Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Risk analysis 8 (1988), S. 0 
    ISSN: 1539-6924
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Exogenous agents may perturb development during the embryonic period and adversely affect the formation of organs. However, adverse effects on development are not limited to the embryonic period nor are the manifestations restricted solely to outright gross structural malformation, but may instead be expressed as a decrement or aibberration of postnatal function. Susceptibility to altered development may extend well into the postnatal period. Studies of functional parameters in several organ systems have demonstrated the broad-based susceptibility, subtlety of expression and potential of long-lasting effects of altered development assessed by physiologic assays. Adverse effects on functional development, whether in the CNS, reproductive, gastrointestinal, genitourinary, respiratory, or immune systems, etc., merit continuing investigation. From the viewpoint of risk estimation and hazard detection, evaluations of postnatal functional parameters may be relevant for several reasons. First, such parameters may serve as low-dose triggers. Second, they may be useful as a focal point for epidemiological studies. Finally, a more thorough understanding of the degree and magnitude of such postnatal functional deficits is needed since an adverse maternal effect may be transient, considered acceptable, or unperceived, but the effect on the conceptus may be permanent and severe. The immune and respiratory systems are discussed as two examples of how subtle and protean adverse effects on functional development may be.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Female Long-Evans rats, were given a purified PGA-deficient diet containing 10 mg% of the antimetabolite, 9-methyl-PGA, from days 8 to 10 of gestation, followed by a PGA-supplemented diet from day 10 to autopsy. Thisregimen resulted in 18% embryonic death by day 11, 65% by day 12, and 100% by day 13 of pregnancy.No morphological differences between PGA-deficient and control embryos were observed at nine or nine and one-half days but ten-day embryos showed retardation of growth and development and decreased mitosis, especially in the neural epithelium. In 11-day PGA-deficient embryos the cranial portion of the neural tube was markedly retarded or anomalous. PGA-deficient embryos still living on day 12 exhibited severely retarded or abnormal development of the cranial region with moderate retardation in other areas. The placentas of PGA-deficient embryos were normal until the twelfth or thirteenth day when vacuolization and pyknosis of giant cells in the junctional zone occurred. These changes as well as placental involution through day 16 appeared morphologically identical with those observed in placentas of embryosdestroyed surgically on day 12. PGA-deficiency appeared primarily to affect embryonic rather than placental tissues.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 149 (1964), S. 49-55 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A purified diet lacking folic acid and containing 20 mg% of the antimetabolite, 9-methyl pteroylglutamic (folic) acid was fed to female Long-Evans rats during days eight and nine of pregnancy. Embryos were removed at autopsy on the tenth day of gestation for study and comparison with embryos from normal control pregnancies.Analysis of mitotic counts revealed that 18.6% of the cells in control embryos were in mitosis in contrast to only 5.7% in PGA-deficient embryos. A disproportionate reduction in anaphase and telophase stages was observed in conjunction with an increased percentage of cell at metaphase. Concomitantly with these mitotic changes a marked reduction in histochemically demonstrable RNA and in numbers of ribosomes as revealed by electron microscopy was observed.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...