Biomedical subjects
Publications and source records attributed to I Rossi.
Based on general concepts relating to risk perception, the authors summarize in this article today's knowledge of smoking risk perception. A pluridisciplinary approach (general internal medicine, public health and anthropology) allows an improved understanding of its complexity, its utility in every day clinical practice and of the questions still pending around its use and evaluation in research projects.
In this study the anti-angiogenic action of a novel non-peptide RGDS-analog named RAM was tested in vitro and in vivo. RAM inhibited FGF-2-induced chemotaxis by 80% in an adhesion-independent way. Further, it induced HUVEC-apoptosis in collagen-seeded HUVEC, indicating that such pro-apoptotic effect was adhesion-independent. In vivo studies revealed that RAM inhibited FGF-2 induced angiogenesis by 60% in the mouse Matrigel-assay and in the chicken-egg chorion-allantoic membrane assay. Finally, RAM was markedly more stable in serum as compared to the template RGDS and after 24 h incubation in 100% serum was significantly more active than RGDS. Taken together these results show that RAM exerts anti-chemotactic and pro-apoptotic effects, by an unexpected adhesion-independent mechanism, as we have recently shown for the template RGDS molecule [Blood 103 (2004) 4180], and has in vivo relevant anti-angiogenic properties, with marked stability in serum; therefore, RAM represents a novel promising anti-angiogenic molecule.
PURPOSE: The aim of this study was to define the interest of sentinel lymph node biopsy (SLNB) for the staging of ductal carcinoma in situ (DCIS) and DCIS with micro-invasion (DCISM) in patients with breast carcinoma. MATERIAL AND METHODS: From June 1999 to December 2002 we listed, in a retrospective study, 52 patients treated surgically for a DCIS or a DCISM. All except one had an histology before surgery, and all had SLNB. Intraoperative imprint cytology of the sentinel lymph node (SLN) was performed then there were analysed by staining with hematoxylin-eosin. Patients with positive SLN underwent complete axillary dissection. RESULTS: It was removed an average of three SLNs by patient (extreme 1 to 6). Metastases in the SLN were detected in four (7,7%) of the 52 patients, including three cases had only micrometastases in the SLN. In the four patients treated with complete axillary dissection, the SLN were the only positives nodes. CONCLUSION: The SLNB for DCIS and DCISM increases the involvement rate of lymph node. Because of the widespread for early detection of breast cancer, it is noted a regular increase in the rate of DCIS. Even if the attitude to be had towards the lymph node metastases in these cases is not yet well defined, and so only 2% of the patients approximately die of this pathology, it is interesting because of increase in absolute value of mortality, to try to improve the prognosis criteria to modify the treatment of this pathology.
Transgenic Balb/c mice expressing the transforming rat HER-2/neu oncogene develop early and multifocal mammary carcinomas. Within the first 5 months of life the tissue-specific expression of HER-2/neu causes a progression in all their 10 mammary glands from atypical hyperplasia to invasive carcinoma. It was previously observed that chronic administration of interleukin (IL)-12 increased tumor latency, but every mouse eventually succumbed to multiple carcinomas. A significant improvement in tumor prevention was sought by administering allogeneic mammary carcinoma cells expressing HER-2/neu combined with systemic IL-12. This treatment reduced tumor incidence by 90% and more than doubled mouse lifetime. For the maximum prevention p185(neu) antigen must be expressed by allogeneic cells. IL-12 treatment strongly increased the cell vaccine efficacy. The mammary glands of mice receiving the combined treatment displayed a markedly reduced epithelial cell proliferation, angiogenesis, and HER-2/neu expression, while the few hyperplastic foci were heavily infiltrated by granulocytes, macrophages, and CD8(+) lymphocytes. Specific anti-HER-2/neu antibodies were produced and a nonpolarized activation of CD4(+) and CD8(+) cells secreting IL-4 and interferon (IFN)-gamma were evident. A central role for IFN-gamma in the preventive effect was proven by the lack of efficacy of vaccination in IFN-gamma gene knockout HER-2/neu transgenic Balb/c mice. A possible requirement for IFN-gamma is related to its effect on antibody production, in particular on IgG2a and IgG2b subclasses, that were not induced in IFN-gamma knockout HER-2/neu mice. In conclusion, our data show that an allogeneic HER-2/neu-expressing cell vaccine combined with IL-12 systemic treatment can prevent the onset of genetically determined tumors.
