Tradeoffs in the sensory brain between diurnal and nocturnal rodents.

INTRODUCTION: Transitions in temporal niche have occurred many times over the course of mammalian evolution. These are associated with changes in sensory stimuli available to animals, particularly with visual cues, because levels of light are so much higher during the day than night. This relationship between temporal niche and available sensory stimuli elicits the expectation that evolutionary transitions between diurnal and nocturnal lifestyles will be accompanied by modifications of sensory systems that optimize the ability of animals to receive, process, and react to important stimuli in the environment. METHODS: This study examines the influence of temporal niche on investment in sensory brain tissue of 13 rodent species (five diurnal; eight nocturnal). Animals were euthanized and the brain immediately frozen on dry ice; olfactory bulbs were subsequently dissected and weighed, and the remaining brain was weighed, sectioned, and stained. Stereo Investigator was used to calculate volumes of four sensory regions that function in processing visual (lateral geniculate nucleus, superior colliculus) and auditory (medial geniculate nucleus, inferior colliculus) information. A phylogenetic framework was used to assess the influence of temporal niche on the relative sizes of these brain structures and of olfactory bulb weights. RESULTS: Compared to nocturnal species, diurnal species had larger visual regions, whereas nocturnal species had larger olfactory bulbs than their diurnal counterparts. Of the two auditory structures examined, one (medial geniculate nucleus) was larger in diurnal species, while the other (inferior colliculus) did not differ significantly with temporal niche. CONCLUSION: Our results indicate a possible indirect association between temporal niche and auditory investment and suggest probable tradeoffs of investment between olfactory and visual areas of the brain, with diurnal species investing more in processing visual information and nocturnal species investing more in processing olfactory information.

1.32 ± 0.11 Ma age for underwater remains constrain antiquity and longevity of the Dominican primate Antillothrix bernensis.

Endemic New World monkeys are an important element of the extinct mammal faunas of the Caribbean's Greater Antilles. Here we report the first geochronometric evidence that the primate Antillothrix bernensis existed in the Dominican Republic during the Pleistocene, based on the uranium-series age of carbonate speleothem that encased a tibia when it was collected in a flooded cave. Three-dimensional geometric morphometrics of laser-scanned living and extinct samples provide evidence to support the hypothesis that this specimen and other Dominican primate tibial remains belong to that same species. U-Th dating of the host cave carbonate returns ages consistently at the 600 ka upper limit of the technique. However, U-Pb, capable of resolving ages of greater antiquity, is more robust in this context, returning a secure age of 1.32 ± 0.11 Ma, which is the oldest chronometric age recorded for a Hispaniolan mammal. While its origins and manner and time of arrival are obscure, the morphometric studies are consistent with phylogenetic analyses that place A. bernensis within the pitheciid clade of the platyrrhines. The species apparently endured for over 1 million years during the climatic perturbations of the Pleistocene, as a frugivorous climbing quadruped, one of two known primate species occupying the hazard prone island of Hispaniola.

Site-specific human papillomavirus infection in adolescent men who have sex with men (HYPER): an observational cohort study.

BACKGROUND: Men who have sex with men (MSM) have an increased risk of anogenital human papilomavirus (HPV) infection, which can lead to HPV-related anogenital lesions such as warts, anal intraepithelial neoplasia, and anal cancer. Some of these HPV types are preventable with vaccines. We aimed to describe the incidence of anal, penile, and oral HPV infection, and to estimate the site-specific transmission probability per partner, for teenage MSM. METHODS: In our observational cohort study, we enrolled teenage MSM (aged 16-20 years) with low sexual exposure and a low prevalence of HPV in Melbourne (VIC, Australia). At baseline, 3, 6, and 12 months, we took a swab from the anal canal, and participants self-collected a swab from the penis and an oral rinse. Our primary outcome was definite and probable incident HPV infection of the anus, penis, or mouth at any time in the 12 months from baseline, assessed through the presence of HPV DNA. We defined definite incident HPV infection as the same HPV type detected more than once from the same site in men who had a negative HPV test at baseline. We defined probable incident HPV infection as only one positive test. We estimated the probability of HPV transmission per partner using HPV prevalence in MSM with a similar age to partners of men in our cohort. This study is registered at the Australian New Zealand Clinical Trials Registry and ClinicalTrials.gov, numbers ACTRN12611000857909 and NCT01422356. FINDINGS: We enrolled 200 MSM aged 16-20 years (median 19 years [IRQ 18-20; range 16-20]) between Sept 20, 2010, and Aug 24, 2012. Over the 12 month follow-up period, we detected 48 definite (107 possible) HPV infections in the anus, ten definite (34 possible) HPV infections on the penis, and no definite (six possible) infections in the mouth. Definite incidence rate per 100 person-years for any anal HPV infection was 57 (95% CI 46-68), and for any anal HPV type in the quadrivalent vaccine was 33 (23-44). Definite incidence rate per 100 person-years for any penile HPV was 12 (6-21) and for any HPV type in the quadrivalent vaccine was 5 (1-12). Estimated probabilities of HPV transmission from the penis to the anus were significantly higher than were those from the anus to the penis (p<0·05 for all HPV types in the quadrivalent vaccine). INTERPRETATION: High incidence rates suggest that the vaccination coverage in MSM will need to be high. The transmission estimates will inform HPV modelling. FUNDING: Merck.

