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Biomedical subjects

S Antonaci

Publications and source records attributed to S Antonaci.

At least 127 records · Page 7Linked to original sources
PubMed1982

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↗
PubMed1982

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↗
PubMed1981

Effect of methisoprinol on E-rosette formation by trypsin-treated lymphocytes.

Human lymphocytes lose the capacity to form E rosettes after trypsin treatment. This ability is partially restored, in normal conditions, by a prolonged incubation in fresh medium supplemented with FCS. By adding methisoprinol to trypsin-treated lymphocytes, it has been observed a significant recovery after 2 hours of incubation, without further enhancement up to 24 hours, when compared to the controls. These results imply that the drug effect is time-dependent and that methisoprinol acts likely by a metabolic pathway in the early resynthesis of E receptors on trypsin-treated lymphocytes.

Humans↗
PubMed1978

Cryoimmunoglobulinemia in four sisters.

Mixed-typed cryoproteins, consisting of IgG and IgM, were demonstrated in the sera of four sisters. While the IgG component was polyclonal in every instance, in two of them the IgM component was found to be monoclonal with type chi light chains. Clinical diagnoses included the purpura-weakness-arthralgias syndrome, posthepatitis cirrhosis, congestive heart failure and mitral stenosis. The cryocrit differed in the four sisters, ranging from 3 to 16%; in addition, rheumatoid factor activity was consistently associated with both washed cryoprecipitates and their isolated IgM components. Endomembraneous deposits of IgG and IgM were revealed by immunofluorescent studies of the renal biopsy specimen from one patient. A genetic abnormality, possibly of the autosomal recessive type, is suggested in this instance of familial cryoglobulinemia.

Aged↗
PubMed1975

Two-dimensional immunolectrophoresis as a diagnostic tool for heavy chain disease.

8 sera from patients with three types (gamma, alpha, mu) of heavy chain disease were tested by two-dimensional immunoelectrophoresis (Td. IEP) in order to assess the potential usefulness of such a technique as a routine diagnositc tool for heavy chain disease. Rocket immunoselection of the same sera was also performed by comparison. Characteristic, though not pathogomonic patterns were obtained by Td. IEP of the sera from patients with alpha chain disease. The main differential ciriteria by which heavy chain disease proteins could be differentiated from myeloma immunoglobulins were as follows: a) marked heterogeneity of the precipitin lines, ascribeable to the formation of polymers of different sizes; b) decreased sharpness, sometimes blurred delimitation, of the precipitin lines; c) frequent occurrence of spurs of the myeloma proteins over the deleted immunoglobulins in Kroll's tandeum variant, or between deleted immunoglobulins and small amounts of normal immunoglobulins present in the same serum. In our experience, rocket immunoselection does not show appreciable advantages as compared with Td. IEP.

Antibody Formation↗
PubMedDate not supplied

Lipoprotein-induced inhibition of plaque-forming cell generation and natural killer cell frequency in aged donors.

The in vitro effects of human high-density, low-density and very-low-density lipoproteins on plaque-forming cell generation and natural killer cytotoxicity were evaluated in 40 aged donors. Lipoprotein pretreatment led to a significant inhibition in plaque-forming cell capacity displayed by either peripheral blood mononuclear cells or purified lymphocytes. As far as natural killer cytotoxicity is concerned, such pretreatment decreased the number of natural killer cells bound to targets, while the lytic efficiency was unaffected in both 51Cr-release and agarose-single-cell cytotoxic assays. These data suggest a role for lipoproteins in the impairment of cell-mediated immunity in elderly individuals.

Aged↗
PubMedDate not supplied

Mononuclear cell subpopulations during normal pregnancy: I. Analysis of cell surface markers using conventional techniques and monoclonal antibodies.

Previous reports indicate depression of cellular immunity during pregnancy. In order to get a deeper insight into the immunoregulatory subsets of mononuclear cells in pregnant women, we analyzed the percentages of T and B lymphocytes, T cell subsets and cells expressing IgG-Fc and C3 receptors, and M1- and Ia-like antigens in venous blood samples from healthy women and pregnant women at different gestational ages and after delivery. Even if a trend toward a progressive decrease of T lymphocytes and T4+ helper subset was observed throughout pregnancy, along with a slight increase in the percentages of cells bearing C3 receptors, M1, and Ia-like antigens in the second trimester of gestation, analysis of variance of our data did not demonstrate statistical significance in the observed changes. Therefore we conclude that the pregnancy-induced suppression of maternal responsiveness towards alloantigens and/or mitogens is not reflected by significant changes in the distribution of circulating mononuclear cells and immunoregulatory T-lymphocyte subsets as defined by the currently available surface marker techniques.

Adolescent↗
PubMedDate not supplied

[Acute disseminated encephalomyelitis as initial clinical manifestation of common variable immunodeficiency. A case report].

Common variable immunodeficiency (CVID) is a primary immunodeficiency disease characterized by severe and recurrent infections which affect both lung and gastrointestinal systems. On the contrary, central nervous system involvement, related to virus infections, is an important, rare and usually fatal complication occurring in a later phase of the disease. Furthermore, CVID may predispose to a variety of autoimmune diseases. Here, we report the case of a 20 years old girl who developed acute disseminated encephalomyelitis as the first clinical feature in CVID. The infective agent was not determined and there was no history of recent vaccinations. CVID was diagnosed on the basis of the significant reduction of serum immunoglobulin concentration, in the absence of either diseases responsible for secondary immunodeficiency or functional and/or quantitative abnormalities of lymphocyte subsets, phagocytes and complement fractions. The treatment with high doses of native intravenous immunoglobulins (IVIG) combined with corticosteroids in the early phase led to a complete recovery with restitutio ad integrum. This case outlines the possible relationship between autoimmune diseases and infections in CVID, as suggested by the finding of either viral encephalitis in CVID patients and the well-known autoimmune pathogenesis of acute disseminated encephalomyelitis. In such a condition, the combination of IVIG and corticosteroids may offer considerable advantages in terms of therapeutical efficacy.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Altered expression of integrins and basement membrane proteins in malignant and pre-malignant lesions of oral mucosa.

Integrins are transmembrane receptors that regulate cell-cell and cell-extracellular matrix (ECM) contact. In epithelial tissues, they interact with ECM components of the basement membrane (BM) to maintain the homeostasis and the architecture of the tissue. This interaction controls several cell functions such as adhesion, migration, proliferation, differentiation, and therefore has a key role in cancer development and metastasis. We studied the expression of integrins and ECM components of the BM by immunohistochemistry in frozen specimens of malignant squamous cell carcinoma (SCC), pre-malignant lesions of the oral mucosa (leucoplakia) and oral lichen planus. In invasive SCC, we observed altered polarity and distribution of alpha2beta1, alpha6beta4 and alpha3beta1 integrins, whereas in the in situ carcinoma alpha6beta4 and alpha3beta1 patterns only were altered. Immunostaining for ECM components such as Laminin-1 (Ln-1), Ln-5, and Collagen IV (Coll IV) was discontinuous and interrupted in invasive SCC, whereas it was normal in the in situ carcinoma. In both pre-malignant lesions and lichen planus specimens, integrins were expressed in a polarized manner in the presence of a normal BM, whereas were abnormally distributed in those tissues with altered staining patterns of the ECM components. In conclusion, we suggest that abnormal re-distribution of alpha3beta1 and alpha6beta4 integrins and expression of ECM components such as Ln-5 could play an important role in SCC invasion and metastasis.

Antigens, Surface↗