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Biomedical subjects

R Buffa

Publications and source records attributed to R Buffa.

104 records · Page 6Linked to original sources
PubMed1976

Immunohistochemical identification of the cholecystokinin cell in the intestinal mucosa.

In indirect immunofluorescence tests, antibodies against pure porcine cholecystokinin (CCK) have detected specific CCK cells in the duodenal and jejunal mucosa of the dog and man. The CCK cells were scattered in the epithelium of the crypts, although some were in the villi. No CCK cells were found in the stomach, pancreas, terminal ileum, or colon. Some pyloric G cells also showed some reactivity with CCK antiserum, but absorption of CCK antiserum with gastrin C terminal pentapeptide prevented the staining of pyloric cells and provided specific staining of intestinal CCK cells. Anti-human gastrin I serum stained some intestinal cells too. Most of such cells did not react when gastrin antiserum was absorbed with pure CCK (a treatment that did not prevent the staining of pyloric gastrin cells); they were interpreted as cross-reacting CCK cells rather than as intestinal gastrin cells.

Animals↗
PubMed1975

Identification of the intestinal cell storing gastric inhibitory peptide.

Small intestinal mucosal samples from man, pig and dog, were subjected to sequential or correlative silver impregnation techniques, applied to immunocytochemical preparations and at the ultrastructural level. The cell reacting with anti-GIP sera was identified as the ultrastructurally classified K cell and we propose that the term GIP cell be used in place of the latter. This cell can thus be recognized by its strong reactivity with the Sevier-Munger staining procedure, provided that the equally strongly reacting EC cell is excluded by virtue of its argentaffinity with the Masson technique.

Animals↗
PubMed1975

Formaldehyde-ozone-induced fluorescence in gastrin-producing tumours.

Material from eight peptide hormone-secreting tumours, extirpated from the pancreas or from the antrum-duodenum region, was examined. Four of the patients had the clinical manifestations of the Zollinger-Ellison syndrome, two showed the features of an insulin-secreting tumour and one had a glucagonoma. Gastrin-producing cells, identified by immunohistochemistry, were found in five of the tumours. These cells displayed a varying degree of formaldehyde-ozone-induced fluorescence. This agrees with previous observations on the gastrin cell of human antral and duodenal mucosa. From model experiments, formaldehyde-ozone-induced fluorescence is thought to reflect the presence of peptides having tryptophan in the NH2-terminal position. The nature of this peptide in gastrin-producing cells is unknown.

Adult↗
PubMedDate not supplied

Variation in sexual dimorphism in relation to physical activity.

The aim of this study was to examine variations in sexual dimorphism in relation to physical activity. A sample of 542 males and females (20-30 years), born and resident in Cagliari (Sardinia, Italy), was divided into two groups: active and inactive. Twenty-five anthropometric dimensions were taken (weight, lengths, breadths, circumferences, and skinfolds). The circumferences and skinfolds were adjusted for the effects of overall body size (represented by skeletal variables). Body composition parameters--fat-free mass (FFM), fat mass (FM), and arm muscular area (AMA)--were derived from the adjusted values. The D index (Bennett, 1981; Chakraborty and Majumder, 1982) was used to assess the degree of sexual dimorphism. The difference between the D values of active and inactive individuals was analyzed with the technique of Bennett (1981). Principal components analysis (PCA) was performed on groups of homogeneous variables (circumferences and skinfolds) in order to simplify the description of the original anthropometric data. The univariate and multivariate analyses indicate a greater sex difference in the group of individuals who are regularly active. The results agree with theoretical expectations, and suggest greater stability of women to environmental pressures (i.e., physical activity).

Adult↗
PubMedDate not supplied

Variations of somatotype in elderly Sardinians.

Somatotyping is an effective technique for the study of anthropometric variations and body composition in elderly subjects, even though it has not often been used in this field. The present study was conducted on a sample of 280 healthy Sardinians (134 men and 146 women) of age 60-89 years, subdivided into three age classes (60-69 years; 70-79 years; and 80-89 years). Somatotypes were computed according to Carter and Heath (Somatotyping-Development and Applications. Cambridge, England: Cambridge University Press; 1990). The results show a dominance of the endo- and mesomorphic components in the elderly subjects, with less development of ectomorphy than in younger individuals. In a comparison with other populations, our sample shows strong development of endomorphy and especially of mesomorphy, while ectomorphy values are generally low. Age-related variations are significant in both sexes and consist in a progressive reduction of the endomorphic component, particularly in the 80-89-year class (endomorphy in the three age classes: 6.4, 6.1, and 5.3 in men; 8.1, 7.8, and 6.8 in women). The mesomorphic component is characterized by stability (age variations: 6.4, 6.4, and 5.9 in men; 6.3, 6.4, and 6.3 in women) and the ectomorphic component by a slight increase (age variations: 0.5, 0.6, and 0.8 in men; 0.4, 0.3, and 0.5 in women). Sex differences are significant and especially large for the endomorphic component, with generally higher values in women. The sexual dimorphism tends to decrease with age. The results are discussed with regard to the biology of aging, with emphasis on the potential application of somatotype to studies of the elderly population.

