Inbreeding Affects Female Preference for Symmetry in Computer-Animated Sticklebacks

Fluctuating asymmetries are small random deviations from perfect symmetry in bilateral traits caused by the inability of individuals to cope with stress during development. The degree of asymmetry of secondary sexual characters is supposed to convey information about a male's phenotypic and/or genetic quality, and females are thus expected to use bilateral symmetry as a cue in mate choice. We offered female three-spined sticklebacks (Gasterosteus aculeatus L.) that had been inbred for one generation and outbred control females the choice between computer-animated male models differing exclusively in the symmetry of their pelvic spines. Inbred females exhibited a significantly stronger preference for the symmetric model than outbred females, suggesting that females of relatively poor quality are more prepared to pay the costs of choosiness and obtain higher marginal benefits from their discrimination than females of better quality.     

Anti-MOG autoantibodies in Italian multiple sclerosis patients: specificity, sensitivity and clinical association

There is considerable evidence that multiple sclerosis (MS) is an immune-mediated disease characterized by infiltration of inflammatory cells into the CNS and demyelination. Several myelin proteins may be encephalitogenic, including myelin basic protein, proteolipid protein and myelin oligodendrocyte glycoprotein (MOG), the latter being expressed on the external layer of myelin sheaths and hence accessible to antibody attack. We investigated MOG autoreactivity in serum and cerebrospinal fluid (CSF) by ELISA, employing the recombinant extracellular domain of MOG as antigen. We tested serum samples from 262 MS patients (175 relapsing-remitting, 43 primary progressive and 44 secondary progressive), 131 patients with other neurological diseases (OND) and 307 healthy controls. No patients or controls were receiving immunomodulating treatments. We found anti-MOG antibodies in the serum of 13.7% MS patients, mainly in those with secondary progressive MS (25%), in 13.7% of OND patients and in 6.2% of controls. We found a direct correlation (R(2) = 0.6, P = 0.002) between disease severity and anti-MOG titer only in patients with primary and secondary progressive MS. Anti-MOG antibodies were present in the CSF of 11.4% MS patients and 18.9% OND patients. Intrathecal synthesis of anti-MOG antibodies was demonstrated in four (4.5%) of MS patients and no OND patients. Anti-MOG antibodies are not specific for MS; however, they may characterize a subset of MS patients and this may be revealed by serial assays in relation to changing disease phase.     

Drug resistance mutations and newly recognized treatment-related substitutions in the HIV-1 protease gene: prevalence and associations with drug exposure and real or virtual phenotypic resistance to protease inhibitors in two clinical cohorts of antiretroviral experienced patients

This study aimed at identifying HIV-1 protease amino acid changes associated with protease inhibitor (PI) exposure and susceptibility. New amino acid substitutions were correlated with the number of experienced PIs, reaching statistical significance only for those at positions 3, 44, and 74. The correspondence multivariate model demonstrated that > or =3 experienced PIs and substitutions or mutations at positions 3, 46, 54, 73, 74, and 84 were correlated with PI cross-resistance, including resistance for lopinavir and amprenavir in this cohort of patients who were naive for these drugs.     

Guidelines for the appropriate use of genetic tests in infertile couples

Research on genetic causes of male and female infertility rapidly expanded in the last years, following the development of in vitro fertilising techniques. Genetic tests are now available to explore the cause of the infertility and assess the risk of a given couple to transmit its genetic characteristics. This allows at-risk couples to take an informed decision when electing for a medically assisted reproduction. It also allows the professionals to offer a prenatal diagnosis when appropriate. Thus, the genetic work-up of the infertile couple has become good practice for an appropriate diagnosis, treatment and prognostic assessment. The lack of national or international rules for the genetic approach to the infertile couple, prompted the Italian community of professionals in the field of reproductive medicine to join and set up guidelines for the genetic diagnosis of male and female infertility. The group of clinical and research experts is representative of 12 national scientific societies and was supported by external experts from four international societies. We examine the clinically relevant genetic causes of male and female infertility and suggest the category of patients for which each genetic test is recommended or optional, both for an accurate diagnosis and prior to ART.     

