36 resultados para Anemia falciforme

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


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Background: Anemia and dementia are common diseases among the elderly, but conflicting data are available regarding an association between these two conditions. We analyzed data from the Sao Paulo Ageing & Health Study to address the relationship between anemia and dementia. Methods: This cross-sectional observational study included participants aged 65 years and older from a deprived area of the borough of Butantan, Sao Paulo, Brazil. Data about demographics, education, income, and cognitive and daily life function were collected, as well as blood samples. Anemia and dementia were defined according to WHO and DSM-IV criteria, respectively. Results: Of the 2267 subjects meeting the inclusion criteria, 2072 agreed to participate in the study; of whom 1948 had a valid total blood count and were included in the analysis. Anemia was diagnosed in 203 (10.2%) participants and dementia in 99 (5.1%). The frequency of anemia was higher in patients with dementia according to univariate analysis (odds ratio (OR) = 2.00, 95% confidence interval (CI) = 1.17-3.41, p = 0.01), but this association was not present after adjusting for age (OR = 1.33, 95% CI = 0.76-2.33, p = 0.32). Further multivariate adjustment did not change the results. Conclusion: Although anemia and dementia are frequent disorders in older people, we found their relationship to be mediated exclusively by aging in this low-income population from Sao Paulo.

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Objective: To estimate the prevalence of anemia and analyze the factors associated with anemia in elderly residents of long-term care institutions. Methods: This cross-sectional study was performed in male and female elderly volunteers selected in a two-stage random sampling from long-term care institutions in the city of Maringa, Brazil (2008). A diagnosis of anemia was based on the plasma hemoglobin concentration. The independent variables analyzed were gender, age, time of residence at an institution, body mass index, and serum iron and albumin concentrations. The association between anemia and the variables was assessed using the Poisson regression with robust variance in unadjusted and adjusted analyses, considering a complex sample and a significance level of 5%. Results: The sample included 124 adults older than 60 y residing in long-term care institutions (53.0% female). The prevalence of anemia was 29% and was not significantly associated with gender, serum iron concentration, time of residence at an institution, or body mass index. Conversely, hypoalbuminemia was considered a risk factor for anemia. Conclusion: There is a high prevalence of anemia in the institutionalized elderly and hypoalbuminemia is a factor associated with this outcome. Interventions are necessary to promote improvements in the health and welfare of this population. (C) 2012 Published by Elsevier Inc.

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Background: Although iron deficiency is considered to be the main cause of anemia in children worldwide, other contributors to childhood anemia remain little studied in developing countries. We estimated the relative contributions of different factors to anemia in a population-based, cross-sectional survey. Methodology: We obtained venous blood samples from 1111 children aged 6 months to 10 years living in the frontier town of Acrelandia, northwest Brazil, to estimate the prevalence of anemia and iron deficiency by measuring hemoglobin, erythrocyte indices, ferritin, soluble transferrin receptor, and C-reactive protein concentrations. Children were simultaneously screened for vitamin A, vitamin B-12, and folate deficiencies; intestinal parasite infections; glucose-6-phosphate dehydrogenase deficiency; and sickle cell trait carriage. Multiple Poisson regression and adjusted prevalence ratios (aPR) were used to describe associations between anemia and the independent variables. Principal Findings: The prevalence of anemia, iron deficiency, and iron-deficiency anemia were 13.6%, 45.4%, and 10.3%, respectively. Children whose families were in the highest income quartile, compared with the lowest, had a lower risk of anemia (aPR, 0.60; 95% CI, 0.37-0.98). Child age (<24 months, 2.90; 2.01-4.20) and maternal parity (>2 pregnancies, 2.01; 1.40-2.87) were positively associated with anemia. Other associated correlates were iron deficiency (2.1; 1.4-3.0), vitamin B-12 (1.4; 1.0-2.2), and folate (2.0; 1.3-3.1) deficiencies, and C-reactive protein concentrations (>5 mg/L, 1.5; 1.1-2.2). Conclusions: Addressing morbidities and multiple nutritional deficiencies in children and mothers and improving the purchasing power of poorer families are potentially important interventions to reduce the burden of anemia.

