922 research outputs found
Book Reviews
Reviews of the following books: Acadia, Maine, and New Scotland: Marginal Colonies in the Seventeenth Century by John G. Reid; Faces of Maine by Bob Niss; Morning Was Starlight: My Maine Boyhood by Ernest Dodge
The amphioxus genome and the evolution of the chordate karyotype
Lancelets ('amphioxus') are the modern survivors of an ancient chordate lineage, with a fossil record dating back to the Cambrian period. Here we describe the structure and gene content of the highly polymorphic approx520-megabase genome of the Florida lancelet Branchiostoma floridae, and analyse it in the context of chordate evolution. Whole-genome comparisons illuminate the murky relationships among the three chordate groups (tunicates, lancelets and vertebrates), and allow not only reconstruction of the gene complement of the last common chordate ancestor but also partial reconstruction of its genomic organization, as well as a description of two genome-wide duplications and subsequent reorganizations in the vertebrate lineage. These genome-scale events shaped the vertebrate genome and provided additional genetic variation for exploitation during vertebrate evolution
A cardinal role for cathepsin D in co-ordinating the host-mediated apoptosis of macrophages and killing of pneumococci
The bactericidal function of macrophages against pneumococci is enhanced by their apoptotic demise, which is controlled by the anti-apoptotic protein Mcl-1. Here, we show that lysosomal membrane permeabilization (LMP) and cytosolic translocation of activated cathepsin D occur prior to activation of a mitochondrial pathway of macrophage apoptosis. Pharmacological inhibition or knockout of cathepsin D during pneumococcal infection blocked macrophage apoptosis. As a result of cathepsin D activation, Mcl-1 interacted with its ubiquitin ligase Mule and expression declined. Inhibition of cathepsin D had no effect on early bacterial killing but inhibited the late phase of apoptosis-associated killing of pneumococci in vitro. Mice bearing a cathepsin D-/- hematopoietic system demonstrated reduced macrophage apoptosis in vivo, with decreased clearance of pneumococci and enhanced recruitment of neutrophils to control pulmonary infection. These findings establish an unexpected role for a cathepsin D-mediated lysosomal pathway of apoptosis in pulmonary host defense and underscore the importance of apoptosis-associated microbial killing to macrophage function
Triple Co-Administration of Ivermectin, Albendazole and Praziquantel in Zanzibar: A Safety Study
This paper describes how the use of three drugs which are used separately in mass drug distribution programmes when given together appear safe for use in large populations which have been previously treated with the same drugs separately (Mectizan [ivermectin], albendazole and praziquantel). The target diseases—lymphatic filariasis, soil-transmitted worms and schistosomiasis—were prevalent in Zanzibar up to 2000 but have been largely controlled by mass drug administration. The Ministry of Health and Social Welfare, with the support of WHO, initiated a small scale trial in a population of triple therapy in over 5,000 people initially in two sites, and having found there were no severe adverse events associated with the combined treatment then upscaled to treat the whole of the eligible population of over 700,000. Similarly, there were no severe adverse events. This is the first time the three drugs have been used together at the same time at scale in Africa and provide a basis for expansion of integrated preventive chemotherapy of helminths (worms). The next steps need to be initiated in populations which have heavier worm loads and such interventions need to be subject to close monitoring and ethical review
Thiazolidinedione Use, Fluid Retention, and Congestive Heart Failure: A consensus statement from the American Heart Association and American Diabetes Association
"Diabetes is a chronic, progressively worsening disease associated with a variety of microvascular and macrovascular complications. Cardiovascular disease (CVD) is the main cause of death in these patients (1,2). During the past decade, numerous drugs have been introduced for the treatment of type 2 diabetes that, used in monotherapy or in combination therapy, are effective in lowering blood glucose to achieve glycemic goals and in reducing diabetes-related end-organ disease. Two such drugs, rosiglitazone and pioglitazone, belong to the class called thiazolidinediones (TZDs) (3). Troglitazone, the first agent of this class to be approved, was effective in controlling glycemia but was removed from the market because of serious liver toxicity. Both rosiglitazone and pioglitazone are indicated either as monotherapy or in combination with a sulfonylurea, metformin, or insulin when diet, exercise, and a single agent do not result in adequate glycemic control (4) (package insert Avandia [rosiglitazone maleate; GlaxoSmithKline] and Actos (5) [pioglitazone hydrochloride; Takeda Pharmaceuticals]). In addition to lowering blood glucose, both drugs may benefit cardiovascular parameters, such as lipids, blood pressure, inflammatory biomarkers, endothelial function, and fibrinolytic status (6,7). These beneficial effects of TZDs on glycemia and cardiovascular risk factors have made them attractive agents in patients with type 2 diabetes who are at high risk for CVD. There is a growing recognition, however, that edema can occur in patients treated with either drug. Because people with diabetes are at increased risk for CVD and many have preexisting heart disease, the edema that sometimes accompanies the use of a TZD can be cause for concern, as it may be a harbinger or sign of congestive heart failure (CHF). An analysis of Medicare beneficiaries hospitalized with the diagnosis of diabetes and CHF indicated that the number of these patients discharged on TZDs had increased from 7.2% to 16.2% over a 3-year period (8). As the number of patients taking these drugs to control glycemia increases, practitioners should be aware of the safety profile of TZDs in patients with and without underlying heart disease.
