Alternative male morphs solve sperm performance/longevity trade-off in opposite directions

Males pursuing alternative reproductive tactics have been predicted to face a trade-off between maximizing either swimming performance or endurance of their sperm. However, empirical evidence for this trade-off is equivocal, which may be due to simplistic assumptions. In the shell-brooding cichlid fish Lamprologus callipterus, two Mendelian male morphs compete for fertilization by divergent means: Bourgeois nest males ejaculate sperm, on average, about six times farther from the unfertilized ova than do parasitic dwarf males. This asymmetry is opposite to the usual situation, in which bourgeois males typically benefit from superior fertilization opportunities, suggesting that nest males' sperm should persist longer than dwarf male sperm. The assumed trade-off between sperm swimming performance and longevity predicts that, in turn, sperm of dwarf males should outperform that of nest males in swimming efficiency. Measurement of sperm performance and endurance reveals that dwarf male spermatozoa swim straighter initially than those of nest males, but their motility declines earlier and their velocity slows down more abruptly. Nest male sperm survives longer, which relates to a larger sperm head plus midpiece, implying more mitochondria. Thus, the trade-off between sperm performance and endurance is optimized in opposite directions by alternative male morphs. We argue that the relative success of alternative sperm performance strategies can be influenced strongly by environmental factors such as the time window between gamete release and fertilization, and the position of gamete release. This is an important yet little understood aspect of gametic adaptations to sperm competition

Emerging therapeutic options for breast cancer chemotherapy during pregnancy

Rak piersi jest najczęstszym guzem litym obserwowanym u kobiet w ciąży. Antracyklina jest jednym z leków, które można stosować w chemioterapii ciężarnych w drugim i trzecim trymestrze ciąży. Istnieje niestety mało danych dotyczących możliwości stosowania w terapii w tym okresie ciąży nowych i bardzo skutecznych leków, takich jak taksany, winorelbina czy czynniki anty-HER-2. W celu oceny profilu bezpieczeństwa stosowania tych leków u ciężarnych pacjentek przeprowadzono wszechstronny przegląd dokumentacji dostępnej w piśmiennictwie anglojęzycznym na temat użycia taksanów, winorelbiny, trastuzumabu oraz lapatinibu podczas ciąży. Opisano 24 przypadki ciąż, w których nie zaobserwowano efektów toksycznych 3–4 stopnia u matki ani malformacji u płodu. Mimo iż tylko w jednej z tych prac oceniano farmakokinetykę paklitakselu (Taxol) podczas ciąży, liczne przeprowadzone badania przedkliniczne wskazują, że łożyskowa P-glikoproteina może zapobiegać przezłożyskowemu transferowi taksanów i winorelbiny. Stosowanie trastuzumabu w 3 z 6 przypadków wiązało się z występowaniem bezwodzia. W czasie drugiego i trzeciego trymestru ciąży istnieje możliwość stosowania nowych leków charakteryzujących się korzystnym profilem toksyczności, takich jak taksany i winorelbina, natomiast czynniki anty- HER-2 mogą zaburzać prawidłowy rozwój nerek u płodu i nie powinno się ich stosować u kobiet w ciąży.Breast cancer is the commonest solid tumor observed during pregnancy. Anthracycline-based chemotherapy is feasible during the 2nd and 3rd trimesters of pregnancy, but few data are available on recent and highly active drugs taxanes, vinorelbine and anti-HER-2 agents in this setting. We carried out a comprehensive review of reports documenting the use of taxanes, vinorelbine, trastuzumab and lapatinib during pregnancy in the English literature, in order to evaluate their safety profile in pregnant patients. Twenty-four pregnancies are described, in which no grade 3–4 maternal toxicity nor malformation in the offspring was reported. Whereas only one report studied the pharmacokinetics of paclitaxel (Taxol) during pregnancy, several preclinical reports indicate that the placental P-glycoprotein could prevent the transplacental transfer of taxanes and vinorelbine. The use of trastuzumab was associated with the occurrence of anhydramnios in three of six cases. The administration of recent drugs taxanes and vinorelbine seems feasible during the 2nd and 3rd trimesters of pregnancy, with a favorable toxicity profile. In contrast, anti-HER-2 agents may obscure the normal development of the fetal kidney, and should be avoided during pregnancy