The expression and biological function of Nerve Growth Factor (NGF) receptors was studied in a panel of rhabdomyosarcoma cell lines derived from embryonal and alveolar histotype. All the cell lines expressed both the high affinity receptor TrkA and the low affinity receptor p75(NTR). Treatment with exogenous NGF did not considerably alter rhabdomyosarcoma cell growth or differentiation, but significantly inhibited spontaneous apoptosis as well as apoptosis, and induced by serum starvation or apoptosis induced by treatment with cycloheximide (CHX). Rhabdomyosarcoma cell lines expressed NGF and other neurotrophins and trace amounts of NGF protein were found in the supernatants of rhabdomyosarcoma cell cultures. Blocking the putative autocrine loop with an anti-NGF antibody resulted in an increase in apoptosis compared with control cultures. These data suggest that the simultaneous presence of both high and low affinity NGF receptors engaged by endogenous or exogenous NGF might contribute to the escape from apoptosis exhibited by the rhabdomyosarcoma cells.
TS/A spontaneous mouse mammary adenocarcinoma cells were engineered to release interferon-gamma (IFN-gamma), a Th1 cytokine (TS/A-IFNgamma) and interleukin-13 (IL-13), a Th2 cytokine (TS/A-IL13). Mice bearing lung micrometastases induced by parental TS/A cells received repeated subcutaneous vaccinations with TS/A-IFN-gamma admixed with TS/A-IL13 engineered cells. This combined treatment cured up to 75% of mice, whereas vaccinations with either TS/A-IFNgamma or TS/A-IL13 alone cured only 20-40% of mice. Combined TS/A-IL13 and TS/A-IFNgamma therapeutic vaccinations elicited a reactive infiltrate of CD4+ and CD8+ lymphocytes in lung metastases and an increased production of IFN-gamma in the spleen and lung, suggesting a shift of the immune response toward the Th1 type. The type of infiltrating cells along with the lack of efficacy in T cell-deficient mice point to a major role of T cells. In conclusion, no antagonism but a synergistic and effective definitive cure stems from the combined vaccination with tumor cells engineered to release a Th1 and a Th2 cytokine.
AIM: To establish the value of alanine aminotransferase normalization and hepatitis C virus-RNA clearance as predictors of sustained virological response in naïve and relapser chronic hepatitis C patients on mono or combination therapy. METHODS: A total of 282 hepatitis C patients were studied: 98 naïves on interferon, and 64 naïves and 75 relapsers on interferon plus oral ribavirin; 45 patients were excluded. Drugs were administered at standard doses for 12 months. Alanine aminotransferase and hepatitis C virus-RNA were determined at baseline and at weeks 4, 12, 24, 48, and at 72 and 96 weeks after completion of therapy. RESULTS: The rate of sustained response was greater (P < 0.05) in naïves and relapsers on combination therapy (33% and 48%, respectively) than in naïves on interferon alone (16%). Hepatitis C virus-RNA significantly decreased from baseline by week 4 in naïves on interferon and relapsers on combination therapy and by week 12 in naïves on combination therapy. Alanine aminotransferase levels paralleled viremic load in naïves on interferon, yet in patients on combination therapy, alanine aminotransferase normalized independently of the virological response. During treatment, the main factor associated with sustained response was hepatitis C virus-RNA clearance by week 4 in naïves on interferon and relapsers on combination therapy, and by week 24 in naïves on combination therapy. CONCLUSION: Clearance of viraemia constitutes the best predictor of a sustained response to therapy, but needs to be measured at patient-specific times.
