908 resultados para vitamin B group
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BACKGROUND: Vitamin D insufficiency has been associated with the occurrence of various types of cancer, but causal relationships remain elusive. We therefore aimed to determine the relationship between genetic determinants of vitamin D serum levels and the risk of developing hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). METHODOLOGY/PRINCIPAL FINDINGS: Associations between CYP2R1, GC, and DHCR7 genotypes that are determinants of reduced 25-hydroxyvitamin D (25[OH]D3) serum levels and the risk of HCV-related HCC development were investigated for 1279 chronic hepatitis C patients with HCC and 4325 without HCC, respectively. The well-known associations between CYP2R1 (rs1993116, rs10741657), GC (rs2282679), and DHCR7 (rs7944926, rs12785878) genotypes and 25(OH)D3 serum levels were also apparent in patients with chronic hepatitis C. The same genotypes of these single nucleotide polymorphisms (SNPs) that are associated with reduced 25(OH)D3 serum levels were found to be associated with HCV-related HCC (P = 0.07 [OR = 1.13, 95% CI = 0.99-1.28] for CYP2R1, P = 0.007 [OR = 1.56, 95% CI = 1.12-2.15] for GC, P = 0.003 [OR = 1.42, 95% CI = 1.13-1.78] for DHCR7; ORs for risk genotypes). In contrast, no association between these genetic variations and liver fibrosis progression rate (P>0.2 for each SNP) or outcome of standard therapy with pegylated interferon-α and ribavirin (P>0.2 for each SNP) was observed, suggesting a specific influence of the genetic determinants of 25(OH)D3 serum levels on hepatocarcinogenesis. CONCLUSIONS/SIGNIFICANCE: Our data suggest a relatively weak but functionally relevant role for vitamin D in the prevention of HCV-related hepatocarcinogenesis.
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BACKGROUND: Chronic hepatitis C infection is a major cause of end-stage liver disease. Therapy outcome is influenced by 25-OH vitamin D deficiency. To further address this observation, our study investigates the impact of the vitamin D receptor (NR1I1) haplotype and combined effects of plasma vitamin D levels in a well-described cohort of hepatitis C patients. METHODS: A total of 155 chronic hepatitis C patients were recruited from the Swiss Hepatitis C Cohort Study for NR1I1 genotyping and plasma 25-OH vitamin D level measurement. NR1I1 genotype data and combined effects of plasma 25-OH vitamin D level were analysed regarding therapy response (sustained virological response). RESULTS: A strong association was observed between therapy non-response and the NR1I1 CCA (bAt) haplotype consisting of rs1544410 (BsmI) C, rs7975232 (ApaI) C and rs731236 (TaqI) A alleles. Of the HCV patients carrying the CCA haplotype, 50.3% were non-responders (odds ratio [OR] 1.69, 95% CI 1.07, 2.67; P=0.028). A similar association was observed for the combinational CCCCAA genotype (OR 2.94, 95% CI 1.36, 6.37; P=0.007). The combinational CCCCAA genotype was confirmed as an independent risk factor for non-response in multivariate analysis (OR 2.50, 95% CI 1.07, 5.87; P=0.034). Analysing combined effects, a significant impact of low 25-OH vitamin D levels on sustained virological response were only seen in patients with the unfavourable NR1I1 CCA (bAt) haplotype (OR for non-SVR 3.55; 95% CI 1.005, 12.57; P=0.049). CONCLUSIONS: NR1I1 vitamin D receptor polymorphisms influence response to pegylated-interferon/ribavirin-based therapy in chronic hepatitis C and exert an additive genetic predisposition to previously described low 25-OH vitamin D serum levels.
