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Dive into the research topics where Alfredo José Afonso Barbosa is active.

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Featured researches published by Alfredo José Afonso Barbosa.


Scandinavian Journal of Gastroenterology | 1993

Effect of Helicobacter pylori eradication on antral gastrin- and somatostatin-immunoreactive cell density and gastrin and somatostatin concentrations

Dulciene Maria Magalhães Queiroz; Edilberto Nogueira Mendes; Gifone A. Rocha; Sílvia B. Moura; L. M. H. Resende; Alfredo José Afonso Barbosa; Luiz Gonzaga Vaz Coelho; M. C. E. Passos; Luiz de Paula Castro; Celso Affonso de Oliveira; Geraldo Lima

The density of antral gastrin (G)- and somatostatin (D)-immunoreactive cells and the contents of antral gastrin and somatostatin were investigated in endoscopic antral biopsy specimens from patients with duodenal ulcer before and after eradication of Helicobacter pylori. After H. pylori eradication both antral somatostatin concentration (p = 0.0002) and antral D-cell density (p = 0.01) increased significantly. Conversely, although the number of G-cells was unchanged, antral (p = 0.0002) and serum (p = 0.001) gastrin contents decreased significantly. The number of oxyntic D-cells did not change significantly. These results strongly suggest that the hypergastrinaemia observed in H. pylori-positive patients may be due to a deficiency in antral somatostatin, which normally inhibits the synthesis and release of gastrin.


Revista Do Instituto De Medicina Tropical De Sao Paulo | 1996

Histopathology and immunocytochemical study of type 3 and type 4 complement receptors in the liver and spleen of dogs naturally and experimentally infected with Leishmania (Leishmania) chagasi

Wagner Luiz Tafuri; Washington Luiz Tafuri; Alfredo José Afonso Barbosa; Marilene Susan Marques Michalick; Odair Genaro; João Carlos França-Silva; Wilson Mayrink; Evaldo Nascimento

The objective of this study was to compare the histopathological changes and expression of CR3 and CR4 in the liver and spleen of dogs naturally and experimentally infected with L. chagasi. The basic histopathological lesions observed mainly in naturally infected dogs were: epithelioid hepatic granulomas, hyperplasia and hypertrophy of Kupffer cells, Malpigui follicles and mononucleated cells of the red pulp of the spleen. Sections from the liver and spleen by immunocytochemistry technique showed the presence of CD11b, c/CD 18 antigens in the control and infected animals and no qualitative or quantitative differences in the liver. Nevertheless, CD18 was always increased in the spleen of naturally and experimentally infected dogs. These results indicate that there is a difference in the activation of CD18 in both experimental and natural cases of canine visceral leishmaniasis that should play an important role in the immunological response to Leishmania chagasi infection.


The Lancet | 1994

Effect of Helicobacter pylori eradication on G-cell and D-cell density in children

Dulciene Mm Queiroz; S.B. Moura; E.N. Mendes; G.A. Rocha; Alfredo José Afonso Barbosa; AsT Carvalho

Helicobacter pylori infection is associated with abnormalities in serum gastrin concentration, antral gastrin and somatostatin content, and D-cell density in adults. We have studied the effects of H pylori infection in children. We studied 13 children positive for H pylori and 7 negative children. The median antral somatostatin content was significantly lower in the positive than in the negative group (0.69 [range 0.35-0.91] vs 1.31 [0.73-1.67] ng/mg, p = 0.007). Both antral and serum gastrin concentrations were significantly higher in the positive group (30.1 [15.3-83.6] vs 14.8 [13.8-28.8] ng/mg, p = 0.008; and 89.9 [59.4-313.2] vs 29.5 [13.9-71.1] pg/mL, p = 0.006). Treatment to eradicate H pylori was successful in 11 of the 13 positive patients. With eradication antral somatostatin increased to within the normal range (by a median of 0.41 [0.21-0.86] ng/mg to 1.10 [0.81-1.55] ng/mg, p = 0.016). Serum and antral gastrin decreased (by 37.1 [5.5-265.2] pg/mL to 52.8 [21.4-267.5] ng/mg, p = 0.001; and by 8.0 [2.0-47.2] ng/mg to 22.1 [10.9-37.5] ng/mg, p = 0.001). Eradication of H pylori also significantly increased antral D-cell density (8 [5-22] to 15 [9-22] cells per mm, p = 0.031) and decreased G-cell density (138 [89-161] to 88 [33-121] cells per mm, p = 0.016). The hypergastrinaemia in children positive for H pylori may be due to a deficiency of antral somatostatin, which inhibits gastrin synthesis and release.


