Interactive and Long-term Effects of Yolk Androgens and Antioxidants in Birds

This is the author accepted manuscript. The final version is available from OUP via the DOI in this recordPoster abstract - Annual Meeting of the Society-for-Integrative-and-Comparative-Biology (SICB), 4-8 January 2017, New Orleans, US

Long-term effect of yolk carotenoid levels on testis size in a precocial bird

This is the author accepted manuscript. The final version is available from the Royal Society via the DOI in this record.Conditions experienced during prenatal development can have long-lasting organizational effects on offspring. Maternal carotenoids deposited in the eggs of birds and other oviparous species play an important role during fast embryonic growth and chick development through their antioxidant properties. However, the long-term consequences of variation in maternal carotenoid transfer for the offspring have seldom been considered. Since plasma carotenoid levels at adulthood are known to influence testis size and yolk carotenoid levels influence the ability to extract carotenoids later in life, we hypothesized that maternally transmitted carotenoids might influence gonad size at adulthood. Here, we showed that male Japanese quail (Coturnix japonica) originating from a carotenoid-enriched egg had smaller testes than control individuals at adulthood. This result shows that yolk carotenoids have long-term organizational effects. In addition, given that carotenoid intake at sexual maturity increases sperm quality and that a decreased testis size is associated with a lower sperm production, we propose that carotenoid exposure during embryo development might influence a trade-off between ejaculate size and sperm quality.The study was supported by the Swiss National Science Foundation (PP00P3_128386 and PP00P3_157455) and the Fonds zur Förderung des akademischen Nachwuchses

Glacial-interglacial vegetation dynamics in South Eastern Africa coupled to sea surface temperature variations in the Western Indian Ocean

Glacial-interglacial fluctuations in the vegetation of South Africa might elucidate the climate system at the edge of the tropics between the Indian and Atlantic Oceans. However, vegetation records covering a full glacial cycle have only been published from the eastern South Atlantic. We present a pollen record of the marine core MD96-2048 retrieved by the Marion Dufresne from the Indian Ocean similar to 120 km south of the Limpopo River mouth. The sedimentation at the site is slow and continuous. The upper 6 m (spanning the past 342 Ka) have been analysed for pollen and spores at millennial resolution. The terrestrial pollen assemblages indicate that during interglacials, the vegetation of eastern South Africa and southern Mozambique largely consisted of evergreen and deciduous forests. During glacials open mountainous scrubland dominated. Montane forest with Podocarpus extended during humid periods was favoured by strong local insolation. Correlation with the sea surface temperature record of the same core indicates that the extension of mountainous scrubland primarily depends on sea surface temperatures of the Agulhas Current. Our record corroborates terrestrial evidence of the extension of open mountainous scrubland (including fynbos-like species of the high-altitude Grassland biome) for the last glacial as well as for other glacial periods of the past 300 Ka

In ovo yolk carotenoid and testosterone levels interactively influence female transfer of yolk antioxidants to her eggs

This is the author accepted manuscript. The final version is available from the Royal Society via the DOI in this recordMothers can influence prenatal conditions by varying the amount of nutrients, hormones or antioxidants they provide to their developing young. Some of these substances even affect the transfer of these compounds in the next generation, but it is less clear how different maternally transmitted compounds interact with each other to shape reproductive resource allocation in their offspring. Here, we found that female Japanese quail that were exposed to high carotenoid levels during embryonic development transferred lower concentrations of yolk antioxidants to their own eggs later in life. This effect disappeared, when both testosterone and carotenoid concentrations were manipulated simultaneously, showing long-term and interactive effects of these maternally derived egg components on a female’s own egg composition. Given that exposure to high levels of testosterone during embryo development stimulates the production of reactive oxygen (ROS) and impairs antioxidant defenses, we propose that carotenoids act as in-ovo antioxidants in an oxidatively stressful environment (i.e. when levels of testosterone are high) but might have prooxidant properties in an environment where they are not used to counteract an increased production of ROS. In line with this hypothesis, we previously showed that prenatal exposure to increased concentrations of yolk carotenoids leads to a rise of oxidative damage at adulthood, but only when yolk testosterone concentrations were not experimentally increased as well. As a consequence, antioxidants in the body may be used to limit oxidative damage in females exposed to high levels of carotenoids during development (but not in females exposed to increased levels of both carotenoids and testosterone), resulting in lower amounts of antioxidants being available for deposition into eggs. Since prenatal antioxidant exposure is known to influence fitness-related traits, the effect detected in this study might have transgenerational consequences.The study was supported by the Swiss National Science Foundation (PP00P3_128386 and PP00P3_157455) and the Fonds zur Förderung des akademischen Nachwuchses

