Modulation of pro- and anti-apoptotic genes in lymphocytes exposed to bone cements

The ability of bone cements to modify the apoptotic program in activated immune cells and the mechanisms by which they act were evaluated. Mononuclear cells were collected from healthy individuals, cultured for 4 and 24 h with phytohemoagglutinina-P and cement extracts and then tested to assess: (a) cell viability; (b) early apoptotic events, by Annexin V/propidium iodide staining; and (c) the expression of pro- (p53, c-myc, ICE) and anti-apoptotic (bcl-2) genes. After 4 h three cements were able to increase significantly the percentage of apoptotic cells, while after 24 h no differences were found. The proportion of dead cells was not significantly changed at either culture time. The simultaneous expression of both pro-apoptotic (ICE, c-myc, p53) and antiapoptotic genes (bcl-2) was investigated only with regard to the materials which induced significant changes in apoptosis: two cements induced the p53 expression, while the third down-regulated bcl-2. As apoptosis regulates the balance of immune response, the authors recommend that the interaction between materials and immune cells should be assessed, so that the use of pro-apoptotic materials may be avoided in patients with immune defects.     

Inferring the potential success of pneumococcal vaccination in Italy: serotypes and antibiotic resistance of Streptococcus pneumoniae isolates from invasive diseases

To evaluate the potential impact of antipneumococcal vaccination in Italy, Streptococcus pneumoniae isolates from invasive disease were collected from 65 laboratories in the years 1997-2000. Of the 503 isolates examined, 15% were from children <5 years and 34% from adults > or = 65 years. The most frequent serogroups were, in ranking order, 14, 19, 6, and 23. Overall, 93.8% of the isolates belonged to serogroups enclosed in the 23-valent polysaccharide vaccine. Among children isolates, serotypes 14, 6B, and 23F comprised 60% of the isolates; overall, 72% of the isolates belonged to serotypes included in the heptavalent conjugate vaccine. Penicillin nonsusceptible isolates (10%) belonged to a limited number of serogroups, being more common in serogroups 19 and 9 and in the nonvaccine serogroups 24 and 35. Erythromycin-resistant isolates (29%) belonged to several serogroups, more frequently to serogroups 14, 6, and 19. Both vaccines are potentially able to prevent the majority of resistant infections in the respective age groups in Italy.     

Virological and clinical aspects of multiple hepatitis virus infections: preliminary data of an italian multicentre study

To evaluate the interference between HBV, HCV and HDV and the clinical impact of coinfection as compared with single HBV or HCV infection, we unrolled 618 HBsAg and/or anti-HCV positive subjects (337 with liver biopsy and 281 without liver biopsy) at their first observation at one of the seven Italian Liver Units from 1993 to 1997 (Padova, Rome, Sassari, Naples, Bari, Messina, Palermo). Serum HBV-DNA by dot-blot was found more frequently in patients with HBV infection alone (52% of 133 cases) than in those with HBV-HCV coinfection (28% of 64 cases, p<0.005) or in those with HBV-HDV-HCV coinfection (12% of 25 cases, p<0.0005) or with HBV-HDV coinfection (13% of 8 cases, p<0.05). We observed a higher prevalence of HCV-RNA positive cases in the patients with HCV infection alone (91.2% of 114 cases) than in those with HBV-HCV coinfection (64.5% of 62 cases, p<0.0001) or with HBV-HDV-HCV infection (19% of 21 cases, p<0.0001). These observations suggest a reciprocal inhibition of HBV and HCV genome in multiple hepatitis viral infection. A severe liver disease was more frequently observed in patients with HBV-HCV coinfection (66%) than in those with a single HBV infection (43%, p<0.05) or HCV infection (46%, p<0.05). Anti-HCV positive/anti-HBc positive patients, lacking both HBsAg and anti-HBs, compared with the anti-HCV positive/anti HBc negative ones, more frequently showed severe clinical presentation and less frequently had a sustained response to a-IFN treatment.     