Ethanol (1-20% vol/vol) caused a dose-dependent reduction in the basal rate of acid formation in isolated rabbit gastric glands with a calculated EC(50) value of 4.5 +/- 0.2%. Ethanol also reduced ATP levels in isolated gastric glands and in cultured parietal cells (EC(50): 8.8 +/- 0.4% and 8.5 +/- 0.2%, respectively) and decreased both basal and forskolin-stimulated cAMP levels. In studies carried out in gastric gland microsomes, ethanol inhibited the hydrolytic activity of H+-K+-ATPase(EC(50): 8.5 +/- 0.6%), increased passive proton permeability (EC(50): 7.9%), and reduced H+-K+-ATPase-dependent proton transport (EC(50): 3%). Our results show that the inhibition of gastric acid secretion observed at low concentrations of ethanol (< or =5%) is mainly caused by the specific impairment of H+-K+-ATPase-dependent proton transport across cell membranes rather than inhibition of the hydrolytic activity of H+-K+-ATPase, reduction in the cellular content of ATP, or increase in the passive permeability of membranes to protons, although these changes, in combination, must be relevant at concentrations of ethanol > or =7%.
Transgenic FVB-NeuN mice (N202) bearing the rat neu protooncogene driven by the mouse mammary tumor virus promoter/enhancer develop focal mammary carcinomas overexpressing the neu-encoded p185(neu) protein. In vitro expression of p185(neu) among mammary carcinoma cultures was heterogeneous, and we could establish some cell lines and clones displaying a complete loss of p185(neu) expression, along with others with very high p185(neu) protein level. Upon in vivo injection, p185(neu)-positive cells gave rise to fast-growing tumors with a short latency, while p185(neu)-negative cells required a very long latency time, and the resulting tumors were invariably p185(neu)-positive. The lower growth ability of p185(neu)-negative cells in vivo was also confirmed in athymic nude mice. In vitro, analysis of anchorage-independent growth in soft agar revealed colony formation from p185(neu)-positive but not p185(neu)-negative cells. The direct involvement of p185(neu) in clonogenicity was demonstrated by the inhibition of p185(neu)-positive colony growth in soft agar in the presence of an anti-p185(neu) monoclonal antibody. By contrast, a higher level of anchorage-dependent clonogenic growth and proliferation was observed in p185(neu)-negative cells as compared to p185(neu)-positive cells, thus explaining the relative ease with which p185(neu)-negative cell lines and clones were established in vitro. Together, the results indicate that p185(neu) expression can lead to tumor formation and metastasis through the modification of intrinsic properties of cells related to anchorage-independent growth ability rather than to proliferation or host-dependent mechanisms.
Five human rhabdomyosarcoma cell lines were used to investigate the surface expression of HER/erbB receptors, particularly of HER-2, HER-3 and HER-4, by flow cytometry. HER-2 was expressed in 3/5 rhabdomyosarcoma cell lines. HER-3 was expressed in all rhabdomyosarcoma cell lines. None of the rhabdomyosarcoma cell lines investigated showed HER-4 surface expression. To study the biological activity of HER/erbB receptors in rhabdomyosarcomas, cells were cultured in the presence of glial growth factor 2 (GGF-2), a specific ligand of HER-3 that is able to stimulate myogenesis in normal myoblasts. In 3 of 3 human rhabdomyosarcoma cell lines positive for both HER-2 and HER-3 receptors, the treatment with GGF-2 induced a significant increase in myogenic differentiation.
A comparative study of the gas-phase reactions of NO2+ with acetylene and ethylene was performed by using FT-ICR, MIKE, CAD, and NfR/ CA mass spectrometric techniques, in conjunction with ab initio calculations at the MP2/6-31+G* level of theory. Both reactions proceed according to the same mechanism, that is, 1,3-dipolar cycloaddition, but yield products of different stability. The C2H2NO2+ adduct from acetylene has an aromatic character and hence is highly stabilized with respect to the C2H4NO2+ adduct from ethylene. Both cycloadducts tend to isomerize into O-nitroso derivatives, that is, nitrosated ketene and nitrosated acetaldehyde, which represent the thermodynamically most stable products from the addition of NO2+ to acetylene and ethylene, respectively. As prototypal examples of the reactivity of free nitronium ions with most simple pi systems, the reactions investigated are useful starting points to model the mechanism of aromatic nitration.
