The evolutionary history of Drosophila simulans Y chromosomes reveals molecular signatures of resistance to sex ratio meiotic drive

The recent evolutionary history of the Y chromosome in Drosophila simulans, a worldwide species of Afrotropical origin, is closely linked to that of X-linked meiotic drivers (Paris system). The spread of the Paris drivers in natural populations has elicited the selection of drive resistant Y chromosomes. To infer the evolutionary history of the Y chromosome in relation to the Paris drive, we sequenced 21 iso-Y lines, each carrying a Y chromosome from a different location. Among them, 13 lines carry a Y chromosome that is able to counteract the effect of the drivers. Despite their very different geographical origins, all sensitive Y's are highly similar, suggesting that they share a recent common ancestor. The resistant Y chromosomes are more divergent and segregate in four distinct clusters. The phylogeny of the Y chromosome confirms that the resistant lineage predates the emergence of Paris drive. The ancestry of the resistant lineage is further supported by the examination of Y-linked sequences in the sister species of D. simulans, D. sechellia, and D. mauritiana. We also characterized the variation in repeat content among Y chromosomes and identified multiple simple satellites associated with resistance. Altogether, the molecular polymorphism allows us to infer the demographic and evolutionary history of the Y chromosome and provides new insights on the genetic basis of resistance.

HCV cure: an appropriate moment to reduce cannabis use in people living with HIV? (ANRS CO13 HEPAVIH data)

BACKGROUND

Thanks to direct-acting antivirals, hepatitis C virus (HCV) infection can be cured, with similar rates in HCV-infected and HIV-HCV co-infected patients. HCV cure is likely to foster behavioral changes in psychoactive substance use, which is highly prevalent in people living with HIV (PLWH). Cannabis is one substance that is very commonly used by PLWH, sometimes for therapeutic purposes. We aimed to identify correlates of cannabis use reduction following HCV cure in HIV-HCV co-infected cannabis users and to characterize persons who reduced their use.

METHODS

We used data collected on HCV-cured cannabis users in a cross-sectional survey nested in the ANRS CO13 HEPAVIH cohort of HIV-HCV co-infected patients, to perform logistic regression, with post-HCV cure cannabis reduction as the outcome, and socio-behavioral characteristics as potential correlates. We also characterized the study sample by comparing post-cure substance use behaviors between those who reduced their cannabis use and those who did not.

RESULTS

Among 140 HIV-infected cannabis users, 50 and 5 had reduced and increased their use, respectively, while 85 had not changed their use since HCV cure. Cannabis use reduction was significantly associated with tobacco use reduction, a decrease in fatigue level, paying more attention to one's dietary habits since HCV cure, and pre-HCV cure alcohol abstinence (p = 0.063 for alcohol use reduction).

CONCLUSIONS

Among PLWH using cannabis, post-HCV cure cannabis reduction was associated with tobacco use reduction, improved well-being, and adoption of healthy behaviors. The management of addictive behaviors should therefore be encouraged during HCV treatment.

1146 Interaction Of Mild Cognitive Impairment And Late-life Depression In Actigraphy And Self Report Of Sleep Problems

Introduction

Late-life depression has been proposed as a precursor to amnestic Mild Cognitive Impairment (aMCI), the prodrome of Alzheimer’s disease. Both conditions are associated with sleep and cognitive problems. We hypothesized that MCI and current depressive symptoms would co-occur more frequently, but express distinct sleep phenotypes.

Methods

Independently living older adults (N=80), age 62-90 (M=71.78, SD=5.98), were recruited from a geriatric psychiatry clinic and the community for a home sleep study. A clinical decision board and neurocognitive battery were used to determine MCI status. Participants completed the CES-D and depression history interview where endorsement of current depression was considered positive. Sleep was examined with wrist actigraphy for 7 days. Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Stanford Sleepiness Scale (SSS) provided subjective sleep quality.

Results

Based on these criteria, 41.2% of the sample were determined to be MCI (n=33); the remainder were deemed normative for age (NC; n=47). Chi-square analyses showed a higher frequency of MCI were positive for current depression than expected (14.2%; p=0.017). Repeated-measures MANOVA, using current depression symptoms and MCI as factors, revealed MCI was associated with longer sleep latency (p=0.035) and wake bout time (p=0.039); whereas, current depression was associated with longer sleep latency, more fragmentation/WASO, and lower sleep efficiency (p’s<0.05), self-report of poorer daytime dysfunction (p=0.005), and greater daytime sleepiness (p=0.001). MCI x current depression interactions were found for sleep latency (p=0.029); and PSQI sleep disturbances (p=0.005) and sleep medication (p=0.025).

