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Biomedical subjects

L A Magna

Publications and source records attributed to L A Magna.

32 records · Page 2Linked to original sources
PubMed1984

NADH-methemoglobin reductase and methemoglobinemia among leprosy patients.

The NADH-methemoglobin reductase activity as well as hemoglobin and methemoglobin levels were investigated in blood samples of 182 adult leprosy patients and 137 Brazilian army enlisted men. The level of sulfones in the blood samples of the leprosy patients, all of them ingesting a daily dose of 100 mg dapsone, was also investigated. The mean value of NADH-methemoglobin reductase activity exhibited by the leprosy patients did not differ from that observed among the healthy individuals. However, the variance of the former group was significantly higher than that observed among the healthy subjects. As a consequence, the proportion of individuals showing a partial deficiency of NADH-methemoglobin reductase was significantly higher among the leprosy patients (22.5%) than among the healthy individuals (2.9%). The activity of this enzyme among the leprosy patients was negatively correlated to the hemoglobin level and slightly positively correlated to age. The concentration of methemoglobin among the leprosy patients was slightly but significantly higher as compared to the healthy individuals. The increase of the methemoglobin level among the leprosy patients was influenced by the amount of sulfones in the blood. However, no case in which dapsone was ingested in a daily dose of 100 mg presented the signs or symptoms of toxic methemoglobinemia.

Adult↗
PubMed1983

[Thalassemia and Hansen's disease].

The beta-thalassemia trait was investigated among 165 Brazilians who were unmixed Italian descendants (80 Virchowian patients and 85 normal controls, composed of universitary students). The frequency of the beta-thalassemia trait was 6.25% among the Virchowian patients and 5.88% in the control group. In spite of the similar geographical distribution of both hanseniasis and the gene for beta-thalassemia in Asia, the present data does not support the hypothesis that hanseniasis might have contributed to maintain high prevalence of this allele by selection favouring beta-thalassemia trait.

Female↗
PubMedDate not supplied

Genetic variation and relationships at six VNTR loci in two distinct sample populations in Brazil.

BACKGROUND: The Brazilian population has been the focus of intensive genetic study due to admixture characteristics whereas there are few reports on the variability of VNTR loci in Brazil. PRIMARY OBJECTIVE: The aim of this study was to analyse genetic parameters in sample populations from two geographically distant regions: São Luis City, in Maranhão State and Campinas City, in São Paulo State. We investigated if distinct colonization influences could produce detectable differences in genetic background. SUBJECT AND METHODS: DNA samples from peripheral drained blood were obtained from unrelated individuals who underwent paternity testing. Allelic variation in six VNTR loci (D2S44, D4S139, D5S110, D8S358, DI0S28 and D17S79) was evaluated. The results were compared to reference databases available for general Latin-derived European and African-American populations as well as for other Brazilian groups. RESULTS: This study reveals that forensic population parameters did not show differences among regions, although we detected admixture values varying between the south-east and north-east of Brazil. CONCLUSIONS: Differences between the two samples are probably due to different admixture proportions of European- and African-derived alleles in each region: both populations are in Hardy Weinberg equilibrium. In addition, the allelic frequency for all loci, in both populations, can be used as database for forensic purposes.

Alleles↗
PubMedDate not supplied

A clinical, epidemological, laboratorial, histological and ultrasonographical evaluation of anti-HCV EIA-2 positive blood donors.

