189 resultados para Autoimmune Hemolytic Anemia


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Iron deficiency is a common nutritional disorder, affecting about 30% of the world population. Deficits in iron functional compartments have suppressive effects on the immune system. Environmental problems, age, and other nutrient deficiencies are some of the situations which make human studies difficult and warrant the use of animal models. This study aimed to investigate alterations in the immune system by inducing iron deficiency and promoting recuperation in a mouse model. Hemoglobin concentration, hematocrit, liver iron store, and flow cytometry analyses of cell-surface transferrin receptor (CD71) on peripheral blood and spleen CD4+ and CD8+ T lymphocyte were performed in the control (C) and the iron-deficient (ID) groups of animals at the beginning and end of the experiment. Hematological indices of C and ID mice were not different but the iron stores of ID mice were significantly reduced. Although T cell subsets were not altered, the percentage of T cells expressing CD71 was significantly increased by ID. The results suggest that iron deficiency induced by our experimental model would mimic the early events in the onset of anemia, where thymus atrophy is not enough to influence subset composition of T cells, which can still respond to iron deficiency by upregulating the expression of transferrin receptor.

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Enterococci can be used in the food industry as starter or probiotic cultures. However, enterococci are also implicated in severe multi-resistant nosocomial infections. In this study, the prevalence of enterococci in selected Brazilian foodstuffs (raw and pasteurized milk, meat products, cheeses and vegetables) was evaluated. Phenotypic and PCR protocols were used for species identification. Tests for production of gelatinase, haemolysin, bacteriocin and bile salt hydrolysis were done with all enterococci isolates, whereas molecular determination of virulence markers (genes esp, gel, ace, as, efaA, hyl and cylA) and antibiotic resistance was checked only for Enterococcus faecium and Enterococcus faecalis isolates. The antibiotic-resistant isolates were assayed for biofilm formation and adhesion to mammalian cells. From the 120 food samples analyzed, 52.5% were positive for enterococci, meat and cheese being the most contaminated. E. faecium was the predominant species, followed by E. faecalis, E. casseliflavus and Enterococcus gallinarum. Phenotypic tests indicated that 67.7% of isolates hydrolyzed bile salts, 15.2% produced bacteriocin, 12.0% were beta-hemolytic and 18.2% produced gelatinase. Antibiotic resistance (gentamicin, tetracycline and erythromycin) and genes encoding for virulence traits were more frequent in E. faecalis than in E. faecium. Three E. faecium isolates were resistant to vancomycin. Among antibiotic-resistant isolates, 72.4% of E. faecalis were able to form biofilm and 13.8% to adhere to Caco-2 cells. Antibiotic-resistant E. faecalis and E. faecium isolates were grouped by RAPD-PCR and a scattered distribution was noted, indicating that resistance was not related to a particular clone. The spread of virulence/resistance traits in isolates of the two species and different RAPD-types suggest the pathogenic potential of both species. By contrast, the recovery of bacteriocinogenic E. faecium isolates with no virulence traits suggests their potential for biotechnological applications. In conclusion, our results showed that enterococci from Brazilian foods present important dualist aspects for food safety. (C) 2008 Elsevier Ltd. All rights reserved.

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Sickle cell disease (SCD) is an inherited disorder caused by a single nucleotide substitution in the P-globin gene. The clinical heterogeneity observed in SCD patients has been attributed to environmental and genetic factors. The patients are subjected to increased oxidative stress, particularly during vaso-occlusive crises and acute chest pain. Another possible cause of oxidative stress in SCD is the high concentration of iron in the patients` plasma. The increase in oxidative stress could be a relevant risk factor for mutagenesis and carcinogenesis. Studies on the frequency of basal chromosomal aberrations in cultured lymphocytes from SCD patients have not been reported so far. In order to contribute to the understanding of the role of the different biomarkers and their relationship with the extremely variable clinical manifestation of SCD, we investigated the frequency of chromosome damage in peripheral lymphocytes from sickle cells patients and healthy controls. We found an increased frequency of chromosome damage and percentage of aberrant metaphases in these patients when compared with control subjects, even at basal values (p < 0.05). In the cytogenetic sensitivity assay, the results showed that these patients presented a marked decrease in the mitotic index values compared with healthy controls. Cisplatin-induced chromosomal damage in lymphocytes from these patients was significantly higher than the frequency measured in healthy controls. The results obtained in the present study showed that more investigations are needed in order to elucidate the susceptibility to genomic instability of SCD patients.