Age Factors↗
PubMedDate not supplied

Lymph node micrometastases in patients with adenocarcinoma of the esophagogastric junction.

Recurrences of adenocarcinoma of the esophagogastric junction are frequent even in patients who are classified as pN0 after radical resection, suggesting that occult nodal metastases may have been missed on routine histologic examination. Immunohistochemical analysis using antibodies to cytokeratin was retrospectively performed in 1301 lymph nodes from 46 patients who underwent surgical resection for adenocarcinoma of the esophagogastric junction through a laparotomy and a right thoracotomy. Compared to routinely stained sections, the total number of metastatic lymph nodes was significantly (P = 0.0001) increased when both serial sectioning and anticytokeratin immunohistochemical analysis were performed. Overall 6 (33.3%) of the 18 patients previously considered N0 were recategorized as N1 for the presence of micrometastases to lesser curvature nodes. Three of these patients had recurrent disease within the first year of follow-up. Both the probability of survival or no recurrence and the disease-free survival were significantly greater in patients in whom the ratio of invaded to removed lymph nodes was less than 0.2. Anticytokeratin analysis identified occult nodal metastases in one third of our patients with adenocarcinoma of the esophagogastric junction. This modified tumor staging and had an impact on overall and disease-free survival.

Adenocarcinoma↗
PubMedDate not supplied

Immunohistochemical and molecular analysis of bax, bcl-2 and p53 genes in laryngeal squamous cell carcinomas.

BACKGROUND: We investigated the role of apoptosis and its potential alterations in laryngeal squamous cell carcinomas (LSCCs) by evaluating bax, bcl-2 and p53 protein expression in 50 cases and by characterising the molecular status of the bax and p53 genes. MATERIAL AND METHODS: p53 and bax gene mutations were investigated by means of PCR/SSCP and direct DNA sequencing, and bax, bcl-2 and p53 protein expression by means of immunohistochemistry. RESULTS: We identified p53 gene mutations in 17/50 cases (34%); p53 expression in 26 of the 50 cases (52%); bcl-2 expression in 5/50 cases (10%); bax expression in 32/47 cases (68%). 18/33 cases with a wild type p53 gene overexpressed p53 protein: 12 cases (approximately 66%) were bax+/bcl-2-. Of the remaining cases without p53 protein expression, seven cases (approximately 47%) were bax+/bcl-2-. CONCLUSIONS: Our observations suggest that the overexpression of p53 may contribute to the repression of bcl-2 and the induction of bax expression in LSCCs. However, the fact that a number of cases not expressing p53 did not present any clear up-regulation of bax or down-regulation of bcl-2 suggests that bcl-2 and bax may be regulated by various mechanisms other than p53.

Aged↗
PubMedDate not supplied

Distinct patterns of chronic gastritis associated with carcinoid and cancer and their role in tumorigenesis.

A series of 60 gastric endocrine tumors comprised 44 body-fundus argyrophil carcinoids, of which 23 arose in a background of hypergastrinemia and type A chronic atrophic gastritis (A-CAG), mainly with histologic patterns suggestive of an autoimmune process. Only 22 percent (compared with 19 percent of 58 tumor-free A-CAG cases) of 36 carcinoids and 21 percent of 19 A-CAG carcinoids investigated had Helicobacter pylori (HP) colonization, against 50 percent of 14 CAG-associated neuroendocrine carcinomas or mixed endocrine-exocrine tumors, 84 percent of 150 cases with early gastric cancer (p < 0.001 versus carcinoids), mostly with B- or AB-type CAG, 76 percent of 97 tumor-free AB-CAG, and 95 percent of 151 tumor-free B-CAG cases. Secondary hypergastrinemia and local mechanisms activated by chronic autoimmune gastritis are among factors involved in the pathogenesis of relatively indolent CAG-associated carcinoids, whereas active HP gastritis in cooperation with environmental carcinogens may likely cause more severe epithelial transformation, leading to ordinary cancer and, possibly, to neuroendocrine carcinomas or mixed endocrine-exocrine tumors.

Autoimmune Diseases↗
PubMedDate not supplied

p53 and cyclinX D1 protein expression in carcinomas of the parotid gland.

BACKGROUND: p53 and cyclin D1 genes play a central role in the regulation of the G1 phase of the cell-cycle, and are frequently involved in head and neck tumorigenesis. MATERIALS AND METHODS: By means of immunohistochemistry, we retrospectively investigated the overexpression of cyclin D1 and p53 genes in a series of 28 parotid gland carcinomas. The immunohistochemical analysis was performed using the ABC method and the antibodies DCS6 (for cyclin D1) and CM1 (for p53). RESULTS: p53 was overexpressed in 12 (42.9%) and cyclin D1 in 6 cases (21.4%). No significant association was found between p53 or cyclin D1 expression and the evaluated clinicopathological parameters of tumor extension, clinical stage, and lymph node or distant metastases. Nevertheless, it is worth noting that all of the patients with a high expression of p53 died of their disease. CONCLUSIONS: The present data confirm the role of p53 abnormalities in the pathogenesis of salivary gland carcinoma and report, for the first time, the involvement of cyclin D1 gene in these tumors.

Adult↗