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Biomedical subjects

C Bevilacqua

Publications and source records attributed to C Bevilacqua.

At least 19 recordsLinked to original sources
PubMed2007

Safety and immunogenicity of the RTS,S/AS02A candidate malaria vaccine in children aged 1-4 in Mozambique.

BACKGROUND: The development of a malaria vaccine remains a public health priority for sub-Saharan Africa. RTS,S/AS02A candidate malaria vaccine has been shown to be safe and immunogenic in previous studies in adults and staggered dose-escalation studies in children in The Gambia. However, genetic features and the intensity of malaria transmission may modify the safety and immune response of a vaccine. OBJECTIVE: We carried out a phase I, double-blind randomized controlled trial in 60 children aged 1-4 in Mozambique to evaluate the safety, reactogenicity and immunogenicity of the paediatric vaccine dose (fixed 25 microg RTS,S in 0.25 ml) of RTS,S/AS02A, prior to undertaking a planned larger phase IIb proof-of-concept of efficacy study in the same population. METHOD: Children were randomized to receive either RTS,S/AS02A or Engerix-B vaccine. Monitoring of safety and reactogenicity included detailed clinical and laboratory analyses and assessment of adverse events (AEs). RESULTS: The RTS,S/AS02A was found to be safe and well tolerated. Serious adverse events were balanced between both groups and none was related to vaccination. The frequency of adverse events reported with RTS, S/AS02A was comparable to previous studies in children. Grade 3 AEs were infrequent (one case of pain, one of fever in each group and some swelling greater than 20 mm in diameter), transient and resolved without sequelae. RTS,S/AS02A was highly immunogenic for anti-circumsporozoite protein antibody response and induced a strong anti-hepatitis-B surface antigen response.

Alanine Transaminase↗
PubMed2003

Intestinal epithelial exosomes carry MHC class II/peptides able to inform the immune system in mice.

BACKGROUND: Intestinal epithelial cells secrete exosome-like vesicles. The aim of this study was to characterise murine intestinal epithelial exosomes and to analyse their capacity to inform the immune system in vivo in mice. METHODS: Epithelial exosomes were obtained from the murine epithelial cell line MODE K incubated in the presence or absence of interferon gamma (IFN-gamma) together with pepsin/trypsin ovalbumin hydrolysate (hOVA) to mimic luminal digestion. Exosomes isolated from MODE K conditioned media (EXO-hOVA and EXO-hOVA-IFN) were characterised by western blot, peptide mapping, and mass spectrometry. They were injected intraperitoneally to C3H/HeN mice to test their immunocompetence. RESULTS: MODE K epithelial exosomes displayed major histocompatibility complex (MHC) class I and class II (upregulated by IFN-gamma) molecules and tetraspan proteins (CD9, CD81, CD82) potentially involved in the binding to target cells. A33 antigen, an Ig-like molecule highly specific for intestinal epithelial cells, was enriched in exosomes and was also found in mice mesenteric lymph nodes, suggesting exosome migration towards the gut associated lymphoid tissues. Intraperitoneal injection of EXO-hOVA or EXO-hOVA-IFN did not induce humoral or cellular tolerance to OVA in mice. In contrast, exosomes obtained after incubation with IFN-gamma (EXO-hOVA-IFN), bearing abundant MHC class II/OVA complexes, induced a specific humoral immune response. CONCLUSIONS: Epithelial exosomes are antigen presenting vesicles bearing MHC class II/peptide complexes that prime for an immunogenic rather than tolerogenic response in the context of a systemic challenge. In the intestine, both the mucosal microenvironment and local effector cells are probably key players in determining the outcome of the immune response to exosome derived epitopes.

Animals↗
PubMed2003

Expression of NGF, Trka and p75 in human cartilage.

