Discrimination of genetic sex in embryos of d-rR strain of the medaka (Oryzias latipes)

Zusammenfassung Die Körperfarbe des männlichen d-rR Medaka ist wegen des in Xanthophor enthaltenen Carotinoid-Pigments orange, die der weiblichen wegen seiner Abwesenheit uni. Die Färbung erfolgt im allgemeinen nach der Ausbrütung. Wird das rote Carotinoid des Paprikas unmittelbar nach der Befruchtung injiziert, so wird die dorsale Körperoberfläche des männlichen Embryos durch das Pigment gefärbt, was die Feststellung des erblichen Geschlechts schon vor der Ausbrütung erlaubt. Beurteilungsfehler konnten bis auf weniger als 10% herabgedrückt werden.     

The incorporation of45Ca into the egg of the Medaka,Oryzias latipes

Zusammenfassung Zur Markierung des intrazellulären Ca im Fisch-Ei wurde⁴⁵CaCl₂-enthaltende Ringer-Lösung in die Abdominalhöhle vonOryzias latipes injiziert. 2–3 Tage nach der Injektion zeigt die Radioaktivität der abgelegten Eier ihr Maximum und nimmt dann allmählich ab. Aus Mikroautoradiogrammen der abgelegten Eier geht hervor, dass⁴⁵Ca im Chorion und innerhalb des Eies eingebaut wird.     

Effects of the light-dark cycle and scheduled feeding on behavioral and reproductive rhythms of the cyprinodont fish, Medaka, Oryzias latipes

Medaka were maintained on a 16:8 light-dark cycle and fed once daily on one of 5 different feeding schedules. The daily rhythm of agonistic behavior rapidly entrained to the scheduled feeding time and maintained this entrainment during a 3-day starvation period. In contrast the daily rhythms of egg laying and courtship stayed entrained to the L:D cycle regardless of the feeding schedule. Thus, temporal integration of this fish with its daily environment can involve multistimuli which concurrently and differentially entrain externally expressed circadian systems.     

Effects of the light-dark cycle and scheduled feeding on behavioral and reproductive rhythms of the cyprinodont fish,Medaka,Oryzias latipes

Summary Medaka were maintained on a 168 light-dark cycle and fed once daily on one of 5 different feeding schedules. The daily rhythm of agonistic behavior rapidly entrained to the scheduled feeding time and maintained this entrainment during a 3-day starvation period. In contrast the daily rhythms of egg laying and courtship stayed entrained to the L:D cycle regardless of the feeding schedule. Thus, temporal integration of this fish with its daily environment can involve multistimuli which concurrently and differentially entrain externally expressed circadian systems.We thank Mark Goodrich and Steve Huber for fish maintenance and technical assistance; and Don Dovala for aid in developing the automatic feeder. The research was funded in part by NIH, AM 25191 and NIEHS, ES No. 01985.     

Inhibition of molybdenum blue formation by ATP

Summary Molybdenum blue formation was not affected by the presence of ATP up to a concentration of 1.2 mM/l. At higher concentrations the color development was inhibited relative to ATP concentration, finally reaching complete inhibition. Auto-hydrolysis of ATP was found at a rate of 1.4%/h. An exact determination of inorganic phosphate in the presence of easily hydrolyzed phosphate esters requires the measurement of extinction at fixed time intervals and extrapolation back to time zero.Acknowledgment. This work was supported by a grant of the Deutsche Forschungsgemeinschaft.     

Inhibition of prodigiosin formation inSerratia marcescens by adenosine triphosphate

Summary ATP, inorganic phosphate and ribose inhibited prodigiosin formation inSerratia marcescens, but adenine did not. ATP was not hydrolyzed by the organism during the experiment.     

The effect of castration,testosterone and estradiol on14C-serotonin metabolism by organ cultures of male rat pineal glands

Summary The pineal gland of the male rat does not appear to rely on prior conversion of testosterone to estradiol for the stimulant effect of testosterone on pineal melatonin and 5-methoxytryptophol synthesis.     

