931 resultados para When disease makes history
Resumo:
BACKGROUND: The risk of end stage renal disease (ESRD) is increased among individuals with low income and in low income communities. However, few studies have examined the relation of both individual and community socioeconomic status (SES) with incident ESRD. METHODS: Among 23,314 U.S. adults in the population-based Reasons for Geographic and Racial Differences in Stroke study, we assessed participant differences across geospatially-linked categories of county poverty [outlier poverty, extremely high poverty, very high poverty, high poverty, neither (reference), high affluence and outlier affluence]. Multivariable Cox proportional hazards models were used to examine associations of annual household income and geospatially-linked county poverty measures with incident ESRD, while accounting for death as a competing event using the Fine and Gray method. RESULTS: There were 158 ESRD cases during follow-up. Incident ESRD rates were 178.8 per 100,000 person-years (105 py) in high poverty outlier counties and were 76.3 /105 py in affluent outlier counties, p trend = 0.06. In unadjusted competing risk models, persons residing in high poverty outlier counties had higher incidence of ESRD (which was not statistically significant) when compared to those persons residing in counties with neither high poverty nor affluence [hazard ratio (HR) 1.54, 95% Confidence Interval (CI) 0.75-3.20]. This association was markedly attenuated following adjustment for socio-demographic factors (age, sex, race, education, and income); HR 0.96, 95% CI 0.46-2.00. However, in the same adjusted model, income was independently associated with risk of ESRD [HR 3.75, 95% CI 1.62-8.64, comparing the < $20,000 income group to the > $75,000 group]. There were no statistically significant associations of county measures of poverty with incident ESRD, and no evidence of effect modification. CONCLUSIONS: In contrast to annual family income, geospatially-linked measures of county poverty have little relation with risk of ESRD. Efforts to mitigate socioeconomic disparities in kidney disease may be best appropriated at the individual level.
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Because viral replication depends on the vigour of its host, many viruses have evolved incentives of fitness to pay their keep. When the viral host is a human pathogen, these fitness factors can surface as virulence: creating a Russian doll of pathogenesis where pathogens within pathogens complicate the disease process. Microbial viruses can even be independently immunogenic, as we recently reported for leishmania-virus. Thus, the incidence of this 'hyperpathogenism' is becoming an important clinical consideration and by appreciating the microbial-virus as a backseat driver of human disease, we could exploit its presence as a diagnostic biomarker and molecular target for therapeutic intervention. Here we discuss the prevalence of clinically relevant hyperpathogenism as well as the environmental sanctuaries that breed it.
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Numerous host qualities can modulate parasite fitness, and among these, host nutritive resources and immunity are of prime importance. Indeed, parasite fitness increases with the amount of nutritive resources extracted from the host body and decreases with host immune response. To maximize fitness, parasites have therefore to balance these two host components. Yet, because host nutritive resources and immunity both increase with host body condition, it is unclear whether parasites perform better on hosts in prime, intermediate, or poor condition. We investigated blood meal size and survival of the ectoparasitic louse fly Crataerina melbae in relation to body condition and cutaneous immune response of their Alpine swift (Apus melba) nestling hosts. Louse flies took a smaller blood meal and lived a shorter period of time when feeding on nestlings that were experimentally food deprived or had their cutaneous immune response boosted with methionine. Consistent with these results, louse fly survival was the highest when feeding on nonexperimental nestlings in intermediate body condition. Our findings emphasize that although hosts in poor condition had a reduced immunocompetence, parasites may have avoided them because individuals in poor condition did not provide adequate resources. These findings highlight the fact that giving host immunocompetence primary consideration can result in a biased appraisal of host-parasite interactions.
