924 resultados para Kahn, Edgar


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Background The objectives were to estimate the prevalence of hepatitis A among children and adolescents from the Northeast and Midwest regions and the Federal District of Brazil and to identify individual-, household- and area-levels factors associated with hepatitis A infection. Methods This population-based survey was conducted in 20042005 and covered individuals aged between 5 and 19 years. A stratified multistage cluster sampling technique with probability proportional to size was used to select 1937 individuals aged between 5 and 19 years living in the Federal capital and in the State capitals of 12 states in the study regions. The sample was stratified according to age (59 and 10- to 19-years-old) and capital within each region. Individual- and household-level data were collected by interview at the home of the individual. Variables related to the area were retrieved from census tract data. The outcome was total antibodies to hepatitis A virus detected using commercial EIA. The age distribution of the susceptible population was estimated using a simple catalytic model. The associations between HAV infection and independent variables were assessed using the odds ratio and corrected for the random design effect and sampling weight. Multilevel analysis was performed by GLLAMM using Stata 9.2. Results The prevalence of hepatitis A infection in the 59 and 1019 age-group was 41.5 and 57.4, respectively for the Northeast, 32.3 and 56.0, respectively for the Midwest and 33.8 and 65.1 for the Federal District. A trend for the prevalence of HAV infection to increase according to age was detected in all sites. By the age of 5, 31.5 of the children had already been infected with HAV in the Northeast region compared with 20.0 in the other sites. By the age of 19 years, seropositivity was 70 in all areas. The curves of susceptible populations differed from one area to another. Multilevel modeling showed that variables relating to different levels of education were associated with HAV infection in all sites. Conclusion The study sites were classified as areas with intermediate endemicity area for hepatitis A infection. Differences in age trends of infection were detected among settings. This multilevel model allowed for quantification of contextual predictors of hepatitis A infection in urban areas.

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Background Recent studies indicate an increased frequency of mutations in the gene encoding glucocerebrosidase (GBA), a deficiency of which causes Gaucher`s disease, among patients with Parkinson`s disease. We aimed to ascertain the frequency of GBA mutations in an ethnically diverse group of patients with Parkinson`s disease. Methods Sixteen centers participated in our international, collaborative study: five from the Americas, six from Europe, two from Israel, and three from Asia. Each center genotyped a standard DNA panel to permit comparison of the genotyping results across centers. Genotypes and phenotypic data from a total of 5691 patients with Parkinson`s disease (780 Ashkenazi Jews) and 4898 controls (387 Ashkenazi Jews) were analyzed, with multivariate logistic-regression models and the Mantel-Haenszel procedure used to estimate odds ratios across centers. Results All 16 centers could detect two GBA mutations, L444P and N370S. Among Ashkenazi Jewish subjects, either mutation was found in 15% of patients and 3% of controls, and among non-Ashkenazi Jewish subjects, either mutation was found in 3% of patients and less than 1% of controls. GBA was fully sequenced for 1883 non-Ashkenazi Jewish patients, and mutations were identified in 7%, showing that limited mutation screening can miss half the mutant alleles. The odds ratio for any GBA mutation in patients versus controls was 5.43 across centers. As compared with patients who did not carry a GBA mutation, those with a GBA mutation presented earlier with the disease, were more likely to have affected relatives, and were more likely to have atypical clinical manifestations. Conclusions Data collected from 16 centers demonstrate that there is a strong association between GBA mutations and Parkinson`s disease.