Matrilineal inheritance of a key mediator of prenatal maternal effects

This is the author accepted manuscript. The final version is available from the Royal Society via the DOI in this record.Sex-linkage is predicted to evolve in response to sex-specific or sexually antagonistic selection. In line with this prediction, most sex-linked genes are associated with reproduction in the respective sex. In addition to traits directly involved in fertility and fecundity, mediators of maternal effects may be predisposed to evolve sex-linkage, because they indirectly affect female fitness through their effect on offspring phenotype. Here, we test for sex-linked inheritance of a key mediator of prenatal maternal effects in oviparous species, the transfer of maternally derived testosterone to the eggs. Consistent with maternal inheritance, we found that in Japanese quail (Coturnix japonica) granddaughters resemble their maternal (but not their paternal) grandmother in yolk testosterone deposition. This pattern of resemblance was not due to non-genetic priming effects of testosterone exposure during prenatal development, as an experimental manipulation of yolk testosterone levels did not affect the females' testosterone transfer to their own eggs later in life. Instead, W chromosome and/or mitochondrial variation may underlie the observed matrilineal inheritance pattern. Ultimately, the inheritance of mediators of maternal effects along the maternal line will allow for a fast and direct response to female-specific selection, thereby affecting the dynamics of evolutionary processes mediated by maternal effects.The study was financially supported by Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (PP00P3_128386 and PP00P3_157455) and Fonds zur Förderung des akademischen Nachwuchses (FAN)

Characterization of Susceptibility Artifacts in MR-thermometry PRFS-based during Laser Interstitial Thermal Therapy

Magnetic Resonance Thermometry (MRT) is demonstrating huge abilities to guide laser interstitial thermal therapy (LITT) in several organs, such as the brain. Among the methods to perform MRT, Proton Resonance Frequency (PRF) shift holds significant benefits, like tissue independence. Despite its potential, PRF shift-based MRT holds significant challenges affecting the accuracy of reconstructed temperature maps. In particular, susceptibility artifacts due to gas-bubble formation are an important source of error in temperature maps in MRT-guided LITT. This work presents the characterization of the susceptibility artifacts in MRT-guided LITT and the measurement of its size. LITT was performed in gelatin-based phantoms, at 5 W, 2 W, 1 W, and 0.5 W under MRI guidance with a 1.5 T clinical MRI scanner. Temperature images were obtained with a 3D EPI (Echo planar imaging) prototype sequence. Areas of temperature errors were defined as zones of negative temperature variation <-2 degrees C. Moreover, we have analyzed the artifact shape in sagittal, axial and coronal planes. The analysis demonstrates a double-lobe shape for the susceptibility artifact mainly distributed in the sagittal plane. Also, the higher laser power caused a bigger artifact area. Temperature errors of similar to 80 degrees C proved the necessity to avoid susceptibility artifact generation during MRT-guided LITT. The analysis of the influence of the laser power on the artifact has suggested that using low laser power (0.5 W) helps avoid this measurement error

Treatment of chronic hepatitis C in patients unresponsive to interferon. Interest of re-treatment combining interferon induction therapy and ribavirin (a multicenter pilot study)