Conclusion

Despite distinct sleep disordered phenotypes, the interaction of MCI and current depression is associated with delayed sleep onset, use sleep medication and report of sleep disturbances.

Support

This project was sponsored by: NASA, Maine Space Consortium; AG 056176, AG 053164 Vice President for Research, U. Maine; Maine Technology Institute; DoD Phase I SBIR and R44AG059536-01 SBIR Phase II Award.

P5341Predictive factors of atherosclerotic cardiovascular diseases events in HIV-HVC co-infected patients: results from hepavih ANRS co13 cohort

Introduction

Several studies highlighted an increased risk of cardiovascular disease (CVD) in HIV-HCV co-infected patients without clearly identifying specific virologic factors associated with atherosclerotic CVD (ASCVD) events.

Purpose

Hence, we analyzed data collection from the French nationwide ANRS CO13 HEPAVIH cohort to determine the incidence of ASCVD events in HIV-HCV co-infected patients and the predictive factors associated with its occurrence.

Methods

The French multicenter nationwide ANRS CO13 HEPAVIH clinic-based cohort collected prospective clinical and biological data from HIV-HCV co-infected patients followed-up in 28 different university hospitals between December 2005 to November 2016. Participants with at least one year of follow-up were included. Primary outcome was the occurrence of major ASCVD events (cardiovascular death, acute coronary syndrome, coronary revascularization and stroke). Secondary outcomes were total ASCVD events including major ASCVD events and minor ASCVD events (peripheral arterial disease [PAD]). Incidence rates were estimated using Aalen-Johansen method and factors associated with ASCVD identified with Cox proportional hazards models.

Results

A total of 1213 patients were included: median age 45.4 years [42.1–49.0], 70.3% men, current smoking 70.2%, overweight 19.5%, liver cirrhosis 18.9%, chronic alcohol consumption 7.8%, diabetes mellitus (5.9%), personal history of CVD 2.7%, and statins use 4.1%. After a median follow-up of 5.1 years [3.9–7.0], 44 participants experienced at least one ASCVD event (26 major ASCVD event, and 20 a minor event). Incidences for total, major and minor ASCVD events were of 6.98 [5.19; 9.38], 4.01 [2.78; 6.00], and 3.17 [2.05; 4.92] per 1000 person-years, respectively. Personal history of CVD (Hazard Ratio (HR)=13.94 [4.25–45.66]), high total cholesterol (HR=1.63 [1.24–2.15]), low HDL cholesterol (HR=0.08 [0.02–0.34]) and undetectable HIV viral load (HR=0.41 [0.18–0.96]) were identified as independent factors associated with major ASCVD events while cirrhosis status, liver fibrosis and HCV sustained viral response were not.

Cumulative incidence of CV events

Conclusion

HIV-HCV co-infected patients experience a high incidence of ASCVD events both coronary and peripheral artery diseases. Traditional CV risk factors are the main determinants of ASCVD whereas undetectable HIV viral load seems to be protective. Management of cholesterol abnormalities and controlling viral load are essential to modify this high cardiovascular risk.

Acknowledgement/Funding

Agence Natoinale de Recherche sur le SIDA et les Hépatites virales

The aza-Michael reaction: towards semi-crystalline polymers from renewable itaconic acid and diamines

This paper reports, for the first time, semi-crystalline polymers based on bis-pyrrolidone dicarboxylic acids (BPDA) obtained from the aza-Michael reaction between renewable itaconic acid and various diamines.

Investigation of risk factors for mortality in aged guide dogs: A retrospective cohort study

The overall median lifespan of domestic dogs has been estimated to 9-12 years, but little is known about risk factors for mortality in aged and a priori healthy dogs. The objective of this retrospective cohort study was to determine which characteristics are associated with mortality in aged and a priori healthy guide dogs, in a retrospective cohort study of 116 guide dogs followed from a systematic geriatric examination at the age of 8-10 years old. A geriatric grid collected the clinical data and usual biological parameters were measured at the time of examination. Univariate (Kaplan-Meier estimates) and multivariable (Cox proportional hazard model) survival analyses were used to assess the associations with time to all-cause death. The majority of dogs were Golden Retrievers (n=48) and Labrador Retrievers (n=27). Median age at geriatric examination was 8.9 years. A total of 76 dogs died during follow-up, leading to a median survival time from geriatric examination of 4.4 years. After adjustment for demographic and biological variables, an increased alanine amionotransferase level (adjusted Hazard Ratio (adjusted HR), 6.2; 95% confidence interval [95%CI], 2.0-19.0; P<0.01), presenting skin nodules (adjusted HR, 1.9; 95% CI, 1.0-3.4; P=0.04), and not being a Labrador Retriever (adjusted HR, 3.3; 95%CI, 1.4-10; P<0.01) were independently associated with a shorter time to death. This study documents independent associations of alanine aminotransferase level, skin nodules and breed with mortality in aged guide dogs. These results may be useful for preventive medical care when conducting a geriatric examination in working dogs.

