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Biomedical subjects

A Carbone

Publications and source records attributed to A Carbone.

At least 487 records · Page 27Linked to original sources
PubMed1986

The mature, mitogen-responsive, human thymocyte population comprises two functionally distinct T-cell subsets differing in exogenous interleukin requirements for mitogenesis and in sensitivity to glucocorticoids.

Human thymocytes were separated into 10 fractions by continuous Percoll density gradient centrifugation. Almost all the cells able to proliferate in response to phytohaemagglutinin (PHA) and about 80% of the thymocytes carrying the mature T3 marker were contained within the first two lightest fractions (Fr1 and Fr2). However, cells in Fr1 and in Fr2 were clearly different in terms of their interleukin requirement for mitogenesis, i.e. in the presence of interleukin-1 (IL-1), Fr1 thymocytes showed proliferative responses to PHA that were three to five times greater than those of the Fr2 cells, whereas in the presence of exogenous IL-2 both Fr1 and Fr2 cells had mitogenic responses of a similar magnitude. These differences could not be explained by accessory cell contamination or by different kinetics of the proliferative responses. Furthermore, in the presence of exogenous IL-1, Fr1 thymocytes showed a greater capacity for producing IL-2. In contrast, there was no difference in the expression of functional IL-2 receptors between the two fractions. It can be concluded that the mature thymocyte subpopulation contains at least two functionally distinct subsets, which differ in density, and that during intrathymic maturation the capacities to produce and to respond to IL-2 do not develop simultaneously. Although both the number and the binding characteristics of glucocorticoid (GC) receptor sites did not differ significantly between Fr1 and Fr2 thymocytes, dexamethasone was more effective in inhibiting the PHA-induced mitogenesis of Fr2 than of Fr1 cells. Thus, the GC sensitivity of T-cell mitogenesis is not directly correlated with receptor-related variables. In contrast with observations made on peripheral T cells, the inhibitory activity of GC on thymocyte mitogenesis was only partially reversed by the addition of exogenous IL-2. Thus, the inhibitory action of GC on thymocyte mitogenesis cannot be explained only by the steroid-induced inhibition of IL-1--IL-2 production; it must also be due to a GC-inhibitory effect on the IL-2-responsive cell proliferation.

Antigen-Presenting Cells↗
PubMed1986

Persistent generalized lymphadenopathy in Northeastern Italy: increased frequency of HLA-DR 5.

We undertake a study of Italian intravenous drug abusers and male homosexuals with the prolonged generalized lymphadenopathy syndrome (PGL). 75% of the subjects had the HLA-DR 5 antigen (relative risk 3.25). Only one patient was DR 2 positive. 14/20 subjects had anti-HTLV III antibodies and immunological malities were a rather constant finding.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Purified polyoma virus medium T antigen has tyrosine-specific protein kinase activity but no significant phosphatidylinositol kinase activity.

Medium T antigen, the transforming protein of polyoma virus, is associated with pp60c-src and strongly activates its tyrosine-specific protein kinase activity. We investigated whether the medium T-pp60c-src complex is also associated with an activity that phosphorylates the membrane phospholipid phosphatidylinositol, as shown for pp60v-src and p68v-ros, the transforming proteins of Rous sarcoma virus and avian sarcoma virus UR2, respectively. Medium T was purified by affinity chromatography from extracts of polyoma virus-infected mouse fibroblasts. It was bound to antibodies against a peptide corresponding to the carboxy terminus of medium T and released from the immune complex with an excess of the same peptide. In a second step, the partially purified medium T was bound to antibodies against another peptide corresponding to an internal region of medium T and released with excess peptide. Further purification was carried out with a monoclonal antibody against pp60c-src. Samples from each purification step were examined for protein kinase and phosphatidylinositol kinase activity. The highly purified preparations of the medium T-pp60c-src complex showed very low levels of phosphatidylinositol kinase activity, and no difference between medium T from transforming viruses and nontransforming hr-t mutants was detected. In contrast, protein kinase activity was associated with medium T purified from transforming viruses but not from hr-t mutants.

1-Phosphatidylinositol 4-Kinase↗
PubMed1986

Immunological abnormalities in intravenous drug abusers and relationship to the prolonged generalized lymphadenopathy syndrome in Italy.