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All ontogenetic stages of a life cycle are exposed to environmental conditions so that population persistence depends on the performance of both adults and offspring. Most studies analysing the influence of abiotic conditions on species performance have focussed on adults, while studies covering early life-history stages remain rare. We investigated the responses of early stages of two widely introduced ascidians, Styela plicata and Microcosmus squamiger, to different abiotic conditions. Stressors mimicked conditions in the habitats where both species can be found in their distributional ranges and responses were related to the selection potential of their populations by analysing their genetic diversity. Four developmental stages (egg fertilisation, larval development, settlement, metamorphosis) were studied after exposure to high temperature (30°C), low salinities (26 and 22 ) and high copper concentrations (25, 50 and 100 µg/L). Although most stressors effectively led to failure of complete development (fertilisation through metamorphosis), fertilisation and larval development were the most sensitive stages. All the studied stressors affected the development of both species, though responses differed with stage and stressor. S. plicata was overall more resistant to copper, and some stages of M. squamiger to low salinities. No relationship was found between parental genetic composition and responses to stressors. We conclude that successful development can be prevented at several life-history stages, and therefore, it is essential to consider multiple stages when assessing species' abilities to tolerate stress. Moreover, we found that early development of these species cannot be completed under conditions prevailing where adults live. These populations must therefore recruit from elsewhere or reproduce during temporal windows of more benign conditions. Alternatively, novel strategies or behaviours that increase overall reproductive success might be responsible for ensuring population survival.
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Growth arrest-specific gene 6 (Gas6) is expressed in antigen-presenting cells and endothelial cells (ECs) but not in T cells. When wild-type (WT) or Gas6(-/-) mice received allogeneic non-T cell-depleted bone marrow cells, hepatic graft-versus-host disease (GVHD) was alleviated in Gas6(-/-) recipients regardless of donor genotype, but not in WT recipients. T-cell infiltration was more prominent and diffuse in WT than in Gas6(-/-) recipients' liver. When mice received 0.5 x 10(6) allogeneic T cells with T cell-depleted allogeneic bone marrow, clinical signs indicated that GVHD was less severe in Gas6(-/-) than in WT recipients, as shown by a significant improvement of the survival and reduced liver GVHD. These data demonstrate that donor cells were not involved in the protection mechanism. In addition, lack of Gas6 in antigen-presenting cells did not affect WT or Gas6(-/-) T-cell proliferation. We therefore assessed the response of WT or Gas6(-/-) ECs to tumor necrosis factor-alpha. Lymphocyte transmigration was less extensive through Gas6(-/-) than WT ECs and was not accompanied by increases in adhesion molecule levels. Thus, the lack of Gas6 in ECs impaired donor T-cell transmigration into the liver, providing a rationale for considering Gas6 pathway as a potential nonimmunosuppressive target to minimize GVHD in patients receiving allogeneic hematopoietic stem cell transplantation.
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Purpose/Objective(s): Adenosquamous carcinoma (AC) of the head and neck is a distinct entity first described in 1968. Its natural history is more aggressive than squamous cell carcinoma but this is based on very small series reported in the literature. The goal of this study was to assess the clinical profile, outcome, patterns of failure and prognostic factors in patients with AC of the head and neck treated by radiation therapy (RT) with or without chemotherapy (CT).Materials/Methods: Data from 18 patients with Stage I (n = 3), II (n = 1), III (n = 4), or IVa (n = 10) AC, treated between 1989 and 2009, were collected in a retrospective multicenter Rare Cancer Network study. Median age was 60 years (range, 48 - 73 years). Fourteen patients were male and 4 female. Risk factors, including perineural invasion, lymphangitis, vascular invasion, positive margins, were present in 83% of the patients. Tumor sites included oral cavity in 4, oropharynx in 4, hypopharynx in2, larynx in 2, salivary glands in 2, nasal vestibule in 2, nasopharynx in 1, and maxillary sinus in 1 patient. Surgery (S) was performed in all but 5 patients. S alone was performed in only 1 patient, and definitive RT alone in 3 patients. Fourteen patients received combined modality treatment (S+RT in 10, RT+CT in 2, and all of the three modalities in 2 patients). Median RT dose to the primary and to the nodes was 66 Gy (range, 50 - 72 Gy) and 53 Gy (range, 44 - 66 Gy), respectively (1.8 - 2.0 Gy/fr., 5 fr./ week). In 4 patients, the planning treatment volume included the primary tumor site only. Seven patients were treated with 2D RT, 7 with 3D