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411.
Previously, we identified a 215 kd glycoprotein, GP215, which is associated with postovulatory oocytes and embryos, but not with preovulatory oocytes (Kapur and Johnson, '85). In this paper a polyclonal antibody that specifically recognizes GP215 has been used to study the distribution of the molecule in association with ova and preimplantation embryos and in the female reproductive tract. GP215 is present in epithelial cells lining the cranial portions of the oviduct and in oviductal fluid, ovarian bursal fluid, and medium conditioned by oviductal tissue in vitro. Immunofluorescence assays of the ovum and early embryo show that GP215 is sequestered in the perivitelline space. Since preovulatory oocytes exposed to bursal fluid in vitro acquire GP215, we hypothesize that GP215 is synthesized and secreted by the oviductal epithelium and secondarily associates with the ovulated oocyte. Sequestration of GP215 within the perivitelline space is relatively specific since mouse serum albumin, a major constituent of oviductal fluid, and other high molecular weight proteins are not similarly retained. These observations indicate that the composition of the perivitelline space may be significantly different from the greater environment external to the zona pellucida such that fertilization and early development of mammalian ova potentially take place in a distinct perivitelline microenvironment.  相似文献   
412.
This study documents a molecular change in the murine ovum related to its exposure to oviductal fluid. Wheat germ agglutinin (WGA) identifies a 215-kDa glycoprotein band (GP215) that is associated with ovulated oocytes and early embryos obtained from the oviduct, but is absent from preovulatory oocytes. GP215 is present in ovarian bursal fluid, oviductal fluid, oviductal epithelial cell extracts, and medium conditioned by oviductal tissue in vitro. Preovulatory oocytes acquire GP215 after in vitro incubation in ovarian bursal fluid. Thus, it appears likely that GP215 is secreted by the oviductal epithelium and becomes intimately associated with the ovum following ovulation.  相似文献   
413.
Objectives To establish changes over time in the frequency of homicides committed by strangers, and to describe the personal and clinical characteristics of perpetrators of stranger homicides.Design Longitudinal study and national clinical survey.Participants People convicted of homicide in England and Wales between 1996 and 1999 and whether the victim was known to the perpetrator.Setting England and Wales.Main outcome measure Characteristics of perpetrators of homicides according to whether victims were strangers or not.Results Stranger homicides increased between 1967 and 1997, both in number and as a proportion of all homicides. No increase was found, however, in the number of perpetrators placed under a hospital order after homicide, whether all homicides or stranger homicides only. 358 of 1594 (22%) homicides were stranger homicides. In these cases the perpetrator was more likely to be male and young. The method of killing was more likely to be by hitting, kicking, or pushing (36% (130 of 358) for victims who were strangers to the perpetrator compared with 14% (145 of 1074) for victims who were known). Perpetrators were less likely to have a history of mental disorder (34%, n = 80 ν 50%, n = 142), a history of contact with mental health services (16%, 37 of 234 ν 24%, 200 of 824), and psychiatric symptoms at the time of the offence (6%, n = 14 ν 18%, n = 143). They were more likely to have a history of drug misuse (47%, n = 93 ν 37%, n = 272); alcohol (56%, n = 94 ν 41%, n = 285) or drugs (24% n = 44 ν 12%, n = 86) were more likely to have contributed to the offence.Conclusions Stranger homicides have increased, but the increase is not the result of homicides by mentally ill people and therefore the “care in the community” policy. Stranger homicides are more likely to be related to alcohol or drug misuse by young men.  相似文献   
414.
Numerous naturally-occurring and synthetic compounds that were discovered initially because of their toxic properties, were later shown to possess biological activities beneficial to humans that enabled them to serve as templates for the development of useful medicinal agents. A prominent example is thalidomide, a synthetic drug that gained notoriety originally due to its catastrophic teratogenicity in humans. The discovery of thalidomide's efficacy in treating several diseases has resulted in the recrudescence of the drug to society's usage. A current example of this phenomenon is the plant teratogen cyclopamine (11-deoxojervine), whose deleterious terata-inducing effects were restricted to grazing animals, but whose recently discovered inhibition of Sonic hedgehog signal transduction has provided both the potential to increase our understanding of organogenesis and to serve as a lead compound in drug development.  相似文献   
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