Search PubMed⌕ Search

Biomedical subjects

A Facchini

Publications and source records attributed to A Facchini.

At least 145 records · Page 8Linked to original sources
PubMed1984

Distribution of acid alpha-naphthyl acetate esterase among human T lymphocyte subsets.

Human T lymphocyte subsets, identified by means of OKT3, 4 and 8 monoclonal antibodies, were isolated by a fluorescence activated cell sorter (FACS IV) and analyzed for distribution of alpha-naphthyl acetate esterase (ANAE) activity. As compared to OKT8+ lymphocytes a higher proportion of OKT4+ lymphocytes was ANAE-positive exhibiting a spot or dot-like pattern in the cytoplasm. OKT8 and 4 positive subsets showed a similar ANAE distribution in diffuse granular form. Although OKT4 and OKT8 populations presented a different ANAE dot-like reactivity, this marker did not allow as clear a distinction between them as that reported for TG and TM lymphocytes.

Cell Separation↗
PubMed1984

Analysis with OKT monoclonal antibodies of T-lymphocyte subsets present in blood and liver of patients with chronic active hepatitis.

The relative distribution of T lymphocyte subsets, as defined by the monoclonal antibodies OKT, was determined by cytofluorimetric analysis in peripheral blood and in cells isolated from liver biopsies of 31 patients with chronic active hepatitis (CAH). The percentage of peripheral blood lymphocytes binding OKT8 (directed against cytotoxic/suppressor T cells) was found to be elevated in patients with HBsAg and HBeAg positive chronic active hepatitis. Patients with CAH who had seroconverted to anti-HBe, had an increased number of OKT3-positive cells in their blood, which was directed against a common T cell surface antigen, associated with a decreased number of OKT8 positive cells. Lymphocytes isolated from liver biopsies of patients with CAH presented a general increase of OKT8-positive cells associated with a decreased number of OKT4-positive (helper/inducer) T cells. It is likely that OKT8-positive cells found in liver biopsies represent cytotoxic T cells directed against either viral or liver cell determinants.

Adult↗
PubMed1983

Lymphocytotoxicity against autologous hepatocytes and membrane-bound IgG in viral and autoimmune chronic active hepatitis.

Membrane-bound IgG and lymphocytotoxic activity of total, T-enriched and T-depleted lymphocytes, using autologous hepatocytes have been evaluated in: (a) 31 patients with chronic active hepatitis (CAH) (six autoimmune and 25 hepatitis B virus - HBV-related); (b) five patients with inactive alcoholic cirrhosis; and (c) nine subjects with normal hepatic histology. Lymphocytotoxicity was positive in 83% of autoimmune CAH and 68% of HBV-related cases; it was confined to the T-depleted subpopulation in the first group, while it was present in both the T-enriched and T-depleted subpopulations in 81% of HBV-related cases. Membrane-bound IgG was present in 58% of group (a) and in none of the other groups. A linear pattern was found in four out of five autoimmune CAH patients with positive lymphocytotoxic activity. The autoimmune patient with lymphocytotoxic activity within the normal range did not show any membrane fluorescence. Among HBV-related CAH patients, 13 presented a granular pattern, two an associated granular and linear pattern and ten were negative. These data suggest that different lymphocytotoxic mechanisms are involved in the two forms of CAH studied.

Autoantibodies↗
PubMed1981

Radioimmunoassay for hepatitis B 'e' antigen and antibody: correlations with viral replication and prognostic value.

The presence of hepatitis B 'e' antigen (HBeAg) and its antibody (anti-HBe was evaluated by radioimmunoassay (RIA) in various groups of HBsAg-positive patients. HBeAg was present in the majority of the sera from patients with acute viral hepatitis at onset of clinical symptoms and disappeared after 1 year. Almost all hemodialysis patients had HBeAg in their sera. 40% of the patients who had chronic active hepatitis and 50% with chronic persistent hepatitis had HBeAg with no relationship to the inflammatory activity of the disease evaluated by the presence of mononuclear infiltration in liver biopsy. The comparison between the presence of HBeAg and Dane particle-associated DNA-polymerase activity showed that HBeAg was consistently found in almost all the sera which presented DNA-polymerase activity. HBeAg, as determined by RIA, may therefore be useful in the screening of highly infective patients with elevated viral replication.