Localization of Hepatocyte Growth Factor and Its Receptor met in Endocrine Cells and Related Tumors of the Gut and Pancreas: An Immunohistochemical Study

Hepatocyte growth factor (HGF), a stimulator of angiogenesis and cell migration, regulates the growth of a wide variety of cells by binding to its high-affinity receptor met and is involved in the growth and aggressiveness of several tumors. In this study we investigated the expression of HGF and met in normal endocrine cells and related neoplasms of the gut and pancreas to verify their possible role in tumor pathogenesis, growth, and aggressiveness. Normal tissues and 60 different endocrine tumors were immunostained using specific antibodies directed against HGF, met, and various hormones. HGF immunoreactivity (IR) was found in antroduodenal G cells, rectal enterochromaffin (EC) cells, and pancreatic A and B cells, whereas met IR was detected in antral EC and G cells, and in pancreatic B cells; 46 of 60 tumors examined were positive for HGF, and they were mainly represented by ECL-, EC-, and L-cell neoplasms. met IR was identified in 50/60 tumors of various phenotypes. HGF and met coexpression was found in 42/60 cases, most of which were represented by EC-cell tumors. HGF/met coexpression was significantly more frequent in ileolonic EC-cell tumors, which in the majority of cases were malignant, than in appendiceal EC-cell tumors, which were all benign. Our results demonstrated, for the first time, that HGF and met are specifically distributed in normal gut and pancreatic endocrine cells and, in addition, suggest that HGF and met may be implicated as autocrine/paracrine factors regulating the growth of gastroenteropancreatic endocrine tumors, mainly of ileocolonic EC-cell carcinoids.     

Bradykinin differentiates human lung fibroblasts to a myofibroblast phenotype via the B2 receptor

BACKGROUND: The identification of factors mediating the transition of lung fibroblasts into myofibroblasts is considered fundamental in the comprehension of abnormal reparative processes. Bradykinin, a mediator known for its proinflammatory action, is able to induce cytokine production and contractility in fibroblast cultures. OBJECTIVES: In this study the ability of bradykinin to drive fibroblast into a myofibroblast phenotype at the cellular and molecular level was evaluated. METHODS: alpha-Smooth muscle actin (alpha-SMA) expression and TGF-beta in bradykinin stimulated fibroblasts were tested by means of flow cytometry, Western blot, and RT-PCR. Cell proliferation and collagen production were evaluated by the colorimetric methylthiazol tetrazolium assay and sirius red assay, respectively. Which bradykinin receptor mediates the expression of alpha-SMA was evaluated using selective B1 and B2 blocking agents. Furthermore, the effect of bradykinin on extracellular signal-regulated kinase 1/2 phosphorylation was explored. RESULTS: Bradykinin caused in lung fibroblasts a significant increase in alpha-SMA at the cellular and molecular level. The B2 receptor was held responsible for this effect because a specific receptor antagonist had entirely blocked this effect. Bradykinin was able to induce fibroblast proliferation and collagen production. Bradykinin significantly activated mitogen-activated protein kinase pathway by phosphorylating extracellular signal-regulated kinase 1/2, whereas PD98059, a specific inhibitor, was able to block myofibroblast induction. Although bradykinin induced an increase of TGF-beta on fibroblasts, the blockage of this cytokine did not alter alpha-SMA expression. CONCLUSION: The data support the hypothesis that bradykinin may be involved in bronchial remodeling and lung fibrosis beyond its well recognized proinflammatory activity, also suggesting a new potential therapeutic strategy to control altered reparatory processes.     

