• Korean Journal of Animal Reproduction
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• v.12 no.1
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• pp.48-50
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• 1988

Flehmen is well-known response which often occurs during the process of courtship in most mammals. Recent studies with domestic ruminants suggest that the flehmen may be involved in the mechanism of transferring some pheromonal substances to vomeronasal organ. Thus, variety of its significancehas been supposed, besides that male animals may use it for estrus detection. In this experiment, 8 male, 3 female and3 castrated goats of Saanen and its hybrid were used to ascertain whether urine from alien species can induce flehmen as that from same species. Urine was collected from twenty species consisting of 15 mammals, 3 birds and 2 reptiles and frozen until use. Mostly urine was sprayed to the nose of goats, but some coagulated ones were sniffed. Duration of flehmen was scored to four ranks as 0, 1-19, 20-39 and >40 sec. Each urine sample induced the response in any goats. However, much difference in the in tensity was found between the samples and according to the reproductive state of the receptor goats. Although individual difference was manifest, male goats generally showed more intense response than did female. Castrated goats showed the intermediate pattern. Administration of antiandrogen to the male goat tended to reduce the response. The results indicate that flehmen in the goat could occur for the urine of alien species as that of same species and the androgen may be one of the factors regulating the response.

• Journal of Veterinary Clinics
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• v.25 no.4
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• pp.310-313
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• 2008

C. perfringens is the most important enteric clostridial pathogen of animals. C. perfringens type A has been associated with hemorrhagic enteritis in a wide lange of domestic and wild mammals. But all types of C. perfringens can be normal inhabitants of the intestine of most mammals. We have a special case that showed C. perfringens type A infection in a hippopotamus (Hippopotamus amphibius) cub at Seoul Grand Park Zoo. Male, hippopotamus cub died in 3 days after birth. Clinical features of the hippopotamus cub have showed lethargy and anorexia before death. Gross post-mortem findings of the hippopotamus were hemorrhagic enteritis of intestine. Histopathologically, ruminant stomach and intestine showed hemorrhagic lesions and the lumen of the small intestine was filled with mucoid and hemorrhagic fluid. Also, intestine and stomach of hippopotamus were distended with gas and hemorrhagic fluid. C. perfringens was isolated in culture of small intestine and the presence of C. perfringens type A was confirmed by PCR. This case indicated that C. perfringens type A could be considered as a virulence factor responsible for causing death of a newborn hippopotamus.

• Journal of Korean Society of Forest Science
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• v.94 no.2 s.159
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• pp.112-116
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• 2005

This study was conducted to obtain the information of distribution, protection and management for mammal species in fragmented forest areas around the road from June 2002 to May 2003 in 9 study sites of Baekdugdaegan mountains, Korea. Field signs of twelve mammals, moles Molera robusta, Korean hares Lepus coreanus, Manchurian chipmunk Tamias sibiricus, red squirrels Sciurus vulgaris, Korean racoon dogs Nyctereutes procyonoides, Siberian weasels Mustela sibirica, badgers Meles meles, otters Lutra lutra, Bengal cats Felis bengalensis, wild boars Sus scrofa, water deer Hydropotes inermis and roe deer Capreolus pygargus were recorded in this study. There were no differences in total number of species between 50 m areas and 50-100 m areas from road in snow and non-snow season. Number of mammals' field signs were different in non-snow season between both areas. Red squirrels and Siberian weasels were more abundant in 50 m areas, and Korean hares and Manchurian chipmunks were in 50-100 m areas. Habitat using pattern of mammal species may be affected by the road. Reasonable road construction and maintenance would be needed for protection and management of wildlife and their habitats.

