A single mutation results in diploid gamete formation and parthenogenesis in a Drosophila yemanuclein-alpha meiosis I defective mutant

<p>Abstract</p> <p>Background</p> <p>Sexual reproduction relies on two key events: formation of cells with a haploid genome (the gametes) and restoration of diploidy after fertilization. Therefore the underlying mechanisms must have been evolutionary linked and there is a need for evidence that could support such a model.</p> <p>Results</p> <p>We describe the identification and the characterization of <it>yem¹</it>, the first <it>yem-alpha </it>mutant allele (V478E), which to some extent affects diploidy reduction and its restoration. Yem-alpha is a member of the Ubinuclein/HPC2 family of proteins that have recently been implicated in playing roles in chromatin remodeling in concert with HIRA histone chaperone. The <it>yem¹</it>mutant females exhibited disrupted chromosome behavior in the first meiotic division and produced very low numbers of viable progeny. Unexpectedly these progeny did not display paternal chromosome markers, suggesting that they developed from diploid gametes that underwent gynogenesis, a form of parthenogenesis that requires fertilization.</p> <p>Conclusions</p> <p>We focus here on the analysis of the meiotic defects exhibited by <it>yem¹</it>oocytes that could account for the formation of diploid gametes. Our results suggest that <it>yem¹</it>affects chromosome segregation presumably by affecting kinetochores function in the first meiotic division.</p> <p>This work paves the way to further investigations on the evolution of the mechanisms that support sexual reproduction.</p

On the study of catalytic membrane reactor for water detritiation: Membrane characterization.

Tritium waste recycling is a real economic and ecological issue. Generally under the non-valuable Q2Oform (Q = H, D or T), waste can be converted into fuel Q2for a fusion machine (e.g. JET, ITER) by isotopeexchange reaction Q2O + H2= H2O + Q2. Such a reaction is carried out over Ni-based catalyst bed packed ina thin wall hydrogen permselective membrane tube. This catalytic membrane reactor can achieve higherconversion ratios than conventional fixed bed reactors by selective removal of reaction product Q2bythe membrane according to Le Chatelier’s Law. This paper presents some preliminary permeation tests performed on a catalytic membrane reactor.Permeabilities of pure hydrogen and deuterium as well as those of binary mixtures of hydrogen, deu-terium and nitrogen have been estimated by measuring permeation fluxes at temperatures ranging from573 to 673 K, and pressure differences up to 1.5 bar. Pure component global fluxes were linked to perme-ation coefficient by means of Sieverts’ law. The thin membrane (150 �m), made of Pd–Ag alloy (23 wt.%Ag),showed good permeability and infinite selectivity toward protium and deuterium. Lower permeabilityvalues were obtained with mixtures containing non permeable gases highlighting the existence of gasphase resistance. The sensitivity of this concentration polarization phenomenon to the composition andthe flow rate of the inlet was evaluated and fitted by a two-dimensional model

Therapeutic activity of two xanthones in a xenograft murine model of human chronic lymphocytic leukemia

<p>Abstract</p> <p>Background</p> <p>We previously reported that allanxanthone C and macluraxanthone, two xanthones purified from <it>Guttiferae </it>trees, display <it>in vitro </it>antiproliferative and proapoptotic activities in leukemic cells from chronic lymphocytic leukemia (CLL) and leukemia B cell lines.</p> <p>Results</p> <p>Here, we investigated the <it>in vivo </it>therapeutic effects of the two xanthones in a xenograft murine model of human CLL, developed by engrafting CD5-transfected chronic leukemia B cells into SCID mice. Treatment of the animals with five daily injections of either allanxanthone C or macluraxanthone resulted in a significant prolongation of their survival as compared to control animals injected with the solvent alone (<it>p </it>= 0.0006 and <it>p </it>= 0.0141, respectively). The same treatment of mice which were not xenografted induced no mortality.</p> <p>Conclusion</p> <p>These data show for the first time the <it>in vivo </it>antileukemic activities of two plant-derived xanthones, and confirm their potential interest for CLL therapy.</p

Safety and feasibility of a Dalcroze eurhythmics and a simple home exercise program among older adults with mild cognitive impairment (MCI) or mild dementia: the MOVE for your MIND pilot trial