Nerve growth factor (NGF) exerts its action through two types of receptor: high-affinity tyrosine kinase A receptor (trkA) and low-affinity p75 receptor. NGF has a neurotrophic role in central and peripheral nervous system development, but there is also clear evidence of its involvement in the developing skeleton. The aim of the present immunohistochemical study was to investigate the expression and distribution of NGF, trkA, and p75 in normal cartilaginous tissues from adult subjects: articular and meniscal cartilage of the knee, cartilage from the epiglottis, and intervertebral disc tissue. Detection of NGF mRNA was also performed by in situ hybridization. Immunoreaction for NGF and the two receptors in articular chondrocytes, chondrocyte-like cells of meniscus and annulus fibrosus, and chondrocytes of the epiglottis demonstrated that they are all expressed in hyaline, fibrous and elastic cartilaginous tissues, suggesting that they could be involved in cartilage physio-pathology.

Adult↗
PubMed2001

Cloricromene, a semi-synthetic coumarin derivative, inhibits tumor necrosis factor-alpha production at a pre-transcriptional level.

Cloricromene decreases myocardial infarct size after ischemic-reperfusion injury in vivo, and it has been suggested that this is due to inhibition of tumor necrosis factor-alpha (TNF-alpha). The purpose of this work was to characterize the mechanism of cloricromene-induced inhibition of TNF-alpha in rat macrophages. Cloricromene inhibited lipopolysaccharide-induced TNF-alpha release in a dose-dependent manner (IC(50)=5.9 +/- 0.8 microM). This was not due to cytotoxicity, as cloricromene was well tolerated up to 500 microM. Cloricromene inhibited lipopolysaccharide-induced expression of TNF-alpha mRNA, which suggests a pre-transcriptional effect. We then investigated the early signal transduction pathway triggered by lipopolysaccharide. The binding of lipopolysaccharide to its receptor CD14 activates protein kinase C and nuclear factor-kappaB (NF-kappaB). Cloricromene inhibited NF-kappaB activation in a dose-dependent manner, but affected protein kinase C translocation only slightly. We then established that cloricromene inhibited lipopolysaccharide-induced cellular oxidative activity, which is important for NF-kappaB activation. Our results show that cloricromene interferes with the early signal transduction pathway triggered by lipopolysaccharide.

Animals↗
PubMed2001

Anti-Fas-induced apoptosis in chondrocytes reduced by hyaluronan: evidence for CD44 and CD54 (intercellular adhesion molecule 1) invovement.

OBJECTIVE: To investigate the in vitro effect of therapeutic hyaluronan (HA) of 500-730 kd on anti-Fas-induced apoptosis of chondrocytes from osteoarthritis (OA) patients, and to assess its mechanism of action by analyzing the role of the 2 HA receptors, CD44 and CD54 (intercellular adhesion molecule 1 [ICAM-1]). METHODS: Chondrocytes isolated from human OA knee cartilage were cultured and the effect of HA on both spontaneous and anti-Fas-induced apoptosis was evaluated. Apoptosis was analyzed by JAM test (for quantitative analysis of fragmented DNA), cell death detection immunoassay (for quantitative analysis of oligonucleosome), TUNEL assay, and electron microscopy. Blocking experiments with anti-CD44 and anti-CD54 alone or in combination were performed to investigate the HA mechanism of action. RESULTS: Both quantitative tests demonstrated that anti-Fas significantly induced apoptosis of isolated OA chondrocytes. HA at 1,000 microg/ml significantly reduced the anti-Fas-induced apoptosis of chondrocytes but did not affect spontaneous chondrocyte apoptosis. These data were also confirmed by TUNEL staining and by electron microscopy morphologic evaluation. The antiapoptotic effects of HA on anti-FAS-induced chondrocyte apoptosis were significantly decreased by both anti-CD44 (mean +/- SD 57 +/- 12% inhibition) and anti-ICAM-1 (31 +/- 22% inhibition). The mixture of the 2 antibodies had an additive effect, since the rate of inhibition increased to 87 +/- 13%. CONCLUSION: These data demonstrate that 500-730-kd HA exerts an antiapoptotic effect on anti-FAS-induced chondrocyte apoptosis by binding its specific receptors (CD44 and ICAM-1). Furthermore, this HA fraction may be able to slow down chondrocyte apoptosis in OA by regulating the processes of cartilage matrix degradation.

