Zum Proliferations-Stoffwechsel der Rattenleber nach Teilhepatektomie. Autoradiographische Untersuchungen mit3H-Cytidin,-Phenylalanin und -Thymidin

Summary During the first wave of parenchymal liver regeneration in adult rats after partial hepatectomy, the cellular synthesis and migration of RNA and the metabolism of protein were studied by autoradiography following an injection of³H-cytidine or³H-l-phenylalanine and double injections of 1 of these precursors +³H-thymidine. The following results were obtained: the synthesis and migration of RNA and the metabolism of protein are enhanced under these conditions of proliferation. In spite of this, the relation of metabolic activity in nucleolus, karyoplasm and cytoplasm remains constant. By double injection techniques it is proved that no differences exist in migration of RNA into the cytoplasm and cytoplasmic protein synthesis between cells with or without DNA synthesizing nuclei.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Sexual receptivity of the female and insemination power of the male Culex pipiens autogenicus (Diptera, Culicidae). The cases of strict monogamy and occasional polygamy]

Females of Culex pipiens autogenicus generally have two refractory periods: post-emergence refractory period (during the first 48 hrs. after emergence) and post-insemination refractory period. Males of Culex pipiens autogenicus can inseminate 2 to 3 females. After the 4th insemination he can no longer completely fulfill his reproductory role. Therefore the female can inseminated by another male.     

Macroscopic and microscopic study of human corpse skin grafting on athymic mice nu/nu]

32 thin grafts (500 to 700 mu) of different human corpse skin set apart during the first 24 hrs after the death have retaken on athymic Mousse whatever the reason of death and the age of the donor. 20 thick grafts have retaken at 30%. These skins preserve the aspects and behaviour of normal human skin but after 1 month they have a heavy melanic hyperpigmentation. These skins preserve their normal histological aspect during the first 3 days, then, when revascularisation is setting in, superficial areas of epidermic mortification, opposite dermal hypovascularised zones, appear. Between the 15th and the 21st day the epidermic alterations disappear and a heavy melanic hyperpigmentation is set up. The revascularisation is certainly the result of the human dermal vessels repermeabilisation. Till the 76th day neither dystrophy, dysplasia nor important inflammatory process exist.     

Norepinephrine in fetal and neonatal rabbit brain.

In the first hour after parturition, the newborn rabbit brain norepinephrine content is about 37% less than that of the fetus of 30th or 31st day. Later on, within 2 to 4 h, the norepinephrine level returns to the prenatal value and remains unchanged between 8 to 12 h. This transitory fall of the brain norepinephrine seems to be linked to the stress conditions which occur during parturition.     

Cellular control of the tick-borne virus antigen production in persistently infected cell culture

Summary The influence of inhibition or stimulation of cellular DNA synthesis on tick-borne virus antigen production in persistently infected cell culture was studied. Either mitomycin C or cytosine-arabinoside caused cessation of antigen-containing cell number increase. Stimulation of cellular DNA synthesis by growth medium change increased the level of antigen-containing cells. When HEp-2-Sof culture was synchronized, a correlation was observed between the entrance of cells into DNA synthesis phase and the increase of proportion of antigen-containing cells.     

Stimulation of the secretion of LH and FSH and increase in testicular weight at birth in rats]

The evolutions of serum LH and FSH concentrations and of testicular weight have been measured in the newborn Rat before, during and up to 24 hrs. after birth. A sudden and transient increase of LH and FSH is observed at birth. The testicular weight rises rapidly between 2 and 4 hrs.     

Increase in serum testosterone in newborn rats]

The changes in serum testosterone and dihydrotestosterone concentrations have been measured in the newborn Rat, before, during and up to 6 hrs after birth. A sudden and transient increase of serum testosterone has been found between 0 and 2 hrs. At 4 hrs, the value returns to that found in the foetus at the end of gestation.     

