Most types of cells in the body do not express the capability of catabolizing cholesterol, so cholesterol efflux is essential for homeostasis. For instance, macrophages possess four pathways for ...exporting free (unesterified) cholesterol to extracellular high density lipoprotein (HDL). The passive processes include simple diffusion via the aqueous phase and facilitated diffusion mediated by scavenger receptor class B, type 1 (SR-BI). Active pathways are mediated by the ATP-binding cassette (ABC) transporters ABCA1 and ABCG1, which are membrane lipid translocases. The efflux of cellular phospholipid and free cholesterol to apolipoprotein A-I promoted by ABCA1 is essential for HDL biogenesis. Current understanding of the molecular mechanisms involved in these four efflux pathways is presented in this minireview.
ABCA1 functions as a lipid transporter because it mediates the transfer of cellular phospholipid (PL) and free (unesterified) cholesterol (FC) to apoA-I and related proteins present in the ...extracellular medium. ABCA1 is a membrane PL translocase and its enzymatic activity leads to transfer of PL molecules from the cytoplasmic leaflet to the exofacial leaflet of a cell plasma membrane (PM). The presence of active ABCA1 in the PM promotes binding of apoA-I to the cell surface. About 10% of this bound apoA-I interacts directly with ABCA1 and stabilizes the transporter. Most of the pool of cell surface-associated apoA-I is bound to lipid domains in the PM that are created by the activity of ABCA1. The amphipathic α-helices in apoA-I confer detergent-like properties on the protein enabling it to solubilize PL and FC in these membrane domains to create a heterogeneous population of discoidal nascent HDL particles. This review focuses on current understanding of the structure-function relationships of human ABCA1 and the molecular mechanisms underlying HDL particle production.
Evidence is accumulating that pesticide self-poisoning is one of the most commonly used methods of suicide worldwide, but the magnitude of the problem and the global distribution of these deaths is ...unknown.
We have systematically reviewed the worldwide literature to estimate the number of pesticide suicides in each of the World Health Organisation's six regions and the global burden of fatal self-poisoning with pesticides. We used the following data sources: Medline, EMBASE and psycINFO (1990-2007), papers cited in publications retrieved, the worldwide web (using Google) and our personal collections of papers and books. Our aim was to identify papers enabling us to estimate the proportion of a country's suicides due to pesticide self-poisoning.
We conservatively estimate that there are 258,234 (plausible range 233,997 to 325,907) deaths from pesticide self-poisoning worldwide each year, accounting for 30% (range 27% to 37%) of suicides globally. Official data from India probably underestimate the incidence of suicides; applying evidence-based corrections to India's official data, our estimate for world suicides using pesticides increases to 371,594 (range 347,357 to 439,267). The proportion of all suicides using pesticides varies from 4% in the European Region to over 50% in the Western Pacific Region but this proportion is not concordant with the volume of pesticides sold in each region; it is the pattern of pesticide use and the toxicity of the products, not the quantity used, that influences the likelihood they will be used in acts of fatal self-harm.
Pesticide self-poisoning accounts for about one-third of the world's suicides. Epidemiological and toxicological data suggest that many of these deaths might be prevented if (a) the use of pesticides most toxic to humans was restricted, (b) pesticides could be safely stored in rural communities, and (c) the accessibility and quality of care for poisoning could be improved.
Specialized plant terpenoids have found fortuitous uses in medicine due to their evolutionary and biochemical selection for biological activity in animals. However, these highly functionalized ...natural products are produced through complex biosynthetic pathways for which we have a complete understanding in only a few cases. Here we review some of the most effective and promising plant terpenoids that are currently used in medicine and medical research and provide updates on their biosynthesis, natural occurrence, and mechanism of action in the body. This includes pharmacologically useful plastidic terpenoids such as
-menthane monoterpenoids, cannabinoids, paclitaxel (taxol
), and ingenol mebutate which are derived from the 2-
-methyl-d-erythritol-4-phosphate (MEP) pathway, as well as cytosolic terpenoids such as thapsigargin and artemisinin produced through the mevalonate (MVA) pathway. We further provide a review of the MEP and MVA precursor pathways which supply the carbon skeletons for the downstream transformations yielding these medically significant natural products.
