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Biomedical subjects

R Naccarato

Publications and source records attributed to R Naccarato.

At least 127 records · Page 7Linked to original sources

Longitudinal study on osteodystrophy in primary biliary cirrhosis (PBC) and a pilot study on calcitonin treatment.

The aims of this study were to evaluate bone metabolism in primary biliary cirrhosis (PBC) and the effect of ADFR (activate, depress, free, repeat) therapy with vitamin D, calcium and calcitonin in preventing bone resorption. Sixty-nine female subjects entered the study: 38 PBC (AMA + ve) patients, 11 AMA-negative chronic liver disease patients and 20 age-matched healthy controls. Bone metabolism was evaluated by biochemical parameters and dual-photon absorptiometry of the lumbar spine at time 0, 6 and 18 months. Both PBC and chronic liver disease (CLD) patients showed low levels of serum 25-hydroxyvitamin D, osteocalcin and bone mineral content expressed as AAD (average area density) compared to healthy controls. Serum parathyroid hormone in PBC patients was at the lower limit of the normal range and was significantly lower than patients with chronic liver disease. At a 6-month interval, AAD significantly decreased in PBC patients (p less than 0.005). At the 6-month period PBC patients were allocated into two groups according to a cut-off AAD of 0.800 g/cm2: group A (no treatment, AAD greater than 0.800, n = 11), group B (treatment, AAD less than 0.800, n = 13). The latter group received a 4-week course with oral calcium carbonate (1500 mg daily) + oral 1,25-dihydroxyvitamin D (0.5 micrograms twice a day for 5 days) + carbocalcitonin (40 U MRC) i.m. thrice a week. The treatment was repeated with the same protocol at 2-month intervals for 12 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Inhibition of gastric acid secretion reduces zinc absorption in man.

Numerous factors seem to affect zinc absorption. Gastric acid secretion has been demonstrated to facilitate iron absorption. The zinc tolerance test (ZTT with ZnSO4 220 mg p.o.) was performed in 11 healthy volunteers to study the effects of administering the acid secretion inhibitor cimetidine (1 g/day p.o. for 3 days) and to evaluate the influence of HCl gastric secretion on zinc absorption in physiological conditions. Zinc absorption was reduced after cimetidine administration (p less than 0.005), suggesting that gastric pH influences zinc absorption. To rule out any direct effect of the drug on zinc absorption in five other healthy adults we further evaluated zinc absorption by using a different H2 antagonist (ranitidine 300 mg/day for 3 days and 300 mg before the test). Cimetidine was also tested in these subjects at half the dosage administered to the first group of subjects. Gastric acidity was monitored at 60-min intervals throughout the test via a nasogastric tube. The areas under the plasma concentration curves for zinc were significantly reduced after ranitidine (p less than 0.01), but not after cimetidine administration. Gastric acid was also reduced after ranitidine, but not after cimetidine (500 mg) administration, suggesting that gastric acid secretion plays a role in the regulation of zinc absorption in man.

Adult↗

Direct involvement of human gastric mucosa in the activation of alimentary pro-carcinogens.

Exposure to N-nitroso-compounds and aromatic amines, xenobiotics which require an activation in order to exert their genotoxic potential, is causally associated with gastric cancer. We evaluated the capacity of microsome-containing fractions from human gastric mucosa to activate two model carcinogenic compounds. A 9,000 x g supernatant (S9) was obtained from gastric mucosal specimens and, for comparison, from human liver and aroclor-induced and non induced rat liver. The capacity of the S9 to activate N-nitrosopyrrolidine (NPY) and 2-aminofluorene (2AF) to mutagenic metabolites was tested in the Ames/Salmonella reversion assay, while dimethylnitrosamine (DMN) and aminopyrine (AP) demethylation activities were spectrophotometrically evaluated by using an enzymatic assay of the amount of formaldehyde released following the enzymatic demethylation of the corresponding substrates. Results indicate that human gastric S9 fractions may activate 2AF to a genotoxic derivative and are characterized by DMN and AP demethylase activities higher (p < 0.05) than those of human liver, when expressed in mg/protein (p < 0.05). Although the parameters evaluated can only be considered as a partial measure of the general activating capacity toward dietary and environmental procarcinogens, these results suggest that human gastric mucosa may be directly involved in the metabolic activation of these compounds to mutagenic/carcinogenic species.

Aminopyrine N-Demethylase↗

Hepatic changes and serum ferritin in pancreatic cancer and other gastrointestinal diseases: the role of cholestasis.

