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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 70 (1967), S. 169-177 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Fifteen alcohol-soluble carbohydrates have been isolated from logphase cultures of Tetrahymena. Preliminary results obtained by parallel chromatography of impure extracts indicate that some of the soluble components were 2-D-deoxyribose, ribose, mannose, fructose, arabinose, xylose, and glucose. Another elution gradient with extracts from cells washed several times, indicates that maltose and glucose were the only identifiable components as compared with 18 known standards. Differences were observed in the alcohol-soluble carbohydrate content in log-phase versus stationary-phase cells. For example, it is clearly indicated that component 13 is missing in stationary-phase cells while component 15 is missing in log-phase cells. Fifteen alcohol-soluble carbohydrates have been chromatographed from synchronized cells. All of these compounds show cyclic variation in relation to cell division. Component 13 accumulates in cells blocked in morphogenesis and decreases as oral development proceeds in synchronized cells.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 70 (1967), S. 35-64 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Experiments will be described which demonstrate that the product of purified “Qβ-replicase” is fully competent to serve both as a template and as a program for the synthesis of complete virus particles. The use of mutant RNA has permitted the demonstration that nucleic acid is the instructive agent in the replication process and hence satisfies the definition of a self-duplicating entity. Methods have been devised to examine the product both physically and biologically with a minimum of manipulation and with complete recovery of product and input template. A detailed analysis of every interval of synthesis has thus become possible. These technical advances have permitted us to demonstrate the existence of a latent period prior to the appearance of the first new complete infectious RNA molecules. Further, this latent period is accompanied by an eclipse of the input templates as infectious agents. The use of electrophoretic separation on acrylamide gels has yielded a detailed account of both templates and early product during the latent period, with the consequent identification of the intermediate stages. The resulting data and their implications for the mechanism of RNA replication will be discussed.
    Additional Material: 29 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 71 (1968), S. 133-150 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cellular and subcellular events in the anamnestic response were considered. Rabbits previously immunized with key hole limpet hemocyanin (KLH) were given an anamnestic challenge in the hind footpads. The popliteal lymph nodes were removed at intervals after immunization and the following correlated on a temporal basis: the changes in the number and types of cells in the lymph nodes; the formation and regression of ribosomes, polyribosomes, endoplasmic reticulum and Golgi apparatus in plasma cells; the changes in intracellular immunofluorescence for anti-hemocyanin; and, the incorporation of 14C labeled amino acids by lymph node cells into anti-KLH during a brief in vitro culture period.Maximum intracellular fluorescence for anti-KLH and the largest incorporation of 14C labeled amino acids into antibody occurred between the third and fourth day after immunization. During this interval highly differentiated plasma cells were most numerous with respect to the total cellular population. These events took place in a 12 to 24 hour period.This was followed by an abrupt decline in the synthesis of antibody. Coincident with this was a reduction in the number of recognizable plasma cells in the nodes, diminished intracellular fluorescence for anti-KLH and a simplification of the cytoplasm of the plasma cells toward a lymphocytic form.
    Additional Material: 9 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 72 (1968), S. 219-230 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 74 (1969), S. 239-240 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Assemblies of protein molecules represent a fundamental level of biological organization. The dynamic behavior of these systems-including both the assembly process and functional rearrangements-may be accounted for by the specificity of the protein interactions, which depend on environmental conditions. Analysis of the self-assembly of virus particles has established that the design of an ordered structure can be built into the specific bonding properties of the constituent proteins. Any structure which can change its state of organization is, by definition, polymorphic. The distinctive aspect of polymorphism in protein structures, contrasted with nonliving states of matter, is that the molecular design has been selected to carry out a function and that this function is part of an integrated system. The differences in molecular conformation and arrangement in all polymorphic structures-for example, allosteric enzymes or ice crystals-depend on the intrinsic interaction properties of the molecules themselves. The structures of ice and water illustrate relations between specificity and polymorphism which are relevant to the form and function of protein assemblies.Two types of polymorphism can be distinguished: modal polymorphism, which is externally moderated, as in phase transitions between different crystals forms; and positional polymorphism, which is internally moderated, as in the different disposition of identical molecules within a single crystal lattice. Positional polymorphism, exemplified by the quasi-equivalent bonding of icosahedral virus coat proteins and the different arrangement of myosin and paramyosin at the center and polar portions of the bipolar filaments, results from specific interactions that are not compatible with a strictly equivalent packing of identical molecules. The structural rearrangements in muscle contraction and the switching between the oxy and deoxy forms of hemoglobin represent the formation of different structures in response to altered external conditions. The different structural states of many protein assemblies are characterized by conserved connections which may be regarded as providing the framework for functional rearrangements. The types of polymorphism displayed by hemoglobin, virus, and muscle proteins demonstrate the relevance of the simple view that the function of a protein is determined by the potential structures it can form.
