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Biomedical subjects

M Chiaramonte

Publications and source records attributed to M Chiaramonte.

50 records · Page 3Linked to original sources

Sodium retention in chronic liver disease: lack of a natriuretic factor?

An acute volume expansion in water diuresis has been induced in 8 patients with liver cirrhosis and in 8 normal subjects, taken as controls. A two hour postinfusion urine sample has been utilized to obtain the urine fraction with natriuretic activity. This activity was assayed in 16 rats. Our results confirm a significantly lower natriuretic activity of cirrhotic urine fractions than those of controls.

Animals

Detection, by three techniques, of hepatitis B surface antigen (HBsAg) and determination of HBsAg and anti-HBs titres in patients with chronic liver disease.

The sensitivities of three technqiues used to detect serum hepatitis B surface antigen (HBsAg) were compared in 411 patients with various types of chronic liver disease. Counterimmunoelectrophoresis proved an unreliable test. Two haemagglutination technqiues were slightly less sensitive than radioimmunoassay but were more rapidly performed. Less sensitive techniques were particularly unreliable in active liver disease where HBsAg titres were low. HBsAg was detected in patients with chronic persistent hepatitis, alcoholic liver disease, chronic active liver disease with or without cirrhosis, and primary liver cell carcinoma. Forty-six of the 68 (68%) HBsAg positive subjects were males coming from outside the United Kingdom. The HBsAg titres in 13 subjects with chronic persistent hepatitis were significantly higher (P less than 0-001) than those in 43 subjects with chronic active liver disease. Corticosteroid therapy did not alter the HBsAg titre significantly. None of the 28 HBsAg positive subjects studied serially for up to two years cleared HBsAg from the serum. Anti-HBs was examined by passive haemagglutination and found in 35 subjects, 26 of whom had no evidence of liver disease, 80% came from abroad. Anti-HBs was believed to be of epidemiological rather than of pathological importance.

Antibodies

Comparison between bolus injection and infusion of secretin and pancreozymin in the diagnosis of chronic pancreatic disease (one hour test).

There is no agreement in the literature as regards the carrying out of the Secretin-Pancreozymin test in order to achieve the greatest accuracy in the diagnosis of pancreatic insufficiency. In this study the results obtained by bolus i.v. injection of Secretin and Pancreozymin GIH are compared with those obtained by i.v. infusion of the hormones. The test - always prolonged for one hour - was done in 125 subjects, divided into two groups matched for sex, age and pancreatic or digestive disease. Volume, pH, bicarbonates, calcium and amylase were measured in the juice collected. The results showed that bolus i.v. injection of Secretin and Pancreozymin has greater diagnostic sensitivity (94%) than the infusion method (84%). If infusion is used, it is necessary to protract the test for more than one hour.

Adult

Immunological study of HB-AG carriers.

The serum immunoglobulin levels, the presence of circulating autoantibodies, the number of peripheral "atypical" lymphocytes and the number of DNA and RNA synthesizing mononuclear cells were studied in a group of "healthy" HB-Ag (australia Antigen) carriers and in a group of healthy HB-Ag negative control subjects. In the HB-Ag carriers, in spite of the persistent antigenaemia, all these immunological findings were normal (as in the control subjects).

Autoantibodies

Baseline seroepidemiology of hepatitis A virus infection among children and teenagers in Italy.

During the period from May 1987 through November 1989, the prevalence of antibodies to hepatitis A virus infection (anti-HAV) was assayed by the ELISA method in the serum samples of 5,507 (54% males, 46% females) apparently healthy subjects three to 19 years old in Italy. Subjects were selected by a systematic cluster sampling in five different geographical areas of Italy. The overall prevalence of anti-HAV was 9.5%; it increased from 2.3% among children three to five-years-old to 16.3% in teenagers 17 to 19 years old (p less than 0.001). A slight preponderance of females was observed (10% versus 9.1%), but the difference was not statistically significant. The prevalence was significantly higher in Southern Italy than in Northern Italy (27.4% versus 4.8%; p less than 0.01). The prevalence of anti-HAV was inversely related to the fathers' years of schooling (O.R. 3.3; 95% C.I. = 2.5-4.2) and positively related to the family size (O.R. 2.4; 95% C.I. = 1.9-3.1). These findings indicate that, today, exposure to HAV infection at a young age in Italy is very low. However, sociodemographic factors are still important determinants in the spread of this infection.

Adolescent

Biochemical markers of hepatic fibrosis in primary biliary cirrhosis.

