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Biomedical subjects

G Gasparotto

Publications and source records attributed to G Gasparotto.

At least 37 records · Page 2Linked to original sources

PHA-induced, antibody-mediated and spontaneous cellular cytotoxicity toward chicken red blood cells in solid carcinomas and glioblastomas.

In 29 bronchogenic, 22 esophageal carcinomas and 17 glioblastoma peripheral mononuclear cells cytotoxicity toward chicken red blood cells was studied under three different sets of conditions: spontaneously induced, PHA induced, or mediated by antibodies toward target cells lysis. Cultures were 48 hours. While the cytotoxicity induced by mitogen and that medicated by antibody are diminished when compared to the control groups, spontaneous cytotoxicity shows values significantly higher in all the tumoral forms examined. Kinetically this type of lysis shows an already increased release of isotope after 24 hours and a steady rise in the successive hours. After depletion of adherent cells the mononuclear elements lose most of their lytic power. This datum, which contrasts with the diminished spontaneous cytotoxicity toward tumoral cells frequently described in the course of neoplasm, underlines the heterogenicity of the element responsible for SCMC and the diverse effects that the disease provokes on cell function.

Animals↗

[Properties of human lymphocytes binding to mouse red blood cells].

Certain properties of the bond between lymphocytes and mouse red blood cells were studied. The turnover of the receptor on the lymphocytes of twelve healthy subjects was evaluated. After two hours of incubation in a medium devoid of additives the receptor is released and its resynthesis is completed in twenty-four hours. In experiments employing proteolytic enzymes inhibition of rosette formation is observed, whereas neuraminidase, under the same experimental conditions, significantly increases the number of rosette forming cells. The percentage of mouse rosette forming cells in nineteen patients affected with chronic lymphatic leukaemia was then evaluated (17 with type B and 2 with type T). On the basis of these cases and other recently published data, an ontogenetic explanation for the appearance of this receptor is proposed.

Animals↗

Immunobiology of primary CNS tumors in infancy and childhood. B- and T-cell dependent immunity and cytotoxicity and cell kinetic evaluation.

The authors report their experience on the immunological monitoring of children with posterior fossa medulloblastomas. The most important findings concerning humoral and cell-mediated immunity in this kind of patient are discussed. Among the main immunobiological pictures, the authors stress the remarkable failure of the T-cell dependent immune response, generally correlated to the degree of malignancy of the tumor, and the characteristic appearance of cells with natural cytotoxic activity, whose precise outlining is, at present, in progress. The B-cell dependent pool, mostly investigated through immunofluorescence studies, turned out to be very close to normal.

B-Lymphocytes↗

T cell immune function in newborn infants.

T cell immune function in 20 newborn infants was investigated. Previous studies showing increased spontaneous transformation and higher 3H-thymidine incorporation at lower PHA concentration in newborn infants were confirmed. A net increase in the number of active E rosette-forming lymphocytes and a slight decrease in the percentage of total E rosette-forming cells was also found. Our results suggest the presence of a subpopulation of activated T lymphocytes in the peripheral blood of newborns during the first days of life. Possible mechanisms of this activation are discussed.

Adult↗

Imbalance in T gamma and T mu lymphocyte subpopulations in patients with sarcoidosis.

The percentage and the absolute numbers of T lymphocytes Fc receptors for IgG and IgM (T gamma and T mu lymphocytes, respectively) were evaluated in fourteen patients with active sarcoidosis and in a group of controls. A marked increase in the percentage of T gamma cells and a net decrease of T mu cells were found. Although sarcoidosis patients present a T lymphopenia, the absolute number of T gamma lymphocytes was still increased whereas the T mu decrease was even more pronounced. The possible causes of this imbalance in view of the recent interpretations of T suppressor and T helper lymphocytes are discussed.

Adult↗

alpha-Mercaptopropionyl-glycine influence on the in vitro proliferative response of human lymphocytes.

The effect of alpha-mercaptopropinyl-glycine on the in vitro proliferative response of healthy subjects' lymphocytes was studied. Low doses of the drug enhanced spontaneous lymphocyte blastigenesis but had no effect on the PHA-induced blastic response. With increasing concentrations of alpha-mercaptopropionyl-glycine inhibition of 3H-thymidine incorporation was found in unstimulated as well as in PHA stimulated lymphocytes.