5-Bromodeoxyuridine inhibition of the transformation of Rous sarcoma virus-infected chicken cells]

The transformation of Rous-Sarcoma-Virus-infected synchronized Chicken cells is prevented when 5-bromodeoxyuridine is added for 3 hrs. at time of the peak of the first S phase following infection. Virus progeny is normally released. The inhibitory effect of BrdU is reversed by simultaneous addition of thymidine, but not by that of deoxyuridine. Hence, the inhibition of the transformation seems to result from the incorporation of the analogue into the nuclear DNA.     

酸解法对甘氨酸母液脱色后废活性炭的再生研究

在用海因法生产甘氨酸的过程中,为了精制甘氨酸,需要用大量的活性炭对甘氨酸母液进行脱色,而脱色后的活性炭就成了废活性炭.为了实现废活性炭的再利用,针对此废活性炭用酸解法对其进行再生.研究了再生酸种类、浓度、用量、再生温度和再生时间等对废活性炭再生效果的影响,确定了适宜的再生条件:硫酸质量分数为70％,硫酸溶液与废活性炭的...     

DNA synthesis in exocrine and endocrine pancreas after partial hepatectomy in Syrian golden hamsters

3H-thymidine autoradiography showed an enhanced DNA synthesis in acinar and islet cells of pancreas after partial hepatectomy in syrian golden hamsters. A significant nuclear labeling index of acinar cells was observed between 48 and 84 h and reached control levels by 120 h. An increased labeling index of islet cells was also observed, however, this increase was not statistically significant. These results indicate growth factor(s) produced after partial hepatectomy is capable of inducing DNA synthesis in pancreas.     

Combined action of nickel sulfate and x-irradiation on human lymphoblastoid leukemic cells]

In a first experiment, cells were cultured in media supplemented by nickel sulphate, irradiated in same media and cultured in same media after irradiation. In a second experiment, cells were cultured during 18 hrs. in media supplemented by nickel sulphate, and then cells were washed and cultured in normal media where they were irradiated. The nickel sulphate toxicity appears as a creasing function of the nickel sulphate concentration and the nickel sulphate action endurance. The nickel sulphate toxic effect is amplified by X-Rays. This amplification is a time function that depends on the X-Ray dose, nickel sulphate concentration and period of time from the outset of culture to the irradiation. The nickel sulphate toxic effect appears faster when nickel works after X-Rays.     

Comparison between serum LH and FSH levels in male and female rats during the perinatal period]

In the newborn female Rat, no transient LH and FSH serum surges were observed between 0 and 2 hrs., as compared with the newborn male. In the newborn female, a progressive increase in serum gonadotropins was observed between 2 and 6 hrs. These results indicate that, at birth, the pituitary-gonadal axis reacts in a different way in male and female Rats.     

In vivo continuous electrochemical determination of dopamine release in rat neostriatum]

Polarographic micro-electrodes (carbon fiber, o. d. 8 micron) implanted in the Rat caudate nucleus, allowed a practically continuous in vivo monitoring (one measurement every 5 sec.) of the extra-cellular concentration of dopamine released by striatal dopaminergic terminals. Administration of amphetamine produced a reproducible increase of the oxidation current. This effect was suppressed after the selective degeneration of the striatal dopaminergic terminals following the injection of 6-OHDA into the substantia nigra or after inhibition of the synthesis of the amine by alpha methyl-p-tyrosin. After 5 hrs. this drug produced a 70% decrease of the oxidation current.     

DNA synthesis in exocrine and endocrine pancreas after partial hepatectomy in Syrian golden hamsters

Summary ³H-thymidine autoradiography showed an enhanced DNA synthesis, in acinar and islet cells of pancreas after partial hepatectomy in syrian golden hamsters. A significant nuclear labeling index of acinar cells was observed between 48 and 84 h and reached control levels by 120 h. An increased labeling index of islet cells was also observed, however, this increase was not statistically significant. These results indicate growth factor(s) produced after partial hepatectomy is capable of inducing DNA synthesis in pancreas.This work is supported by NIH grant CA 36043.     

