• YAKHAK HOEJI
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• v.38 no.2
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• pp.166-173
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• 1994

Sex hormones not only regulate external sexual characteristics but several internal biochemical processes. It is well accepted that life-span of female is longer than that of male. Life-span is closely related with aging process in which free radicals are known to be involved. We investigated the effect of testosterone on free radical generating systems and lipid peroxidation based on the sexual difference. Lipid peroxide levels of male and female mouse were increased proportionately with age, especially in male mouse. Increase in enzyme activity of aldehyde oxidase with age was observed in male mouse, while no siginificant change in enzyme activity was found in female mouse. Enzyme activity of xanthine oxidase also showed similar results. It, however, was not significant statistically. Lipid peroxide level and xanthine oxidase type conversion ratio of male and female mouse liver homogenate incubated at $37^{\circ}C$, increased remarkably in proportion to incubation time, especially in male mouse. Lipid peroxide level and aldehyde oxidase activity were measured in normal male mouse, castrated mouse and testosterone treated-castrated mouse. Castrated mouse group showed decrease in lipid peroxide level and aldehyde oxidase activity compared with normal group. Treatment of castrated mouse with testosterone, however turned the level of lipid peroxide and aldehyde oxidase activity back to normal. From the above results, it might be concluded that testosteron could increase the activities of free radical generating enzymes which would result in the formation of lipid peroxide, consequently leading to aging.

• Toxicological Research
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• v.20 no.3
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• pp.273-280
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• 2004

The present study was carried out to investigate the potential toxicity of dimethyl disulfide by a 2-week inhalation in F344 rats. The test article, dimethyl disulfide, was exposed by inhalation to male and female rats at dose levels of 0, 33, 100, or 300 ppm/6 hrs/day for 2 weeks. At the end of treatment period, all males and females were sacrificed. During the test period, clinical signs, mortality, body weights, food consumption, hematology, serum biochemistry, and gross findings were examined. The mean body weights of the male 300 ppm group and the female 33 ppm or higher dose groups were significantly lower than those of the control group, respectively. The mean food consumption at male 300 ppm and female 100 and 300 ppm were significantly decreased compared with the controls. Some treatment-related serum biochemical changes, including decreased alkaline phosphatase at male 300 ppm and female 100 and 300 ppm, reduced total bilirubin at male 300 ppm, and decreased alanine aminotransferase at female 300 ppm, were observed in a dose-dependent manner, but these findings were considered to be of no toxicological significance. There were no adverse effects on mortality, clinical signs, hematology, and necropsy findings in any treatment group. Based on these results, it was concluded that the 2-week repeated dose of dimethyl disulfide by inhalation resulted in suppressed body weight gain and decreased food consumption at the dose of male 300 ppm and suppressed or reduced body weight gain and decreased food consumption at the dose of female 33 ppm or higher. In the present experimental conditions, the no-observed-adverse-effect level (NOAEL) was considered to be 100 ppm/6 hrs/day for male rats and below 33 ppm/6 hrs/day for female rats.

• Toxicological Research
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• v.20 no.2
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• pp.131-136
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• 2004

3-Monochloro-1,2-propanediol(3-MCPD) is a toxic compound, often present in different foods containing acid hydrolyzed(AH) protein, like seasonings and savory food products. The purpose of the present study was to investigate the effects of 3-MCPD on male fertility, sperm and testosterone secretion. In vivo male fertility test was performed for observing the adverse effects of 3-MCPD on the function of male reproductive system and pregnancy outcome. 0.01, 0.05, 0.25, 1 and 5 mg/kg b.w. of 3-MCPD was given daily by gavage to groups of 15 adult male SD rats for 4 weeks. At the end of pre-treatment period, males were mated overnight with normal females. Following morning, males demonstrating successful induction of pregnancy were sacrificed on that day to assess sperm parameters and histopathology of reproductive organs. The resulting pregnant females were sacrificed on day 20 of gestation to evaluate pregnancy outcome. As a result, four-week paternal administration with 3-MCPD resulted in adverse effects on male fertility and pregnancy outcome without remarkable histopathological changes in testes and epididymides; sperm motility, copulation index and fertility index were markedly decreased in the treated group and numbers of live fetuses showed steep dose-response curves. Also, spermatogenesis was investigated in this experiment. However, no effect was observed on production of sperm in testes treated with 3-MCPD for 4 weeks. Hormone assay was performed for observing the effects of 3-MCPD on testosterone and luteinizing hormone (LH) in blood and testes of male SD rats and cultured primary Leydig cell. In result, significant changes of related hormones did not observed by treatment of 3-MCPD. These results indicated that paternal treatment with 3-MCPD induced spermatotoxic effect, which caused an antifertility on male.