Aged↗
PubMed2001

Autologous chondrocyte implantation: cells phenotype and proliferation analysis.

The phenotype and proliferation of human chondrocytes in culture were analyzed before they were implanted as autologous graft in cartilage lesions. During ten autologous chondrocyte implantations in articular cartilage lesions of the knee in ten patients, small amounts of cells to be implanted were collected and analyzed by morphology, cytochemistry (alcian blue, safranin-O), and immunocytochemistry (antibodies anti-S100 protein, anti-collagen types I and II, anti-chondroitin-S). In four cases the cells were also cultured for 3 weeks. At 1, 10, and 20 days of culture cells were incubated with 1 microCi/ml [3H]thymidine for proliferation analysis. In all cases the cells showed the morphological appearance of mature chondrocytes, stained positively for alcian blue and safranin-O, and revealed a strong immunoreaction for S-100 protein, type II collagen, and chondroitin-S but not for type I collagen. Radioisotope assay of chondrocyte proliferation at 1, 10, and 20 days of culture revealed a progressive increase in [3H]thymidine incorporation. These findings indicate that the cells before autologous implantation maintain their differentiated phenotype of mature chondrocytes and proliferate greatly. This analysis is an essential step preceding wider use of this treatment in humans. However, other biological aspects of the autologous chondrocyte graft remain to be elucidated.

Adolescent↗
PubMed2001

Goats' milk of defective alpha(s1)-casein genotype decreases intestinal and systemic sensitization to beta-lactoglobulin in guinea pigs.

Contradictory results have been reported on the use of goats' milk in cows' milk allergy. In this study the hypothesis was tested, using a guinea pig model of cows' milk allergy, that these discrepancies could be due to the high genetic polymorphism of goats' milk proteins. Forty guinea pigs were fed over a 20 d period with pelleted diets containing one of the following: soyabean proteins (group S), cows' milk proteins (group CM), goats' milk proteins with high (group GM1) or low (group GM2) alpha(s1)-casein content. Parenteral sensitization to GM1 and GM2 proteins as also assessed. The sensitization was measured (1) by systemic IgG1 antibodies directed against bovine or caprine beta-lactoglobulin (beta-lg), alpha-lactalbumin (alpha-la) and whole caseins, and (2) by intestinal anaphylaxis measured in vitro in Ussing chambers, by the rise in short-circuit current (delta Isc) in response to milk proteins. Guinea pigs fed on CM and GM1 developed high titres (> 1500) of anti-beta-lg IgG1, with an important cross reactivity between goat and cow beta-lg. However, in guinea pigs fed on GM2, anti-goat beta-lg IgG1 antibodies were significantly decreased compared with GM1 guinea pigs (mean IgG1 titres were 546 and 2046 respectively), and the intestinal anaphylaxis was significantly decreased (3.5+/-4.5 microA/cm2) compared with that observed in GM1 guinea pigs (8.3+/-7.6 microA/cm2). Animals receiving GM1 or GM2 proteins via the parenteral route developed a marked sensitization. These results suggest that the discrepancies observed in the use of goats milk in cows' milk allergy could be due, at least in part, to the high genetic polymorphism of goats' milk proteins.

Anaphylaxis↗
PubMed2001

Hyaluronan does not affect cytokine and chemokine expression in osteoarthritic chondrocytes and synoviocytes.

