107 resultados para Machado, Ana Maria, 1941- Crítica e interpretação
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The spray drying method was used to prepare luminescent microspheres. These microspheres were prepared by spraying an aqueous solution of dextrin and an europium(III) complex with subsequent drying in a hot medium. The spray dried powder was characterized by scanning electron microscopy (SEM) and photoluminescence spectroscopy (PL). Particle size distribution was estimated from SEM images. The ultrasonic spray drying technique was successfully applied to yield a microparticulated and red luminescent powder composed by the [Eu(dpa)(3)](3-) stop (dpa = dipicolinic acid) complex incorporated in dextrin microspheres.
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We have established a proteoliposome system as an osteoblast-derived matrix vesicle (MV) biomimetic to facilitate the study of the interplay of tissue-nonspecific alkaline phosphatase (TNAP) and NPP1 (nucleotide pyrophosphatase/phosphodiesterase-1) during catalysis of biomineralization substrates. First, we studied the incorporation of TNAP into liposomes of various lipid compositions (i.e. in pure dipalmitoyl phosphatidylcholine (DPPC), DPPC/dipalmitoyl phosphatidylserine (9:1 and 8:2), and DPPC/dioctadecyl-dimethylammonium bromide (9:1 and 8:2) mixtures. TNAP reconstitution proved virtually complete in DPPC liposomes. Next, proteoliposomes containing either recombinant TNAP, recombinant NPP1, or both together were reconstituted in DPPC, and the hydrolysis of ATP, ADP, AMP, pyridoxal-5`-phosphate (PLP), p-nitrophenyl phosphate, p-nitrophenylthymidine 5`-monophosphate, and PP(i) by these proteoliposomes was studied at physiological pH. p-Nitrophenylthymidine 5`-monophosphate and PLP were exclusively hydrolyzed by NPP1-containing and TNAP-containing proteoliposomes, respectively. In contrast, ATP, ADP, AMP, PLP, p-nitrophenyl phosphate, and PPi were hydrolyzed by TNAP-, NPP1-, and TNAP plus NPP1- containing proteoliposomes. NPP1 plus TNAP additively hydrolyzed ATP, but TNAP appeared more active in AMP formation than NPP1. Hydrolysis of PPi by TNAP-, and TNAP plus NPP1- containing proteoliposomes occurred with catalytic efficiencies and mild cooperativity, effects comparable with those manifested by murine osteoblast-derived MVs. The reconstitution of TNAP and NPP1 into proteoliposome membranes generates a phospholipid microenvironment that allows the kinetic study of phosphosubstrate catabolism in a manner that recapitulates the native MV microenvironment.
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The evolution of the historiography of psychology in Brazil is surveyed, to describe how the field has evolved from the seminal works of the pioneer, mostly self-taught, psychologists, to the now professional historians working from a variety of theoretical models and methods of inquiry. The first accounts of the history of psychology written by Brazilians and by foreigners are surveyed, as well as the recent works made by researchers linked to the Work Group on the History of Psychology of the Brazilian Association of Research and Graduate Education in Psychology and published in periodicals such as Memorandum and Mnemosine. The present historiography focuses mainly the relationship of psychological knowledge to specific social and cultural conditions, emphasizing themes such as women`s participation in the construction of the field, the development of psychology as a science and as a profession in education and health, and the development of psychology as an expression of Brazilian culture and of the experience of resistance of local communities to domination. To reveal this process of identity construction, a cultural historiography is an important tool, coupled with methodological pluralism.
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The Jabirian Corpus refers to the K. Thahirat Al-`Iskandar, ""The Book of the Treasure of Alexander"" (hereafter BTA), as one of several forgeries suggesting that alchemical secrets were hidden in inscriptions in various places. The book was neglected until 1926, when Julius Ruska discussed it in his work on the Emerald Tablet, placing the BTA within the literature related to the development of Arabic alchemy. His preliminary study became an essential reference and encouraged many scholars to work on the BTA in the following decades. Some years ago, we completed the first translation of the BTA into a Western language. The work was based on the acephalous Escorial manuscript, which we identified as a fourteenth-century copy of the BTA. This manuscript is peculiar, as part of it is encoded. After finishing our translation, we started to establish the text of the BTA. At present, the text is in process of fixation-to be followed by textual criticism-and has been the main focus of a thorough study of ours on medieval hermeticism and alchemy. A sample of the work currently in progress is presented in this paper: an analysis of the variations between different manuscripts along with a study and English translation of its alchemical chapter.