Systemic cobalt toxicity from total hip arthroplasties

As adverse events related to metal on metal hip arthroplasty have been better understood, there has been increased interest in toxicity related to the high circulating levels of cobalt ions. However, distinguishing true toxicity from benign elevations in cobalt levels can be challenging. The purpose of this review is to examine the use of cobalt alloys in total hip arthroplasty, to review the methods of measuring circulating cobalt levels, to define a level of cobalt which is considered pathological and to review the pathophysiology, risk factors and treatment of cobalt toxicity. To the best of our knowledge, there are 18 published cases where cobalt metal ion toxicity has been attributed to the use of cobalt-chromium alloys in hip arthroplasty. Of these cases, the great majority reported systemic toxic reactions at serum cobalt levels more than 100 μg/L. This review highlights some of the clinical features of cobalt toxicity, with the goal that early awareness may decrease the risk factors for the development of cobalt toxicity and/or reduce its severity.

Take home message: Severe adverse events can arise from the release of cobalt from metal-on-metal arthroplasties, and as such, orthopaedic surgeons should not only be aware of the presenting problems, but also have the knowledge to treat appropriately.

Cite this article: Bone Joint J 2016;98-B:14–20.

Systemic cobalt toxicity from total hip arthroplasties

Recently, the use of metal-on-metal articulations in total hip arthroplasty (THA) has led to an increase in adverse events owing to local soft-tissue reactions from metal ions and wear debris. While the majority of these implants perform well, it has been increasingly recognised that a small proportion of patients may develop complications secondary to systemic cobalt toxicity when these implants fail. However, distinguishing true toxicity from benign elevations in cobalt ion levels can be challenging.

The purpose of this two part series is to review the use of cobalt alloys in THA and to highlight the following related topics of interest: mechanisms of cobalt ion release and their measurement, definitions of pathological cobalt ion levels, and the pathophysiology, risk factors and treatment of cobalt toxicity. Historically, these metal-on-metal arthroplasties are composed of a chromium-cobalt articulation.

The release of cobalt is due to the mechanical and oxidative stresses placed on the prosthetic joint. It exerts its pathological effects through direct cellular toxicity.

This manuscript will highlight the pathophysiology of cobalt toxicity in patients with metal-on-metal hip arthroplasties.

Take home message: Patients with new or evolving hip symptoms with a prior history of THA warrant orthopaedic surgical evaluation. Increased awareness of the range of systemic symptoms associated with cobalt toxicity, coupled with prompt orthopaedic intervention, may forestall the development of further complications.

Cite this article: Bone Joint J 2016;98-B:6–13.

HCV viral load at baseline and at week 4 of telaprevir/boceprevir based triple therapies are associated with virological outcome in HIV/hepatitis C co-infected patients

BACKGROUND

As first generation HCV-specific protease inhibitors, boceprevir (BOC) or telaprevir (TVR) can achieve 60% to 70% sustained virological response (SVR) for HCV infected patients with genotype 1 infections, they could remain temporary a therapeutic option in patients living in resources limited countries with limited access to the new anti-HCV direct acting antiviral (DAA) drugs, such as sofosbuvir.

OBJECTIVES AND STUDY DESIGN

Here we evaluated in a routine practice setting, the treatment responses, tolerance and factors associated with SVR of a triple therapy with BOC or TVR, combined with pegylated interferon and ribavirin (PegIFN/RBV) in HIV/HCV co-infected patients, included in a large cohort of HIV/HCV coinfected patients (ANRS CO13-HEPAVIH).

