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Biomedical subjects

G Zamboni

Publications and source records attributed to G Zamboni.

At least 163 records · Page 9Linked to original sources
PubMed1987

Kinetic parameters of tyrosine hydroxylase in the rat's preoptic region during sleep deprivation and recovery induced by ambient temperature.

The role of catecholaminergic mechanisms in determining the changes in the rat's preoptic cyclic adenosine monophosphate (cAMP) concentration during sleep deprivation and recovery induced by ambient temperature was investigated in the present study. To this end, the activity of tyrosine hydroxylase, the rate-limiting enzyme in catecholamine biosynthesis, was measured in the preoptic region of rats maintained in: (a) control (22 degrees C for 52 h), (b) deprivation (-10 degrees C for 52 h), and (c) recovery (22 degrees C for 4 h after 48 h at -10 degrees C) conditions. The enzyme followed a Michaelis-Menten kinetic. The analysis of substrate-related kinetic parameters (Km and Vmax) did not show any clear-cut difference between experimental conditions, which, as already known, induce both sleep deprivation and recovery in relation to significant cAMP changes.

Animals↗
PubMed1986

Parathyroid hormone, calcitonin and vitamin D metabolites in beta-thalassaemia major.

Serum calcium (Ca), phosphorus (P), alkaline phosphatase (Al-P), parathyroid hormone (PTH), calcitonin (CT), 25-hydroxyvitamin D3 (25OHD3), 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) levels and urinary excretion of Ca, P, hydroxyproline (OH-P) and cyclic AMP (cAMP) were determined in summer and in winter in 13 thalassaemic children (7 aged 3-5 years-group 1-; and 6 aged 10-13 years-group 2-), who had never taken vitamin D supplements or therapy, and in two groups of 14 controls of the same age. In thalassaemics of group 1 only serum Al-P levels and OH-P urinary excretion were higher than in controls (P less than 0.01). In thalassaemics of group 2 Ca (P less than 0.05), P (P less than 0.05), PTH (P less than 0.001), CT (P less than 0.001), 25OHD3 (P less than 0.05), 1,25(OH)2D3 (P less than 0.001) levels and cAMP urinary excretion (P less than 0.001) were lower, whereas Al-P (P less than 0.001) and CT (P less than 0.001) levels and urinary excretion of P (P less than 0.05) and of OH-P (P less than 0.001) were higher than in controls, both in summer and in winter. Advancing age induces in thalassaemic patients a decrease in PTH secretion and a consequent deficit in synthesis of 1,25(OH)2D3 that may explain some aspects of bone changes, which CT hypersecretion may tend to counteract.

Adolescent↗
PubMed1985

A distinctive cutaneous malignant neoplasm expressing the Langerhans cell phenotype. Synchronous occurrence with B-chronic lymphocytic leukemia.

The authors describe a 63-year-old woman who developed a histologically distinctive malignant cutaneous neoplasm composed of large pleomorphic cells with abundant cytoplasm and multilobate, often clefted nuclei that occasionally contained small nucleoli. This neoplastic cell population metastasized to a regional lymph node already involved by a B-cell derived chronic lymphocytic leukemia expressing surface IgMk, BA-1, and OKT1. The large metastatic tumor cells lacked surface immunoglobulin, B-lymphocyte associated antigen BA-1, T-lymphocyte associated antigens OKT1 and OKT3, and the monocyte/macrophage markers lysozyme and alpha 1-antichymotrypsin. These tumor cells expressed HLA-DR antigens, adenosine triphosphatase (ATPase), OKT6, and contained S-100 protein, i.e., they expressed the phenotype peculiar to epidermal Langerhans cells. The typical clinical and histologic features of Histiocytosis X were absent. Thus, this case appears to represent a distinctive cutaneous neoplasm composed entirely of malignant cells of dendritic cell origin which, by immunophenotypic and histochemical analysis, appear to be related to epidermal Langerhans cells.

Antibodies, Monoclonal↗
PubMed1985

Gastritis cystica polyposa: a possible precancerous lesion.

