Biomedical subjects
Publications and source records attributed to E Jirillo.
The Authors report the results concerning the control of the presence of bacterial endotoxins in parenteral drugs, blood products and immunological reagents and drugs, by means of Limulus amebocyte lysate test. All the data suggest that Limulus assay is a simple, rapid, sensitive test, mostly when it is correctly performed.
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Leukocyte inhibiting factor (LIF) release from lymphocytes cultures stimulated by bacterial lipopolysaccharides (LPS) has been investigated. Human lymphocytes cultured in the presence of E, coli or S. enteritidis LPS were able to release in the supernatants a substance with the following properties: a) same elution pattern of Bovine Serum Albumin (MW 69000) when filtered on Sephadex G-100; b) it migrates on disc electrophoresis a an albumin; c) not dialyzable; d) not cytotoxic; e) inhibition of polymorphonuclear cells migration in agarose plates; f) heat stability at 56 degrees C for 30'. This substance could be likely identified as LIF.
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Explore the source record for details and available documents.
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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.
Previous studies have demonstrated that benzodiazepines (BDZ) (e.g. diazepam) inhibit immune responsiveness. Since these drugs are largely used in psychiatric patients it is of great importance to verify the existence of different types of BDZ, which are not suppressive for the immune system. In this framework, our results indicate that alprazolam and triazolam, two triazolo-BDZ, do not modify in vitro phagocytosis and killing exerted by normal human polimorphonuclear cells and monocytes. On the contrary, they significantly enhance T lymphocyte-dependent antibacterial activity in normal donors. These data support the concept that triazolo-BDZ and, in particular, alprazolam may represent more appropriate drugs for the treatment of psychiatric patients (e.g. patients with phobic disorders and/or migraine) who display immunodeficits.
Polyamines are actively involved in immune processes and it is known that patients with cancer often exhibit immune deficits. Twenty-two patients with colorectal cancer were enrolled into this study, before starting conventional treatments. The relationship among the content of polyamines in red blood cells and phagocytosis and killing of monocytes and polymorphonuclear cells, and endotoxemia was investigated. The data show a negative correlation among levels of total polyamines and spermine and monocyte phagocytosis. Higher levels of spermine were present in patients with detectable circulating endotoxins. Our findings suggest a down-modulating effect of polyamines on the monocyte phagocytosis in untreated colorectal cancer patients; this effect could explain the presence of circulating endotoxins in cancer bearing patients.
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The Authors report the results concerning the control of presence of bacterial endotoxins in parenteral drugs, blood products and immunological materials, by means of Limulus amebocyte lysate test. All the data suggest that Limulus assay is a simple, rapid, specific and sensitive test for endotoxin detection, mostly when it is correctly performed.
The AA. have evaluated some parameters of leukocyte function (phagocytosis, killing and nitroblu tetrazolium NBT test) from premature children, comparing such activities with endotoxemia, detected by means of limulus assay. The results obtained point out that there is not relationship between impaired leukocyte functions and endotoxemia.
The authors of this paper attempt to indicate a feasible, easy-to-use and inexpensive instrument for daily assessing and monitoring of splenectomized subjects to see if they are immunocompromised. Skin tests which are considered easy and inexpensive, may be useful for immunological investigation if their effectiveness is considered equal to that of more difficult and expensive methods. They have also assessed the effectiveness of ST in the study of specific cell-mediated immunity in general and also in cases of delayed hypersensibility, comparatively to serum IFN gamma dosage. The latter is produced by Th1 lymphocytes and Natural Killer cells and is considered a reasonable indicator of cell-mediated immunity and Th1-related delayed hypersensibility. The results of this study confirm that ST is effective in 100% of all splenectomized patients compared to positivity of 60% for the compromise of the immunocompetent system revealed by serum IFN gamma dosage in the same sample of patients. In addition, the fundamental role of other cytokines was confirmed. These include IL-2 which is produced by Th1 lymphocytes and whose lack of results in splenectomized patients are immunocompromised. This is revealed not only by IFN gamma dosage but also by ST.
This paper attempts to explain if immunodepression in patients who had undergone a splenectomy may be due to altered balance between Th1-Th2 lymphocyte subpopulations, as shown in several studies on phagocyte and lymphocyte cells. This was achieved by dosing serum levels of IFNg, produced by Th1 lymphocytes and IL-4, produced by Th2 lymphocytes. Final analysis showed immunodepression in splenectomized patients but also emphasized that in 70% of all cases, there is functional damage of T-lymphocytes that continues for several years after the surgery involving both cellular and humoral immunity. Immunoglobulin dosage allows the increase of IgE to be seen in 50% of the splenectomized patients studied, all with allergic symptoms that appeared after the operation. The production of IgE is stimulated by Th2 lymphocytes. This leaves one to believe that splenectomy may favour the persistence of allergens in the blood, the appearance of allergic symptoms and the increase of IgE serum levels in patients with normal Th2 functioning and consequently, with normal or increased IL-4 serum levels.
The AA. have tested human sera from subjects with a clinical condition of delayed hypersensitivity (TBC and eczematous contact dermatitis) in order to detect factors affecting leukocyte migration in agarose plates. They found either inhibiting or stimulating factors of cellular migration. According to the most recent data about the same area they emphasyze a sort a regulatory mechanism of LIF or factors with activity LIF-like, due to antagonistic substances present in sera of their patients. Furthermore they suggest a list of factors able to inhibit or to enhance cellular migration.
BACKGROUND: Estrogens and polyamines seem to play an important role not only in cell growth and differentiation, but also in programmed cell death. The aim of the present study was to investigate the effects of 17beta-estradiol supplementation on apoptosis as well as on the polyamine content of an ER-positive human gastric cancer cell line (AGS). MATERIALS AND METHODS: Apoptosis was investigated by evaluating DNA fragmentation, using enzyme immunoassay and agarose gel electrophoresis and the phosphatidylserine exposure by flow cytometry analysis. Polyamine levels were evaluated by HPLC. RESULTS: 17Beta-estradiol gave rise to a marked pro-apoptotic effect at concentrations of 16 microM or higher compared to the control. Moreover, the hormone significantly reduced the contents of polyamines compared to control cells. The apoptotic effect of 17beta-estradiol was partially counteracted by exogenous spermine administration. CONCLUSION: 17Beta-estradiol administration induces apoptosis in AGS cells. Further, an increase in cell sensitivity to apoptosis due to a decline in the polyamine content may be suggested.
Patients with migraine without aura (MWA) display elevated amounts of Tumor Necrosis Factor (TNF)-alpha in their sera. In this study in 18 patients with MWA the in vivo effect of propranolol, a beta blocker agent, was evaluated with regard to the TNF serum levels before and after treatment. Results show that in 9 out 11 patients exaggerated serum concentrations of TNF reverted to normality after three months of therapy. Some hypotheses on the mechanisms of action of propranolol in terms of modulation of the immune response are formulated.