conformal RT, and 2 with intensity-modulated RT.Results: After a median follow-up period of 38 months (range, 9 - 62 months), 8 patients developed distant metastases (lung, bone, mediastinum, and liver), 6 presented nodal recurrences, and only 4 had a local relapse at the primary site (all in-field recurrences). At last follow-up, 6 patients were alive without disease, 1 alive with disease, 9 died from progressive disease, and 2 died from intercurrent disease. The 3-year and median overall survival, disease-free survival (DFS) and locoregional control rates were 52% (95% confidence interval [CI]: 28 - 76%) and 39 months, 36% (95% CI: 13 - 49%) and 12 months, and 54% (95% CI: 26 - 82%) and 40 months, respectively. In multivariate analysis (Cox model), DFS was negatively influenced by the presence of extracapsular extension (p = 0.02) and advanced stage (IV versus I-III, p = 0.003).Conclusions: Overall prognosis of locoregionally advanced AC remains poor, and distant metastases and nodal relapse occur in almost half of the cases. However, local control is relatively good, and early stage AC patients had prolonged DFS when treated with combined modality treatment.
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There is little information concerning the long term outcome of patients with gastro-oesophageal reflux disease (GORD). Thus 109 patients with reflux symptoms (33 with erosive oesophagitis) with a diagnosis of GORD after clinical evaluation and oesophageal testing were studied. All patients were treated with a stepwise approach: (a) lifestyle changes were suggested aimed at reducing reflux and antacids and the prokinetic agent domperidone were prescribed; (b) H2 blockers were added after two months when symptoms persisted; (c) anti-reflux surgery was indicated when there was no response to (b). Treatment was adjusted to maintain clinical remission during follow up. Long term treatment need was defined as minor when conservative measures sufficed for proper control, and as major if daily H2 blockers or surgery were required. The results showed that one third of the patients each had initial therapeutic need (a), (b), and (c). Of 103 patients available for follow up at three years and 89 at six years, respective therapeutic needs were minor in 52% and 55% and major in 48% and 45%. Eighty per cent of patients in (a), 67% in (b), and 17% in (c) required only conservative measures at six years. A decreasing lower oesophageal sphincter pressure (p < 0.001), radiological reflux (p = 0.028), and erosive oesophagitis (p = 0.031), but not initial clinical scores, were independent predictors of major therapeutic need as shown by multivariate analysis. The long term outcome of GORD is better than previously perceived.
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BACKGROUND: Because of the known relationship between exposure to combination antiretroviral therapy and cardiovascular disease (CVD), it has become increasingly important to intervene against risk of CVD in human immunodeficiency virus (HIV)-infected patients. We evaluated changes in risk factors for CVD and the use of lipid-lowering therapy in HIV-infected individuals and assessed the impact of any changes on the incidence of myocardial infarction. METHODS: The Data Collection on Adverse Events of Anti-HIV Drugs Study is a collaboration of 11 cohorts of HIV-infected patients that included follow-up for 33,389 HIV-infected patients from December 1999 through February 2006. RESULTS: The proportion of patients at high risk of CVD increased from 35.3% during 1999-2000 to 41.3% during 2005-2006. Of 28,985 patients, 2801 (9.7%) initiated lipid-lowering therapy; initiation of lipid-lowering therapy was more common for those with abnormal lipid values and those with traditional risk factors for CVD (male sex, older age, higher body mass index [calculated as the weight in kilograms divided by the square of the height in meters], family and personal history of CVD, and diabetes mellitus). After controlling for these, use of lipid-lowering drugs became relatively less common over time. The incidence of myocardial infarction (0.32 cases per 100 person-years [PY]; 95% confidence interval [CI], 0.29-0.35 cases per 100 PY) appeared to remain stable. However, after controlling for changes in risk factors for CVD, the rate decreased over time (relative rate in 2003 [compared with 1999-2000], 0.73 cases per 100 PY [95% CI, 0.50-1.05 cases per 100 PY]; in 2004, 0.64 cases per 100 PY [95% CI, 0.44-0.94 cases per 100 PY]; in 2005-2006, 0.36 cases per 100 PY [95% CI, 0.24-0.56 cases per 100 PY]). Further adjustment for lipid levels attenuated the relative rates towards unity (relative rate in 2003 [compared with 1999-2000], 1.06 cases per 100 PY [95% CI, 0.63-1.77 cases per 100 PY]; in 2004, 1.02 cases per 100 PY [95% CI, 0.61-1.71 cases per 100 PY]; in 2005-2006, 0.63 cases per 100 PY [95% CI, 0.36-1.09 cases per 100 PY]). CONCLUSIONS: Although the CVD risk profile among patients in the Data Collection on Adverse Events of Anti-HIV Drugs Study has decreased since 1999, rates have remained relatively stable, possibly as a result of a more aggressive approach towards managing the risk of CVD.
