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Biomedical subjects

L Bonomo

Publications and source records attributed to L Bonomo.

At least 199 records · Page 11Linked to original sources
PubMed1985

Monocyte chemotactic responsiveness triggered by Lymphocyte-Derived Chemotactic Factor in aged donors. Definitive report.

Monocyte chemotactic responsiveness triggered by autologous Lymphocyte-Derived Chemotactic Factor (LDCF) has been evaluated in a group of aged donors. LDCF obtained from Peripheral Blood Lymphocytes (PBL) supplemented with varying numbers of monocytes from aged donors gave a lower chemotactic response when compared to young donors. Moreover, when cell suspensions were pretreated with indomethacin (INDO) before LDCF production, an enhancement of LDCF-induced chemotaxis was observed in old individuals, this implying a prostaglandin-mediated suppression on LDCF release in the elderly. This lymphokine seems to be produced by T cells and, above all, OKT8+ cells, whose frequency is lower in aging. Interestingly, LDCF obtained from OKT8+ enriched cells supplemented with autologous monocytes induced in aged donors a chemotactic activity comparable to that observed in young subjects. These data suggest that the lower frequency of OKT8+ cells in the aging may play a key role in the impairment of LDCF-mediated monocyte chemotaxis.

Adolescent↗
PubMed1984

Diagnostic value of carcinoembryonic antigen (CEA) assay in pleural effusions.

Carcinoembryonic antigen (CEA) levels were evaluated by a direct radioimmunoassay in the effusion fluids and plasma samples from 107 patients with pleural effusions of unknown etiology. CEA levels higher than 20 ng/ml were detected in 55% of pleural effusions from patients with malignant disease: 40% of the patients in this group had values of plasmatic CEA lower than 20 ng/ml. With the only exception of 4 patients with empyema, CEA levels were uniformly lower than 20 ng/ml in the effusion fluid of patients with benign disease. Moreover, CEA levels higher than 20 ng/ml were observed in 81.2% of pleural effusions and 31.2% of plasma samples from patients with cytology positive for malignancy, whereas increased CEA levels were observed in 37.5% of effusion fluids and 33.3% of plasma samples from patients with malignant disease but negative cytology in the pleural effusion. CEA assay in the effusion fluid represents a useful tool of high specificity and good sensitivity to discriminate between benign and malignant etiology of pleural effusions.

Adult↗
PubMed1984

Non-specific immunity in aging: deficiency of monocyte and polymorphonuclear cell-mediated functions.

Peripheral blood monocytes obtained from 55 aged donors were evaluated for their chemotactic and phagocytic capacity. In the same subjects, polymorphonuclear cell-mediated functions were studied by chemotaxis, phagocytosis, nylon fiber adherence and nitroblue-tetrazolium reduction assay. Monocytes showed a normal chemotactic responsiveness to zymosan-activated serum, while the chemotactic activity induced by leukocyte-derived chemotactic factor and phagocytosis were rather depressed. A dramatic impairment of polymorphonuclear cell-mediated immune response was also observed. In fact, in spite of a normal nylon fiber adherence, chemotaxis, phagocytosis and nitroblue-tetrazolium reduction capacity were significantly depressed by the aging process. These data suggest that the deficiency of non-specific immunity may play an important role in the increased susceptibility to infections in aged donors.

Adult↗
PubMed1984

Relationship between immune system and gram-negative bacteria. II. Natural killer cytotoxicity of Salmonella minnesota Rb 345-unbound human peripheral blood lymphocytes.

Spontaneous binding of human peripheral blood lymphocytes (PBL) to bacteria represents a promising approach for the characterization of lymphocyte subsets mediating different functions. In the light of previous findings on the high degree of spontaneous adherence of S. minnesota Rb cells to PBL, we have evaluated the natural killer (NK) cytotoxicity of PBL subpopulations that fail to bind to Rb bacteria. The S. minnesota Rb-unbound cell fraction exhibits higher levels of cytotoxic capacity, which is related to a more elevated frequency of active NK cells, as determined in an agarose-single cell cytotoxic assay. Moreover, the cytotoxic activity of the unbound fraction is additionally boosted by interferon-alpha pretreatment. The effector cells bear Fc gamma receptors that are involved in NK cell lysis, because a decrease of NK activity is observed after immune complex modulation of the receptors. Finally, these cells, which display a high percentage (approximately 70%) of typical large granular lymphocyte morphology, express HNK-1, T10, T8, and M1 antigens, and to a lesser extent T3 and T4 antigens. These data indicate a selective enrichment of NK cells in the S. minnesota Rb-unbound fraction.

Adhesiveness↗
PubMed1984

In vitro effects of human lipoproteins on the immune system in healthy donors: inhibition of plaque forming cell generation and decreased frequency of NK cells.

The effects of human high density lipoproteins, low density lipoproteins and very low density lipoproteins on spontaneous plaque forming cell (PFC) generation have been evaluated in healthy donors. Additionally, natural killer (NK) cytotoxicity using either 51Cr release assay or agarose single cell system has been studied under identical experimental conditions. A significant inhibition of spontaneous PFC capacity was observed. Furthermore, lipoprotein (LP) pre-treatment led to a reduced frequency of cells mediating NK cytotoxic activity as shown by the decreased binding capacity, even if the killing function was per se not affected. Taken together, these results suggest an inhibitory role for human LP on certain immune functions, likely related to the imbalance of lymphocyte metabolic pathway.

