Search PubMed⌕ Search

Biomedical subjects

F Rossano

Publications and source records attributed to F Rossano.

At least 37 records · Page 2Linked to original sources
PubMed1996

Rat seminal vesicle protein SV-IV and its transglutaminase-synthesized polyaminated derivative SPD2-SV-IV induce cytokine release from human resting lymphocytes and monocytes in vitro.

Micromolar amounts of SV-IV, one of the major proteins secreted from the rat seminal vesicle epithelium, induce in vitro a marked release of a variety of cytokines (interferon-gamma, tumor necrosis factor-alpha, interleukin 6, and granulocyte-monocyte colony-stimulating factor) from human resting peripheral blood mononuclear cells as well as from isolated resting lymphocytes and monocytes. This effect was found to be significantly higher when the spermidine adduct of SV-IV (Spd2-SV-IV), synthesized in vitro by the enzyme transglutaminase, was used instead of the native protein. Furthermore, the pretreatment of monocytes with transglutaminase caused an increase of the inducing effect of both native and modified SV-IV on the release of interleukin 6 from these cells. The inducing effect of these proteins on the cytokine release was markedly inhibited by actinomycin D and cycloheximide.

Animals↗
PubMed1996

Immunobiological activities of mould products: functional impairment of human monocytes exposed to aflatoxin B1.

In order to elucidate the effects upon the human immune system of aflatoxin B1 produced by the food-contaminating mould Aspergillus flavus, phagocytosis, microbicidal activity, superoxide production and intrinsic antiviral activity were studied in monocytes exposed to aflatoxin B1 for different times at concentrations ranging from 0.1 to 1 pg/ml. Phagocytosis and microbicidal activity were significantly impaired (p < 0.05) by aflatoxin B1 at doses as low as 0.1 pg/ml. However, pretreatment of monocytes with aflatoxin B1 did not modify intrinsic antiviral activity or superoxide production. These results confirmed data obtained from animals fed with mycotoxin-contaminated foods. The potential danger to human health of exposure to mycotoxins demonstrates the necessity for careful microbiological control of food.

Aflatoxin B1↗
PubMed1995

Survival to lipopolysaccharide, cytokine release and phagocyte functions in mice treated with different total parenteral nutrition regimens.

Effects on host defenses of Total Parenteral Nutrition (TPN) with long- (LCT) and medium-chain triglycerides (MCT) were studied. Survival to lipopolysaccharide (LPS) challenge, blood clearance of Escherichia coli, in vivo and in vitro production of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were investigated. In BALB/c mice, LCTs produced a 25% reduction in mortality, compared with controls. TPN performed with a LCT plus MCT mixture reduced mortality by 50%. Spasms appeared after 18 h and 12 h respectively in mice treated with LCT-MCT mixture or LCTs alone, respect to controls (8 h). The LCT-MCT mixture produced a 67% blood clearance of E. coli after 1 h, while the treatment with LCTs alone had no significant effects compared to controls (about 40%). The LCT-MCT mixture induced a 50% increase in chemiluminescence respect to controls. A 33% increase was observed in rats treated with LCTs alone. TNF-alpha serum levels after challenge with LPS were not modified by any of the triglycerides or their combinations. IL-6 increased by 43% with LCT-MCT mixture and by 39% with LCTs alone versus controls. After a 3 h in vitro treatment with LCTs, human monocytes were stimulated to release TNF-alpha at levels higher than those stimulated with the LCT-MCT mixture, and respect to controls. In contrast after 3 h the stimulation with LCT-MCT mixture induced a higher IL-6 release than controls and cells stimulated with LCTs alone, or with LPS.

Animals↗
PubMed1994

Immune enhancement by conditioning of senescent mice. Comparison of old and young mice in learning ability and in ability to increase natural killer cell activity and other host defense reactions in response to a conditioned stimulus.