OBJECTIVE: Many studies have evidenced the clinical efficacy of hyaluronan (HA) in the treatment of osteoarthritis (OA). However, human and animal studies have described proinflammatory effects of HA on cells not involved in OA. We therefore investigated whether different molecular weight HA preparations can affect proinflammatory cytokine (IL1beta and TNFalpha) or chemokine (IL8, MCP-1 and RANTES) expression in human chondrocytes and synoviocytes isolated from OA patients. DESIGN: Human chondrocytes and synoviocytes were cultured in vitro in the presence or absence of three different purified HA pharmaceutical preparations (1x10(6) Kd, 5x10(5) Kd and 6.5x10(4) Kd) and assessed for the production of proinflammatory cytokines and chemokines and their mRNA expression. RESULTS: basal conditions, both chondrocytes and synoviocytes produce only MCP-1 and IL8, along with low quantities of IL1beta and TNFalpha, but not RANTES. IL8 production was generally about 100 times higher in chondrocytes than in synoviocytes, while MCP-1 was roughly twice as high in synoviocytes than in chondrocytes. At the mRNA level, expression of IL1beta, TNFalpha, IL8, MCP-1 and RANTES did not change in the presence of the three HA preparations either in synoviocytes or in chondrocytes with respect to basal condition. None of the three different HA preparations significantly affected production of IL8 or MCP-1. CONCLUSIONS: These data demonstrate that preparations of HA of the same origin but with different MWs do not induce proinflammatory cytokines and chemokines expressed by chondrocytes and synoviocytes that are either directly or indirectly involved in OA progression.

Adjuvants, Immunologic↗
PubMed2000

[Puntino and the injections of Popeye].

Subcutaneous injection of active principles must be performed through a short and thin needle and an insuline syringe (because of the few quantity of drug to administrate). In our Centre, to prevent preterm chronic anemia wc practice subcutaneous therapy with recombinant human erythropoietin. 300 UI three times a week, to all the newborns weighing < 1500 g at birth. Injections to the newborns are performed in correspondence of their gluteal and deltoid muscles, and in the outer part of their thigh. To prevent atrophy, it is important to change every time the site of Injection. For this goal, we have created the shape of a newborn, nained Puntino, and we have located 24 points on it. Each point has received a number between 0 and 23. During the treatment we have followed the guide of Puntino to locate each time the correct site of injection. Thanks to Puntino's aid, there were no cases of skin adverse reaction and atrophy, even in newborns weighing < 1000 g.

Anemia, Neonatal↗
PubMed1999

Differential inhibition of polymorphonuclear leucocyte functions by cloricromene.

Leucocytes play an essential role in the pathogenesis of ischaemia and reperfusion injury and inhibition of their adhesion and of mediator release can reduce vascular and tissue damage. Previous studies have shown that cloricromene modifies several granulocyte as well as monocyte/macrophage functions and it has been shown that cloricromene administration exerts a clear protective action in several experimental models of ischaemia. The present work describes new data on polymorphonuclear leukocyte (PMN) inhibition exerted by cloricromene and compares these observations with earlier ones. Human washed PMN and human whole blood (HWB) were studied in vitro upon stimulation with f-MLP in the presence of cytochalasin B, with opsonized zymosan and with a phorbol ester (PMA). Amongst free radicals, superoxide anions were chosen as index of oxidative burst. Phagocytosis and beta-glucuronidase, as lysosomal release indicators, were measured to characterize PMN function: cloricromene inhibited concentration-dependently all the parameters upon stimulation by each activator tested. Experiments performed in rabbit whole blood (RWB) showed that cloricromene inhibited free radical generation with IC50 values similar to those obtained in human whole blood. Comparing the action of cloricromene on human cells in different tests, we found that some parameters were more sensitive than others, even when the same stimulus was used. In particular, free radical generation was inhibited by cloricromene with IC50 values below 36 microM, while other functions, like lysosomal release and phagocytosis were inhibited with IC50 values over 100 microM. These data confirm that cloricromene exerts a notable inhibitory effect on PMN and may explain the activity of the compound, observed in vivo in several experimental models of ischaemia-reperfusion and shock.

Animals↗
PubMed1999

Effects of fentanyl on cellular immune functions in man.