RESULTS

Among the 89 HIV/HCV coinfected patients treated, 65% of whom were previous non-responders to PegIFN/RBV therapy, 65%, 55% and 41% had at baseline genotype 1a, a high baseline HCV-RNA (≥800,000 IU/ml) and a cirrhosis, respectively. The SVR12 rate was 63% overall, 53% for BOC-based regimen and 66% for TVR-based regimen. In multivariate analysis, two factors were significantly associated with HCV SVR: HCV viral load <800,000 IU/mL at treatment initiation versus ≥800,000 IU/mL (OR 4.403, 95% CI 1.29-15.04; p=0.018) and virological response at W4 (HCV-RNA undetectable after 4 weeks of triple therapy) (OR 3.35, 95% CI 1.07-10.48; p=0.038).

CONCLUSIONS

Overall SVR12 was 63% and our results suggest that HIV/HCV coinfected patients with low HCV viral load (<800,000 IU/mL) and undetectable HCV-RNA after 4 weeks of triple therapy with TVR or BOC-based regimen have a higher probability of treatment success.

Endogenous hepadnaviruses, bornaviruses and circoviruses in snakes

We report the discovery of endogenous viral elements (EVEs) from Hepadnaviridae, Bornaviridae and Circoviridae in the speckled rattlesnake, Crotalus mitchellii, the first viperid snake for which a draft whole genome sequence assembly is available. Analysis of the draft assembly reveals genome fragments from the three virus families were inserted into the genome of this snake over the past 50 Myr. Cross-species PCR screening of orthologous loci and computational scanning of the python and king cobra genomes reveals that circoviruses integrated most recently (within the last approx. 10 Myr), whereas bornaviruses and hepadnaviruses integrated at least approximately 13 and approximately 50 Ma, respectively. This is, to our knowledge, the first report of circo-, borna- and hepadnaviruses in snakes and the first characterization of non-retroviral EVEs in non-avian reptiles. Our study provides a window into the historical dynamics of viruses in these host lineages and shows that their evolution involved multiple host-switches between mammals and reptiles.

Dynamic visual cues induce jaw opening and closing by tiger beetles during pursuit of prey

In dynamic locomotory contexts, visual cues often trigger adaptive behaviour by the viewer, yet studies investigating how animals determine impending collisions typically employ either stationary viewers or objects. Here, we describe a dynamic situation of visually guided prey pursuit in which both impending prey contact and escape elicit observable adaptive behaviours in the pursuer, a predatory beetle. We investigated which visual cues may independently control opening and closing of the beetle's jaws during chases of prey dummies. Jaw opening and closing typically occur when prey is within the 60° binocular field, but not at specific distances, angular sizes or time-to-collision. We show that a sign change in the expansion rate of the target image precedes jaw opening (16 ms) and closing (35 ms), signalling to the beetle that it is gaining on the target or that the target is getting away. We discuss the 'sloppiness' of such variation in the lag of the behavioural response, especially jaw closing, as an adaptation to uncertainty about target position due to degradation of the target image by motion blur from the fast-running beetle.

Tiger beetles pursue prey using a proportional control law with a delay of one half-stride

Tiger beetles are fast diurnal predators capable of chasing prey under closed-loop visual guidance. We investigated this control system using statistical analyses of high-speed digital recordings of beetles chasing a moving prey dummy in a laboratory arena. Correlation analyses reveal that the beetle uses a proportional control law in which the angular position of the prey relative to the beetle's body axis drives the beetle's angular velocity with a delay of about 28 ms. The proportionality coefficient or system gain, 12 s(-1), is just below critical damping. Pursuit simulations using the derived control law predict angular orientation during pursuits with a residual error of about 7°. This is of the same order of magnitude as the oscillation imposed by the beetle's alternating tripod gait, which was not factored into the control law. The system delay of 28 ms equals a half-stride period, i.e. the time between the touch down of alternating tripods. Based on these results, we propose a physical interpretation of the observed control law: to turn towards its prey, the beetle on average exerts a sideways force proportional to the angular position of the prey measured a half-stride earlier.

Static antennae act as locomotory guides that compensate for visual motion blur in a diurnal, keen-eyed predator

High visual acuity allows parallel processing of distant environmental features, but only when photons are abundant enough. Diurnal tiger beetles (Carabidae: Cicindelinae) have acute vision for insects and visually pursue prey in open, flat habitats. Their fast running speed causes motion blur that degrades visual contrast, forces stop-and-go pursuit and potentially impairs obstacle detection. We demonstrate here that vision is insufficient for obstacle detection during running, and show instead that antennal touch is both necessary and sufficient for obstacle detection. While running, tiger beetle vision appears to be photon-limited in a way reminiscent of animals in low-light habitats. Such animals often acquire wide-field spatial information through mechanosensation mediated by longer, more mobile appendages. We show that a nocturnal tiger beetle species waves its antennae in elliptical patterns typical of poorly sighted insects. While antennae of diurnal species are also used for mechanosensation, they are rigidly held forward with the tips close to the substrate. This enables timely detection of path obstructions followed by an increase in body pitch to avoid collision. Our results demonstrate adaptive mechanosensory augmentation of blurred visual information during fast locomotion, and suggest that future studies may reveal non-visual sensory compensation in other fast-moving animals.