Between 1992 and 1997, 790 blood donors with anti-HCV EIA-2 strongly reagent (relationship between the sample optical density/cut-off > 3) detected at the blood bank serological screening, were evaluated in ambulatory environment. They were all negative for Chagas disease, syphilis, hepatitis B (HBsAg) and AIDS. Blood samples were collected at the first ambulatorial evaluation, for hemogram, biochemical tests and new serological tests for HCV (anti-HCV EIA-2). In blood samples of 226 repeatedly reagent anti-HCV EIA-2 blood donors, supplementary "immunoblot" test for HCV (RIBA-2) was used. In 209 donors, the presence of HCV-RNA was investigated by the PCR test. The abdominal ultrasonography was realized in 366 donors. In 269 patients liver biopsy was performed for the histopathological study. The follow-up of blood donors showed that 95.6% were repeatedly EIA-2 reagent, 94% were symptomless and denied any hepatitis history, with only 2% mentioning previous jaundice. In 47% of this population at least one risk factor has been detected for the HCV transmission, the use of intravenous drugs being the main one (27.8%). Blood transfusion was the second factor for HCV transmission (27.2%). Hepatomegaly was detected in 54% of the cases. Splenomegaly and signs of portal hypertension have seldom been found in the physical examination, indicating a low degree of hepatic compromising in HCV. Abdominal ultrasound showed alterations in 65% of the subjects, being the steatosis the most frequent (50%). In 83. 5% of the donors submitted to the liver biopsy, the histopathological exam showed the presence of chronic hepatitis, usually classified as active (89%) with mild or moderate grade in most of the cases (99.5%). The histopathological exam of the liver was normal in 1.5% of blood donors. The RIBA-2 test and the HCV-RNA investigation by PCR were positive in respectively 91.6 and 75% of the anti-HCV EIA-2 reagent donors. The HCV-RNA research was positive in 82% of the RIBA-2 positive subjects, in 37.5% of the indeterminate RIBA-2 donors and in 9% of the negative RIBA-2 donors. Chronic hepatitis has also been observed in 50% of the histopathological exams of the anti-HCV EIA-2 reagent donors which were indeterminate RIBA-2. Among 18 blood donors with minimal changes histopathological exam 11 (61%) were HCV-RNA positive. Our blood donors anti-HCV reagent generally had clinical, laboratorial and histopathological features observed in patients with chronic HCV hepatitis and a high proportion could be identified in interviews and medical evaluation realized in blood blanks. Generally, these HCV infected donors are identified and discharged only by the serological tests results.

Adolescent↗
PubMedDate not supplied

[Community genetics and hemophilia in a Brazilian population].

Hemophilia is an important hemorrhagic disease in Brazil, affecting about 1 out of every 10,000 males. Patient's self-perception of hemophilia and interaction with the community are relevant to the clinical management of this disease. We investigated several social, psychological, and community aspects of hemophilia in a Brazilian population (Campinas, São Paulo State), interviewing 30 hemophiliac males, a control sample comprised of 73 non-hemophiliac brothers, and 641 individuals from the community. According to our results, more severe social disability in the hemophiliac patient was related to economic factors, mainly unemployment; however, no difference was found in relation to marital status, reproduction, or education. Self-perception of changes in health and lifestyle by individuals with hemophilia showed frequent self-stigmatization, along with depression, anxiety, and insecurity. The community showed a widespread lack of familiarity with hemophilia (49%), viewing people with hemophilia with the kinds of prejudices often observed in relation to people with infectious diseases, like AIDS. The paper concludes by recommending that a community-based program be implemented to improve the social adjustment status of individuals with hemophilia.

Adult↗
PubMedDate not supplied

Immunohistochemical study of basement membrane collagen IV in uterine cervix carcinoma.

