801 resultados para Human T-lymphotropic virus type 2 (HTLV-2)


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Human immunodeficiency virus type 1 (HIV-1) variants resistant to protease (PR) and reverse transcriptase (RT) inhibitors may display impaired infectivity and replication capacity. The individual contributions of mutated HIV-1 PR and RT to infectivity, replication, RT activity, and protein maturation (herein referred to as "fitness") in recombinant viruses were investigated by separately cloning PR, RT, and PR-RT cassettes from drug-resistant mutant viral isolates into the wild-type NL4-3 background. Both mutant PR and RT contributed to measurable deficits in fitness of viral constructs. In peripheral blood mononuclear cells, replication rates (means +/- standard deviations) of RT recombinants were 72.5% +/- 27.3% and replication rates of PR recombinants were 60.5% +/- 33.6% of the rates of NL4-3. PR mutant deficits were enhanced in CEM T cells, with relative replication rates of PR recombinants decreasing to 15.8% +/- 23.5% of NL4-3 replication rates. Cloning of the cognate RT improved fitness of some PR mutant clones. For a multidrug-resistant virus transmitted through sexual contact, RT constructs displayed a marked infectivity and replication deficit and diminished packaging of Pol proteins (RT content in virions diminished by 56.3% +/- 10.7%, and integrase content diminished by 23.3% +/- 18.4%), a novel mechanism for a decreased-fitness phenotype. Despite the identified impairment of recombinant clones, fitness of two of the three drug-resistant isolates was comparable to that of wild-type, susceptible viruses, suggestive of extensive compensation by genomic regions away from PR and RT. Only limited reversion of mutated positions to wild-type amino acids was observed for the native isolates over 100 viral replication cycles in the absence of drug selective pressure. These data underscore the complex relationship between PR and RT adaptive changes and viral evolution in antiretroviral drug-resistant HIV-1.

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The collection of dried blood spots (DBS) on filter paper provides a powerful approach for the development of large-scale, population-based screening programs. DBS methods are particularly valuable in developing countries and isolated rural regions where resources are limited. Large numbers of field specimens can be economically collected and shipped to centralized reference laboratories for genetic and (or) serological analysis. Alternatively, the dried blood can be stored and used as an archival resource to rapidly establish the frequency and distribution of newly recognized mutations, confirm patient identity or track the origins and emergence of newly identified pathogens. In this report, we describe how PCR-based technologies are beginning to interface with international screening programmes for the diagnosis and genetic characterization of human immunodeficiency virus type 1 (HIV-1). In particular, we review recent progress using DBS specimens to resolve the HIV-1 infection status of neonates, monitor the genetic evolution of HIV-1 during early infancy and establish a sentinel surveillance system for the systematic monitoring of HIV-1 genetic variation in Asia.

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It is anticipated that one out of 3 children born in the year 2000 in the United States may develop diabetes. In Switzerland, a population based study in the city of Lausanne (CoLaus) has shown that about 30% of the participants have abnormal glucose homeostasis, and that the prevalence of obesity in the younger age groups has doubled since 1992. In this review, we describe clinical and biological factors associated with an increased risk to develop diabetes and summarize the most important intervention studies that have shown a beneficial effect in the prevention of diabetes. While life style modifications should be recommended for everybody, the place of pharmacological interventions (oral hypoglycemic agents, blood pressure and cholesterol lowering agents) is more controversial.

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To compare in the Swiss population the results of several scores estimating the risk of developing type 2 diabetes. This was a single-center, cross-sectional study conducted between 2003 and 2006 in Lausanne, Switzerland. Overall, 3,251 women and 2,937 men, aged 35-75 years, were assessed, of which 5,760 (93%) were free from diabetes and included in the current study. The risk of developing type 2 diabetes was assessed using seven different risk scores, including clinical data with or without biological data. Participants were considered to be eligible for primary prevention according to the thresholds provided for each score. The results were then extrapolated to the Swiss population of the same sex and age. The risk of developing type 2 diabetes increased with age in all scores. The prevalence of participants at high risk ranged between 1.6 and 24.9% in men and between 1.1 and 15.7% in women. Extrapolated to the Swiss population of similar age, the overall number of participants at risk, and thus susceptible to intervention, ranged between 46,708 and 636,841. In addition, scores that included the same clinical variables led to a significantly different prevalence of participants at risk (4.2% [95% CI 3.4-5.0] vs. 12.8% [11.5-14.1] in men and 2.9% [2.4-3.6] vs. 6.0% [5.2-6.9] in women). CONCLUSIONS; The prevalence of participants at risk for developing type 2 diabetes varies considerably according to the scoring system used. To adequately prevent type 2 diabetes, risk-scoring systems must be validated for each population considered.