Thiazolidinedione Use, Fluid Retention, and Congestive Heart Failure: A Consensus Statement from the American Heart Association and American Diabetes Association
"Diabetes is a chronic, progressively worsening disease associated with a variety of microvascular and macrovascular complications. Cardiovascular disease (CVD) is the main cause of death in these patients.1,2 During the past decade, numerous drugs have been introduced for the treatment of type 2 diabetes that, used in monotherapy or in combination therapy, are effective in lowering blood glucose to achieve glycemic goals and in reducing diabetes-related end-organ disease. Two such drugs, rosiglitazone and pioglitazone, belong to the class called thiazolidinediones (TZDs).3 Troglitazone, the first agent of this class to be approved, was effective in controlling glycemia but was removed from the market because of serious liver toxicity. Both rosiglitazone and pioglitazone are indicated either as monotherapy or in combination with a sulfonylurea, metformin, or insulin when diet, exercise, and a single agent do not result in adequate glycemic control4 (package insert Avandia [rosiglitazone maleate; GlaxoSmithKline] and Actos5 [pioglitazone hydrochloride; Takeda Pharmaceuticals]). In addition to lowering blood glucose, both drugs may benefit cardiovascular parameters, such as lipids, blood pressure, inflammatory biomarkers, endothelial function, and fibrinolytic status.6,7 These beneficial effects of TZDs on glycemia and cardiovascular risk factors have made them attractive agents in patients with type 2 diabetes who are at high risk for CVD. There is a growing recognition, however, that edema can occur in patients treated with either drug. Because people with diabetes are at increased risk for CVD and many have preexisting heart disease, the edema that sometimes accompanies the use of a TZD can be cause for concern, as it may be a harbinger or sign of congestive heart failure (CHF). An analysis of Medicare beneficiaries hospitalized with the diagnosis of diabetes and CHF indicated that the number of these patients discharged on TZDs had increased from 7.2% to 16.2% over a 3-year period.8 As the number of patients taking these drugs to control glycemia increases, practitioners should be aware of the safety profile of TZDs in patients with and without underlying heart disease.
Successful up-scaled population interventions to reduce risk factors for non-communicable disease in adults: Results from the International Community Interventions for Health (CIH) project in China, India and Mexico
Background: Non-communicable disease (NCD) is increasing rapidly in low and middle-income countries (LMIC), and is associated with tobacco use, unhealthy diet and physical inactivity. There is little evidence for up-scaled interventions at the population level to reduce risk in LMIC. Methods: The Community Interventions for Health (CIH) program was a population-scale community intervention study with comparator population group undertaken in communities in China, India, and Mexico, each with populations between 150,000-250,000. Culturally appropriate interventions were delivered over 18-24 months. Two independent cross-sectional surveys of a stratified sample of adults aged 18-64 years were conducted at baseline and follow-up. Results: A total of 6,194 adults completed surveys at baseline, and 6,022 at follow-up. The proportion meeting physical activity recommendations decreased significantly in the control group (C) (44.1 to 30.2%), but not in the intervention group (I) (38.0 to 36.1%), p<0.001. Those eating ≥5 portions of fruit and vegetables daily decreased significantly in C (19.2 to 17.2%), but did not change in I (20.0 to 19.6%,), p=0.013. The proportion adding salt to food was unchanged in C (24.9 to 25.3%) and decreased in I (25.9 to 19.6%), p<0.001. Prevalence of obesity increased in C (8.3 to 11.2%), with no change in I (8.6 to 9.7%,) p=0.092. Concerning tobacco, for men the difference-in-difference analysis showed that the reduction in use was significantly greater in I compared to C (p=0.014) Conclusions: Up-scaling known health promoting interventions designed to reduce the incidence of NCD in whole communities in LMIC is feasible, and has measurable beneficial outcomes on risk factors for NCD, namely tobacco use, diet, and physical inactivity
Health Education through Analogies: Preparation of a Community for Clinical Trials of a Vaccine against Hookworm in an Endemic Area of Brazil