Journal of Pediatric Gastroenterology and Nutrition | 1991

DIFFERENCES IN DISTRIBUTION AND SEVERITY OF HELICOBACTER PYLORI GASTRITIS IN CHILDREN AND ADULTS WITH DUODENAL ULCER DISEASE

Dulciene Maria Magalhães Queiroz; Gifone A. Rocha; Edilberto Nogueira Mendes; Alfredo José Afonso Barbosa; Celso Affonso de Oliveira; Geraldo Lima

The presence of Helicobacter pylori and the gastric mucosa histology were investigated in 15 children and 15 adults with duodenal ulcer. The microorganism was isolated from antral and oxyntic mucosa in 100% of patients, both adults and children. The results of Gram stain and preformed urease test were compared with those of culture and there was no difference in sensitivity among the tests. Antral chronic gastritis was observed in all patients. However, children presented oxyntic gastritis more frequently than adults. It was also observed that the endoscopic aspects were different in the two groups of patients. The results here observed strongly support the idea that, as well as in adults, H. pylori is the causative agent of the gastritis seen in children with duodenal ulceration. On the other hand, the histological findings of oxyntic mucosa of children with duodenal ulcer were different from those of adults.


Biotechnic & Histochemistry | 1984

A Simple and Economical Modification of the Masson-Fontana Method for Staining Melanin Granules and Enterochromaffin Cells

Alfredo José Afonso Barbosa; Lúcia Porto Fonseca de Castro; Ana Margarida; M. F. Nogueira

Enterochromaffin cells from the small intestine of man, guinea pig, dog, chicken, rabbit, cat and rat were stained using the Masson-Fontana ammoniacal silver method with varying dilutions of silver nitrate solution (0.25 to 5 g per 100 ml of distilled water) and incubation temperatures (60 C and 75 C). The 0.5% solution of silver nitrate gave an argentaffin pattern similar to that of the 5% solution and had two major advantages: economically, since much less silver nitrate is used, and methodologically, since low background resulted with tissue of those species (rat, cat and rabbit) that required unusually long incubation. The staining of melanocytes was similar for all dilutions at the usual staining time (15-30 min).


Revista Do Instituto De Medicina Tropical De Sao Paulo | 1989

Estudo, ao microscópio óptico e eletrônico, do rim de caes natural e experimentalmente infectados com Leishmania (Leishmania) chagasi

Washington Luiz Tafuri; Marilena Suzan Marques Michalick; Magno Dias; Odair Genaro; Virginia Hora Rios Leite; Alfredo José Afonso Barbosa; Eduardo Alves Bambirra; Carlos Alberto da Costa; Maria Norma Melo; Wilson Mayrink

Two naturally infected dogs (male and fema lei from Teofilo Otoni (MG Brazili were maintained for 18 months in our laboratory. Two other dogs, two months old males were infected with 1 x 106 promastigotes of MHO BR 70 BH46 Leishinania (Leishmanial chagasi strain, endo venous route, and autopsied after 10 months and two years. The main findings concerning the kidney were: (1) focal or diffuse mesangial glomerulo nephritis with proliferative and enlargement of mesangial cells; (2) increase in thickness of basement membrane with electron dense deposits: (3) chronic interstitial nephritis with intense exudation of plasmocytes: (4) cloud swelling of renal tubules. The authors discuss the probable pathogenetic mechanisms.Two naturally infected dogs (male and female) from Teófilo Otoni (MG-Brazil) were maintained for 18 months in our laboratory. Two other dogs, two months old males were infected with 1 x 10(6) promastigotes of MHO/BR/70/BH46 Leishmania (Leishmania) chagasi strain, endovenous route, and autopsied after 10 months and two years. The main findings concerning the kidney were: (1) focal or diffuse mesangial glomerulonephritis with proliferative and enlargement of mesangial cells; (2) increase in thickness of basement membrane with electron-dense deposits; (3) chronic interstitial nephritis with intense exudation of plasmocytes; (4) cloud swelling of renal tubules. The authors discuss the probable pathogenetic mechanisms.