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Sickle cell anemia (SCA) is associated to increased cardiac output, normal heart rate (HR), abnormal QT dispersion and lower diastolic blood pressure (DBP). The mechanisms are still unknown. The objective of this study was to test the hypothesis that there is cardiovascular autonomic dysfunction (CAD) in SCA. The secondary objectives were to distinguish the roles of chronic anemia and hemoglobinopathy and to evaluate the predominance of the sympathetic or parasympathetic systems in the pathogenesis of CAD. Sixteen subjects with SCA, 13 with sickle cell trait (SCT), 13 with iron deficiency anemia (IDA), and 13 healthy volunteers (HV) were evaluated. All subjects were submitted to 24 h-electrocardiogram (24 h-ECG), plasma norepinephrine (NE) measurement before and after isometric exercise (IE), and also Valsalva maneuver (VM), diving maneuver (DV), and tilt test (TT). Baroreflex sensitivity (BRS) was also evaluated. The minimum, average and maximum HR as well as the percentage of bradycardia and tachycardia at 24-h ECG were similar in all groups. NE at baseline and after IE did not differ between groups. The SCA group showed less bradycardia at phase IV of VM, less bradycardia during DV, and also less tachycardia and lower DBP during TT. BRS for bradycardia and tachycardia reflex was decreased in the SCA and SCT groups. In conclusion, 1) there is CAD in SCA, and it is characterized by the reduction of BRS and the limitation of HR modulation mediated by the parasympathetic system; 2) cardiovascular sympathetic activity is preserved in SCA; and 3) hemoglobinopathy is the preponderant ethiopathogenic factor. (C) 2011 Elsevier B.V. All rights reserved.

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Abstract Background Myelodysplastic syndromes (MDS) are a group of clonal hematological disorders characterized by ineffective hematopoiesis with morphological evidence of marrow cell dysplasia resulting in peripheral blood cytopenia. Microarray technology has permitted a refined high-throughput mapping of the transcriptional activity in the human genome. Non-coding RNAs (ncRNAs) transcribed from intronic regions of genes are involved in a number of processes related to post-transcriptional control of gene expression, and in the regulation of exon-skipping and intron retention. Characterization of ncRNAs in progenitor cells and stromal cells of MDS patients could be strategic for understanding gene expression regulation in this disease. Methods In this study, gene expression profiles of CD34+ cells of 4 patients with MDS of refractory anemia with ringed sideroblasts (RARS) subgroup and stromal cells of 3 patients with MDS-RARS were compared with healthy individuals using 44 k combined intron-exon oligoarrays, which included probes for exons of protein-coding genes, and for non-coding RNAs transcribed from intronic regions in either the sense or antisense strands. Real-time RT-PCR was performed to confirm the expression levels of selected transcripts. Results In CD34+ cells of MDS-RARS patients, 216 genes were significantly differentially expressed (q-value ≤ 0.01) in comparison to healthy individuals, of which 65 (30%) were non-coding transcripts. In stromal cells of MDS-RARS, 12 genes were significantly differentially expressed (q-value ≤ 0.05) in comparison to healthy individuals, of which 3 (25%) were non-coding transcripts. Conclusions These results demonstrated, for the first time, the differential ncRNA expression profile between MDS-RARS and healthy individuals, in CD34+ cells and stromal cells, suggesting that ncRNAs may play an important role during the development of myelodysplastic syndromes.