• Proceedings of the Korean Environmental Health Society Conference
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• 2002.04a
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• pp.69-73
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• 2002

There have been few reports on the survey of pathological findings of cetaceans stranded on the coast of Japan. This is partly because of lack of the procedures and/or network of systemic sampling of fresh tissues for the pathological study of stranded marine mammals. In contrast, there are a numbers of reports on the cause of illness and death in wild, free-living cetaceans examined in other countries; the commonest cause of death was parasitic and bacterial pneumonia except for entanglement in fishing gear. Anthracosis, lung and hilar lymph nodes polluted by suspended particulate matter in the air, has been recently found in some cetaceans stranded on the coast of Japan. In addition to the data from the chemical analysis of tissues, scientific data obtained from pathological study of stranded marine mammals would be also one of the useful base for the assessment of global environment. Usefulness of metallothionein in the hepatopancreas of crabs as a biomarker of marine pollution monitoring was also discussed in this study.

• Korean Journal of Animal Reproduction
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• v.18 no.3
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• pp.183-189
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• 1994

We examined early development in loach(Misgurnus mizolepis) embryos with parthenogenetic agents well-known in mammals. Female loach was superovulated with an intraperitoneal injection of 15 IU human chorionic gonadotrophin (hCG) per gram body weight. After 13 h of hCG injection, the oocytes were obtained from the abdomen. The oocytes were activated with 10% ethanol in tap water or fish Ringer's solution for 5, 10 and 15 minutes(eTW5, 10, 15 and eFRS5, 10, 15), respectively. The activation rates were 29% and 10% in eFRS10 and eFRS15, 5% and 6% in eTW10 and eTW15 by judging the cleaved blastomeres. Whereas, no parthenogenetic embryo was produced by tap water or fish Ringer's solution alone. The activation rate with the fish Ringer's solution was higher than that of tap water. No embryonic development was observed by calcium ionophore, A23187, at concentrations of 10, 20, 40 and 100$\mu$M when treated for 1, 2.5 and 5 minutes, respectively. The activation agents did not cause early development as in mammalian eggs. Therefore, the results suggest that fresh water fish may have a different egg activation pathway from that of mammals.

• Korean Journal of Environmental Biology
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• v.24 no.1 s.61
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• pp.1-6
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• 2006

Abstract - Global decline in wildlife mammals has been accelerated during past decades. Especially the conservation the wild life mammals in polar areas, is urgent. In an effort to understand the reproduction of the seals dwelling in the polar area, spermatogenesis in the seals was reviewed. Seals breed seasonally and in most of the seal species, delayed implantation is frequently observed. To date, histological and endocrinological evaluation revealed highly cyclic nature in supermatogenesis and steroidogenesis in testis. Seasonal changes in blood testosterone level together with melatonin is closely related with changes in light cycle between summer and winter. In adult testis at breeding seasons, spermatogenesis is manifested by consecutive 18 stages of germ cell development. Three kinds of Leydig cells different in steroidogenic activity as well as cellular morphology appear during the testis development. During non-breeding season, spermatogenic arrest and Leydig cell hypoplasia are frequently found. Interestingly, blood circulation through the anastomoses of pelvic veins cooled the testes and thus guarantees spermatogenesis within the body trunk. Endocrine disruptors and heavy metals have been found in the body tissues of several seals species and alter steroidogenesis in seals, suggesting environmental pollutants together with decrease in habitats are potentially threatening the reproductive success in seal species.

• Journal of Embryo Transfer
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• v.11 no.1
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• pp.71-80
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• 1996

The envelope of the rnannnalian oocyte plays crucial roles in sperm-oocyte interactions by providing sperm receptors, inducing acrosome reaction and preventing polyspermy. Understanding of properties of the zona pellucida (ZP) is essential for the artificial control of fertility in mammals. This study was carried out to produce and characterize monoclonal antibodies(MAbs) to porcine ZP proteins. Approximately 8,000 ZPs were obtained from follicular oocytes and dissolved in 40$\mu$l of double distilled water. Following immunization through foot-pad injections of Balb /c mice with a ZP solution, the popliteal lymph nodes were recovered at 2 weeks after the last injection. Hybridoma cell lines were established by fusing lymph node cells with P3X63 myeloma cells through selection using HAT medium and screening by immunofluorescence(IF) microscopy on the isolated ZP. Secreted MAbs were found to consist k chains and different heavy chains as evidenced by isotyping. Some of the MAbs demonstrated high specificity to the ZP in IF. The Mabs also showed positive cross reactivity with hamster and mouse eggs, while negative with bovine eggs. The results implicate that the MAbs can be used not only for identification of functional regions of the ZP, but also for elucidation of mechanisms involved in fertilization of mammals. The MAbs will provide basic information on biochemical anatomy of the ZP as well as can be candidates for the future contraceptive vaccines.