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We have shown that rats chronically treated with Arginine (Arg), although normoglycemic, exhibit hyperinsulinemia and decreased blood glucose disappearance rate after an insulin challenge. Attempting to investigate the processes underlying these alterations, male Wistar rats were treated with Arg (35 mg/d), in drinking water, for 4 wk. Rats were then acutely stimulated with insulin, and the soleus and extensorum digitalis longus muscles, white adipose tissue (WAT), and liver were excised for total and/or phosphorylated insulin receptor (IR), IR substrate 1/2, Akt, Janus kinase 2, signal transducer and activator of transcription (STAT) 1/3/5, and p85 alpha/55 alpha determination. Muscles and WAT were also used for plasma membrane (PM) and microsome evaluation of glucose transporter (GLUT) 4 content. Pituitary GH mRNA, GH, and liver IGF-I mRNA expression were estimated. It was shown that Arg treatment: 1) did not affect phosphotyrosine-IR, whereas it decreased phosphotyrosine-IR substrate 1/2 and phosphoserine-Akt content in all tissues studied, indicating that insulin signaling is impaired at post-receptor level; 2) decreased PM GLUT4 content in both muscles and WAT; 3) increased the pituitary GH mRNA, GH, and liver IGF-I mRNA expression, the levels of phosphotyrosine-STAT5 in both muscles, phosphotyrosine-Janus kinase 2 in extensorum digitalis longus, phosphotyrosine-STAT3 in liver, and WAT as well as total p85 alpha in soleus, indicating that GH signaling is enhanced in these tissues; and 4) increased p55 alpha total content in muscles, WAT, and liver. The present findings provide the molecular mechanisms by which insulin resistance and, by extension, reduced GLUT4 content in PM of muscles and WAT take place after chronic administration of Arg, and further suggest a putative role for GH in its genesis, considering its diabetogenic effect. (Endocrinology 150: 2080-2086, 2009)

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Unfolded protein response (UPR)-mediated pancreatic beta-cell death has been described as a common mechanism by which palmitate (PA) and pro-inflammatory cytokines contribute to the development of diabetes. There are evidences that interleukin 6 (IL6) has a protective action against beta-cell death induced by proinflammatory cytokines; the effects of IL6 on PA-induced apoptosis have not been investigated yet. In the present study, we have demonstrated that PA selectively disrupts IL6-induced RAC-alpha serine/threonine-protein kinase (AKT) activation without interfering with signal transducer and activator of transcription 3 phosphorylation in RINm5F cells. The inability of IL6 to activate AKT in the presence of PA correlated with an inefficient protection against PA-induced apoptosis. In contrast to PA, IL6 efficiently reduced apoptosis induced by pro-inflammatory cytokines. In addition, we have demonstrated that IL6 is unable to overcome PA-stimulated UPR, as assessed by activating transcription factor 4 (ATF4) andC/EBP homologous protein (CHOP) expression, X-box binding protein-1 gene mRNA splicing, and pancreatic eukaryotic initiation factor-2 alpha kinase phosphorylation, whereas no significant induction of UPR by pro-inflammatory cytokines was detected. This unconditional stimulation of UPR and apoptosis by PA was accompanied by the stimulation of CHOP and tribble3 (TRIB3) expression, irrespective of the presence of IL6. These findings suggest that IL6 is unable to protect pancreatic beta-cells from PA-induced apoptosis because it does not repress UPR activation. In this way, CHOP and ATF4 might mediate PA-induced TRIB3 expression and, by extension, the suppression of IL6 activation of pro-survival kinase AKT. Journal of Endocrinology (2010) 206, 183-193

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Focal and segmental glomerulosclerosis (FSGS) is one of the most important causes of end-stage renal failure. The bradykinin B1 receptor has been associated with tissue inflammation and renal fibrosis. To test for a role of the bradykinin B1 receptor in podocyte injury, we pharmacologically modulated its activity at different time points in an adriamycin-induced mouse model of FSGS. Estimated albuminuria and urinary protein to creatinine ratios correlated with podocytopathy. Adriamycin injection led to loss of body weight, proteinuria, and upregulation of B1 receptor mRNA. Early treatment with a B1 antagonist reduced albuminuria and glomerulosclerosis, and inhibited the adriamycin-induced downregulation of podocin, nephrin, and alpha-actinin-4 expression. Moreover, delayed treatment with antagonist also induced podocyte protection. Conversely, a B1 agonist aggravated renal dysfunction and even further suppressed the levels of podocyte-related molecules. Thus, we propose that kinin has a crucial role in the pathogenesis of FSGS operating through bradykinin B1 receptor signaling. Kidney International (2011) 79, 1217-1227; doi:10.1038/ki.2011.14; published online 16 March 2011

