Experimental autoallergic sialadenitis in the LEW rat. I. Parameters of disease induction

Experimental autoallergic sialadenitis (EAS) is an autoimmune mononuclear cell infiltration of the submandibular salivary gland that results in tissue destruction and glandular dysfunction. A previous report has described an animal model of induced EAS in LEW rats following sensitization with allogeneic WF submandibular gland (SMG). The present study extends this observation to an EAS disease model induced following sensitization of LEW rats with syngeneic LEW SMG. Furthermore, we describe the characterization of the mononuclear cells in the glandular infiltrates, evaluate the production of autoantibodies, and establish the parameters important for reproducible induction of EAS. Our results demonstrate that EAS can be induced in a completely syngeneic system and the histopathology of disease induction in the syngeneic and allogeneic model systems is similar. Helper/inducer (CD4+) and suppressor/cytotoxic (CD8+) T-cell subsets are the dominant cell types in the salivary mononuclear cell infiltrate. An anti-duct autoantibody was found in the serum of virtually all LEW rats with EAS. Although closely associated with disease development, the presence of this antibody was not a prerequisite for development of histopathologic disease. Induction of disease in both the syngeneic and allogeneic models of EAS is dependent upon administration of Bordetella pertussis at the time of sensitization. Finally, the histopathology of the cellular infiltrates in both the allogeneic and syngeneic models of EAS resemble those observed in the salivary tissues of Sj?gren's patients. While there are several differences between EAS in the LEW rat and the full expression of Sj?gren's syndrome, EAS may serve as a model to study the salivary gland component of this complex human disease.     

Absence of RT6+ T cells in diabetes-prone biobreeding/Worcester rats is due to genetic and cell developmental defects

Diabetes-prone BB/Wor (DP) rats lack the RT6+ peripheral T cell subset whereas diabetes-resistant BB/Wor rats have normal numbers of RT6+ T cells. Lymphocyte transfusion experiments and in vivo depletion studies have demonstrated that RT6+ T cells have an important regulatory role in the pathogenesis of insulin-dependent diabetes mellitus in BB/Wor rats. In the present study, the results of genetic complementation studies indicate that the DP rat contains an intact RT6 gene, but fails to express the RT6.1 alloantigen in the functional absence of an accessory factor (provided by RT6+ cells). At the cellular level, irradiation chimeras demonstrate that the absence of RT6+ T cells in DP rats is due to an intrinsic defect that results in abnormal development and/or differentiation of prothymocytes into RT6+ T cells. The inability of DP prothymocytes to generate RT6+ T cells is not due to serum autoantibodies, lack of accessory cells, or to the presence of inhibitory cells. Inasmuch as DP bone marrow can transfer the susceptibility for diabetes to irradiated recipients, our present results suggest that an important predisposing factor for insulin-dependent diabetes mellitus in DP rats is the inability of DP prothymocytes to generate RT6+ T cells.     

Human Papillomavirus Infection: Knowledge, Attitudes, and Behaviors among Lesbian, Gay Men, and Bisexual in Italy

Background

This cross-sectional study assess knowledge, attitudes, and behavior towards the human papillomavirus (HPV) and the vaccination among a random sample of 1000 lesbian, gay men, and bisexual women and men.

Methods

A face-to-face interview sought information about: socio-demographic characteristics, knowledge about HPV infection, perception of risk towards HPV infection and/or cervical, anal, and oropharyngeal cancers, perception of the benefits of a vaccination to prevent cervical, anal, and oropharyngeal cancers, sexual behaviors, health-promoting behaviors, and willingness to receive the HPV vaccine.

Results

Only 60.6% had heard about the HPV infection and this knowledge was significantly higher in female, in those being a member of a homosexual association, in those having had the first sexual experience at a younger age, in those having received information about the HPV infection from physicians, and in those having no need of information about HPV infection. A higher perceived risk of contracting HPV infection has been observed in those younger, lesbian and gay men, who have heard of HPV infection and knew the risk factors and its related diseases, who have received information about HPV infection from physicians, and who need information about HPV infection. Only 1.7% have undergone HPV immunization and 73.3% professed intent to obtain it in the future. The significant predictors of the willingness to receive this vaccine were belief that the vaccination is useful, perception to be at higher risk of contracting HPV infection, and perception to be at higher risk of developing cervical, anal, and oropharyngeal cancers.

Conclusions

Information and interventions are strongly needed in order to overcome the lack of knowledge about HPV infection and its vaccination. Inclusion of boys in the national vaccination program and initiate a catch-up program for men who have sex with men up to 26 years may reduce their burden of HPV-related disease.     

Anisotropic constitutive equations and experimental tensile behavior of brain tissue

The present study deals with the experimental analysis and mechanical modeling of tensile behavior of brain soft tissue. A transversely isotropic hyperelastic model recently proposed by Meaney (2003) is adopted and mathematically studied under uniaxial loading conditions. Material parameter estimates are obtained through tensile tests on porcine brain materials accounting for regional and directional differences. Attention is focused on the short-term response. An extrapolation of tensile test data to the compression range is performed theoretically, to study the effect of the heterogeneity in the tensile/compressive response on the material parameters. Experimental and numerical results highlight the sensitivity of the adopted model to the test direction.     

Reproductive Performance,Udder Health,and Antibiotic Resistance in Mastitis Bacteria isolated from Norwegian Red cows in Conventional and Organic Farming

Background  

The objectives of this study were to investigate whether there were differences between Norwegian Red cows in conventional and organic farming with respect to reproductive performance, udder health, and antibiotic resistance in udder pathogens.