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Biomedical subjects

L Bonomo

Publications and source records attributed to L Bonomo.

At least 217 records · Page 12Linked to original sources

Analysis of mononuclear cell subsets in pregnancies with intrauterine growth retardation. Evidence of chronic B-lymphocyte activation.

We have examined the mononuclear cell (MC) subpopulations of 5 pregnant women: Three of them had a previous history of IUGR, whereas two were primiparae and presented IUGR at the term of gestation. IUGR was confirmed after delivery in three women. The analysis of MC subsets was performed by rosetting and immunofluorescence techniques; both heterologous antisera specific for human immunoglobulins and monoclonal antibodies specific for T cell antigens and for M1 and Ia-like antigens were used. The three patients with IUGR confirmed at birth presented numbers of circulating lymphoid cells positive for cytoplasmic IgM, IgG and IgA and with morphologic features of plasmablasts or plasma cells at least tenfold higher than in normal pregnant women at the term of gestation. Our data suggest that chronic activation of the lymphoid system occurs in pregnant women with IUGR. Maternal abnormal reactivity to fetal antigens or to undiagnosed chronic infections may be likely explanations for this phenomenon. Further studies are clearly needed to clarify the relationship between B-lymphocyte activation and pregnancy and to examine the hypothesis of an altered balance of the immunoregulatory T lymphocyte subsets in patients with IUGR.

B-Lymphocytes↗

Humoral immune response in aged humans: suppressor effect of monocytes on spontaneous plaque forming cell generation.

In 50 old donors antibody synthesis has been detected using a protein A haemolytic plaque assay. Data provide evidence that the plaque forming cell (PFC) capacity of aged peripheral mononuclear cells (PBMC) is significantly depressed (0 . 01 greater than P greater than 0 . 001) in comparison to controls. Additionally, suppression is mediated by adherent cells, since monocyte depleted lymphocytes regain the ability of generating spontaneous plaques. The inhibitory effect of monocytes seems to be prostaglandin-dependent, since indomethacin pre-treated PBMC give rise to a normal number of plaques when compared to young mononuclear cells.

Adult↗

Characterization of the circulating immune complexes in acute and chronic liver diseases.

The composition of immune complexes (IC) found in 28 patients with HBsAg positive and negative acute and chronic hepatitis was analysed. Components were defined in PEG-precipitated material isolated by preparative ultracentrifugation on linear sucrose density gradients and analysed by the Ouchterlony plate technique and by the radioimmunoassay of hepatitis B virus markers. Sedimentation rate ranged from 8 to 19s in the serum of patients with chronic hepatitis, whereas heavier IC (greater than 19s) were present in the active phase of the disease. The participation of hepatitis B virus in acute hepatitis was shown by the presence of its antigens. In contrast, a low incidence of vital components was seen in IC of chronic active hepatitis and liver cirrhosis. Thus, other causes must contribute to the formation of IC in chronic liver disease.

Acute Disease↗

Platelet satellitism to basophils in a patient with chronic myelocytic leukaemia.

Platelet satellitism to basophil granulocytes was observed in a patient with chronic myelocytic leukaemia. This phenomenon occurred with peripheral basophil cells obtained from venous blood anticoagulated with EDTA. Previous reports have demonstrated platelet satellitism to polymorphonuclear neutrophils and monocytes but not to other types of white blood cells. The cause of the platelet satellitism in this CML case remains unclear. It is suggested that this rare phenomenon should be considered in evaluating the platelet number in CML.

Aged↗

In vitro modulation of cell-mediated immunity by prostaglandin E2. I. Enhancing-inhibitory effects on antibody-dependent cellular cytotoxicity.

The modulating effects of Prostaglandin E2, solubilized in medium, were observed in the antibody-dependent cytotoxic system. The pretreatment of effector cells with PGE2 up to 5 hours increased significantly the cytotoxic activity. The enhancement was distributed in both Non-T and T lymphocyte fractions suggesting a more pronounced activation of K cells. The effect was abrogated by pretreating lymphocyte suspensions with Indomethacin before exposure to prostaglandin. On the other hand, the addition of PGE2 during the test led to an inhibition of the cytotoxic capacity. Taken together, these results imply either a relationship between endogenously produced PGE2 and the concentration of exogenous PGE2 or the influence of PGE2 on microenvironment (i. e. exchange of calcium and magnesium through the cell membrane) during the cytolytic phenomenon.