Ewing's sarcoma is a primitive highly malignant tumor of bone and soft tissues usually metastasizing to bone, bone marrow, and lung. Growth factor receptors and their ligands may be involved in its growth and dissemination. We analyzed the expression of c-kit and its ligand stem cell factor (SCF) in a panel of six Ewing's sarcoma cell lines. All cell lines exhibited substantial levels of surface c-kit expression, and five of six displayed transmembrane SCF on the cell surface. Expression of c-kit was down-modulated in all lines by exposure to exogenous SCF. The SCF treatment was able to confer to cells a growth advantage in vitro, due both to an increase in cell proliferation and to a reduction in the apoptotic rate. When used in the lower compartment of a migration chamber, SCF acted as a strong chemoattractant for Ewing's sarcoma cells. The pretreatment of cells with SCF reduced their chemotactic response to SCF. In athymic nude mice, Ewing's sarcoma cells injected intravenously metastasized to the lung and to a variety of extrapulmonary sites, including bone and bone marrow. Metastatic sites resembled those observed in Ewing's sarcoma patients and corresponded to SCF-rich microenvironments. The in vitro pretreatment of cells with SCF strongly reduced the metastatic ability of Ewing's sarcoma cells, both to the lung and to extrapulmonary sites. This could be dependent on the down-modulation of c-kit expression observed in SCF-pretreated cells, leading to a reduced sensitivity to the chemotactic and proliferative actions of SCF. Our results indicate that the response to SCF mediated by c-kit may be involved in growth, migration, and metastatic ability of Ewing's sarcoma cells.
Mycorrhizal ascomycetous fungi are obligate ectosymbionts that colonize the roots of gymnosperms and angiosperms. In this paper we describe a straightforward approach in which a combination of morphological and molecular methods was used to survey the presence of potentially endo- and epiphytic bacteria associated with the ascomycetous ectomycorrhizal fungus Tuber borchii Vittad. Universal eubacterial primers specific for the 5' and 3' ends of the 16S rRNA gene (16S rDNA) were used for PCR amplification, direct sequencing, and phylogenetic analyses. The 16S rDNA was amplified directly from four pure cultures of T. borchii Vittad. mycelium. A nearly full-length sequence of the gene coding for the prokaryotic small-subunit rRNA was obtained from each T. borchii mycelium studied. The 16S rDNA sequences were almost identical (98 to 99% similarity), and phylogenetic analysis placed them in a single unique rRNA branch belonging to the Cytophaga-Flexibacter-Bacteroides (CFB) phylogroup which had not been described previously. In situ detection of the CFB bacterium in the hyphal tissue of the fungus T. borchii was carried out by using 16S rRNA-targeted oligonucleotide probes for the eubacterial domain and the Cytophaga-Flexibacter phylum, as well as a probe specifically designed for the detection of this mycelium-associated bacterium. Fluorescent in situ hybridization showed that all three of the probes used bound to the mycelium tissue. This study provides the first direct visual evidence of a not-yet-cultured CFB bacterium associated with a mycorrhizal fungus of the genus Tuber.
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Why organize a training course destined for health care professionals which is specifically devoted to cultural mediation in the sphere of health care? There are several reasons justifying such an initiative, mainly relating to the social and cultural mutations pertaining to the present world situation. In fact, two major phenomena may be said to directly influence the health care scene in the current context of generalized migration: the internationalization of diseases on the one hand and on the other hand, the cultural plurality to be found to an increasing degree in society in general. While the responses to the first scenario fall within the limits of standard medical practice, those which are necessitated by the second situation demand a widening of expertise. By reason of the relationship they establish with migrants, it is mandatory that carers should modify their own personal attitudes as well as their professional framework. In the face of the requirements imposed by cross-culture, it is imperative to move in the direction of co-discipline.
