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Biomedical subjects

R Gonçalves

Publications and source records attributed to R Gonçalves.

18 recordsLinked to original sources

Involvement of the major histocompatibility complex region in the genetic regulation of circulating CD8 T-cell numbers in humans.

Variability in T-lymphocyte numbers is partially explained by a genetic regulation. From studies in animal models, it is known that the Major Histocompatibility Complex (MHC) is involved in this regulation. In humans, this has not been shown yet. The objective of the present study was to test the hypothesis that genes in the MHC region influence the regulation of T-lymphocyte numbers. Two approaches were used. Association studies between T-cell counts (CD4(+) and CD8(+)) or total lymphocyte counts and HLA class I alleles (A and B) or mutations in the HFE (C282Y and H63D), the hemochromatosis gene, in an unrelated population (n = 264). A second approach was a sibpair correlation analysis of the same T-cell counts in relation to HLA-HFE haplotypes in subjects belonging to 48 hemochromatosis families (n = 456 sibpairs). In the normal population, results showed a strong statistically significant association of the HLA-A*01 with high numbers of CD8(+) T cells and a less powerful association with the HLA-A*24 with low numbers of CD8(+) T cells. Sibpair correlations revealed the most significant correlation for CD8(+) T-cell numbers for sibpairs with HLA-HFE-identical haplotypes. This was not observed for CD4(+) T cells. These results show that the MHC region is involved in the genetic regulation of CD8(+) T-cell numbers in humans. Identification of genes responsible for this control may have important biological and clinical implications.

Adolescent↗

Modelling of ex vivo expansion/maintenance of hematopoietic stem cells.

In this study, we described the modelling of the expansion/maintenance of human hematopoietic stem/progenitor cells from adult human bone marrow. CD 34(+)-enriched cell populations from bone marrow were cultured in the presence and absence of human stroma in serum-free media containing bFGF, SCF, LIF and Flt-3 ligand for several days. The cells in the culture were analysed for expansion and phenotype by flow cytometry. Although significant expansion of bone marrow cultures occurred in the presence and absence of human stroma, the results of expansion were effectively better in the presence of a stromal layer. In both situations the phenotypic analysis demonstrated a great expansion of CD 34(+)38(-) cells. The differentiative potential of bone marrow CD 34(+) cells co-cultured with human stroma was primarily shifted towards the myeloid lineage with the presence of CD 15 and CD 33.

Journal Article↗

Vena cava thrombosis associated with nephrotic syndrome in the puerperal gestational cycle.

CONTEXT: The puerperal gestational cycle is accompanied by a state of physiological hypercoagulability. Thromboembolic phenomena may occur at this time. OBJECTIVE: To report on a clinic case involving a patient that presented a family history of thromboembolism and developed deep vein thrombosis in a lower limb and vena cava thrombosis during the puerperal gestational cycle, displaying nephrotic syndrome as the main complication. DESIGN: Case report.

Adult↗

Oral manifestations of HIV positive children.

Oral manifestations in HIV positive children were observed in thirty-eight HIV infected children that have received care at the Special Care Dentistry Center (SCDC) of the School of Dentistry, University of Sao Paulo. Results have shown that 52.63% of the children presented at least one oral manifestation related with HIV/AIDS. Angular cheilitis occurred in 28.94%, parotid gland bilateral enlargement, pseudomembranous candidiasis and erythematous candidiasis in 18.42%, conventional gingivitis in 13.15%, herpes simplex in 5.26%, hairy leukoplakia, recurrent aphthous ulcer and condyloma acuminatum in 2.63%. Although enamel hypoplasia occurred in 23.68%, this could not be attributed specifically to HIV infection.

Acquired Immunodeficiency Syndrome↗

Endoscopic findings in chronic lymphocytic leukemia.

Retrospective studies, based on autopsy findings, indicate that infiltration of the gastrointestinal tract complicates leukemia of all types and may be present from the esophagus to the rectum. This report presents what is believed to be the first reported case of a patient with chronic lymphocytic leukemia with evidence of esophageal, gastric, duodenal bulb, and colonic involvement confirmed by mucosal biopsy at endoscopy.

