CELL—CELL CONTACTS ACCELERATE CELL COLONY GROWTH IN SPARSE CULTURES OF CHICK EMBRYO FIBROBLASTS
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Abstract There is no cell proliferation in very sparcely plated chick embryo cell cultures. Substituting conditioned medium or adding of ethanol‐fixed homologous cells to the cultures accelerates cell colony growth. The mechanism for the mitogenic action of fixed cells is considered to be the contact stimulation of cell proliferation, and addition of extra cells to sparse culture is believed to mimic the cell micro‐environment existing in subconfluent cultures. The role of diverse cell—cell contacts in cultured cell growth regulation is discussed. The procedure used (addition of ethanol‐fixed cells) may improve normal cell cloning techniques.Keywords:
Cloning (programming)
The matured porcine oocytes were activated by ethanol stimulation and electrical stimulation.The results showed that the cleavage of electrical stimulation with two 1.6 kV/cm and 60 μs was higher(88.68%,94/106),and the cleavage rate of ethanol stimulation with 8% and 10 min was 84.21%(64/76).The method of electrical stimulation with two 1.6 kV/cm and 60 μs had higher cleavage rate,and laid the foundation for further study.
Parthenogenesis
Cleavage (geology)
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To obtain an in vitro method of LATS assay which is equally sensitive to a McKenzie bioassay, we compared the quality of cAMP generation-stimulation, thyroidal adenyl cyclase stimulation, and the stimulation of T3-release from mouse thyroid slices. Among those indicators of thyroid stimulation, stimulation by IgG of the release of T3 from incubated thyroid slices is the most sensitive, reproducible and reliable indicator, reflecting faithfully the results of a McKenzie bioassay. Stimulation of cAMP generation in slice manifested less sensitivity, but reasonable reproducibility. However, adenyl cyclase stimulation by IgG of patients with Graves' disease was erratic in two successive experiments, probably due to a non-specific effect of IgG. When adenyl cyclase stimulation was adopted as a sole indicator of thyroid stimulation, the results must be interpreted cautiously.
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Bivalent (engine)
Chiasma
Synaptonemal complex
Synapsis
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In the protocols of modern pharmacological studies of a self-stimulation reaction in rodents, stimulating electrodes are implanted as a rule unilaterally. The reinforcing properties of the left and right hypothalamus were suggested to be identical. The aim of the study was to clear up if the possibilities of the left and right hypothalamus to produce self-stimulation are similar or not. Methods. The study was carried out on adult male Wistar rats. The electrodes were implanted into the lateral hypothalamus bilaterally. The rats, in which an approach reaction was observed, learned self-stimulation in the Skinner box with stimulation of the left or right hypothalamus as a reinforcing agent descending thresholds of stimulation up to minimal one. Results. Self-stimulation of the left hypothalamus gave an approach reaction in the majority of rats (81.8%), self-stimulation reaction was developed in 72.7% of rats. Only 46.2% rats reacted on stimulation of the right hypothalamus, self-stimulation reaction was developed in 30.8% of rats. The thresholds of positive and negative reactions registered after electrical stimulation of both sides of hypothalamus were significantly differed (H(3, N = 31) = 14,92; p = 0,002). And these changes were not connected with lateralization but with sign of reaction: in general the thresholds of approach reaction were higher than thresholds of avoidance. Conclusion. In the paper, the fact of different possibility of approach reaction and self-stimulation development as a result of electrical stimulation of the left and right hypothalamus in rats has been described. After stimulation of the left hypothalamus, a possibility to receive positive reaction and to form self-stimulation on its basis is higher than after stimulation of the right hypothalamus. (For citation: Efimov NS, Bessolova YN, Karpova IV, et al. Asymmetry of reinforcing properties of the lateral hypothalamus in the self-stimulation test. Reviews on Clinical Pharmacology and Drug Therapy. 2018;16(2):37-41. doi: 10.17816/RCF16237-41).
Lateral hypothalamus
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Electrical brain stimulation
Tegmentum
Brain stimulation reward
Brain stimulation
Lateral hypothalamus
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Using the described experimental conditions whole anti-chick embryo hamster serum placed in proximity to the pre-incubated chick embryo stops the development of these embryos at a time which corresponds to the time the embryo antigen was obtained. Even though the experimental factors are complex the experimental series differed sharply from the controls. The anti-embryo serum also produced anomalies and a high mortality in the treated series. These experiments show clearly that chick embryos contain distinctive antigenic materials which are related to the embryo's age. The instep order of the results in the recipient embryos points strongly to the development of qualitatively different protein complexes in the embryo concurrent with the embryo's growth
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Taking distant hybrids of Lilium Asian,L.Longiflorum,L.Oriental and L.Trumpet as study materials,the embryo rescue experiments were conducted in different genotypes,embryo states and embryo ages.The results showed that: the obtaining rates of embryo-sacs and germination rate of embryos in different genotypes were obviously different.The germination rates of mature embryos were up to 85%.The germination rates of mature embryo-sacs were between 40%~60%.And germination rates of young embryo-sacs were low,most of them were below 20%.Among in vitro plantlets,the abnormal plantlets from mature embryos,mature embryo-sacs,and young embryo-sacs were also different.The optimal embryo age for embryo rescue of all genotypes was 35~90 days.Due to different genotypes,the obtaining rates of embryo-sacs or embryos had different changing patterns in different embryo ages.
Embryo rescue
Lilium
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Dose
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Ejaculation
Sexual stimulation
Lateral hypothalamus
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1. Adult mice of the Z(C3H) strain have been made tolerant of skin homo-grafts of the(A X Z) F1 hybrid strain by repeated intravenous and intraperitoneal injections of homologous spleen cells. 2. Repeated intraperitoneal injections of homologous spleen cells generally failed to induce a tolerant state, although 3/75 recipients accepted the homologous skin homotransplant.
Strain (injury)
Intraperitoneal injection
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