• Proceedings of the Korean Society of Toxicology Conference
• /
• 1997.10a
• /
• pp.38-42
• /
• 1997

Human growth hormone is known as one of the peptide hormones which is consisted of 191 amino acids derived from the pituitary gland in humans. The objectives of this study were to supply inexpensive recombinant methionyl human growth hormones (rHGH) synthesized by the DNA technology in a yeast cell line and followed by the establishement of protein purification techniques. The next steps of the research were to study its physic-chemical properties and biological properties, and to evaluate various preclinical aspcts including pharmacokinetics sutdy, general pharmacology study, general toxicity test, and specific toxicity tests. Clinical phase I, II, III studies were also done against growth hormone dficient children to reveal that growth promoting effects were similar compared with the natural HGH extracted from pituitary glands and commercially available rHGHs. The results could be summarized that (I) this yeast dervied rHGH have had excellent physico-chemical and biological properties in comparison with a natural HGH and other synthesized rHGHs, (2) we could not see any toxic side effects when very high doses were administered to the experimental animals, and (3) this growth hormone showed effectiveness in the growth stimulating to growth hormone deficient patients.

• Biomolecules & Therapeutics
• /
• v.6 no.2
• /
• pp.171-181
• /
• 1998

DA-3585, a biosynthetic recombinant human erythropoietin has been developed as a treatment for anemia associated with chronic renal failure in Dong-A pharmaceutical Co. Ltd. This study was carried out to assess its acute and subacute toxicities in rabbits. DA-3585 was intravenously administered to rabbits at dose levels of 6250, 12500 or 25000 lU/kg for single dose toxicity study and at dose levels of 100, 500 or 2500 lU/kg/day for 4-week repeated dose toxicity study. In the acute toxicity study, dose up to 25000 lU/kg had no adverse effect on the behavior or body weight gain. Pathological examinations revealed no abnormal gross lesions related to DA-3585. In the subacute toxicity study, all animals survived until termination of treatment. DA-3585 had no influence on clinical signs, food and water intake or on body weight changes. Hematological examination showed increases in the number of RBC, hemoglobin contents and hematocrit values with a dose dependent manner in the animals treated with DA-3585. Histopathological examination revealed erythroid hyperplasia in the bone marrow and extramedullary hematopoiesis in the liver. The changes detected in the hematological and histopathological examination presumably represent exaggerated pharmacological effects of erythropoietin. The NOAEL (no-observed-adverse-effect-level) of DA-3585 was estimated to be 100 lU/kg/ day under this study condition.

• Biomolecules & Therapeutics
• /
• v.2 no.4
• /
• pp.376-382
• /
• 1994

Repeated injections of low-doses of mercuric chloride in rats or mice induce polyclonal activation which includes the induction of anti-glomerular basement membrane (GBM) antibodies and circulating immune complex and it results in nephritis. Because this disease is autoimmune mediated disease resulted from immune dysfunction, immunomodulators are used to control the symptoms or to cure the disease. Irpex lacteus Fr. is a kind of new medicinal fungus. The polysaccharide fraction extracted from submerged fermentation of Irpex lacteus Fr. decreased the serum agglutinin, serolysin and IgM plaque forming cells in normal mice. The hitherto obtained clinical results suggested that it significantly improved the oligourea, edema, and hypertension in patients who have nephritis. To elucidate the action-mechanisms of Irpex lacteus Fr., we established the experimental model of HgCl$_2$induced polyclonal activation by intraperitoneal administrations of HgCl$_2$to mice. To assess the immunomodulating effect of Irpex lacteus fraction, we Investigated its effects on the mitogen induced proliferation and IgM PFC counts of splenic lymphocytes in mice during the treatment of HgCl$_2$. The Irpex lacteus polysaccharide reduced the abnormally increased mitogen induced Iymphocyte proliferation and IgM PFCs to almost normal levels. And the Irpex lacteus polysaccharides prevented the increasement of serum immunoglobulin level induced by HgCl$_2$. These data suggested that the Irpex lacteus polysaccharides might have the immunomodulating activity to prevent and /or improve the HgCl$_2$ induced autoimmune disease.

