Should screening for Chlamydia trachomatis and Neisseria gonorrhoeae in HIV-men who have sex with men be recommended?

INTRODUCTION Sexually transmitted infections (STI) like Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) have been associated with increased risk of HIV acquisition (1). It has been also described as a high prevalence of asymptomatic CT and NG infections in men who have sex with men (MSM) (2). The aim of this study was to know the prevalence of CT and/or NG infections in asymptomatic HIV-MSM and the related factors. MATERIALS AND METHODS Prospective study of a cohort of asymptomatic HIV-MSM with follow-up in Malaga (southern Spain) during October 2012-May 2014. Patients with an opportunistic event or who received active antibiotic therapy for CT and/or NG in the previous month were excluded. All of them completed a questionnaire about sexual behaviour, barrier methods and recreational drugs use. Demographical, epidemiological, clinical, analytical and therapeutic data were also collected. Pharyngeal and rectal swabs, and urine samples were collected to be tested for CT and NG by nucleic acid amplification test (c4800 CT/NG. Roche Diagnostics, Mannheim, Germany) (3). STATISTICS ANALYSIS SPSS 17.0. RESULTS 255 patients were asked to participate and 248 of them accepted. Median age was 37.7 (30.6-46.3) years, median time since HIV diagnosis was 47.7 (10.5-104.1) months, and median CD4 cells count was 607 (440-824) cell/µL. There were 195 (78.6%) patients on antiretroviral therapy; 81.5% of them had undetectable viral load. 80.5% of the patients had a past history of STI. Infection by CT and/or NG was diagnosed in 24 (9.7%) patients. Overall four urine samples, two pharyngeal, and 15 rectal ones were positive for CT, and five pharyngeal and five rectal swabs were positive for NG. Two patients were co-infected by CT and NG: one with CT in urine and both in rectum, another with CT in urine and rectum and NG in pharynx. One patient presented CT in pharynx and rectum, and two patients NG in pharynx and rectum. Positive CT and/or NG tests were only related with detectable HIV viral load (OR 3.08, 95% CI 1.2-7.4; p=0.01). It was not related with sexual behaviour, nor with alcohol or recreational drugs use. CONCLUSIONS STI screening had a great acceptance in this population. There was a high prevalence of asymptomatic CT and/or NG infections. Rectum sample was the most effective one. Viral suppression could protect from these STI. Screening should be recommended in HIV-MSM.

Fungal sex: meiosis machinery in ancient symbiotic fungi.

Arbuscular mycorrhizal fungi are important symbionts that enhance plant growth. They were thought to have been asexual for hundreds of millions of years. A new study reveals that the fungi actually possess highly conserved genetic machinery for completion of meiosis.

Advances in our understanding of mammalian sex-biased dispersal.

Sex-biased dispersal is an almost ubiquitous feature of mammalian life history, but the evolutionary causes behind these patterns still require much clarification. A quarter of a century since the publication of seminal papers describing general patterns of sex-biased dispersal in both mammals and birds, we review the advances in our theoretical understanding of the evolutionary causes of sex-biased dispersal, and those in statistical genetics that enable us to test hypotheses and measure dispersal in natural populations. We use mammalian examples to illustrate patterns and proximate causes of sex-biased dispersal, because by far the most data are available and because they exhibit an enormous diversity in terms of dispersal strategy, mating and social systems. Recent studies using molecular markers have helped to confirm that sex-biased dispersal is widespread among mammals and varies widely in direction and intensity, but there is a great need to bridge the gap between genetic information, observational data and theory. A review of mammalian data indicates that the relationship between direction of sex-bias and mating system is not a simple one. The role of social systems emerges as a key factor in determining intensity and direction of dispersal bias, but there is still need for a theoretical framework that can account for the complex interactions between inbreeding avoidance, kin competition and cooperation to explain the impressive diversity of patterns.

