Effect of high concentrations of lufenuron, pyriproxfen and hydroprene on Rhipicephalus (Boophilus) annulatus.

The activity of high doses of three insect growth regulators (IGRs), lufenuron (MATCH®), pyriproxfen® and hydroprene (Gentrol®), were tested on Rhipicephalus(Boophilus) annulatus adult females, eggs and larvae. Different concentrations of the IGRs were tested on eggs, larvae and adult ticks through immersion, larval packet and adult immersion bioassays, respectively. The tested IGRs did not show adulticidal activity against female ticks even at very high concentration. However, both hydroprene and pyriproxfen caused a significant decrease (P<0.05) in the reproductive indices of adult female ticks. Both lufenuron and pyriproxefen showed considerable ovicidal activity delaying the hatchability of the treated eggs until the 21st day and decreasing the hatchability percentages to 37.7% and 60.6% at concentrations ≥10X and ≥4X, respectively. Lufenuron (≥10X dose), hydroprene (≥4X dose) and pyriproxyfen (≥4X dose) induced highly significant larvicidal activity as they caused 100% mortality after 72 h of exposure. The oxidative profile of the hydroprene treated ticks had decreased glutathione peroxidase and increased malonaldehyde in comparison to the other IGR- treated and control untreated ticks. It is concluded that the IGRs did not show R. annulatus adulticidal effect, however, the deposited egg mass and its hatching percent decreased significantly when treated with hydroprene and pyriproxfen. The tested IGRs showed larvicidal activity against R. (B.) annulatus.

Primary care medicine using a pathways model.

The Faculty of Medicine, University of Suez Canal, Ismailia, Egypt is the newest medical school in Egypt and a member of the network of community orientated medical schools, with an emphasis on primary care medicine. The faculty is engaged in innovative approaches to curriculum content and design and to teaching methods and sites. The model presented here is an attempt to teach primary care medicine in a logical manner.

Glyceride synthesis by a cell-bound lipase from Aspergillus niger.

A cell-bound lipase from the mould Aspergillus niger was isolated and purified to homogeneity as judged by disc electrophoresis on a Sephadex G-75 column. Molecular weight determination and electrophoretic mobility (Rf value) indicated that the enzyme differed from that secreted extracellularly. The cell-bound lipase showed a higher capacity than the extracellular enzyme for glyceride synthesis, and reacted in an opposite manner in the synthetic reaction compared with the extracellular enzyme.