• Biomolecules & Therapeutics
• /
• v.7 no.1
• /
• pp.14-21
• /
• 1999

The immunogenicity of the recombinant human basic fibroblast growth factor (rh-bFGF) was investigated by tests for active systemic anaphylaxis (ASA), passive cutaneous anaphylaxis (PCA), passive hemagglutination (PHA) and guinea pig maximization test (GPMT) in mice or guinea pigs. Guinea pigs were sensitized with rh-bFGF ($100-1000\;\mu\textrm{g}/kg$) or rh-bFGF-CFA mixture ($1000\;\mu\textrm{g}/kg$). All animals sensitized with rh-bFGF alone or mixture with CFA showed symptoms of anaphylactic shock. IgE antibodies to rh-bFGF were detected in sera obtained from rh-bFGF and rh-bFGF-Alum ($1000\;\mu\textrm{g}/kg$) sensitized mice, indicating that rh-bFGF has immunogenicity eliciting potential. IgG and/or IgM antibodies to rh-bFGF were also detected in all the sera obtained from sensitized mice by PHA. In the GPMT for delayed type skin reaction, no skin reaction was observed in sensitized guinea pigs after intradermal injection and dermal application of 0.01% rh- bFGF. However, these positive reactions were consistent with the results of another rh-bFGF, showing that rh- bFGF is a heterogenous protein to rodents. Considering the fact that rh-bFGF is a genuine human protein of which structure is identical to the endogenous human bFGF, it is thought that rh-bFGF is rarely associated with immunological problems in clinical use.

• Biomolecules & Therapeutics
• /
• v.11 no.4
• /
• pp.205-213
• /
• 2003

Various angiogenesis inhibitors target vascular endothelial cells and block tumor angiogenesis. Angiostatin is a specific endogenous angiogenesis inhibitor in clinical trials, which contains only the first four triple loop structures, known as kringle domains. Its generated by proteolytic cleavage of its parent molecule plasminogen, which itself does not exhibit antiangiogenic activity. Kringle domains from prothrombin, apolipoprotein, hepatocyte growth factor, urokinase and tissue-type plasminogen activator also elicit anti-angiogenic or antitumor activities in several model systems, albeit low amino acid sequence identity between angiostatin and each individual kringle. However, the differential effects of each kringle domain on endothelial cell proliferation, and migration observed in these kringle domains, suggest that the amino acid sequence of the primary structure is still important although kringle architecture is essential for anti-mlgiogenic activity. If it is further studied as to how amino acid sequence and kringle architecture contributes in anti-angiogenic activity, with studies on underlying mechanisms of anti-angiogenesis by kringle-based angiogenesis inhibitors, it will provide basis for the development of new potent anti-angiogenesis inhibitors and improvement of the efficacy of angiogenesis inhibitors.

• Biomolecules & Therapeutics
• /
• v.20 no.3
• /
• pp.326-331
• /
• 2012

We recently reported that Val-SN-38, a novel valine ester prodrug of SN-38, had greatly improved the intracellular accumulation of SN-38 in MCF-7 cell line, probably through enhanced uptake via amino acid transporters. In the present study, the efficacy of Val-SN-38 was further investigated both in vitro and in vivo. It was found that the in vitro cytotoxic effect of Val-SN-38 was similar to that of SN-38. Moreover, Val-SN-38 exhibited an equal potency to that of SN-38 in survival experiments in vivo. Because these results seemed to be contrary to the previous finding, further investigation was performed to find out the underlying cause of the contradiction. As only the lactone form is known to have cytotoxic activity, the proportion of lactone in Val-SN-38 and SN-38 was determined, but no differences were found. However, it turned out that Val-SN-38 had poor stability compared with SN-38, which resulted in a decrease in beneficial efficacy for Val-SN-38. Overall, the present study showed that a valine-added prodrug approach could be advantageous provided that the stability of the compound can be ensured. We believe this is a noteworthy study that unravels the discrepancy between intracellular accumulation and efficacy of valine-added prodrug.