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BACKGROUND: Decreased vitamin D levels have been described in various forms of chronic liver disease and associated with advanced fibrosis. Whether this association is a cause or consequence of advanced fibrosis remains unclear to date. AIMS: To analyse combined effects of 25-OH vitamin D plasma levels and vitamin D receptor gene (VDR; NR1I1) polymorphisms on fibrosis progression rate in HCV patients. METHODS: 251 HCV patients underwent VDR genotyping (bat-haplotype: BsmI rs1544410 C, ApaI rs7975232 A and TaqI rs731236 A). Plasma 25-OH vitamin D levels were quantified in a subgroup of 97 patients without advanced fibrosis. The VDR haplotype and genotypes as well as plasma 25-OH vitamin D levels were associated with fibrosis progression. RESULTS: The bAt[CCA]-haplotype was significantly associated with fibrosis progression >0.101 U/year (P = 0.007; OR = 2.02) and with cirrhosis (P = 0.022; OR = 1.84). Forty-five percent of bAt[CCA]-haplotype patients were rapid fibrosers, 21.1% were cirrhotic. Likewise, ApaI rs7975232 CC genotype was significantly associated with fibrosis progression and cirrhosis. Lower plasma 25-OH vitamin D levels were significantly associated with fibrosis progression >0.101 U/year in F0-2 patients (P = 0.013). Combined analysis of both variables revealed a highly significant additive effect on fibrosis progression with 45.5% rapid fibrosers for bAt[CCA]-haplotype and 25-OH vitamin D < 20 μg/L compared with only 9.1% for the most favourable combination (P = 0.006). In multivariate analysis, the bAt-haplotype was an independent risk factor for fibrosis progression (P = 0.001; OR = 2.83). CONCLUSION: Low 25-OH vitamin D plasma levels and the unfavourable VDR bAt[CCA]-haplotype are associated with rapid fibrosis progression in chronic HCV patients. In combination, both variables exert significant additive effects on fibrosis progression.
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Carcinoembryonic antigen (CEA) was purified from primary tumour or from hepatic metastases obtained from ten cases of carcinoma of the colon. In nine cases the blood group antigens A, B, Lea or Leb were detected in CEA preparations by the binding of 125I-labelled CEA by blood group antibodies. The extent of binding appeared to preclude simple contamination of CEA preparations by blood group glycoprotein. In all cases the blood group antigens detected were consistent with the patients' known blood groups. Blood group I and i activities were not detected. It is concluded that the determinants of A, B and Lewis antigens and of CEA share the same glycoprotein carrier molecules.
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The incidence and outcome of group B streptococcal (GBS) sepsis were assessed prospectively between September 2011 and February 2015 in all tertiary care pediatric hospitals of Switzerland. We describe a low incidence of GBS early-onset sepsis (0.12/1000 livebirths) and a predominance of GBS late-onset sepsis (0.36/1000 livebirths), a pattern that has not been reported in other countries.
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Porcine group A rotavirus (PoRVA) is a major cause of neonatal diarrhea in suckling and recently weaned piglets worldwide. The involvement of non-group A rotavirus in cases of neonatal diarrhea in piglets are sporadic. In Brazil there are no reports of the porcine rotavirus group C (PoRVC) as etiologic agent of the diarrhea outbreaks in piglets. The aim of this study was to describe the identification of rotavirus group C in single and in mixed infection with rotavirus groups A and B in three neonatal diarrhea outbreaks in suckling (<21-day-old) piglets, with 70% to 80% and 20% to 25% of morbidity and lethality rates, respectively, in three pig herds located in the state of Santa Catarina, Brazil. The diagnosis of PoRV in the diarrheic fecal samples was performed using polyacrylamide gel electrophoresis (PAGE) to identify the presence of porcine rotavirus groups A, B (PoRVB), and C, and by RT-PCR (PoRVA and PoRVC) and semi-nested (SN)-PCR (PoRVB) to partially amplify the VP4 (VP8*)-VP7, NSP2, and VP6 genes of PoRVA, PoRVB, and PoRVC, respectively. One RT-PCR (PoRVA and PoRVC) and SN-PCR (PoRVB) product of each group of rotavirus of each diarrhea outbreak was submitted to nucleotide (nt) sequence analysis. Based on the PAGE technique, 4 (25%) and 1 (6.25%) of the 16 diarrheic fecal samples