Conducting clinical trials of new vaccines in rural, resource-limited areas can be challenging since the people living in these areas often have high levels of illiteracy, little experience with clinical research, and limited access to routine health care. Especially difficult is obtaining informed consent for participation in this type of research and ensuring that potential participants adequately understand the potential risks and benefits of participation. The researchers have been preparing a remote field site in the northeastern part of the state of Minas Gerais, Brazil, for clinical trials of experimental hookworm vaccines. A special educational video was designed based on the method of analogies to introduce new scientific concepts related to the researchers' work and to improve knowledge of hookworm, a disease that is highly prevalent in their community. A questionnaire was administered both before and after the video was shown to a group of adults at the field site, which demonstrated the effectiveness of the video in disseminating knowledge about hookworm infection and about the vaccine being developed. Therefore, even in a rural, resource-limited area, educational tools can be specially designed that significantly improve understanding and therefore the likelihood of obtaining truly informed consent for participation in clinical research
CTL Responses of High Functional Avidity and Broad Variant Cross-Reactivity Are Associated with HIV Control
Cytotoxic T lymphocyte (CTL) responses targeting specific HIV proteins, in particular Gag, have been associated with relative control of viral replication in vivo. However, Gag-specific CTL can also be detected in individuals who do not control the virus and it remains thus unclear how Gag-specific CTL may mediate the beneficial effects in some individuals but not in others. Here, we used a 10mer peptide set spanning HIV Gag-p24 to determine immunogen-specific T-cell responses and to assess functional properties including functional avidity and cross-reactivity in 25 HIV-1 controllers and 25 non-controllers without protective HLA class I alleles. Our data challenge the common belief that Gag-specific T cell responses dominate the virus-specific immunity exclusively in HIV-1 controllers as both groups mounted responses of comparable breadths and magnitudes against the p24 sequence. However, responses in controllers reacted to lower antigen concentrations and recognized more epitope variants than responses in non-controllers. These cross-sectional data, largely independent of particular HLA genetics and generated using direct ex-vivo samples thus identify T cell responses of high functional avidity and with broad variant reactivity as potential functional immune correlates of relative HIV control
High-Density SNP Mapping of the HLA Region Identifies Multiple Independent Susceptibility Loci Associated with Selective IgA Deficiency
Selective IgA deficiency (IgAD; serum IgA<0.07 g/l) is the most common form of human primary immune deficiency, affecting approximately 1∶600 individuals in populations of Northern European ancestry. The polygenic nature of IgAD is underscored by the recent identification of several new risk genes in a genome-wide association study. Among the characterized susceptibility loci, the association with specific HLA haplotypes represents the major genetic risk factor for IgAD. Despite the robust association, the nature and location of the causal variants in the HLA region remains unknown. To better characterize the association signal in this region, we performed a high-density SNP mapping of the HLA locus and imputed the genotypes of common HLA-B, -DRB1, and -DQB1 alleles in a combined sample of 772 IgAD patients and 1,976 matched controls from 3 independent European populations. We confirmed the complex nature of the association with the HLA locus, which is the result of multiple effects spanning the entire HLA region. The primary association signal mapped to the HLA-DQB1*02 allele in the HLA Class II region (combined P = 7.69×10−57; OR = 2.80) resulting from the combined independent effects of the HLA-B*0801-DRB1*0301-DQB1*02 and -DRB1*0701-DQB1*02 haplotypes, while additional secondary signals were associated with the DRB1*0102 (combined P = 5.86×10−17; OR = 4.28) and the DRB1*1501 (combined P = 2.24×10−35; OR = 0.13) alleles. Despite the strong population-specific frequencies of HLA alleles, we found a remarkable conservation of these effects regardless of the ethnic background, which supports the use of large multi-ethnic populations to characterize shared genetic association signals in the HLA region. We also provide evidence for the location of association signals within the specific extended haplotypes, which will guide future sequencing studies aimed at characterizing the precise functional variants contributing to disease pathogenesis
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