Evidence of a circadian sequence of photogonadsensitivity in the ferret]

Using "skeleton" photoperiods with a primary photofraction of 3 hrs. 30 min. and secondary photofraction of 30 min. located at various intervals after the onset of darkness, the occurrence of a photoinducible phase in the androgenic function has been evidenced in the Ferret. This photo-inducible phase seems to be located around 12 hrs. after the onset of the primary photofraction, since the ferrets who received the 30 min. photofraction 8 hrs. after the onset of darkness responded with a maximal increase in plasma testosterone.     

Differential sensitivity to ethidium bromide of replicative DNA synthesis and bleomycin-induced unscheduled DNA synthesis in permeable mouse sarcoma cells

Replicative DNA synthesis in permeable mouse sarcoma cells was more sensitive to ethidium bromide (EtBr) than bleomycin-induced unscheduled DNA synthesis (UDS). A similar difference in sensitivity to EtBr was observed between DNA polymerases alpha and beta. The difference in sensitivity to EtBr of replicative DNA synthesis and UDS in the present system seems to reflect mainly the sensitivity difference between DNA polymerases alpha and beta.     

Different sensitivities to ultraviolet rays of various functions of the polyoma virus. Stimulation of the synthesis of cellular DNA]

Peritoneal Mouse macrophage were used to study the stimulation of cell DNA synthesis by polyoma virus. Using ultraviolet-irradiated polyoma virus, it was possible to show a difference between the inactivations of infectivity and of induction of DNA synthesis. By statistically analysis of these two phenomena it was found that 39% of the viral genome is necessary for the induction of cell DNA synthesis.     

Cyercenes,novel pyrones from the ascoglossan molluscCyerce cristallina. Tissue distribution,biosynthesis and possible involvement in defense and regenerative processes

The extraordinary regenerative phenomena in the marine ascoglossan molluscCyerce cristallina are described here for the first time. The possible correlation between cyercenes, pyrones recently isolated from the mollusc regenerating dorsal appendages (cerata), and the processes of chemical defense and regeneration in the mollusc, was investigated by studying the tissue distribution, biological activity and biogenesis of cyercenes. Differences in distribution between theC. cristallina mantle, cerata and mucous secretion were found. Cyercenes showed activity in theHydra vulgaris regeneration assay and the mosquito fish ichthyotoxicity assay. The de novo biosynthesis of cyercenes from propionic acid was demonstrated by means of in vivo adsorption experiments with radiolabeled propionate.     

Preventive action of phenylalanine on acute intoxication of ochratoxin-A]

Ochratoxin-A, a mycotoxin causing kidney and liver damage, inhibits protein synthesis by competition with phenylalanine in the phenylalanyl-tRNA synthetase catalysed reaction. A dose of 0,8 mg ochratoxine per Mouse is 100% lethal within 24 hrs, when injected intraperitoneally. When phenylalanine is injected simultaneously with ochratoxine-A, the survival of the animals was 100% for 1 mg of phenylalanine per Mouse. Ten times higher doses of phenylalanine are necessary to obtain a 85% survival if the amino acid is injected 30 min. after the mycotoxin. Phenylalanine gives a very low protection if injected 1 hr or more ochratoxine-A.     

Protein anabolism in endometrium and myometrium during the growth of induced deciduoma in rats

Summary Protein anabolism in the endometrium and myometrium was studied during the growth of induced deciduoma in terms of incorporation of [¹⁴C]-leucine into proteins. The data show that the specific activity of the proteins was highest 2 days after decidualisation. Protein synthesis in the endometrium studied on that day as a function of time after injection of the labelled amino acid showed a steady increase during the first 2 h. Cycloheximide (2 mg/kg b.wt) administration produced nearly 95% inhibition of protein synthesis in endometrium as well as in myometrium.