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Biomedical subjects

M Rizzetto

Publications and source records attributed to M Rizzetto.

At least 325 records · Page 18Linked to original sources
PubMed1977

Localization of carcinoembryogenic antigen (CEA) in normal, inflammatory and neoplastic colonic mucosa by immunofluorescence.

To evaluate the role of tissutal carcinoembryonic antigen (CEA) in different types of colonic mucosae specimens from normal, inflammatory and neoplastic tissues were examined in immunofluorescence (IFL) with a monospecific CEA antiserum. Neither the pattern of IFL nor the amount of antigen in the tissue (defined as the antiserum dilution beyond which CEA staining was no longer visible), could reliably distinguish any histological entity a consistent overlap being observed between positive and negative results in malignant and non malignant mucosa. No correlation was found betwen IFL and the level of serum CEA. It is concluded that the tissutal localization of CEA by immunohistochemistry plays no role in the differential diagnosis of different types of colonic mucosa.

Carcinoembryonic Antigen↗
PubMed1977

A trichrome stain for the intrahepatic localization of the hepatitis B surface antigen (HBsAg).

A modified trichrome stain is described for the intrahepatic localization of the hepatitis B surface antigen; HBsAg containing cells exhibit specific green metachromasia contrasting with the granular brown colour of non infected hepatocytes and with the deep eosinophilic colour of ground glass cells of HBsAg-negative alcoholic or drug hepatitis. The technique is simple and reliable for routine screening of HBsAg positive material; its sensitivity is greater than H & E, similar orcein and inferior to immunohistochemistry as performed on frozen sections. Histological diagnosis can be made on the same slide, since several other morphological details are provided in the trichrome stained preparations. With this technique 387 biopsies from HBsAg seronegative individuals were negative; full cytoplasms metachromasia was mostly seen in asymptomatic HBsAg carriers, focal or partial staining in patients with histological evidence of liver cell necrosis. The presence and the staining pattern of HBsAg were of no help in predicting transition to chronicity or a transition from chronic persistent to chronic active hepatitis.

Azo Compounds↗
PubMed1977

Immunofluorescence detection of new antigen-antibody system (delta/anti-delta) associated to hepatitis B virus in liver and in serum of HBsAg carriers.

A new antigen-antibody system associated with the hepatitis B virus and immunologically distinct from the HB surface, core, and e systems is reported. The new antigen, termed delta, was detected by direct immunofluorescence only in the liver cell nuclei of patients with HBsAg positive chronic liver disease. At present, the intrahepatic expression of HBcAg and delta antigen appears to be mutually exclusive. No ultrastructural aspect corresponding to the delta antigen could be identified under the electron microscope. delta antibody was found in the serum of chronic HBsAg carriers, with a higher prevalence in patients with liver damage. The nuclear fluorescence patterns of HBcAg and delta antigen were similar; it is only possible to discriminate between the two antigens by using the respective specific antisera.

Adult↗
PubMed1977

G-cell counts in antral endoscopic biopsies by immunofluorescence.

Antral gastrin-producing cell (G-cells) were counted by an immunofluorescence technique in the antral biopsies obtained at endoscopy from 67 subjects; they included patients with duodenal ulcer, gastritis, and individuals with a normal gastric mucosa. The G-cell count was significantly lower (P less than 0.01) in patients with duodenal ulcer (142 G cells per mm2) in comparison to normal subjects (327 G cells per mm2). No statistically significant correlation was found between the G-cell number and any of the other parameters tested (pentagastrin test, basal serum gastrin and its response to a standard meal).

Adolescent↗
PubMed1976

Prognostic significance of in-vitro complement fixation in liver biopsy specimens from patients with acute viral hepatitis type B.