CONTEXT: The integrity of basement membrane (BM) is damaged during the evolution of a benign or potentially malignant lesion into a malignant one, in which it may undergo several degrees of discontinuity as a necessary condition for the invasive process. Immunostaining for collagen IV, which is exclusively found in BM, has been used to evaluate its formation in neoplastic and benign lesions of several organs. OBJECTIVE: To investigate BM continuity pattern in squamous carcinoma "in situ" (CIS), microinvasive (MIC) and invasive (IC) squamous cell carcinoma of the uterine cervix, and to find out if BM expression could be useful in the diagnosis of early stromal invasion (MIC). DESIGN: Archival material between 1988 and 1993 was studied at the Pathological Anatomy Department-Unicamp. PROCEDURES: The selected cases, previously formalin fixed and paraffin embedded, were reviewed retrospectively by submitting them to immunohistochemical study via the avidin-biotin-peroxidase method using a monoclonal antibody anticollagen IV. RESULTS: In all, 17 cases of CIS, 16 of MIC and 21 of IC were evaluated. All IC cases showed evident BM discontinuity, either focal or diffuse. In the CIS group, a continuous BM pattern was predominant, being focally disrupted in only 2/17 cases (11.8%). The MIC group showed an intermediate pattern, but with a clear tendency to BM discontinuity in 10/16 cases (62.5%). Inflammatory infiltrate, a variable also studied, cannot be considered responsible for BM discontinuity, since there was no statistical correlation between them. CONCLUSION: We conclude that immunostaining for collagen IV may contribute to the diagnosis of stromal invasion by BM discontinuity.

Basement Membrane↗
PubMedDate not supplied

Relationship between HLA antigens and infectious agents in contributing towards the development of Graves' disease.

Graves' disease (GD) is an autoimmune thyroid disorder which is associated with the human leucocyte antigens HLA-DR3 and DQA1* O501 in Caucasians. We have explored the possibility that some patients with certain HLA specificities develop anti-HLA antibodies which are correlated with environmental factors that may contribute to the development of GD. We studied 40 GD patients and 157 healthy individuals (controls). Serology was used to type HLA-A, -B, -Cw, and -DR antigens. The frequencies of these antigens in relation to lymphocytotoxic anti-HLA-A-B-Cw-DR antibodies and two environmental factors (Yersinia enterocolitica and Coxsackie B virus) were determined. The frequencies of HLA-B15, -B21 and DR3 antigens were increased, whereas HLA-DR5 antigen was decreased in GD patients. A significant association between HLA-DR3 antigen and lymphocytotoxic antibodies was observed, i.e., IgGs from GD patients were cytotoxic to HLA-DR3+ normal B cells. Following absorption with Yersinia enterocolitica or Coxsackie-B-virus, only Coxsackie-B virus completely inhibited the lymphocytotoxic reactions against HLA-DR3+ B cells. Besides confirming the association of HLA-DR3 with GD, this study also suggests the role of Coxsackie-reactive HLA-DR3 antibodies as contributing factors to the pathogenesis of the disease.

Adolescent↗
PubMedDate not supplied

Acid suppression with ranitidine plus oral triple therapy improves ulcer healing but not Helicobacter pylori eradication.

BACKGROUND/AIMS: To evaluate whether the addition of 2 weeks of ranitidine to a 1-week oral triple therapy (OTT) regimen improved ulcer healing and H. pylori eradication. METHODOLOGY: Two hundred and eleven consecutive patients with an endoscopic diagnosis of active duodenal ulcer (DU) and a positive antrum biopsy for H. pylori were enrolled. Those attending the Hospital Vera Cruz (Group A, n=142) received a 14-day course of ranitidine (150 mg after breakfast and dinner) plus a 1-week OTT, consisting of bismuth subcitrate, (240 mg after the 3 meals), tetracycline (500 mg, 10 min before the three meals and at bedtime), and furazolidone (200 mg after breakfast and dinner). Patients from the Hospital das Clinicas (Group B, n=69) received the same OTT as Group A but without ranitidine. Patients underwent endoscopy again on average 40 days (range: 30-60 days) after completing therapy in order to assess ulcer healing and H. pylori status. RESULTS: Both schedules were equally efficient in eradicating H. pylori with 90% (128/142) eradication in group A, and 84% (58/69) in group B (p=0.2). In contrast, the addition of ranitidine to OTT improved ulcer healing when compared with OTT alone (96%, 137/142, vs. 70%, 48/69; p<0.001). CONCLUSIONS: Our results demonstrate that the association of acid suppression, obtained with 2 week ranitidine administration with OTT improved ulcer healing but did not enhance H. pylori eradication.

Adolescent↗