Antibodies, Viral↗
PubMed1981

Different mechanisms of "in vitro' lymphocytotoxicity against isolated rabbit hepatocytes during the course of acute viral hepatitis.

In order to characterize the effector mechanism of "in vitro' lymphocytotoxicity against isolated rabbit liver cells in acute viral hepatitis (AVH), the test was performed in 4 patients with type A, in 8 with type, B, and in 2 patients with non-A non-B AVH: (a) using peripheral blood lymphocytes; (b) after enzymatic digestion of the surface membrane immunoglobulins of these lymphocytes, and (c) as in b with addition of patients' sera. 78.5% of the patients had an elevated cytotoxicity which did not change when the lymphocytes were treated as in b and c. Only the 2 patients which progressed to chronicity had an elevated cytotoxicity which disappeared after enzymatic exposure and reappeared with the addition of patients' sera. The results suggest that "in vitro' cytoxicity in recovering AVH is not antibody dependent, but probably of spontaneous type. On the contrary an antibody-dependent cytotoxicity is present in the 2 cases of AVH who progressed to chronicity.

Adolescent↗
PubMed1981

Antibodies against human liver-specific protein (LSP) in acute and chronic viral hepatitis types A, B and non-A, non-B.

Sera from 42 patients with acute viral hepatitis (AVH), 97 patients with chronic active liver disease (CALD) and 89 controls were tested by radioimmunoprecipitation for the presence of antibodies against human liver-specific protein (LSP). Anti-LSP were found in all but one patient with AVH type A (93%) and in a smaller percentage of AVH type B (55%). In non-A, non-B cases, anti-LSP were found in low percentages: 27% in acute cases, 10% in chronic cases. Furthermore, in CALD, a significant difference was found between HBsAg-positive CAH and 'autoimmune' CAH, a significant difference was found between HBsAg-positive CAH and 'autoimmune' CAH, both in anti-LSP prevalence (21%, 67%; P less than 0.005) and in anti-LSP titre (1:154 +/- 170, 1:316 +/- 186; P less than 0.005). In HBsAg-negative/anti-HBc-positive CAH, three of 15 patients were anti-LSP positive. Anti-LSP were found only in three of 57 patients with various non-hepatic diseases with autoimmune features. None of the 12 healthy HBsAg carriers was positive. Hence there is evidence for a considerable heterogeneity in anti-LSP response in acute and in chronic inflammatory HBsAg-negative liver diseases. These data suggest that anti-LSP antibodies do not play a prominent role in the process of transition to chronicity of acute viral hepatitis particularly in non-A, non-B cases, whereas these antibodies may be important in the mechanism of ongoing liver cell injury in patients with 'autoimmune' CAH, and can represent a useful diagnostic marker of this type of hepatitis.

Acute Disease↗
PubMed1981

Non-histone chromatin proteins in human thymocytes and T lymphocytes from blood.

The composition of nuclear proteins from human thymocytes and T lymphocytes from peripheral blood was analyzed. Total thymocytes and total peripheral blood T lymphocytes differed markedly in non-histone chromatin proteins (both phosphorylated and non-phosphorylated), but did not differ in histones. When the cells were separated according to density, T-lymphocyte fractions with a close specific gravity showed restricted differences in non-histone chromatin patterns.

Cell Count↗
PubMed1980

[Separation and characterization of human T G and T M lymphocyte populations].

