• Development and Reproduction
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• v.4 no.2
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• pp.237-242
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• 2000

Growth hormone releasing hormone (GHRH), the major hypothalamic stimulus of GH secretion from the anterior pituitary gland, has been found to be present in several extrahypothalamic sites including placenta testis, ovary and anterior pituitary gland. The present study was performed to elucidate the role of pituitary GHRH on proliferation of cells derived from rat anterior pituitary gland. The GHRH content of pituitary tissue, cultured pituitary cells, and the conditioned media was evaluated by radioimmunoassay (RIA). Primary cultures of pituitary cells derived from adult rats were prepared by enzymatic dispersion. Significant amounts of GHRH-like molecules were detected in both pituitary tissue and cell cultures by GHRH RIA. Competition curves with increasing amounts of tissue extracts and conditioned media were parallel with those of standard peptide, indicating that the pituitary GHRH-like material is similar to authentic GHRH. To analyze specific cell types responsible for producing GHRH in anteroior pituitary, cell fractionation technique combined with GHRH RIA was performed. In cell fractionation experiment, the highest level of GHRH content was found in gonadotrope enriched-fraction and followed by somatotrope-, lactotrope- and thyrotrope-fraction. Treatment of pituitary cells with GHRH resulted in a dose-dependent increase in [$^3$H] thymidine incorporation. The mitogenic effect of GHRH could be mediated by typical oncogenic activation since the GHRH induced transient increase in c-fos mRNA levels with peak response at 30 minutes. The present study demonstrated that i) the pituitary GHRH expressed in the rat anterior pituitary gland can be secreted, ii) among the various cell types, gonadotropes and somatotorpes are the major GHRH source, and iii) the GHRH treatment increased the [$^3$H] thymidine incorporation and c-fos transcriptional activity in the pituitary cell culture. These findings suggested that GHRH could participated in the paracrine and/or autocrine regulation of cell proliferation, as well as promoting growth hormone secretion.

• The Korean Journal of Physiology
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• v.8 no.1
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• pp.27-30
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• 1974

It was planned to evaluate the influence of Panax Ginseng upon hepatic DNA synthesis in mice by observing incorporation of $[^3H]$ thymidine into the tissue cells. Thirty male mice$(body\;weight:\;18{\sim}20\;g)$ were divided equally into the ginseng and the saline groups. Each animal of the ginseng and the saline groups received every day (subcutaneously) 0.05 m1/10 g body weight of ginseng extract (4mg of ginseng alcohol extract in 1 ml of saline) and the same amount of saline, respectively, for 5 days. On the 5th experimental day, all animals received $1\;{\mu}Ci/g$ body weight of $[^3H]$ thymidine intraperitoneally 2 hours after the last medication. Five animals, at a lime, of each group were sacrificed 1, 10, and 24 hours after thymidine administration, and their hepatic radioactivity was measured autoradiographically in terms of the % number of radioactive cells in 1,000 cell counts (Radioactive Index, R.I.). Following results were obtained: 1. The hepatic radioactive indices obtained from the saline group 1, 10, and 24 hour after $[^3H]$ thymidine administration were $3.23{\pm}0.23,\;5.20{\pm}0.21,\;and\;6.00{\pm}0.30\;(mean{\pm}S.D.)$, respectively. 2. The corresponding values obtained from the ginseng group $(4.22{\pm}0.33,\;6.32{\pm}0.32,\;and\;7.42{\pm}0.35)$ were significant higher than the values of the saline group. The inference from the above results was that the ginseng facilitated hepatic DNA synthesis.

• Journal of Ginseng Research
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• v.19 no.2
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• pp.114-116
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• 1995

Panax ginseng ginsenosides were examined for their affects on the DNA synthesis. The DNA 1 synthesis was measured by the thymidine incorporation into NIH3T3 cells. The ginsenoside, panaxytriol, $Rh_1$ and $Rh_2$ showed reduced [$^{3}H$]-thymidine incorporation. However, other ginsenosides of $Rh_1$, $Rh_2$ and $Rh_3$ did not inhibit DNA synthesis. Among the various ginsenosides, ginsenoside $Rh_2$ was found to be the most inhibitory on DNA synthesis. We suggest $Rh_2$ as one of the potential choice of antiproliferative drugs.

• Journal of Pharmacopuncture
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• v.3 no.1
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• pp.1-19
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• 2000

To study anti-cancer effect and molecular biological mechanism of bee venom for aqua-acupuncture, the effects of bee venom on cell viability and apoptosis were analyzed using MTT assay, tryphan blue assay, $[^3H]$thymidine release assay, flow cytometric analysis, and activity of caspase-3 protease activity assay. To explore whether anti-cancer effects of bee venom are associated with the transcriptional control of gene expression, quantitative RT-PCR analysis of apoptosis-related genes was performed. The obtained results are summarized as follows: 1. The MTT assay demonstrated that cell viability was decreased by bee venom in a dose-dependant manner. 2. Significant induction of apoptosis was identified using tryphan blue assay, $[^3H]$thymidine release assay, and flow cytomet1 ric analysis of sub $G_1$ fraction. 3. In analysis of caspase-3 protease activity, the activity had increased significantly, in a dose-dependant manner. 4. Quantitative RT-PCR analysis of the apoptosis-related genes showed that Bcl-2 and Bcl-$X_L$ were down-regulated whereas Bax was up-regulated by bee venom treatment.