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  • 6
    Electronic Resource
    Electronic Resource
    Philadelphia : Wiley-Blackwell
    ISSN: 0095-9898
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: An effort has been made to ascertain the site of calcium uptake in rabbit psoas muscle by electron microscopy. Following a brief glycerol extraction, small groups of fibers were exposed in a suitable electrolyte environment to calcium and ATP. Conditions were such that calcium was accumulated as an insoluble oxalate salt. Conventional preparatory procedures for electron microscopy were modified so that the calcium oxalate deposits were retained in situ in ultrathin sections. These were found localized in the longitudinal component of the sarcoplasmic reticulum including the terminal dilatations which form the outer elements of the triads. The possible participation of the intermediate element of the triad in the uptake of calcium could not be determined. The results are regarded as direct evidence that the sarcoplasmic reticulum is intimately concerned with the uptake and release of calcium associated with the contraction-relaxation cycle.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 123 (1968), S. 429-439 
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Daily subcutaneous injections of cortisone acetate (0.5, 1.5 or 2.5 mg) were given to three groups of mice for seven consecutive days. Daily systolic blood pressures of the anesthetized mice were obtained by adapting the method of Friedman and Freed ('49). The maximal arterial pressure increase for the 0.5, 1.5 and 2.5 mg groups was 22%, 31% and 41% respectively. This supports the conclusion that cortisone produces hypertension in mice when administered in large doses. Mural hyalinization, vacuolization and cellular proliferation of coronary arteries were greatest in the 0.5 mg group. The highest incidence of myocardial necrosis, 56%, was in the group receiving 2.5 mg of cortisone daily. The frequency and severity of myocardial and renal cortical necrosis were directly related to the size of the cortisone dose. Adrenal medullary vacuolization and lipid infiltration of the liver were common in all experimental groups.
    Additional Material: 4 Ill.
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 67 (1966), S. 93-100 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Methods have been developed which permit measurements of cardiac output and sampling of mixed venous and arterial blood in the elasmobrach, Squalus acanthias. These methods have been utilized to characterize some of the parameters involved in gill gas exchange. A total of 17 animals have been studied with the following results. Cardiac output: 1.49±0.57 1/kg/hr.; V̇o2: 38.3±22.1 ml/kg/hr.; V̇co2: 32.1±19.0 ml/kg/hr.; RER: 0.92±0.17; PaO2: 104±27 mmHg; Pv̄o2: 18±8.8 mmHg; PaCO2: 2.9±0.75 mmHg; Pv̄co2: 4.6±1.1 mmHg; CaO2: 3.8±0.75 vol. %; Cv̄o2: 1.26±0.59 vol. %; pHa: 7.52±0.10 units; Pv̄: 7.42±0.11 units; [HCO3-]a: 3.92± 1.14 meq/1; [HCO3-]v̄: 4.80±1.15 meq/1; [dissolved CO2]a: 0.17± 0.04 mM/1; [dissolved CO2]v̄: 0.24±0.04 mM/1; [lactate-]a: 13.47±7.17 meq/1; [Lactate-]v̄: 13.01±8.18 meq/1. Some of the mechanisms involved in gill gas exchange have been characterized.
    Additional Material: 1 Tab.
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 67 (1966), S. 141-147 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Frog sciatic nerves were incubated for 24 hours in either glycine, aspartic acid, glutamic acid, lysine, leucine, γ-aminobutyric acid, glutamine, or pentanedioic acid (all labeled with C14), and the rates of release of these compounds were monitored under resting conditions and during stimulation. Upon stimulation, the rate or release of glutamic acid increased an average of 200% above the resting rate. This extra release is highly specific with regard to molecular size and structure, since of the compounds tested only glutamic acid gave significant increases in rates of release during stimulation. Ouabain (0.1 mM) had no effect on the rate of release; however, sodium azide (0.2 mM or 1.0 mM) completely eliminated the extra release during excitation, indicating that the increased permeability to glutamic acid is energy-dependent. Competition experiments show that the extra release of glutamic acid can be eliminated with 10 mM concentrations of non-isotopic choline. The hypothesis is advanced that glutamic acid is actively extruded by a highly specific carrier mechanism.
    Additional Material: 8 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 67 (1966), S. 281-284 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A linear relationship was demonstrated between the reciprocals of the concentration of free hematoporphyrin and the moles of hematoporphyrin taken up by the platelet in the dark. radiated platelets took up more hematoporphyrin than did controls; this increase in uptake was accounted for by the movement of the dye across the damaged membrane of the cell. platelets irradiated at 4°c remained impermeable to hematoporphyrin until warmed to 37°c. during the initial three to four minutes of exposure to light at 37°c, there was no additional uptake of hematoporphyrin by platelets in comparison to controls. between six to ten minutes irradiation, the uptake of hematoporphyrin increased linearly with the log time of irradiation. thereafter, no further uptake occurred. a further increase in uptake of dye was demonstrated by both control and irradiated platelets at a reduced ph. this study enables a correlation to be made between the effects of hematoporphyrin on the platelet and the uptake of this agent by the platelet.
    Additional Material: 2 Ill.
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