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Background:. Although the role of the lung alveolar macrophage (AM) as a mediator of acute lung injury (ALI) after lung ischemia/reperfusion (I/R) has been suggested by animal experiments, it has not been determined whether AMs mediate ALI after intestinal I/R. The objective of this study was to determine the effect of AM elimination on ALI after intestinal I/R in rats. Mwthods: Male Wistar rats (n = 90) were randomly divided into three groups: the clodronate-liposomes (CLOD-LIP) group received intratracheal treatment with CLOD-LIP; the liposomes (LIP) group received intratracheal treatment with LIP; and the nontreated (UNTREAT) group received no treatment. Twenty-four hours later each group was randomly divided into three subgroups: the intestinal I/R subgroup was subjected to 45-minute intestinal ischemia and 2-hour reperfusion; the laparotomy (LAP) subgroup was subjected to LAP and sham procedures; the control (CTR) subgroup received no treatment. At the end of reperfusion, ALI was quantitated in all the animals by the Evans blue dye (EBD) method. Results: ALI values are expressed as EBD lung leakage (mu g EBD/g dry lung weight). EBD lung leakage values in the CLOD-LIP group were 32.59 +/- 12.74 for I/R, 27.74 +/- 7.99 for LAP, and 33.52 +/- 10.17 for CTR. In the LIP group, lung leakage values were 58.02 +/- 18.04 for I/R, 31.90 +/- 8.72 for LAP, and 27.17 +/- 11.48 for CTR. In the UNTREAT group, lung leakage values were 55.60 +/- 10.96 for I/R, 35.99 +/- 6.89 for LAP, and 30.83 +/- 8.41 for CTR. Within each group, LAP values did not differ from CTR values. However, in the LIP and UNTREAT groups, values for both the LAP and CTR subgroups were lower than values for the I/R subgroup (p < 0.001). The CLOD-LIP I/R subgroup value was less (p < 0.001) than the I/R subgroup values in the LIP and UNTREAT groups. These results indicated that I/R provokes ALI that can be prevented by CLOD-LIP treatment, and further suggested that AMs are essential for ALI occurrence induced by intestinal I/R in rats.
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Two humanized monoclonal antibody constructs bearing the same variable regions of an anti-CD3 monoclonal antibody, whole IgG and FvFc, were expressed in CHO cells. Random and site-specific integration were used resulting in similar expression levels. The transfectants were selected with appropriate selection agent, and the surviving cells were plated in semi-solid medium for capture with FITC-conjugated anti-human IG antibody and picked with the robotic ClonePix FL. Conditioned media from selected clones were purified by affinity chromatography and characterized by SDS-PAGE, Western-blot, SEC-HPLC, and isoelectric focusing. Binding to the target present in healthy human mononuclear cells was assessed by flow cytometry, as well as by competition between the two constructs and the original murine monoclonal antibody. The humanized constructs were not able to dislodge the murine antibody while the murine anti-CD3 antibody could dislodge around 20% of the FvFc or IgG humanized versions. Further in vitro and in vivo pre-clinical analyses will be carried out to verify the ability of the humanized versions to demonstrate the immunoregulatory profile required for a humanized anti-CD3 monoclonal antibody.
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Background: The prognostic significance of spontaneous regression in melanoma, especially thin lesions, has been a controversial issue for the past 20 years, although recent studies suggest that extensive and late regression may be related to worse prognosis. Many data suggest that lymphangiogenesis predicts metastatic spread in melanoma. Methods: We have quantified lymphatic microvascular density (LMVD) in thin (<= 1.0 mm) superficial spreading melanomas comparing regressive and nonregressive melanomas, regressive and nonregressive areas from the same tumor, and early and late histological stages of regression in the same tumor. In addition, we tried to correlate lymphangiogenesis and tumor growth phase. We conducted histological examinations and immunohistochemical analyses using monoclonal antibody D2-40 with subsequent quantification by image analysis of 37 melanomas, 16 regressive and 21 nonregressive (controls). Results: We found higher LMVD in the late stage of regression compared with nonregressive area (internal control) of regressive melanomas. Conclusions: Our study suggest that the late stage of spontaneous regression in thin melanomas may be related to worse prognosis as it showed higher LMVD, and evidence shows that this is related with increased risk of metastatic spread. But this supposition must be confirmed by a longer follow-up for detection of lymph node metastases.
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We aimed to investigate the vascular effects of hyperhomocysteinemia (HHcy) on carotid arteries from young and adult rats. With this purpose young and adult rats received a solution of DL-homocysteine-thiolactone (1 g/kg body weight/day) in the drinking water for 7, 14 and 28 days. Increase on plasma homocysteine occurred in young and adult rats treated with DL-homocysteine-thiolactone in all periods. Vascular reactivity experiments using standard muscle bath procedures showed that HHcy enhanced the contractile response of endothelium-intact, carotid rings to phenylephrine in both young and adult rats. However, in young rats, the increased phenylephrine-induced contraction was observed after hyperhomocysteinemia for 14 and 28 days, whereas in adult rats this response was already apparent after 7 day treatment. HHcy impaired acetylcholine-induced relaxation in arteries from adult but not young rats. The contraction induced by phenylephrine in carotid arteries in the presence of Y-27632 was reversed to control values in arteries from young but not adult rats with hyperhomocysteinemia. HHcy did not alter the contraction induced by CaCl(2) in carotid arteries from young rats, but enhanced CaCl(2)-induced contraction in the arteries from adult rats. HHcy increased the basal levels of superoxide anion in arteries from both groups. Finally, HHcy decreased the basal levels of nitrite in arteries from adult but not young rats. The major new finding of the present work is that arteries from young rats are more resistant to vascular changes evoked by HHcy than arteries from adult rats. Also, we verified that the enhanced vascular response to phenylephrine observed in carotid arteries of DL-homocysteine thiolactone-treated rats is mediated by different mechanisms in young and adult rats. (C) 2010 Published by Elsevier Inc.