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OBJECTIVE: The oxidative stress in 20 sickle cell anemia patients taking hydroxyurea and 13 sickle cell anemia patients who did not take hydroxyurea was compared with a control group of 96 individuals without any hemoglobinopathy. METHODS: Oxidative stress was assessed by thiobarbituric acid reactive species production, the Trolox-equivalent antioxidant capacity and plasma glutathione levels. RESULTS: Thiobarbituric acid reactive species values were higher in patients without specific medication, followed by patients taking hydroxyurea and the Control Group (p < 0.0001). The antioxidant capacity was higher in patients taking hydroxyurea and lower in the Control Group (p = 0.0002 for Trolox-equivalent antioxidant capacity and p < 0.0292 for plasma glutathione). Thiobarbituric acid reactive species levels were correlated with higher hemoglobin S levels (r = 0.55; p = 0.0040) and lower hemoglobin F concentrations(r = -0.52; p = 0.0067). On the other hand, plasma glutathione levels were negatively correlated with hemoglobin S levels (r = -0.49; p = 0.0111) and positively associated with hemoglobin F values (r = 0.56; p = 0.0031). CONCLUSION: Sickle cell anemia patients have high oxidative stress and, conversely, increased antioxidant activity. The increase in hemoglobin F levels provided by hydroxyurea and its antioxidant action may explain the reduction in lipid peroxidation and increased antioxidant defenses in these individuals.

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Dapsone use is frequently associated to hematological side effects such as methemoglobinemia and hemolytic anemia, which are related to N-hydroxylation mediated by the P450 enzyme system. The aim of the present study was to evaluate the influence of L-arginine supplementation, a precursor for the synthesis of nitric oxide, as single or multiple dose regimens on dapsone-induced methemoglobinemia. Male Wistar rats were treated with L-arginine at 5, 15, 30, 60 and 180 mg/kg doses (p.o., gavage) in single or multiple dose regimens 2 hours prior to dapsone administration (40 mg/kg, i.p.). The effect of the nitric oxide synthase inhibitor L-NAME was investigated by treatment with multiple doses of 30 mg/kg (p.o., gavage) 2 hours before dapsone administration. Blood samples were collected 2 hours after dapsone administration. Erythrocytic methemoglobin levels were assayed by spectrophotometry. The results showed that multiple dose supplementations with 5 and 15 mg/kg L-arginine reduced dapsone-induced methemoglobin levels. This effect is mediated by nitric oxide formation, since the reduction in methemoglobin levels by L-arginine is blocked by simultaneous administration with L-NAME, a nitric oxide synthase inhibitor.

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An important step when designing a vaccine is identifying the antigens that function as targets of naturally acquired antibodies. We investigated specific antibody responses against two Plasmodium vivax vaccine candidates, PvMSP-1(19) and PvMSP-3 alpha(359-798). Moreover, we assessed the relationship between these antibodies and morbidity parameters. PvMSP-1(19) was the most immunogenic antigen and the frequency of responders to this protein tended to increase in P. vivax patients with higher parasitemia. For both antigens, IgG antibody responses tended to be lower in patients who had experienced their first bout of malaria. Furthermore, anemic patients presented higher IgG antibody responses to PvMSP-3 alpha(359-798). Since the humoral response involves a number of antibodies acting simultaneously on different targets, we performed a Principal Component Analysis (PCA). Anemic patients had, on average, higher first principal component scores (IgG1/IgG2/IgG3/IgG4 anti-MSP3 alpha), which were negatively correlated with hemoglobin levels. Since antibodies against PfMSP-3 have been strongly associated with clinical protection, we cannot exclude the possibility of a dual role of PvMSP-3 specific antibodies in both immunity and pathogenesis of vivax malaria. Our results confirm the high immunogenicity of the conserved C terminus of PvMSP-1 and points to the considerable immunogenicity of polymorphic PvMSP-3 alpha(359-798) during natural infection. (C) 2012 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

