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  • 1
    ISSN: 1573-5060
    Keywords: Avena sativa ; chlorophyll content ; leaf color ; leaf thickness ; senescence ; protein breeding programs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Growth room experiments were conducted to study associations of grain protein content with properties of seedling leaf sections of oats (Avena sativa L.) using (1) 10 cultivars differing genetically in grain % protein, and (2) 10 populations of a single high protien cultivar (Hinoat) differing phenotypically in grain % protein. These populations, which were derived from a nitrogen fertilizer experiment, had grain protein concentrations which varied over the whole range displayed by the high and low protein cultivars when the latter were tested in a conventional field trial. Seedling leaf % protein was closely associated with grain % protein in both (1) and (2). Chlorophyll content per unit leaf area and leaf dry weight per unit leaf area were significantly higher in the high than in the low protein cultivars, and were significantly higher in all the Hinoat populations than in the low protein cultivars. Excised seedling leaf sections were placed on filter paper moistened with 1 ppm kinetin solution and kept in the dark at 25°C. After 96 h chlorophyll content per unit leaf area was again significantly higher in the high protein cultivars and in all the Hinoat populations than in the low protein cultivars, and the consequent differences in leaf colour were then readily visible. Absolute amounts of chlorophyll lost per unit leaf area were similar in all cultivars and populations, but the low protein cultivars showed a greater proportional loss (as % of initial content). A colour scale was used to visually rate the senesced leaf sections. The visual rating allowed the rapid separation of the high and low protein cultivars, and there was no significant variation in the ratings of the Hinoat populations. It is suggested that this procedure may be useful in the early selection phases of protein breeding programs for screening large populations rapidly at the seedling stage to detect genetic differences in potential grain protein content.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The fine structural changes accompanying the regeneration of adrenocortical transplants in the rat were studied with the electron microscope. One-half gland autotransplants were made to the dorsal musculature of male Wistar rats, weighing approximately 120 gm. Transplants were recovered after 2, 4, 7, 14, 21 and 60 days of regeneration. During the first week of regeneration there was an increase in the granular endoplasmicreticulum at the expense of the agranular form. The internal structure of the numerous mitochondria was transformed from the normal tubular and vesicular forms of the zonae glomerulosa and fasciculata, respectively, to a lamellar type. The quantities of free ribonucleoprotein particles also were reduced. During this period the viable cortical cells are considered to be more deeply involved in protein synthesis and growth rather than hormone biosynthesis. Following 14 days of regeneration and thereafter, the characteristics of the mal intact adrenal cortex became established. Highly osmiophilic “dark cells,” present in the inner zones of the normal intact adrenal cortex, firstappeared after 14 days of regeneration, and were widely scattered throughout the cortexafter three weeks. After two months of regeneration, the “dark cells” were again concentrated in the inner cortical zones. During this latter period, hormone biosynthesis appears to be the major cell function. Possible structural-functional relationships are discussed.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The purpose of this study was to determine the dimensions of capilaries in various tissues, in vivo, in frogs, mice, and pups. Capillaries were measured in the web, strap muscles of the neck, mesentery and bladder of frogs, and in the mesentery of mice and pups. The light source was a fused quartz rod transilumination apparatus. In all cases the exposed tissues were kept moist by a continuous flow of Ringer's solution over their surfaces.The mean values found for the tissues of the frog are web 11.94 μ, skeletal muscle 11.30 μ, mesentery 11.97 μ, and bladder 11.40 μ. The mesenteric capillaries of the mice and pups had a mean value of 4.64 μand 7.36 μ respectively.Difficulties encountered during the course of observation included vibrations of the optical equipment, movement of the tissue under the microscope, fogging of the objective lens, and the determining of which of the microscopic vessels were “capillaries.”A statistical analysis of the data indicates that the variance in the measurements recorded on the capillaries of a single animal is greater than the variance from animal to animal.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Snell adrenocortical tumor 494 was implanted into male Sprague-Dawley rats and recovered 7, 14, 21, 28 or 35 days following initial detection by palpation (7-10 days following transplantation). Electron microscopic, stereologic and biochemical analyses of the tumor were compared to adrenals of normal animals to serve as a baseline for further studies of the effects of chemotherapeutic agents on tumor cells. Tumor cells possessed oval or elongated mitochondrial profiles with tubular cristae, one or two very large (〉 5μ) lipid droplets, abundant ribosomes and coated vesicles, and sparse rough and smooth endoplasmic reticulum. Stereologic evaluation revealed that tumor lipid volume was 41% and mitochondrial volume 29% that of the normal adrenal controls. Tumor nuclei were 2.5 times larger than adrenocortical nuclei while cellular volumes were similar. On a net weight basis, tumor cholesterol was 55%, cholesterol ester 2.2%, and lipid phosphate 25% of respective mean values for normal adrenal glands. The tumor cholesterol: cholesterol ester ratio progressively decreased with time, but remained 18-fold greater than the normal adrenal. Plasma corticosterone levels in tumor-bearing rats were elevated 3-fold by 14 days after initial detection. The adrenals of the tumor-bearing host exhibited marked involution, the extent of which was directly related to tumor size.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Philadelphia : Wiley-Blackwell
    Journal of Cellular and Comparative Physiology 62 (1963), S. 87-94 
    ISSN: 0095-9898
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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