Commensal microbiota influence systemic autoimmune responses

Antinuclear antibodies are a hallmark feature of generalized autoimmune diseases, including systemic lupus erythematosus and systemic sclerosis. However, the processes underlying the loss of tolerance against nuclear self‐constituents remain largely unresolved. Using mice deficient in lymphotoxin and Hox11, we report that approximately 25% of mice lacking secondary lymphoid organs spontaneously develop specific antinuclear antibodies. Interestingly, we find this phenotype is not caused by a defect in central tolerance. Rather, cell‐specific deletion and in vivo lymphotoxin blockade link these systemic autoimmune responses to the formation of gut‐associated lymphoid tissue in the neonatal period of life. We further demonstrate antinuclear antibody production is influenced by the presence of commensal gut flora, in particular increased colonization with segmented filamentous bacteria, and IL‐17 receptor signaling. Together, these data indicate that neonatal colonization of gut microbiota influences generalized autoimmunity in adult life.     

Prediction of recurrent disease by cytology and HPV testing after treatment of cervical intraepithelial neoplasia

Objective: To assess the role of human papillomavirus (HPV) testing and cytology as predictors of residual/recurrent disease after treatment of high‐grade cervical intraepithelial lesions. Methods: One hundred and thirty‐eight women with cervical intraepithelial neoplasia (CIN) grade 2/3 lesion on biopsy were included in a prospective follow‐up study in Belgium and Nicaragua. All women were treated with loop electrosurgical excision procedure (LEEP) and follow‐up visits took place at 6 weeks, 6 months, 1 year and 2 years. During these visits, a Papanicolaou (Pap) smear test was taken, colposcopy was performed and specimens were collected for HPV testing. Cytology, high‐risk (HR) HPV presence, persistent HR HPV infection and combinations of these tests at different time points during follow‐up were correlated with histologically confirmed residual/recurrent disease. Results: Thirteen patients (9%) developed residual/recurrent disease during follow‐up. Abnormal cytology at 6 weeks after treatment was significantly correlated with residual/recurrent disease. Nine of thirty‐seven patients with abnormal cytology at 6 weeks had recurrent disease versus three of seventy with a normal cytology [odds ratio (OR): 7.2; 95% confidence interval (CI): 1.8–28.5; P = 0.003). Sensitivity of this test was 75.0%, specificity 70.5%. Combining abnormal cytology and the presence of HR HPV within the first 6 months after treatment gave the best correlation with residual/recurrent disease: of the 54 women with abnormal cytology and/or HR HPV presence within the first 6 months, 11 developed residual/recurrent disease (OR 10.2; 95% CI: 2.2–48.3). Sensitivity of this combination was 84.6% and specificity 65.0%. Conclusion: Cytology remains the cornerstone in the early follow‐up after LEEP for CIN lesions of the cervix. HPV testing can add value as it increases the sensitivity of cytology in concomitant testing within the first 6 months.     

Cerebellar neurones: Differentiation and modulation of sensitivity to excitotoxic treatment

The neurite outgrowth and adhesion complex (NOAC), isolated from rabbit sera has been dissociated in its major components by reverse-phase chromatography in HPLC by using a C₁₈ column. SDS-PAGE analisys of the active fractions revealed the presence of three major bands of approximately 100, 70 and 50 kDa. Studies on the biological activity of NOAC were carried out on rat cerebellar granule cells. NOAC-cultured cells exhibit a marked resistance to excitotoxic stimuli carried by glutamate.     

Distribution of the molossinus allele of Sry, the testis-determining gene, in wild mice

When the Y chromosome of the laboratory inbred mouse strain C57BL/6 (B6) is replaced by the Y of certain strains of Mus musculus domesticus, testis determination fails and all XY fetuses develop either as hermaphrodites or XY females (XY sex reversal). This suggests the presence of at least two alleles of Sry, the male-determining gene on the Y:M. m. domesticus and B6. The B6 Y chromosome is derived from the Japanese house mouse, M. m. molossinus and therefore carries a molossinus Sry allele. As a first step to determine how the molossinus Sry allele evolved, its distribution pattern was determined in wild mice. The cumulative data of 96 M. musculus samples obtained from 58 geographical locations in Europe, North Africa, and Asia show the molossinus Sry allele is restricted to Japan and the neighboring Asian mainland and confirm that Japanese M. m. molossinus mice were derived in part from a race of M. m. musculus from Korea or Manchuria. Sry polymorphisms, as illustrated by the molossinus Sry allele, can serve as molecular markers for studies on the evolution of wild M. musculus populations and can help determine the role sex determination plays in speciation.      

Interactions of Photobleaching and Inorganic Nutrients in Determining Bacterial Growth on Colored Dissolved Organic Carbon

Abstract Bacteria are key organisms in the processing of dissolved organic carbon (DOC) in aquatic ecosystems. Their growth depends on both organic substrates and inorganic nutrients. The importance of allochthonous DOC, usually highly colored, as bacterial substrate can be modified by photobleaching. In this study, we examined how colored DOC (CDOC) photobleaching, and phosphorus (P) and nitrogen (N) availability, affect bacterial growth. Five experiments were conducted, manipulating nutrients (P and N) and sunlight exposure. In almost every case, nutrient additions had a significant, positive effect on bacterial abundance, production, and growth efficiency. Sunlight exposure (CDOC photobleaching) had a significant, positive effect on bacterial abundance and growth efficiency. We also found a significant, positive interaction between these two factors. Thus, bacterial use of CDOC was accelerated under sunlight exposure and enhanced P and N concentrations. In addition, the accumulation of cells in sunlight treatments was dependent on nutrient availability. More photobleached substrate was converted into bacterial cells in P- and N-enriched treatments. These results suggest nutrient availability may affect the biologically-mediated fate (new biomass vs respiration) of CDOC.     

Human papillomavirus DNA detection in women with primary abnormal cytology of the cervix: prevalence and distribution of HPV genotypes

OBJECTIVES: In this study, we focus on the prevalence and occurrence of different anogenital human papillomavirus (HPV) genotypes in a first abnormal cervical screening test, and correlate HPV genotyping with the cytological diagnosis on thin-layer liquid-based preparations in routine gynaecological screening. METHODS: Out of 780 abnormal smears, 513 tested positive for HPV. All 25 different HPV types were identified by Line Probe Assay. RESULTS: The prevalence of high-risk HPV types increased from 72% in atypical squamous cell of undetermined significance to 94.5% in high-grade intra-epithelial lesion (HSIL). Co-infection with multiple HPV types was predominantly found in HSIL (35.8%). In the HSIL group the most common HPV types were 16, 52, 51 and 31; type 18 was rarely present. CONCLUSION: The role of types 31, 51 and 52 should be considered in future studies on vaccine development.