Abstract Background Agricultural pesticide poisoning is a major contributor to the global burden of suicide. Over the last decade there has been a marked decrease in the incidence of suicide ...worldwide. It is unclear whether pesticide poisoning still plays a significant role in the global incidence of suicide. Methods WHO method-specific suicide data were supplemented by a systematic review of the literature between 2006 and 2015, including searches of thirteen electronic databases and Google, citation searching and a review of reference lists and personal collections. Our primary outcome was the proportion of total suicides due to pesticide poisoning. Weighted estimates were calculated for seven WHO regional and income strata. Results We identified data from 108 countries (102 from WHO data, 6 from the literature). A conservative estimate based on these data indicates that there were approximately 110,000 pesticide self-poisoning deaths each year from 2010 to 2014, comprising 13.7% of all global suicides. A sensitivity analysis accounting for under-reporting of suicides in India resulted in an increased estimate of 168,000 pesticide self-poisoning deaths annually, that is, 19.7% of global suicides. The proportion of suicides due to pesticide self-poisoning varies considerably between regions, from 0.9% in low- and middle-income countries in the European region to 48.3% in low- and middle-income countries in the Western Pacific region. Limitations High quality method-specific suicide data were unavailable for a number of the most populous countries, particularly in the African and Eastern Mediterranean regions. It is likely we have underestimated incidence in these regions. Conclusion There appears to have been a substantial decline in fatal pesticide self-poisoning in recent years, largely driven by a reduction in overall suicide rates in China. Nonetheless, pesticide self-poisoning remains a major public health challenge, accounting for at least one-in-seven suicides globally.
The unpredictability and uncertainty of the COVID-19 pandemic; the associated lockdowns, physical distancing, and other containment strategies; and the resulting economic breakdown could increase the ...risk of mental health problems and exacerbate health inequalities. Preliminary findings suggest adverse mental health effects in previously healthy people and especially in people with pre-existing mental health disorders. Despite the heterogeneity of worldwide health systems, efforts have been made to adapt the delivery of mental health care to the demands of COVID-19. Mental health concerns have been addressed via the public mental health response and by adapting mental health services, mostly focusing on infection control, modifying access to diagnosis and treatment, ensuring continuity of care for mental health service users, and paying attention to new cases of mental ill health and populations at high risk of mental health problems. Sustainable adaptations of delivery systems for mental health care should be developed by experts, clinicians, and service users, and should be specifically designed to mitigate disparities in health-care provision. Thorough and continuous assessment of health and service-use outcomes in mental health clinical practice will be crucial for defining which practices should be further developed and which discontinued. For this Position Paper, an international group of clinicians, mental health experts, and users of mental health services has come together to reflect on the challenges for mental health that COVID-19 poses. The interconnectedness of the world made society vulnerable to this infection, but it also provides the infrastructure to address previous system failings by disseminating good practices that can result in sustained, efficient, and equitable delivery of mental health-care delivery. Thus, the COVID-19 pandemic could be an opportunity to improve mental health services.
Abstract Background Previous studies in Western countries have consistently documented positive associations of smoking and heavy drinking with depressive symptoms but a prospective analysis of these ...relationships among middle-aged and elderly community members in China have not previously been reported. Methods Using data from the China Health and Retirement Longitudinal Study, a two-wave nationally representative survey conducted in 15,628 adults 45 years of age and older, we estimated the prospective association between depressive symptoms and an array of smoking and drinking behaviors. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D) short form. Results Inverse associations were the dominant pattern of association. For the population as a whole, individuals with baseline depressive symptoms were less likely to start drinking (OR=0.7, 95% CI=0.5, 0.9) or smoking (OR=0.6, 95% CI=0.4, 0.8). Similarly, baseline drinkers and smokers were less likely to develop depressive symptoms (ORdrinkers =0.6, 95% CI=0.5, 0.7; ORsmokers =0.7, 95% CJ=0.6, 0.9). No evidence was found for an increased incidence or persistence of depressive symptoms among high-frequency drinkers or heavy smokers or vice versa. Males who had never smoked prior to the onset of depressive symptoms tended to have more rapid onset of tobacco dependence compared to those without such symptoms. Males and females had different association patterns. Limitations The study is observational in nature and provides limited evidence for causality. Discussion The results are inconsistent with previous findings in Western countries, throwing into question the presumed universality of the association between alcohol drinking or tobacco use and depression among middle-aged and elderly adults.
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