No abstract

Ionophore topology has a profound effect on the behavior of ion-selective electrodes. This is demonstrated with a new class of ionophores that incorporates aminochromenone moieties linked through urea spacers to different scaffolds that preorganize the ionophore binding cleft into tripodal topologies. Tris(2-aminoethylamine) and cis-1,3,5-tris(aminomethyl)cyclohexane were employed as the scaffolds. The two differ in their rigidity and in the size of ionophore cavity that they create. The electrodes based on the ionophore that incorporates the tris(2-aminoethylamine) scaffold show anti-Hofmeister behavior with an improved selectivity for sulfate. In contrast, the ionophore with the cis-1,3,5-tris(aminomethyl)cyclohexane scaffold exhibits a more Hofmeister-like response.

Objective: To elucidate which anatomical sites need to be sampled to detect human papillomavirus (HPV) infection in the lower male genital tract. Method: In an HPV survey of Mexican soldiers (median age 24 years; range 16-50 years), a cell sample from 2 cm deep into the distal urethra (group 1; n = 168 men), or 0.5 cm deep into the meatus urethralis (group 2; n = 414 men) was collected, along with a sample from the external genitalia. The different samples were tested for 27 HPV types using a polymerase chain reaction based strip assay. Results: HPV DNA was detected more frequently in external genitalia samples (46.4%) than in the urethra (20.8%) or meatus samples (12.1%). Lack of samples from the urethra or meatus would have led to 5.1% and 1.5% false HPV negative results, respectively. The most frequently detected high risk HPV types (HPV 59, 52, 51, and 16) were similar in different sites, whereas low risk types were found rarely in urethra samples.Conclusions: The addition of cell samples from the meatus to those from external genitalia contributed negligibly to the evaluation of the prevalence of HPV in men. HPV detection was slightly improved by the addition of urethra samples, but the gain may not justify the discomfort of the procedure in large epidemiological studies.T he prevalence of human papillomavirus (HPV) in the genital tract of men tends to be similar to that in women (that is, between 3% and 40%, depending upon the population and age group considered). [1][2][3][4][5][6][7][8] It is unclear, however, which genital sites need to be sampled to detect HPV in men. Exfoliated cells were collected from the meatus urethralis and from the distal urethra in certain studies, 7 but urethral sampling is painful and can potentially decrease participation, especially in follow up studies.We therefore compared the relative contribution of cell samples from the external genitalia and the distal urethra or meatus urethralis to the evaluation of HPV prevalence. METHODSThe present report deals with the first 820 men recruited between February 2001 and October 2002 in a larger study on HPV prevalence in 1612 Mexican soldiers. An age stratified random sample was drawn from a list of soldiers who were attending a 1 year minimum period of service in central Mexico. Overall, 7.5% of the men contacted refused to participate in the study and 1.4% could not attend because of concurrent illnesses. All study participants were fully informed of study aims and procedures and signed an informed consent form. The study was cleared by the ethics committee of the National Institute of Public Health of Mexico, and the International Agency for Research on Cancer.Participants were instructed not to wash their genitalia 12 hours before the urological examination. Samples were collected using a cytobrush (Cytobrush Plus Sterile, Medscand Medical Inc, Hollywood, FL, USA), moistened in phosphate buffered saline (PBS), to brush the penis in a continuously rotational movement, from bottom to top, starting at the middle third of the scrot...

BackgroundAlthough human papillomavirus (HPV) infection in heterosexual couples has been sparsely studied, it is relevant to understand disease burden and transmission mechanisms. The present study determined the prevalence and concordance of type-specific HPV infection as well as the determinants of infection in heterosexual couples in a rural area of Mexico.MethodsA cross-sectional study was conducted in 504 clinically healthy heterosexual couples from four municipalities in the State of Mexico, Mexico. HPV testing was performed using biotinylated L1 consensus primers and reverse line blot in cervical samples from women and in genital samples from men. Thirty-seven HPV types were detected, including high-risk oncogenic types and low-risk types. Multivariate logistic regression models were utilized to evaluate factors associated with HPV.ResultsThe prevalence of HPV infection was 20.5% in external male genitals and 13.7% in cervical samples. In 504 sexual couples participating in the study, concordance of HPV status was 79%; 34 partners (6.7%) were concurrently infected, and 21 out of 34 partners where both were HPV positive (61.8%) showed concordance for one or more HPV types. The principal risk factor associated with HPV DNA detection in men as well as women was the presence of HPV DNA in the respective regular sexual partner (OR = 5.15, 95%CI 3.01-8.82). In men, having a history of 10 or more sexual partners over their lifetime (OR 2.5, 95%CI 1.3 - 4.8) and having had sexual relations with prostitutes (OR 1.7, 95%CI 1.01 - 2.8) increased the likelihood of detecting HPV DNA.ConclusionsIn heterosexual couples in rural regions in Mexico, the prevalence of HPV infection and type-specific concordance is high. High-risk sexual behaviors are strong determinants of HPV infection in men.

Population-based programs using HR-HPV testing can improve cervical cancer prevention and control in Mexican and other populations where cytological screening is inadequate for detecting precursors of cervical cancer.