Mycobacterium tuberculosis subverts the differentiation of human monocytes into dendritic cells

Intracellular pathogens have developed strategies for evading elimination by the defenses of the host immune system. Here we describe an escape mechanism utilized by Mycobacterium tuberculosis that involves the interference with the generation of fully competent DC from monocytes. We show that monocytes infected with live M. tuberculosis differentiated into mature, CD83+ and CCR7+ DC (Mt-MoDC), but were characterized by a selective failure in the expression of the family of CD1 molecules. These cells also showed levels of MHC class II and CD80 (B7.1) that were reduced in comparison with LPS-matured DC. In addition, Mt-MoDC produced TNF-alpha and IL-10, but were unable to secrete IL-12. The generation of Mt-MoDC required the infection of monocytes with live M. tuberculosis, since infection with heat-killed bacteria partially abrogated the effects on monocyte differentiation. Interestingly, Mt-MoDC revealed an impaired antigen-presentation function as assessed by the reduced capability to induce proliferation of cord blood T lymphocytes. Further, naive T lymphocytes expanded by Mt-MoDC were unable to secrete cytokines, in particular IL-4 and IFN-gamma, suggesting that they could be ineffective in helping the macrophage-mediated killing of intracellular mycobacteria. Our results suggest that the interference with monocyte differentiation into fully competent DC is an evasion mechanism of M. tuberculosis that could contribute to its intracellular persistence by avoiding immune recognition.     

The beneficial effects of fractional CO2 laser treatment on perineal changes during puerperium and breastfeeding period: a multicentric study

Lasers in Medical Science - Childbirth is a great change in woman life because of hormonal, physical and psychological alterations that are associated with this process. Dyspareunia and perineal...     

Parental occupation, occupational exposure to solvents and polycyclic aromatic hydrocarbons and risk of childhood brain tumors (Italy, France, Spain)

The role of parental occupational exposure in childhood brain tumorswas investigated in a population-based case-control study grouping 251 casesand 601 controls from three European centers: Milan (Italy), Paris (France),and Valencia (Spain). Parental occupational exposure to solvents andpolycyclic aromatic hydrocarbons (PAH) during the five-year period beforebirth was estimated using a job-exposure matrix developed earlier in the samecountries. Odds ratios (OR) of brain tumors for each occupation andoccupational exposure were estimated by logistic regression, adjusting forchilds age, gender, exposure to tobacco smoke and ionizing radiation,mothers age and years of schooling, and center. The risk of childhood braintumors rose when fathers worked in agriculture (OR = 2.2, 95 percentconfidence interval [CI] = 1.0-4.7) and motor-vehicle-related occupations. Inthe latter group, the risk increased for primitive neuroectodermal tumors inparticular (OR = 2.7, CI = 1.1-6. 6). Astroglial tumors were more frequentamong children of mothers in health services (OR = 2.2, CI = 1.0-4.9).Paternal exposure to PAHs was associated with an increased, but notdose-related, risk of primitive neuroectodermal tumors (OR = 2.0, CI =1.0-4.0), and maternal exposure to solvents at a high level was associatedwith an increased risk of both astroglial (OR = 2.3, CI = 0.9-5.8) andprimitive neuroectodermal tumors (OR = 3.2, CI = 1.0-10.3).     

Early-onset encephalomyopathy associated with tissue-specific mitochondrial DNA depletion: A morphological,biochemical and molecular-genetic study

A male infant, born from consanguineous parents, suffered from birth with a progressive neuromuscular disorder characterized by psychomotor delay, hypotonia, muscle weakness and wasting, deep-tendon areflexia and spastic posture. High levels of lactic acid in blood and cerebrospinal fluid suggested a mitochondrial respiratory chain defect. Muscle biopsy revealed raggedred and cytochromec oxidase-negative fibres, lipid accumulation and dystrophic changes. Multiple defects of respiratory complexes were detected in muscle homogenate, but cultured fibroblasts, myoblasts and myotubes were normal. Southern blot analysis showed markedly reduced levels of mitochondrial DNA (mtDNA) in muscle, while lymphocytes, fibroblasts and muscle precursor cells were normal. Neither depletion of mtDNA nor abnormalities of the respiratory complexes were observed in innervated muscle fibres cultured for as long as 4 months. No mutations were observed in two candidate nuclear genes,mtTFA andmtSSB, retro-transcribed, amplified and sequenced from the proband's mRNA. Sequence analysis of the mtDNA D-loop and of the origin of replication of the mtDNA light strand failed to identify potentially pathogenic mutations of these replicative elements in the proband's muscle mtDNA. Our findings indicate that mtDNA depletion is due to a nuclear encoded gene and suggest that the abnormality underlying defective mtDNA propagation must occur after muscle differentiation in vivo.     