It has been clearly demonstrated that immune responses may be conditioned in a manner similar to that of the classical Pavlovian experiments. Evidence of impaired immune function in aging has raised the question of whether psychological conditioning of an immune response can also be effective in old age. The knowledge that aged mice have decreased spleen cell natural killer (NK) activity and that NK cytotoxicity, at least in young mice, can be psychologically conditioned led us to explore in old mice the possibility of conditioning the response of NK cell activity using the odor of camphor as the conditioned stimulus (CS) and the injection of Poly I:C as the unconditioned stimulus (US). Young and old male mice were divided into five and six groups, respectively. They received the CS and/or the US in association (conditioning) trials (sessions 1-9). Mice were exposed to the camphor odor alone at 72 hours after the final association trial to observe the conditioning phenomenon (session 10). The group conditioned with Poly I:C and camphor and receiving the CS at session 10 showed statistically significant increases in spleen cell NK activity over those of the control groups that did not receive the CS treatment at session 10 (2.6- and 4.0-fold increase in young and old, respectively). Treatment with camphor odor alone had no effect on boosting NK cell activity. These findings demonstrate the possibility of conditioning immune responses in old age, offering a valuable tool for attenuating age-related immune deterioration in various species, including the human. In addition, these results again confirm highly significant immune enhancement by classical conditioning and extend previous findings from female mice to males as well.

Aging↗
PubMed1994

Properties of Yersinia enterocolitica porins: interference with biological functions of phagocytes, nitric oxide production and selective cytokine release.

We have extracted and purified Yersinia enterocolitica ATCC 9610 porins that have molecular weights of 36-38 kDa. They inhibited phagocytosis and phagosome-lysosome fusion (30%) in human monocytes and caused enhanced nitrite production. Preincubation of polymorphonuclear neutrophils with porins (1-10 micrograms/ml/10(6) cells) induced a reduction in chemotaxis, adherence to nylon wool and chemiluminescence. Human lymphomonocytes treated with Y. enterocolitica porins showed a distinctive cytokine profile. Interleukin-1 alpha, interleukin-6 and tumour necrosis factor alpha were released within 3-6 h, while interleukin-8, gamma interferon and granulocyte-macrophage colony stimulating factor were released after 18 h. Interleukin-3 and interleukin-4 were not detected at up to 48 h of incubation. In conclusion, these immunomodulating and histotropic properties may account for Y. enterocolitica infection and its sequelae.

Chemotaxis↗
PubMed1994

Immunobiological activities of Helicobacter pylori porins.

Studies were carried out on some biological activities of Helicobacter pylori porins in vitro. We extracted and purified a porin with an apparent molecular mass of 30 kDa. Human polymorphonuclear leukocytes preincubated with H. pylori porins showed a decrease of chemotaxis, of adherence to nylon wool, and of chemiluminescence. Used as chemotaxins in place of zymosan-activated serum or as chemotaxinogens in place of zymosan, the porins induced polymorphonuclear leukocyte migration. Human monocytes and lymphocytes cultivated in the presence of H. pylori porins released cytokines. Release of the various cytokines studied was obtained with differentiated kinetics and at various porin concentrations. Starting only 3 h after culture, tumor necrosis factor alpha is released quickly, reaching a peak at 18 h, at a porin concentration of 1 microgram/ml/10(6) cells. Interleukin-6 (IL-6) appears later, with a peak at 10 micrograms/ml/10(6) cells, while IL-8 is released after 6 h of culture, with a peak at 24 h, at a porin concentration of 10 micrograms/ml/10(6) cells, while IL-8 is released after 6 h of culture, with a peak at 24 h, at a porin concentration of 10 micrograms/ml/10(6) cells. Lymphocytes stimulated by H. pylori porins release gamma interferon after 18 h of culture at higher concentrations of porins (20 micrograms/ml/10(6) cells). Granulocyte macrophage colony-stimulating factor is released from 6 to 48 h at a concentration of 1 microgram/ml/10(6) cells, while both IL-3 and IL-4 are released after 18 h of culture at different porin concentrations (0.1 and 1 microgram/ml/10(6) cells, respectively). Our results lead us to think that during H. pylori infection, surface components, porins in particular, are able to induce a series of chain reactions ranging from the inflammatory to the immunological responses.

Chemotaxis, Leukocyte↗
PubMed1993

Outer-membrane porins from gram-negative bacteria stimulate platelet-activating-factor biosynthesis by cultured human endothelial cells.