Adult↗
PubMed1984

Relationship between immune system and gram negative bacteria. I. Spontaneous binding of smooth and rough Salmonella to human peripheral blood lymphocytes.

Over the past years many reports have emphasized that either Gram positive or Gram negative bacteria possess the ability to bind spontaneously to human peripheral blood lymphocytes (PBL). Here, bacterial binding to human PBL has been studied by using a smooth (S) Salmonella typhimurium LT-2 and two rough (R) mutants of Salmonella minnesota R 345 (Rb) and R 595 (Re), which possess specific deletions in their lipopolysaccharide (LPS) molecule. Our results provide evidence that all three bacterial strains spontaneously bind to PBL, even though Re and mostly Rb cells display the highest degree of adherence. The three major regions of LPS (O-polysaccharide chain, R core and lipid A) seem to be involved in the binding since adherence is specifically inhibited by pretreating PBL with S- or R-LPS extracted from homologous bacteria. Furthermore, using a panel of monoclonal antibodies to lymphocyte surface antigens, S- and R-Salmonella bacteria bind to T lymphocytes (preferentially T8+ cells), while few B cells are coated by bacteria. Additionally, bacterial binding is significantly reduced by trypsin pretreatment of PBL, this suggesting that proteins (or glycoproteins) of the PBL membrane are involved in the binding.

Antigens, Surface↗
PubMed1984

Effect of procetofen on serum lipids and apoproteins.

The effect of procetofen (fenofibrate) on lipids and apoproteins was studied in ten patients affected with familial type II-A and II-B hyperlipoproteinemia. Following stabilization with an isocaloric diet for 2 months, the patients were given 300 mg/day of procetofen for 3 months, then placebo for 1 month. Plasma cholesterol and triglycerides were decreased by 15% and 46%, respectively. Plasma apo B was lowered by 17%. The predominant decrease in lipids and apoproteins occurred in VLDL, whereas in HDL cholesterol increased significantly but not its major apoprotein, apo A-I. A mechanism of action involving increased catabolism of VLDL and reduced synthesis of LDL and VLDL is proposed.

Adult↗
PubMed1983

Abnormal T-cell functions in B-cell chronic lymphocytic leukemia do not imply T-lymphocyte involvement in the leukemic process: report of a case with demonstrated "polyclonality" of T lymphocytes.

In a patient with chronic lymphocytic leukemia (CLL), we previously demonstrated by glucose-6-phosphate isoenzyme analysis that monoclonality was restricted to B lymphocytes. Isolated T cells expressed both isoenzymes and, therefore, were apparently not involved in the leukemic process. This report presents results of a functional analysis of the patient's T cells. Cutaneous anergy to a battery of skin tests was correlated with abnormal proliferative responses of isolated T cells to phytohemagglutinin and concanavalin A. The addition of sufficient numbers of autologous adherent cells restored mitogen responses to nearly normal levels. However, the patient's T cells failed to provide help for differentiation of allogeneic B cells in response to pokeweed mitogen. These data suggest that altered cellular immunity in CLL is not necessarily due to intrinsic T cell abnormalities. Reduced numbers of circulating accessory cells and/or an imbalance in T-cell subsets related to the expansion of the leukemic B-cell clone may play a significant role.

B-Lymphocytes↗
PubMed1983

Circulating immune complexes in infected ventriculoatrial and ventriculoperitoneal shunts.

Distinguishing infected from noninfected ventriculoatrial (VA) or ventriculoperitoneal (VP) shunts is prognostically and therapeutically important. Eighty-seven serum samples from twenty-seven patients with VA or VP shunts were studied for the presence and quantification of circulating immune complexes. Eighty-three percent of the samples from infected shunts presented circulating immune complexes. Mean values of immune complexes in patients with infected shunts were significantly higher than in those without infection. In febrile, septicemic patients with few clinical symptoms, immune complexes were present, and their measurement in serial serum samples was a significant diagnostic aid. If circulating immune complex levels are not detectable, a shunt infection is less likely to be present.

Adult↗
PubMed1983

Phenotypic immaturity of T and B lymphocytes in cord blood of full-term normal neonates. Analysis of cell surface markers by using conventional techniques and monoclonal antibodies.

We examined mononuclear cell subsets in cord blood of normal newborns by surface marker analysis. The percentages of T lymphocytes (E-rosetting and T3+ cells) were lower in cord blood than in peripheral blood (PB) from adults, while the percentage and absolute number of T6+ cells were higher in cord blood. As the sum of T4+ and T8+ cells exceeded the values of E-rosetting lymphocytes in cord blood, we suggest that immature lymphocytes with the phenotype of 'common' thymocytes (T6+, T4+, T8+) are present in cord blood of full-term newborns. Higher percentage and absolute number of B lymphocytes were detected in cord blood. More than 50% of B cells in cord blood formed rosettes with mouse erythrocytes, a surface marker of functional immaturity. Finally, cells bearing receptors for IgG-Fc fragments or C3 and expressing Ia-like and M1 antigens were uniformly increased in cord blood, suggesting higher percentages of cells of the monocytic lineage.

Adult↗