GABA Maintains the Proliferation of Progenitors in the Developing Chick Ciliary Marginal Zone and Non-Pigmented Ciliary Epithelium

GABA is more than the main inhibitory neurotransmitter found in the adult CNS. Several studies have shown that GABA regulates the proliferation of progenitor and stem cells. This work examined the effects of the GABAA receptor system on the proliferation of retinal progenitors and non-pigmented ciliary epithelial (NPE) cells. qRT-PCR and whole-cell patch-clamp electrophysiology were used to characterize the GABAA receptor system. To quantify the effects on proliferation by GABAA receptor agonists and antagonists, incorporation of thymidine analogues was used. The results showed that the NPE cells express functional extrasynaptic GABAA receptors with tonic properties and that low concentration of GABA is required for a baseline level of proliferation. Antagonists of the GABAA receptors decreased the proliferation of dissociated E12 NPE cells. Bicuculline also had effects on progenitor cell proliferation in intact E8 and E12 developing retina. The NPE cells had low levels of the Cl–transporter KCC2 compared to the mature retina, suggesting a depolarising role for the GABAA receptors. Treatment with KCl, which is known to depolarise membranes, prevented some of the decreased proliferation caused by inhibition of the GABAA receptors. This supported the depolarising role for the GABAA receptors. Inhibition of L-type voltage-gated Ca2+ channels (VGCCs) reduced the proliferation in the same way as inhibition of the GABAA receptors. Inhibition of the channels increased the expression of the cyclin-dependent kinase inhibitor p27KIP1, along with the reduced proliferation. These results are consistent with that when the membrane potential indirectly regulates cell proliferation with hyperpolarisation of the membrane potential resulting in decreased cell division. The increased expression of p27KIP1 after inhibition of either the GABAA receptors or the L-type VGCCs suggests a link between the GABAA receptors, membrane potential, and intracellular Ca2+ in regulating the cell cycle

The PREDICTS database: A global database of how local terrestrial biodiversity responds to human impacts

© 2014 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015. The collation of biodiversity datasets with broad taxonomic and biogeographic extents is necessary to understand historical declines and to project - and hopefully avert - future declines. We describe a newly collated database of more than 1.6 million biodiversity measurements from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world

Global Diversity of Ascidiacea

The class Ascidiacea presents fundamental opportunities for research in the fields of development, evolution, ecology, natural products and more. This review provides a comprehensive overview of the current knowledge regarding the global biodiversity of the class Ascidiacea, focusing in their taxonomy, main regions of biodiversity, and distribution patterns. Based on analysis of the literature and the species registered in the online World Register of Marine Species, we assembled a list of 2815 described species. The highest number of species and families is found in the order Aplousobranchia. Didemnidae and Styelidae families have the highest number of species with more than 500 within each group. Sixty percent of described species are colonial. Species richness is highest in tropical regions, where colonial species predominate. In higher latitudes solitary species gradually contribute more to the total species richness. We emphasize the strong association between species richness and sampling efforts, and discuss the risks of invasive species. Our inventory is certainly incomplete as the ascidian fauna in many areas around the world is relatively poorly known, and many new species continue to be discovered and described each year

Increase in spleen volume as a predictor of oxaliplatin toxicity

Alissar El Chediak,1 Ali A Haydar,2 Ayman Hakim,1 Sarah Abdel Massih,1 Lara Hilal,3 Deborah Mukherji,1 Sally Temraz,1 Ali Shamseddine1 1Department of Internal Medicine, Division of Hematology-Oncology, American University of Beirut-Medical Center, Beirut, Lebanon; 2Department of Diagnostic Radiology, American University of Beirut-Medical Center, Beirut, Lebanon; 3Department of Radiation Oncology, American University of Beirut-Medical Center, Beirut, Lebanon Background: Oxaliplatin is a nonconventional third-generation platinum compound. It is an important chemotherapeutic agent in regimens used in gastrointestinal carcinomas as well as other malignancies. Oxaliplatin toxicity profile includes neurotoxicity, hepatotoxicity, and splenomegaly. The primary aim of this study was to measure the spleen volume of patients on oxaliplatin therapy before and during chemotherapy to detect any increase in splenic size as a biomarker for early oxaliplatin toxicity. Methods: This was a prospective pilot study conducted at the American University of Beirut-Medical Center. Fifty patients newly started on oxaliplatin were included. The spleen volume was measured from the patients’ baseline CT scan using the IntelliSpace Portal upgraded system (using Response Evaluation Criteria In Solid Tumors [RECIST]), for each follow-up CT scan. Side effects were evaluated at each patient visit and graded according to the severity. Results: Thirty-seven (74%) patients developed an increase in spleen size. Thirty-three (66%) sampled patients developed peripheral neuropathy (all grades) at 3 months, whereas only two (4%) patients developed grade 3 neuropathy. Only one (3%) patient who developed an increase in spleen size also developed grade 3 peripheral neuropathy – a result that is significantly different (p<0.001) when comparing patients with an increase in spleen size who also developed peripheral neuropathy of other grades.Conclusion: An increase in spleen volume possibly precedes a significant peripheral neuropathy which could be a potential marker for oxaliplatin-induced toxicity.Keywords: oxaliplatin, toxicity, neuropathy, splenomegaly, neuropathy, hepatic sinusoidal injur