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  • 1
    ISSN: 1432-2048
    Keywords: Chlorophyll fluorescence ; Commelina ; Guard cell ; Oxygen evolution (guard cell) ; Photosystem II ; Protoplast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Guard-cell protoplasts were isolated by enzymic digestion of the epidermis peeled from the abaxial surface of leaves from Commelina communis L. The protoplasts were separated from mesophyll-cell protoplasts and other contaminants by density-gradient centrifugation, and the purity of the preparations carefully and quantitatively assessed by light microscopy. The preparations of guard-cell protoplasts were then compared with mesophyll-cell protoplasts in terms of the activity of photosystem II as assessed by a) the light-induced evolution of oxygen under both steady-state and flashing light and b) the characteristics of photosystem-II chlorophyll fluorescence. In all experiments, clear photosystem-II activity was found in guard-cell protoplasts, although some subtle distinctions between guard-cell and mesophyll-cell protoplasts were found. The contribution of any contaimination by mesophyll-cell chlorophyll to guard-cell-protoplast signals was estimated to be less than 3% in all cases. The results indicate that photosystem II is present and active in guard cells of Commelina.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-7217
    Keywords: bone scans ; breast cancer ; follow-up ; treatment failure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A considerable fraction of first metastases in breast cancer patients are found in the skeletal system. Consequently, to improve the probability of detecting bone lesions, protocols of the National Surgical Adjuvant Breast and Bowel Project (NSABP) have required radionuclide scans every six months for the first three postoperative years and yearly thereafter. The present study was conducted to evaluate the worth of 7984 bone scans performed prior to documentation of first treatment failure on 2 697 stage II (positive node) patients entered into NSABP clinical trial B-09. At the time of evaluation, there were 779 patients with a treatment failure, 163 (20.9%) of whom had their recurrence limited to bone. At most, 52 (0.6%) of the total number of screening scans were efficacious in detecting lesions in asymptomatic patients. As a result of this minimal benefit from routine scans, it was recommended that they be conducted less frequently. In presently ongoing NSABP studies, asymptomatic patients having tumors with positive axillary nodes receive scans at yearly intervals for the first three years. Future NSABP trials will require follow-up bone scans only as indicated by symptoms.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 230 (1983), S. 219-223 
    ISSN: 1432-0878
    Keywords: Steroid receptors ; Estradiol ; Diabetes mellitus ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Previous clinical studies have indicated that during pregnancy and following administration of contraceptives women show altered carbohydrate metabolism. We performed autoradiographic studies using 3H-estradiol-17β and 3H-dihydrotestosterone on male and female baboons. Discrete sites of localization of exposed photographic emulsion were observed over nuclei of cells of the islets of Langerhans of the pancreases of baboons injected with estrogen but not over those of baboons injected with androgen. These observations that islet cells contain specific receptors for estrogen when combined with the clinical observations, suggest that estrogens have a direct effect on the islet cells that may modulate the release of insulin.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 231 (1983), S. 593-601 
    ISSN: 1432-0878
    Keywords: Lymphatic organs ; Sex steroids ; Baboon ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The localization of radiolabeled estradiol and dihydrotestosterone was examined in the lymphatic organs of both male and female baboons. A total of 12 baboons were divided into two groups, each containing three males and three females. Each animal in one group, both males and females, was injected intravenously with 1 μg/kg body weight of 3H-estradiol while those in the second group were each injected with 1 μg/kg body weight of 3H-dihydrotestosterone. As controls, one male and one female from each group also received a dose of 100 μg/kg body weight of the corresponding unlabeled steroid. One and a half hours after the injections, the animals were sacrificed and the spleen, thymus, and inguinal lymph nodes removed and processed for autoradiography. The localization of 3H-estradiol was similar in both males and females. In the thymus fibroblasts and epithelio-reticular cells, but not thymocytes, localized 3H-estradiol. In lymph node and spleen, nonlymphoid tissue concentrated the labeled estrogen. Additionally, in the paracortical region of the lymph node, an unknown cell type was labeled with estrogen. Only one male baboon demonstrated nuclear localization of 3H-dihydrotestosterone. This was observed in the reticular cells in the spleen and lymph nodes. The same cell type in the organs of the remaining animals was unlabeled.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 215 (1981), S. 499-504 
    ISSN: 1432-0878
    Keywords: Androgen receptors ; Pituitary gland ; Rhesus monkey ; Autoradiography ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The uptake and retention of radiolabelled dihydrotestosterone by the pituitary gland was examined in the rhesus monkey. Two animals were given an intravenous injection of 1.0μg/kg 3H-dihydrotestosterone (DHT) alone while one monkey received both the labelled androgen and 100μg/kg of unlabelled steroid. One and a half hours later, they were sacrificed. The pituitary glands were removed and processed for autoradiography and immunocytochemistry. Autoradiographic localization of DHT was discernible in the partes nervosa, intermedia and distalis, albeit the highest concentration of radiolabelled cells was noted in the pars distalis. Immunocytochemical staining with antibodies to rat PRL, human TSHβ and ovine LHβ revealed a population of steroid-concentrating cells that contained TSH and a second group that contained LH. None of the cells that reacted with the anti-PRL serum were radiolabelled.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 220 (1981), S. 773-780 
    ISSN: 1432-0878
    Keywords: Estrogen receptors ; Uterus ; Armadillo ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The uptake and retention of radiolabeled estradiol by the uterus was examined in the armadillo. One pregnant and two non-pregnant armadillos were treated with 1.4 μg/kg body weight of 3H-estradiol (E2) by injection into the left ventricle, and one non-pregnant animal was injected with both the labeled hormone and 140 μg/kg body weight of unlabeled E2. One and a half hour after injection, the animals were sacrificed and the uteri were removed and processed for autoradiography. In the non-pregnant animals, nuclear localization was observed in the interstitial cells and glandular epithelium of the endometrium and the connective tissue cells and smooth muscle of the myometrium. Additionally, there was a gradation of uptake in the epithelial cells of the endometrium in that the glandular cells of the basal region were heavily labeled, while those cells in the sinusoidal, and luminal regions contained successively less label. The luminal cells were poorly labeled. In the pregnant female, the smooth muscle and glandular cells hypertrophied and their nuclei contained less label than was observed in the non-pregnant animals. The arteries of the myometrium were more easily distinguished in the pregnant animals and the nuclei of the endothelial cells and smooth muscle were more consistently labeled than those of the non-pregnant armadillos.
    Type of Medium: Electronic Resource
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