Porins are a family of hydrophobic proteins located in the outer membrane of the cell wall in Gram-negative bacteria. The effect of porins on the biosynthesis of platelet-activating factor (PAF) by cultured human umbilical-cord-vein-derived endothelial cells (HUVEC) was investigated. The results demonstrate that porins were able to induce a dose-dependent synthesis of PAF in HUVEC. PAF, synthesized after stimulation with porins, was mainly cell associated and the synthesis peaked at 15 min, decreasing rapidly thereafter. Experiments with radiolabeled precursors demonstrated that PAF, a 1-O-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine, was synthesized via the remodeling pathway involving the acetylation of 1-O-alkyl-2-lyso-sn-glyceryl-3-phosphorylcholine (2-lysoPAF) generated from 1-O-alkyl-2-acyl-sn-glyceryl-3-phosphorylcholine by phospholipase-A2 activity. The activation of phospholipase A2 in HUVEC stimulated by porins was detected by observing the mobilization of [14C]arachidonic acid. In addition, the activity of acetyl-CoA:1-alkyl-sn-glycero-3-phosphorylcholine 2-O-acetyltransferase was transiently increased in porin-stimulated HUVEC and, after incubation with [3H]CoASAc or [3H]acetate, the [3H]acetyl group was incorporated into newly synthesized PAF. Porins, by forming transmembrane channels, induced a sustained influx of extracellular 45Ca2+ into the cytosol. The activation of PAF synthesis by porins depended on this influx rather than on intracellular calcium mobilization, since PAF synthesis did not occur in the absence of extracellular Ca2+.

Acetyltransferases↗
PubMed1993

Human monocytes and gingival fibroblasts release tumor necrosis factor-alpha, interleukin-1 alpha and interleukin-6 in response to particulate and soluble fractions of Prevotella melaninogenica and Fusobacterium nucleatum.

In this study we provide evidence that structural and soluble components of periodontopathogenic bacteria, such as Prevotella melaninogenica and Fusobacterium nucleatum, induce the release of cytokines in vitro known to cause in vivo necrotic inflammatory phenomena and bone resorption (tumor necrosis factor-alpha, interleukin-1 alpha and interleukin-6). Human monocytes and gingival fibroblasts were cultivated in vitro in the presence of both particulate and soluble bacterial fractions. A dose-dependent production of tumor necrosis factor-alpha by monocytes and gingival fibroblasts was observed in the presence of fractions of P. melaninogenica and F. nucleatum. Interleukin-1 alpha was produced in approximately the same quantities in the presence of soluble fractions of either P. melaninogenica or F. nucleatum, but in greater quantities in response to particulate fractions of P. melaninogenica. Monocytes released larger amounts of interleukin-1 alpha (about 3000 pg/ml) than gingival fibroblasts (about 1500 pg/ml). Interleukin-6 was released in greater quantities by monocytes in the presence of the pellet fraction of P. melaninogenica (about 5.5 ng/ml), but gingival fibroblasts released larger amounts of interleukin-6, especially in the presence of particulate and soluble components of F. nucleatum (about 12 ng/ml). The ability to induce the release of these cytokines notably increases the pathogenic potential of the bacteria involved in the damage of periodontal tissue.

Chemical Fractionation↗
PubMed1993

Imbalance between plasminogen activator and its inhibitors in thiol-induced acantholysis.

Pemphigus may be an idiopathic disease or a syndrome induced by drugs, mainly thiol drugs. Autoantibodies, always present in the idiopathic form but often lacking in the drug-induced one, may cause acantholysis by activating endogenous proteolytic enzymes. Pathogenesis of drug-induced pemphigus when antibodies are absent has not been elucidated yet. Extracts of skin tissues cultured for 4 days with penicillamine, captopril or thiopronine were assayed for the presence of plasminogen activator (PA) and plasminogen activator inhibitors (PAI) on agar fibrin plates. Moreover, uPA, tPA, and PAI-1 were identified in the extracts by immunoenzymatic assay. The results have shown progressively decreasing amounts of PAI-1 in penicillamine, thiopronine and captopril-cultured tissue extracts, respectively. This suggests that the acantholytic potential of thiol drugs is directly correlated to their capability of reducing PAI-1 in the epidermal cells leading to increased PA activity. This PA-PAI imbalance may be itself the cause of intraepidermal splitting.

Acantholysis↗
PubMed1992

Isolation and characterization of human embryonic osteoblasts.

Human osteoblasts were obtained by migration and proliferation of cells from embryonic membranous bone on glass fragments. Light and electron microscopy analyses revealed a typical osteoblast-like appearance with high protein synthesis activity. The cells showed high alkaline phosphatase activity that was associated with plasma membranes and matrix vesicles and was 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] responsive. In contrast to the adult osteoblasts, embryonic cells could not produce detectable levels of osteocalcin, not even in the presence of 1,25(OH)2D3. Osteoblasts grown in multilayers produced a thick extracellular matrix, mainly composed of type I collagen, that mineralized in the presence of 10 mM beta-glycerophosphate. Because of their intrinsic osteogenic capacity, embryonic osteoblasts represent a valuable model for studying the mineralization process in vitro. In addition, the embryonic origin of these cells renders them a precious experimental system for the elucidation of mechanisms at the basis of differentiation of osteoblastic lineage.

