• Korean Journal of Microbiology
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• v.21 no.2
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• pp.61-70
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• 1983

Synchronized cat kidney cells chronically infected with feline leukemia virus (FeLV) were used to study virus production, the synthesis of group specific antigen (gag) and envelope (env) proteins, the expression of env protein on the cell surface during the cell cycle, and the stability of viral RNA. As detecting method, we developed the radioimmunoassay (RIA) system using beta-emission of $^{131}I$ and demonstrated the validity of this system by comparison with routine RIA system using gamma-emission of $^{125}I$. The produced virus was analysed by developed RIA interval was determined by measuring reverse transcriptase activity. The results show that infected cells produce the complete virus particle containing products of gag, env and pol genes of FeLV, and maximum virus production occurs during mitosis of synchronized cells. Labeling of the cell surface of synchronized cells with $^{131}I$ shows that the amount of $gp70^{env}$ on the cell surface parallels cellular gorwth. Therefore, the cell cycle-dependent release of virus is not petition RIA of synchronized cells with $^{131}I$ labeled viral proteins synthesis during the cell cycle. The rate of synthesis of gag protein shows three peaks, corresponding to the $G_1,\;late\;S\;and\;late\;G_2$ phases of cell cycle. But the rate of synthesis of env protein dose not change, suggesting that in these cells the synthesis of these two gene products in controlled seperately. In Actionomycin D treated cells, the synthesis of viral proteins decreased sharply from 8 hours after treatment, and the late S and $G_2$ peaks of gag protein synthesis were disappeared. This shows the stability of viral RNA for about 6 hours in the absence of continuing viral RNA synthesis.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.119-123
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• 2007

The objectives of this study were to characterize the changes occurring in the levels of insulin-like growth factors (IGF-I and IGF-II) in bovine milk during a one-year lactation period, and to determine the parameters affecting IGF content in bovine milk. Milk was collected individually from lactating Holstein cows (n=70), and IGF-I and -II levels were determined via radioimmunoassay, using 125I after acid-ethanol treatment. The proximate compositions of the milk samples were determined using a near-infrared milk analyzer. The data were analyzed by the GLM and CORR procedures using SAS software to determine significant differences (p<0.05) occurring within groups (dairy farms, lactation periods, season, and parity). We noted an approximately six-fold reduction in the IGF-I concentration (from 2,462.7 to 353.0 ng/ml) and a three-fold drop in the IGF-II concentration (from 929.1 to 365.7 ng/ml) in the bovine colostrum, between 6 h after parturition and 18 h after parturition. IGF-I and -II content, measured at the early, middle, and late stages of lactation did not change significantly throughout the entirety of the lactation period. Interestingly, parity did not significantly affect IGF-I content, but did significantly affect IGF-II content between the primiparous and multiparous cows. We also found there were no significant relationships between IGF-I and total protein content or somatic cell counts (p<0.05).

• The Korean Journal of Nuclear Medicine
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• v.15 no.2
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• pp.67-74
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• 1981

The fasting serum gastrin levels were measured by radioimmunoassay in 32 normal healthy subjects without recognized gastrointestinal symptoms and 90 patients with various gastric diseases, who were visited or admitted to National Medical Center from February to June, 1981. The following results were obtained; 1) The fasting mean serum gastrin level in normal subjects was $55.9{\pm}26.3pg/ml$, and there was no difference between male and female. 2) The gastrin levels in gastric and duodenal ulcer were $85.0{\pm}28.4$ and $76.0{\pm}43.0pg/ml$ respectively, and it's values were elevated as compared with normal subjects. In gastric ulcer, the gastrin level was elevated than that of duodenal ulcer, but no significant difference in each other. 3) The gastrin level in stomach cancer was $89.5{\pm}42.2pg/ml$, and it's values were markedly elevated as compared with values in normal subjects. 4) The gastrin level in gastritis was $73.4{\pm}37.4pg/ml$, and it's values were elevated as compared with values in normal subjects. 5) The gastrin level in post-gastrectomy state was $50.3{\pm}16.3pg/ml$, and it's values were slightly decreased as compared with values in normal subjects.

