Hospital-based prevalence and sensitivity of high-risk human papillomavirus in Thai urban population

Background: To study the prevalence of high-risk human papillomavirus (HPV) types 16, 18, 31 and 33 in healthy Thai women using polymerase chain reaction (PCR) technique. Material and method: Two hundred and sixty three healthy urban women in Pathumthani, Thailand were recruited. Cervical cancer screening was performed and residual specimen from Pap smears was subjected to PCR to identify the presence of HPV types 16, 18, 31 and 33. Individuals’ demographic, health-specific and sexual behavior data were also collected. Results: Colposcopic biopsy revealed cases with high-grade squamous intraepithelial lesions (HSIL) and low-grade squamous intraepithelial lesions (LSIL). HPV 16 and 18 positive results were associated with abnormal Pap smears. Genotyping gave a 6.1%, 11.8%, 12.1%, and 14.1%, prevalence for HPV types 16, 18, 31 and 33, while 25% were infected with multiple HPV types. Discussion: High-risk HPV screening, used with abnormal pathology of HSIL gives 100% sensitivity and negative predictive value. Data from patient showed not significant correlation with neither different religion level of education, marital status, age of first sexual experience nor the number of sexual partners. Thus high-risk HPV screening is a recommended procedure with excellent sensitivity for detecting HSIL.     

Arabidopsis PCH2 Mediates Meiotic Chromosome Remodeling and Maturation of Crossovers

Meiotic chromosomes are organized into linear looped chromatin arrays by a protein axis localized along the loop-bases. Programmed remodelling of the axis occurs during prophase I of meiosis. Structured illumination microscopy (SIM) has revealed dynamic changes in the chromosome axis in Arabidopsis thaliana and Brassica oleracea. We show that the axis associated protein ASY1 is depleted during zygotene concomitant with synaptonemal complex (SC) formation. Study of an Atpch2 mutant demonstrates this requires the conserved AAA+ ATPase, PCH2, which localizes to the sites of axis remodelling. Loss of PCH2 leads to a failure to deplete ASY1 from the axes and compromizes SC polymerisation. Immunolocalization of recombination proteins in Atpch2 indicates that recombination initiation and CO designation during early prophase I occur normally. Evidence suggests that CO interference is initially functional in the mutant but there is a defect in CO maturation following designation. This leads to a reduction in COs and a failure to form COs between some homologous chromosome pairs leading to univalent chromosomes at metaphase I. Genetic analysis reveals that CO distribution is also affected in some chromosome regions. Together these data indicate that the axis remodelling defect in Atpch2 disrupts normal patterned formation of COs.