.

CONCLUSION

Participants' reliance on temporary material cues resulted in few experiences of recognition of the fuel poor. HCPs' perceptions of patient pride and the lack of personal relationship between doctor and patient presented barriers to identifying fuel poor patients. A limitation of this study is the small sample size of nine participants. These came from two professional groups, which afforded more depth of exploration, but may limit applicability to other professionals.

Global, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013

BACKGROUND

Up-to-date evidence on levels and trends for age-sex-specific all-cause and cause-specific mortality is essential for the formation of global, regional, and national health policies. In the Global Burden of Disease Study 2013 (GBD 2013) we estimated yearly deaths for 188 countries between 1990, and 2013. We used the results to assess whether there is epidemiological convergence across countries.

METHODS

We estimated age-sex-specific all-cause mortality using the GBD 2010 methods with some refinements to improve accuracy applied to an updated database of vital registration, survey, and census data. We generally estimated cause of death as in the GBD 2010. Key improvements included the addition of more recent vital registration data for 72 countries, an updated verbal autopsy literature review, two new and detailed data systems for China, and more detail for Mexico, UK, Turkey, and Russia. We improved statistical models for garbage code redistribution. We used six different modelling strategies across the 240 causes; cause of death ensemble modelling (CODEm) was the dominant strategy for causes with sufficient information. Trends for Alzheimer's disease and other dementias were informed by meta-regression of prevalence studies. For pathogen-specific causes of diarrhoea and lower respiratory infections we used a counterfactual approach. We computed two measures of convergence (inequality) across countries: the average relative difference across all pairs of countries (Gini coefficient) and the average absolute difference across countries. To summarise broad findings, we used multiple decrement life-tables to decompose probabilities of death from birth to exact age 15 years, from exact age 15 years to exact age 50 years, and from exact age 50 years to exact age 75 years, and life expectancy at birth into major causes. For all quantities reported, we computed 95% uncertainty intervals (UIs). We constrained cause-specific fractions within each age-sex-country-year group to sum to all-cause mortality based on draws from the uncertainty distributions.

FINDINGS

Global life expectancy for both sexes increased from 65.3 years (UI 65.0-65.6) in 1990, to 71.5 years (UI 71.0-71.9) in 2013, while the number of deaths increased from 47.5 million (UI 46.8-48.2) to 54.9 million (UI 53.6-56.3) over the same interval. Global progress masked variation by age and sex: for children, average absolute differences between countries decreased but relative differences increased. For women aged 25-39 years and older than 75 years and for men aged 20-49 years and 65 years and older, both absolute and relative differences increased. Decomposition of global and regional life expectancy showed the prominent role of reductions in age-standardised death rates for cardiovascular diseases and cancers in high-income regions, and reductions in child deaths from diarrhoea, lower respiratory infections, and neonatal causes in low-income regions. HIV/AIDS reduced life expectancy in southern sub-Saharan Africa. For most communicable causes of death both numbers of deaths and age-standardised death rates fell whereas for most non-communicable causes, demographic shifts have increased numbers of deaths but decreased age-standardised death rates. Global deaths from injury increased by 10.7%, from 4.3 million deaths in 1990 to 4.8 million in 2013; but age-standardised rates declined over the same period by 21%. For some causes of more than 100,000 deaths per year in 2013, age-standardised death rates increased between 1990 and 2013, including HIV/AIDS, pancreatic cancer, atrial fibrillation and flutter, drug use disorders, diabetes, chronic kidney disease, and sickle-cell anaemias. Diarrhoeal diseases, lower respiratory infections, neonatal causes, and malaria are still in the top five causes of death in children younger than 5 years. The most important pathogens are rotavirus for diarrhoea and pneumococcus for lower respiratory infections. Country-specific probabilities of death over three phases of life were substantially varied between and within regions.

INTERPRETATION

For most countries, the general pattern of reductions in age-sex specific mortality has been associated with a progressive shift towards a larger share of the remaining deaths caused by non-communicable disease and injuries. Assessing epidemiological convergence across countries depends on whether an absolute or relative measure of inequality is used. Nevertheless, age-standardised death rates for seven substantial causes are increasing, suggesting the potential for reversals in some countries. Important gaps exist in the empirical data for cause of death estimates for some countries; for example, no national data for India are available for the past decade.

FUNDING

Bill & Melinda Gates Foundation.

[The cost-utility ratio of reducing salt intake and its impact on the incidence of cardiovascular disease in Argentina]

OBJECTIVE

Estimate the cost-utility ratio of an intervention to reduce dietary salt intake in people over the age of 35 in Argentina.