• The Korean Journal of Nuclear Medicine Technology
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• v.22 no.1
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• pp.76-79
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• 2018

Purpose Carcinoembryonic antigen (CEA) is cell-surface 180-200 kDa glycoprotein that is overexpressed in breast, stomach pancreas, lung, and colorectal cancers. CEA was first described in 1965 by Gold and Freedman and then serum CEA of colorectal cancer patients was first measured in 1969 by radioimmunoassay by Thomson. CEA is currently most widely used tumor marker in the clinic for management of colorectal cancer. Various CEA test kits have been developed and commercialized. CEA kits from different manufacturers might have different test results because of different reagents and protocol. The purpose of this study was to compare results of four commercial available CEA kits. Materials and Methods This study was designed to evaluate four commercially available CEA kits using serum samples acquired from 120 patients who visited our clinic. Test results were compared and analyzed according to the respective test methods. High concentration samples were diluted with saline and diluted solution. Results All of the four kits showed a significant correlation within the reference value. However, three of the four kits used for the dilution test using high concentration samples showed the hook effect. Conclusion Results of the present study showed that It is important to establish the standardized dilution standards for the high-concentration specimens to manage the error of the test result by the hook effect.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.2
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• pp.264-271
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• 1998

A pilot study was undertaken to examine the possible health effects of electromagnetic fields(EMFs). The purpose of this study was to investigate of the EMFs exposures of personal environment, 60Hz magnetic fields. An experimental study was performed for six weeks of January-February 1998 to compare changes in melatonin levels in urine of 20 subjects during their normal sleeping hours and each 20 subjects in occupational and non-occupational group measured personal 24-h continual exposure, using EMDEX II (for 40-800Hz, Enertech Consultant, Inc.). An urine samples were collected 3 times a day(before sleep or around 24:00 ; immediately after wake-up ; around noon) for an week from each subjects and analyzed by radioimmunoassay. This study did not significant difference for the subjective average melatonin levels between occupational and nonoccupational groups exposed to electromagnetic fields. The mean personal exposure levels of occupational group were $0.215{\mu}T$, whereas non-occupational group were $0.18{\mu}T$. Occupational group were exposed more highly while at work. Finally, this study would provide significant data for furture study of exposure assessment of magnetic fields. A large scale study concerning more detailed exposure assessment should provide important information on health risk assessment of MFs. Further study should provide information on the contribution of various sources and the relationship between melatonin and immune system activity.

• Korean Journal of Veterinary Research
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• v.29 no.3
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• pp.253-262
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• 1989

This study was performed to investigate the patterns of progesterone secretion after induction of estrus in premature, metestrous and anestrous bitches. A total of 22 bitches were used. Of them 18 bitches were treated with hormone to induced estrus and 4 bitches were untreated and served as controls. Estrus was induced with $PGF_{2{\alpha}}$, estrone, estradiol-$17{\beta}$, PMSG and HCG(Treatment A), and with PMSG and HCG(Treatment B). Blood samples were collected via the cephalic vein at 2 to 5 days interval. Blood samples were centrifuged (1,200g, 10min.) within 30 minutes after collection and plasma was stored at $-20^{\circ}C$ until analyzed for the progesterone concentrations. Plamsa progesterone concentrations were measured by radioimmunoassay. The results of estrous induction were determined by estrous signs, ovarian response, egg recovery and progesterone patterns. The results obtained were as follows; 1. All bitches in treatment A showed estrous signs, however the ovarian response and egg recovery were not detectable and the levels of progesterone were nearly same as before. 2. In the treatment B, premature and metestrous bitches showed only estrous signs, however 5 of 7 anestrous bitches (71.4%) showed estrous signs, ovarian response and changes of progesterone levels. In conclusion, clinical estrous behavior can be induced during any phase of the estrous cycle, but ovulation should be induced only if induction occur approximately 4 months or more after the previous estrus.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1255-1262
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• 2014

Background: The aim of the study was to investigate any associations between benign prostate hyperplasia (BPH) and single nucleotide polymorphisms (SNPs) in the VDR gene (FokI, BsmI, ApaI and Taq${\alpha}$I loci) and the CYP17 gene (MspA1I locus), as well as TA repeat polymorphism in SRD5A2 gene among Lebanese men. Materials and Methods: DNA extracted from blood of 68 subjects with confirmed BPH and 79 age-matched controls was subjected to PCR/PCR-restriction fragment length polymorphism analysis. The odds ra=tio (OR) of having a genotype and the relative risk (RR) of developing BPH for having the genotype were calculated and the alleles were designated risk-bearing or protective. Results: Our data indicated that the A and B alleles of the VDR ApaI and BsmI SNPs were highly associated with increased risk of BPH (p=0.0168 and 0.0002, respectively). Moreover, 63% of the controls compared to 43% of the subjects with BPH were homozygous for none of the risk-bearing alleles (p=0.0123) whereas 60% of the controls and 28% of the subjects with BPH were homozygous for two or more protective alleles (p<0.0001). Conclusions: For the first time, our study demonstrated that ApaI and BsmI of the VDR gene are associated with risk of BPH among Lebanese men. Our study also indicated that overall polymorphism profile of all the genes involved in prostate physiology could be a better predictor of BPH risk.