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Galectin-1 (Gal-1) and galectin-3 (Gal-3) exhibit profound but unique immunomodulatory activities in animals but their molecular mechanisms are incompletely understood. Early studies suggested that Gal-1 inhibits leukocyte function by inducing apoptotic cell death and removal, but recent studies show that some galectins induce exposure of the common death signal phosphatidylserine (PS) independently of apoptosis. In tfhis study, we report that Gal-3, but not Gal-1, induces both PS exposure and apoptosis in primary activated human T cells, whereas both Gal-1 and Gal-3 induce PS exposure in neutrophils in the absence of cell death. Gal-1 and Gal-3 bind differently to the surfaces of T cells and only Gal-3 mobilizes intracellular Ca(2+) in these cells, although Gal-1 and Gal-3 bind their respective T cell ligands with similar affinities. Although Gal-1 does not alter T cell viability, it induces IL-10 production and attenuates IFN-gamma production in activated T cells, suggesting a mechanism for Gal-1-mediated immunosuppression in vivo. These studies demonstrate that Gal-1 and Gal-3 induce differential responses in T cells and neutrophils, and identify the first factor, Gal-3, capable of inducing PS exposure with or without accompanying apoptosis in different leukocytes, thus providing a possible mechanism for galectin-mediated immunomodulation in vivo.

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This work aimed at the isolation and structural/functional characterization of a phospholipase A(2) (CgPLA(2)) from the extract of the anemone Condylactis gigantea. CgPLA2 was isolated with a high purity level through three chromatographic steps, showing pT8.6 and molecular weights of 14,500 and 29,000 for the monomer and dimer, respectively. CgPLA2 showed a high catalytic activity upon fluorescent phospholipids inducing no direct hemolytic activity. This enzyme, which is Ca2+-dependent, showed a lower stability against temperature and pH variations when compared with snake venom enzymes. The enzymatic activity was significantly reduced or completely abolished after chemical modification of CgPLA2 with BPB. Its cDNA was then obtained, with 357 base pairs which codified for a mature protein of 119 amino acid residues. A comparative analysis of the primary structure of CgPLA2 revealed 84%, 61%, 43% and 42% similarity to the PLA2s from Adamsia carciniopados, Nematostella vectensis, Vipera russelli russelli and Both raps jararacussu, respectively. (C) 2010 Elsevier Masson SAS. All rights reserved.

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A variety of nanostructures are being investigated as functional drug carriers for treatment of a wide range of diseases, most notably cardiovascular defects, autoimmune diseases, and cancer. The aim of this present contribution is to evaluate potentially applicable nanomaterials in the diagnosis and treatment of cancer due to their photophysical and photobiological properties and complexation behavior. The delivery systems consisted of chloro-aluminum phthalocyanine associated with beta-cyclodextrin and hydroxypropyl-beta-cyclodextrin. The preparation of the complex and its stoichiometry in an ethanol/buffer (3:1) solution were studied by spectroscopic techniques, which were defined as 1:2. The inclusion complex in the nanometer scale was observed on the basis of changes to the spectroscopic properties. The singlet oxygen production and complex photophysical parameters were determined by measuring luminescence at 1270 nm and by steady state and time resolved spectroscopic, respectively. The preparation of the complex was tested and analyzed with regard to cellular damage by visible light activation. The inclusion complex showed a higher singlet oxygen quantum yield compared with other systems and other photoactive dyes. There was also a reduction in the fluorescence quantum yield compared with the results obtained for zinc phthalocyanine in organic medium. The results reported clearly that the inclusion complex chloro-aluminum phthalocyanine/cyclodextrin showed some changes in its spectroscopy properties leading to better biodistribution and biocompatibility with a potential application in photodynamic therapy, especially in the case of neoplasy. Additionally, it also has non-oncological applications as a drug delivery system.

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In this work the interaction of the antimicrobial peptide indolicidin (IND) and its mutants CP10A and CP11 with a eukaryotic membrane model was examined by molecular dynamics simulations. The aim was to analyse the behaviour of these antimicrobial peptides when they interact with a eukaryotic modelled membrane, thereby obtaining atomic detailed observations that are not experimentally available. In the simulations, the widely studied dipalmitoylphosphatidylcholine hydrated bilayer was used as a eukaryotic membrane model. In agreement with experimental observations, the peptides IND, CP10A, and CP11 insert into the bilayer differently; the peptides that insert more deeply present the major hemolytic activities. The hydrophobic residues are responsible for the insertion, but some Trp residues of the peptides remain at the bilayer/water interface because they interact with the bilayer choline groups by cation-pi interactions that should be important for recognition of eukaryotic membrane by the three studied peptides.