Using parthenogenetic lineages to identify advantages of sex

The overwhelming predominance of sexual reproduction in nature is surprising given that sex is expected to confer profound costs in terms of production of males and the breakup of beneficial allele combinations. Recognition of these theoretical costs was the inspiration for a large body of empirical research-typically focused on comparing sexual and asexual organisms, lineages, or genomes-dedicated to identifying the advantages and maintenance of sex in natural populations. Despite these efforts, why sex is so common remains unclear. Here, we argue that we can generate general insights into the advantages of sex by taking advantage of parthenogenetic taxa that differ in such characteristics as meiotic versus mitotic offspring production, ploidy level, and single versus multiple and hybrid versus non-hybrid origin. We begin by evaluating benefits that sex can confer via its effects on genetic linkage, diversity, and heterozygosity and outline how the three classes of benefits make different predictions for which type of parthenogenetic lineage would be favored over others. Next, we describe the type of parthenogenetic model system (if any) suitable for testing whether the hypothesized benefit might contribute to the maintenance of sex in natural populations, and suggest groups of organisms that fit the specifications. We conclude by discussing how empirical estimates of characteristics such as time since derivation and number of independent origins of asexual lineages from sexual ancestors, ploidy levels, and patterns of molecular evolution from representatives of these groups can be used to better understand which mechanisms maintain sex in natural populations.

The role of polymerase chain reaction of high-risk human papilloma virus in the screening of high-grade squamous intraepithelial lesions in the anal mucosa of human immunodeficiency virus-positive males having sex with males.

OBJECTIVES To evaluate the advantages of cytology and PCR of high-risk human papilloma virus (PCR HR-HPV) infection in biopsy-derived diagnosis of high-grade squamous intraepithelial lesions (HSIL = AIN2/AIN3) in HIV-positive men having sex with men (MSM). METHODS This is a single-centered study conducted between May 2010 and May 2014 in patients (n = 201, mean age 37 years) recruited from our outpatient clinic. Samples of anal canal mucosa were taken into liquid medium for PCR HPV analysis and for cytology. Anoscopy was performed for histology evaluation. RESULTS Anoscopy showed 33.8% were normal, 47.8% low-grade squamous intraepithelial lesions (LSIL), and 18.4% HSIL; 80.2% had HR-HPV. PCR of HR-HPV had greater sensitivity than did cytology (88.8% vs. 75.7%) in HSIL screening, with similar positive (PPV) and negative predictive value (NPV) of 20.3 vs. 22.9 and 89.7 vs. 88.1, respectively. Combining both tests increased the sensitivity and NPV of HSIL diagnosis to 100%. Correlation of cytology vs. histology was, generally, very low and PCR of HR-HPV vs. histology was non-existent (<0.2) or low (<0.4). Area under the receiver operating characteristics (AUROC) curve analysis of cytology and PCR HR-HPV for the diagnosis of HSIL was poor (<0.6). Multivariate regression analysis showed protective factors against HSIL were: viral suppression (OR: 0.312; 95%CI: 0.099-0.984), and/or syphilis infection (OR: 0.193; 95%CI: 0.045-0.827). HSIL risk was associated with HPV-68 genotype (OR: 20.1; 95%CI: 2.04-197.82). CONCLUSIONS When cytology and PCR HR-HPV findings are normal, the diagnosis of pre-malignant HSIL can be reliably ruled-out in HIV-positive patients. HPV suppression with treatment protects against the appearance of HSIL.

NADPH-diaphorase-positive ganglion cells of the rat adrenal gland: age- and sex-related changes in their number, size, and distribution.

The rat adrenal gland contains ganglion cells able to synthesize nitric oxide (NO). This messenger molecule controls and modulates adrenal secretory activity and blood flow. The present study analyzed the number, size, and distribution of NO-producing adrenal neurons in adulthood and during postnatal development by means of beta-nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry. This method reliably visualizes the enzyme responsible for NO generation. The reactive neurons per adrenal gland were 350-400 in both male and female adult rats. The positive nerve cell bodies were mostly located in the medulla, few being detected within the cortex and the subcapsular region. Dual labeling with anti-microtubule-associated protein 2 antibody, specific for neuronal elements, confirmed this distribution. Anti-microtubule-associated protein 1b antibody identified a subset of NADPH-d-positive neurons, displaying different degrees of maturation according to their position within the adrenal gland. At birth, there were about 220 NADPH-d-labeled neurons per adrenal gland in both sexes. As confirmed by dual immunocytochemical labeling, their great majority was evenly distributed between the cortex and the subcapsular region, the medulla being practically devoid of stained neurons. After birth, the number of adrenal NADPH-d-positive ganglion cells displayed a strong postnatal increase and reached the adult-like distribution after 1-2 months. During the period of increase, there was a transient difference in the numbers of these cells in the two sexes. Thus we present here evidence of plasticity in the number, size, and distribution of NADPH-d-positive adrenal neurons between birth and adulthood; in addition, we describe transient sex-related differences in their number and distribution during the 2nd postnatal week, which are possibly related to the epigenetic action of gonadal hormones during this period.