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BACKGROUND: Socioeconomic adversity in early life has been hypothesized to "program" a vulnerable phenotype with exaggerated inflammatory responses, so increasing the risk of developing type 2 diabetes in adulthood. The aim of this study is to test this hypothesis by assessing the extent to which the association between lifecourse socioeconomic status and type 2 diabetes incidence is explained by chronic inflammation. METHODS AND FINDINGS: We use data from the British Whitehall II study, a prospective occupational cohort of adults established in 1985. The inflammatory markers C-reactive protein and interleukin-6 were measured repeatedly and type 2 diabetes incidence (new cases) was monitored over an 18-year follow-up (from 1991-1993 until 2007-2009). Our analytical sample consisted of 6,387 non-diabetic participants (1,818 women), of whom 731 (207 women) developed type 2 diabetes over the follow-up. Cumulative exposure to low socioeconomic status from childhood to middle age was associated with an increased risk of developing type 2 diabetes in adulthood (hazard ratio [HR]202;=202;1.96, 95% confidence interval: 1.48-2.58 for low cumulative lifecourse socioeconomic score and HR202;=202;1.55, 95% confidence interval: 1.26-1.91 for low-low socioeconomic trajectory). 25% of the excess risk associated with cumulative socioeconomic adversity across the lifecourse and 32% of the excess risk associated with low-low socioeconomic trajectory was attributable to chronically elevated inflammation (95% confidence intervals 16%-58%). CONCLUSIONS: In the present study, chronic inflammation explained a substantial part of the association between lifecourse socioeconomic disadvantage and type 2 diabetes. Further studies should be performed to confirm these findings in population-based samples, as the Whitehall II cohort is not representative of the general population, and to examine the extent to which social inequalities attributable to chronic inflammation are reversible. Please see later in the article for the Editors' Summary.

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Guidance issued by The Department of Health, Social Services & Public Safety & The Police Service for Northern Ireland

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Retroelements are important evolutionary forces but can be deleterious if left uncontrolled. Members of the human APOBEC3 family of cytidine deaminases can inhibit a wide range of endogenous, as well as exogenous, retroelements. These enzymes are structurally organized in one or two domains comprising a zinc-coordinating motif. APOBEC3G contains two such domains, only the C terminal of which is endowed with editing activity, while its N-terminal counterpart binds RNA, promotes homo-oligomerization, and is necessary for packaging into human immunodeficiency virus type 1 (HIV-1) virions. Here, we performed a large-scale mutagenesis-based analysis of the APOBEC3G N terminus, testing mutants for (i) inhibition of vif-defective HIV-1 infection and Alu retrotransposition, (ii) RNA binding, and (iii) oligomerization. Furthermore, in the absence of structural information on this domain, we used homology modeling to examine the positions of functionally important residues and of residues found to be under positive selection by phylogenetic analyses of primate APOBEC3G genes. Our results reveal the importance of a predicted RNA binding dimerization interface both for packaging into HIV-1 virions and inhibition of both HIV-1 infection and Alu transposition. We further found that the HIV-1-blocking activity of APOBEC3G N-terminal mutants defective for packaging can be almost entirely rescued if their virion incorporation is forced by fusion with Vpr, indicating that the corresponding region of APOBEC3G plays little role in other aspects of its action against this pathogen. Interestingly, residues forming the APOBEC3G dimer interface are highly conserved, contrasting with the rapid evolution of two neighboring surface-exposed amino acid patches, one targeted by the Vif protein of primate lentiviruses and the other of yet-undefined function.

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Several factors appear to affect vertical HIV-1 transmission, dependent mainly on characteristics of the mother (extent of immunodeficiency, co-infections, risk behaviour, nutritional status, immune response, genetical make-up), but also of the virus (phenotype, tropism) and, possibly, of the child (genetical make-up). This complex situation is compounded by the fact that the virus may have the whole gestation period, apart from variable periods between membrane rupture and birth and the breast-feeding period, to pass from the mother to the infant. It seems probable that an extensive interplay of all factors occurs, and that some factors may be more important during specific periods and other factors in other periods. Factors predominant in protection against in utero transmission may be less important for peri-natal transmission, and probably quite different from those that predominantly affect transmission by mothers milk. For instance, cytotoxic T lymphocytes will probably be unable to exert any effect during breast-feeding, while neutralizing antibodies will be unable to protect transmission by HIV transmitted through infected cells. Furthermore, some responses may be capable of controlling transmission of determined virus types, while being inadequate for controlling others. As occurence of mixed infections and recombination of HIV-1 types is a known fact, it does not appear possible to prevent vertical HIV-1 transmission by reinforcing just one of the factors, and probably a general strategy including all known factors must be used. Recent reports have brought information on vertical HIV-1 transmission in a variety of research fields, which will have to be considered in conjunction as background for specific studies.