BACKGROUND: Hepatitis C virus (HCV) infection has been associated with mixed cryoglobulinaemia. AIM: To investigate the efficacy of anti-viral therapy on the eradication of HCV and its clinical manifestations in patients with HCV-associated symptomatic mixed cryoglobulinaemia. PATIENTS AND METHODS: 18 out of 32 patients with symptomatic mixed cryoglobulinaemia (MC group) received a 12-month course of interferon (3 MU three times a week, subcutaneously). Nonresponders or relapsers to this therapy were treated with interferon plus ribavirin (1200 mg/day, orally) for 12-months. 226 patients with HCV infection and without cryoglobulins were studied in comparison (Hepatitis C group). Serial quantification of serum HCV-RNA and cryoglobulins were performed. RESULTS: In the MC group, 10 out of 18 patients (55%) receiving interferon showed an end of treatment response, but at the end of follow-up, only five (28%) patients had a sustained response. In the hepatitis C group, 91 patients (47%) showed an end of treatment response but only 42 (20%) a sustained response. In the MC group alanine transaminase, cryocrit and rheumatoid factor decreased significantly in responders, with an improvement or disappearance of the MC-associated clinical manifestations. Alanine transaminase, cryocrit and rheumatoid factor increased in the relapsers and the clinical manifestations reappeared. Nonresponders and relapsers to interferon in the MC group were retreated with interferon plus ribavirin. Five out of eight nonresponders showed a end of treatment response but it was sustained in three of them. In the relapsers, treatment with combined therapy achieved a sustained response in four out of the five patients (80%). CONCLUSIONS: Interferon as monotherapy or combined with ribavirin is a safe and effective treatment in patients with HCV-associated MC. The presence of cryoglobulins does not affect the response to anti-viral treatment in patients with HCV infection. The eradication of HCV is associated with an improvement or disappearance of MC-associated clinical manifestations.
Nitric oxide, prostacyclin, and glucagon have been implicated in promoting the hyperdynamic circulatory state of portal hypertension. Recent evidence also indicates that increased tumor necrosis factor-alpha (TNF-alpha) production is involved in the pathogenesis of this hemodynamic abnormality. This study was aimed at investigating in rats with portal vein stenosis (PVS) the effects on splanchnic hemodynamics of blocking circulating TNF-alpha and the factors mediating the vascular action of this cytokine in this setting. Anti-TNF-alpha polyclonal antibodies or placebo was injected into rats (n = 96) before and 4 days after PVS (short-term inhibition) and at 24 h and 4, 7, 10 days after PVS (long-term inhibition). Short-term TNF-alpha inhibition reduced portal venous inflow and cardiac index and increased splanchnic and systemic resistance. Portal pressure was unchanged, but portal-systemic shunting was decreased. After long-term TNF-alpha inhibition, portal venous inflow and portal pressure were unchanged, but arterial pressure and systemic resistance rose significantly. Anti-TNF-alpha PVS rats exhibited lower increments of systemic resistance after Nomega-nitro-L-arginine methyl ester and indomethacin administration and lower serum levels of TNF-alpha, nitrates-nitrites, and 6-keto-PGF1alpha, both over the short and the long term. Serum glucagon levels rose after long-term inhibition. In conclusion, the specific role played by TNF-alpha in the development of the hyperdynamic state of portal hypertension appears to be mainly mediated through an increased release of nitric oxide and prostacyclin. Maintenance of the splanchnic hyperemia after long-term TNF-alpha inhibition could be due to a compensatory release of glucagon.
Human rhabdomyosarcoma cells produce autocrine and paracrine growth factors that can sustain their growth and malignancy. Here we report constitutive production of stem cell factor (SCF) by 5 of 5 human rhabdomyosarcoma cell lines both of alveolar and embryonal histotype. SCF production, ranging from 30 to 162 pg/ml, was independent from the degree of myogenic differentiation and was not modulated by exogenous addition of retinoic acid (RA) or tumor necrosis factor-alpha (TNF-alpha). Four of 5 rhabdomyosarcoma cell lines expressed the mRNA for SCF receptor c-kit, while the 5th cell line became weakly positive for c-kit mRNA only after stimulation with retinoic acid. On the cell surface, c-kit protein was detectable at very low levels in only 1 of 5 rhabdomyosarcoma cell lines and was not up-regulated by RA or TNF-alpha. Addition of anti-c-kit and anti-SCF blocking antibodies, or of exogenous SCF did not alter the in vitro growth ability of rhabdomyosarcoma cells. In conclusion, our data show that rhabdomyosarcoma cells produce consistent amounts of SCF but did not demonstrate autocrine growth modulation. SCF secretion may thus have a paracrine, rather than an autocrine activity in this tumor.