Hypothalamic and hormonal control of photoperiodically induced vernal functions in the white-crowned sparrow, Zonotrichia leucophrys gambelii. 2. The effects of hypothalamic inplantation of testosterone propionate

The effects of implantation of testosterone propionate (TP) in various sites in the hypothalamus on the photoperiodically induced vernal premigratory functions in the White-crowned Sparrows were investigated in order to assess the role of the hypothalamo-hypophysial-testicular axis in the induction of these responses. Implantation of glass capillary tubes containing TP in the basal infundibular nucleus (IN), in the median eminence, or in the pars distalis inhibited the photoperiodically induced increase in plasma levels of luteinizing hormone (LH), as measured by radioimmunoassay, and testicular growth. The effective inplants significantly lowered the levels of LH in birds held on nonstimulatory short days. These TP implants apparently inhibited release from the pars distalis of both LH and follicle-stimulating hormone (FSH). It is concluded that the site of sensitivity in the negative feedback by testosterone is either the basal IN or the pars distalis, or both. The implants of TP that inhibited the increase in plasma LH and testicular growth completely did not prevent the birds from fattening.

Hypothalamic and hormonal control of the photoperiodically induced vernal functions in the white-crowned sparrow, Zonotrichia leucophrys gambelii. 1. The effects of hypothalamic lesions and exogenous hormones

To assess the role of the hypothalamo-hypophysial complex in the control of photoperiodically induced vernal premigratory responses in the White-crowned Sparrow, the effects of hypothalamic lesions and systemic administration of several hormones on these responses were investigated. Lesions that destroyed the posterior median eminence (PME) or the entire median eminence (ME) inhibited photoperiodically induced testicular growth, premigratory fattening and Zugunruhe. Lesions in the basal infundibular nucleus (IN) that resulted in complete inhibition of testicular growth abolished Zugunruhe, but allowed varying degrees of fattening. The systemic administration of prolactin, testosterone propionate (TP) or the combination thereof in the PME-lesioned birds induced fattening similar to that observed in photostimulated controls but did not induce Zugunruhe. It is concluded that testosterone and prolactin are the most important hormones involved in the control of vernal premigratory fattening. The role of these hormones in the induction of vernal Zugunruhe is not positively proven.

Purification and biological activities of pokeweek (Phytolacca americana) mitogens

Five mitogens, designated Pa-1 through Pa-5, were purified from the roots of pokeweed (Phytolacca americana) by means of ethanol fractionation, DEAE-cellulose column chromatography, affinity chromatography on a column of desialized human erythrocyte glycopeptide-Sepharose 4B, and gel filtration. Among these mitogens, only Pa-1 was mitogenic for both murine B-cells and T-cells, and the other mitogens were T-cell mitogens. Binding experiments with 125I-labeled Pa-1, a potent mitogen for B-cells, and with 125I-labeled Pa-2, the strongest T-cell mitogen, revealed that murine B-cells have more receptor sites for Pa-1 than for Pa-2 and murine T-cells have more receptor sites for Pa-2 than for Pa-1. The change of membrane fluidity within 30 min after binding of the mitogens to murine B- and T-cells was measured by fluorescence polarization of fluorescent hydrocarbon, 1,6-diphenyl-1,3,5-hexatriene, embedded in the membrane. Pa-1 induced increase of membrane fluidity of B-cells more markedly than Pa-2, whereas Pa-2 had a larger effect on the membrane fluidity of T-cells than Pa-1. Although both Pa-1 and Pa-2 stimulated the incorporation of 32 Pi into phosphatidylinositol of murine T-cells, neither Pa-1 nor bacterial lypopolysaccharide induced the activation of phospholipid metabolism of murine B-cells.

Identification of producer and biological activities of new antibiotics, mimosamycin and chlorocarcins

A strain of Streptomyces, No. 314 identified as a Streptomyces lavendulae produced under a novel condition of culture, four new antibiotics, mimosamycin and chlorocarcins A, B, and C. Among the components of chlorocarcin complex, chlorocarcin A was found to be most biologically active. This antibiotic inhibited the growth of Staphylococcus aureus FDA 209P and Corynebacterium diphtheriae at the concentrations of 0.1 and 0.003 mcg/ml, respectively. Chlorocarcin A also exhibited antitumor activity on EHRLICH carcinoma, ascitic and solid forms, and mouse leukemia L1210. Mimosamycin proved to be mainly active on Mycobacterium tuberculosis and inactive on the experimental murine tumors.

The fine structure of the hypothalamic secretory neurons of the white-crowned sparrow, Zonotrichia leucophrys gambelii (Passeriformes: Fringillidae). I. Parvocellular tuberal nuclei

The fine structure of the parvocellular tuberal nuclei and that of the ependyma bordering the third ventricle in the basal hypothalamus of the White-crowned Sparrow, Zonotrichia leucophrys gambelii, have been investigated. Photoperiodically stimulated birds have been compared with birds held on short days. The perikarya of the neurons of the basal infundibular (tuberal) nucleus, and in part, of the more dorsal layers, contain dense-cored granules (1000-1500 A). The granules in the anterior part of the nucleus are somewhat larger than those of the posterior part. The synapses and the synaptic relationships of these cells are described. The single-layered ependyma of the third ventricle in the basal hypothalamus may be divided into the dorsal typical ependyma, the ventrolateral "glandular" ependyma, and the ventral "glandular" ependyma. Cells of the ventral ependyma lack apical cilia but bear a few microvillous processes. They have well-developed Golgi apparatus, conspicuous polysomes, and frequently dense, irregularly-shaped granules. Basal cytoplasmic processes extend ventrally to the outer surface of the median eminence. Photoperiodic stimulation appears to increase the numbers of apical protrusions of the cells in the ventral glandular ependyma and to cause an increase in size of the nerve cells of the basal infundibular nucleus.

Preparation of perfluorodecalin emulsion, an approach to the red cells substitute

The major problems unsolved in fluorocarbon emulsions have been the long lasting retention of the substance in tissues of organs and acute shock symptom in animals receiving "coarse" emulsion with particles larger then 0.2 mum. This report offers a new, stable and sterile preparation of 25% "fine" perfluorodecalin emulsion with yolk phospholipid that is eliminated from liver, spleen and other organs within a few weeks, and whose acute and subacute toxicity is as low as perfluorotributylamine/Pluronic F68 emulsion. Effects of the perfluorodecalin emulsion thus prepared for maintaining contractile force of isolated guinea pig heart by perfusion and survival of animals receiving repeated circulatory exchange proved similar to perfluorotributylamine/Pluronic F68 emulsion.