Antibody-Dependent Cell Cytotoxicity↗

In vitro modulation of cell-mediated immunity by prostaglandin E2. II. Enhancement of spontaneous plaque-forming cell generation.

The effect of the pretreatment of human peripheral blood lymphocytes by Prostaglandin E2 (dissolved in medium) on the spontaneous Plaque-Forming Cell generation has been evaluated. A significant enhancement of immunoglobulin production, markedly increased by the addition of further PGE2 to the pretreated cells, has been demonstrated. Experiments carried out with indomethacin have shown an inhibition of plaque formation, thus indicating that the content of endogenous prostaglandin E2 may play an important role in the enhancement of antibody synthesis, previously described. Results obtained with populations of rosetting and non-rosetting lymphocytes pointed out that non-rosetting cells are exclusively responsive to prostaglandin treatment.

Dinoprostone↗

Behaviour of immune complexes and the complement system in normal pregnancy and pre-eclampsia.

A quantitative study of the circulating immune complexes (IC) was carried out on women during normal pregnancy (286) and the post-partum period (20) and women with pre-eclampsia (30). Furthermore, the behaviour of the complement (C) system was followed. Results showed that IC were low in the first trimester of normal pregnancy (25.3%) and decreased in the following trimesters, whereas they were always present in pre-eclampsia. A very significant difference (p less than 0.0001) was seen when we compared the incidence of IC in normal pregnancy at the third trimester and the pre-eclamptic patients. The follow-up study of the IC, carried out on 4 pre-eclamptic women, showed an increase in the IC levels associated with the exacerbation of the pre-eclamptic picture and a decrease after delivery. The study of complement in normal pregnancy showed a decrease in C1-INH, C1s and C1q, whereas C3, C5, C9 and the properdin factor B increased during the following weeks of gestation; CH50 did not vary excepting during the 1st trimester. In the puerperium all values increased. There was no significant difference between the serum levels of the C components in the 3rd trimester of normal pregnancy and pre-eclampsia. High levels of C3d were observed in normal pregnancy at the 3rd trimester and in pre-eclampsia. The study of this split product of C3 showed that there is activation of the C system, but, since the synthesis of the C components is increased, activation could be masked. Alloantibodies and circulating IC could be the factors responsible for this activation in normal pregnancy and in pre-eclampsia, respectively.

Adult↗

Defective monocyte chemotactic responsiveness in patients with multiple myeloma and benign monoclonal gammapathy.

The chemotactic responsiveness of peripheral blood monocytes was evaluated in three groups of subjects: 32 patients with multiple myeloma, 27 subjects with benign monoclonal gammapathy, and 64 normal controls. Monocyte chemotactic responsiveness was significantly depressed both in multiple myeloma patients (P less than 0.001) and in subjects with benign monoclonal gammapathy (P less than 0.001) as compared to that found in the control population. Although the results of chemotactic response obtained in multiple myeloma and in benign monoclonal gammapathy patients were largely overlapping, a significant difference was also found between the mean values of the two groups (P les than 0.025). The results support the hypothesis that myelomatosis, similarly to other neoplasms, may affect monocyte migratory activity thus hindering immunologically mediated destruction of tumour cells.

Chemotaxis, Leukocyte↗

Activation of the alternative complement pathway by unidentified substances in human glomerulonephritis.

Activation of the alternative complement pathway (AP) has been investigated in 79 serial serum samples obtained from 28 patients which had different types of glomerulonephritis. Serum factors activating the AP of the complement system have been detected in 12 patients with various forms of glomerulonephritis. Immune complexes (IC), levels of complement components of the classical and the alternative pathways and cobra venom factor activity were measured. Serum specimens were subcategorized as 2 study populations: (i) patients with serum factors activating AP and (ii) patients with both serum activators and IC. Although CoVF-AH50, properdin factor B and C3 concentrations were comparably depressed in these two groups, the levels of Clq and C4 were very low only in patients with circulating IC. These data were highly suggestive of AP activation due to serum factor. In contrast the patients also showing circulating IC had activation of both pathways. The presence of these factors suggests that renal damage can be determined by other immunological stimuli.

Antigen-Antibody Complex↗