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Biomedical subjects

R Rizzi

Publications and source records attributed to R Rizzi.

At least 73 records · Page 4Linked to original sources
PubMed1984

Interaction of acrylonitrile with the liver mixed function oxidases.

The effect on the liver mixed function oxidases of acrylonitrile revealed an inhibition of the benzo(a)pyrene hydroxylase and of the epoxide hydrase whereas aniline hydroxylase is unaffected. These findings exclude the possibility that the inhibitory effect of certain hydroxylation activities of the liver microsomes can be secondary to a direct effect of acrylonitrile on cytochrome P-450 but suggest the hypothesis that the inhibition is mediated by the cyanide released during acrylonitrile metabolism.

Acrylonitrile↗
PubMed1983

HBsAg/IgM complexes in serum of HBsAg carriers: partial characterization and clinical significance.

HBsAg bound to IgM was detected in serum of HBsAg carriers with a radioimmunoassay based on selective absorption of the immunoglobulin on a solid phase coated with antiserum to human IgM. High titers of HBsAg/IgM were found in sera with the highest HBsAg binding capacity of polymerized human serum albumin (poly-HSA) and of C1q. These findings and the inhibition of HBsAg/IgM reaction by addition of purified poly-HSA suggest that the IgM component of the complex might bind to poly-HSA fixed on to HBsAg particles and possibly represent antibody to the modified plasma protein. HBsAg/IgM was detected in 95 (87%) patients with acute HBsAg positive hepatitis during the acute phase of infection and persisted after the fourth week only in patients who developed chronic liver disease. HBsAg/IgM were detected in one out of 15 carriers of the HBsAg with superimposed Non B hepatitis. HBsAg/IgM were also present in 76% to 100% of sera from chronic carriers without any relation to the extent of viral replication and to presence of severity of liver disease. Persistence of HBsAg/IgM in patients with acute hepatitis B may provide a useful tool to predict transition of HBV infection to chronicity.

Acute Disease↗
PubMed1983

Complexes between HBsAg and IgM in serum of patients with acute hepatitis.

HBsAg bound to IgM was measured in the serum of HBsAg carriers with acute hepatitis using a radioimmunoassay based on selective absorption of IgM on solid phase coated with antiserum to human IgM. HBsAg/IgM was detected in 94 (100%) patients with acute type B hepatitis during the acute phase of infection and persisted after the fourth week only in 13 of them, who developed chronic liver disease. HBsAg/IgM was detected only in 1 patient out of 15 carriers of the HBsAg with superimposed non-B hepatitis. No activity was found in serum of 20 patients with acute HBsAg-negative hepatitis. The nature of the IgM component of the complex is uncertain, however, blocking experiments of the HBsAg/IgM reaction with polymerized human albumin suggest that the IgM component of the complex might represent antibody to the denatured protein. Persistent HBsAg/IgM complex detection in patients with acute type B hepatitis provides a useful tool to predict transition of HBV infection to chronicity. Its absence in patients with acute HBsAg-positive hepatitis is indicative of non-B hepatitis in chronic carriers of the HBsAg.

Acute Disease↗
PubMed1983

Chromosome damage in heroin-marijuana and marijuana addicts.

The aim of this study was to determine the frequency of chromosome damage in heroin-marijuana addicts and marijuana addicts. A group of 45 subjects, aged between 19 and 21 years, was divided into 15 controls, 15 heroin-marijuana addicts and 15 marijuana addicts. These patients were examined for the presence of chromosome aberrations in their peripheral lymphocytes. The findings indicate that the incidence of chromosome anomalies in heroin-marijuana addicts is approximately 21.3 times greater than in the controls and approximately 7.9 times greater than in marijuana addicts.

Adult↗
PubMed1983

Complexes of hepatitis B surface antigen and immunoglobulin M in the sera of patients with hepatitis B virus infection.

Hepatitis B surface antigen (HBsAg) bound to immunoglobulin M (IgM) was detected in sera of HBsAg carriers by a radioimmunoassay based on selective absorption of the immunoglobulin on a solid phase coated with antiserum to human IgM. Isopycnic banding and rate-zonal sedimentation have shown that the reaction is related to particulate forms of the HBsAg complexed with IgM. The binding of IgM possibly occurred because of a selective affinity of these molecules to the surface of HBsAg particles. HBsAg/IgM was found transiently in 24 of 25 (96%) patients with acute self-limited hepatitis B and persistently in 6 of 25 patients whose acute hepatitis B progressed to chronicity. It was also found in 20 of 39 (51%) chronic HBsAg carriers with inactive and asymptomatic infection. The HBsAg/IgM phenomenon is not dependent on replication of hepatitis B virions; its persistence in patients with acute hepatitis B may provide complementary evidence of transition of the infection to chronicity.

Animals↗
PubMed1980

[Anesthesiological problems in the correction of craniofacial malformations].

The various anaesthesiological problems that arise in the execution of multiple osteotomies for the correction of craniofacial deformities are examined. The period of anaesthesia may be prolonged for over 1 hours and the various biological constants must be rhythmically checked and corrected to ensure a successful result.

Adolescent↗