Biopsy↗

Visceral larva migrans syndrome complicated by liver abscess.

We describe a case of visceral larva migrans syndrome complicated by liver abscess, pericardial effusion and ascites. To our knowledge, these findings have not been reported previously. The structural and immunological alterations caused by visceral larva migrans are thought to lead to the development of visceral abscesses.

Animals↗

Antigen heterogeneity among Mycoplasma mycoides subsp. mycoides SC isolates: discrimination of major surface proteins.

The protein and antigen profiles of 60 isolates, strains and the type strain PG1 of Mycoplasma mycoides subsp. mycoides s.c. were compared by sodium dodecyl sulphate polyacrylamide gel electrophoresis and immunoblot analysis. Analysis using contagious bovine pleuropneumonia antisera and hyperimmune rabbit sera against several representative strains revealed some differences in protein profiles and variability in antigens among strains from different geographic regions. The most common antigenic bands had the molecular masses of 110, 95, 80, 69, 62, 60, 48, 44, 39 and 38 kDa. There were differences among European strains, where a larger group coming from Italy lacked the p98 antigen, thus, with one exception, distinguishing the Italian strains from Portuguese, French and Spanish strains. African, Australian and PG1 strains showed heterogenic profiles, with quantitative differences and in a few strains some antigenic bands were absent. The group constituting African, Australian and PG1 strains was characterised by the presence of 71.5/70 kDa antigens, which were not detected in European strains. Mycoplasma mycoides subsp. mycoides s.c. membrane proteins were characterised by Triton X-114 partitioning and p110, p98, p95, p62/60 and p48 were identified as immunogenic antigens. The simultaneous presence of these five antigens was common to all the sera examined and, therefore, indicates the diagnostic potential of immunoblotting. Most immunodominant antigens are surface-exposed proteins as determined by the trypsin treatment.

Africa↗

Humoral and bronchial immune responses in cattle experimentally infected with Mycoplasma mycoides subsp. mycoides small colony type.

The course of immune reactions of the manifold antigens of Mycoplasma mycoides subsp. mycoides small colony type (SC) was analysed in serum and bronchial lavage of cattle experimentally infected with the African strain Afadé and the European strain L2 using Western-blots and complement fixation. Western-blot analysis of total antigens of both strains with sera from animals infected with the homologous and heterologous strain revealed the common dominant immunogenic antigens with the molecular masses of 110, 95, 85, 80, 72, 62, 48 and 39 kDa. The sequential sampling of the blood and bronchial lavages before and after contact infections allowed us to identify the antigens of 85, 80, 72, 48 and 39 kDa as particularly early immunogens. The IgA Western blots of the bronchial lavages showed distinct, early and persistent reactions to the 110, 85, 80, 72, 48 and 45 kDa proteins. These proteins were the predominant lipoproteins as determined by [14C]palmitic acid labelling. Only relatively weak reactions of the bronchial lavages were detected with IgG. In general immune responses were significantly stronger in the animals infected with the African strain Afadé, which gave positive results two weeks after contact infection. In contrast, the animals infected with the European strain L2 induced much lower reactions with a delay of three months after contact infection. In one animal strain L2 caused no sero-conversion and no infection. The results indicate a difference in virulence between the African strain Afadé and the European strain L2.

Africa↗

Schistosoma mansoni: permanence of modulation of the granulomatous inflammatory response in mice cured in the chronic phase.

Persistence of down regulation of granuloma size was studied in mice chronically infected with Schistosoma mansoni and cured by chemotherapy. The animals were reinfected at 20-, 50-, 110-, and 140-day intervals after treatment, and sacrificed 60 days post-infection. Reinfected animals were able to modulate the granulomatous inflammatory response, thus preventing a new acute phase. These findings may contribute to the explanation for the decrease of morbidity from human schistosomiasis seen in endemic areas following mass treatment.

Animals↗

[Anomalous venous drainage of the left lung. Clinical and surgical findings and diagnostic difficulties].