Serum ferritin, prealbumin, pseudocholinesterase, alpha-1-antitrypsin and caeruloplasmin were determined in control subjects and patients with pancreatic cancer, chronic pancreatitis or extra-pancreatic disease mainly of gastrointestinal origin, in order to investigate the different hepatic changes which influence serum ferritin in chronic pancreatic and other digestive diseases. Increased circulating ferritin was found in pancreatic cancer and extra-pancreatic disease when compared to controls. Correlations were detected between ferritin and the other proteins investigated and between ferritin and total bilirubin, alkaline phosphatase and alanine aminotransferase. Multiple regression analysis demonstrated that cholestasis accounts for 45% of circulating ferritin, the acute-phase response accounted for 18% and decreased liver function accounted for 11%. We conclude that the increase in serum ferritin in chronic pancreatic and other gastrointestinal diseases largely depends on liver changes, with cholestasis probably playing a primary role.

Adult↗

A high degree of exposure to hepatitis A virus infection in urban children in Cameroon.

In January 1989, the prevalence of antibodies to hepatitis A virus (anti-HAV) was determined by ELISA in 702 apparently healthy children 5-14 years old in Kumba City, Cameroon. Children were recruited from those attending six different primary schools, representative of the socio-demographic characteristics of the inhabitants, using a systematic random sampling. The overall IgG anti-HAV prevalence was 96.9%, reaching 100% by the age of 11 years. In primary school beginners the prevalence was very high, 94.0%, contrary to what has been observed in developed countries. The anti-HAV prevalence was not associated with family size, but was related to parent's occupation, children from the lower class having a 5.9 fold risk (C.I. = 1.9-18.3) of past exposure to HAV. These results suggest a persistently high prevalence of anti-HAV in children despite improving hygienic conditions. The spread of HAV in this population may be the result of domestic water and/or food contamination.

Adolescent↗

Eosinophilic gastroenteritis: report of two atypical cases.

Eosinophilic Gastroenteritis (EG) is a poorly understood disorder defined by eosinophilic infiltration of the bowel wall, eosinophilia and gastrointestinal symptoms. The disease's aetiology, course and treatment are not well known. We report two atypical cases of EG: one involving the mucosal layer and another involving the serosal and muscularis layer. The first shows how EG may present with a long history of episodes of intestinal obstruction and malabsorption and how the disease could take a severe course and may be unresponsive to treatment. The second case shows EG presenting as acute abdomen and which subsequently became asymptomatic without therapy, regardless of the fact that peripheral eosinophilia remained present. This case raises the problem of how to treat an asymptomatic patient, what parameters should be considered in order to assess the progress of the disease and the indications for treatment.

Adult↗

Sex hormone changes in post-menopausal women with primary biliary cirrhosis (PBC) and with cryptogenic chronic liver disease.

Sex hormones and sex hormone binding globulin (SHBG) have been studied in 32 female post-menopausal patients (16 with Primary Biliary Cirrhosis (PBC) and 16 with cryptogenic chronic liver disease (CLD). Dehydroepiandrosterone-sulfate (DHEA-S) serum levels were significantly higher in PBC compared to CLD subjects (p less than 0.005). In PBC DHEA-S concentration was higher in precirrhotic than in cirrhotic patients (p less than 0.02). SHBG was raised in both PBC and CLD patients but higher in CLD compared to PBC subjects (p less than 0.002). PBC reveals a sex hormone pattern similar to post-menopausal subjects with breast cancer. These results suggest that sex hormone alteration is present in females with different types of liver disease, but the metabolic pattern is not due to liver disease per se.

Aged↗

Primary biliary cirrhosis in the elderly.

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease with onset about menopause. To investigate its clinical features and the natural history in relation to age, we examined 86 consecutive patients with PBC (81 F, 5 M); 70 were less than 65 years (mean age 48 years) and 16 greater than 65 years (mean age 69 years). All patients were followed-up for 6 months-16 years (mean 4 years). Histological stage at presentation was comparable in the two groups, but among aged PBC subjects there was a significantly higher prevalence of asymptomatic patients (56% vs 24%, p less than 0.001). No significant differences were observed in the biochemical indices and immunological abnormalities. Survival curves showed no significant differences in PBC according to the age. Mortality was observed only in the group less than 65 years (15/70, 21.4%). In conclusion, the large proportion of asymptomatic subjects in the elderly PBC patients accounts for the similar survival in the two groups of patients.

Adult↗

[Ulcer and hepatic cirrhosis. Epidemiologic and clinical correlations].

Peptic ulcer has been reported with increased frequency in patients with liver cirrhosis, its prevalence ranging form 5% to 20%. The aim of the present study is twofold: 1) to define the frequency of peptic ulcer in chronic liver disease in a large sample of cirrhotic patients, 2) to investigate the epidemiological and clinical features of a group of subjects affected by both peptic ulcer and liver cirrhosis. Two years of admission have been retrospectively investigated to define the frequency of peptic ulcer in chronic liver disease. In 237 subjects affected by both cirrhosis and peptic ulcer, epidemiological and clinical data were collected. Peptic ulcer was present in 16% of cirrhotic patients. There were no differences between ulcer subjects who drank and those did not. A linear positive correlation between smoking habit and frequency of ulcer disease has been found in the words. A positive history for peptic ulcer was described in a little subgroup of the studied sample, suggesting a low importance of the genetic factor in the pathophysiological pattern of ulcer disease in chronic hepatitis.