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Background. Periodontal diseases (PDs) are infectious diseases in which periodontopathogens trigger chronic inflammatory and immune responses that lead to tissue destruction. Recently, viruses have been implicated in the pathogenesis of PDs. Individuals infected with human T lymphotropic virus 1 (HTLV-1) present with abnormal oral health and a marked increased prevalence of periodontal disease. Methods. In this study, we investigated the patterns of periodontopathogen infection and local inflammatory immune markers in HTLV-1-seropositive individuals with chronic periodontitis (CP/HTLV-1 group) compared with HTLV-1 -seronegative individuals with chronic periodontitis (CP group) and periodontally healthy, HTLV-1 -seronegative individuals (control group). Results. Patients in the CP/HTLV-1 group had significantly higher values of bleeding on probing, mean probing depth, and attachment loss than patients in the CP group. The expression of tumor necrosis factor a and interleukin (IL) 4 was found to be similar in the CP and CP/HTLV-1 groups, whereas IL-12 and IL-17 levels trended toward a higher expression in the CP/HTLV-1 group. A significant increase was seen in the levels of IL-1 beta and interferon gamma in the CP/HTLV-1 group compared with the CP group, whereas expression of the regulatory T cell marker FOXp3 and IL-10 was significantly decreased in the lesions from the CP/HTLV-1 group. Interestingly, similar frequency and/or load of periodontopathogens (Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Aggregatibacter actinomycetemcomitans) and frequency of viruses (herpes simplex virus 1, human cytomegalovirus, and Epstein-Barr virus) characteristically associated with PDs were found in the CP/HTLV and CP groups. Conclusions. HTLV-1 may play a critical role in the pathogenesis of periodontal disease through the deregulation of the local cytokine network, resulting in an exacerbated response against a standard periodontopathogen infection.

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The residual stress distribution that arises in the glass matrix during cooling of a partially crystallized 17.2Na(2)O-32.1CaO-48.1SiO(2)-2.5P(2)O(5) (mol%) bioactive glass-ceramic was measured using the Vickers indentation method proposed by Zeng and Rowcliffe (ZR). The magnitude of the determined residual stress at the crystal/glass boundary was 1/4-1/3 of the values measured using X-ray diffraction (within the crystals) and calculated using Selsing`s model. A correction for the crack geometry factor, assuming a semi-elliptical shape, is proposed and then good agreement between experimental and theoretical values is found. Thus, if the actual crack geometry is taken into account, the indentation technique of ZR can be successfully used. In addition, a numerical model for the calculation of residual stresses that takes into account the hemispherical shape of the crystalline precipitates at a free surface was developed. The result is that near the sample surface, the radial component of the residual stress is increased by 70% in comparison with the residual stress calculated by Selsing`s model.

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Let L be an RA loop, that is, a loop whose loop ring over any coefficient ring R is an alternative, but not associative, ring. Let l bar right arrow l(theta) denote an involution on L and extend it linearly to the loop ring RL. An element alpha is an element of RL is symmetric if alpha(theta) = alpha and skew-symmetric if alpha(theta) = -alpha. In this paper, we show that there exists an involution making the symmetric elements of RL commute if and only if the characteristic of R is 2 or theta is the canonical involution on L, and an involution making the skew-symmetric elements of RL commute if and only if the characteristic of R is 2 or 4.

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We investigate polynomial identities on an alternative loop algebra and group identities on its (Moufang) unit loop. An alternative loop ring always satisfies a polynomial identity, whereas whether or not a unit loop satisfies a group identity depends on factors such as characteristic and centrality of certain kinds of idempotents.