Alkaline Phosphatase↗
PubMed1992

Neutrophil function in rapidly progressive and adult periodontitis.

Our study focused on the functional characteristics of neutrophil leukocytes (PMN) in two different forms of periodontal disease:--Adult Periodontitis (AP) and Rapidly Progressive Periodontitis (RPP). Specifically neutrophil leukocytes in gingival fluid (GF) and in peripheral blood (PB) were studied. In our experimental studies we evaluated PMN hydrophobicity and adhering capacity, metabolic burst, chemotaxis response and N-formyl-L-methionyl-leucyl-phenylalanine (FMLP) receptor by using a chemotactic peptide labeled with 3H and by evaluating the binding on PMN. These functional characteristics were found markedly reduced in the RPP group, while in the AP group, they were comparable to those of a healthy control group. No difference between local (GF) and systemic (PB) values was detected.

Adolescent↗
PubMed1992

Porins and lipopolysaccharide stimulate platelet activating factor synthesis by human mesangial cells.

Porins, a family of hydrophobic proteins located in the outer membrane of the cell wall of gram-negative bacteria and lipopolysaccharide (LPS), were shown to stimulate the synthesis of platelet activating factor (PAF), a phospholipid mediator of inflammation and endotoxic shock, by cultured human glomerular mesangial cells (MC). The synthesis of PAF induced by porins was rapid (peak at 20 min) and independent either from contamination by LPS or from generation of an endotoxin-induced cytokine such as tumor necrosis factor (TNF) since it was not prevented by cycloheximide, an inhibitor of protein synthesis or anti-TNF blocking antibodies. LPS also stimulated PAF synthesis by MC. However, the kinetic of PAF synthesis induced by LPS was biphasic with an early and transient peak at 10 minutes and a second and sustained peak at three to six hours. This second peak required an intact protein synthesis and was prevented by anti-TNF antibodies, suggesting the dependency on LPS-induced synthesis of TNF. Experiments with labeled precursors demonstrated that in MC, either after stimulation with porins or LPS, PAF was synthesized via the remodeling pathway that involves acetylation of 1-0-alkyl-sn-glyceryl-3-phosphorylcholine (2-lyso-PAF) generated from 1-0-alkyl-2-acyl-sn-glyceryl-3-phosphorylcholine by phospholipase A2 (PLA2) activity. Porins and LPS, indeed, induced PLA2-dependent mobilization of [14C]-arachidonic acid that was inhibited by p-bromodiphenacylbromide (PBDB). PBDB, an inhibitor of PLA2, also blocked PAF synthesis by preventing the mobilization of 2-lyso-PAF, the substrate for PAF-specific acetyltransferase.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Outer Membrane Proteins↗
PubMed1992

Anesthetic agents induce human mononuclear leucocytes to release cytokines.

Studies were carried out on the ability of some anesthetic agents (Propofol, Dormicum, Ketalar and Penthotal) to induce the release of cytokines by human monocytes and lymphocytes in vitro. All anesthetic agents tested at hematic concentrations reached during anesthetic administration cause an increase in the production of Tumor necrosis factor (TNF) from human monocytes; the increase is 4-5 times greater than controls. The greatest Interleukin -1 alpha (IL-1 alpha) production increase was induced by Propofol. The release of Interleukin -6 (IL-6) is notably increased by Ketalar (about 10 times greater than controls). In the presence of different anesthetic agents, human lymphocytes release Interleukin -4 (IL-4) and Interferon gamma- (IFN-gamma). Penthotal and Ketalar increase IL-4 production which appears quite high compared to that obtained with Con A used as standard challenge. Propofol induce IL-4 release which is about the same as that seen with Con A. IFN-gamma is released in high quantities by lymphocytes treated with Propofol. Dormicum, Ketalar and Penthotal induce non-significant increase of IFN-gamma release. The results concern the choice of anesthetic, in relation to its action on host immune response. This aspect is particularly interesting in immunocompromised host.

Anesthetics↗
PubMed1988

Anti HSV-2 properties of amniotic fluid.

Some antiviral properties of amniotic fluid (AF) were studied. A close relationship between maternal blood and AF antiviral antibodies was seen. Substances other than antibodies which could have an effect on viruses were assumed to be present in AF. Using HSV2 as a model, we found a virus-neutralizing activity in 6 out of 7 specimens studied which does not appear to be related to antibodies.

Adult↗