Evaluation of a new method of fossil retrodeformation by algorithmic symmetrization: crania of papionins (Primates, Cercopithecidae) as a test case.

Diagenetic distortion can be a major obstacle to collecting quantitative shape data on paleontological specimens, especially for three-dimensional geometric morphometric analysis. Here we utilize the recently-published algorithmic symmetrization method of fossil reconstruction and compare it to the more traditional reflection & averaging approach. In order to have an objective test of this method, five casts of a female cranium of Papio hamadryas kindae were manually deformed while the plaster hardened. These were subsequently "retrodeformed" using both algorithmic symmetrization and reflection & averaging and then compared to the original, undeformed specimen. We found that in all cases, algorithmic retrodeformation improved the shape of the deformed cranium and in four out of five cases, the algorithmically symmetrized crania were more similar in shape to the original crania than the reflected & averaged reconstructions. In three out of five cases, the difference between the algorithmically symmetrized crania and the original cranium could be contained within the magnitude of variation among individuals in a single subspecies of Papio. Instances of asymmetric distortion, such as breakage on one side, or bending in the axis of symmetry, were well handled, whereas symmetrical distortion remained uncorrected. This technique was further tested on a naturally deformed and fossilized cranium of Paradolichopithecus arvernensis. Results, based on a principal components analysis and Procrustes distances, showed that the algorithmically symmetrized Paradolichopithecus cranium was more similar to other, less-deformed crania from the same species than was the original. These results illustrate the efficacy of this method of retrodeformation by algorithmic symmetrization for the correction of asymmetrical distortion in fossils. Symmetrical distortion remains a problem for all currently developed methods of retrodeformation.

How very young men who have sex with men view vaccination against human papillomavirus.

BACKGROUND: HPV vaccination of men who have sex with men (MSM) prior to the commencement of sexual activity would have the maximum impact on preventing HPV and anal cancer in this population. However, knowledge and attitudes towards HPV vaccination among very young MSM have not been previously studied. METHODS: Two hundred MSM aged 16 to 20 were recruited via community and other sources. Participants were asked about their knowledge and attitudes towards HPV and HPV vaccination. RESULTS: Most (80%, 95% confidence interval (CI) 72.2-87.2%) men were not willing to purchase the vaccine because of its cost (AUD$450). However, if the vaccine was offered to MSM free of charge, 86% (95% CI: 80-90%) reported they would be willing to disclose their sexuality to a health care provider in order to obtain the vaccine. Over half (54%, 95%: 47-61%) of men would only be willing to disclose their sexuality to receive the HPV vaccine after their first experience of anal intercourse. The age at first insertive anal intercourse and the age at first receptive anal intercourse were 0.21 (IQR: -2.5 to 3.2) and 0.17 (IQR: -2.9 to 2.7) years earlier than the age that men would be willing to disclose their sexuality to receive the HPV vaccine, respectively. Willingness to receive the vaccine at a younger age was associated with younger age at first insertive anal intercourse. CONCLUSION: Overall, very young MSM expressed high acceptance of HPV vaccination. Early, opportunistic vaccination of very young MSM may be feasible in settings where very young MSM have not been vaccinated through universal programs targeting school aged males. However, given HPV infections occur early on, the effectiveness of this approach will be less than vaccination targeting school aged boys.

Sexual behaviors and risk for sexually transmitted infections among teenage men who have sex with men.

