Nutrition education of young women.

White women aged 25-34 years (n 264) from the lower socio-economic classes (C2, D and E) were classified according to their motivation in respect of health and their educational attainment and arithmetical ability. They were randomly allocated to three groups. One group (test) was given a course in basic nutrition consisting of a video and booklet, each embellished with motivational material. Those classed as of low ability also received the training material in simplified format. A second group (control) received a video and booklet with no motivational or simplified materials. The third group (baseline) received no tuition and represented a control of publicly available information during the period of the experiment. The participants answered a series of questions by administered questionnaire to measure their nutritional knowledge before and one week after they viewed the video programme. All participants achieved significantly higher scores at the second questionnaire. The test and control groups achieved significantly higher scores than the baseline group but there was no significant difference between the test and control groups. The presentation of motivational or simplified materials had no significant effect on learning ability though those classified as more highly motivated and of higher ability achieved higher scores at each questionnaire. The results indicate that young adult females can be taught basic nutrition irrespective of their motivation or ability.

Studies on the induction of cholangiofibrosis by coumarin in the rat.

The histogenesis of coumarin-induced cholangiofibrosis in the rat has been determined. Proliferation of ductal structures was preceded by extensive damage to hepatocytes in the centrilobular region. Focal proliferation of ducts and fibrous tissue was present at 3 months and typical areas of cholangiofibrosis at 6 months. By 18 months the lesion was extensive and contained areas showing bizarre histological features suggestive of malignancy although no evidence of extra-hepatic metastasis was found. The lesion in animals returned to standard diet showed varying degrees of involution with extensive atrophy and fibrosis. A number of parameters of hepatic mixed function oxidase activity were reduced during the initial treatment period, at later times there was recovery of some microsomal enzyme activities. The activity of gamma-glutamyltransferase and the hepatic content of non-protein sulphydryl groups, in contrast, were raised throughout the treatment period.

Comparative metabolism of BHA, BHT and other phenolic antioxidants and its toxicological relevance.

Following oral administration, butylated hydroxyanisole (BHA) is absorbed and rapidly excreted by the rat, rabbit and man, with little evidence of long-term tissue storage. The major metabolic pathways for BHA are conjugation (phase 2) reactions, oxidative metabolism (O-demethylation) being relatively unimportant. In the dog, the extent of absorption and urinary excretion is less, and oxidative metabolism is more important than in other species. In contrast, butylated hydroxytoluene (BHT) is cleared less rapidly from most species, enterohepatic circulation being partly responsible for the delay. Tissue accumulation is also greater for BHT than for BHA. Oxidative metabolism (phase 1 reactions) mediated by the microsomal monooxygenase system is the major route for BHT degradation; oxidation of the ring methyl group predominates in the rat, rabbit and monkey, and oxidation of the tert-butyl groups in man. Gallates and 2-tert-butylhydroquinone are mainly metabolized by non-oxidative pathways (methylation or conjugation with sulphate and glucuronic acid). The different biological properties of these compounds may be related to the differences in their absorption and metabolic disposition. Thus, whereas BHT, which is metabolized by oxidation reactions, is an inducer of the microsomal mono-oxygenase system, the other phenolic antioxidants, including BHA, are only weak inducers.

Sister chromatid exchange (SCE) analysis in 106 control individuals.

PIP: This study was aimed at obtaining baseline data on the degree of variability of sister chromatid exchange (SCE) values in 106 individuals. There were highly significant differences between individuals and between replicate serum cultures within individuals in SCE frequencies. Females had significantly higher SCE frequencies than males, and cigarette smoking significantly increased such values after correction for sex. On the basis of this study, the following recommendations are proposed for future studies monitoring SCE frequencies in control and exposed populations: 1) subjects should be matched by sex and smoking status; 2) 50 cells per individual with 25 from 2 replicate cultures is a suitable sample size; 3) either the original data or the means should be transformed to logarithms for analysis; 4) the dispersion test should be carried out and the H statistic (variance/mean) should be reported; 5) differences between control and exposed groups can be analyzed either by analysis of variance or nonparametric methods; 6) the sample size should be based on considerations of the significance level required and interindividual variability; 7) concurrent controls are advisable when using statistics based on background incidences; and 8) quality control methods should be applied to routine collection of background control data.^ieng

Sustained induction of hepatic xenobiotic metabolising enzyme activities by phenobarbitone in C3H/He mice: relevance to nodule formation.

Phenobarbitone (PB) was administered to male C3H/He mice at a dose of 85 mg/kg/day in a semisynthetic diet for up to 90 weeks. Throughout the treatment period a sustained induction of a number of parameters of hepatic Phase I and Phase II xenobiotic metabolism was observed. Histological examination revealed hypertrophy of the centrilobular cells of the liver lobule in PB treated mice and after 25 weeks small basophilic nodules were found in control and PB treated animals. In addition eosinophilic nodules, which were often large, developed in PB treated mice. Xenobiotic metabolising enzyme activities in large excised nodules after 70 or 90 weeks of PB treatment were either similar to or greater than those present in surrounding host tissue. Both phenobarbitone- and polycyclic hydrocarbon-type mixed function oxidase enzyme activities were induced in large nodules. In conclusion, PB produced a sustained induction of xenobiotic metabolising enzymes both in host tissue and in large eosinophilic nodules. The formation of these nodules in C3H/He mice was thus not associated with any failure of induction of hepatic xenobiotic metabolism.

Quantitative comparisons of the pulmonary toxicity of tobacco and NSM smoke.

Smoking elicits a panacinar rise in pulmonary alveolar lysosomal activity that is thought to correlate with the irritancy of the smoke. Quantitative image analysis of lung sections stained histochemically for acid phosphatase indicates that tobacco smoke is significantly more irritant than NSM smoke.

Effect of glycerol on local and systemic carcinogenicity of topically applied tobacco condensate.

When glycerol was added to tobacco smoke condensate in acetone solvent, the topical carcinogenicity and the ability to produce epithelial hyperplasia in mice was reduced. Two doses of condensate were applied, combined with 2 concentrations of added glycerol. Age-standardized results show that glycerol reduced the incidence of tumours and malignant tumours and of hyperplasia in animals not developing skin tumours. The relative incidences of malignant tumours, benign tumours, hyperplasia and unaffected skin suggest that there is a sequential relationship (i.e. normal skin to hyperplasia to benign neoplasia to malignant neoplasia) which is impeded by glycerol. There was no systemic effect attributable to the condensate.

Studies on the local and systemic carcinogenicity of topically applied smoke condensate from a substitute smoking material.

The topical carcinogenicity to mouse skin of smoke condensates obtained from a tobacco substitute (NSM), alone or in combination with tobacco, has been compared with condensate from tobacco and with acetone, the solvent used. Sixteen different types of cigarette were used to make the condensates, and the age-standardized results have been analysed according to the Weibull distribution model. The results show that NSM condensate has less than 25% of the potency of tobacco condensate (37% at 95% upper confidence limit), and that condensates from blends of NSM and tobacco are similarly reduced in activity. General pathology analysis failed to reveal abnormalities due to NSM.