PURPOSE: To analyze clinical and surgical aspects of patients with anomalous left pulmonary venous drainage (ALPVD). METHODS: Seven patients, 3 males, with ages ranging from 18 months to 29 years were retrospectively studied, by analyzing the symptoms, electrocardiograms, chest X-ray, echocardiograms, angiography and surgical technique. RESULTS: All patients, but one, were symptomatic being the effort dyspnea the most prevalent symptom. Electrocardiogram showed incomplete right bundle branch block in all but one case. Chest X-ray showed prominent pulmonic vessels (6 patients), different degrees of cardiomegaly (6) and a left superior vena cava like image (3). Echocardiography correctly depicted the anomaly in 4 cases. The ALPVD was lobar in 4 cases and total in 3. In 3 patients there was pulmonary hypertension and in one venous drainage obstruction (8mmHg gradient). Six patients were operated on, 3 through a sternotomy approach with cardiopulmonary bypass and other 3 through a left thoracotomy without cardiopulmonary bypass. CONCLUSION: ALPVD has varying clinical repercussion and its clinical picture resembles atrial septal defect. Some cases may present diagnostic difficulties and echocardiograms may result in false negative findings. Cardiac catheterization is important to obtain detailed anatomic diagnosis, to evaluate the degree of pulmonary hypertension and to rule out venous obstruction. Left thoracotomy without extracorporeal circulation is indicated in ALPVD without associated defects.

Adolescent↗

[Emergency valvuloplasty with a balloon catheter of a tricuspid bioprosthesis in Ebstein's anomaly].

A case of severe stenosis of a tricuspid bioprosthesis was successfully dilated in a 13 year old young male with Ebstein's anomaly. The patient had congestive heart failure and developed cardiogenic shock; angiography revealed absence of emptying of the right atrium. Multiple size balloons (#4 to 23) were sequentially introduced with successful bioprosthesis dilation and shock resolution. Tricuspid bioprosthesis can be dilated even in critical conditions and, although a palliative procedure, balloon valvuloplasty can be a lifesaving procedure in patients with cardiogenic shock.

Adolescent↗

[Late development of congestive heart failure in interventricular communication caused by penetrating wound, with pulmonary hypertension resolution after surgical correction].

Male, 33 years-old, with onset of heart failure and edema; he used to be completely asymptomatic but mentioned he underwent previously a pleural drainage, after a hemothorax provoked by a stab wound. His physical examination confirmed he was in heart failure and showed a harsh holosystolic murmur between mitral and tricuspid areas. Cardiac catheterization demonstrated a large apical ventricular septal defect (VSD) and systemic pulmonary arterial pressures. With oxygen there was an increase in the left to right shunt and normal pulmonary vascular resistance. The clinical diagnosis was that of a traumatic VSD provoking pulmonary hypertension although a congenital etiology could not be completely ruled out. At surgery there was a sharp cut at the pericardium and an apical epicardial lesion; the VSD was patch sutured and the patient did well with control of his heart failure. A control hemodynamic study performed within the first postoperative month showed no residual shunt and complete normalization of the pulmonary pressures and resistance.

Adult↗

Evaluation of left ventricular function after acute myocardial infarction. Two-dimensional echocardiography versus radionuclide angiography. Study of 50 patients.

Two-dimensional echocardiography and gated blood radionuclide angiography was performed in 50 patients (mean age 51.3 years; 48 men and 2 women) after acute myocardial infarction, before discharge from the hospital. The aim of this study was to compare the wall motion score, determined by two-dimensional echocardiography (2DE), with the ejection fraction obtained by radionuclide angiography (RNA). The correlation between the results obtained by 2DE and RNA was good (r = 0.75; p less than 0.0001). We conclude that 2DE is a powerful diagnostic tool for the evaluation of left ventricular function.

Adult↗

Homogenous and heterogenous bone implants preserved by formaldehyde: a histologic study.

Small bone sticks from a rat and a dog, fixed in formaldehyde from one to several weeks, were used as homografts and heterografts in defects created in the mandibles of rats. The animals were killed 30, 60, 90, and 150 days after the graft implantation procedure. Histologic study showed that although the homografts induced a distinct osteogenic activity and were incorporated by the host in less than 90 days, the heterografts behaved as foreign bodies and became encapsulated by connective tissue and remained unresorbed up to 150 days. Therefore, the clinical applicability of formaldehyde-fixed homografts should be considered.

Animals↗