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Background: There are few studies on HIV subtypes and primary and secondary antiretroviral drug resistance (ADR) in community-recruited samples in Brazil. We analyzed HIV clade diversity and prevalence of mutations associated with ADR in men who have sex with men in all five regions of Brazil. Methods: Using respondent-driven sampling, we recruited 3515 men who have sex with men in nine cities: 299 (9.5%) were HIV-positive; 143 subjects had adequate genotyping and epidemiologic data. Forty-four (30.8%) subjects were antiretroviral therapy-experienced (AE) and 99 (69.2%) antiretroviral therapy-naive (AN). We sequenced the reverse transcriptase and protease regions of the virus and analyzed them for drug resistant mutations using World Health Organization guidelines. Results: The most common subtypes were B (81.8%), C (7.7%), and recombinant forms (6.9%). The overall prevalence of primary ADR resistance was 21.4% (i.e. among the AN) and secondary ADR was 35.8% (i.e. among the AE). The prevalence of resistance to protease inhibitors was 3.9% (AN) and 4.4% (AE); to nucleoside reverse transcriptase inhibitors 15.0% (AN) and 31.0% (AE) and to nonnucleoside reverse transcriptase inhibitors 5.5% (AN) and 13.2% (AE). The most common resistance mutation for nucleoside reverse transcriptase inhibitors was 184V (17 cases) and for nonnucleoside reverse transcriptase inhibitors 103N (16 cases). Conclusions: Our data suggest a high level of both primary and secondary ADR in men who have sex with men in Brazil. Additional studies are needed to identify the correlates and causes of antiretroviral therapy resistance to limit the development of resistance among those in care and the transmission of resistant strains in the wider epidemic.
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Endomyocardial fibrosis (EMF) is a restrictive cardiomyopathy of unknown etiology prevalent in tropical regions affecting the inflow tract and apex of one or both ventricles, which show fibrous thickening of the endocardium and adjacent myocardium. Surgical treatment is recommended for patients in functional classes III or IV (New York Heart Association). The gross and histological features of the heart have been comprehensively studied in autopsies, but studies in surgical samples are still lacking. Histological and immunohistochemical features of EMF in surgical samples collected from 32 patients were described and correlated with clinical data. Polymerase chain reaction (PCR) and reverse transcription-PCR, performed on formalin fixed endomyocardial samples, were used retrospectively to detect genomes of certain cardiotropic viruses and Toxoplasma gondii. Ventricular endocardium was thickened by superficial acellular hyaline collagen fibers type I and III, with predominance of the former type. Besides fibrosis, a chronic inflammatory process and an anomalous lymphatic rich vascular pattern were observed in the deep endocardium, connected to the terminal coronary circulation of the myocardium, which might be an important pathological finding concerning EMF pathogenesis. Molecular analysis of the endomyocardium revealed high incidence of cardiotropic infective agents (6/12, 50%); however, their role in the disease pathogenesis is still controversial.
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Non-communicable diseases (NCDs) have become a major health priority in Brazil-72% of all deaths were attributable to NCDs in 2007. They are also the main source of disease burden, with neuropsychiatric disorders being the single largest contributor. Morbidity and mortality due to NCDs are greatest in the poor population. Although the crude NCD mortality increased 5% between 1996 and 2007, age-standardised mortality declined by 20%. Declines were primarily for cardiovascular and chronic respiratory diseases, in association with the successful implementation of health policies that lead to decreases in smoking and the expansion of access to primary health care. Of note, however, the prevalence of diabetes and hypertension is rising in parallel with that of excess weight; these increases are associated with unfavourable changes of diet and physical activity. Brazil has implemented major policies for the prevention of NCDs, and its age-adjusted NCD mortality is falling by 1.8% per year. However, the unfavourable trends for most major risk factors pose an enormous challenge and call for additional and timely action and policies, especially those of a legislative and regulatory nature and those providing cost-effective chronic care for individuals affected by NCDs.