evaluated in the first outbreak presented PoRVA and PoRVC electropherotype, respectively, and 11 (68.75%) were negative. In the second outbreak, 3 (42.85%) of the 7 fecal samples evaluated presented PoRVA electropherotype, and in 3 (42.85%) and in 1 (14.3%) fecal samples were detected inconclusive and negative results, respectively. Three (30%) of the 10 fecal samples of the third outbreak presented PoRVC electropherotype; 5 (50%) and 2 (20%) samples showed negative and inconclusive results, respectively. Based on the RT-PCR and SN-PCR assays in the first neonatal diarrhea outbreak, PoRVC was detected in 13 (81.2%) of the 16 diarrheic fecal samples evaluated. PoRVC single infection was identified in 4 (25%) of these samples and mixed infections with PoRVA and PoRVB in 9 (56.2%) fecal samples. All of the seven diarrheic fecal samples evaluated from the second neonatal diarrhea outbreak were positive for PoRVC, whereas its mixed infection with other PoRV groups was detected in 4 (57.2%) samples. In the third outbreak, PoRVC in single infection was detected in all of the 10 diarrheic fecal samples analyzed. In the nt sequence analysis, the PoRVA strains of the first and second outbreaks demonstrated higher nt identity with G4P[6] and G9P[23] genotypes, respectively. The PoRVB strains (first and second outbreaks) and the PoRVC strains (first, second, and third outbreaks) showed higher nt identity and clustered in the phylogenetic tree with PoRVB and PoRVC strains that belong to the N4 and I1 genotypes, respectively. This is the first description in Brazil of the involvement of PoRVC in the etiology of diarrhea outbreaks in suckling piglets. The results of this study demonstrated that PoRVC, in both single and mixed infections, is an important enteropathogen involved in neonatal diarrhea outbreaks in piglets and that the use of more sensitive diagnostic techniques allows the identification of mixed infections involving two or even three groups of PoRV, which may be more common than previously reported.
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The objective of this multicenter prospective study was to determine the clinical efficacy and toxicity of a polychemotherapeutic third generation regimen, VACOP-B, with or without radiotherapy as front-line therapy in aggressive localized non-Hodgkin's lymphoma. Ninety-three adult patients (47 males and 46 females, median age 45 years) with aggressive localized non-Hodgkin's lymphoma, 43 in stage I and 50 in stage II (non-bulky), were included in the study. Stage I patients received VACOP-B for 6 weeks plus involved field radiotherapy and stage II patients received 12 weeks VACOP-B plus involved field radiotherapy on residual masses. Eighty-six (92.5%) achieved complete remission and 4 (4.3%) partial remission. Three patients (3.2%) were primarily resistant. Ten-year probability of survival, progression-free survival and disease-free survival were 87.3, 79.9 and 83.9%, respectively. Eighty-four patients are surviving at a median observation time of 57 months (range: 6-126). Statistical analysis showed no difference between stages I and II in terms of response, ten-year probability of survival, progression-free survival or disease-free survival. Side effects and toxicity were negligible and were similar in the two patient groups. The results of this prospective study suggest that 6 weeks of VACOP-B treatment plus radiotherapy may be the therapy of choice in stage I aggressive non-Hodgkin's lymphoma. Twelve weeks of VACOP-B treatment with or without radiotherapy was shown to be effective and feasible for stage II. These observations need to be confirmed by a phase III study comparing first and third generation protocols in stage I-II aggressive non-Hodgkin's lymphoma.
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This thesis can be broken down into two sections. Section one is a study . of the ionization mechanisms and the ion source optimization for Fast Atom Bombardment (FAB) ionization. For this study, several specially designed probe tips were created and tested under various experimental conditions. The aIm of this section is to understand the operating characteristics of a FAB IOn source better. The second section involves the study of several Vitamin B6 Schiff Base complexes using both positive and negative ion FAB MS. This section is an exploration of the usefulness of FAB MS as a structure probe for the metalcoordination complexes of Vitamin B6.
