Effects of neonatally administered chlorpromazine and reserpine on the responsiveness of rat hepatic drug-metabolising enzymes to testosterone in adult life

The effects of neonatally administered chlorpromazine and reserpine on the response of rat hepatic drug-metabolising enzymes to testosterone in adult life have been investigated using the chlorinated cyclodiene substrate DME. Neonatal treatment with chlorpromazine and reserpine had effects on the metabolism of DME similar to, but not as pronounced as, those of castration when adult. The effects of adult castration of male rats on hepatic microsomal metabolism of DME were fully reversed by treatment with testosterone propionate, with metabolism being restored to that of a control intact male. However, testosterone propionate treatment of either intact or castrated adult males that had received neonatal reserpine or chlorpromazine did not restore levels of metabolism to those characteristic of control adult male rats. These results suggest that neonatally administered chlorpromazine and reserpine alter the sensitivity of hepatic drug-metabolising enzymes to the actions of testosterone in adult life.     

A chemomechanical method for caries removal

Over recent years the dental profession has shifted towards practising preventive dentistry and adopting more conservative and tooth-preserving procedures. Such progression is considered to be a response to the decline in the level of dental caries and advances in materials science. This shift in caries management will no doubt continue over the coming decades, based on rational clinical and scientific principles. Chemomechanical caries removal involves the application of a solution that selectively softens the carious dentine, thus facilitating its removal. This limits the removal of sound tooth structure, the cutting of open dentinal tubules, pulpal irritation and pain compared with conventional mechanical methods.     

Dummies and the sudden infant death syndrome.

The association between dummy use and sudden infant death syndrome (SIDS) was investigated in 485 deaths due to SIDS in the postneonatal age group and compared with 1800 control infants. Parental interviews were completed in 87% of subjects. The prevalence of dummy use in New Zealand is low and varies within New Zealand. Dummy use in the two week period before death was less in cases of SIDS than in the last two weeks for controls (odds ratio (OR) 0.76, 95% confidence interval (CI) 0.57 to 1.02). Use of a dummy in the last sleep for cases of SIDS or in the nominated sleep for controls was significantly less in cases than controls (OR 0.44, 95% CI 0.26 to 0.73). The OR changed very little after controlling for a wide range of potential confounders. It is concluded that dummy use may protect against SIDS, but this observation needs to be repeated before dummies can be recommended for this purpose. If dummy sucking is protective then it is one of several factors that may explain the higher mortality from SIDS in New Zealand than in other countries, and may also explain in part the regional variation within New Zealand.     

Hypersensitivity reaction to single contrast barium meal studies in children

We report two children who developed hypersensitivity reactions of varying severity following barium meal examination, the more severe of which was associated with documented severe food allergy. For children with this risk factor, contrast studies should be performed only where facilities and personnel are available for immediate resuscitation of all sizes of child. For children such as these, consideration should be given to the use of pure barium sulphate.     

Surgical treatment of aortic valvular disease in rheumatoid arthritis.

Two patients with severe rheumatoid arthritis and aortic regurgitation, developed progressive symptoms of left ventricular failure. Symptoms were inadequately controlled by medical therapy. Surgical treatment was at first considered with great reluctance because of the theoretical risk of operative and postoperative complications in patients with a diffuse disease of connective tissue. The suspected complications did not materialize. Valvular replacement should be considered in patients with severe valvular disease associated with rheumatoid arthritis.     

Testicular neonatal imprinting of sex dependent differences in hepatic foreign compound metabolism in the rat

A dimethylated chlorocyclodiene epoxide (DME)¹ is metabolized by adult male rat liver enzymes to produce two g.l.c. detectable metabolites M1 and M2. Liver enzymes from adult female rats metabolize DME producing only metabolite M1 in detectable quantities. This apparent qualitative sex difference in the metabolism of DME is first manifest between the ages of 35 and 45 days. Liver enzymes from rats of both sexes younger than 35 days metabolize DME in a qualitatively similar manner. The actions of the testes in the development of this apparent qualitative sex difference are exerted between the ages of 7 and 14 days. Castration of male rats at and before the age of 7 days results in the expression of a typically feminine pattern of metabolism of DME by liver enzymes in adult life. Castration of male rats after the age of 14 days does not prevent adult liver enzymes from exhibiting a basically masculine pattern of DME metabolism. At ages between 7 and 14 days castration has a graded effect on the metabolism of DME displayed by liver enzymes in adult life. These results suggest that testicular androgens do not play a direct role at puberty and in adulthood in the expression of the ability of liver enzymes to produce metabolite M2, but that the apparent qualitative sex dependent difference in DME metabolism is determined primarily by neonatal imprinting by testicular androgens.     

Canadian Helicobacter Study Group Consensus Conference on the Approach to Helicobacter pylori Infection in Children and Adolescents.

Gastric infection with Helicobacter pylori is common in both children and adults, but children are considerably less susceptible to peptic ulcers and other pathological sequelae. As a result, the risk to benefit ratio of diagnostic studies and therapeutic regimens for H pylori in adults are likely different from those in pediatric populations. These guidelines for the management of pediatric H pylori infection, developed by the Canadian Helicobacter Study Group, are designed to identify when the diagnosis and treatment of H pylori may improve patient care. Given the low prevalence of this infection in Canada, it is important to recognize that indiscriminate testing and treatment programs in children are not recommended, and indeed may threaten the optimal care of children. Diagnostic tests should be employed judiciously and be reserved for children who are most likely to derive measurable benefit, such as those likely to have peptic ulcer disease. At this time a test and treat strategy in children cannot be considered prudent, evidence based or cost effective. It is appropriate to limit diagnosis and treatment to children and adolescents in whom H pylori has been identified during endoscopic investigation.     

Effects of hypophysectomy on sex differences in the induction and depression of hepatic drug-metabolizing enzymes in the rat

The role of the pituitary gland in the effects of treatment with phenobarbital, methylcholanthrene and morphine on hepatic drug metabolism in adult male and adult female rats has been investigated. A marked sex difference in the effects of treatment with these three compounds on hepatic drug metabolizing enzymes in intact adult rats was observed. No sex differences in the effects of phenobarbital methylcholanthrene or morphine on hepatic drug metabolizing enzymes were observed after treatment of hypophysectomized adult male and hypophysectomized adult female rats. The results indicate that the pituitary gland plays an important role in the determination of sex differences in the response of hepatic drug metabolizing enzymes to inducing agents.