METHODS

The intervention consisted of reducing salt content in food by 5% to 25%. A simulation model was used to measure the impact of policies on heart disease in order to predict incidence, prevalence, mortality, and cost trends for heart and cerebrovascular disease in the population aged 35 - 84. The intervention modeled the impact and costs of a 3-gram reduction in dietary salt intake by reducing the amount of salt in processed food and salt added to food by the participants themselves over a 10-year period. Changes in event occurrence during this period and gains in quality-adjusted life years (QALY) were estimated in high- and low-impact scenarios.

RESULTS

The intervention generated a net savings of US$ 3 765 million and a gain of 656 657 QALYs in the high-impact scenario and a savings of US$ 2 080 million and 401 659 QALY in the low-impact scenario. The result would be reductions in the incidence of heart disease (24.1%), acute myocardial infarction (21.6%), and stroke (20.5%), as well as in mortality from heart disease (19.9%) and all causes (6.4%). Benefits were observed for all age groups and both genders.

CONCLUSIONS

Implementing this strategy to reduce salt intake would produce a very positive health impact, both in QALY gains and savings in economic resources.

The epidemiology of cardiovascular diseases in sub-Saharan Africa: the Global Burden of Diseases, Injuries and Risk Factors 2010 Study

The epidemiology of cardiovascular diseases in sub-Saharan Africa is unique among world regions, with about half of cardiovascular diseases (CVDs) due to causes other than atherosclerosis. CVD epidemiology data are sparse and of uneven quality in sub-Saharan Africa. Using the available data, the Global Burden of Diseases, Risk Factors, and Injuries (GBD) 2010 Study estimated CVD mortality and burden of disease in sub-Saharan Africa in 1990 and 2010. The leading CVD cause of death and disability in 2010 in sub-Saharan Africa was stroke; the largest relative increases in CVD burden between 1990 and 2010 were in atrial fibrillation and peripheral arterial disease. CVD deaths constituted only 8.8% of all deaths and 3.5% of all disability-adjusted life years (DALYs) in sub-Sahara Africa, less than a quarter of the proportion of deaths and burden attributed to CVD in high income regions. However, CVD deaths in sub-Saharan Africa occur at younger ages on average than in the rest of the world. It remains uncertain if increased urbanization and life expectancy in some parts of sub-Saharan African nations will transition the region to higher CVD burden in future years.

Abstract 616: The Population Impact and Cost-Effectiveness of Blood Pressure Treatment in U.S. Adults Age 75 and Older

Introduction: In the next 30 years, the population of adults 75 years and older will more than double in the U.S., and high blood pressure is the most prevalent cardiovascular risk factor in this population. The impact of strategies for blood pressure control has not been evaluated in this population with special consideration of geriatric conditions that may alter the cost-effectiveness.

Methods: Based on the Cardiovascular Disease Policy Model, a Markov model of the U.S. population, we forecasted the population impact of blood pressure treatment over 10 years in adults aged 75-94 years, using the health care system perspective, and assuming an annual discount rate of 3%. Based on epidemiologic and trial data, we projected the impact of four potential negative events on cost-effectiveness in this geriatric population: 1) mild side effects, 2) polypharmacy (use of 5+ medications) associated cognitive impairment, 3) increased risk of falls/fracture, and 4) attenuated effectiveness of therapy in frail older adults

Results: We project that treatment to a systolic blood pressure target of 160 mmHg would result in the prevention of 65,000 cases of incident coronary artery disease, and 54,000 cases of incident ischemic stroke in adults 74-95 years. Based on a systolic blood pressure target of 140 mmHg, 191,000 cases of incident coronary artery disease, and 141,000 cases of incident ischemic stroke would be avoided. This would result in 729,000 additional years of life and 992,000 quality-adjusted life years (QALYs). The total health care costs of treating 75-94 year olds to a systolic blood pressure target of 140 mmHg would be $40.5 billion in the U.S., and the cost per QALY would be $40,800. The cost-effectiveness of treatment to a target of 140 mmHg would be worse in the presence of side effects ($ 51,000/QALY), polypharmacy ($ 58,400), fractures ($ 48,400), or frailty ($134,300).

Conclusions: Treatment of systolic blood pressure to a target of 140 mmHg would prevent the most cardiovascular events and result in the greatest QALYs gained. The presence of side effects, polypharmacy-related cognitive impairment, fractures, or frailty could substantially offset this benefit. Treatment strategies that are tailored to the health status of older adults are warranted.