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We determine the structure of the semisimple group algebra of certain groups over the rationals and over those finite fields where the Wedderburn decompositions have the least number of simple components We apply our work to obtain similar information about the loop algebras of mdecomposable RA loops and to produce negative answers to the isomorphism problem over various fields (C) 2010 Elsevier Inc All rights reserved

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There is a need of scientific evidence of claimed nutraceutical effects, but also there is a social movement towards the use of natural products and among them algae are seen as rich resources. Within this scenario, the development of methodology for rapid and reliable assessment of markers of efficiency and security of these extracts is necessary. The rat treated with streptozotocin has been proposed as the most appropriate model of systemic oxidative stress for studying antioxidant therapies. Cystoseira is a brown alga containing fucoxanthin and other carothenes whose pressure-assisted extracts were assayed to discover a possible beneficial effect on complications related to diabetes evolution in an acute but short-term model. Urine was selected as the sample and CE-TOF-MS as the analytical technique to obtain the fingerprints in a non-target metabolomic approach. Multivariate data analysis revealed a good clustering of the groups and permitted the putative assignment of compounds statistically significant in the classification. Interestingly a group of compounds associated to lysine glycation and cleavage from proteins was found to be increased in diabetic animals receiving vehicle as compared to control animals receiving vehicle (N6, N6, N6-trimethyl-L-lysine, N-methylnicotinamide, galactosylhydroxylysine, L-carnitine, N6-acetyl-N6-hydroxylysine, fructose-lysine, pipecolic acid, urocanic acid, amino-isobutanoate, formylisoglutamine. Fructoselysine significantly decreased after the treatment changing from a 24% increase to a 19% decrease. CE-MS fingerprinting of urine has provided a group of compounds different to those detected with other techniques and therefore proves the necessity of a cross-platform analysis to obtain a broad view of biological samples.

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In this work, a CE equipment, online hyphenated to an IT MS analyzer by a linear sheath liquid interface promoting ESI, was used to develop a method for quantitative determination of amino acids. Under appropriate conditions (BGE composition, 0.8% HCOOH, 20% CH(3)OH; sheath liquid composition, 0.8% HCOOH, 60% methanol; V(ESI), +4.50 W), analytical curves of all amino acids from 3 to 80 mg/L were recorded presenting acceptable linearity (r > 0.99). LODs in the range of 16-172 mu mol/L were obtained. BSA, a model protein, was submitted to different hydrolysis procedures (classical acid and basic, and catalyzed by the H(+) form of a cation exchanger resin) and its amino acid profiles determined. In general, the resin-mediated hydrolysis yields were overall similar or better than those obtained by classical acid or basic hydrolysis. The resulting experimental-to-theoretical BSA concentration ratios served as correction factors for the quantitation of amino acids in Brazil nut resin generated hydrolysates.

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The essential oil from seeds of Licaria puchury-major was isolated by hydrodistillation. The chemical composition of the oil was analyzed by GC and GUMS. Sixteen compounds were identified, representing 91.4% of the total oil. The major components were safrole (58.4%), dodecanoic acid (13.7%) and alpha-terpineol (8.4%). Oxygenated monoterpenoids were the main group of compounds.

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Fourier Transformed Infrared Spectroscopy, Thermogravimetric Analysis, and X-ray Diffractometry have been used to investigate the rigid, semi rigid, and soft polyurethane (PU) forms, which were developed by the Group of Analytic Chemistry and Technology of Polymers - USF - Sao Carlos. The -NCO/-OH ratios were 0.6, 0.5, and 0.3% for rigid, semi rigid, and soft PUs, respectively, showing that different ratios cause differences in thermal behaviors and crystalline structures of the synthesized PU resins. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 263-268, 2010

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The study of Aloysia gratissima essential oil from leaves was obtained by hydrodistillation using a Clevenger type apparatus. The essential oil composition was analyzed by GC and GC/MS. The major compounds were identified representing 94.7% of the oil. The most abundant compounds were isopinocamphone (cis-3-pinanone) (25.4%), limonene (15.1%), and guaiol (12.7%).