1.° P. Ovidii Nasonis amorum libri tres. — 2.° Ejusdem liber de remedio amoris. — 3.° Ejusdem carmen de pulice. — 4.° Ejusdem fastorum libri sex.

Puteanus

Auli Persii Flacci satyrae sex : passim inter lineas glossae et ad marginem scholia ; praemittuntur authoris vita, et argumentum in quo de satyra disseritur.

Colbertinus

1.° Papinii Statii sylvarum libri quinque : finis quinti desideratur. — 2.° Ejusdem Achilleïdos libri duo : secundi finis desideratur. — 3.° Auli Persii Flacci satyrae sex, cum scholiis. — 4.° Sallustii in Ciceronem declamatio, cum hujus responso. — 5.° Rogerii epistola ad Joannem Maludanum, regium apud Lemovicas Patronum. — 6.° Ovidii fragmenta.

Mentellianus

Role of Age and Sex in the Diagnosis of Early-stage Malignant Melanoma: A Cross-Sectional study.

Age and sex have been identified as predictors of outcome in malignant melanoma (MM). This aim of this multicentre, cross-sectional study was to analyse the role of age and sex as explanatory variables for the diagnosis of thin MM. A total of 2430 patients with MM were recruited. Cases of in situ-T1 MM were more frequent than T2-T4 MM (56.26% vs. 43.74%). Breslow thickness increased throughout decades of life (analysis of variance (ANOVA) p < 0.001), with a weak correlation between Breslow thickness and patient's age (r   = 0.202, p < 0.001). Breslow thickness was significantly less in women (1.79 vs. 2.38 mm, p = 0.0001). Binary logistic regression showed a significant (p < 0.001) odds ratio for age 0-29 years (1.18), and 30-59 years (1.16), and for women (1.09). Age and sex explained 3.64% of the variation observed in Tis-T1 frequency (R2 = 0.0364). Age and sex appear to explain a low percentage of the variation in the early detection of MM.

Comportamiento anticonceptivo en estudiantes universitarios y riesgo de infección con el virus de inmunodeficiencia humana (VIH)

Se examinan los comportamientos anticonceptivos de 225 jóvenes universitarios (22'7% hombres y 77'3% mujeres) con el objetivo de conocer su eficacia para evitar embarazos no deseados, SIDA y otras enfermedades de transmisión sexual (ETS). Se recogió información sobre los diferentes métodos anticonceptivos empleados por los sujetos con su última pareja, sin establecer ningún límite temporal. La mitad de los estudiantes no habían tenido nunca relaciones sexuales completas. La mitad de las conductas heterosexuales de los jóvenes sexualmente activos fueron adecuadas para protegerse frente al SIDA, otras ETS y embarazos no deseados (usar siempre preservativo); un tercio de las conductas únicamente eran útiles para evitar embarazos (píldora anticonceptiva) y las restantes (usar ocasionalmente el preservativo o el coitus interruptus ) les pusieron en riesgo frente a los tres problemas. Además, conforme se eleva la edad o el número de parejas de los estudiantes, es más frecuente el uso de píldoras anticonceptivas y menos probable el empleo de preservativo. Estos resultados sugieren que los estudiantes sexualmente activos están más interesados en la prevención de los embarazos no deseados que en evitar infectarse con el SIDA u otras ETS, por lo que seria conveniente promocionar entre ellos el uso del preservativo como método anticonceptivo, destacando sus ventajas frente a la píldora

Between-year variation in population sex ratio increases with complexity of the breeding system in Hymenoptera.