OBJECTIVES: To report on sexual behaviors and sexually transmitted infections (STIs) among men who have sex with men (MSM) in their teens, when many MSM engage in their first sexual experiences. METHODS: MSM aged 16 to 20 years were recruited via community and other sources. Men completed a questionnaire about their sexual behaviors and were screened for gonorrhea, chlamydia, syphilis, and HIV. RESULTS: Two hundred men were included. The median age was 19 years. The median age at first insertive or receptive anal intercourse was 17 years. Half of men reported sex with mainly older men: these men were more likely to engage in receptive anal intercourse (48% vs. 25%, p < .001) than other men. Most men had engaged in insertive (87%) and receptive (85%) anal intercourse in the prior 12 months with 60% and 53% reporting inconsistent condom use with insertive and receptive anal intercourse partners, respectively. The median number of insertive anal intercourse partners was 3 and 1.5 (p < .001) among men reporting inconsistent and consistent condom use with insertive anal intercourse over the prior 12 months. The median number of receptive anal intercourse partners was 3 and 2 (p = .006) among men reporting inconsistent and consistent condom use with receptive anal intercourse over the prior 12 months. Pharyngeal gonorrhea, rectal gonorrhea, urethral chlamydia, rectal chlamydia, and syphilis were detected in 3.0%, 5.5%, 3.0%, 4%, and 2.0% of men, respectively. All men were HIV negative. CONCLUSION: Many of the teenage MSM in this study were at risk for STI. Preventative messages and STI screening interventions that are age appropriate need to be developed to reduce HIV and STI risk in this under-recognized group.

Early acquisition of anogenital human papillomavirus among teenage men who have sex with men.

BACKGROUND: Anogenital human papillomavirus (HPV) is common among men who have sex with men (MSM) and causes anal cancer. This study examined the determinants of initial anogenital HPV infection among teenage MSM. METHODS: Two hundred MSM aged 16 to 20 years were recruited via community and other sources. Men were tested for HPV DNA from the anus and penis. RESULTS: The proportion of men with anal HPV of any type increased from 10.0% in men reporting no prior receptive anal sex to 47.3% in men reporting ≥ 4 receptive anal sex partners (P < .001).A similar pattern was also seen with HPV type 16 (P = .044). The proportion of men with penile HPV increased from 3.7% in men reporting no prior insertive anal sex to 14.8% in men reporting ≥ 4 insertive anal sex partners (P = .014). Overall, 39.0% (95% confidence interval (CI), 32.2%-46.1%) of men had at least 1 HPV type: 23.0% (95% CI, 17.4%-29.5%) had a vaccine-preventable type (6, 11, 16 or 18). CONCLUSIONS: Early and high per partner transmission of HPV occurred between men soon after their first sexual experiences. HPV vaccination needs to commence early for maximal prevention of HPV among MSM.

Provision of rapid HIV tests within a health service and frequency of HIV testing among men who have sex with men: randomised controlled trial.

OBJECTIVE: To determine if the provision of rapid HIV testing to men who have sex with men attending a health service would increase their frequency of HIV testing over time. DESIGN: Non-blinded randomised controlled trial. SETTING: Public sexual health service in Australia. PARTICIPANTS: Men who reported having a male sexual partner within the previous year and an HIV test within the previous two years. Of 400 men entered, 370 (92.5%) completed the study. INTERVENTIONS: Men attending the service between September 2010 and March 2011 were randomised 1:1 to either ongoing access to rapid HIV testing obtained with finger prick or to conventional HIV serology with venepuncture, over 18 months. MAIN OUTCOME MEASURE: The incidence of all HIV testing after enrolment, including testing outside the study clinic, analysed by intention to treat. RESULTS: Of 200 men randomised to the rapid testing arm, 196 were followed for 288 person years. Of 200 men randomised to the conventional testing arm, 194 were followed for 278 person years. Median time since the last HIV test was six months for both arms. Men in the rapid test arm had 469 tests (mean 1.63 tests a year), and men in the conventional test arm had 396 tests (mean 1.42 tests a year); incidence rate ratio 1.15, 95% confidence interval 0.96 to 1.38; P=0.12. In a post hoc analysis, rates of initial HIV testing during follow-up were 1.32 and 1.01 tests a year, respectively (1.32, 1.05 to 1.65; P=0.02). CONCLUSIONS: Provision of access to rapid HIV testing in a health service did not result in a sustained increase over time in HIV testing by men who have sex with men; however, the rate of initial HIV testing did increase by a third. Further research is required to determine how to achieve sustained increases in the frequency of HIV testing by populations at risk. TRIAL REGISTRATION: ACTR No 12610000430033.