• Journal of The Korean Society of Clinical Toxicology
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• v.13 no.1
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• pp.40-42
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• 2015

Benzoylureas are chemical compounds best known for their use as insecticides. Diflubenzuron is one of the more commonly used benzoylurea pesticides. Others include chlorfluazuron, flufenoxuron, hexaflumuron, and triflumuron. They act as insect growth regulators by inhibiting synthesis of chitin in the body of the insect. They have low toxicity in mammals because mammals have no chitin. Chlorfluazuron insecticides, which are mixed with solvent naphatha, are commonly used. Thus we assume that in the presented case mental change outcome of poisoning was connected with toxic effects of solvent naphtha rather than with chlorfluazuron action. Components of solvent naphtha, particularly trimethylbenzenes, exert strong irritant action on the gastric mucosa and are very well absorbed from the gastrointestinal tract. We report on a 67-year-old man with stuporous mentality after intentional ingestion of approximately 200 ml of liquid chlorfluazuron in a suicide attempt. He was discharged after conservative treatments including gastric irrigation, charcoal, mechanical ventilation, hydration, and antibiotics for aspiration pneumonia without complications.

• Sleep Medicine and Psychophysiology
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• v.9 no.2
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• pp.81-85
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• 2002

There are several factors which are more likely to have sleep disorders in fertile women with menstruation than adult men. Menstrual cycle plays an important role in them. We describe herein the overview about the association of menstrual cycle and sleep disorders by viewing the interactions of menstrual cycle and circadian rhythm. We review how menstrual cycle affects sleep-wake cycle by reviewing menstrual cycle and estrous cycle to understand these interactions. Menstrual cycle and estrous cycle are mainly affected by hormonal cycle and light-dark cycle, respectively and they are generally determined in monthly rhythm and annual rhythm, respectively. The determination of estrous cycle is also affected by cyclic changes of hormones besides light-dark cycle. Although sleep-wake cycle almost alternates according to estrous cycle in non-primate mammals, it is hardly affected by menstrual cycle in primate mammals as compared with estrous cycle. But menstrual cycle affects sleep-wake cycle via desynchronization of sleep-wake cycle and temperature rhythm. The decrease of amplitude and phasic change during luteal phase in the daily fluctuation of body core temperature can partially contribute to the induction of sleep disorders in fertile women. In addition to this, premenstrual syndrome which nearly happens during luteal phase commonly have sleep problems. Therefore, we suggest that menstrual cycle and PMS can partially contribute the increase of sleep disorders in fertile women.

• Sleep Medicine and Psychophysiology
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• v.5 no.1
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• pp.1-11
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• 1998

Chronobiology is the area of medicine that is, how time-related event shape our daily biologic responses and apply to any aspect of medicine with regard to altering pathophysiology and treatment response. In mammals, there are several evidences that prove suprachiasmatic nuclei(SCN) is the major circadian pacemaker and the circadian rhythm influences so many biological aspects of an living organism such as rest-activity, thermoregulation, reproduction, and endocrine system. In case of human beings, there had been little information of circadian system. That may be due to the experimental, technical difficulties to study but also to the fact that human has the more complex environments that may alter the circadina rhythm like the artificial light, many socio-cultural aspects and so forth. However, several reports of these days indicate human's circadian system is composed of two or more circadian oscillators and SCN is the major circadian oscillator among them like the other mammals. Free-running circadinan period of mankind is about 24 hours rather than about 25 hours, and rest-activity rhythm is polymodal like other species. In addition to that, human may have capcities to change the circadian rhythm as the seasonal changes of daynight schedule. In this article, the author will summarize recent progress of anatomy and physiology of the circadian clock mechanism in humans.