Effects of superoxide dismutase mimetics on the activity of nitric oxide in rat aorta.

A number of structurally distinct superoxide dismutase (SOD) mimetics were examined to determine if they shared the ability of authentic Cu/Zn SOD to produce endothelium-dependent relaxation of rings of rat aorta by protecting basal nitric oxide from destruction by endogenously produced superoxide anion. MnCl2 (10 nM-100 microM), CuSO4 (100 nM-1 mM) and CuDIPS (Cu [II]-[diisopropylsalicylate]2; 100 nM-30 microM) each mimicked the ability of Cu/Zn SOD (0.1-300 u ml(-1)) to produce relaxation of phenylephrine-precontracted aortic rings in a manner inhibited by endothelial removal or treatment with N(G)-nitro-L-arginine methyl ester (L-NAME, 100 microM). In contrast, MnTMPyP (Mn [III] tetrakis [1-methyl-4-pyridyl] porphyrin; 10 nM-30 microM) augmented phenylephrine-induced contraction and this was blocked by endothelial removal or treatment with L-NAME (100 microM), consistent with destruction rather than protection of basal nitric oxide activity. Pretreatment with Cu/Zn SOD (250 u ml(-1)) blocked this augmentation suggesting that it arose paradoxically through destruction of nitric oxide by superoxide anion. The spin trap agents tiron (100 nM-1 mM), tempol (100 nM-1 mM) and PTIYO (4-phenyl-2,2,5,5-tetramethyl imidazolin-1-yloxy-5-oxide; 100 nM-300 microM) all failed to promote endothelium-dependent relaxation. In fact, the last two augmented phenylephrine-induced tone and this was blocked by endothelial removal or treatment with L-NAME (100 microM), consistent with destruction of basal nitric oxide activity. This destruction was unaffected by pretreatment with Cu/Zn SOD (250 u ml(-1)) and probably reflected the direct ability of tempol and PTIYO to destroy nitric oxide. Thus, the ideal SOD mimetic for protection of nitric oxide activity in conditions of oxidant stress still awaits development.     

In vitro and in vivo interaction between cisplatin and topotecan in ovarian carcinoma systems

Topotecan, a camptothecin analogue, is a␣specific inhibitor of topoisomerase I approved for use in the treatment of patients with refractory ovarian carcinoma. The drug's mechanism of action suggests a potential efficacy of drug combinations incorporating DNA-damaging agents. In an attempt better to define a␣rational basis for drug combination we examined the effect of topotecan on the cytotoxicity and antitumor activity of cisplatin in an ovarian carcinoma system growing in vitro and in vivo as a tumor xenograft. The in vitro cell system included a cisplatin-sensitive cell line, IGROV-1, and a cisplatin-resistant subline, IGROV-1/Pt0.5, which is characterized by p53 mutation and loss of normal function of the wild-type gene of the parental cell line. This cell system was chosen since the cell sensitivity to DNA-damaging agents appears to be dependent on p53 gene status. Cytotoxicity was assessed by the growth inhibition assay using different schedules: (a) a 1-h period of cisplatin exposure followed by a 24-h topotecan treatment and (b) a 1-h period of simultaneous exposure to cisplatin and topotecan. In the case of the sequential schedule, an additive interaction was observed in IGROV-1 and IGROV-1/Pt0.5 cells. When the simultaneous schedule was used, a synergistic interaction, more evident for the cisplatin-sensitive cells, was found. On the basis of these observations at a cellular level, the effect of concomitant administration of the two drugs (i.e., the most favorable schedule) was studied in the IGROV-1 tumor xenograft, which is moderately responsive to cisplatin and topotecan. Suboptimal doses of each drug (with a low dose of topotecan, 5.1 mg/kg) achieved an antitumor effect comparable with or superior to that of the optimal dose of a single treatment (tumor weight inhibition, 60%), thus indicating a␣pharmacological advantage of the combination over the single treatment. However, an increase in the topotecan dose (7.1 mg/kg) was associated with an evident increase in the toxicity of the combination, thereby suggesting that the drug interaction was not tumor-specific. Although the molecular basis of the drug interaction is not clear, it is likely that inhibition of topoisomerase I affects the ability of cells to repair cisplatin adducts. Such findings may have pharmacological implications since they suggest the potential clinical interest of topoisomerase I inhibitors in combination with cisplatin. Received: 14 June 1997 / Accepted: 18 September 1997