European Journal of Endocrinology | 2011

Density of ghrelin-producing cells is higher in the gastric mucosa of morbidly obese patients

Fabiana Alves Nunes Maksud; Jairo Silva Alves; Marco Túlio Costa Diniz; Alfredo José Afonso Barbosa

BACKGROUND Ghrelin is a peptide mainly secreted by gastric mucosa and has been implicated in the regulation of eating behavior and weight balance. Obesity and Helicobacter pylori infection are associated with changes in plasma ghrelin levels. OBJECTIVE This study was designed to evaluate the density of ghrelin-producing cells in the gastric mucosa of morbidly obese and dyspeptic non-obese patients, with and without H. pylori infection. METHODS Gastric biopsies of the antral and oxyntic mucosa were obtained from 50 morbidly obese patients (BMI >40, 21 with metabolic syndrome (MS)), 17 dyspeptic overweight subjects (25<BMI<30), and 33 lean individuals (BMI<25) and processed for histology and immunohistochemistry. RESULTS Ghrelin-immunoreactive cell densities in the oxyntic mucosa were similar in morbidly obese patients with MS and in overweight and lean patients, whereas morbidly obese patients without MS presented higher ghrelin-immunoreactive cell density. The number of ghrelin cells in the oxyntic mucosa was significantly lower in obese and non-obese H. pylori-infected subjects. Ghrelin-immunoreactive cells, although sparse in the antral mucosa, were found more frequently in obese patients and their numbers did not seem to be affected by H. pylori infection. CONCLUSIONS The higher expression of ghrelin-immunoreactive cells in the oxyntic mucosa of morbidly obese patients compared with non-obese subjects or with morbidly obese subjects with MS and the finding of a higher number of small foci of ghrelin cells in the antral mucosa of obese patients may indicate an adaptive mechanism or an individual factor to be considered in the pathogenesis of obesity.


Arquivos De Gastroenterologia | 2007

The presence of Helicobacter Pylori in postmenopausal women is not a factor to the decrease of bone mineral density

Adriana Maria Kakehasi; Cláudia M. C. Mendes; Luiz Gonzaga Vaz Coelho; Luiz de Paula Castro; Alfredo José Afonso Barbosa

BACKGROUND Osteoporosis affects approximately 30% of postmenopausal women. Gastrectomy, pernicious anemia, and more recently Helicobacter pylori infection, have all been implicated in the pathogenesis of osteoporosis. A reduced parietal cell mass is a common feature in these conditions. AIM To study a possible relationship between chronic gastritis, parietal cell density of the oxyntic mucosa and bone mineral density in postmenopausal women, as chronic gastritis, Helicobacter pylori infection and osteoporosis are frequently observed in the elderly. METHODS Fifty postmenopausal women (61.7 +/- 7 years) were submitted to gastroduodenal endoscopy and bone densitometry by dual energy X-ray absorptiometry. Glandular atrophy was evaluated objectively by the determination of parietal cell density. Helicobacter pylori infection was evaluated by histology, urease test and breath test with 13C. RESULTS Thirty-two patients (64%) presented chronic multifocal gastritis, and 20 of them (40%) showed signs of gastric mucosa atrophy. Lumbar spine osteoporosis was found in 18 patients (36%). The parietal cell density in patients with and without osteoporosis was 948 +/- 188 and 804 +/- 203 cells/mm(2), respectively. Ten osteoporotic patients (55%) and 24 non-osteoporotic patients (75%) were infected by Helicobacter pylori. CONCLUSION Postmenopausal women with osteoporosis presented a well-preserved parietal cell density in comparison with their counterparts without osteoporosis. Helicobacter pylori infection was not different between the two groups. We concluded that neither atrophic chronic gastritis nor Helicobacter pylori seem to be a reliable risk factor to osteoporosis in postmenopausal women.