In order to analyze the effects of the opioid agonist fentanyl on cells of the innate immune system, seven healthy individuals were treated intravenously with the opioid fentanyl and five subjects received a placebo. Respiratory burst of polymorphonuclear cells (PMNC) and phenotypes of peripheral blood lymphocytes (PBL) were analyzed from blood samples drawn before, 15 and 30 min after fentanyl or placebo application. In addition, in vitro effects of fentanyl on natural killer (NK) activity was assessed. Fentanyl administration affected neither superoxide production of PMNC nor circulating numbers of B-and T-lymphocytes. In contrast, NK cell (CD16+/CD56+) numbers significantly increased in response to fentanyl. However, no direct influence of fentanyl on NK cell function in vitro could be detected. These results suggest a transient effect of fentanyl on NK cell circulation which seemed to be centrally mediated rather than a direct effect of this opioid on NK cells.

Adult↗
PubMed1999

Cytogenetic study and FISH analysis in lymphocytes of systemic lupus erythematosus (SLE) and systemic sclerosis (SS) patients.

Systemic lupus erythematosus (SLE) and systemic sclerosis (SS) are autoimmune diseases characterized by the presence of antibodies against ubiquitous self antigens. The presence of clastogenic factors (CF) capable of inducing chromosome breakage has also been reported in the plasma of some patients. We aimed to assess basal frequency of cytogenetic damage in lymphocytes and presence of CF in the plasma of two groups of SLE and SS patients displaying a different antibody status (ACA-/Scl70+ or ACA+/Scl70-), using the micronucleus (MN) assay and FISH analysis with a pancentromeric DNA probe. As compared with controls, we found significantly higher MN frequencies in SS patients, but not in SLE patients. In addition, our data showed a significant prevalence of C-MN in SLE and ACA-/Scl70+ patients and of C + MN in ACA+/Scl70- patients. We observed a positive response in three out of the five CF experiments performed on plasma of SS patients. The three patients whose plasma caused MN induction were subtyped as ACA-/Scl70+, whereas the other subjects had ACAs. The same tests on six SLE patients gave negative results.

Adult↗
PubMed1999

Effects of fentanyl and low doses of alcohol on neuropsychological performance in healthy subjects.

The effects of the opioid fentanyl and low doses of alcohol on neuropsychological functions in healthy volunteers were measured. Twenty-four healthy male volunteers participated in this study. Two randomised placebo-controlled cross-over trials were conducted. In group 1, 6 subjects received fentanyl (0.2 microgram/kg body weight) in the order of fentanyl/placebo and 6 subjects in the order of placebo/fentanyl. Group 2 received alcohol in a similar procedure by continuous intravenous infusion, leading to a blood alcohol concentration (BAC) of 0.03%. Impairment was measured via different neuropsychological tests. The results indicate that fentanyl in concentrations commonly used in out-patient surgical procedures produces pronounced cognitive impairment (auditory reaction time, signal detection, sustained attention, recognition) in comparison to placebo. After application of low doses of alcohol (BAC 0.03%) only visual reaction time was impaired in comparison to placebo.

Adult↗
PubMed1999

In vitro effects of elastase on periosteum of long bones: an histochemical, immunohistochemical and morphometric study.

The aim of the study was to determine the in vitro effects of porcine pancreatic elastase on the periosteum of long bones and to what extent the effects are selective for the elastic fibres of the tissue. Twenty-eight new-born chicks' tibiae were incubated for 1 or 3 hours in different experimental conditions (PBS, 30 or 60 units (U)/ml of porcine pancreatic elastase) or immediately formalin fixed. The tibiae were then processed for histo-chemical (Verhoeff and van Gieson stain), immunohistochemical (anti-elastin antibody) and histomorphometric analysis. A decrease of periosteal elastic fibres in all the specimens incubated with elastase in comparison with non incubated specimens was evident. The effect of elastase was easily detectable even at the lower concentration (30 U/ml) and at the shorter time of incubation (1 h). The amount of elastic fibres decreased in accordance with the rise of enzyme levels and incubation time, while periosteal collagen fibre content was not substantially modified by elastase activity. Present data are a prerequisite to evaluate the in vitro and in vivo effects of experimental destruction of periosteal elastic fibres by elastase and to assess the role of these fibres in the growth process of long bones.