• Biomolecules & Therapeutics
• /
• v.19 no.4
• /
• pp.472-476
• /
• 2011

Hypercholesterolemia indirectly increases the risk of arterial and venous thrombosis by enhancing the ability of platelets to aggregate. Yacon (Smallanthus sonchifolius) is composed of fructooligosaccharides, proteins, minerals and phenolic compounds, and has potential benefits for the management of diabetes. This study investigated whether the consumption of yacon in the diet inhibits platelet aggregation under hypercholesterolemic conditions. Male New Zealand white rabbits were fed one of five dietary interventions: a normal control diet, 0.5% cholesterol diet, 0.5% cholesterol diet+a low dose of yacon (0.5 g/kg body weight given orally each day), 0.5% cholesterol diet+a high dose of yacon (2.5 g/kg body weight given orally each day), or a 0.5% cholesterol diet+lovastatin (2 mg/kg body weight given orally each day). After 8 weeks, blood was collected to measure the amount of collagen- and thrombin-induced platelets present. Yacon inhibited the platelet aggregation induced by low doses of agonists (0.5 ${\mu}g/mL$ collagen and 0.02 units/ml thrombin) in a concentration-dependent manner. In addition, yacon concentration-dependently inhibited collagen-induced arachidonic acid liberation. Moreover, n-hexane, chloroform and ethyl acetate fractions showed a marked and selective inhibition of the platelet aggregation induced by collagen, again in a dose-dependent manner. These fractions, especially that of chloroform, significantly suppressed platelet aggregation. The results of this study demonstrate that when yacon is added to a cholesterol-enriched diet, cholesterol-induced platelet aggregation returns to control levels. This may also be beneficial in preventing atherosclerosis and reducing risk factors for coronary artery disease and stroke.

• Biomolecules & Therapeutics
• /
• v.23 no.4
• /
• pp.320-326
• /
• 2015

The clinical benefits of oncogenic BRAF inhibitor therapies are limited by the emergence of drug resistance. In this study, we investigated the role of a negative regulator of the MAPK pathway, Spry2, in acquired resistance using BRAF inhibitor-resistant derivatives of the BRAF-V600E melanoma (A375P/Mdr). Real-time RT-PCR analysis indicated that the expression of Spry2 was higher in A375P cells harboring the BRAF V600E mutation compared with wild-type BRAF-bearing cells (SK-MEL-2) that are resistant to BRAF inhibitors. This result suggests the ability of BRAF V600E to evade feedback suppression in cell lines with BRAF V600E mutations despite high Spry2 expression. Most interestingly, Spry2 exhibited strongly reduced expression in A375P/Mdr cells with acquired resistance to BRAF inhibitors. Furthermore, the overexpression of Spry2 partially restored sensitivity to the BRAF inhibitor PLX4720 in two BRAF inhibitor-resistant cells, indicating a positive role for Spry2 in the growth inhibition induced by BRAF inhibitors. On the other hand, long-term treatment with PLX4720 induced pERK reactivation following BRAF inhibition in A375P cells, indicating that negative feedback including Spry2 may be bypassed in BRAF mutant melanoma cells. In addition, the siRNA-mediated knockdown of Raf-1 attenuated the rebound activation of ERK stimulated by PLX4720 in A375P cells, strongly suggesting the positive role of Raf-1 kinase in ERK activation in response to BRAF inhibition. Taken together, these data suggest that RAF signaling may be released from negative feedback inhibition through interacting with Spry2, leading to ERK rebound and, consequently, the induction of acquired resistance to BRAF inhibitors.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
• /
• 1996.06a
• /
• pp.33-33
• /
• 1996