Revista Do Instituto De Medicina Tropical De Sao Paulo | 1986

Estudo comparativo entre o método convencional e o método da peroxidase anti-peroxidase na pesquisa do parasitismo tissular na cardiopatia chagásica crônica

Alfredo José Afonso Barbosa; H. Gobbi; B. T. Lino; E. Lages-Silva; L. E. Ramirez; V. P. A. Teixeira; H. O. Almeida

Na maioria dos chagasicos cronicos o Trypanosoma cruzi nao e detectado no tecido ou apresenta se com extrema raridade, mesmo quando e pesquisado exaustivamente. Sendo os metodos utilizados, ate entao, inespecificos para a demonstracao do T. cruzi, propos-se no presente trabalho proceder ao estudo comparativo entre o metodo convencional (HE) e o metodo imunocitoquimico pela peroxidase anti-peroxidase (PAP), na avaliacao quantitativa do parasitismo. Selecionaram-se 3 casos de cardiopatia chagasica cronica e, de um mesmo fragmento de cada caso, obtiveram se cortes que foram corados pelo H.E. (media de 100 cortes por caso) e, consecutivamente, outros que foram corados pelo PAP (media de 70 cortes por caso). O caso n.° 1 foi autopsiado em 1952 e apresentava parasitismo frequente. Nos demais, o exame rotineiro foi negativo. Obtiveram-se os seguintes resultados expressos em n.° de ninhos/100 cortes, respectivamente, corados pelo H.E. e pelo P.A.P. (HE/PAP). Caso n.° 1 - 80/171; caso n.° 2 = 5/116 e caso n.° 3 = 1/2. Os resultados mostram que o metodo imunocitoquimico empregado, alem de facilitar o diagnostico do parasitismo, demonstra tambem pequenos ninhos de amastigotas que dificilmente seriam diagnosticados pelos metodos convencionais; alem disso mostrou-se util mesmo em tecido incluidos em parafina ha longo tempo.


Revista Da Sociedade Brasileira De Medicina Tropical | 2006

Schistosomiasis mansoni of the prostate

José Roberto Lambertucci; Izabela Voieta; Alfredo José Afonso Barbosa

A 56-year-old man came to hospital for a routine checkup. His medical history and physical examination wereunremarkable. Laboratory evaluation was normal, except for aserum prostate specific antigen (PSA) of 6.5ng/mL (referencevalues: 0-3.5ng/mL). Digital rectal examination revealed anenlarged well-delimitated prostate. Transrectal ultrasonographywas normal. A biopsy retrieved 9 fragments of prostate tissueand histology showed no alterations. He was followed at theoutpatient clinic for another 3 months and a second PSA showedincreasing levels (7.2ng/mL). A second transrectal biopsy showedno malignant infiltration of the prostate, but eggs of S. mansonisurrounded by characteristic granulomata were described(Figure A shows a granuloma surrounding an egg shell with aremnant miracidium and Figure B shows normal prostate tissue).The patient was treated with praziquantel (60mg/kg, body weight,divided in two equal doses given at 4 hour intervals) and is beingfollowed at the outpatient clinic. A diagnosis of adenocarcinomaof the prostate has not been discarded.O paciente, de 56 anos, veio ao hospital para exame de rotina.A sua historia medica e o exame fisico nao revelaram alteracoesde importância. Os exames de laboratorio mostraram-se normais,exceto pela elevacao do nivel do antigeno prostatico especifico nosoro (PSA = 6,5ng/mL – valores de referencia = 0-3,5 ng/mL).O toque retal revelou aumento da prostata e contornos bemdelimitados. A ultra-sonografia transretal mostrou uma prostatade aspecto normal. Nao houve alteracoes histologicas em novefragmentos de tecido prostatico obtido por biopsia. O pacientefoi acompanhado em ambulatorio por tres meses e o segundoPSA aumentou para 7,2ng/mL. A segunda biopsia da prostatanao revelou sinais de malignidade, mas evidenciou ovos de S.mansoni dentro de granulomas bem formados (Figura A:granuloma ao redor de casca de ovo contendo restos de ummiracidio; Figura B: tecido prostatico normal). O paciente foitratado com praziquantel na dose de 60mg/kg de peso, divididoem duas tomadas com intervalo de quatro horas. Ele continuasendo acompanhado em ambulatorio. O diagnostico deadenocarcinoma da prostata nao foi descartado.

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Andy Petroianu

Universidade Federal de Minas Gerais

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Adagmar Andriolo

Federal University of São Paulo

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Edilberto Nogueira Mendes

Universidade Federal de Minas Gerais

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Gifone A. Rocha

Universidade Federal de Minas Gerais

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José Roberto Lambertucci

Universidade Federal de Minas Gerais

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Carlos Brites

Federal University of Bahia

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Domingo Marcolino Braile

Faculdade de Medicina de São José do Rio Preto

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Edson Marchiori

Federal University of Rio de Janeiro

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Geraldo Pereira Jotz

Universidade Federal do Rio Grande do Sul

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