Background Falls represent a major health problem for older adults with cognitive impairment, and the effects of exercise for fall reduction are understudied in this population. This pilot randomized controlled trial evaluated the feasibility, safety, and exploratory effectiveness of a Dalcroze eurhythmics program and a home exercise program designed for fall prevention in older adults with mild cognitive impairment (MCI) or early dementia. Methods For this three-arm, single-blind, 12-month randomized controlled pilot trial, we recruited community-dwelling women and men age 65 years and older with MCI or early dementia through participating memory clinics in Zurich, Switzerland. Participants were randomly assigned to a Dalcroze eurhythmics group program, a simple home exercise program (SHEP), or a non-exercise control group. All participants received 800 IU of vitamin D3 per day. The main objective of the study was to test the feasibility of recruitment and safety of the interventions. Additional outcomes included fall rate, gait performance, and cognitive function. Results Over 12 months, 221 older adults were contacted and 159 (72%) were screened via telephone. Following screening, 12% (19/159) met the inclusion criteria and were willing to participate. One participant withdrew at the end of the baseline visit and 18 were randomized to Dalcroze eurhythmics (n = 7), SHEP (n = 5), or control (n = 6). Adherence was similarly low in the Dalcroze eurhythmics group (56%) and in the SHEP group (62%; p = 0.82). Regarding safety and pilot clinical endpoints, there were no differences between groups. Conclusion The MOVE for your MIND pilot study showed that recruitment of older adults with MCI or early dementia for long-term exercise interventions is challenging. While there were no safety concerns, adherence to both exercise programs was low

SCORODOPHLONE A, A NOVEL ALKYLSULFONE FROM THE SEEDS OF SCORODOPHLOEUS ZENKERI. HARMS

A novel alkylsulfone, scorodophlone A 1, from the seeds of Scorodophloeus zenkeri Harms, has been assigned the structure 6-(methylsulfonyl)-1,2,3-dithiazinan-4-one on the basis of its spectroscopic properties. The known compounds &alpha;-sophoradiol (12-oleanene-3&beta;,22&alpha;-diol), lupeol and sitosterol were also obtained. KEY WORDS: Scorodophloeus zenkeri, Caesalpiniaceae, Scorodophlone A, Pentacyclic triterpene, Phytosterol Bull. Chem. Soc. Ethiop. 2006, 20(1), 173-176

The major element of 1-year prognosis in acute coronary syndromes is severity of initial clinical presentation: Results from the French MONICA registries

SummaryBackgroundWhile the death rate from acute coronary syndromes (ACS) has been in decline for more than 50years, out-of-hospital mortality remains high despite improvements in care.AimTo evaluate the importance of out-of-hospital mortality and identify the main predictors of in-hospital and 1-year mortality in France.MethodsAnalyses were based on data from the French MONICA population-based registry, which included all cases of ACS occurring in people aged 35–74years during 2006 in three geographic areas in France. We first evaluated out-of-hospital mortality; then, using data from patients with incident ACS who reached hospital alive, Cox models were performed to determine the main predictors of 1-year mortality. The number of attributable deaths was assessed for variables of interest.ResultsAfter 1-year follow-up, case-fatality was 29.3% for incident events (n=2547); the proportion of out-of-hospital deaths was 70.3%, and 91.5% of deaths occurred in the 28days following the ACS. On multivariable analysis, the number of attributable deaths associated with three scenarios (out-of-hospital life-and-death emergency, hospitalization before ACS occurrence, and lack of coronary angiography) was 130 (accounting for 59% of deaths occurring after reaching the hospital) during 1-year follow-up. These scenarios corresponded to patients with an initial severe clinical presentation in whom rates of use of specific treatments and invasive procedures were very low.ConclusionA large proportion of fatalities after an ACS occurs in the out-of-hospital phase. Moreover, the major component of 1-year mortality is associated with a poor prognosis at initial presentation. This finding highlights the importance of cardiovascular prevention, population education and better out-of-hospital emergency management in improving prognosis after an ACS

Prevalence of Physical Activity and Sedentary Behavior Patterns in Generally Healthy European Adults Aged 70 Years and Older—Baseline Results From the DO-HEALTH Clinical Trial

Background: Physical activity (PA) is important for healthy aging and disease prevention whereas sedentary behavior (SB) accelerates health deterioration. Aim: To investigate activity profiles regarding PA and SB among generally healthy European older adults. Methods: Meeting PA recommendations was defined as ≥150 min/week of moderate and/or ≥75 min/week of vigorous PA. A cut-off of ≥5.5 h/day was used to define time spent with SB. We present prevalence of PA and SB overall and by sex, age, BMI, and country. We examined correlates with multivariate logistic regression models. Results: Two thousand one hundred and fifty-five DO-HEALTH participants completed baseline information on activity profiles [mean age 74.9 years (SD 4.5), 61.8% women]. Overall, 62.2% met PA recommendations and overall, 37.1% spent ≥5.5 h/day with SB. Younger participants (70–74 years), men, and those with BMI <25 kg/m2 met PA recommendations more often. Per country, prevalence of meeting PA recommendations were: Austria 74.4%, France 51.0%, Germany 65.6%, Portugal 46.5%, and Switzerland 66.7%. Regarding SB, prevalence did not differ in all subgroups. In multivariate logistic regression analyses, being male, younger age, lower MoCA scores, and higher SPPB score were associated with greater odds, whereas higher BMI, more years of education, higher GDS score, and residing in Portugal were associated with lower odds of meeting PA recommendations. High BMI and higher MoCA scores were associated with greater odds of high SB. Conclusion: Individualized public health efforts may be warranted even in active older adults, as profiles were less favorable in subgroups of older age, female sex and higher BM