Twenty polypoid lesions at gastroenterostomy stomas (the so-called gastritis cystica polyposa-GCP) were endoscopically removed from gastroenterostomy stomas of 16 male and two female patients previously operated for benign lesions. The interval from surgery ranged from 3 to 40 years (mean: 16.2 years). At light microscopy GCP showed 2 histologic patterns: a) with cystic glands limited to the mucosal layer (gastritis cystica superficialis); b) with cystic glands also spreading into the submucosa (gastritis cystica profunda). Atrophy of specific gastric glands, intestinal metaplasia and dysplastic changes also occurred. Local chronic ischemia and inflammatory reaction as a consequence of gastric surgery and suture at gastroenterostomy together with bile reflux were considered responsible for the development of GCP. The sites and the histologic features of GCP resembled those of experimental stomal polyps preceeding carcinoma in rats after partial gastrectomy. The sites of formation, the sex incidence, the interval from previous operation as well as the histologic findings suggest that GCP is a possible precancerous lesion.

Aged↗
PubMed1984

Hypothalamic temperature during desynchronized sleep.

The influence of changes in heat loss at specific heat exchangers, appraised by recording ear skin temperature (Ts), on the hypothalamic temperature (Thy) rise during desynchronized sleep (DS) was studied in unrestrained cats at different ambient temperatures (Ta). The correlations of initial and final Thy changes (delta iThy and delta fThy) with initial and final Ts changes (delta iTs and delta fTs), respectively, are statistically not significant. However, a significant negative correlation was found between delta fiThy, i.e. delta fThy-delta iThy, and delta fiTs, i.e. delta fTs-delta iTs. The latter result shows that only after its initial rise is Thy affected by changes in heat loss at specific heat exchangers during DS. Accordingly, delta fThy and delta fiThy are positively correlated with Ta. However, also delta iThy, although not affected by heat loss changes at specific heat exchangers, shows a positive correlation with Ta. On the basis of these results and of the data in the literature, it is concluded that three independent factors underlie Thy changes during DS, namely heat loss at specific heat exchangers, hypothalamic blood flow and thermogenesis.

Animals↗
PubMed1984

Hyperplastic (metaplastic) polyps of the colon. A histologic and histochemical study.

One hundred seventy-three hyperplastic polyps removed from the colon of 146 patients were carefully examined by light microscopy in order to evaluate the histologic variants. Seventy polyps were also studied histochemically in order to assess the mucin distribution. Seven polyps measured greater than 1 cm. The frequency of hyperplastic foci has been assessed in a review of 1000 colonic adenomas, 50 juvenile, 30 inflammatory, and six Peutz-Jeghers polyps. The vast majority of the hyperplastic polyps showed features similar to those of inflammatory and ischemic bowel mucosa, leading to the suggestion of an inflammatory-ischemic origin of the polyps. The frequent finding of dysplastic features within hyperplastic polyps greater than 1 cm suggests that at least the large polyps are dysplasia-prone.

Adenoma↗
PubMed1983

Enzyme-linked immunosorbent assay for leucine and methionine enkephalins.

An enzyme-linked immunosorbent assay for enkephalins was developed by coupling the peptides to a carrier molecule (bovine serum albumin) in order to allow the antibody-antigen reaction to take place in the solid phase. The assay was shown to be highly reproducible. Its sensitivity was 14 nmol/liter for leucine enkephalin and 27 nmol/liter for methionine enkephalin, which is similar to that obtained when the same antibodies were used in radioimmunoassay.

Antibodies↗
PubMed1983

Epithelial membrane antigen expression in cholangiocarcinoma. An useful immunohistochemical tool for differential diagnosis with hepatocarcinoma.

Twenty-two cases of primary hepatic tumours (16 hepatocarcinoma and 6 cholangiocarcinoma) have been studied by immunoperoxidase technique, for the presence of Epithelial Membrane Antigen (EMA). All 6 cases of cholangiocarcinoma showed positive reaction for the presence of EMA while 14 out of 16 hepatocarcinoma were completely negative. In two cases of hepatocarcinoma focal positive cells were present. The results obtained suggest that EMA could be of valuable use, in surgical pathology, for discriminating hepatocarcinoma from cholangiocarcinoma.

