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Biomedical subjects

A Musca

Publications and source records attributed to A Musca.

At least 55 records · Page 3Linked to original sources
PubMed1985

Immunoregulation of the in vitro anti-HBs antibody synthesis in chronic HBsAg carriers and in recently boosted anti-hepatitis B vaccine recipients.

We report a study on immunoregulation of in vitro antibody to hepatitis B surface antigen (anti-HBs) synthesis induced by pokeweed mitogen (PWM) from peripheral blood mononuclear cells (PBMC) in chronic hepatitis B surface antigen (HBsAg) carriers and in 'high responders', (anti-HBs RIA ratio greater than or equal to 20 in serum), recently boosted with anti-hepatitis B vaccine. Anti-HBs was detected in 11 days PBMC supernatants (SN) from 24 out of 36 'high responders', but in none from 31 chronic HBsAg carriers, despite detectable amounts of polyclonal IgG and antibody to hepatitis B core antigen (anti-HBc) were produced. The lack of anti-HBs production by chronic HBsAg carriers did not seem to be determined by suppressor influences because T lymphocytes from the majority of chronic HBsAg carriers, co-cultured with 'high responders' PBMC did not suppress anti-HBs production. Co-cultures between HBsAg carriers T4 positive (helper/inducer) cells and allogenic 'high responder' non-T cells produced anti-HBs antibody, indicating that HBsAg carrier T cells are not deficient in this allogenic helper function under PWM stimulation. Allogenic cocultures between HBsAg carrier non-T cells and 'high responder' T4 positive cells failed in anti-HBs production: a specific B lymphocyte defect might be involved in the lacking anti-HBs synthesis in chronic HBV patients. Antigen-induced specific anti-HBs synthesis experiments indicate that B cells themselves seem to be the target for HBsAg-induced suppression of anti-HBs antibody response.

Adolescent↗
PubMed1984

Influence of vitamin E on plasma malondialdehyde-like material in man.

The behaviour of plasma malondialdehyde-like material (MDA-LM) was evaluated in 13 healthy subjects by a single-blind study that consisted of placebo (30 days), vitamin E treatment (300 mg/day) (30 days) and placebo (30 days). The study demonstrated that MDA-LM did not change during placebo treatment while it significantly decreased after vitamin E administration.

Adolescent↗
PubMed1984

Apolipoproteins A-I, A-II and B in chronic active hepatitis and in liver cirrhotic patients.

Apolipoproteins A-I, A-II and B were evaluated in 18 chronic active hepatitis and 27 liver cirrhotic patients. The latter were also divided into compensated and decompensated subgroups. Significantly low values of apolipoproteins A-II and B were seen in chronic active hepatitis and liver cirrhotic patients, while apolipoprotein A-I was decreased in liver cirrhotic patients only. Chronic active hepatitis had higher apolipoprotein values than liver cirrhosis and in the latter one decompensated subgroup showed lower apolipoprotein levels than the compensated one. Apolipoproteins A-I, A-II and B correlated also well with prothrombin activity (Normotest) in liver cirrhotic patients, especially the apolipoprotein A-II values. This study suggests that serum values of apolipoproteins are affected by the type of liver damage and that their decrease could be partly due to impaired liver synthesis.

Adult↗
PubMed1984

Prekallikrein behaviour in chronic active hepatitis and in cirrhotic patients.

Prekallikrein (Prekk), antithrombin III (ATIII), plasminogen and alpha 2-antiplasmin were evaluated in chronic active hepatitis and in liver cirrhotic patients and correlated with Normotest. Prekk, ATII and plasminogen were significantly decreased in chronic active hepatitis as well as in liver cirrhosis. Alpha 2-antiplasmin levels in chronic active hepatitis patients did not differ from controls; liver cirrhotic patients, on the contrary, showed significantly low values of alpha 2-antiplasmin, Prekk, ATIII and plasminogen were significantly correlated with Normotest in both groups, but when cirrhotic patients were divided into the compensated and decompensated state only Prekk was correlated with Normotest in the decompensated state. The investigation seems to suggest that Prekk could be a reliable index for protein liver failure.

Adult↗
PubMed1984

Circulating HBsAg/IgM complexes in acute and chronic hepatitis B.