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Vitamin D metabolites are important in the regulation of bone and calcium homeostasis, but also have a more ubiquitous role in the regulation of cell differentiation and immune function. Severely low circulating 25-dihydroxyvitamin D [25(OH)D] concentrations have been associated with the onset of active tuberculosis (TB) in immigrant populations, although the association with latent TB infection (LTBI) has not received much attention. A previous study identified the prevalence of LTBI among a sample of Mexican migrant workers enrolled in Canada's Seasonal Agricultural Workers Program (SA WP) in the Niagara Region of Ontario. The aim of the present study was to determine the vitamin D status of the same sample, and identify if a relationship existed with LTBI. Studies of vitamin D deficiency and active TB are most commonly carried out among immigrant populations to non-endemic regions, in which reactivation of LTBI has occurred. Currently, there is limited knowledge of the association between vitamin D deficiency and LTBI. Entry into Canada ensured that these individuals did not have active TB, and L TBI status was established previously by an interferon-gamma release assay (IGRA) (QuantiFERON-TB Gold In-Tube®, Cellestis Ltd., Australia). Awareness of vitamin D status may enable individuals at risk of deficiency to improve their nutritional health, and those with LTBI to be aware of this risk factor for disease. Prevalence of vitamin D insufficiency among the Mexican migrant workers was determined from serum samples collected in the summer of 2007 as part of the cross sectional LTBI study. Samples were measured for concentrations of the main circulating vitamin D metabolite, 25(OH)D, with a widely used 1251 250HD RIA (DiaSorin Inc.®, Stillwater, MN), and were categorized as deficient «37.5 nmoI/L), insufficient (>37.5 nmollL, < 80 nmol/L) or sufficient (2::80 nmoI/L). Fisher's exact tests and t tests were used to determine if vitamin D status (sufficiency or insufficiency) or 25(OH)D concentrations significantly differed by sex or age categories. Predictors of vitamin D insufficiency and 25(OH)D concentrations were taken from questionnaires carried out during the previous study, and analyzed in the present study using multiple regression prediction models. Fisher's exact test and t test was used to determine if vitamin D status or 25(OH)D concentration differed by LTBI status. Strength of the relationship between interferongamma (IFN-y) concentration (released by peripheral T cells in response to TB antigens) and 25(OH)D concentration was analyzed using a Spearman correlation. Out of 87 participants included in the study (78% male; mean age 38 years), 14 were identified as LTBI positive but none had any signs or symptoms of TB reactivation. Only 30% of the participants were vitamin D sufficient, whereas 68% were insufficient and 2% were deficient. Significant independent predictors of lower 25(OH)D concentrations were sex, number of years enrolled in the SA WP and length of stay in Canada. No significant differences were found between 25(OH)D concentrations and LTBI status. There was a significant moderate correlation between IFN-y and 25(OH)D concentrations ofLTBI-positive individuals. The majority of participants presented with Vitamin D insufficiency but none were severely deficient, indicating that 25(OH)D concentrations do not decrease dramatically in populations who temporarily reside in Canada but go back to their countries of origin during the Canadian winter. This study did not find a statistical relationship between low levels of vitamin D and LTBI which suggests that in the presence of overall good health, lower than ideal levels of 2S(OH)D, may still be exerting a protective immunological effect against LTBI reactivation. The challenge remains to determine a critical 2S(OH)D concentration at which reactivation is more likely to occur.
