Detection of gonadotrophic hormones on isolated granulosa cells of the domestic hen, Gallus domesticus, by an immunohistochemical method

Two immunohistochemical methods were used to detect the presence of luteinizing hormone (LH) on the cells of chicken granulosa. Using a peroxidase-labelled anti-rabbit serum together with anti-chicken LH serum raised in rabbits, a strong positive response was obtained with granulosa cells from small and large pre-ovulatory follicles obtained from the mid-cycle. Similarly, by using an available antiserum to human follicle stimulating hormone (FSH), a slightly weaker response was obtained with cells from both large and small follicles. After incubating cells with ovine LH, ovine FSH and ovine prolactin, there was no detectable difference with the method used in reaction with their respective antisera to cells which had received no incubation, implying that chicken gonadotrophins were displaced only partially from their receptors by mammalian gonadotrophic hormones. Pre-incubation of the cells with human chorionic gonadotrophin gave negative results with anti-hCG serum. Using a fluorescent-labelled antibody method, similar results were obtained except that the distribution of the receptors on the granulosa cell for LH or FSH appeared to be different. With the LH, the fluorescence formed a halo around the cell in contrast to the overall fluorescence with FSH.     

Radioimmunoassay of a glycoprotein associated with malignancy

A glycoprotein associated with malignancy was purified from the 0.6M perchloric acid-soluble fraction of serum obtained from cancer patients. The purified glycoprotein contained sialic acid, which was responsible for binding to wheat-germ agglutinin-Sepharose. Gel electrophoresis showed one band with an apparent Mr of 50 000-55 000, and the isoelectric point was 4.4 +/- 0.1. The glycoprotein could be distinguished from carcinoembryonic antigen and alpha-fetoprotein. Iodination of this material with chloramine-T permitted development of a radioimmunoassay.     

Occurrence of Cyclopiazonic Acid in Peanuts

Samples of segregation 3 farmer stock peanuts from the 1980 southeastern United States growing season were analyzed for the presence of cyclopiazonic acid and aflatoxins. Cyclopiazonic acid appeared in 21 of 27 loose-shell kernel fractions at a range of 32 to 6,525 μg/kg and in 4 of 21 sound mature kernel fractions at a range of 32 to 130 μg/kg. Aflatoxins were detected in 26 of 27 loose-shell kernel fractions and in 20 of 21 sound mature kernel fractions. Cyclopiazonic acid used at 105 and 210 μg/kg to spike peanut samples was recovered at an average rate of 93.3%, with ranges of 89 to 119 and 166 to 221 μg/kg, respectively. The minimum detection limit on oxalic acid-impregnated silica gel plates was 26 ng.     

Clinical trial of chromium and yeast supplements on carbohydrate and lipid metabolism in diabetic men

Chromium (Cr) deficiency in experimental animals and in humans sustained by prolonged total parenteral nutrition has been shown to cause diabetes mellitus. Prior trials in humans indicated that Cr supplements, in either inorganic or organic form, may improve carbohydrate utilization. We report here a clinical double-blind, random cross-over trial of inorganic chromium trichloride, a brewer’s yeast that contained Cr as glucose-tolerance-factor (GTF), a brewer’s yeast extract without GTF, and a placebo. Forty-three outpatient diabetic men received three of these supplements for 4 months each. Subgroups included 21 ketosis-prone, 7 ketosis-resistant non-obese, and 15 ketosis-resistant obese men. Cr levels were followed pre- and post-treatment in hair, red blood cells, plasma, and urine. Response of carbohydrate metabolism to treatment was assessed in terms of change in insulin requirements, fasting plasma glucose, plasma cholesterol, and triglycerides, as well as the change in plasma glucose, glucagon, and insulin or C-peptide levels in response to a standard meal. In some men, these parameters were also measured after iv tolbutamide. Both the inorganic and organic oral Cr supplements increased measurable body pools of Cr in hair and red blood cells by about 25%. However, fasting plasma glucose and lipids and the glucose response to either the standard meal or to tolbutamide were not significantly altered by any of the treatments.     

Microfluorometric detection of asymmetry in the centromeric region of mouse chromosomes

A lateral asymmetry in the centromeric region of mouse chromosomes is revealed in studies involving the BUdR quenching of 33258 Hoechst fluorescence. This cytologically detected asymmetry may reflect the unequal distribution of thymidine between the two chains of mouse satellite DNA.     

Gonadotropin release as a function of mating and steroid feedback in the female rat

The aim of this investigation was to study possible relationships between mating-induced and steroid-induced luteinizing hormone (LH) release in spayed Long-Evans rats. Large amounts of LH were released approximately 7 hr following progesterone injection in rats primed with estradiol benzoate (EB). The amount of LH release varied widely depending on (1) the interval between the time of the progesterone injection and the EB priming; (2) the progesterone dose; and (3) the time of day when blood samples were collected. These findings provided confirmation of those of Caligaris, Astrada and Taleisnik (1971a). Females, prepared with estrogen-progesterone treatment in a variety of schedules in which the three above-mentioned variables were altered systematically, were allowed to mate with vigorous males. Mating under these various conditions did not significantly increase plasma LH levels even when the females showed high degrees of sexual receptivity. Sodium pentobarbital prevented the afternoon LH rise resulting from progesterone treatment 3 days after EB priming. Pituitary sensitivity to LRF was not enhanced in the afternoon and the mating did not significantly increase plasma LH in these barbiturate-blocked rats. Following administration of 5 large daily doses of EB without progesterone, however, significant increases in LH were produced by mating on the sixth day. Postcopulatory LH release in these circumstances was dependent on a diurnal factor since the effect of mating was greater in the afternoon than in the morning. Thus, although major LH release can be readily induced by mating in estrogen-treated spayed rats, this effect could not be obtained under conditions of progesterone administration to estrogen primed rats.     

Transport of O2 along a model pathway through the respiratory region of the lung

A pathway through the system of branching in the respiratory region of the lung is modelled by a circular cylinder, closed at one end, with partitions which define the component respiratory units. In this model the transport of O₂ during inspiration, generated by diffusion is compared with that produced by diffusion together with convection and the importance of convection in the respiratory region in promoting oxygen uptake at the alveolar wall is discussed. For this discussion it is only necessary to consider inspiration. The equations are solved numerically for flow rates of 10, 85 and 200 liters/min. O₂ uptake at the wall and curves of constant O₂ concentration are shown to illustrate the influence of convection. It is found that after a 2 sec inspiration from an O₂ tension of 98 mm Hg and a lung volume of 2300 ml, convection is about 12 per cent as important as diffusion at a flow rate of 85 liters/min, whereas at 10 liters/min convection is only about 0.4 per cent as important as diffusion.     

The effect of ultraviolet irradiation on soluble collagen

1. The effect of ultraviolet irradiation on acid-soluble and neutral-salt-soluble calf-skin collagen was studied by chromatography, gel filtration, amino acid analysis and sedimentation of the sub-units, and the reaction kinetics of degradation were obtained from viscosity and optical rotation measurements. 2. It was demonstrated that, whereas the structure of neutral-salt-soluble calf-skin collagen may be represented by the formula (alpha(1))(2)alpha(2), the acid-soluble extract has the formula alpha(1).(alpha(2))(2). The acid-soluble collagen is also unusual in containing a large amount of a component that could be beta(22). 3. Ultraviolet irradiation causes the progressive degradation of the collagen molecule into smaller molecular fragments that subsequently lose their helical nature. The rate constants show that the denaturation of soluble collagens by ultraviolet irradiation is much slower, under the conditions used, than denaturation by heat or enzymes.