Animals↗
PubMed1998

Cryodamage of the vessel wall accelerates the development of atherosclerotic lesions in arterial vessels of Watanabe hyperlipidemic rabbits.

In the present study we developed an experimental model, resembling human atherosclerosis, by removing the endothelial layer in Watanabe heritable hyperlipidemic (WHHL) rabbits (10 months old) by application of cryodamage on the external surface of arterial vessels. In age-matched New Zealand white (NZW) rabbits, used as control, after two months following cryodamage, carotid artery and infrarenal segments of abdominal aorta did not show any particular change in the ultrastructure of vessel wall. In WHHL rabbits, two months after cryodamage, atherosclerotic lesions (fatty streaks and fibrous plaques) were observed in both arteries. Many lipid-laden endothelial cells, subendothelial foam cells and smooth muscle cells were found in cryodamaged areas. In some areas, the cap of plaques appeared to be thinned and ruptured. Increased number of collagen and elastic fibrils was also observed in atherosclerotic regions. We conclude that this simple technique on WHHL rabbits provides a model of atherosclerosis with a high degree of morphological similarity between the artificially-induced plaque and human atherosclerotic plaque.

Animals↗
PubMed1992

Protective role of heparin on in vitro functional aortic response in Watanabe heritable hyperlipidemic rabbits.

The effects of prolonged in vivo heparin treatment upon vasomotor responses and content of cholesterol and energy related compounds were studied in isolated thoracic and abdominal aortas from Watanabe heritable hyperlipidemic (WHHL) rabbits. Unfractionated heparin was administered subcutaneously (2 mg/kg twice a day) to 3-month-old WHHL rabbits for a period of 6 months. A group of WHHL rabbits was treated with saline solution and considered as control. Aortic cholesterol infiltration and serum cholesterol were not significantly decreased by the prolonged heparin treatment. In heparin-treated WHHL rabbits, the in vitro aortic endothelium-dependent relaxation produced by acetylcholine or calcimycin (A 23187) was greater than in saline-treated WHHL group. ATP-induced aorta relaxation (endothelium-dependent and endothelium-independent) did not vary significantly in the two groups of WHHL rabbits, even after mechanical removal of endothelium. Also the noradrenaline-induced aorta contraction did not vary between the two groups of WHHL rabbits. No significant variation in energy-related compounds (except for ADP) was found in the aortic arch. These results suggest that heparin produces a protective effect on aortic tissue by acting mainly at endothelial level.

Adenosine Triphosphate↗
PubMed1991

Acute carotid artery occlusive thrombosis and its pharmacological prevention in the rabbit.

A simple and reproducible method to induce an occlusive thrombus in rabbit carotid artery is reported. Rabbits were anesthetized and prepared to record arterial pressure, heart rate, and carotid blood flow. A critical stenosis of a damaged carotid artery was obtained using an external plastic cylinder. Complete occlusion occurred within 6 to 12 minutes, as measured by the decrease in blood flow. Both stenosis of the vessel and deliberate damage (clamping by surgical forceps) were found essential to occlusion. Occlusion was prevented by administration of heparin (200 IU/kg), tissue plasminogen activator (300 micrograms/kg), iloprost (10 micrograms/kg) or the synthetic thrombin inhibitor, FPRCH2Cl (0.5 mg/kg), while ASA (100 mg/kg) was uneffective. The procedure permits an easy and rapid evaluation of thrombus formation and of anti-thrombotic drugs affecting the hemostatic process.

Acute Disease↗