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Le Streptocoque de groupe B (GBS) est un important agent d’infection invasive pouvant mener à la mort et demeure la cause principale de septicémie néonatale à ce jour. Neuf sérotypes ont été officiellement décrits basés sur la composition de la capsule polysaccharidique (CPS). Parmi ces sérotypes, le type III est considéré le plus virulent et fréquemment associé aux maladies invasives graves, telle que la méningite. Malgré que plusieurs recherches aient été effectuées au niveau des interactions entre GBS type III et les cellules du système immunitaire innées, aucune information n’est disponible sur la régulation de la réponse immunitaire adaptative dirigée contre ce dernier. Notamment, le rôle de cellules T CD4+ dans l’immuno-pathogenèse de l’infection causée par GBS n’a jamais été étudié. Dans cet étude, trois différents modèles murins d’infection ont été développé pour évaluer l’activation et la modulation des cellules T CD4+ répondantes au GBS de type III : ex vivo, in vivo, et in vitro. Les résultats d’infections ex vivo démontrent que les splénocytes totaux répondent à l’infection en produisant des cytokines de type-1 pro-inflammatoires. Une forte production d’IL-10 accompagne cette cascade inflammatoire, probablement dans l’effort de l’hôte de maintenir l’homéostasie. Les résultats démontrent aussi que les cellules T sont activement recrutées par les cellules répondantes du système inné en produisant des facteurs chimiotactiques, tels que CXCL9, CXCL10, et CCL3. Plus spécifiquement, les résultats obtenus à partir des cellules isolées T CD4+ provenant des infections ex vivo ou in vivo démontrent que ces cellules participent à la production d’IFN-γ et de TNF-α ainsi que d’IL-2, suggérant un profil d’activation Th1. Les cellules isolées T CD4+ n’étaient pas des contributeurs majeurs d’IL-10. Ceci indique que cette cytokine immuno-régulatrice est principalement produite par les cellules de l’immunité innée de la rate de souris infectées. Le profil Th1 des cellules T CD4+ a été confirmé en utilisant un modèle in vitro. Nos résultats démontrent aussi que la CPS de GBS a une role immuno-modulateur dans le développement de la réponse Th1. En résumé, cette étude adresse pour la première fois, la contribution des cellules T CD4+ dans la production d’IFN-γ lors d’une infection à GBS et donc, dans le développement d’une réponse de type Th1. Ces résultats renforcent d’avantage le rôle central de cette cytokine pour un control efficace des infections causées par ce pathogène.
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In the present study, the initial phase was directed to confirm the effects of curcumin and vitamin D3 in preventing or delaying diabetes onset by studying the blood glucose and insulin levels in the pre-treated and diabetic groups. Behavioural studies were conducted to evaluate the cognitive and motor function in experimental rats. The major focus of the study was to understand the cellular and neuronal mechanisms that ensure the prophylactic capability of curcumin and vitamin D3. To elucidate the mechanisms involved in conferring the antidiabetogenesis effect, we examined the DNA and protein profiles using radioactive incorporation studies for DNA synthesis, DNA methylation and protein synthesis. Furthermore the gene expression studies of Akt-1, Pax, Pdx-1, Neuro D1, insulin like growth factor-1 and NF-κB were done to monitor pancreatic beta cell proliferation and differentiation. The antioxidant and antiapoptotic actions of curcumin and vitamin D3 were examined by studying the expression of antioxidant enzymes - SOD and GPx, and apoptotic mediators like Bax, caspase 3, caspase 8 and TNF-α. In order to understand the signalling pathways involved in curcumin and vitamin D3 action, the second messengers, cAMP, cGMP and IP3 were studied along with the expression of vitamin D receptor in the pancreas. The neuronal regulation of pancreatic beta cell maintenance, proliferation and insulin release was studied by assessing the adrenergic and muscarinic receptor functional regulation in the pancreas, brain stem, hippocampus and hypothalamus. The receptor number and binding affinity of total muscarinic, muscarinic M1, muscarinic M3, total adrenergic, α adrenergic and β adrenergic receptor subtypes were studied in pancreas, brain stem and hippocampus of experimental rats. The mRNA expression of muscarinic and adrenergic receptor subtypes were determined using Real Time PCR. Immunohistochemistry studies using confocal microscope were