• The Korean Journal of Nuclear Medicine
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• v.14 no.1
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• pp.37-44
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• 1980

The usefulness of single, random measurements of serum FSH and LH in the diagnosis of primary amenorrhea by radioimmunoassay was investigated. The 16 patients were divided into 3 groups by the level of serum FSH and LH. The first group with increased level of serum FSH and LH is five patients, all of these are related to the acquired or congenital abnormality of the ovary. Further studies indicated include buccal smear, chromosome analysis, gynecography and laparosocopy. The second group with normal serum FSH and LH is nine patients, four patients of these are related to the developmental anomaly of the Mullerian duct and five patients are undo etermined origin. Further studies indicated include laparoscopy and gynecography. The third group with decreased serum FSH and normal or decreased serum LH is two patients, one of these is related to the pituitary function, isolated FSH deficiency, the other is undetermined origin. Further studies indicated include the pituitary function test, LH-RH stimulation test, skull radiography. Determination of serum FSH and LH levels does not permit a specific etiologic diagnosis of primary amenorrhea. However the serum levels of FSH and LH can be used to differentiate the principal area of the investigation and can be of assistance in choosing more specific testing procedures.

• The Korean Journal of Nuclear Medicine
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• v.14 no.1
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• pp.45-56
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• 1980

$T_3-BSA\;and\;T_4-BSA$ conjugates were prepared and identified spectrophotometrically. The ${\lambda}max$ of the conjugates was just coincided with that of BSA, but the molar extinction coefficients of the conjugates were generally larger than that of BSA itself. The molar ratios of $T_3:\;BSA\;and\;T_4:\;BSA$ in the prepared conjugates were found to be 9:1 and 5:1, respectively. The titers of the $T_3$ antisera were generally higher (max. $1.5{\times}10^4:1$) than those of $T_3$ (max. $2{\times}10^3:1$), and the average cross reactivity of the $T_3$ antibody with $T_3$ was lower (0.45%) than that of $T_4$ antibody with $T_3(3{\sim}4%)$. The results of the study indicate that the predominant cause of the lower titers and the lower specificity of the $T_4$ antisera comparing with those of $T_3$ is mainly due to the unstability of the $T_4-BSA$ and consequent degradation of the conjugate to $T_3-BSA$ during preparation, purification, and even during immunization. The lower molar ratio of $T_4$ to BSA in the preparation stage is also considered to be a minor factor. By measuring $T_3,\;T_4$ levels in the reference control serum, it has been confirmed that the prepared antisera can sufficiently be utilized, respectively, in the established radioimmunoassay systems.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.9
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• pp.1286-1295
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• 2008

Leptin is produced by adipocytes and its role in the regulation of lipid metabolism, feed intake, productive and reproductive performance of domestic animal species has been greatly stressed and extensively investigated in recent years. This study was conducted to develop a radioimmunoassay (RIA) for the estimation of plasma bovine leptin and to determine plasma leptin concentration in fattening Japanese Black cattle (Wagyu) and its crossbreds at commercial farms. Relationships of plasma leptin with plasma vitamin A and age of crossbred cattle were also determined. Recombinant bovine leptin (rbleptin) was produced by the E. coli overexpressed leptin as a GST (glutathione S-transferase)-fusion protein. Then antiserum against bovine leptin was obtained by its immunization in rabbits. Using this antiserum, a bovine specific RIA was developed and plasma leptin level was determined in 120 crossbred fattening cattle (WagyuHolstein, 50:50) at commercial farms. The plasma leptin level increased with the age of cattle and its level was greater in the crossbred heifers than in the steers. Plasma vitamin A level was negatively correlated with plasma leptin level in crossbred heifers and steers. This relationship was stronger in heifers than in steers. Plasma leptin was gradually increased with advancing age in fattening Wagyu cattle. In conclusion, development of a bovine specific RIA to estimate plasma leptin will contribute to better understanding of the role of leptin in cattle.