• The Journal of Korean Academic Society of Nursing Education
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• v.22 no.3
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• pp.334-344
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• 2016

Purpose: The study was conducted to investigate the effect of career barrier, satisfaction, and career decision making pattern on career search behaviors in male nursing students. Methods: Data were collected through structured questionnaires that included general characteristics, career barrier, satisfaction, career decision making pattern and career search behaviors and were analyzed by descriptive statistics, ANOVA, t-test, Pearson correlation coefficient and multiple regression using SPSS/PC+ program. Results: The results of the research suggest the two aspects of career search behaviors as being self-exploration and environmental exploration. The rational pattern, among the types of satisfaction and career decision making pattern, was found to have a meaningful effect on self-expression. On the other hand, dependent pattern, among the satisfaction and career decision making pattern, was found to have an effect on career search patterns. Conclusion: It is considered that, based on the results of this study, diversified approaches that consider individual career decision making patterns such as rational pattern and dependent pattern as well as the methods to enhance the satisfaction of male nursing college students for career guidance are needed.

• The Journal of Korean Physical Therapy
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• v.19 no.3
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• pp.11-17
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• 2007

Purpose: The purpose of this study were to analyze fatigue patterns of the rectus femoris muscle by isometric contraction. Methods: Twenty healthy subjects(10 male, 10 female) participated in this study. Maximal voluntary isometric contraction(MVIC) was measured by the dynamometer. Muscle activity was recorded from the rectus femoris muscle. During the experiment, the subject was seated in the chair. The measured items, median frequency(MDF) and root mean square (RMS), were collected from the surface EMG. All data were analyzed using repeated measures ANOVA. Results: There was significant difference of MVIC between male and female. Endurance time was significant difference by the level of MVIC but no significant in the main effect(sex) and interaction effect. The MDF and fatigue index were significant differences in the interaction effect. The RMS was not significant difference in both of main and interaction effect. The muscle fatigue patterns of female was greater than male after 60% MVIC. Conclusion: This study showed that sex differences of muscle fatigue were started from 60% MVIC.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.123-126
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• 2002

More than three hundred million men in the world are suffering from erectile dysfunction. Korean ancient medical records say that the unmated male silkworm moth is effective in strengthening men's vitality, but no scientific examination has preyed its clinical efficacy. Currently, silkworm moths are not allowed for food-stuff. Thus, we selected silkworm of 14-days-after-metamorphosis, at which external morphology possesses that of pupae, but internal component is that of moths. To obtain the reliable source of unmated male silkworm moth, we used the sex-limited silkworm breed with larval marking. The body marker allows casual separation of sex during larval period, preventing mating right after emergence from cocoon. Using the extract prepared with the pupae of 14-days-after-metamorphosis, we investigated the tonic effect of the extract on the rat fed the extract for three weeks. The results showed that the testosterone levels in serum increased maximum by 19%, that of testicle increased maximum by 200%, and athletic endurance of the rats rose by 6%, suggesting positive tonic effect of the pupae prepared at the stage of 14 days after metamorphosis.

• Journal of Sericultural and Entomological Science
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• v.34 no.1
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• pp.21-29
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• 1992

In the experiment, gene actions were analyzed for seven silkworm varieties in order to obtain basic information on their genetic improvement by diallel crosses. The results obtained were summarized as follows : in analysis of variance, significantly maternal and reciprocal effects were observed for all character except female cocoon shell percentage and female pupal weight. Over-dominance was shown by Vr-Wr graphic analysis in three characters such as female cocoon weight, female and male pupal weight, and partial dominance in five characters such as male cocoon weight, cocoon shell percentage in both female and male. Component of genetic varience analyzed for five characters such as male cocoon weight, cocoon shell weight, cocoon shell percentage in both female and male showed that additive effects were higher than dominant effects, and female cocoon weight showed dominant effects higher than additive effects. Heritability of narrow sence was higher more than 0.51 and heritability of broad sence was higher more than 0.77 in all characters except for female pupal weight. The directions of dominance were negative for female cocoon shell weight and somewhat higher for female and male cocoon shell percentage. Meanwhile cocoon weight, pupal weight in both female and male showed positive in the direction of dominance.