Amino Acids, Sulfur↗

Immunobiology of paediatric intracranial tumours. A preliminary report.

Preliminary findings in the evaluation of the immune response of children with primary neoplasms of the CNS, mainly medulloblastomas, are reported and discussed. A broad scheme for the monitoring of B- and T-cell-dependent immunity and of delayed hypersensitivity reactions in this type of patient is presented. The most important immunobiological findings are discussed. Special attention is given to the striking failure of the T-cell-dependent pool (currently identified by "active" RFC and blastigenesis tests) and to the remarkable decrease of hypersensitivity reactions (depressed skin-test response), both of which seem to be related to the degree of malignancy of the tumour. A very peculiar feature, i.e., the appearance of cells with natural cytotoxic activity, is dealt with in some detail. Our present knowledge concerning the immunobiology of primary CNS neoplasms is still very incomplete, but seems to suggest a possible role for immunotherapy in paediatric neurosurgery.

B-Lymphocytes↗

Immunological features in chronic lymphocytic leukaemia (CLL) of T cell origin.

Peripheral blood lymphocytes from a patient with chronic lymphocytic leukaemia of T cell origin were studied. The thymus derived nature of these lymphocytes was confirmed by surface markers, mitogen cultures, mixed lymphocyte reaction, cytotoxicity studies, and cytochemical stains. This case is notable for several clinical and laboratory findings. Among these, the benign clinical course, the reduced rate of serum immunoglobulins, the elevated number of active E rosettes, the increased PHA-induced response to low mitogen doses, the absence of PHA mediated cellular cytotoxicity, and the thy-like positivity to ANAE should be pointed out. Emphasis should be placed, however, on the loss of stimulatory ability in MLR. This last feature supports the hypothesis that these cells proliferate as a clone.

Aged↗

T mediated immunity in patients undergoing periodic hemodialysis.

Seventeen patients with well compensated chronic renal failure undergoing periodic hemodialysis were studied with regard to absolute number of T and B lymphocytes, spontaneous and PHA induced lymphocyte blastogenesis both with autologous and homologous compatible plasma. A normal lymphocyte count as well as a normal relative and absolute number of T and B lymphocytes was found in most cases. Spontaneous blastogenesis was normal. Lymphocyte response to PHA was reduced both with autologous and homologous plasma, but the depression was more relevant when autologous plasma was used in culture. The authors discuss these findings with respect to available data, particularly concerning inhibitory factors in uraemic plasma.

Adult↗

[Possible influence of plasma factors on lymphocyte blastigenesis and E rosette forming in rheumatoid arthritis (author's transl)].

The lymphocytes blastigenesis to PHA in culture with autologous or normal plasma, the formation of E rosettes and the presence of immunoglob-lins on the lymphocytes surface were evaluated in 51 patients with chronic primary polyarthritis. While the percentage of T and B cells was almost normal (52.1 +/- 2.1% and 18.1 +/- 2.1%, N.V. 55.6 +/- 2.0% and 16.2 +/- 0.8%), the blastigenesis was significantly reduced in cultures with a 25% autologous plasma (5399 +/- 709 cpm compared to 13,182 +/- 920 cpm of the normal standard) and returned towards normal values when it was replaced by the plasma of a normal subject (12,189 +/- 1081 cpm). The rheumatoid plasma was capable of reducing the blastigenesis in 11 normal subjects (7395 +/- 750 cpm). The preincubation for 90' of the lymphocytes of 14 controls in rheumatoid or autologous plasma induced a significant reduction in the formation of spontaneous rosettes (40.8 +/- 1.4 % and 56.2 +/- 1.7%). These results suggest that the reduced function of the T lymphocytes in this disease is due to plasma factors.

Arthritis, Rheumatoid↗

Active E rosette formation by human lymphoblasts.

The percentage of active and total E rosettes for lymphocytes cultured for 72 h both with and without phytohaemagglutinin (PHA) was evaluated in 20 normal subjects. A clear increase in the formation of active E rosettes by PHA-stimulated lymphocytes was demonstrated with respect to unstimulated lymphocytes. Our data gives further proof that the active E rosettes constitute a specific subpopulation of lymphocytes which represent functionally active T cells in the blood.

Adult↗