Efficacy of oral metronidazole with vaginal clindamycin or vaginal probiotic for bacterial vaginosis: randomised placebo-controlled double-blind trial.

BACKGROUND: To determine if oral metronidazole (MTZ-400 mg bid) with 2% vaginal clindamycin-cream (Clind) or a Lactobacillus acidophilus vaginal-probiotic containing oestriol (Prob) reduces 6-month bacterial vaginosis (BV) recurrence. METHODS: Double-blind placebo-controlled parallel-group single-site study with balanced randomization (1:1:1) conducted at Melbourne Sexual Health Centre, Australia. Participants with symptomatic BV [Nugent Score (NS) = 7-10 or ≥3 Amsel's criteria and NS = 4-10], were randomly allocated to MTZ-Clind, MTZ-Prob or MTZ-Placebo and assessed at 1,2,3 and 6 months. MTZ and Clind were administered for 7 days and Prob and Placebo for 12 days. Primary outcome was BV recurrence (NS of 7-10) on self-collected vaginal-swabs over 6-months. Cumulative BV recurrence rates were compared between groups by Chi-squared statistics. Kaplan-Meier, log rank and Cox regression analyses were used to compare time until and risk of BV recurrence between groups. RESULTS: 450 18-50 year old females were randomized and 408 (91%), equally distributed between groups, provided ≥1 NS post-randomization and were included in analyses; 42 (9%) participants with no post-randomization data were excluded. Six-month retention rates were 78% (n = 351). One-month BV recurrence (NS 7-10) rates were 3.6% (5/140), 6.8% (9/133) and 9.6% (13/135) in the MTZ-Clind, MTZ-Prob and MTZ-Placebo groups respectively, p = 0.13. Hazard ratios (HR) for BV recurrence at one-month, adjusted for adherence to vaginal therapy, were 0.43 (95%CI 0.15-1.22) and 0.75 (95% CI 0.32-1.76) in the MTZ-Clind and MTZ-Prob groups compared to MTZ-Plac respectively. Cumulative 6-month BV recurrence was 28.2%; (95%CI 24.0-32.7%) with no difference between groups, p = 0.82; HRs for 6-month BV recurrence for MTZ-Clind and MTZ-Prob compared to MTZ-Plac, adjusted for adherence to vaginal therapy were 1.09(95% CI = 0.70-1.70) and 1.03(95% CI = 0.65-1.63), respectively. No serious adverse events occurred. CONCLUSION: Combining the recommended first line therapies of oral metronidazole and vaginal clindamycin, or oral metronidazole with an extended-course of a commercially available vaginal-L.acidophilus probiotic, does not reduce BV recurrence. TRIAL REGISTRATION: ANZCTR.org.au ACTRN12607000350426.

Patterns of treatment of external genital warts in Australian sexual health clinics.

BACKGROUND: External genital warts are a common sexually transmitted viral disease. We describe the patterns of treatment for initial presentations of external genital warts (EGWs) in Australian sexual health centers. METHODS: This was a retrospective audit of 489 case notes from consecutive individuals who presented with a new diagnosis of EGWs to 1 of 5 major sexual health clinics in Australia. Eligibility criteria were consecutive patients aged 18 to 45 years inclusively, presenting with first ever episode of EGWs from January 1, 2004. Exclusion criteria were patients who were immunocompromised, including HIV infection, or enrollment in a treatment study for EGWs. RESULTS: The median age at presentation of women was 23.2 years and of men 26.8 years. One quarter (n = 127) of patients had another sexually transmitted infection diagnosed at presentation. Nearly half of the patients (n = 224) presented only once for treatment. Most often, patients were treated with a monotherapy (n = 382/489; 78%), usually cryotherapy (257; 53%). Staff applied treatment in 361 (74%) cases. There was wide variation across sites, possibly reflecting local policies and budgets. We found no difference in wart resolution (n = 292; 60%) by initial treatment chosen. CONCLUSIONS: The diagnosis and treatment of genital warts constitute a sizable proportion of clinical visits to the audited sexual health services and require a large input of staff time to manage, including the application of topical treatments. Our results help complete the picture of the burden of EGWs on Australian sexual health centers before the introduction of the HPV vaccine.