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After a relatively normal childhood, people suffering from cystic fibrosis reach a stage where they are progressively confronted with increasingly crippling functional limitations. Some of them nonetheless regularly undertake physical and/or sporting activity. It is then interesting to examine the process of commitment to a practice that is based on the idea of progress and often exceptional performance by the body but which, for these people, makes the decline of their physical capacities particularly salient. The qualitative survey combines participant observation with 35 semi-directive interviews with sportsmen and women with cystic fibrosis. Their commitment to sport, constructed by/with the family is initially first aimed maintaining a form of control over their identity but progressively becomes a means of controlling the illness trajectory. Lung transplant, when possible, relaunches the practice in relation to its initial interests.
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Background and aims: Because of the changing epidemiology of Inflammatory Bowel Diseases 0131)), we set out to characterize the population-based prevalence of Crohn's Disease (CD) and Ulcerative Colitis (UC) in a defined population of Switzerland. Methods: Adult IBD patients were identified by a cross-matched review of histological, hospital and gastroenterologist files throughout a geographical defined population (Canton of Vaud). Demographic factors statistically significantly associated with prevalence were evaluated using a stepwise Poisson regression analysis. Results were compared to IBD prevalence rates in other population-based studies and time trends were performed, based on a systematic literature review. Results: Age and sex-adjusted prevalence rates were 205.7 IBD (100.7 CD and 105.0 UC) cases per 105 inhabitants. Among 1016 IBD patients (519 CD and 497 UC), females outnumbered mates in CD (p < 0.001), but mates were more represented in elderly UC patients (p = 0.008). Thus, being a mate was statistically associated with UC (Relative Risk (RR) 1.25; p = 0.013), whereas being a female was associated with CD (RR 1.27; p = 0.007). Living in an urban zone was associated with both CD and UC (RR 1.49; p < 0.001, 1.63; p < 0.001, respectively). From 1960 to 2005, increases in UC and CD prevalences of 2.4% (95%CI, 2.1%-2.8%; p < 0.001) and 3.6% (95%CI, 3.1%-4.1%; p < 0.001) per annum were found in industrialised countries.
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There is evidence that obesity-related disorders are increased among people with depression. Variation in the FTO (fat mass and obesity associated) gene has been shown to contribute to common forms of human obesity. This study aimed to investigate the genetic influence of polymorphisms in FTO in relation to body mass index (BMI) in two independent samples of major depressive disorder (MDD) cases and controls. We analysed 88 polymorphisms in the FTO gene in a clinically ascertained sample of 2442 MDD cases and 809 controls (Radiant Study). In all, 8 of the top 10 single-nucleotide polymorphisms (SNPs) showing the strongest associations with BMI were followed-up in a population-based cohort (PsyCoLaus Study) consisting of 1292 depression cases and 1690 controls. Linear regression analyses of the FTO variants and BMI yielded 10 SNPs significantly associated with increased BMI in the depressive group but not the control group in the Radiant sample. The same pattern was found in the PsyCoLaus sample. We found a significant interaction between genotype and affected status in relation to BMI for seven SNPs in Radiant (P<0.0057), with PsyCoLaus giving supportive evidence for five SNPs (P-values between 0.03 and 0.06), which increased in significance when the data were combined in a meta-analysis. This is the first study investigating FTO and BMI within the context of MDD, and the results indicate that having a history of depression moderates the effect of FTO on BMI. This finding suggests that FTO is involved in the mechanism underlying the association between mood disorders and obesity.