Adult↗

[Basal and postprandial blood gastrin in peptic ulcer. The physiopathological aspects in relation to different sites of the lesion].

A different pathophysiological mechanism is widely accepted for gastric and duodenal ulcer. In particular, the exact role of gastrin in the determinism of non hormono-dependent peptic ulcer disease is not completely clarified. Therefore, the aim of present study was to analyse fasting and post-prandial serum gastrin levels in 99 duodenal ulcer patients, 17 gastric ulcer patients and 11 subjects presenting an association of gastric and duodenal ulcer. The possible correlation between post-prandial gastrin concentrations and basal and maximal acid output in the 3 fasting serum gastrin levels appear not different among the 3 classes of patients, while post-prandial gastrin concentrations are statistically higher at 15 minutes in duodenal ulcer patients and in subjects with the association of gastric and duodenal ulcer as compared to gastric ulcer patients. Mean fasting and stimulated gastrin levels are higher in gastric ulcer females than in males during the entire test and with statistically difference at 30 minutes. The concentrations of the hormone are not different in males of the 3 groups of patients at basal time, while are statistically lower at 15 and 30 minutes in gastric ulcer males compared to the males with duodenal ulcer and the association of the localization. Finally, positive correlation has been observed between BAO and MAO and post-prandial gastric concentrations in the 3 groups of patients, while there is an inverse correlation between the previous parameters as regards sex, both in gastric and duodenal ulcer.

Adult↗

[Value and limitations of neoplasm markers in the diagnosis of pancreatic carcinoma].

In the last decades several markers of pancreatic neoplasia have been proposed to obtain a diagnosis as earlier as possible. Prerequisites of a good tumor marker are high sensitivity and specificity. Among the various substances, serum determination of pancreatic enzymes has been found of no utility in early diagnosis of pancreatic cancer, due to its lack in sensitivity and specificity. Similar results with ribonuclease and deoxyribonuclease. Oncofetal antigens (CEA and POA) have been initially considered promising indices; however, further studies showed their limits. In particular CEA is greatly influenced by the presence of hepatic metastases; therefore, serum levels are detectable only in advanced stages. TPA is characterized by a high sensitivity, but lacks in specificity and its use is now avoided. A real progress in the field of tumor markers has been made in the last years with the monoclonal antibody technique: among them CA 19-9 showed a good sensitivity and a satisfactory specificity as regards the diagnosis of pancreatic cancer. However, it cannot be considered as absolute aid, since it is influenced by several factors, as tumor spread, jaundice and liver dysfunction.

Antigens, Neoplasm↗

Failure of secretin to exert an ameliorative effect on acute reflux pancreatitis in the rat.

This study was undertaken to evaluate the possible ameliorative effect of secretin on acute reflux pancreatitis in the rat. Thirty days after the performance of a gastrojejunal anstomosis, in all rats (36 Sprague-Dawley, mean weight 250 g) acute pancreatitis was induced by creating a closed duodenal loop for 12 h. In the subsequent 12 h group A (14 rats) received continuous intra-arterial infusion of secretin (5 CU/kg/h); group B (22 rats) received equal volumes of saline solution. Serum amylase and pancreatic histology were evaluated. In group B a mild form of pancreatitis was observed, since the mean values of haemorrhage, necrosis and steatonecrosis, indices of severe disease, were found to be low. Group A presented similar results. No difference was documented between the two groups for both the histological findings and serum amylase. We can conclude that despite the reported protective and ameliorative effects of secretin in cerulein-induced acute pancreatitis in the rat, our data do not support a similar action of secretin in the closed duodenal loop model.

Acute Disease↗

Serum phospholipase A2 activity in chronic pancreatic diseases.

This study was performed to investigate the phospholipase A2 (PLA2) serum activity in patients with chronic pancreatic disease. PLA2, elastase-1, total, and pancreatic isoamylase were evaluated in 40 control subjects, 28 patients with pancreatic cancer, 51 with chronic pancreatitis, and 36 with extrapancreatic diseases, mainly of gastrointestinal origin. Elastase-1, PLA2, and pancreatic isoamylase were increased in 56%, 25%, and 15% of patients with pancreatic cancer, and in 40%, 31%, and 41% of subjects with chronic pancreatitis. All four enzymes gave pathological values in a number of patients with extrapancreatic diseases. We conclude that the diagnostic efficacy of phospholipase A2 in chronic pancreatic disease is similar to that of other well known pancreatic enzymes, with an unsatisfactory sensitivity and specificity.

Adult↗