• Korean Journal of Animal Reproduction
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• v.4 no.1
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• pp.47-74
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• 1980

The present experiments were carried out to elucidate the effects of hypophysectomy and subsequent administration of sex hormone on thyroid, adrenal gland, gonads and blood plasma components in the rat. The jresults obtained were summarized as follows: The weight of the thyroid gland of both male and female hypophysectiomzed rats decreased markedly from 7 days up to 56 days after the hypophysectomy as compared to the control group. The administration of sex hormone (6 mg of testosterone propionate to male and 6 mg of hexestrol to female) to the hypophysectomized rat gave on effect on the change in the weight of the thyroid gland. The hopophysectomy decreased the uptake of radioactive iodine in the thyroid gland in both male and female rats with time. Subsequent administration of the sex hormone caused no effect. With regard to the histological changes of the thyroid gland, the hypophysectomy caused significant changes in the gland showing a remarkable degeneration. The function of the gland seemed to disa, pp.ar almost completely on 56th day after the hypophysectomy. Upon the administration of sex hormone after the hypophysectomy, however. the epithelia of the follicle which has changed to flat from has partly returned to its functional cubicfrom and nuclei recovered as nearly as normal. These recovery were more remarkable in the female than in the male. The hypophysectomy kept causing a significant decrease in the weight of the adrenal gland in male and female rats during the period of observation (up to 56 days) as in the case of thyroid gland. The administration of sex hormone has on effect in this respect either. The hypophysectomy also caused a marked morphological change in the gland: zona fasciculata and zona reticularis were dicreased in size quichly after the hypophysectomy. The administraton of the sex hormone to the hypophysectomized rat resulted in clear distinction among the three layers of the adrenal cortex which otherwise very diffused. In the male, this phenomenum was more remarkable than in the female and the pattern of the cell arrangements and the thickening of each layer became similar to those of normal rats. The gonads of both sexes have also kept decreasing in the weight and degenerated in morpohology after the hypophysectomy. However, the degenerate follicle became enlarged after the administration of hexestrol in the female. Furthermore, the vacuoles found in interstitial cells of hypophysectomized rat disa, pp.ared after the administration of testosterone in the male and the formation of spermatocytes seemed to be recovered. Hypophysectomy also caused a gradual increase in the contents of total protein, non-protein nitrogen, total lipid, cholesterol and calcium in the blood plasma with time. The concentrations of sodium, potassium and chloride in the blood did not change after the hypophysectomy. Sex hormone caused practically no change in above tendency.

• The Journal of Korean Medicine
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• v.20 no.1 s.37
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• pp.22-29
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• 1999

To evaluate the effect of Choakwiyeum water extract on the male reproductive functions, experiments were performed on male rats. The results obtained were as follows: 1. Intromission frequency was increased significantly after the administration of Choakwiyeum water extract in male rats. 2. Intromission latency was increased significantly after the administration of Choakwiyeum water extract and ketoconazole in male rats. 3. Mount frequency was increased significantly after the administration of Cboakwiyeum water extract and TCDD in male rats. 4. Serum testosterone concentration was increased significantly after the administration of Choakwiyeum water extract in male rats. 5. Serum testosterone concentration was increased significantly after the administration of Choakwiyeum water extract and ketoconazole in male rats.

• Journal of Environmental Health Sciences
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• v.33 no.3
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• pp.207-210
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• 2007

The study was designed to determine the estrogenic effect of some penicillins on endocrine function in adult Japanese medaka (Oryzias latipes). Vitellogenin (Vtg) produced in male fish has been used for a biomarker to study endocrine disrupters. $17\beta-estradiol\;(E_2)$ was used a positive control that was induced Vtg in male fish. Result of total protein qantification and ELISA for female and male fish were exposed to $17\beta-estradiol$ 10ng/ml for $3\sim5$ days. As a result, male fish exposed to amoxicillin respectively appeared 0.75, 0.23, 8.21 and $9.36\%_{\circ}$ of 1, 10, 100 and 1000 ppm respectively, that value was elevated compared with control male fish. Male fish exposed to ampicillin respectively appeared 1.85, 4.68, 0.85 and $39.59\%_{\circ}$ of 1, 10, 100 and 1000 ppm respectively, that value was elevated compared with control male fish. This study is one of the first reports suggesting potential endocrine disruption of some penicillins in aquatic ecosystem. These results suggest that vitellogenin and estrogen receptor induction patterns alter in male medaka treated with selected estrogenic compounds, and that these results may be useful molecular biomarkers for screening estrogenic EDCs (endocrine-disrupting chemicals) in the shortest possible time.