Biochemical effects of two promoters of hepatocarcinogenesis in rats

The effects of two promoters of hepatocarcinogenesis--phenobarbital and butylated hydroxytoluene (BHT)--on five hepatic biochemical parameters were examined in adult female rats. Phenobarbital given orally in two doses each of 110 mg/kg 21 and 4 hr before the rats were killed caused large increases in hepatic ornithine decarboxylase (ODC) activity and cytochrome P-450 content. Extending the number of phenobarbital treatments to five increased the hepatic enzyme induction and also caused a minor decrease in hepatic glutathione and a small increase in serum alanine aminotransferase activity. Two oral doses of 700 mg BHT/kg (20% of the LD50) caused hepatic DNA damage and induction of both ODC activity and cytochrome P-450 content. When the dose of BHT was reduced from 700 to 140 mg/kg no significant effects on the biochemical parameters were found. Both promoters of hepatocarcinogenesis were identified by their induction of ODC, a marker for promotional potential, but only BHT showed a potential for carcinogenic initiation. The biochemical parameters examined, particularly the alkaline elution technique for DNA damage, ornithine decarboxylase activity and serum alanine aminotransferase, may constitute a useful assay system for examining a compound's potential for carcinogenic initiation, carcinogenic promotion and cellular toxicity.     

Effect of chronic administration of different Bence Jones proteins on rat kidney

The role of Bence Jones proteins (BJPs) in the genesis of the renal dysfunction that develops in patients with multiple myeloma is not clearly defined. We previously evaluated renal function and morphology in a unique strain of rats (LOU/m) bearing tumors which synthesized BJPs with isoelectric points of 5.2, 4.3 and 6.7. Myeloma cast nephropathy developed in one tumor bearing group (pI 5.2), tubular necrosis was observed in another (pI 4.3), and renal function and histology remained normal in a third group (pI 6.7). To see if these renal outcomes were a function of the BJP being excreted or other factors which could be present in the tumor bearing animals, we have examined the effect of chronic intravenous administration of these three BJPs on renal function and histology in non-tumor-bearing LOU/m rats. Urine containing the BJP was collected from tumor bearing rats, sterilized by passage through a 0.2 mu millipore filter, concentrated to 50 mg/ml, and dialyzed extensively so as to remove material with a molecular weight less than 3500. Chronic indwelling-venous catheters were placed in non-tumor-bearing LOU/m rats and these rats were given 100 mg/day for five days of one of the three BJPs. Polyfructosan clearance (Cin) was measured prior to and following the five days of BJP administration. Renal histology was examined at the completion of the second Cin. In the pI 5.2 group (N = 6), a severe distal nephron cast nephropathy occurred and Cin fell from 2.88 +/- 0.24 to 0.90 +/- 0.17 ml/min (P less than 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)     

The Busselton children's survey, 1983. Body size from five to 16 years of age

In 1983, 1623 primary and secondary schoolchildren took part in a health survey which was organized by the Busselton Population Studies Group. Age, sex, weight, height and country of birth were recorded for each child. Where possible, the country of birth of parents and the occupation of the father were extracted from previous Busselton surveys of adults. Compared with Perth schoolchildren, the difference in the attained weight and height of Busselton children at any age was small. This was so even though the two communities differ in location (rural compared with metropolitan), in ethnic origin (mainly British compared with diverse origins) and, probably, in social-rank distribution. Data from the two communities showed that a similar small secular increase in height had occurred since 1970/1971. This increase averaged at 1.2 cm for children at each year of age in Busselton and 1.5 cm to 1.6 cm for children in Perth.     

Naloxone-reversible analgesia as a result of stimulation of the habenula in the rat

Electrical stimulation of rat habenular complex induces analgesia, evaluated by the tail-flick test, dependent on intensity of stimulation with a long post-effect, that is reversible by naloxone and without behavior effects at less that 400 mA. Bilateral destruction of habenula fails to provoke hyperesthesia but causes more marked long-term tolerance effects than in controls. Anatomy suggests that the habenula activates an inhibitory descending system in the spinal cord with a probable relay in the dorsal raphe and involving an endogenous opioid-dependent stage.     

Obese, overweight, desirable, ideal: where to draw the line in 1986?

In February 1985, the National Institutes of Health sponsored the Consensus Development Conference on the Health Implications of Obesity. The panel of experts concluded that height and weight tables based on mortality data and the body mass index (BMI) are helpful measures to determine the presence of obesity and the need for treatment. For the dietitian, however, practical concerns arise regarding which index to select. The usefulness of the BMI in patient education and contradictions between the 1959 and 1983 Metropolitan Life Insurance height-weight tables are discussed. A temporary solution is offered in light of the need for further investigation into morbidity experience at weights recommended in the 1983 table.     

Etiological heterogeneity in Hodgkin's disease: HLA linked and unlinked determinants of susceptibility independent of histological concordance

Forty-one multiplex families, from published sources and new data from the National Cancer Institute, segregating for Hodgkin's disease and HLA, have been studied. A reanalysis of these data strongly suggests a recessive mode of inheritance for susceptibility to Hodgkin's disease. The HLA haplotype sharing data between affected relatives demonstrate that approximately 60% of cases in multiplex families are due to an HLA-linked susceptibility gene, the remaining 40% being due to other familial factors. The data clearly support the hypothesis of etiological heterogeneity for Hodgkin's disease, with both HLA-linked and HLA-unlinked factors being responsible. Finally, there is an increased concordance of histological types between affected relatives, but this concordance seems independent of HLA sharing.