Modulatory effect of methanolic extract of Vernonia amygdalina (MEVA) on tert‐butyl hydroperoxide–induced erythrocyte haemolysis

Reactive oxygen species (ROS) have been implicated in the aetiology of several pathological and degenerative diseases. The protective effect of natural products possessing antioxidant properties has played a crucial role in ameliorating these deleterious effects. This study investigated the chemoprotective properties of the methanolic extract of Vernonia amygdalina (MEVA) in an experimental model of tert‐butyl hydroperoxide (t‐BHP)–induced human erythrocyte lysis in vitro. Haemolysis was induced by incubating erythrocytes with t‐BHP (2 and 3 mM) in vitro. Samples of erythrocyte suspensions were removed at different intervals over a 6‐h period, and the degree of haemolysis was measured. The anti‐haemolytic effect of MEVA at 25–150 µg ml^–1 concentrations on the samples were assessed and compared with Triton X‐100. Administration of t‐BHP at 2‐ and 3‐mM concentrations significantly (p < 0.05) induced erythrocyte lysis by 37.5% and 31.4%, respectively. The addition of MEVA, however, reduced t‐BHP–induced erythrocyte lysis significantly (p < 0.05) by 39.3%, 48.4%, 67.3% and 73.4% at 25, 50, 100 and 150 µg ml^–1 concentrations, respectively. MEVA likewise protected against t‐BHP–induced lipid peroxidation significantly (p < 0.05) at 100 and 150 µg ml^–1 by the fourth hour and non‐significantly (p > 0.05) at all concentrations by the sixth hour. The reduced glutathione level was, however, increased with the administration of t‐BHP, while a delayed addition of MEVA had no protective effect on the t‐BHP–induced cell lysis. These findings therefore suggest that MEVA may have protective antioxidant properties, making it suitable for incorporation into food and drug products. Copyright © 2012 John Wiley & Sons, Ltd.     

Replicated high-density genetic maps of two great tit populations reveal fine-scale genomic departures from sex-equal recombination rates

Linking variation in quantitative traits to variation in the genome is an important, but challenging task in the study of life-history evolution. Linkage maps provide a valuable tool for the unravelling of such trait−gene associations. Moreover, they give insight into recombination landscapes and between-species karyotype evolution. Here we used genotype data, generated from a 10k single-nucleotide polymorphism (SNP) chip, of over 2000 individuals to produce high-density linkage maps of the great tit (Parus major), a passerine bird that serves as a model species for ecological and evolutionary questions. We created independent maps from two distinct populations: a captive F2-cross from The Netherlands (NL) and a wild population from the United Kingdom (UK). The two maps contained 6554 SNPs in 32 linkage groups, spanning 2010 cM and 1917 cM for the NL and UK populations, respectively, and were similar in size and marker order. Subtle levels of heterochiasmy within and between chromosomes were remarkably consistent between the populations, suggesting that the local departures from sex-equal recombination rates have evolved. This key and surprising result would have been impossible to detect if only one population was mapped. A comparison with zebra finch Taeniopygia guttata, chicken Gallus gallus and the green anole lizard Anolis carolinensis genomes provided further insight into the evolution of avian karyotypes.     

Autonomic neuropathy in Fabry disease: a prospective study using the Autonomic Symptom Profile and cardiovascular autonomic function tests

Background  

Fabry patients have symptoms and signs compatible with autonomic dysfunction. These symptoms and signs are considered to be due to impairment of the peripheral nervous system, but findings indicative of autonomic neuropathy in other diseases, such as orthostatic intolerance and male sexual dysfunction, are infrequently reported in Fabry disease. The aim of our study was to investigate autonomic symptoms and cardiovascular autonomic function in a large cohort of male and female Fabry patients.