23 research outputs found

    Helminths and HIV infection: epidemiological observations on immunological hypotheses

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    Parasitic helminths have co-evolved with the mammalian immune system. Current hypotheses suggest that immunological stimulation in the presence of helminths is balanced by immuno-regulation and by the broad spectrum of mechanisms possessed by helminths for countering the host immune response. The degree to which this balance is perfected, and the mechanisms by which this is achieved, vary between helminth species; we suggest that this is reflected not only in the degree of pathology induced by helminths but also in a variety of relationships with HIV infection and HIV disease. Available epidemiological data regarding interactions between helminths and HIV are largely observational; results are variable and generally inconclusive. Well designed, controlled intervention studies are required to provide definitive information on the species-specific nature of these interactions and on the advantages, disadvantages and optimal timing of de-worming in relation to HIV infection

    Basis for treatment of tuberculosis among HIV-infected patients in Tanzania: the role of chest x-ray and sputum culture

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    BACKGROUND: Active tuberculosis (TB) is common among HIV-infected persons living in tuberculosis endemic countries, and screening for tuberculosis (TB) is recommended routinely. We sought to determine the role of chest x-ray and sputum culture in the decision to treat for presumptive TB using active case finding in a large cohort of HIV-infected patients. METHODS: Ambulatory HIV-positive subjects with CD4 counts ≥ 200/mm3 entering a Phase III TB vaccine study in Tanzania were screened for TB with a physical examination, standard interview, CD4 count, chest x-ray (CXR), blood culture for TB, and three sputum samples for acid fast bacillus (AFB) smear and culture. RESULTS: Among 1176 subjects 136 (12%) were treated for presumptive TB. These patients were more frequently male than those without treatment (34% vs. 25%, respectively; p = 0.049) and had lower median CD4 counts (319/μL vs. 425/μL, respectively; p < .0001). Among the 136 patients treated for TB, 38 (28%) had microbiologic confirmation, including 13 (10%) who had a normal CXR and no symptoms. There were 58 (43%) treated patients in whom the only positive finding was an abnormal CXR. Blood cultures were negative in all patients. CONCLUSION: Many ambulatory HIV-infected patients with CD4 counts ≥ 200/mm3 are treated for presumptive TB. Our data suggest that optimal detection requires comprehensive evaluation, including CXR and sputum culture on both symptomatic and asymptomatic subjects.National Institutes of Health (A1 45407); Fogarty International Center (D43-TW006807

    Advances in structure elucidation of small molecules using mass spectrometry

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    The structural elucidation of small molecules using mass spectrometry plays an important role in modern life sciences and bioanalytical approaches. This review covers different soft and hard ionization techniques and figures of merit for modern mass spectrometers, such as mass resolving power, mass accuracy, isotopic abundance accuracy, accurate mass multiple-stage MS(n) capability, as well as hybrid mass spectrometric and orthogonal chromatographic approaches. The latter part discusses mass spectral data handling strategies, which includes background and noise subtraction, adduct formation and detection, charge state determination, accurate mass measurements, elemental composition determinations, and complex data-dependent setups with ion maps and ion trees. The importance of mass spectral library search algorithms for tandem mass spectra and multiple-stage MS(n) mass spectra as well as mass spectral tree libraries that combine multiple-stage mass spectra are outlined. The successive chapter discusses mass spectral fragmentation pathways, biotransformation reactions and drug metabolism studies, the mass spectral simulation and generation of in silico mass spectra, expert systems for mass spectral interpretation, and the use of computational chemistry to explain gas-phase phenomena. A single chapter discusses data handling for hyphenated approaches including mass spectral deconvolution for clean mass spectra, cheminformatics approaches and structure retention relationships, and retention index predictions for gas and liquid chromatography. The last section reviews the current state of electronic data sharing of mass spectra and discusses the importance of software development for the advancement of structure elucidation of small molecules

    Fatores associados à tuberculose pulmonar em pacientes que procuraram serviços de saúde de referência para tuberculose Factors associated with pulmonary tuberculosis among patients seeking medical attention at referral clinics for tuberculosis

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    OBJETIVO: A identificação de fatores comportamentais e clínicos associados à tuberculose pulmonar pode melhorar a detecção e o tratamento dessa doença, consequentemente reduzindo sua duração e transmissão. Nosso objetivo foi identificar fatores sociodemográficos, clínicos e comportamentais associados à tuberculose pulmonar. MÉTODOS: Estudo transversal realizado entre abril de 2008 e março de 2009 em três unidades de saúde na cidade de Fortaleza (CE). Foram selecionados 233 pacientes maiores de 14 anos que procuraram atendimento médico espontaneamente e que apresentavam tosse por > 2 semanas. Foram coletados dados sociodemográficos, clínicos e comportamentais. Foram realizadas baciloscopia direta para BAAR e cultura de micobactérias, bem como testes tuberculínicos e radiografias de tórax. Os pacientes foram divididos em dois grupos (com e sem tuberculose pulmonar). As variáveis categóricas foram comparadas com o teste do qui-quadrado, seguido de análise de regressão logística quando as variáveis foram consideradas significativas. RESULTADOS: A prevalência de tuberculose pulmonar foi 41,2%. As OR não ajustadas indicaram que as seguintes variáveis foram fatores de risco significativos para tuberculose pulmonar: febre (OR = 2,39; IC95%: 1,34-4,30), anorexia (OR = 3,69; IC95%: 2,03-6,75) e perda de peso (OR = 3,37; IC95%: 1,76-6,62). Na análise multivariada, apenas perda de peso (OR = 3,31; IC95%: 1,78-6,14) associou-se significativamente com tuberculose pulmonar. CONCLUSÕES: Em áreas com elevada prevalência de tuberculose, a perda de peso poderia ser utilizada como um indicador de tuberculose pulmonar em pacientes com tosse crônica por > 2 semanas.<br>OBJECTIVE: The identification of behavioral and clinical factors that are associated with pulmonary tuberculosis might improve the detection and treatment of the disease, thereby reducing its duration and transmission. Our objective was to identify sociodemographic, clinical, and behavioral factors that are associated with the diagnosis of pulmonary tuberculosis. METHODS: This was a cross-sectional study conducted between April of 2008 and March of 2009 at three health care clinics in the city of Fortaleza, Brazil. We selected 233 patients older than 14 years of age who spontaneously sought medical attention and presented with cough for > 2 weeks. Sociodemographic, clinical, and behavioral data were collected. Sputum smear microscopy for AFB and mycobacterial culture were also carried out, as were tuberculin skin tests and chest X-rays. The patients were divided into two groups (with and without pulmonary tuberculosis). The categorical variables were compared by the chi-square test, followed by logistic regression analysis when the variables were considered significant. RESULTS: The prevalence of pulmonary tuberculosis was 41.2%. The unadjusted OR showed that the following variables were statistically significant risk factors for pulmonary tuberculosis: fever (OR = 2.39; 95% CI, 1.34-4.30), anorexia (OR = 3.69; 95% CI, 2.03-6.75), and weight loss (OR = 3.37; 95% CI, 1.76-6.62). In the multivariate analysis, only weight loss (OR = 3.31; 95% CI, 1.78-6.14) was significantly associated with pulmonary tuberculosis. CONCLUSIONS: In areas with a high prevalence of tuberculosis, weight loss could be used as an indicator of pulmonary tuberculosis in patients with chronic cough for > 2 weeks
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