• The Korean Journal of Applied Statistics
• /
• v.25 no.4
• /
• pp.633-640
• /
• 2012

Biological methods are described for the assay of certain substances and preparations whose potency cannot be adequately assured by chemical or physical analysis. The principle applied through these assays is of a comparison with a standard preparation to determine how much of the examined substance produces the same biological effects as a given quantity (the Unit) of the standard preparation. In these dilution assays, to estimate the relative potencies of the unknown preparations to the standard preparations, it is necessary to compare dose-response relationships of standard and unknown preparations. The dose-response relationship in the dilution assay is non-linear and sigmoid when a wide range of doses is applied. The parallel line model (applied to the dose region with the steepest slope) is used to estimate the relative potency. In this paper, the statistical theory in the parallel line model is explained with an application to a dilution assay data. The parallel line method is implemented in a SAS program and is available at the author's homepage(http://cafe.daum.net/go.analysis).

• Journal of the Korean Chemical Society
• /
• v.37 no.1
• /
• pp.68-75
• /
• 1993

Various biological activities (enzyme inhibitory potency, lipoxygenase inhibition, tadpole narcosis, vapor toxicity and heat of vaporization) of molecules are correlated with molecular descriptors. The molecular descriptors used in this works are molecular connectivity index, Wiener distance index and ad hoc descriptor, which can encode information about branching, size, cyclization, unsaturation, hetero atom content and polarizability. It is found that calculated values from multiple regression equations are in a good agreement with experimental data on five biological activities of alcohol, ester and ketone compounds.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.14
• /
• pp.5635-5641
• /
• 2015

Background: Cirrhosis is regarded as a possible end stage of many liver diseases, including viral infection. It occurs when healthy liver tissue becomes damaged and is replaced by scar tissue and finally may lead to hepatocellular carcinoma. Interferons (IFNs)are two general categories, type I and II. Type I includes one beta interferon and over 20 different alpha interferons. Alpha interferons are very similar in how they work, interacting with other proteins on cells like receptors. The main objective of this study was to compare Mx gene productivity post different cell line treatment with imported and Egyptian biosimilar locally produced IFNs, as well as the efficacy of those tested IFNs. Also, an assessment was made of sensitivity of different cell lines as alternatives to that recommended for evaluation of antiviral activity. Materials and Methods: Different cell lines (Vero, MDBK and Wish) were employed to evaluate cytotoxicity using the MTT assay. Antiviral activity was evaluated compared with standard IFN against VSV, Indiana strain -156, on tested rh-IFNs (imported; innovated and Egyptian biosimilar locally produced IFNs) in the pre-treated cell lines previously mentioned. The virus was propagated in the Wish cell line as recommended. Finally we estimated up-regulation of the Mx gene as a biomarker. Results: Data recorded revealed that test IFNs were safe in test cell lines. Viability was around 100%. Locally tested interferon did not realize the international potency limits, while the imported one was accepted compared with the standard IFN. These results were the same either using infectivity titer reduction assay or crystal violet staining of residual non- infected cells. Mx protein production was cell type related and confirmed by the detected Mx gene expressed in imported and locally produced IFN pre-treated cell lines. The expression of the gene was arranged in the order of Vero> wish > MDBK for the imported IFN, while for the Egyptian biosimillar locally produced one it was MDBK> Vero> wish. With regard to the antiviral activity there was a significant difference of imported IFN potency compared with the locally produced IFN (P<0.05), the IFN potential (antiviral activity) was not cell line related and showed non-significant difference for each separate product. Conclusions: Vero cells can be used as an alternative cell line for evaluation of IFN potency in case of unavailable USP recommended cell lines. Alternative potency evaluation assay could be used and proved significant difference in IFN potency in case of local and imported agents. Evaluation of antiviral activity could be used in parallel to viral infectivity reduction assay for better accuracy. Mx gene can be used as a marker for IFN potential.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2003.10b
• /
• pp.94-94
• /
• 2003

Tea is the most popular beverage in the world, especially green tea (Camellia sinensis) is daily taken by Asian people including Japanese. In last two decades, a variety of biological effects of tea components such as antioxidative, antimutagenic, anticarcinogenic, antibacterial and radical scavenging activities on bacteria, cultured cells and mammals have been elucidated.(omitted)

• YAKHAK HOEJI
• /
• v.45 no.2
• /
• pp.227-236
• /
• 2001

The complexity and variability of both the biologicals and the bioassays used to test them led to the use of the reference standard- a sample of the product of defined purity and potency, against which all preparations of that product must be calibrated. In order to prepare and establish KFDA reference standard for recombinant human growth hormone (somatropin), somatropin substance was filled in ampoules in National Institute for Biological Standards and Control (NIBSC). The candidate KFDA reference standard for somatropin (designated as 98/674) was evaluated to determine the suitability of serving as a KFDA reference standard for somatropin by the collaborative study, in which 10 laboratories participated. Physicochemical analysis and in vivo bioassay were performed by direct comparison with the international somatropin standard 88/624. 98/674 was identified as somatropin by SDS-PAGE, IEF, peptide mapping, and HPLC. Determination of somatropin content by SE-HPLC yielded a mean estimate of 2.01 mg somatropin per ampoule. Data from the study also yielded mean values of 0.39 $\pm$ 0.26% for high molecular weight impurities by SE-HPLC and mean values of 2.13 $\pm$ 1.29% for somatropin related proteins by RP-HPLC. Estimates of relative potency by weight gain bioassay in the hypophysectomised rats showed that relative potency of KS 98/674 was 1.07 aganist IS 88/624. Based on the results of the collaborative study, the candidate reference standard for somatropin is suitable to serve as a KFDA reference standard for somatropin.