The effect of castration, testosterone and estradiol on 14C-serotonin metabolism by organ cultures of male rat pineal glands

The pineal gland of the male rat does not appear to rely on prior conversion of testosterone to estradiol for the stimulant effect of testosterone on pineal melatonin and 5-methoxytryptophol synthesis.     

Inhibition of Y-chromosome loop formation in primary spermatocyte nuclei ofDrosophila hydei by trimethylphosphate

Summary Primary spermatocyte nuclei of either late 3 instar larvae or newly eclosed adult males ofD. hydei contain lampbrush loops which are associated with Y-chromosome fertility factors. Formation of the loops is inhibited by continual larval development on food medium containing 0.008 M, or more, trimethylphosphate (TMP) and is accompanied by disruption to spermiogenesis.     

Inhibition of biological methylations by t,t-farnesylacetone, a constituant of the androgenic gland of the male crab, Carcinus maenas]

t, t-farnesylacetone 1 and hexahydrofarnesylacetone 2 have been previously identified in extracts from the androgenic gland of the male Crab Carcinus maenas. These compounds inhibit in vitro the methylation of E. coli B tRNA and of Calf thymus histones with S-adenosylmethionine methyl-14C as methyl donor and methylases from Crab testis. Rat liver or a 1-adenine methylase from a Mouse plasmocytoma (1 is approximately 200 times more active than 2).     

Inhibition of ultraviolet-induced hydroxyproline formation in human dermal collagen

Zusammenfassung In Gegenwart des Chelatbildners Dipyridyl ist die unter der Einwirkung von UV-Bestrahlung eintretende Oxydation von Prolin zu Hydroxyprolin gehemmt, wie hier am Beispiel von neutralsalzlöslichem dermalem Kollagen des Menschen gezeigt werden konnte. Die unter den gleichen Bedingungen einsetzende Degradation der primären Kollagenketten wird jedoch durch die Gegenwart von Dipyridyl nicht gestört, so dass ein direkter Zusammenhang zwischen den beiden Effekten ausgeschlossen werden kann.     

Inhibition of precipitin formation in the guinea-pig with cyclophosphamide

Zusammenfassung Cyclophosphamid (aber nicht 6-Mercaptopurin oder Vincaleukoblastin) verhindert die primäre Antikörperbildung beim Meerschweinchen. Auch bei fortgesetzter Stimulation mit dem spezifischen Antigen bleiben die Tiere relativ refraktär. Dieser Hemmeffekt wird weitgehend aufgehoben, wenn das Antigen mit Freund's Adjuvans injiziert wird.

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Aided by a grant from the American Cancer Society.     

Effects of progesterone and estradiol benzoate on superoxide dismutase activity in the brain of male rats

The activities of mitochondrial, manganese-containing superoxide dismutase (MnSOD) and cytoplasmic, copper-zinc-containing superoxide dismutase (CuZnSOD) were measured in subcellular fractions of whole brain homogenates prepared from intact and gonadectomized (GDX) male rats, untreated or treated subcutaneously (sc) with a single dose of 2 mg progesterone (P) and/or 5 g estradiol benzoate (EB). Neither MnSOD nor CuZnSOD was affected by the removal of the testes. Similarly, CuZnSOD activity was steady following systemic administration of P and/or EB to intact and GDX animals 2 h or 24 h prior to sacrifice. On the other hand, both P and EB suppressed MnSOD in the brain of either intact or GDX rats. These results suggest involvement of P and EB in the control of MnSOD activity in the brain of male rats.     

Inhibition of new blood vessel formation in mice by systemic administration of human rib cartilage extract

Summary 1 M HCl-guanidine extract of human funnel chest rib cartilage administered i.v. to mice decreased specifically vasoproliferation induced by intradermal injection of allogeneic murine lymphocytes.Acknowledgments. This work was supported by grant No. 10.5. from the Polish Academy of Sciences. We wish to acknowledge the valuable help of Dr A. Piasek in cartilage extract preparation.     

Inhibition of new blood vessel formation in mice by systemic administration of human rib cartilage extract

1 M HCl-guanidine extract of human funnel chest rib cartilage administered i.v. to mice decreased specifically vasoproliferation induced by intradermal injection of allogeneic murine lymphocytes.