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Background: Data on thyroid involvement in primary antiphospholipid syndrome are scarce and inconclusive. Objectives: The aim of this study was to evaluate the frequency of thyroid dysfunction and antibodies in patients with primary antiphospholipid syndrome ( PAPS) and the association of these alterations with clinical and immunologic features. Methods: The study group included 50 PAPS patients (44 females) with a mean age of 39.7 +/- 11.5 years and mean disease duration of 77.3 +/- 63.5 months. Clinical data related to thyroid dysfunction and PAPS were obtained by chart review, patient interview, and clinical examination. Serum levels of TSH, free T4, antithyroglobulin antibody (TgAb), antithyroperoxidase antibody (TPOAb), thyroid receptor antibody (TRAb), and antiphospholipid autoantibodies were analyzed by standard techniques. Results: We found no hyperthyroidism among patients and found 22% (11 patients) with hypothyroidism in this sample. There were no differences between the latter patients and the euthyroid group about demographic findings, disease duration, thrombotic or obstetric events, and frequency of antiphospholipid antibodies as well as prevalence of thyroid auto antibodies. The prevalence of thyroid autoantibodies found was 6 patients (12%) with TgAb, 5 with TPOAb (10%), and 2 patients (4%) with both TgAb and TPOAb, comprising 18% of positivity of at least one of the auto antibodies. Conclusion: Hypothyroidism is present among 22% of PAPS patients and thyroid autoantibodies in 18% of them. These findings suggest a common pathophysiologic mechanism between antiphospholipid syndrome and autoimmune thyroid diseases.

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Tuberculosis, a polymorphic disease, is a diagnostic challenge, particularly when arises concomitantly to an autoimmune disease such as rheumatoid arthritis (RA). Herein, the authors describe a 33-year-old woman with nodular RA who was being treated with methotrexate, sulfasalazine and corticosteroids and presented with subcutaneous nodules simultaneously with aseptic meningitis. Mycobacterium tuberculosis was identified in cultures from a biopsy of an axillary nodule. The patient also developed polyuria and polydipsia with normal glycemia; antidiuretic hormone (ADH) treatment before and after a 3% saline infusion test was performed and diabetes insipidus was diagnosed. An encephalic MRI showed sellar and suprasellar masses, suggesting central diabetes insipidus (CDI). The patient received standard tuberculosis (TB) treatment for 6 months and also DDAVP (desmopressin acetate) during this period. Control of CDI was observed. A pre-surgical magnetic resonance imaging (MRI) showed no pituitary mass. It is known that intrasellar tuberculoma occurs in only 1% of TB patients. TB should be considered in the differential diagnosis of CDI, especially in immunosupressed patients and in countries where this infection is a serious public health problem.

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Hemochromatosis can be classified as (a) primary, when it originates from a genetic disturbance that promotes the increase of iron absorption, or (b) secondary, when it relates to chronic diseases or to multiple transfusions. The distribution of iron accumulation differs between these two forms; therefore, they can be distinguished by using imaging methods in the majority of cases. Magnetic resonance (MR) imaging is the most sensitive and specific imaging modality in the diagnosis of hemochromatosis. The susceptibility effect caused by the accumulation of iron leads to signal loss in the affected tissues, particularly with the T2*-weighted sequences, which makes the diagnosis of iron overload possible. By using MR imaging techniques, it is possible to estimate the hepatic iron concentration in a noninvasive way, thereby avoiding repeated biopsies. Hemochromatosis can lead to complications, such as a higher frequency of neoplasia, particularly the development of hepatocellular carcinoma. Other neoplasms, such as colorectal tumors, are also associated. Complications related to the treatment of chronic anemia include the appearance of peliosis hepatis and tumors, which can regress after the suspension of treatment with drugs. Knowledge of the disease and of the patterns of iron deposition in patients with iron overload enables not only diagnosis, but also treatment, follow-up, and the detection of possible complications by using imaging methods. (C) RSNA, 2009 . radiographics.rsna.org

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High nutritional levels of iodine may induce a higher prevalence of autoimmune thyroiditis,hypothyroidism, goiter, as well as hyperthyroidism, mostly in the elderly. This study assessed thyroid volume and ultrasonographic abnormalities as well as urinary iodine excretion (UIE) in 964 schoolchildren living in an iodine-sufficient area in southern Brazil. Thyroid volume correlated with age and body surface area in boys and girls. In 76.8% of the children, UIE was above 300 mu g/l, with higher levels among boys compared to girls (484.2 mu g/l vs 435.3 mu g/l, p <0.001). Thyroid abnormalities detected by ultrasonography included hemiagenesis (0.5%), nodules (0.2%), cysts (0.7%), and hypoechogenicity (11.7%). Goiter was present in 1.9% of the children. Hypoechogenicity, a relevant marker of autoimmune thyroiditis, was the most common abnormality found in our study, and this may be linked to excessive iodine intake.

