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Biomedical subjects

A T Muccioli

Publications and source records attributed to A T Muccioli.

6 recordsLinked to original sources

Altered T cell subsets and function in polytransfused beta-thalassemia patients: correlation with sex and age at first transfusion.

Monoclonal antibodies (OKT series) have been used to investigate possible modifications of T lymphocytes and T lymphocyte subsets in 65 multiply transfused beta-thalassemia patients. No significant difference was observed in percentage and absolute number of OKT3-, OKT4-, and OKT8-positive cells when compared to controls. A subgroup of patients (10 patients, 15.3%), however, could be selected who showed a reversal of OKT4/OKT8 ratio. These patients did not differ from the others as to age, number of transfusions, frequency of splenectomy, ferritin levels, hepatitis B markers, chronic liver disease incidence, and numbers of B lymphocytes and natural killer cells. The features distinguishing this group from the remaining patients were: decreased mitogen responsiveness; early age when first transfused; high incidence of males (90%). Immunological investigation was done in 2 occasions, 1 year apart, but no significant modification was observed in these patients. These findings suggest that in beta-thalassemia patients transfusion therapy started very early in life may be responsible for persistent immunological modifications. The susceptibility to such modifications might be greater in males.

Adolescent↗

Should hepatitis B surface antigen positive mothers breast feed?

Breast fed infants may be at greater risk of mother to infant hepatitis B virus infection compared with formula fed infants. We studied 85 infants born to 84 hepatitis B surface antigen positive mothers (only two of whom were hepatitis B e positive), and who had received immunisation against hepatitis B virus. Our results indicate that breast feeding does not increase the risk of developing hepatitis B virus infection in infants born to these mothers if immunisation is carried out.

Breast Feeding↗

Interference of hepatitis B virus surface antigen with natural killer cell function.

The influence of purified hepatitis B virus surface antigen (HBsAg) preparations or of supernatants derived from PLC/PRF/5 cell line (which produces HBsAg) on human natural killer (NK) activity was examined. Lymphocytes pre-incubated with HBsAg and subsequently washed showed a significant decrease in NK cytotoxicity against K-562 target cells. This effect was reversible and dose-dependent. In addition, pre-incubation with either HBsAg or PLC/PRF/5 supernatants inhibited in a reversible manner lymphocyte--K-562 conjugates and the binding of B73.1 monoclonal antibody (MoAb), which recognizes Fc receptors on NK cells. This effect was not observed with HNK-1, T3, T4, T6, T8 and T11 MoAb. HBsAg was non-toxic to lymphocytes, and ineffective with K-562 target cells. Beta-interferon did not modify HBsAg-mediated inhibition, when added either before or during the contact with HBsAg. Moreover, no modification was observed when neutrophils (at various neutrophil:lymphocyte ratios) were added, even though HBsAg is known to stimulate neutrophils to produce oxygen radicals which may modulate NK activity. We speculate that HBsAg produces these effects by reacting into receptor sites (possibly Fc receptor sites) on NK cell membrane. The overall significance of our results in relation to hepatitis and hepatocellular carcinoma is discussed.

Adult↗

T lymphocytes in children with recurrent respiratory infections: effect of the use of thymostimulin on the alterations of T-cell subsets.

OKT3-, OKT4- and OKT8-positive cells were estimated in 303 children with recurrent respiratory infections. The patients (selected by a score method) had experienced 13 or more infections a year. Modifications in T-cell subsets were observed in 154 patients (50.8%). Decreased OKT3- and OKT4-positive cells were present in 80 children (26.4%), while 74 patients (24.4%) showed normal values of OKT3-positive cells but decreased OKT4- and increased OKT8-positive cells. An attempt at treatment with thymostimulin was undertaken in a group of randomly chosen children with modifications in T-cell subsets. The use of thymostimulin induced the treated children more readily than the untreated ones to show improvement in both the score for respiratory infections and the distribution of T-cell subsets.

Antibodies, Monoclonal↗

[Biology of human immunodeficiency virus infection].

This review will describe the current state of basic knowledge on the acquired immune deficiency syndrome (AIDS), which has now spread worldwide becoming an acute public health problem in western countries and in Africa. AIDS is a viral infection, due to a retrovirus designated human immune deficiency virus (HIV), which affects the immune system resulting in a wide array of secondary manifestations which include opportunistic infections, neoplasia, autoimmune phenomena, neurologic disorders, and hematologic abnormalities. AIDS has now been recognized in the pediatric population, and infection occurs by perinatal and blood-borne transmission. As a consequence, pediatricians are no more involved only by a theoretical point of view (AIDS is a perfect model of interaction of virus with the immune system), but also by an operative point of view. Knowledges on immunological modifications in AIDS and on the underlaying features of the HIV are essential for the clinical approach. This goal may be difficult, if one considers that the pace of research in AIDS and the progress attained to date are unprecedent. However, clinicians must be aware that the ultimate solution of clinical problems in AIDS exclusively depends on sound basic research.

Acquired Immunodeficiency Syndrome↗