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Mutations in the coding region of telomerase complex genes can result in accelerated telomere attrition and human disease. Manifestations of telomere disease include the bone marrow failure syndromes dyskeratosis congenita and aplastic anemia, acute myeloid leukemia, liver cirrhosis, and pulmonary fibrosis. Here, we describe a mutation in the CCAAT box (GCAAT) of the TERC gene promoter in a family in which multiple members had typical features of telomeropathy. The genetic alteration in this critical regulatory sequence resulted in reduced reporter gene activity and absent binding of transcription factor NF-Y, likely responsible for reduced TERC levels, decreased telomerase activity, and short telomeres. This is the first description of a pathogenic mutation in the highly con-served CCAAT box and the first instance of a mutation in the promoter region of TERC producing a telomeropathy. We propose that current mutation-screening strategies should include gene promoter regions for the diagnosis of telomere diseases. This clinical trial was registered at www.clinicaltrials.gov as #NCT00071045. (Blood. 2012;119(13):3060-3063)

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Human cells are constantly exposed to DNA damage. Without repair, damage can result in genetic instability and eventually cancer. The strong association between the lack of DNA damage repair, mutations and cancer is dramatically demonstrated by a number of cancer-prone human syndromes, such as xeroderma pigmentosum (XP), ataxia-telangiectasia (AT) and Fanconi anemia (FA). This review focuses on the historical discoveries related with these three diseases and describes their impact on the understanding of DNA repair mechanisms and the causes of human cancer. As deficiencies in DNA repair are also often related with progeria symptoms, unrepaired damage and aging are somehow related. Several other pathologies associated with DNA repair defects, genetic instability and increased cancer risk are also discussed. In fact, studies with cells from these many syndromes have helped in understanding important levels of protection against cancer and aging, although little help has actually been conferred to the patients in terms of therapy. Finally, the recent advances in combined basic and translational research on DNA repair and chemotherapy are presented.

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The purpose of this study is to estimate the survival probability of patients following their first admission for the treatment of AIDS to an infectious disease reference hospital in Belo Horizonte, Brazil, during 2005. Study subjects were monitored during a 12-month period to identify factors associated with survival probability. Late diagnosis was recorded among many of the 250 study subjects: almost half (44.8%) were diagnosed less than 30 days prior to or during their hospitalization. A high mortality rate was also detected: 39.6% of the subjects died during the 12 months of monitoring. The cumulative survival probability of the cohort group was estimated at 68.0% after 3 months and at 61.2% after 12 months. However, certain patient subgroups analyzed had even lower cumulative survival probabilities after 12 months of monitoring: if diagnosed during hospitalization, it was estimated at only 48.0% and those with no record of antiretroviral treatment had a 48.5% cumulative survival probability. Patients with severe anemia had the lowest survival probability, similar among the two lymphocyte count groups (<1000 mm(3) and >= 1000 mm(3)), the former with a 45.5% survival probability and the latter with a 46.7% one. The proportional death risk was 2.5-fold higher for men residing in other area than the capital city of the State of Minas Gerais and greater metropolitan region when compared with women residing there. The findings of this study highlight the importance of early diagnosis for predicting patient survival and reinforce the necessity off acilitating HIV diagnosis.