The prolonged generalized lymphadenopathy syndrome (PGL) has been considered a prodromal condition to the Acquired immunodeficiency syndrome (AIDS), but the clinical, virological and immunological characteristics of patients who will develop AIDS are not known. We report on the immunological profile of intravenous drug abusers with or without PGL in Northeastern Italy. We found a reduction of lymphocyte-absolute numbers with reversal of the T4/T8 ratio and decreased Leu-11b+ cells. The response to mitogens and natural killer activity are compromised in PGL patients. Neutrophil function is reduced both in drug abusers with or without lymphadenopathy. The serological investigations revealed a high prevalence of antibodies against HTLV III and the Epstein-Barr viruses. The recognition of immune dysfunction in the intravenous drug abusers appears to be important since these patients develop AIDS and these abnormalities may precede AIDS.

AIDS-Related Complex↗
PubMed1986

Expression of 20 alpha-hydroxysteroid dehydrogenase activity in human lymphoid and non lymphoid cells.

Expression of 20-alpha-hydroxysteroid dehydrogenase (20 alpha-SDH), a putative T cell marker in the murine system, has been examined in human haematopoietic cells. Higher levels of enzymatic activity were expressed by human peripheral blood mononuclear cells (PBMC) in comparison with thymocytes. When PBMC were fractionated into T and non T cell subsets, the greatest values of 20 alpha-SDH activity were associated with the non T cell population. Cells from bone marrow exhibited lower levels of 20 alpha-SDH than PBMC and thymocytes. Both myeloid and lymphoid leukaemic cells expressed significant 20 alpha-SDH activity. In addition our data in U-937 and CM-S human cell lines indicate that cells belonging to the myelomonocytic precursor compartment constitutively expressed 20 alpha-SDH activity. Furthermore, this activity was less expressed when these cells were induced to monocyte-macrophage differentiation. In conclusion, our data in the human system indicate that 20 alpha-SDH should not be viewed as a lymphoid lineage-restricted marker enzyme.

20-Hydroxysteroid Dehydrogenases↗
PubMed1986

Estrogen binding sites in peripheral blood mononuclear cells and thymocytes from 2 myasthenia gravis patients.

In the present investigation the estrogen binding capacity of peripheral blood mononuclear cells (PBMC) and thymocytes from 2 young female Myasthenia Gravis (MG) patients has been studied. We found high levels of estrogen binding sites in both pre-thymectomy PBMC and lymphoid cells from the hyperplastic thymuses of the MG patients. A sucrose density gradient analysis revealed that the estrogen was binding to macromolecular species similar to those characterized in cytosols from classical estrogen target organs. A post-thymectomy time-dependent decrease of the estrogen binding capacity was also observed in PBMC, reaching levels similar to that of sex- and age-matched controls.

Adolescent↗
PubMed1985

Phase II trial of oral VP 16-213 (etoposide) in patients with advanced head and neck cancer.

We tested VP 16-213 in 16 patients with advanced head and neck cancer after conventional treatments. VP 16-213 was administered orally at the dosage of 100 mg/mq for 5 consecutive days every 3 weeks. No patient achieved an objective response. Toxicity was mild. VP 16-213 given at this dose and schedule revealed no activity in pretreated patients with head and neck cancer.

Aged↗
PubMed1985

Human T-cell receptor alpha-chain genes: location on chromosome 14.

The genes encoding the alpha chain of the human T-cell receptor have been mapped to chromosome 14, the chromosome on which the human immunoglobulin heavy chain locus resides. Thus, genes encoding two different classes of antigen receptor are present on the same chromosome. Furthermore, breaks involving chromosome 14 are frequently seen in tumors of T-cell origin. The potential relation of these chromosome abnormalities to alpha-chain genes is discussed.

Animals↗
PubMed1985

S-100 protein immunostaining in cells of dendritic morphology within reactive germinal centers by ABC immunoperoxidase method.

The "dendritic" and the "interdigitating" (IRC) reticulum cells are commonly reported to have different topographical distribution in the human lymphoid tissue and some peculiar cytochemical and immunohistochemical features. These include the detection of S-100 protein by PAP (peroxidase anti-peroxidase) method only in IRC located in the thymus-dependent areas. In 15 reactive lymphoid tissue specimens (11 lymph nodes, 3 tonsils, and 1 adenoid) the presence of S-100 protein was tested by ABC (avidin-biotin complex) immunoperoxidase method. IRC were constantly positive. Other positive cells were located within the follicular germinal centers; these immunostained cells appeared as a striking network composed of dendritic-shaped processes displaying a finely granular positivity for S-100 protein. It is suggested that by using this very sensitive technique, S-100 protein can also be detected in intrafollicular cells of dendritic morphology.

Avidin↗