We studied the behavior of some biochemical markers of fibrosis, the aminoterminal propeptide of type III procollagen (P-III-P), laminin, hyaluronate and fibronectin, in the sera of patients with primary biliary cirrhosis (PBC). Significant increases were found in serum laminin, hyaluronate and P-III-P and, more important, a significant correlation was found between the histological stage of the disease and serum hyaluronate. This parameter seems to distinguish between early PBC (I and II stages) and advanced disease with fibrosis. Moreover, a correlation between the histological stage and serum levels of both laminin and P-III-P was observed. Serum laminin, however, increases particularly in advanced disease, whereas high levels of sP-III-P are already present in the early stage. Finally, no significant differences were found between the plasma fibronectin levels of patients with primary biliary cirrhosis and those of controls.

Adult

Seroepidemiology of pertussis in Italy.

During 1988 and 1989 the prevalence of serum IgG antibodies to pertussis toxin in a sample of 3,875 unvaccinated, apparently healthy persons between the ages of 1 year to 19 years was estimated by enzyme-linked immunosorbent assay. The participants were recruited by means of systematic cluster sampling from public and private schools in five geographic areas of Italy. The overall prevalence of IgG antibodies was 80.8%, with a steady increase from 33.5% among 1- to 3-year-old children to 95% among 17- to 19-year-old individuals. The prevalence of natural immunity was 50% and 75% at the ages of 4 and 6 years, respectively. No gender-related difference in immunity was observed. For children greater than 10 years of age, the seroprevalence of pertussis antibodies was significantly higher in northern regions than in southern regions until the age of 17-19 years, when the pattern reversed. There was no association of a child's immune status with the father's number of years of schooling or with family size. For children aged 1-3 years, serologic studies showed that the history of pertussis reported by parents in questionnaires was highly specific (97.6%) in predicting antibody status, with positive and negative predictive values of 90.5% and 79.2%, respectively. However, 20.8% of children had antibodies to pertussis toxin even though they had no history of whooping cough.

Adolescent

Teaching gastroenterology using the problem-based learning method.

The need to change the methods of teaching medical students has become self-evident in the past two decades, and strategies for revision are indicated in the new course curriculum, Tabella XVIII. A modern teaching method is the problem-based learning (PBL) method, which has already been adopted by over 100 medical schools throughout the world. This method can also be a satisfactory tool for teaching gastroenterology to undergraduate students, and its implementation requires only a few resources that are available in most universities. The theoretical principles of the method are illustrated and practical suggestions are given to set up a course in gastroenterology using this method.

Education, Medical, Undergraduate

Changing epidemiology of hepatitis A virus (HAV) infection: a comparative seroepidemiological study (1979 vs 1989) in north-east Italy.

A comparative seroepidemiological study (1979 vs 1989) on HAV infection, was carried out in children and adolescents from North-East Italy. Anti-HAV was tested in 850 subjects 6 to 8 years of age and the results were compared to those observed in 1979, in 462 subjects of the same age range and from the same geographical area. Overall anti-HAV prevalence was 1.9% (ranging from 0.5 to 5.2) in 1989 vs 32.5% (ranging from 7.8 to 70.7) in 1979. This dramatic decline of HAV infection in children and adolescents reflects the improved sanitation standard of our country but, on the other hand, indicates that the number of non-immune adults is increasing, with a higher risk of symptomatic infection in the near future.

Adolescent

Changing pattern of hepatitis B infection in children: a comparative seroepidemiological study (1979 vs 1989) in north-east Italy.

Hepatitis B infection was endemic in Italy and household transmission has been considered to be the main mode of HBV spread. Prevalence of HBsAg positive subjects was therefore higher in children than in adults. Serum samples from 500 children (aged 6-15 year) without overt liver disease were tested for HBV serum markers in 1979. Serological evidence of HBV infection was present in 16% of the subjects. To verify a possible decline of HBV infection we designed a seroepidemiological study in school children from the same town. Three classes of age (6 yrs, 10 yrs, 14 yrs) were selected. Children were recruited from those attending primary and secondary schools using a systematic cluster sampling. After parents' informed consent sera were collected in May 1989. All were tested for anti-HBc: anti-HBc + ve sera were then tested for HBsAg and anti-HBs (EIA Abbott Lab., Chicago, Ill. USA). Of the 1635 children one was HBsAg positive and 21 were positive for any HBV marker. Both the prevalence of HBsAg and that of any HBV marker were significantly lower (p less than 0.001) in 1989 when compared to the corresponding age-class of 1979.

Adolescent