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Biomedical subjects

G Tridente

Publications and source records attributed to G Tridente.

At least 91 records · Page 5Linked to original sources

In vitro inhibition of histamine release from mouse mast cells and human basophils by an anthranilic acid derivative.

Optimal conditions for in vitro histamine release mediated either by Con A (3 micrograms/ml) or by Ionophore A23187 (1 microgram/ml), were established for mouse peritoneal mast cells and human normal basophils. In both systems N-5' exerts potent inhibiting effects on histamine release after short term (1-5 minutes) in vitro preincubation. At concentrations of 1mM for mouse mast cells and 3mM for normal human basophils, N-5' inhibits up to 95% Con A-induced histamine release and more than 50% ionophore-induced histamine release. Such in vitro effects are more potent than DSCG-mediated inhibition, under similar experimental conditions, and are resistant to challenge with exceeding doses of the two releasing agents, particularly in the Con A system. Interestingly, basophils with apparent normal morphology, from a CML patient, were resistant to both challenges.

Animals↗

Binding of sheep erythrocytes in chronic lymphocytic leukemias of B-cell origin.

Two patients with B chronic lymphocytic leukemia having leukemic cells that bind sheep red blood cells by different mechanisms are described. In the first case, rosette formation was mediated by the anti-sheep erythrocyte activity of a monoclonal surface IgMk, related to Forssman antigen. In the second, E-rosette formation was found to be independent of both surface immunoglobulins and the classic E-rosette receptor since the leukemic cells were recognized neither by the OKT-11 monoclonal antibody nor by other markers specific to T-cell lineage. Evaluation of these rare cases emphasizes that detection of surface immunoglobulins and spontaneous rosetting are not sufficient for the characterization of leukemic clones and raises some doubts concerning the use of available surface markers in the characterization of lymphoproliferative disorders.

Aged↗

Immunocompetence and dietary protein intake in early infancy.

Forty-one normal full-term infants were fed from birth, during the first 4.5 months of life, different diets based on two formulas similar in rough composition but basically different, the one being constituted only of cow milk protein and the other of soy protein. From each of the two formulas two different dilutions were prepared so that all diets supplied about 100 kcal/kg/day, but, respectively, 2.0 and 4.0 g/kg/day of cow milk protein and 2.0 and 5.0 g/kg/day of soy protein. After 4.5 months, growth in weight, length, and head circumference was normal and very similar in all infants. Gammaglobulin, immunoglobulin, transferrin, and some complement fractions (particularly C'3, C'1 INA, C'3 PA) were lower in infants receiving soy protein diets than in those receiving cow milk protein diets, and, within each type of diet, in those infants receiving lower amounts of protein. In particular, values of infants receiving 5.0 g/kg/day of soy protein were roughly comparable to those of infants receiving 2.0 g/kg/day of cow milk protein. B lymphocyte markers and reactivity did not show significant differences among the various groups. T lymphocyte markers and reactivity showed an impairment in soy protein diets (and in particular in 2.0 g/kg/day protein diets) with respect to cow milk diets. It was also observed that morbidity (mainly infections of upper respiratory tract) was higher in those infants who took soybean protein and in those who took lesser amount of protein.

B-Lymphocytes↗

Peripheral neuropathy associated with immunoglobulin disorders an immunological and ultrastructural study.

Light-, electron microscopic and immunopathological findings in a nerve biopsy of a patient with peripheral neuropathy associated with monoclonal gammopathy are reported. Loss of fibers, Wallerian-like degeneration and segmental demyelination were the most important features observed in light microscopy. In E.M. widening of the peripheral lamellae of myelin sheaths and occasional aspects of hypermyelination were seen. Immunoperoxidase study showed binding of IgM (k light chain) on the myelin sheath. The possible pathogenetic implications of these findings are discussed.

Aged↗

Thymic lymphocytes bear a surface antigen which cross-reacts with acetylcholine receptor.

Acetylcholine receptor (AChR) is a major antigen in the neuromuscular disease myasthenia gravis and it is clear today that the basic defect in this disease is brought about by an autoimmune attack on acetylcholine receptors at the neuromuscular junctions. The involvement of the thymus and its role in myasthenia have been widely investigated but are still poorly understood. A high incidence of thymic abnormalities is observed in patients with myasthenia and thymectomy is beneficial in many cases. Immunological studies have demonstrated the presence of humoral as well as cellular immune responses towards thymic tissues in myasthenic patients. There were also some reports that animals immunized with thymic extracts develop a partial defect in neuromuscular transmission. In spite of all these observations, the nature and origin of the association between the thymus and the neuromuscular junction in myasthenia gravis are still not known. We have previously demonstrated an immunological cross-reactivity, both humoral and cellular, between a thymic component and AChR; such a cross-reactivity could provide a molecular explanation for the involvement of the thymus in myasthenia gravis. In this study, we demonstrate, by using immunofluorescence and radioimmunological techniques, that thymic lymphocytes bear a surface antigen which binds specifically to antibodies against nicotinic AChR and is thus defined as an 'AChR-like' antigen. A preliminary report of this study has been published.

Animals↗

Carcinoembryonic antigen and cancer: a comparative study.

The sera of 212 patients with malignant and non-malignant diseases have been radioimmunoassayed for the presence of the carcinoembryonic antigen (CEA) using 3 different kits produced of Hoffman La Roche, Switzerland (RCK), BY Sorin-IRE, Italy and Belgium (SCK), and by the Istituto Sieroterapico Milanese, Italy (ICK). In the presence of endodermically-derived system carcinomas, the RCK gave more positive results (72.6%) than did the SCK (63.1%) or ICK (56.2%). With regard to other carcinomas, ICK (50.0%) and SCK (47.1%) gave better results than did RCK (30.6%). The results are discussed in terms of clinical usefulness of the CEA assay and as regards reproducibility, procedural advantages, and economical cost of each kit. It is concluded that the CEA assay cannot be used for the diagnosis of gastrointestinal cancers, although it is useful as a measure of "cancerosity" for prognostic purposes. In this sense the double antibody method employed by SCK and ICK is clinically more advantageous than is the perchloric acid extraction-zirconyl phosphate gel precipitation method of RCK.

Carcinoembryonic Antigen↗