• Polymer(Korea)
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• v.28 no.6
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• pp.538-544
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• 2004

Polyurethanes containing L-lysine segments in the main chain (PULL) were synthesized from 4,4'-diphenymethyl diisocynate, poly(tetramethylene glycol), and z-lysine oligomer as a chain extender. Insulin-immobilized polyurethanes (PULL-In) were prepared by a coupling reaction of PULL surface amino groups with insulins. The amount of immobilized insulin was about 0.30 nmol/$\textrm{cm}^2$, as determined by Bradford method. The interactions of NIH/3T3 fibroblasts with surface-modified PULLs were investigated using $^3$H-thymidine incoporation and optical microscopy. The cell growth rate on PULL-In film was higher than those on other substrates. The cell proliferation by the immobilized insulin was almost same as that by the free one.

• The Journal of Korean Society of Virology
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• v.28 no.3
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• pp.215-224
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• 1998

Cloning, sequencing and expressing in E. coli of the thymidine kinase (TK) gene of Herpes simplex virus type-1 (HSV-1) strain F was investigated. The TK gene, located in the BamHI 3.74 kb DNA fragment of the plasmid pHLA-12, was amplified by polymerase chain reaction (PCR). The 1,131 kb PCR product was cloned into the BamHI and EcoRI sites of pBacPAK9 plasmid and then named pBac-TK recombinant. The TK gene was subcloned into the BamHI and BglII sites of pQE-30, and named pQE-TK recombinant. The nucleotide sequence of the 1,131 kb TK gene was determined, and the GC content was 65.13%. There were deduced 367 amino acid residues with a total molecular weight of 43 kDa. The weight was confirmed by the protein produced by E. coli M15/pQE-TK on the SDS-PAGE and Western blot. The production of the TK protein in the IPTG induced cells was measured over 4 h. At the end of 1, 2 and 3 h the level increased by 146, 204 and 242%, respectively. The amount of the protein at the highest fraction purified with Ni-NTA resin chromatography was $0.68\;{\mu}g$ per ml. The soluble state TK protein was present in the cytoplasm. In these results the F strain was different in base sequence and amino acid sequence from that of the CL101 strain, which caused difference in their strains.

• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.121-129
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• 1996

Multiplication of Herpes simplex virus type-1 was observed by electronmicroscopy, a gene library of the genome was constructed and thymidine kinase gene was cloned. Vero cells infected with the virus were lysed 48 h p.j. and multinucleated giant cells were observed approximately at 72 h p.i. The nucleocapsids were observed in nuclei and cytoplasm, and the assembled nucleocapsids were budded out through the vacuole and cytoplasmic membranes, and then virions were released from the cells. HSV-1 genome DNA was digested with BamHI and BglII enzymes and then the gene library of the genome fragments were constructed. The BamHI cleaved the genome DNA into twenty-seven fragments in the range of 1.1 - 14 kb, and BglII cleaved the genome DNA into sixteen fragments in the range of $4.5{\sim}20.1\;kb$. The pHLA-12 and pHLB-4 recombinant plasmids were contained TK gene by Southern blot analysis. The molecular sizes of the fragments which contained the TK gene were 3.74 in pHLA-12 and 6.41kb in pHLB-4 recombinant plasmid, respectively.

• Korean Journal of Food Science and Technology
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• v.5 no.3
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• pp.157-162
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• 1973

Mode of action study of irradiation was performed with potato tuber slices, $1mm{\times}1.5cm,$ aged on moist filter paper under aseptic technique. The time courses of invertase activity, nucleic acids and respiratory activity were determined, and sensitivities of these three processes to ionizing radiation were measured. None of those processes was severely inhibited by the dosage suppressing cell division. The result of $^3H-thymidine$ incorporation suggests that the reaction site of ionizing radiation might be existent during mitosis or $G_2$ period.

• Microbiology and Biotechnology Letters
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• v.20 no.3
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• pp.243-248
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• 1992

In order to examine the viability depending on rehydration process and membrane injury of Nocardia mediterranei upon lyophilization, We labeled $3^H$-thymidine in deoxyribonucleic acid of N. mediterrranei to obtain information on the mechanisms of injury caused by lyophilization. Suspensions of rehydrated cells were incubated with added DNase in a buffer solution. Extracellular radioactivity levels appeared to be high in the rehydrated solutions after lyophilization than freezing-thawing. Thus, the membrane systems were injured by lyophilization, but not ovenvhelmed. These considerations were confirmed by electron microscopy. In effects of rehydration, the cell membrane was seriously damaged by strong atmospheric pressure as soon as the inner ampule was opened, but this was not the case without admitting air under vacuum. N. rnediterranei cells, with no additives, were lyophilized and reconstituted without admitting air, virtually about 84% of the cells were viable.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.99-99
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• 2002

In the present study, the potent lipopolysaccharide (LPS)-mimetic stimulation of B cells and macrophages by hot water extract from Salicornia herbacea (S. europeae L.) is described. The extract activated spleen cells to proliferate in a dose-related manner as measured by [$^3$ H)-thymidine incorporation response.(omitted)