The prognostic significance of in-vitro complement fixation (V.C.F.) by hepatitis-B core antigen/antibody immunocomplexes in hepatitis-B surface antigen (HBsAg) positive liver biopsy specimens was prospectively evaluated in 47 patients presenting with acute viral hepatitis type B. 34 of 37 V.C.F.-negative patients made an uneventful recovery and became HBsAg negative; in all patients with a V.C.F.-positive test chronic hepatitis and persistent antigenaemia developed. The V.C.F. test is a simple and reliable prognostic indicator of persistent infection and of progression of apparently acute hepatitis to a chronic liver disorder.

Acute Disease↗
PubMed1976

[Pseudomembranous colitis caused by antibiotics].

Six cases of pseudomembranous colitis caused by antibiotics are presented. The endoscopic, radiological and clinical picture and the aetiopathogenesis of this unusual disease are discussed. Lincomycin was incriminated in one case only. In the remainder, various antibiotics of different chemical structure were responsible. Carcinoma of the colon was a common feature and it is suggested that a full examination of the large intestine should be made whenever this syndrome appears. While radiological suspicion may be forthcoming, pseudomembranous colitis is diagnosed only by endoscopy and biopsy.

Adenocarcinoma↗
PubMed1976

Complement fixing hepatitis B core antigen immune complexes in the liver of patients with HBs antigen positive chronic disease.

One hundred and fifty-two biopsies from serologically HBsAg positive and negative patients with liver disease were studied in immunofluorescence: for the presence of the surface (HBs) and the core (HBc) antigenic determinants foeterminants of the hepatitis B virus, of immunoglobulins and complement (C) deposits, and for the capacity to fix human C. Circumstantial evidence is presented suggesting that HBc immune-complexes are a relevant feature in the establishment and progression of chronic HBSAg liver disease. C fixation by liver cells was shown in all HBC positive patients with chronic hepatitis; an active form was present in every case, except two with a persistent hepatitis, an inverse ratio of HBc to C binding fluorescence being noted between active chronic hepatitis and cirrhotic patients. HBc without C fixation was observed in only three patients in the incubation phase of infectious hepatitis. IgG deposits were often found in HBc containing, C fixing nuclei. No C binding or IgG deposits were observed in acute self-limited type B hepatitis, in serologically positive patients with normal liver or minimal histological lesions, with and without HBs cytoplasmic fluorescence in their biopsy, or in serologically negative individuals.

Adolescent↗
PubMed1975

[Chronic hepatitis: diagnostic and therapeutic problems].

The morphological criteria for diagnosing chronic hepatitis are discussed and criticised. A classification closer to clinical reality than that of De Groote et al 1968 is then proposed. Personal experience in differential laboratory diagnosis between the various forms of chronic hepatitis by means of comparative evaluation of an enzymogram and the measurement of certain proteins in the serum is then reported. Case examples are given to emphasise the possibilities of the immunological approach to the problem of active chronic hepatitis. Finally, the cardinal points of therapy are reviewed.

Adult↗
PubMed1974

Hepatic disorders associated with liver-kidney microsomal antibodies.

A study of the clinical associations of a recently defined tissue autoantibody, the liver/kidney microsomal (L.K.M.) antibody, showed that out of 33 patients 26 had clinical liver disease. Fifteen of the patients had active chronic hepatitis and there were seven cases of acute hepatitis, precipitated by presumed virus A infection in three instances and by drug hypersensitivity in the other four. The remaining cases with liver disease included two with subclinical hepatitis and two with hepatocellular carcinoma. Evidence is presented that the patients with active chronic hepatitis may represent a distinct subgroup of the disease with a young mean age, an even male to female ratio, and a striking lack of other nonorgan-specific autoantibodies-that is, antinuclear and smooth muscle-which are usually present in the other autoimmune variant of the disease.

Adolescent↗
PubMed1973

Types of 'reticulin' antibodies detected in human sera by immunofluorescence.