carried out to confirm receptor density and gene expression results. Cell signalling alterations in the pancreas and brain regions associated with diabetogenesis and antidiabetogenesis were assessed by examining the gene expression profiles of vitamin D receptor, CREB, phospholipase C, insulin receptor and GLUT. This study will establish the anti-diabetogenesis activity of curcumin and vitamin D3 pre-treatment and will attempt to understand the cellular, molecular and neuronal control mechanism in the onset of diabetes.Administration of MLD-STZ to curcumin and vitamin D3 pre-treated rats induced only an incidental prediabetic condition. Curcumin and vitamin D3 pretreated groups injected with MLD-STZ exhibited improved circulating insulin levels and behavioural responses when compared to MLD-STZ induced diabetic group. Activation of beta cell compensatory response induces an increase in pancreatic insulin output and beta cell mass expansion in the pre-treated group. Cell signalling proteins that regulate pancreatic beta cell survival, insulin release, proliferation and differentiation showed a significant increase in curcumin and vitamin D3 pre-treated rats. Marked decline in α2 adrenergic receptor function in pancreas helps to relent sympathetic inhibition of insulin release. Neuronal stimulation of hyperglycemia induced beta cell compensatory response is mediated by escalated signalling through β adrenergic, muscarinic M1 and M3 receptors. Pre-treatment mediated functional regulation of adrenergic and cholinergic receptors, key cell signalling proteins and second messengers improves pancreatic glucose sensing, insulin gene expression, insulin secretion, cell survival and beta cell mass expansion in pancreas. Curcumin and vitamin D3 pre-treatment induced modulation of adrenergic and cholinergic signalling in brain stem, hippocampus and hypothalamus promotes insulin secretion, beta cell compensatory response, insulin sensitivity and energy balance to resist diabetogenesis. Pre-treatment improved second messenger levels and the gene expression of intracellular signalling molecules in brain stem, hippocampus and hypothalamus, to retain a functional neuronal response to hyperglycemia. Curcumin and vitamin D3 protect pancreas and brain regions from oxidative stress by their indigenous antioxidant properties and by their ability to stimulate cellular free radical defence system. The present study demonstrates the role of adrenergic and muscarinic receptor subtypes functional regulation in curcumin and vitamin D3 mediated anti-diabetogenesis. This will have immense clinical significance in developing effective strategies to delay or prevent the onset of diabetes.
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Background: Exposure to solar ultraviolet-B (UV-B) radiation is a major source of vitamin D3. Chemistry climate models project decreases in ground-level solar erythemal UV over the current century. It is unclear what impact this will have on vitamin D status at the population level. The purpose of this study was to measure the association between ground-level solar UV-B and serum concentrations of 25-hydroxyvitamin D (25(OH)D) using a secondary analysis of the 2007 to 2009 Canadian Health Measures Survey (CHMS). Methods: Blood samples collected from individuals aged 12 to 79 years sampled across Canada were analyzed for 25(OH)D (n=4,398). Solar UV-B irradiance was calculated for the 15 CHMS collection sites using the Tropospheric Ultraviolet and Visible Radiation Model. Multivariable linear regression was used to evaluate the association between 25(OH)D and solar UV-B adjusted for other predictors and to explore effect modification. Results: Cumulative solar UV-B irradiance averaged over 91 days (91-day UV-B) prior to blood draw correlated significantly with 25(OH)D. Independent of other predictors, a 1 kJ/m 2 increase in 91-day UV-B was associated with a significant 0.5 nmol/L (95% CI 0.3-0.8) increase in mean 25(OH)D (P =0.0001). The relationship was stronger among younger individuals and those spending more time outdoors. Based on current projections of decreases in ground-level solar UV-B, we predict less than a 1 nmol/L decrease in mean 25(OH)D for the population. Conclusions: In Canada, cumulative exposure to ambient solar UV-B has a small but significant association with 25(OH)D concentrations. Public health messages to improve vitamin D status should target safe sun exposure with sunscreen use, and also enhanced dietary and supplemental intake and maintenance of a healthy body weight.