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Background/purpose: Gallstones and cholelithiasis are being increasingly diagnosed in children owing to the widespread use of ultrasonography. The treatment of choice is cholecystectomy, and routine intraoperative cholangiography is recommended to explore the common bile duct. The objectives of this study were to describe our experience with the management of gallstone disease in childhood over the last 18 years and to propose an algorithm to guide the approach to cholelithiasis in children based on clinical and ultrasonographic findings. Methods: The data for this study were obtained by reviewing the records of all patients with gallstone disease treated between January 1994 and October 2011. The patients were divided into the following 5 groups based on their symptoms: group 1, asymptomatic; group 2, nonbiliary obstructive symptoms; group 3, acute cholecystitis symptoms; group 4, a history of biliary obstructive symptoms that were completely resolved by the time of surgery; and group 5, ongoing biliary obstructive symptoms. Patients were treated according to an algorithm based on their clinical, ultrasonographic, and endoscopic retrograde cholangiopancreatography (ERCP) findings. Results: A total of 223 patients were diagnosed with cholelithiasis, and comorbidities were present in 177 patients (79.3%). The most common comorbidities were hemolytic disorders in 139 patients (62.3%) and previous bariatric surgery in 16 (7.1%). Although symptoms were present in 134 patients (60.0%), cholecystectomy was performed for all patients with cholelithiasis, even if they were asymptomatic; the surgery was laparoscopic in 204 patients and open in 19. Fifty-six patients (25.1%) presented with complications as the first sign of cholelithiasis (eg, pancreatitis, choledocolithiasis, or acute calculous cholecystitis). Intraoperative cholangiography was indicated in 15 children, and it was positive in only 1 (0.4%) for whom ERCP was necessary to extract the stone after a laparoscopic cholecystectomy (LC). Preoperative ERCP was performed in 11 patients to extract the stones, and a hepaticojejunostomy was indicated in 2 patients. There were no injuries to the hepatic artery or common bile duct in our series. Conclusions: Based on our experience, we can propose an algorithm to guide the approach to cholelithiasis in the pediatric population. The final conclusion is that LC results in limited postoperative complications in children with gallstones. When a diagnosis of choledocolithiasis or dilation of the choledocus is made, ERCP is necessary if obstructive symptoms persist either before or after an LC. Intraoperative cholangiography and laparoscopic common bile duct exploration are not mandatory. Published by Elsevier Inc.

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Hb S-Sao Paulo (SP) [HBB:c.20A > T p.Glu6Val: c.196A > G p.Lys65Glu] is a new double-mutant hemoglobin that was found in heterozygosis in an 18-month-old Brazilian male with moderate anemia. It behaves like Hb S in acid electrophoresis, isoelectric focusing and solubility testing but shows different behavior in alkaline electrophoresis, cation-exchange HPLC and RP-HPLC. The variant is slightly unstable, showed reduced oxygen affinity and also appeared to form polymers more stable than the Hb S. Molecular dynamics simulation suggests that the polymerization is favored by interfacial electrostatic interactions. This provides a plausible explanation for some of the reported experimental observations. (C) 2012 Elsevier Inc. All rights reserved.

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Lipid nanoemulsions (LDE) may be used as carriers of paclitaxel (PTX) and etoposide (ETP) to decrease toxicity and increase the therapeutic action of those drugs. The current study investigates the combined chemotherapy with PTX and ETP associated with LDE. Four groups of 10-20 B16F10 melanoma-bearing mice were treated with LDE-PTX and LDE-ETP in combination (LDE-PTX + ETP), commercial PTX and ETP in combination (PTX + ETP), single LDE-PTX, and single LDE-ETP. PTX and ETX doses were 9 mu mol/kg administered in three intraperitoneal injections on three alternate days. In two control groups mice were treated with saline solution or LDE alone. Tumor growth, metastasis presence, cell-cycle distribution, blood cell counts and histological data were analyzed. Toxicity of all treatments was evaluated in mice without tumors. Tumor growth inhibition was similarly strong in all treatment groups. However, there was a greater reduction in the number of animals bearing metastases in the LDE-PTX + ETP group (30 %) in comparison to the PTX + ETP group (82 %, p < 0.05). Reduction of cellular density, blood vessels and increase of collagen fibers in tumor tissues were observed in the LDE-PTX + ETP group but not in the PTX + ETP group, and in both groups reduced melanoma-related anemia and thrombocytosis were observed. Flow cytometric analysis suggested that LDE-PTX + ETP exhibited greater selectivity to neoplastic cells than PTX-ETP, showing arrest (65 %) in the G(2)/M phase of the cell cycle (p < 0.001). Toxicity manifested by weight loss and myelosuppression was markedly milder in the LDE-PTX + ETP than in the PTX + ETP group. LDE-PTX + ETP combined drug-targeting therapy showed markedly superior anti-cancer properties and reduced toxicity compared to PTX + ETP.