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Rheumatoid arthritis (RA) is a systemic inflammatory autoimmune disease causing significant social, medical, and economic impact. Several therapeutic regimens are available within the medical arsenal. The rational and reasoned use of various medications approved for their treatment is imperative. This study aimed to evaluate how Brazilian rheumatologists use the drugs available to combat the disease. For this, 128 Brazilian rheumatologists from public and private health services responded to an 18-item questionnaire, sent over the Internet, about different situations of drug treatment of RA. The answers helped to confirm the trends among Brazilian rheumatologists in the drug treatment of RA. The study results have shown that most Brazilian rheumatologists follow the guidelines and consensus established by the Brazilian Society of Rheumatology for the treatment of RA. A small proportion, however, start the biologic therapy in early stages of the disease, including the very early stage, as the first treatment option. Most experts use corticosteroids in low doses early in the treatment. Conclusions: This study confirms that the majority but not all Brazilian rheumatologists follow, in their daily practice, established guidelines and consensus for the treatment of RA. However, it also shows that some few rheumatologists start with anti-tumor necrosis factor therapy in very early arthritis independently of disease severity or prognostic factors.

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Background and objectives: As well as being a marker of body iron stores, serum ferritin (sFerritin) has also been shown to be a marker of inflammation in hemodialysis (HD) patients. The aim of this study was to analyze whether sFerritin is a reliable marker of the iron stores present in bone marrow of HD patients. Design: Histomorphometric analysis of stored transiliac bone biopsies was used to assess iron stores by determining the number of iron-stained cells per square millimeter of bone marrow. Results: In 96 patients, the laboratory parameters were hemoglobin = 11.3 +/- 1.6 g/dl, hematocrit = 34.3 +/- 5%, sFerritin 609 +/- 305 ng/ml, transferrin saturation = 32.7 +/- 22.5%, and C-reactive protein (CRP) = 0.9 +/- 1.4 mg/dl. sFerritin correlated significantly with CRP, bone marrow iron, and time on HD treatment W = 0.006, 0.001, and 0.048, respectively). The independent determinants of sFerritin were CRP (beta-coef = 0.26; 95% CI = 24.6 to 132.3) and bone marrow iron (beta-coef = 0.32; 95% CI = 0.54 to 2.09). Bone marrow iron was higher in patients with sFerritin >500 ng/ml than in those with sFerritin :5500 ng/ml. In the group of patients with sFerritin :5500 ng/ml, the independent determinant of sFerritin was bone marrow iron (beta-coef = 0.48, 95% CI = 0.48 to 1.78), but in the group of patients with sFerritin >500 ng/ml, no independent determinant of sFerritin was found. Conclusions: sFerritin adequately reflects iron stores in bone marrow of HD patients.

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Considering that mycobacterial heat-shock protein 65 (hsp65) gene transfer can elicit a profound antitumoral effect, this study aimed to establish the safety, maximum-tolerated dose (MTD) and preliminary efficacy of DNA-hsp65 immunotherapy in patients with advanced head and neck squamous cell carcinoma (HNSCC). For this purpose, 21 patients with unresectable and recurrent HNSCC were studied. Each patient received three ultrasound-guided injections at 21-day intervals of: 150, 600 or 400 mu g of DNA-hsp65. Toxicity was graded according to CTCAE directions. Tumor volume was measured before and after treatment using computed tomography scan. The evaluation included tumor mass variation, delayed-type hypersensitivity response and spontaneous peripheral blood mononuclear cell proliferation before and after treatment. The MTD was 400 mg per dose. DNA-hsp65 immunotherapy was well tolerated with moderate pain, edema and infections as the most frequent adverse effects. None of the patients showed clinical or laboratory alterations compatible with autoimmune reactions. Partial response was observed in 4 out of 14 patients who completed treatment, 2 of which are still alive more than 3 years after the completion of the trial. Therefore, DNA-hsp65 immunotherapy is a feasible and safe approach at the dose of 400 mg per injection in patients with HNSCC refractory to standard treatment. Further studies in a larger number of patients are needed to confirm the efficacy of this novel strategy.

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The case reported refers to a patient who developed status epilepticus in the day of her third dose of hepatitis B vaccination and we review the literature on this subject. A 12 year-old girl, without a relevant previous history, taking no drugs, developed a seizure attack followed by unconsciousness, and eventually died after three days of her third dose of hepatitis B (HB) vaccination. Autopsy study revealed cerebral edema with congestion and herniation and diffuse interstitial type pneumonitis. There seem to be a straight forward time relationship between the third HB vaccine, the event of convulsion and the sudden death of the patient. We suggest that, in some cases, vaccination may be the triggering factor for autoimmune and neurological disturbances in genetically predisposed individuals and physicians should be aware of this possible association. (c) 2007 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.