The binding of 3H-labelled oestradiol- and progesterone-receptor complexes to hypothalamic chromatin of male and female sheep

Chromatin isolated from hypothalamic nuclei of sexually mature entire male and female sheep was linked to cellulose in u.v. light. The saturation binding of 3H-labelled oestrogen- and progesterone-receptor complexes, prepared by (NH4)2SO4 precipitation from the 105000g supernatant of hypothalamic cytosol, was then measured in vitro in 0.15m-KCl. Saturation binding was also measured after extraction of histones and masking acidic proteins. Salt + urea was observed to be more effective than guanidine hydrochloride in unmasking receptor acceptor sites, and the binding of labelled receptor complexes to dehistonized unmasked chromatin was shown to be largely resistant to 0.4m-KCl extraction. Whereas extents of receptor-complex binding were similar to published values for comparable preparations of hen oviduct chromatin, no sex-related difference was observed. However, binding of progesterone-receptor to chromatin was greater than that of oestradiol-receptor. Binding also increased more after removal of histones and masking acidic proteins, suggesting the presence of a greater number of progesterone-receptor acceptor sites in hypothalamic chromatin than of estradiol-receptor acceptor sites. The failure to demonstrate a sex-related difference in oestradiol-receptor binding to hypothalamic chromatin in vitro is discussed.

Comparison of the effects of beeswax: trioctanoin and trioctanoin vehicles on 3-methylcholanthrene, benzo[a]pyrene, and 7,12-dimethylbenz[a]anthracene subcutaneous carcinogenesis in three strains of mice and one hybrid

Subcutaneous tumor induction with three dose levels of 3-methylcholanthrene (MCA), benzo[a]pyrene (BP), and 7,12-dimethylbenz[a]anthracene (DMBA) in two vehicles was studied in C3H/Anf Cum, C57BL/6 Cum, DBA/2J, and (C57BLXC3H/Anf)F1 (BC3F1/Cum) mice. Median tumor dose levels were significantly lower when the three carcinogens were suspended in trioctanoin. When beeswax: trioctanoin (B:T) was used as a vehicle, the three carcinogens differed in their abilities to be absorbed or solubilized from the vehicle by the three strains of mice and the hybrid. In C3H/Anf mice, BP in B:T failed to produce tumors. In BC3F1 mice, no tumors were produced by MCA, BP, or DMBA in B:T. In C57BL/6 mice, no tumors were produced with DMBA or MCA in B:T. In DBA/2 mice, no tumors were produced by BP or MCA in B:T. These results indicated that the interpretation of tumor induction results obtained with B:T vehicle may be related to the conditions of bioassay rather than to the carcinogenic potential of a compound.

[A malignant tumour in the female genital tract of Pachygnatha clercki Sundevall, 1823 (Arachnida, Araneae, Tetragnathidae)]

A first case of genuine neoplasm is reported in the order Araneida. This epithelial tumor, proceeding from oviduct ends, invades uterus; malignancy is strongly supported by cell structure and extensive local behavior.

Serum lipid changes in medical students

Changes in serum lipids and reasons for these changes were evaluated in 108 medical students, Class of 1975. Serum cholesterol and serum triglycerides were analyzed in their freshman and senior years. A self-administered questionnaire was used to determine if the education in medical school or the knowledge of their freshman lipid vales motivated the students to change their diet and exercise habits. During this four-year period, there was a statistically significant decrease in the mean cholesterol levels (-10 mg. per 100 ml.), while the values increased slightly but not significantly for mean triglyceride (3 mg. per 100 ml.) and weight (2 lb.). Students with abnormal lipid values in their freshman year changed their diets more frequently than those with normal values. When the students were grouped by their change in diet and exercise habits, the largest decrease in lipid values was in those who changed both their diet and exercise. However, the changes in lipid values could not be totally attributed to the students' change in habits. Results suggest that detection and education may contribute to changes in certain risk factors associated with coronary heart disease in young medical students.

Histologic study of elastin-like fibers in the attached gingiva

Fifty-seven specimens of attached gingiva have been stained for elastic fibers. The number of elastin-like fibers in the papillary layer and reticular layer of the lamina propria have been scored using a scale of 0 to 3. Using similar H & E stained sections, the amount of inflammation was also scored. The presence of elastinlike fibers in the reticular layer of lamina propria of the attached gingiva has been described. Fibers have been found in the walls of blood vessels and they have been found intermingled with the dense collagenous tissue. While an attempt was made to establish a relationship between the relative number of elastin-like fibers and patient's age or degree of inflammation, lack of sufficient number of specimens at age troups precluded this.

[Ultrastructure of the clypeal gland of male spiders of the genus Argyrodes (Theridiidae)]

The electronomicroscopic study of the clypeal gland of Argyrodes gibbosus (Lucas, 1846) shows a secretion which flows through excretory, intracellular canaliculi which pass through the integument.

