Detection of African horse sickness virus in Culicoides imicola pools using RT‐qPCR

African horse sickness (AHS) is an infectious, non‐contagious arthropod‐borne disease of equids, caused by the African horse sickness virus (AHSV), an orbivirus of the Reoviridae family. It is endemic in sub‐Saharan Africa and thought to be the most lethal viral disease of horses. This study focused on detection of AHSV in Culicoides imicola (Diptera: Ceratopogonidae) pools by the application of a RT‐qPCR. Midges were fed on AHSV‐infected blood. A single blood‐engorged female was allocated to pools of unfed nulliparous female midges. Pool sizes varied from 1 to 200. RNA was extracted and prepared for RT‐qPCR. The virus was successfully detected and the optimal pool size for the limit of detection of the virus was determined at a range between 1 to 25. Results from this investigation highlight the need for a standardized protocol for AHSV investigation in Culicoides midges especially for comparison among different studies and for the determination of infection rate.     

Use of the score test as a goodness-of-fit measure of the covariance structure in genetic analysis of longitudinal data

Model selection is an essential issue in longitudinal data analysis since many different models have been proposed to fit the covariance structure. The likelihood criterion is commonly used and allows to compare the fit of alternative models. Its value does not reflect, however, the potential improvement that can still be reached in fitting the data unless a reference model with the actual covariance structure is available. The score test approach does not require the knowledge of a reference model, and the score statistic has a meaningful interpretation in itself as a goodness-of-fit measure. The aim of this paper was to show how the score statistic may be separated into the genetic and environmental parts, which is difficult with the likelihood criterion, and how it can be used to check parametric assumptions made on variance and correlation parameters. Selection of models for genetic analysis was applied to a dairy cattle example for milk production.     

Respiration in the filarial nematode Brugia pahangi

Glucose-supported O2 uptake in the filarial nematode Brugia pahangi was partially inhibited by antimycin A (30-40%), with the remaining activity being sensitive to o-hydroxydiphenyl or salicylhydroxamic acid (SHAM). The production of CO2 by B. pahangi in the presence of D-glucose was stimulated by O2; the stimulation of CO2; the stimulation of CO2 production was sensitive to antimycin A. The O2 dependencies of respiration showed that the apparent O2 affinity for B. pahangi was diminished in the presence of antimycin A; O2 thresholds for inhibition of respiration were observed which showed that the alternative electron transport pathway was less sensitive to inhibition at elevated O2 concentrations. H2O2 production and its excretion could be detected in whole B. pahangi; higher rates were observed in the presence of the uncoupler carbonyl cyanide m-chlorophenylhydrazone. The effects of inhibitors on H2O2 production suggest two sites of H2O2 production, one associated with the classical antimycin A-sensitive pathway, the other with the alternative respiratory pathway. The similarity in the O2 dependencies of H2O2 production and respiration may indicate that H2O2 production is involved in O2-mediated toxicity. Succinate and malate respiring sub-mitochondrial particles of B. pahangi produced O2.- radicals at a site on the antimycin A-sensitive respiratory pathway. Inhibition of the alternative electron pathway by SHAM was unusual; sub-millimolar concentrations markedly stimulated respiration, H2O2 production and O2.- production by 30, 20 and 25%, respectively, whereas higher concentrations (greater than 2.5 mM) inhibited respiration by 75% and H2O2 and O2.- production by up to 85%.     

Enhanced glutamate,IP3 and cAMP activity in the cerebral cortex of Unilateral 6-hydroxydopamine induced Parkinson's rats: Effect of 5-HT,GABA and bone marrow cell supplementation

Parkinson's disease is characterized by progressive cell death in the substantia nigra pars compacta, which leads to dopamine depletion in the striatum and indirectly to cortical dysfunction. Increased glutamatergic transmission in the basal ganglia is implicated in the pathophysiology of Parkinson's disease and glutamate receptor mediated excitotoxicity has been suggested to be one of the possible causes of the neuronal degeneration. In the present study, the effects of serotonin, gamma-aminobutyric acid and bone marrow cells infused intranigrally to substantia nigra individually and in combination on unilateral 6-hydroxydopamine induced Parkinson's rat model was analyzed. Scatchard analysis of total glutamate and NMDA receptor binding parameters showed a significant increase in B_max (P < 0.001) in the cerebral cortex of 6-hydroxydopamine infused rat compared to control. Real Time PCR amplification of NMDA2B, mGluR5, bax, and ubiquitin carboxy-terminal hydrolase were up regulated in cerebral cortex of 6-hydroxydopamine infused rats compared to control. Gene expression studies of GLAST, ά-Synuclien and Cyclic AMP response element-binding protein showed a significant (P < 0.001) down regulation in 6-OHDA infused rats compared to control. Behavioural studies were carried out to confirm the biochemical and molecular studies. Serotonin and GABA along with bone marrow cells in combination showed reversal of glutamate receptors and behaviour abnormality shown in the Parkinson's rat model. The therapeutic significance in Parkinson's disease is of prominence.