Sodium hypochlorite-, chlorine dioxide- and peracetic acid-induced genotoxicity detected by the Comet assay and Saccharomyces cerevisiae D7 tests

Mutagenicity of drinking water is due not only to industrial,agricultural and urban pollution but also to chlorine disinfectionby-products. Furthermore, residual disinfection is used to providea partial safeguard against low level contamination and bacterialre-growth within the distribution system. The aims of this studywere to further evaluate the genotoxic potential of the worldwide used disinfectants sodium hypochlorite and chlorine dioxidein human leukocytes by the Comet assay and in Saccharomycescerevisiae strain D7 (mitotic gene conversion, point mutationand mitochondrial DNA mutability, with and without endogenousmetabolic activation) and to compare their effects with thoseof peracetic acid, proposed as an alternative disinfectant.All three disinfectants are weakly genotoxic in human leukocytes(lowest effective dose 0.2 p.p.m. for chlorine dioxide, 0.5p.p.m. for sodium hypochlorite and peracetic acid). The resultsin S.cerevisiae show a genotoxic response on the end-pointsconsidered with an effect only at doses higher (5- to 10-fold)than the concentration normally used for water disinfection;sodium hypochlorite and peracetic acid are able to induce genotoxiceffects without endogenous metabolic activation (in stationaryphase cells) whereas chlorine dioxide is effective in growingcells. The Comet assay was more sensitive than the yeast tests,with effective doses in the range normally used for water disinfectionprocesses. The biological effectiveness of the three disinfectantson S.cerevisiae proved to be strictly dependent on cell-specificphysiological/biochemical conditions. All the compounds appearto act on the DNA and peracetic acid shows effectiveness similarto sodium hypochlorite and chlorine dioxide. ¹Author to whom correspondence should be addressed. Tel: +39 0521 905608; Fax: +39 0521 905604; Email: mutgen{at}unipr.it Received on September 22, 2003; revised and accepted on November 27, 2003     

Saccharomyces cerevisiae as an eukaryotic cell model to assess cytotoxicity and genotoxicity of three anticancer anthraquinones

The toxicity of most drugs is associated with their enzymatic conversion to toxic metabolites. Bioactivation reactions occur in a range of cellular organs and organelles, including mitochondria. We have investigated different effects (i.e. growth inhibition, mortality and genotoxicity) of doxorubicin, epirubicin and mitoxantrone on the D7 strain of Saccharomyces cerevisiae and on its petite (rho degrees ) respiratory-deficient mutant at various cellular concentrations of cytochrome P450 and glutathione (GSH). The data confirmed the importance of oxygen production for doxorubicin toxicity. The complete absence, or a very low level, of cytochrome oxidase subunit IV conferred some resistance to doxorubicin. Low GSH levels decreased resistance to doxorubicin in both strains, suggesting that thiol depletion could potentiate membrane lipid peroxidation. Doxorubicin induction of petite colonies suggests that the drug is able to select rather than induce respiratory-deficient mutants. Epirubicin induced levels of cytotoxicity similar to those of doxorubicin. The effects did not appear to be significantly dependent on mitochondrial function or GSH levels, whereas cells were strongly protected by cytochrome P450. GSH did not induce an evident alteration. Neither were genotoxic effects induced. Mitoxantrone had reduced levels of both growth inhibition and cytotoxicity in comparison to anthracyclines and induced convertants, revertants and aberrants. All the effects considered were amplified at high cytochrome P450 cellular concentrations, although the drug was also shown to act without previous metabolism via cytochrome P450. Anthracenedione effectiveness was increased by metabolism via cytochrome P450 and partially reduced by GSH. However, further mechanisms were suggested, which might implicate mitochondrial function and/or production of electrophilic cytotoxic and/or genotoxic intermediates by means of GSH conjugation. The biological effectiveness of doxorubicin, epirubicin and mitoxantrone on S.cerevisiae was shown to be strictly dependent on cell-specific physiological/biochemical conditions, such as a functional respiratory chain and levels of cytochrome P450 and GSH.