Metabolic effects of exercise. I. Effect of exercise on serum lipids and lipogenesis in rats

To evaluate the metabolic effects of exercise, three groups of exercised male rats were compared to their sedentary controls at the end of 10 wk of voluntary exercise in rodent activity cages. Exercises rats consumed more food than sedentary rats but had greater weight gain only at the higher levels of activity. Exercised rats had significanlty lower serum triglycerides and higher values of adipose tissue alpha-glycerophosphate dehydrogenase activity. At higher levels of physical activity, the exercised rats enhibited larger adrenal glands and lower values of hepatic glucose-6-phosphate dehydrogenase. It is concluded that specific levels of voluntary exercise are needed to achieve specific metabolic effects.

Metabolic effects of exercise. II. Residual metabolic effects of exercise in rats

This report described the duration of changes in serum lipids, adrenal weight and hepatic G-6-PD activity in rats following the termination of 10 weeks of voluntary activity in a revolving drum. Exercised rats had lower weight gain, larger adrenal glands, lower serum cholesterol, lower serum triglycerides and lower liver glucose-6-phosphate dehydrogenase (G-6-PD) activity than the sedentary controls. The differences between exercise and control rats in adrenal gland weight, body weight and G-6-PD tend to disappear within 3 wk after termination of the exercise. These experiments provide evidence that exercise can affect lipid metabolism and have a beneficial effect on the lowering of serum lipids. It also shows that this effect will persist for up to 3 wk after the exercise is terminated, under the experimental conditions of this study.

The participation of aortic proteins in the formation of complexes between low density lipoproteins and intima-media extracts

SUMMARY

A factor of protein nature that forms specific complexes with low density lipoproteins (LDL) has been detected in extracts of aortic intima-media from men and rabbits. Although the formation of complexes is maximal at low ionic strength, it is still observed under physiological conditions. Gel electrophoresis of the complex formed between the extracts and LDL proteins indicates that the insoluble material is an aggregate of the lipoproteins with some of the proteins present in the extracts. Pretreatment of the intima-media extract with proteases greatly diminishes its complexing ability. The interaction was also observed between the extracts and sera. The sera from patients with myocardial infarct formed more insoluble complexes than the sera from a control group. The lipoprotein complexing agent was found in intima-media of aorta and coronary arteries but not in that of veins, pulmonary arteries or in the adventitia of arteries or veins.

Automated Simultaneous Turbidimetric Determination of Cholesterol in β- and pre-β-Lipoproteins

An automated method is described for simultaneously determining cholesterol in serum β- and pre-β-lipoprotein fractions. This fast, reproducible, accurate method depends on the ability of β- and pre-β-lipoproteins to form insoluble complexes with polyanionic polysaccharides such as heparin. Values obtained by this method and by similar manual methods described in the literature agree well. This method is extremely useful in mass screening for hyperlipidemias; in certain cases it may be more useful than the determination of only cholesterol or triglycerides.

Effect of lipids on growth hormone secretion in humans

To determine the effect of elevations of plasma lipids on growth hormone secretion in humans, paired insulin hypoglycemia tests and paired arginine infusion tests were performed on eight and six normal female volunteers respectively. On 1 of the 2 test days for each growth hormone stimulus, subjects were given 60 g corn oil (Lipomul) 3 hr before testing followed by intravenous heparin (5000 U) at the time of insulin or arginine administration. Lipomul plus heparin administration inhibited both insulin- and arginine-induced plasma HGH elevations with almost complete suppression of the response to arginine. The plasma HGH (human growth hormone) inhibition was associated with elevation in plasma triglycerides and inhibition of plasma FFA (free fatty acid) depression after insulin or arginine. Neither the hypoglycemic response to insulin nor the blood glucose and plasma immunoreactive-insulin responses to arginine were altered by Lipomul plus heparin administration. In four additional subjects in whom Lipomul was given without heparin, the elevated plasma triglyceride values were not associated with suppression of arginine-induced plasma HGH elevations. In the same four subjects, heparin administration without Lipomul neither suppressed arginine-induced plasma HGH elevations nor prevented the depression in plasma FFA after arginine as much as when Lipomul plus heparin had been given. These latter observations suggest that the elevation in plasma FFA was responsible for suppression of growth hormone secretion by Lipomul plus heparin. These studies indicate a possible role of plasma FFA in regulation of growth hormone secretion.

Bacteriological and shelf-life characteristics of canned, pasteurized crab cake mix

The bacteriological spoilage characteristics of a canned, pasteurized crab cake mix product stored at various temperatures were investigated. A large number of bacteria, both mesophilic and psychrophilic, survived the pasteurization process. Bacillus and Micrococcus were found to predominate when the product was stored at 30 C (86 F) and 18 C (64 F), whereas Alcaligenes predominated at 2 C (36 F). The product was found to be free of Escherichia coli. Bacterial counts, trimethylamine nitrogen, volatile reducing substances, and ammonia determinations were evaluated as indices of quality for the product. Close correlation was observed between bacterial counts, volatile reducing substance values, and organoleptic tests when the product was stored at 30 C (86 F). The shelf-life of the product was approximately 6 months at 2 C (36 F), 4 days at 18 C (64 F), and 27 hr at 30 C (86 F).