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Most of the Brazilian HIV-1 samples have been characterized based on the structural genes (env, gag and pol) and no data concerning the variability of the accessory genes such as nef have been available so far. Considering the role of the nef on virus biology and the inclusion of this region in some HIV/AIDS vaccine products under testing, the purpose of this study was to document the genetic diversity of the nef gene in third-four HIV-1 Brazilian samples previously subtyped based on the env C2-V3 region. Although only few non-subtype B samples have already been analyzed so far, the cytotoxic Tlymphocyte epitopes encoded in this region were relatively conserved among the subtypes, with some amino acid signatures mainly in the subtype C samples. Considering the increasing of the non-B HIV-1 subtypes worldwide, in special the subtype C, more data should be generated concerning the genetic and antigenic variability of these subtypes, as well as the study of the impact of such polymorphism in HIV/AIDS vaccine design and testing.

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Cardiovascular and chronic kidney disease are epidemic throughout industrialized societies. Diabetes leads to premature cardiovascular disease and is regarded by many as the most common etiological factor for chronic kidney disease. Because most studies of blood-pressure lowering agents in people with diabetes and hypertension have been conducted in individuals who already have some target organ damage, it is unclear whether earlier intervention could prevent or delay the onset of renal or systemic vascular disease. In early disease there is only a low possibility of observing cardiovascular or renal events; thus intervention trials in this population must rely on disease markers such as microalbuminuria. Accordingly, the authors review the evidence to support the use of microalbuminuria as a disease marker in diabetic patients based on its strong association with renal and cardiovascular events, and discuss recent trials that examine the impact of preventing or delaying the onset of microalbuminuria.

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In a prospective field study conducted from July 2000 to June 2001, adult Aedes aegypti and Ae. albopictus mosquitoes were caught from the municipality of Nova Iguaçu, State of Rio de Janeiro, Brazil. Virus isolation in Ae. albopictus clone C6/36 cell line and a semi-nested reverse transcription-polymerase chain reaction detected only dengue virus type 3 in three pools of Ae. aegypti, despite the co-circulation of DEN-1, DEN-2 and DEN-3 serotypes in that area. No viruses were detected in Ae. albopictus mosquitoes. This virological surveillance consists in a sentinel system alerting for dengue outbreaks.

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In 2011 nearly 73,000 adults in Northern Ireland are registered as having diabetes. Many cases of diabetes are preventable and are the result of obesity. With this in mind, on World Diabetes Day, 14 November 2011, the Public Health Agency is encouraging everyone across Northern Ireland to be aware of how Type 2 diabetes can be prevented, the dangers it can cause to your health and what the signs and symptoms of diabetes are to ensure early diagnosis.The links between type 2 diabetes and obesity are firmly established. Without the intervention of a healthy diet and appropriate exercise, obesity may develop into diabetes over a relatively short period of time. According to the International Diabetes Federation (IDF), worldwide 80 per cent of people with Type 2 diabetes are overweight or obese at the time of diagnosis.If you are overweight, or obese the key step to preventing or delaying the onset of Type 2 diabetes is to lose a small amount of weight by making healthy food choices and being physically active 30 minutes a day, 5 days a week.Diabetes, if left untreated can cause serious long term health complications such as heart disease, kidney damage, eye problems, which can affect vision, and foot problems leading to amputation.Dr Brid Farrell, Consultant in Public Health Medicine, PHA, said: "The increase of diabetes occurring in the population can be explained by rising levels of obesity, people living longer and improved detection and diagnosis of diabetes in primary care."Having a family history of Type 2 diabetes increases your chances of developing diabetes. Take the first step today toward lowering your risk for Type 2 diabetes and improving your health and the health of future generations." The symptoms of diabetes can include increased thirst, passing urine more, frequently (bedwetting in children), extreme tiredness, slow healing infections, blurred vision and significant or unexplained weight loss. Symptoms of diabetes can develop quickly over days or weeks, and sometimes with Type 2 diabetes, a person may have no symptoms. Early diagnosis is important. If you think you have diabetes speak to your GP or pharmacist.Dr Farrell continued: "Diabetes is a lifelong condition, but complications can be prevented or delayed by controlling your blood sugar, and treating high blood pressure and high cholesterol. If you have diabetes, a healthy diet and regular exercise is very important."Health Minister Edwin Poots said:"Diabetes is a serious condition, which affects many thousands of people across Northern Ireland. While not all diabetes is preventable, we all have a responsibility to look after our own health. "By making healthier lifestyle choices such as eating a healthy, well-balanced diet and taking regular exercise, we can reduce our risk of developing potentially life threatening conditions such as type 2 diabetes. I would urge everyone to take every possible step to improve their health and avoid developing preventable illnesses

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This booklet has been prepared for those who have recently been diagnosed with Type 2 Diabetes. Type 2 Diabetes is a very common medical condition. While it is a condition that is on the increase, a lot is now known about Type 2 Diabetes and it can be successfully treated and managed so that the person with Diabetes can live a long and healthy life.