Complexes between HBsAg and IgM have recently been described in the sera of HBsAg carriers. A solid phase RIA for HBsAg/IgM complexes has been described. Fifteen patients with acute viral hepatitis type B, and 52 HBsAg chronic carriers were studied. Testing of serial sera in acute hepatitis patients revealed that HBsAg/IgM complexes disappeared (preceding HBsAg negativization and usually at the same time as seroconversion from "e" to "anti-e") with 4 weeks in all but one patient who became a chronic HBsAg carrier. In addition, HBsAg/IgM complexes were found in 48% of HBsAg chronic carriers, in 69% of CPH patients, but in only 20% of healthy carriers (p less than 0.005). Although complexes were detectable in 93% HBeAg positive chronic carriers, they were also frequently found in anti-HBe positive patients, but never in e/anti-e negative patients (p less than 0.001). HBsAg/IgM complexes seem to be of important prognostic and diagnostic value in acute and chronic hepatitis B.

Antigen-Antibody Complex↗
PubMed1983

Relationship between T cell subsets and suppressor cell activity in chronic hepatitis B virus (HBV) infection.

The relationship between T cell subset, as defined by monoclonal antibodies, and suppressor cell function, using a short lived suppressor cell assay, was studied in 38 chronic hepatitis B virus (HBV) carriers and in 32 patients with HBsAg negative chronic active hepatitis (CAH). Patients with HBV chronic infection showed an absolute reduction in the OKT4 positive subset and a significantly decreased OKT4/OKT8 ratio, as compared with healthy controls. Patients with anti-nuclear antibodies (ANA) and anti-smooth muscle antibodies (ASMA) positive CAH with or without antibodies to HBV antigens, namely anti-HBs and anti-HBc, demonstrated a significant reduction in cytotoxic/suppressor T cells and an increased helper/suppressor ratio. A negative correlation between suppressor index (SI) and OKT4/OKT8 ratio (P less than 0.01), and a positive correlation between SI and OKT8 positive cells absolute number (P less than 0.01) were also observed.

Antibodies, Antinuclear↗
PubMed1983

HBeAg/anti-HBe system and development of primary hepatocellular carcinoma in patients with HBsAg-positive liver cirrhosis.

The significance of the HBeAg/anti-HBe system and other HBV markers in the evolution of HBsAg-positive liver cirrhosis to primary hepato-cellular carcinoma (PHC) was studied by following up 70 cirrhotic patients from February 1978 to February 1981. Eight out of 19 (42.1%) patients with HBsAg positive liver cirrhosis developed PHC. On the other hand, only 7.8% of the patients with HBsAg-negative liver cirrhosis developed PHC. In the HBsAg-positive group only the patients who had already seroconverted to anti-HBe (7 out of 11) or were negative for both HBeAg and anti-HBe (1 out of 3) at the time of first observation and showed a histological picture of inactive cirrhosis, developed PHC during the follow-up period. No HBeAg-positive cirrhosis showed such an evolution. The absence of HBeAg in the sera of patients who developed PHC suggests that active HBV replication becomes increasingly defective during the course of malignant transformation.

Antibodies, Viral↗
PubMed1982

Influence of ascorbic acid on platelet aggregation in vitro and in vivo.

With the objective of investigating more thoroughly the relationship between ascorbic acid and platelet aggregation (PA) in particular, in vitro and in vivo studies were made whether interferences exist, Scaling amounts of ascorbic acid were added to platelet-rich plasma (PRP) samples to determine the level at which the inhibition of the PA was induce by ADP and arachidonic acid (AA), and endoplatelet malondialdehyde (MDA) concentrations decreased. Changes in PA and MDA were not observed in the PRP control samples Also, in 10 healthy volunteers, an i.v. infusion of ascorbic acid (2 g) produced PA inhibition and a reduction of MDA concentrations.

Ascorbic Acid↗
PubMed1982

Improvement of some blood coagulation factors in cirrhotic patients treated with low doses of heparin.

Effects of subcutaneous calcium-heparin and vitamin K administration were studied in 30 cirrhotic patients showing low values of prothrombin time, antithrombin III, fibrinogen, platelet count, plasminogen, alpha 2-antiplasmin, raised levels of fibrin(ogen) degradation products and prolonged activated partial thromboplastin time. A group of 10 patients was first treated with K vitamin for 15 d; after vitamin K therapy interruption, a treatment with 5000 IU (8000 IU in 1 patient) every 12 h of subcutaneous calcium-heparin was started. In another group of 20 patients a treatment with 5000 IU (8000 IU in 2 patients) every 12 h of subcutaneous calcium-heparin was started immediately. The heparin administration in both groups had been performed for at least 2 weeks. No significant changes of blood coagulation picture were observed after vitamin K administration, while calcium-heparin treatment showed an increase in prothrombin time, fibrinogen, platelet count, plasminogen, alpha 2-antiplasmin, a decrease in fibrin(ogen) degradation products and a shortened activated partial thromboplastin time. There was no significant change in antithrombin III values.

Blood Coagulation Factors↗