During the last few years a number of experimental evidences have shown the presence of Fc receptors for IgG or IgM on the membrane of human T cells. These two different receptors are detectable and mutually exclusive on distinct cell populations named respectively TG, TM and T "null" (which lack detectable receptors). Studies on the functional activities of these cells have shown that TM and TG lymphocytes play an antitetical role in regulating B cell response, TM exerting an "helper" activity on the differentiation of B lymphocytes while TG having a "suppressor" one. The aim of this study has been to determine the values of these two subpopulations in a group of twenty control subjects. Our results have shown that TG constitute 10%, whereas TM represent 40% of the total T cells. After EA-G rosetting, the purification of this subpopulation on a density gradient has shown an enrichment of more than 90% in TG cells, while TM contaminate this fraction for less than 4%. The purity of the fraction containing TM has been evaluated using the localization of alpha-naphthyl acetate esterase activity, which has shown that more than 88% of the cells in this fraction are positive for this enzyme.

Adult↗
PubMed1980

[Liver cell membrane autoantibody (LMA) in chronic liver disease].

The incidence of LMA, detected by indirect IF on isolated rabbit hepatocytes, was significantly higher in CAH-non B (58%) than in CAH-B (15%). Sera from AVH patients showed a smaller percentage of positivity whereas the CPH patients were negative. The organ-specificity, the high incidence in relation to other non-organ-specific autoantibodies and the inverse correlation with the markers of HB Virus, make LMA a specific and sensitive marker of "autoimmune" chronic liver disease.

Acute Disease↗
PubMed1979

[Surface immunoglobulins (SmIg) in human B-lymphocytes: effect of enzymatic digestion].

In order to determine the number of circulating B lymphocytes which can synthetize their surface membrane immunoglobulins, we have evaluated by immunofluorescence their presence before and after enzymatic exposure to pronase. After pronase treatment the majority of lymphocytes carrying SmIg has been disappeared (from 7.8% to 1.9%; p < .0.0005). After 18 hours incubaton only a small proportion (4.6%) of B lymphocytes risynthetized their SmIg. This observation support the hypothesis that a subset of lymphocytes present in the peripheral blood carries on its membrane only cytophilic SmIg and therefore may interfere in the determination of the number of B lymphocytes.

Adult↗
PubMed1979

[Lymphocytotoxicity in alcoholic hepatitis: evalutation of effector cells].

Alcohol induced liver damage has been recently suggested to occur in some cases as a consequence of a true autoimmune reaction. However the nature of the effector cells is still debated. Microlymphocytotoxicity "in vitro" test against rabbit hepatocytes has been performed in 29 patients with alcoholic cirrhosis and 8 with acute alcoholic hepatitis. The diagnosis has been done on clinical and histological grounds. The mean cytotoxicity index (CI) of subjects with alcoholic cirrhosis was 15.12 +/- 14.18 and with acute alcoholic hepatitis 62.49 +/- 16.33 (normal range: 0 -37.90). To further characterize the effector cells in our system, the test has been performed again either using T-enriched fractions of peripheral lymphocytes or after pronase-induced digestion of SmIg of total lymphocytes in 5 patients with acute alcoholic hepatitis and high CI. In both instances a disappearance of citotoxic activity has been observed. These data suggest: a) autoimmune reaction can occur only in patients with acute alcoholic liver damage; b) non T-cells are responsible for cytotoxicity; c) the immune reaction appears to be of cell-mediated antibody-dependent type.

Adolescent↗
PubMed1978

Lymphocytotoxicity test against rabbit hepatocytes in chronic liver diseases.

We have studied the cytotoxicity against rabbit liver cells of lymphocytes from the peripheral blood of 71 patients with various liver diseases. The group with chronic active hepatitis and three patients with acute alcoholic hepatitis showed significantly higher mean values of lymphocytotoxicity (P less than 0.001) compared with the other patients with chronic persistent hepatitis, post-necrotic fibrosis and cirrhosis. Wilson's disease, and prolonged viral hepatitis. The mean cytotoxicity of these last groups did not differ significantly from controls. In four out of six patients with chronic active hepatitis a significant decrease of lymphocytotoxicity was found after immunosuppressive therapy with oral prednisolone. A good correlation between the lymphocytotoxicity test and histological signs of activity suggests that a cell-mediated immune aggression is present in this disease.

Adolescent↗