• Proceedings of the PSK Conference
• /
• 2002.10a
• /
• pp.272.1-272.1
• /
• 2002

We have carried out collaborative study to evaluate a preparation of antithrombin concentrate whether or not it was suitable to serve as the candidate for a Korea National Biological Standard. Six laboratories. including three manufacturers and three National Control Laboratories. participated in this study. The potency of this candidate preparation was determined using the heparin cofactor chromogenic method. (omitted)

• Korean Journal of Environmental Agriculture
• /
• v.30 no.1
• /
• pp.82-88
• /
• 2011

BACKGROUND: Tetracyclines (TCs) are mainly regulated as parent compounds by bioactivity-based screening methods in food. Especially with respect to antimicrobial residues, their metabolites/epimers are also highly concerning chemicals and traditionally applied microbial detection methods are needed to improve with validation for regulatory control. METHODS AND RESULTS: Detection capability and biological activity of tetracycline (TC), chlortetracycline (CTC), oxytetracycline (OTC) and their epimers; anhydrotetracycline (ATC), epianhydrotetracycline (EATC), epitetracycline (ETC), 4-epi-chlortetracycline (ECTC), 4-epianydrochlotetra-cycline (EACTC), 4-epioxychlortetracycline (EOTC), were measured by microbial growth inhibition screening method of Korea Food Code. CONCLUSION(S): Limited detection capabilities were found, B. megarerium and B. subtilis showed for TC and CTC, and B. subtilis for OTC. Biological potency of each epimer was also presented against various microorganisms, at the level from 50% to 96%, comparing with parent TCs. It is recommended that more advanced microbial screening methods with validation are needed, and biologically active epimers are to be considered as marker residues for MRL setting of regulatory control purpose.

• Journal of the Korean Applied Science and Technology
• /
• v.19 no.4
• /
• pp.281-290
• /
• 2002

Dermorphin is a hepta peptide(H-Tyr-DAla-Phe-Gly-Tyr-Pro-Ser-$NH_{2}$)with exceptionally potent and long-lasting peripheral and central activity. Dermorphin analogues, dermorphionyl(DMP)-Lys-$NH_{2}$ and DMP-Lys-Lys-$NH_{2}$ have been prepared in order to examine the effect of opiod activity. Dermorphin analogues were synthesized by the solid phase method. The crude peptide was purified by gel filter on a Sephadex LH-20, characterized with HPLC and amino acid analyzer. Analgesic potency was estimated by writhing syndrome method and Randall-Selitto method. As a result, dermorphin analogues have lower potency than that of morphine.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 2003.11a
• /
• pp.117-117
• /
• 2003

PPARs (peroxisome proliferator activated receptors) are member of nuclear hormone receptors superfamily. Activations of PPARs upon binding with ligands modulate glucose metabolite, differentiation of adipocyte, inflammation response, and so on. Thiazolidinedione analog is one of potential antidiabetic drug that binds and activates PPARν selectively and enhances insulin sensitivity. In an effort to develop novel and effective antidiabetic thiazolidindione analogs, syntheses of benzoxazole and benzothiazole-linked thiazolidinedione analogs were performed via coupling reaction of benzoxazolylalkylaminoethanol with hydroxybenzylthiazolidinedione to develop novel and effective antidiabetic thiazolidindiones. All compounds were evaluated their biological potency by PPARν transactivation assay and revealed the similar potency with Troglitazone. However, lengthening of N-alkyl substituent did not seem to be beneficial for the activity.

• Molecules and Cells
• /
• v.27 no.5
• /
• pp.547-556
• /
• 2009

Parathyroid hormone is the most important endocrine regulator of calcium concentration. Its N-terminal fragment (1-34) has sufficient activity for biological function. Recently, site-directed mutagenesis studies demonstrated that substitutions at several positions within shorter analogues (1-14) can enhance the bioactivity to greater than that of PTH (1-34). However, designing the optimal sequence combination is not simple due to complex combinatorial problems. In this study, support vector machines were introduced to predict the biological activity of modified PTH (1-14) analogues using mono-substituted experimental data and to analyze the key physicochemical properties at each position that correlated with bioactivity. This systematic approach can reduce the time and effort needed to obtain desirable molecules by bench experiments and provide useful information in the design of simpler activating molecules.