Macroclimatic structuring of spatial phylogenetic turnover in liverworts

Phylogenetic turnover has emerged as a powerful tool to identify the mechanisms by which biological communities assemble. When significantly structured along environmental gradients, phylogenetic turnover evidences phylogenetic niche conservatism, a critical principle explaining patterns of species distributions at different spatio-temporal scales. Here, we quantify the contribution of geographic or macroclimatic drivers to explain patterns of phylogenetic turnover in an entire phylum of land plants, namely liverworts. We further determine whether climatic niche conservatism has constrained the distribution of liverworts in the course of their evolutionary history. Two datasets, one insular, focused on 60 archipelagos and including 2346 species, and the second global, including 6334 species in 451 oceanic and continental Operational Geographic Units (OGUs) worldwide, were assembled. Phylogenetic turnover among OGUs was quantified through πst statistics. πst-throughtime profiles were generated at 1 myr intervals along the phylogenetic time-scale and used to compute the correlation between πst, current geographic distance and macroclimatic variation with Mantel tests based on Moran spectral randomization to control for spatial autocorrelation. The contribution of macroclimatic variation to phylogenetic turnover was about four-times higher than that of geographic distance, a pattern that was consistently observed in island and global geographic settings, and with datasets including or excluding species-poor OGUs. The correlation between phylogenetic turnover and geographic distance rapidly decayed at increasing phylogenetic depth, whereas the relationship with macroclimatic variation remained constant until 100 mya. Our analyses reveal that changes in the phylogenetic composition among liverwort floras across the globe are primarily shaped by macroclimatic variation. They demonstrate the relevance of macroclimatic niche conservatism for the assembly of liverwort floras over very large spatial and evolutionary time scales, which may explain why such a pervasive biodiversity pattern as the increase of species richness towards the tropics also applies to organisms with high dispersal capacities

Prevalence and mechanisms of resistance to carbapenems in Enterobacteriaceae

Objectives: To determine the point prevalence of carbapenem-non-susceptible Enterobacteriaceae (CNSE) and carbapenemase-producing Enterobacteriaceae (CPE) isolates among hospitalized patients in Belgium. Methods: Twenty-four hospital-based laboratories prospectively collected 200 non-duplicated Enterobacteriaceae isolates from clinical specimens of hospitalized patients over a 2 month period. All isolates were screened locally for decreased susceptibility to carbapenem drugs using a disc diffusion method according to CLSI interpretative criteria. CNSE strains were referred centrally for confirmation of carbapenemase by phenotypic and molecular testing. Results: From February to April 2012, 158 of the 4564 screened Enterobacteriaceae isolates were categorized as non-susceptible to carbapenems, resulting in a point prevalence of CNSE of 3.5% (95% CI: 2.9%–4.2%; range per centre: 0.5%–8.5%). Of the 125 referred CNSE isolates, 11 Klebsiella pneumoniae isolates [OXA-48 (n=7), KPC type (n=3) and NDM type (n=1)], 1 OXA-48-positive Escherichia coli isolate and 1 KPC-positive Klebsiella oxytoca isolate were detected in eight hospitals. None of the 72 carbapenem-non-susceptible Enterobacter spp. isolates were confirmed as CPE. The minimal estimated point prevalence of CPE isolates was 0.28% (13/ 4564; 95% CI: 0.13%–0.44%) overall (range per centre: 0%–1.5%). Conclusions: Despite the overall low prevalence of CNSE found in this study, the detection of CPE isolates in one-third of the participating centres raises concerns and highly suggests the spread and establishment of CPE in Belgian hospitals

Tetherin Restricts Productive HIV-1 Cell-to-Cell Transmission

The IFN-inducible antiviral protein tetherin (or BST-2/CD317/HM1.24) impairs release of mature HIV-1 particles from infected cells. HIV-1 Vpu antagonizes the effect of tetherin. The fate of virions trapped at the cell surface remains poorly understood. Here, we asked whether tetherin impairs HIV cell-to-cell transmission, a major means of viral spread. Tetherin-positive or -negative cells, infected with wild-type or ΔVpu HIV, were used as donor cells and cocultivated with target lymphocytes. We show that tetherin inhibits productive cell-to-cell transmission of ΔVpu to targets and impairs that of WT HIV. Tetherin accumulates with Gag at the contact zone between infected and target cells, but does not prevent the formation of virological synapses. In the presence of tetherin, viruses are then mostly transferred to targets as abnormally large patches. These viral aggregates do not efficiently promote infection after transfer, because they accumulate at the surface of target cells and are impaired in their fusion capacities. Tetherin, by imprinting virions in donor cells, is the first example of a surface restriction factor limiting viral cell-to-cell spread

