The potential signalling pathways which regulate surface changes induced by phytohormones in the potato cyst nematode (Globodera rostochiensis)

It has been demonstrated that the surface lipophilicity of the plant-parasitic nematode Globodera rostochiensis decreases when infective larvae are exposed to the phytohormones indole-3-acetic acid (auxin) or kinetin (cytokinin). In the present study, it was shown that inhibition of phospholipase C (PLC) or phosphatidylinositol 3 kinase (PI3-kinase) reversed the effect of phytohormones on surface lipophilicity. The signalling pathway(s) involved in surface modification were investigated using 'caged' signalling molecules and stimulators or inhibitors of different signalling enzymes. Photolysis of the 'caged' signalling molecules, NPE-caged Ins 1,4,5-P3, NITR-5/AM or caged-cAMP to liberate IP3, Ca2+ or cAMP respectively, decreased the surface lipophilicity. Activation of adenylate cyclase also decreased the surface lipophilicity. In contrast, inhibition of PI3-kinase using Wortmannin, LY-294002 or Quercetin, and inhibition of PLC using U-73122 all increased the surface lipophilicity. Two possible signalling pathways involved in phytohormone-induced surface modification are proposed.

Effects of phytohormones on the surfaces of plant-parasitic nematodes

The direct effects of phytohormones (auxin and kinetin) and root diffusates on the surface lipophilicity of the plant parasitic nematodes Globodera rostochiensis and Meloidogyne incognita were investigated. The fluorescent lipid probe AF18 (5-N(octodecanoyl) aminofluorescein) was used to detect surface changes. Root diffusates increased AF18 uptake by G. rostochiensis while it had no effect on M. incognita. Kinetin and auxin decreased AF18 uptake in G. rostochiensis, while they had the opposite effect on M. incognita. Auxin/kinetin ratio was also found to be important in triggering the surface changes, especially at high concentrations. Whether plant nematodes have auxin and/or kinetin binding proteins is discussed as well as the mechanism behind the surface lipophilicity changes due to root diffusates and phytohormones.

The changing role of internal auditors in health care

Two surveys of directors of internal auditing in health care conducted in 1990 and 1998 found that healthcare internal auditors are spending proportionately more time on management and operational improvement activities and less time on traditional financial/compliance activities. The average staff size has remained relatively constant, but salaries at all levels of experience have risen. More importantly, the tenure of healthcare internal auditors has increased significantly since 1990. The profile of the healthcare internal auditing director also has changed. The director is older, more experienced, and has held the position for twice as long as was the case in 1990. On the other hand, the director is more stressed and less satisfied with compensation.

Parasitism and the platyhelminthes

by Graeme C. Kearn, Chapman & Hall, 1998. pound115.00 (xii +544 pages) ISBN 0 412 80460 3.

Profile of internal auditors in health care

The internal auditor is an important management resource for maintaining control over operations. As the importance of healthcare cost management grows, so does the potential contribution of the internal auditor. A recent study examines what internal auditors do, what backgrounds they have, what salaries they receive, and what their career attitudes are.