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Bariatric surgery before pregnancy may help prevent obesity-related gestational complications. However, maternal malnutrition is not without potential risks during pregnancy. The objective was to evaluate the influence of time to conception after silastic ring Roux-en-Y gastric bypass (SRYGB) on maternal anemia. Patients who underwent SRYGB for morbid obesity and who subsequently became pregnant were followed up at the prenatal. Thirty pregnancies occurred between July 2001 and September 2009. The patients were analyzed according to time to conception after bariatric surgery: 17 patients with time to conception < 4 years (48 months) and 13 patients with a parts per thousand yen4 years. First trimester hemoglobin levels were significantly lower in patients with time to conception a parts per thousand yen4 years (48 months) (median 9.6 g/dL, range 5.8-13.2 g/dL) than in patients with time to conception < 4 years (median 11.1 g/dL, range 9.8-13.6 g/dL; p = 0.047). The need for intravenous iron therapy or packed red cell transfusion was significantly more frequent among women who became pregnant a parts per thousand yen4 years after SRYGB compared to < 4 years (30.8% vs. 0%, p = 0.026). Pregnancy after 4 years of SRYGB is associated with maternal anemia and the need for more strict iron supplementation.
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Objective. Chronic rhinosinusitis (CRS) is a risk factor for asthma exacerbations and is associated with greater clinical severity. Discrepancies may exist between CRS clinical diagnosis and data from paranasal sinus (PS) X-ray or computed tomography (CT) scans. The objective was to compare PS involvement using low-dose CT and plain X-ray in allergic asthmatic patients with rhinitis. Methods. Patients underwent PS radiography in the frontal and mentonian positions and low-dose CT consisting of six to eight coronal scans performed on the central region of the sphenoidal, ethmoidal, maxillary, and frontal sinuses. Possible results for each sinus were a normal aspect or the presence of mucosal thickening, opacification, and/or air-fluid level. Results. Eighty-five (93.4%) of 91 study patients had radiological changes on radiography or CT. In only six (6.6%) were both tests normal. The maxillary was the most involved sinus by both methods. Simultaneous PS abnormalities were observed in 40.5% on X-ray and 56.7% on CT. For the frontal, ethmoidal, and sphenoidal sinuses, the proportion of normal results differed significantly between X-ray and CT: 80.2% versus 89%, 76.9% versus 63.7% and 96.7% versus 70.3%, respectively (p <.05). Agreement was over 70% for the maxillary and frontal sinuses. CT also provided a better diagnosis of air-fluid level changes than X-ray. Conclusions. Low-dose CT significantly showed larger number of normal PS results and diagnosed more severe PS lesions. As the determination of true sinus severity lesion impacts in asthma control, low-dose CT may replace PS plain X-ray and conventional CT to support better clinical decisions.
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Background. Subsequent ischaemic episodes may induce renal resistance. P21 is a cell cycle inhibitor that may be induced by oxygen-free radicals and may have a protective effect in ischaemic acute kidney injury (AKI). This study aimed at evaluating the role of oxidative stress and p21 on tubular resistance in a model of acquired resistance after renal ischaemia and in isolated renal tubules. Methods. Wistar rats were divided into: Group 1-sham; Group 2-sham operated and after 2 days submitted to 45-min ischaemia; and Group 3-45-min ischaemia followed after 2 days by a second 45-min ischaemia. Plasma urea was evaluated on Days 0, 2 and 4. Serum creatinine, creatinine clearance and oxidants (thiobarbituric acid-reactive substances) were determined 48 h after the second procedure (Day 4). Histology, immunohistochemistry for lymphocytes (CD3), macrophages (ED1), proliferation (PCNA) and apoptosis (TUNEL) were also evaluated. Rat proximal tubules (PTs) were isolated by collagenase digestion and Percoll gradient from control rats and rats previously subjected to 35 min of ischaemia. PTs were submitted to 15-min hypoxia followed by 45-min reoxygenation. Cell injury was assessed by lactate dehydrogenase release and hydroperoxide production (xylenol orange). Results. Ischaemia induced AKI in Group 2 and 3 rats. Subsequent ischaemia did not aggravate renal injury, demonstrating renal resistance (Group 3). Renal function recovery was similar in Group 2 and 3. Plasma and urine oxidants were similar among in Group 2 and 3. Histology disclosed acute tubular necrosis in Group 2 and 3. Lymphocyte infiltrates were similar among all groups whereas macrophages infiltrate was greater in Group 3. Cell proliferation was greater in Group 2 compared with Group 3. Apoptosis was similar in groups 2 and 3. The p21 expression was increased only in Group 3 whereas it was similar in groups 1 and 2. PTs from the ischaemia group were sensitive to hypoxia but resistant to reoxygenation injury which was followed by lower hydroperoxide production compared to control PT. Conclusion. Renal resistance induced by ischaemia was associated with cell mechanism mediators involving oxidative stress and increased p21 expression.