Adenoma, Bile Duct↗
PubMed1983

Squamous papillomas of the esophagus.

Fifteen cases of squamous papilloma of the esophagus were found in 20,000 upper gastrointestinal endoscopies. Squamous papillomas are usually incidental findings; symptoms are related to associated esophageal or gastrointestinal lesions. Chronic irritation from gastric acid reflux may play an etiological role.

Adult↗
PubMed1983

Mucin secretion and morphological changes of the mucosa in non-neoplastic diseases of the colon.

Changes in mucin secretion and increase in height of the colonic mucosa adjacent to colorectal carcinoma (transitional mucosa) have been considered pre-malignant. In this study similar changes (both morphological and histochemical) have been found in some cases of ulcerative colitis and ischaemic colitis, as well as in juvenile, inflammatory and hyperplastic (metaplastic) polyps. 'Transitional' patterns of mucin secretion also occur in some other cases of ulcerative colitis, colostomies and Crohn's disease of the colon in which the mucosa has a normal height, suggesting the changes in mucin secretion are independent of mucosal morphology. In all these pathological conditions, hyperplastic (metaplastic) mucosa also coexisted. These findings seem to suggest that: (1) 'transitional' changes more likely represent a secondary regenerative phenomenon rather than a premalignant one; (2) the pattern of mucin secretion is not selective enough to serve as a premalignant marker; therefore is not a valid prognostic indicator in colonic biopsies; (3) hyperplastic (metaplastic) changes might derive from 'transitional' mucosa as a result of a more mature phase of this exaggerated regenerative phenomenon. However, in some patients longstanding 'transitional' mucosa may lead to dysplasia under the influence of environmental and genetic factors.

Biopsy↗
PubMed1983

Juvenile and inflammatory polyps of the colon--a histological and histochemical study.

A light microscopy and histochemical study of 24 juvenile and 27 inflammatory polyps showed that both may derive from inflammatory processes. Granulation tissue, secondary to spontaneous local inflammation or due to surgical procedures may subsequently be covered by regenerating epithelium which lines haemorrhagic cavities and mucus lakes to form irregular, elongated and cystic glands, which are characteristic of juvenile polyps. Both juvenile and inflammatory polyps showed cystic, metaplastic and 'transitional-type' glands. The mucin distribution was identical in both types of polyps. All these findings suggest a common origin of the polyps. The presence of 'transitional-type' glands seems to confirm these as a secondary regenerative phenomenon rather than pre-neoplastic, although dysplastic changes in juvenile polyps have been described. It is suggested that both the juvenile and inflammatory polyps may undergo dysplasia only in genetically predisposed subjects. However, this event seems to be very rare.

Adolescent↗
PubMed1982

cAMP concentration in the rat's preoptic region and cerebral cortex during sleep deprivation and recovery induced by ambient temperature.

cAMP concentrations in the preoptic region and cerebral cortex were studied in rats during exposure to low ambient temperature (-10 degrees C) and after return to control ambient temperature (22 degrees C). Significant changes in cAMP concentration were found only in the preoptic region. On prolonged exposure to low ambient temperature the nucleotide concentration decreased and the circadian rhythm, observed in control conditions, disappeared. Return to control ambient temperature after exposure to low ambient temperature induced a steep increase and a long-lasting plateau in cAMP concentration. The results are discussed in terms of interaction between thermoregulatory and sleep-wakefulness processes.

Animals↗
PubMed1982

Transitional polyps of the colon.

Fourteen polps with the gross appearance of small hyperplastic (metaplastic) polyps, not exceeding five mm in diameter, were removed from the rectum and the sigmoid colon of patients during colonscopy, and from surgical specimens. At light microscopy they were seen to be composed of apparently normal mucosa. In most cases some hyperplastic (metaplastic) and adenomatous polyps were also present. HID-AB stain revealed the polyps to be composed of "transitional" mucosa containing almost exclusively sialomucins, in contrast to normal mucosa, in which sulphomucins predominate. It is suggested that these "transitional" polyps may represent a reservoir of hyperplastic (metaplastic) and adenomatous polps, the different fate depending on different environmental situations.

Colonic Neoplasms↗