Aim About 45% of patients with chronic hepatitis C are unresponsive to the present reference treatment combining pegelated interferon plus ribavirin; before pegylated interferon was available the non-response rate was around 60%. This open multicenter pilot study, initiated before pegylated interferon became available, was designed to evaluate, in patients unresponsive to interferon monotherapy, the rate of biological and virological response and side-effects of the ribivirin- alpha 2b interferon combination. Methods The combination protocol was ribavirin (1 to 1.2 g/d) plus alpha 2b interferon at induction doses (9 MU/d the first week; 4.5 MU/d the eleven following weeks; 3 MU/2 days the 36 following weeks). Results Among the 27 included patients, 17 (63%) were viremia-negative (PCR) after 12 weeks of treatment, 9 (33%) were complete responders (undetectable viremia and normal transaminases) at the end of treatment (48 weeks) and of follow-up (72 weeks). Patients with non-1, non-4 genotypes who derived full benefit from this therapeutic strategy (6/7 (86%) were complete responders: 4/5 with genotype 3 and 2/2 with genotype 5). Quality-of-life was impaired during treatment, especially during the first 12 weeks of high-dose interferon therapy. Conclusion While waiting for new therapeutic possibilities, these good results suggest interferon induction at the beginning of treatment remains a valid option

Timeline cluster: a graphical tool to identify risk of bias in cluster randomised trials

Robust evidence of the effectiveness of interventions relating to policy, practice, and organisation of healthcare often comes from well conducted cluster randomised trials. Such trials are, however, prone to recruitment bias depending on whether participants are recruited before the randomisation of clusters and whether the recruiter is blinded to the allocation status. In most cases, participants and trial staff cannot be blinded to the intervention, which might lead to performance and detection bias. Unfortunately, cluster trial reports often do not provide a clear description of the timing of trial processes and blinding, and these aspects are not covered by current reporting tools. This article proposes a graphical tool depicting the time sequence of steps and blinding status in cluster randomised trials. The tool might be helpful at both the protocol and the report writing stages to clarify the process and to help identify potential bias in cluster randomised trials

Cluster over individual randomization: are study design choices appropriately justified? Review of a random sample of trials

Taljaard, M., Goldstein, C. E., Giraudeau, B., Nicholls, S. G., Carroll, K., Hey, S. P., … Weijer, C. (2020). Cluster over individual randomization: are study design choices appropriately justified? Review of a random sample of trials. Clinical Trials. Copyright © The Author(s), 2020. DOI: https://doi.org/10.1177/174077451989679

A step towards stereotactic navigation during pelvic surgery: 3D nerve topography

Background: Long-term morbidity after multimodal treatment for rectal cancer is suggested to be mainly made up by nerve-injury-related dysfunctions. Stereotactic navigation for rectal surgery was shown to be feasible and will be facilitated by highlighting structures at risk of iatrogenic damage. The aim of this study was to investigate the ability to make a 3D map of the pelvic nerves with magnetic resonance imaging (MRI). Methods: A systematic review was performed to identify a main positional reference for each pelvic nerve and plexus. The nerves were manually delineated in 20 volunteers who were scanned with a 3-T MRI. The nerve identifiability rate and the likelihood of nerve identification correctness were determined. Results: The analysis included 61 studies on pelvic nerve anatomy. A main positional reference was defined for each nerve. On MRI, the sacral nerves, the lumbosacral plexus, and the obturator nerve could be identified bilaterally in all volunteers. The sympathetic trunk could be identified in 19 of 20 volunteers bilaterally (95%). The superior hypogastric plexus, the hypogastric nerve, and the inferior hypogastric plexus could be identified bilaterally in 14 (70%), 16 (80%), and 14 (70%) of the 20 volunteers, respectively. The pudendal nerve could be identified in 17 (85%) volunteers on the right side and in 13 (65%) volunteers on the left side. The levator ani nerve could be identified in only a few volunteers. Except for the levator ani nerve, the radiologist and the anatomist agreed that the delineated nerve depicted the correct nerve in 100% of the cases. Conclusion: Pelvic nerves at risk of injury are usually visible on high-resolution MRI w