Reticulin antibodies have been classified by immunofluorescence into five types reacting with distinct antigens of intra- and extracellular components in mesenchyme. Two types of fibrillar antigens can be distinguished on the basis of the staining patterns, anatomical distribution, and species specificity. A third antibody reacts with either small fibres, amorphous proteins, or mucopolysaccharides lining the hepatic sinusoids (ground substance antigens). In addition, at least two kinds of intrasinusoidal cells show cytoplasmic fluorescence, ie, Kupffer cells and glass-adherent, blood-borne cells antigenically related to peritoneal macrophages. Some sera may contain antibodies reacting with sinusoidal endothelial cells though this has not yet been proven. It has been confirmed that all these distinct antibodies related to reticulin antigens are most frequent in dermatitis herpetiformis and coeliac disease, but they are also found with increased frequency in chronic heroin addicts and in rheumatoid and Sjögren's syndromes. About 5% of normal individuals had such antibodies and no significant increase could be demonstrated in autoimmune disorders or in liver cirrhosis. The antibodies appear to be stimulated by bacterial or nutritional antigens and are likely to represent anamnestic responses rather than direct cross reactions with a multiplicity of foreign antigens.

Animals↗
PubMedDate not supplied

Experimental HBV and delta infections of chimpanzees: occurrence and significance of intrahepatic immune complexes of HBcAg and delta antigen.

The occurrence and pathogenetic role of intrahepatic deposits of immunoglobulins in experimental viral infection have been evaluated by determining with immunofluorescence their capacity to fix complement in vitro [in vitro complement fixation (VCF)]. Liver biopsies from chimpanzees chronically or acutely infected with hepatitis B virus or the hepatitis B surface antigen (HBsAg)-associated delta agent were used in the study. VCF was observed in each animal expressing hepatitis B core antigen (HBcAg) or delta antigen in the liver and concurrently circulating the homologous antibody in the blood. In acutely infected animals, VCF appeared at the same time that the homologous serum antibody appeared, and the intensity of VCF staining was proportional to the antibody titer in the serum. In animals expressing sequentially the HBcAg/antibody system and then delta antigen and antibody to delta, VCF was first observed in HBcAg-containing nuclei and then in nuclei expressing delta antigen. There was no relationship between VCF and intrahepatic expression of HBsAg or serologic expression of hepatitis B e antigen (HBeAg). A positive VCF reaction appears related to the formation of intrahepatic immune complexes between HBcAg or delta antigen and the homologous antibody. Although acute hepatitis developed in parallel with the occurrence of VCF in two animals, strong VCF fluorescence was also observed in each of the asymptomatic carriers of HBsAg, and, in one of them, preexisting VCF staining of HBcAg disappeared in parallel with development of acute hepatitis. In experimentally infected chimpanzees, the finding in liver biopsies of immune complexes detectable by VCF appears to be a common epiphenomenon without pathogenic significance.

Animals↗
PubMedDate not supplied

Dane particle-associated hepatitis B e antigen in patients with chronic hepatitis B virus infection and hepatitis B e antibody.

A commercial radioimmunoassay was adapted to detect serum Dane particle-associated HBeAg in patients whose sera contained homologous antibody. HBeAg was released from Dane particles with guanidine HCl. Dane particles were separated from anti-HBe by gel-filtration (Sepharose 4B) and ultracentrifugation of the eluate. Dane particle-HBeAg was tested in 45 HBsAg carriers with anti-HBe and was present in 8 (18%) carriers, all of whom had chronic liver disease. By contrast, HBeAg was not found in 10 carriers with normal liver histology. Serum or liver HBcAg was found in 6 of 8 patients with Dane particle-HBeAg. None of the carriers without Dane particle-HBeAg had other markers of hepatitis B virion synthesis. We conclude that Dane particle-HBeAg provides a sensitive index of active hepatitis B virus replication, a guide to the presence of chronic hepatitis in HBsAg carriers with anti-HBe, and a noninvasive method to follow infection in these patients.

Antibodies, Viral↗