On the study of catalytic membrane reactor for water detritiation: Modeling approach

In the framework of tritium recovery from tritiated water, efficiency of packed bed membrane reactors have been successfully demonstrated. Thanks to protium isotope swamping, tritium bonded water can be recovered under the valuable Q2 form (Q = H, D or T) by means of isotope exchange reactions occurring on catalyst surface. The use of permselective Pd-based membrane allows withdrawal of reactions products all along the reactor, and thus limits reverse reaction rate to the benefit of the direct one (shift effect). The reactions kinetics, which are still little known or unknown, are generally assumed to be largely greater than the permeation ones so that thermodynamic equilibriums of isotope exchange reactions are generally assumed. This paper proposes a new phenomenological 2D model to represent catalytic membrane reactor behavior with the determination of gas effluents compositions. A good agreement was obtained between the simulation results and experimental measurements performed on a dedicated facility. Furthermore, the gas composition estimation permits to interpret unexpected behavior of the catalytic membrane reactor. In the next future, further sensitivity analysis will be performed to determine the limits of the model and a kinetics study will be conducted to assess the thermodynamic equilibrium of reaction

Rabies virus matrix protein interplay with eIF3, new insights into rabies virus pathogenesis

Viral proteins are frequently multifunctional to accommodate the high density of information encoded in viral genomes. Matrix (M) protein of negative-stranded RNA viruses such as Rhabdoviridae is one such example. Its primary function is virus assembly/budding but it is also involved in the switch from viral transcription to replication and the concomitant down regulation of host gene expression. In this study we undertook a search for potential rabies virus (RV) M protein's cellular partners. In a yeast two-hybrid screen the eIF3h subunit was identified as an M-interacting cellular factor, and the interaction was validated by co-immunoprecipitation and surface plasmon resonance assays. Upon expression in mammalian cell cultures, RV M protein was localized in early small ribosomal subunit fractions. Further, M protein added in trans inhibited in vitro translation on mRNA encompassing classical (Kozak-like) 5′-UTRs. Interestingly, translation of hepatitis C virus IRES-containing mRNA, which recruits eIF3 via a different noncanonical mechanism, was unaffected. Together, the data suggest that, as a complement to its functions in virus assembly/budding and regulation of viral transcription, RV M protein plays a role in inhibiting translation in virus-infected cells through a protein–protein interaction with the cellular translation machinery

Biocompatibility and Bone Formation of Flexible, Cotton Wool-like PLGA/Calcium Phosphate Nanocomposites in Sheep

BACKGROUND: The purpose of this preliminary study was to assess the in vivo performance of synthetic, cotton wool-like nanocomposites consisting of a biodegradable poly(lactide-co-glycolide) fibrous matrix and containing either calcium phosphate nanoparticles (PLGA/CaP 60:40) or silver doped CaP nanoparticles (PLGA/Ag-CaP 60:40). Besides its extraordinary in vitro bioactivity the latter biomaterial (0.4 wt% total silver concentration) provides additional antimicrobial properties for treating bone defects exposed to microorganisms. MATERIALS AND METHODS: Both flexible artificial bone substitutes were implanted into totally 16 epiphyseal and metaphyseal drill hole defects of long bone in sheep and followed for 8 weeks. Histological and histomorphological analyses were conducted to evaluate the biocompatibility and bone formation applying a score system. The influence of silver on the in vivo performance was further investigated. RESULTS: Semi-quantitative evaluation of histology sections showed for both implant materials an excellent biocompatibility and bone healing with no resorption in the adjacent bone. No signs of inflammation were detectable, either macroscopically or microscopically, as was evident in 5 µm plastic sections by the minimal amount of inflammatory cells. The fibrous biomaterials enabled bone formation directly in the centre of the former defect. The area fraction of new bone formation as determined histomorphometrically after 8 weeks implantation was very similar with 20.5 ± 11.2 % and 22.5 ± 9.2 % for PLGA/CaP and PLGA/Ag-CaP, respectively. CONCLUSIONS: The cotton wool-like bone substitute material is easily applicable, biocompatible and might be beneficial in minimal invasive surgery for treating bone defects