• Title/Summary/Keyword: reproductive role

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A Role of Plasminogen Activators in Animal Reproductive Cells and Organs

  • HwangBo, Yong;Cheong, Hee-Tae;Yang, Boo-Keun;Park, Choon-Keun
    • Reproductive and Developmental Biology
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    • v.38 no.2
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    • pp.63-70
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    • 2014
  • Plasminogen activators (PAs) are serine proteases that convert plasminogen to plasmin. Two type of PAs are urokinase-type PA (uPA) and tissue-type PA (tPA). Plasminogen is present in most extracellular fluids. PAs play in various reproductive processes including implantation, ovulation and fertilization. In the spermatozoa, PAs and PAIs play a role in sperm motility and fertilization. PAs in the sertoli cell are stimulated spermatozoa maturation and sperm activation through the phospholipase A2. The oocyte maturation is the process for fertilization and implantation. PAs in cumulus-oocyte complexes (COCs) are related to oocyte maturation by protein kinase A and C. In the ovulatory process, PAs activity are changed and it are related to reducing the tensile strength of ovarian follicle wall. The uterine environment is important for reproduction and the uterus undergo tissue remodeling. In the uterus and oviduct of mammals, expression and activity of PAs are changed during estrous cycle. Thus, expression and activity of PAs are concerned to many reproductive functions. Therefore, PAs seem to important factor of regulator in reproductive events.

Malignant Tumors of the Female Reproductive System

  • Weiderpass, Elisabete;Labreche, France
    • Safety and Health at Work
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    • v.3 no.3
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    • pp.166-180
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    • 2012
  • This review summarizes the epidemiology of cancer of the female reproductive system and associated lifestyle factors. It also assesses the available evidence for occupational factors associated with these cancers. Cervical, endometrial, and ovarian cancers are relatively common, and cause significant cancer morbidity and mortality worldwide, whereas vulvar, vaginal, fallopian tube cancers, and choriocarcinomas are very rare. As several lifestyle factors are known to play a major role in the etiology of these cancers, very few published studies have investigated possible relationships with occupational factors. Some occupational exposures have been associated with increased risks of these cancers, but apart from the available evidence on the relationships between asbestos fibers and ovarian cancer, and tetrachloroethylene and cervical cancer, the data is rather scarce. Given the multifactorial nature of cancers of the female reproductive system, it is of the utmost importance to conduct occupational studies that will gather detailed data on potential individual confounding factors, in particular reproductive history and other factors that influence the body's hormonal environment, together with information on socio-economic status and lifestyle factors, including physical activity from multiple sources. Studies on the mechanisms of carcinogenesis in the female reproductive organs are also needed in order to elucidate the possible role of chemical exposures in the development of these cancers.

Sexual Dimorphism on the Shell of Littorina brevicula (Philippi) (Gastropoda: Littorinidae)

  • SON Min Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.6
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    • pp.992-996
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    • 1997
  • Study on sexual dimorphism in Littorphism in Littorina brevicula should be interesting to examine that how the species prevent niche-overlap between the sexes? and how the species act differently in the reproductive roles of the sexes? Sexual dimorphism on the shell of L. brevicula was examined with 211 periwinkles larger than 5 mm shell length in Pusan, Korea. Sexual dimorphism was detected in the aperture length only. Aperture length of the female was longer than that of the male. A difference in the sexual role in the reproduction seems to be a probable explanation for the sexual dimorphism in the aperture length. The reproductive role of the male is to choose the best female and to transfer the sperm successfully by copulation, and the role of the female is to spawn their fertilised eggs into the seawater successfully. Perhaps females migrate to lower elevations on the shore than the males, so that they are submerged when they spawn. Because wave action at the lower area of the shore is stranger than that at the higher area on the shore, the females might need larger aperture size than the males to avoid dislodgement.

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