While adaptive adjustment of sex ratio in the function of colony kin structure and food availability commonly occurs in social Hymenoptera, long-term studies have revealed substantial unexplained between-year variation in sex ratio at the population level. In order to identify factors that contribute to increased between-year variation in population sex ratio, we conducted a comparative analysis across 47 Hymenoptera species differing in their breeding system. We found that between-year variation in population sex ratio steadily increased as one moved from solitary species, to primitively eusocial species, to single-queen eusocial species, to multiple-queen eusocial species. Specifically, between-year variation in population sex ratio was low (6.6% of total possible variation) in solitary species, which is consistent with the view that in solitary species, sex ratio can vary only in response to fluctuations in ecological factors such as food availability. In contrast, we found significantly higher (19.5%) between-year variation in population sex ratio in multiple-queen eusocial species, which supports the view that in these species, sex ratio can also fluctuate in response to temporal changes in social factors such as queen number and queen-worker control over sex ratio, as well as factors influencing caste determination. The simultaneous adjustment of sex ratio in response to temporal fluctuations in ecological and social factors seems to preclude the existence of a single sex ratio optimum. The absence of such an optimum may reflect an additional cost associated with the evolution of complex breeding systems in Hymenoptera societies.

Within-population polymorphism of sex-determination systems in the common frog (Rana temporaria).

In sharp contrast with birds and mammals, the sex chromosomes of ectothermic vertebrates are often undifferentiated, for reasons that remain debated. A linkage map was recently published for Rana temporaria (Linnaeus, 1758) from Fennoscandia (Eastern European lineage), with a proposed sex-determining role for linkage group 2 (LG2). We analysed linkage patterns in lowland and highland populations from Switzerland (Western European lineage), with special focus on LG2. Sibship analyses showed large differences from the Fennoscandian map in terms of recombination rates and loci order, pointing to large-scale inversions or translocations. All linkage groups displayed extreme heterochiasmy (total map length was 12.2 cM in males, versus 869.8 cM in females). Sex determination was polymorphic within populations: a majority of families (with equal sex ratios) showed a strong correlation between offspring phenotypic sex and LG2 paternal haplotypes, whereas other families (some of which with female-biased sex ratios) did not show any correlation. The factors determining sex in the latter could not be identified. This coexistence of several sex-determination systems should induce frequent recombination of X and Y haplotypes, even in the absence of male recombination. Accordingly, we found no sex differences in allelic frequencies on LG2 markers among wild-caught male and female adults, except in one high-altitude population, where nonrecombinant Y haplotypes suggest sex to be entirely determined by LG2. Multifactorial sex determination certainly contributes to the lack of sex-chromosome differentiation in amphibians.

Ever-young sex chromosomes in European tree frogs.

Non-recombining sex chromosomes are expected to undergo evolutionary decay, ending up genetically degenerated, as has happened in birds and mammals. Why are then sex chromosomes so often homomorphic in cold-blooded vertebrates? One possible explanation is a high rate of turnover events, replacing master sex-determining genes by new ones on other chromosomes. An alternative is that X-Y similarity is maintained by occasional recombination events, occurring in sex-reversed XY females. Based on mitochondrial and nuclear gene sequences, we estimated the divergence times between European tree frogs (Hyla arborea, H. intermedia, and H. molleri) to the upper Miocene, about 5.4-7.1 million years ago. Sibship analyses of microsatellite polymorphisms revealed that all three species have the same pair of sex chromosomes, with complete absence of X-Y recombination in males. Despite this, sequences of sex-linked loci show no divergence between the X and Y chromosomes. In the phylogeny, the X and Y alleles cluster according to species, not in groups of gametologs. We conclude that sex-chromosome homomorphy in these tree frogs does not result from a recent turnover but is maintained over evolutionary timescales by occasional X-Y recombination. Seemingly young sex chromosomes may thus carry old-established sex-determining genes, a result at odds with the view that sex chromosomes necessarily decay until they are replaced. This raises intriguing perspectives regarding the evolutionary dynamics of sexually antagonistic genes and the mechanisms that control X-Y recombination.