Alcohol consumption and head and neck cancer

peer reviewe

Comparison between the Natural Postnatal Maturation and the Spermine-Induced Maturation of the Rat Intestine

peer reviewedIn the suckling rats, orally provided spermine induced structural and biochemical changes in the intestine, which are characteristics of the postnatal maturation. This induced maturation was compared to that occurring spontaneously. Eight mumol spermine were administered orally once a day, for one or three days, to suckling rats which were 11 days old at the beginning of the experiment. The animals were killed 0, 2, 4, 6, 8, 10 hours or 3 days after the first treatment. Control rats from the same litter were treated in the same way but received only the vehicle. In order to complete the study of the naturally occurring maturation, another group of rats was killed when they were 12, 13, 15, 16, 17, 18, 19, 20, 21 or 30 days old. Animal and intestine weights were measured. Disaccharidase specific activity, and protein, DNA and RNA contents were estimated in the small intestine. Histological and ultrastructural aspects of the intestinal mucosa were examined. For all these parameters, the maturation induced by spermine ingestion appeared close to that occurring naturally at weaning. Consequently, dietary spermine induces all the morphological and biochemical modifications characterizing the intestinal postnatal maturation in the suckling rat suggesting a role of the polyamines in the naturally occurring processes

Reproductive investment of giants and dwarfs: specialized tactics in a cichlid fish with alternative male morphs

1. Adopting alternative reproductive tactics may require divergent solutions to reproductive competition among individuals of a population. Often investment in reproduction differs sub-stantially between individuals pursuing bourgeois and parasitic tactics, which may result in dif-ferent trade-offs and limitations. 2. Here we identify divergent behavioural, morphological and physiological traits of bourgeois and parasitic male morphs in Lamprologus callipterus, a Lake Tanganyika cichlid with an extreme size dimorphism among males. We focus on limiting factors and compare these between large, nest-building males and dwarf males parasitizing their reproductive effort. 3. Only nest males invest in courtship, and they exhibit much more aggression than dwarf males. In contrast, dwarf males spend 20 % of their time feeding, whereas nest males hardly ever feed. 4. Nest males accumulate reserves before breeding and use these up before taking a reproductive break, thereby performing a ‘capital breeder ’ strategy. In contrast, dwarf males use assimilated energy immediately for reproduction, thus acting as ‘income breeders’. This is a requirement of their spawning tactic, which only works out with a small and slim body. 5. A field experiment showed that nest males lose weight by their restricted feeding opportunitie

Quality indicators for continuous monitoring to improve maternal and infant health in maternity departments: a modified Delphi survey of an international multidisciplinary panel.

OBJECTIVE: Measuring the quality of inpatient obstetrical care using quality indicators is becoming increasingly important for both patients and healthcare providers. However, there is no consensus about which measures are optimal. We describe a modified Delphi method to identify a set of indicators for continuously monitoring the quality of maternity care by healthcare professionals. METHODOLOGY AND MAIN FINDINGS: An international French-speaking multidisciplinary panel comprising 22 obstetricians-gynaecologists, 12 midwives, and 1 paediatrician assessed potential indicators extracted from a medical literature search, using a two-round Delphi procedure followed by a physical meeting. Each panellist rated each indicator based on validity and feasibility. In the first round, 35 panellists from 5 countries and 20 maternity units evaluated 26 indicators including 15 related to the management of the overall population of pregnant women, 3 to the management of women followed from the first trimester of pregnancy, 2 to the management of low-risk pregnant women, and 6 to the management of neonates. 25 quality indicators were kept for next step. In the second round, 27 (27/35: 77%) panellists selected 17 indicators; the remaining 8 indicators were discussed during a physical meeting. The final set comprised 18 indicators. CONCLUSION: A multidisciplinary panel selected indicators that reflect the quality of obstetrical care. This set of indicators could be used to assess and monitor obstetrical care, with the goal of improving the quality of care in maternity units