Lipid peroxidation and protein thiol depletion are not involved in the cytotoxicity of N-hydroxy-2-acetylaminofluorene in isolated rat hepatocytes

Freshly isolated rat hepatocytes were used to study the mechanism of cell death induced by N-hydroxy-2-acetylaminofluorene (N-OH-AAF). Exposure to 1.0 mM N-OH-AAF resulted in more than 90% cell death (as measured by LDH leakage) of hepatocytes isolated from male rats within 6 hr. Only 36% of the hepatocytes isolated from female rats died within this period. When inorganic sulfate was omitted from the incubation medium, a 6 hr exposure to 1.0 mM N-OH-AAF resulted in only 40% cell death of male hepatocytes. These findings are in accordance with the sex difference and sulfation dependence of N-OH-AAF hepatotoxicity observed in the rat in vivo. N-OH-AAF decreased glutathione (GSH) in male hepatocytes in a concentration-dependent manner. This GSH consumption was only partly dependent on the presence of inorganic sulfate. No lipid peroxidation was observed during N-OH-AAF exposure; N-OH-AAF even prevented endogenous and diethyl maleate (DEM)-induced lipid peroxidation. No reduction of free protein thiol groups was found after exposure to N-OH-AAF, even after 75% cell death had occurred. A reduction of protein thiols after N-OH-AAF exposure was observed in GSH depleted hepatocytes (obtained by DEM plus vitamin E pretreatment). Under these conditions N-OH-AAF-induced cell death occurred earlier. Therefore, GSH protects against protein thiol depletion by N-OH-AAF in control cells. N-OH-AAF-induced cell death was preceded by a loss of intracellular ATP. It is concluded, therefore, that neither lipid peroxidation nor depletion of protein thiols, but possibly loss of intracellular ATP, is involved in the sulfation-dependent cytotoxic mechanism of N-OH-AAF in isolated rat hepatocytes.     

Doppler Ultrasound in Canine Pregnancy

Objective. The aim of this article is to review the current knowledge of Doppler ultrasound in canine pregnancy. A brief introduction of Doppler principles and their applications in human obstetrics is also included. Methods. A review of the peer‐reviewed published literature was conducted of the articles pertaining to the use of Doppler ultrasound in canine pregnancy, general Doppler principles, and Doppler applications in human obstetrics. Results. In bitches, Doppler ultrasound has been used to assess ovarian, uterine, umbilical, fetal aorta, common carotid artery, and fetal caudal vena cava blood flow during normal gestation. Most of these vessels increase their blood flow during normal pregnancy. The resistive index and systolic/diastolic ratio of the uterine arteries have been recently described in an experimental pharmacologically induced model of abnormal canine gestation. Both indices progressively increase up to abortion, probably because of progesterone deprivation. Moreover, resistive index abnormalities have been found in canine cases of spontaneous abnormal gestations as described in human medicine. Conclusions. Doppler ultrasound is a useful method for assessing development of the placental and fetal circulation during normal and abnormal canine pregnancy. Further studies are still necessary to widely use this technique in clinical practice.     

Child abuse and dentists

A questionnaire on the recognition and reporting of child abuse was sent to a random sample of Dutch dental practitioners (N = 250). The response rate was 54%. Eighty-six percent had never seen a case of child abuse. The percentage of dentists reporting a (suspicious) case of child abuse (6%) was lower than the percentage of dentists detecting a case of suspicious child abuse (14%). The most important reason for this discrepancy seems to be a lack of knowledge and/or skills to properly identify child abuse. More professional education about child abuse is desired.     

An impending crisis in the provision of histopathology expertise for mouse functional genomics

The generation of new mouse models of human disease is accelerating rapidly, due to the completion of whole‐genome sequencing efforts and technological advances in the manipulation of the mouse genome. We sought to investigate manpower issues in the provision of histopathology expertise for mouse functional genomics and compared this to the perceived demand from principal investigators (PIs). Through the European Commission (EC)‐funded PRIME pathology training initiative, two questionnaires were devised to collect information from pathologists and EC‐funded PIs on the current provision of mouse histopathology expertise in Europe and the demands for this service. We find that pathological analysis is being performed almost exclusively by professionally qualified pathologists, generally employed in clinical diagnostic posts, where the work is undertaken as collaboration outside of their contractual commitments but without previous training in veterinary or comparative pathology. The results indicate that there is a lack of both trainees and provision of specialist training in this field. Unsurprisingly, the availability of diagnostic expertise and advice falls far short of the number of genetically engineered mice (GEM) being generated for analysis. We analyse these results with reference to previous studies and discuss solutions for the future recruitment, training and funding for pathologists in mouse functional genomics in Europe. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.