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Selected AbstractsFrom genomes to morphology: a view from amphioxusACTA ZOOLOGICA, Issue 1 2010Peter W. H. Holland Abstract Holland, P.W.H. 2010. From genomes to morphology: a view from amphioxus. ,Acta Zoologica (Stockholm) 91: 81,86 As complete genome sequences are determined from an ever-increasing number of animal species, new opportunities are arising for comparative biology. For zoologists interested in the evolution of shape and form, however, there is a problem. The link between genome sequence and morphology is not direct and is obfuscated by complex and evolving genetic pathways, even when conserved regulatory genes are considered. Nonetheless, a large-scale comparison of genome sequences between extant chordates reveals an intriguing parallel between genotypic and phenotypic evolution. Tunicates have highly altered genomes, with loss of ancestral genes and shuffled genetic arrangements, while vertebrate genomes are also derived through gene loss and genome duplication. The recently sequenced amphioxus genome, in contrast, reveals much greater stasis on the cephalochordate lineage, in parallel to a less derived body plan. The opportunities and challenges for relating genome evolution to morphological evolution are discussed. [source] Rationale and Design of ATHENA: A Placebo-Controlled, Double-Blind, Parallel Arm Trial to Assess the Efficacy of Dronedarone 400 mg Bid for the Prevention of Cardiovascular Hospitalization or Death from Any Cause in PatiENts with Atrial Fibrillation/Atrial FlutterJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2008STEFAN H. HOHNLOSER M.D. Background: Atrial fibrillation (AF) is the most commonly encountered clinical arrhythmia, predominantly affecting elderly patients. There is a continued need for new antiarrhythmic drugs to treat the ever-increasing number of patients with this arrhythmia. Dronedarone is a new antiarrhythmic compound currently being developed for treatment of AF. Methods: The ATHENA trial (A placebo-controlled, double-blind, parallel arm Trial to assess the efficacy of dronedarone 400 mg bid for the prevention of cardiovascular Hospitalization or death from any cause in patiENts with Atrial fibrillation/atrial flutter) is the largest single antiarrhythmic drug trial ever conducted. More than 4,600 patients with a history of AF or atrial flutter (AFL) have been randomized to receive dronedarone 400 mg bid or matching placebo. The primary study endpoint is time to first cardiovascular hospitalization or death from any cause. The study has completed patient enrollment in December 2006 and is expected to end follow-up 1 year later. Conclusion: ATHENA will be the largest efficacy and safety trial of dronedarone, a multichannel blocker compound with properties from class I, II, III, and IV antiarrhythmic drugs developed to treat patients with AF. [source] Genetic structure and gene flow in French populations of two Ostrinia taxa: host races or sibling species?MOLECULAR ECOLOGY, Issue 20 2007T. MALAUSA Abstract Most models of ecological speciation concern phytophagous insects in which speciation is thought to be driven by host shifts and subsequent adaptations of populations. Despite the ever-increasing number of studies, the current evolutionary status of most models remains incompletely resolved, as estimates of gene flow between taxa remain extremely rare. We studied the population genetics of two taxa of the Ostrinia genus , one feeding mainly on maize and the other on mugwort and hop , occurring in sympatry throughout France. The actual level of divergence of these taxa was unknown because the genetic structure of populations had been investigated over a limited geographical area and the magnitude of gene flow between populations had not been estimated. We used 11 microsatellite markers to investigate the genetic structure of populations throughout France and the extent of gene flow between the two Ostrinia taxa at several sites at which they are sympatric. We observed clear genetic differentiation between most populations collected on the typical respective hosts of each taxon. However, populations displaying intermediate allelic frequencies were found on hop plants in southern France. Individual assignments revealed that this result could be accounted for by the presence of both taxa on the same host. Gene flow, estimated by determining the proportion of hybrids detected, was low: probably < 1% per generation, regardless of site. This indicates that the two Ostrinia taxa have reached a high level of genetic divergence and should be considered sibling species rather than host races. [source] A physiological overview of the genetics of flowering time controlPLANT BIOTECHNOLOGY JOURNAL, Issue 1 2005Georges Bernier Summary Physiological studies on flowering time control have shown that plants integrate several environmental signals. Predictable factors, such as day length and vernalization, are regarded as ,primary', but clearly interfere with, or can even be substituted by, less predictable factors. All plant parts participate in the sensing of these interacting factors. In the case of floral induction by photoperiod, long-distance signalling is known to occur between the leaves and the shoot apical meristem (SAM) via the phloem. In the long-day plant, Sinapis alba, this long-distance signalling has also been shown to involve the root system and to include sucrose, nitrate, glutamine and cytokinins, but not gibberellins. In Arabidopsis thaliana, a number of genetic pathways controlling flowering time have been identified. Models now extend beyond ,primary' controlling factors and show an ever-increasing number of cross-talks between pathways triggered or influenced by various environmental factors and hormones (mainly gibberellins). Most of the genes involved are preferentially expressed in meristems (the SAM and the root tip), but, surprisingly, only a few are expressed preferentially or exclusively in leaves. However, long-distance signalling from leaves to SAM has been shown to occur in Arabidopsis during the induction of flowering by long days. In this review, we propose a model integrating physiological data and genes activated by the photoperiodic pathway controlling flowering time in early-flowering accessions of Arabidopsis. This model involves metabolites, hormones and gene products interacting as long- or short-distance signalling molecules. [source] eDrug: a dynamic interactive electronic drug formulary for medical studentsBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 6 2006Simon R. J. Maxwell What is already known about this subject ,,Delivering education about an ever-increasing number of prescribable drugs to medical students represents a major challenge. ,,Drug names are generally not logical or intuitive, and many students find learning them akin to learning a foreign language. ,,Pharmacology and therapeutics teaching is struggling for visibility in some integrated medical curricula. What this study adds ,,Development of electronic tools allowing web delivery of a restricted student formulary facilitates dynamic access to core learning materials, improves the profile of this aspect of the curriculum and is highly appreciated by students. Aims Prescribing drugs is a key responsibility of a doctor and requires a solid grounding in the relevant scientific disciplines of pharmacology and therapeutics (PT). The move away from basic science disciplines towards a more system-based and integrated undergraduate curriculum has created difficulties in the delivery of PT teaching in some medical schools. We aimed to develop a web-based strategy to overcome these problems and improve the PT learning experience. Methods We designed and introduced ,eDrug', a dynamic interactive web-based student formulary, as an aid to teaching and learning of PT throughout a 5-year integrated medical curriculum in a UK medical school of 1300 students. This was followed by a prospective observational study of student-reported views about its impact on their PT learning experience. Results eDrug was rated highly by students and staff, with the main benefits being increased visibility of PT in the curriculum, clear identification of core drugs, regular sourcing of drug information via direct links to accredited sources including the British National Formulary, prioritization of learning, immediate access and responsiveness. It has also served as a focus of discussion concerning core PT learning objectives amongst staff and students. Conclusions Web-based delivery of PT learning objectives actively supports learning within an integrated curriculum. [source] Non-conventional use of growth hormone therapyACTA PAEDIATRICA, Issue 2006Marco Cappa Abstract Human growth hormone therapy is allowed in certain clinical conditions according to national healthcare criteria. Growth hormone, however, produces a wide spectrum of effects. Linear growth is only one of the many expected results, and there are interesting possibilities to explore which could provide additional means of improving the quality of life for the ever-increasing numbers of chronic paediatric patients. Conclusion: In this review, we discuss the rationale for and possibility of using growth hormone therapy in some conditions not strictly related to growth hormone deficiency. [source] | |||||||||||||