Characteristics of major Escherichia coli reductases involved in aerobic nitro and azo reduction

AIMS

Escherichia coli is able to reduce azo compounds such as methyl red (MR) and nitro compounds such as 7-nitrocoumarin-3-carboxylic acid (7NCCA). The aim of this study was to clarify the specificity of the major E. coli reductases.

METHODS AND RESULTS

Enzymatic assays with pure enzymes obtained after cloning, overproduction and purification under native or denaturing conditions were performed on three enzymes: AzoR, NfsA and NfsB. Their dependence on putative cofactors such as flavin mononucleotide (FMN), NADH and NADPH was studied as well as the reductase capacity of E. coli mutants depleted for one, two or three of the corresponding genes.

CONCLUSIONS

AzoR was able to reduce both MR and 7NCCA, whereas NfsA and NfsB could only reduce the nitro compound. AzoR and NfsB were strictly FMN dependent in contrast to NfsA. At a low oxygen concentration, the three proteins were not mandatory for azo reduction and nitro reduction, but in optimal aerobic conditions, azoR was essential for MR reduction, and an nfsA/nfsB combination was important for 7NCCA reduction. Overexpression of azoR gene was able to compensate for the loss of nfsA and nfsB under aerobic conditions.

SIGNIFICANCE AND IMPACT OF STUDY

These data provide new insights into the substrate specificity of major E. coli nitroreductases and demonstrate that oxygen is an important parameter to take into account in studies of nitroreductase activity.

Emperor penguin body surfaces cool below air temperature

Emperor penguins Aptenodytes forsteri are able to survive the harsh Antarctic climate because of specialized anatomical, physiological and behavioural adaptations for minimizing heat loss. Heat transfer theory predicts that metabolic heat loss in this species will mostly depend on radiative and convective cooling. To examine this, thermal imaging of emperor penguins was undertaken at the breeding colony of Pointe Géologie in Terre Adélie (66°40' S 140° 01' E), Antarctica in June 2008. During clear sky conditions, most outer surfaces of the body were colder than surrounding sub-zero air owing to radiative cooling. In these conditions, the feather surface will paradoxically gain heat by convection from surrounding air. However, owing to the low thermal conductivity of plumage any heat transfer to the skin surface will be negligible. Future thermal imaging studies are likely to yield further insights into the adaptations of this species to the Antarctic climate.

Female acoustic reply to variation in the male call in a duetting katydid, Scudderia pistillata

Female phaneropterinae katydids (Orthoptera: Tettigoniidae) commonly reply to conspecific male attraction calls with a brief, broadband acoustic tick. In this paper we describe the complex interaction of the katydid Scudderia pistillata female tick response with the variation in male call, which comprises a bout of increasing length multisyllabic phrases. The female responds to each phrase in the bout with a variable number of ticks. She adjusts her tick response, ranging from 1 to 8, with the number of syllables the male presents, responding maximally to 7–9 syllables per phrase. Females reduce their number of ticks in response to later phrases when presented with to various manipulations of a male bout. By adjusting her ticks in response to variability in the male call, the female potentially provides information to the calling male on her preference for certain call characteristics. The temporal latency for the female to reply is not fixed, but is highly correlated with both the number of syllables she hears, as well as the number of ticks she produces.

Effects of antisense oligonucleotides targeting k-ras expression in pancreatic-cancer cell-lines

The K-ras oncogene is activated in more than 75% of pancreatic cancers and represents a compelling target for therapeutic intervention. We have examined the potential of K-ras antisense oligonucleotides in human pancreatic cancer cell lines. Dose-dependent antiproliferative effects are seen, but these do not correlate with reduced K-ras levels in the treated cells. Although patterns of uptake can be altered by treatment with cationic lipids, this does not enhance antiproliferative effects nor reduce K-ras expression. The antisense approach requires considerable development before useful anti-cancer agents can emerge and alternative approaches are needed for K-ras to be a target for genetic intervention therapy for human cancer.