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When remission of Crohn's disease is achieved, the next goal is to maintain long-term remission. Aminosalicylates may be recommended for maintenance remission, even though the results are less consistent than those observed in ulcerative colitis. The benefit is mainly observed in the post-surgical setting and in patients with ileitis, and with a prolonged disease duration. Corticosteroids are not effective in maintaining remission and should not be used for this indication. Azathioprine and 6-mercaptopurine are effective in maintaining remission. Maintenance benefits remain significant for patients who continued with the therapy for up to 5 years. Methotrexate has also been found to be effective in maintaining remission in Crohn's disease in patients who have responded acutely to methotrexate. Cyclosporine has not been found to be an effective maintenance agent. Mycophenolate mofetil could be considered a therapy in patients who are either allergic to azathioprine or in whom azathioprine failed to induce remission. The use of infliximab may change the future approach to maintenance therapy for Crohn's disease. Patients who responded clinically to infliximab have maintained their clinical response when receiving repeat infusions at 8-week intervals. In patients refractory to other therapies, infliximab may be effective in maintaining remission.
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With the current limited availability of organs for transplantation, it is important to consider marginal donor candidates, including survivors of potentially curable malignancies such as lymphoma. The absence of refractory/recurrent residual disease at the time of brain death can be difficult to establish. Therefore, it is critical to have objective data to decide whether to proceed or not with organ procurement and transplantation. We report a unique situation in which (18)F-fluorodeoxyglucose positron emission tomography (PET) was used to rule out Hodgkin's lymphoma recurrence in a 33-year-old, heart-beating, brain-dead, potential donor with a past history of Hodgkin's disease and a persistent mediastinal mass. PET showed no significant uptake in the mass, allowing organ donation and transplantation to occur. We present a new means of evaluating potential brain-dead donors with a past history of some lymphoma, whereby PET may help transplant physicians by optimizing donation safety while rationalizing the inclusion of marginal donors.
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In certain cases of sudden death, forensic experts may discover during an investigation or autopsy that family members of the deceased are also at risk of harm-from genetic disease, for instance. But do they have a duty to warn them? Looking at similar duties of physicians and researchers to warn third parties of risk suggests they do.
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One of the challenges that faces the winter maintainer is how much chemical to apply to the road under given conditions. Insufficient chemical can lead to the road surface becoming slick, and the road thus becoming unsafe. In all likelihood, additional applications will have to be made, requiring additional effort and use of resources. However, too much chemical can also be bad. While an excess of chemical will ensure (in most circumstances) that a safe road condition is achieved, it may also result in a substantial waste of chemical (with associated costs for this waste) and in ancillary damage to the road itself and to the surrounding environment. Ideally, one should apply what might be termed the “goldilocks” amount of chemical to the road: Not too much, and not too little, but just right. Of course the reality of winter maintenance makes achieving the “goldilocks” application rate somewhat of a fairy tale. In the midst of a severe storm, when conditions are poor and getting worse, the last thing on a plow operator’s mind is a minute adjustment in the amount of chemical being applied to the road. However, there may be considerable benefit and substantial savings to be achieved if chemical applications can be optimized to some degree, so that wastage is minimized without compromising safety. The goal of this study was to begin to develop such information through a series of laboratory studies in which the force needed to scrape ice from concrete blocks was measured, under a variety of chemical application conditions.