Interests in the field of rapid methods and automation in microbiology have been growing steadily on an international scale in recent years. International meetings concerned this problem have been held in elsewhere in the world countries since the past twenty years. But, unfortunately in the field of microbial examination in food hygiene, this problem have not yet been developed so much as in the field of clinical microbiology. Today, I would like to introduce you here present aspects of rapid and automation technologies, those which are manly carrying in milk and meats industries. My illustration will be given recent improved technologies using automatic apparatus and instruments along with process of microbial count procedure. Recent direct microbiological counting system (ChemeScan \ulcorner) as real time ultrasensitive analysis created by Cheminex Ltd., France is now most evolutional instrument to provide direct microbial counts, down to one cell, within 30 minutes. The results from these evaluations how a good correlation between the ChemScan system and the standard plate count method. This system will be successful application for not only in the field of pharmacology but also food microbiology. In addition, current identification of microbes by sophisticated instruments suitable for food microbiology, one of which Biology is manual system (BIOLOG\ulcorner), provides reference-level capability at a modes price. For the manual system, the color reactions in the microplate are read by eye and manually keyed into personal computer. Species identification appears on the computer screen within seconds, along with biotype patterns, a list of closely related species, and other useful statistics. In present this is useful application for microbial ecology and epidemiological survey. RiboPrinter system newly produced by DuPont is now focusing among microbiologists in the world, and is one of the biggest microbial characterization system using a DNA-based approach. The technology analyzer is bacterial culture for its genetic fingerprint or riboprint pattern. Finally Bio-cellTracer system for automatic measurement of fungal growth and Fukitori-Maseter, a Surface Hygiene Monitoring Kit by using swabe procedure in food processing environment are briefly illustrated in this presentation.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.12
• /
• pp.5251-5256
• /
• 2016

Background: Diagnostic karyotyping analysis is routinely used in acute myeloid leukemia (AML) clinics. Categorization of patients into risk stratified groups (favorable, intermediate and adverse) according to cytogenetic findings can serve as a valuable independent prognostic factor. Method and Material: A retrospective descriptive study was conducted based on the patient records of newly diagnosed non-M3 AML young adult cases undergoing standard 3+7 i.e, Daunorubicin and Ara-C (DA) as remission induction chemotherapy. Diagnostic cytogenetic analysis reports were analyzed to classify the patients into risk stratified groups according to South West Oncology Group criteria and prognostic significance was measured with reference to achievement of haematological remission after 1st induction chemotherapy. Results:A normal karyotype was commonly expressed, found in 47.2% of patients, while 65% (n=39) appeared to have intermediate risk cytogenetics, and 13.3% (n=8) adverse or unclassified findings. Favourable cytogenetics was least frequent in the patient cohort, accounting for only 8.3 % (n=5).The impact of cytogenetic risk groups on achievement of haematological remission was evaluated by applying Pearson Chi-square, and was found to be non-significant (df=12, p=0.256) but when the outcomes of favourable risk groups with intermediate, adverse and unclassified findings compared, results were highly significant (df=6, p=0.000) for each comparison. In patients of the favourable cytogenetic risk group, HR?? was reported in 40% (n=2/5), as compared to 62.2% (n=23/37) in the intermediate cytogenetic risk group, 57.1% (n=4/7) in the adverse cytogenetic risk group and 28.6% (n=2/7) in hte unclassified cytogenetic risk group. Conclusion: Cytogenetic risk stratification for AML cases following criteria provided by international guidelines did not produce conclusive results in our Pakistani patients. However, we cannot preclude an importance as the literature clearly supports the use of pretreatment karyotyping analysis as a significant predictive marker for clinical outcomes. The apparent differences between Pakistani and Western studies indicate an urgent need to develop risk stratification guidelines according to the specific cytogenetic makeup of South Asian populations.