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61.
62.
Summary A new case of triploid-diploid mosaicism in the lymphocytes of a newborn with multiple malformations is reported, and the origin of the mosaicism is briefly discussed.N.I.H. International Post-doctoral Fellow.Bevoegd Navorser N.F.W.O. 相似文献
63.
Terminal Disinfection in Hospitals with Quaternary Ammonium Compounds by Use of a Spray-Fog Technique
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Spray-fogging of hospital rooms with a quarternary ammonium disinfectant was found to be an effective means of reducing the number of detectable airborne and surface bacteria. The level of bacterial contamination in hospital rooms was determined before and after fogging by means of the gravitational fallout method, the petri dish swab technique, and volumetric air-sampling procedures. Rooms vacated by patients infected with staphylococci, streptococci, pseudomonads, and salmonellae were tested and found to be effectively decontaminated of most of the detectable organisms by the fogging procedure. 相似文献
64.
Staphylococcal hyaluronate lyase (hyaluronidase) derived from a pathogenic strain of staphylococcus was purified by means of salt fractionation with ammonium sulfate and gel filtration through Sephadex G-100. Most of the enzyme activity from concentrated culture supernatant fluids of staphylococci was obtained in a fraction precipitated by 90 to 100% saturation with ammonium sulfate. A small amount of enzyme was also precipitated by 80 to 90% saturation with the salt. The hyaluronidase-rich fractions did not contain other staphylococcal enzymes, such as coagulase, protease, lipase, and staphylokinase. These enzymes were present in the original concentrates. Molecular sieving chromatography of the partially purified enzyme by filtration through Sephadex G-100 resulted in a further increase in specific enzyme activity. However, more than one active peak was obtained after gel filtration, thus suggesting that there may be more than one molecular form of the enzyme. Immunodiffusion in agar gel of the chromatographically purified enzyme fraction, with immune serum from rabbits injected with concentrated staphylococcal culture supernatant fluids, indicated that there was one major antigen. A similar antigen, giving reactions of identity with the purified material, was present in the original culture supernatant fluid. 相似文献
65.
Studies on renal aldosterone-binding proteins 总被引:9,自引:0,他引:9
66.
Electrical Properties of the Membranes of the Pleuropneumonia-Like Organism A 5969 总被引:2,自引:0,他引:2
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The electrical properties of the pleuropneumonia-like organism A 5969 have been determined over the frequency range from 0.5 to 250 Mcps. The frequency dependence of the dielectric constant and conductivity of PPLO suspensions is completely consistent with the existence of a membrane. The PPLO has an internal conductance which in part reflects its ionic equilibrium with normal nutrient and macromolecular constituents. But it is fairly independent from variation in external ionic strength. 相似文献
67.
THE DEGENERATIVE CHANGES IN PANCREATIC ACINAR CELLS CAUSED BY DL-ETHIONINE 总被引:24,自引:3,他引:21
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Degeneration of pancreatic acinar cells in rats injected with ethionine was studied by electron microscopy. The most conspicuous morphologic lesions occurred in the ergastoplasm. There was a widening of the endoplasmic reticulum, a decrease in number of membrane-associated ribosomes, and a development of fine and coarse vacuoles containing agranular disoriented membranes. Cytoplasmic ribosomes unassociated with membranes were less numerous. Nuclear changes consisted of a coarsening and clumping of the nuclear chromatin, chromatin margination, and increased osmiophilia and vacuolation of the nucleolus. Eight to ten days after the beginning of ethionine injections, changes in zymogen granules, mitochondria, and the Golgi apparatus appeared, but only after extensive damage to the acinar cell. The effects were consistent with ethionine's known interference with protein metabolism but also suggest disturbance in ribonucleic acid metabolism. The ergastoplasmic changes after ethionine were similar in some respects to the early lesions produced in liver parenchymal cells by fasting, to the changes occurring in animals on protein-free diets, or to some of the liver changes produced by azo dye carcinogens. The ribosomal and ergastoplasmic changes represent early morphologic expressions of the biochemical effect of ethionine. 相似文献
68.
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70.
An Electron Microscope Study of the Salamander Thyroid during Hormonal Stimulation 总被引:6,自引:4,他引:2
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Lawrence Herman 《The Journal of cell biology》1960,7(1):143-150
Cytological changes in thyroid glands following administration of thyroid-stimulating hormone (TSH), were studied in adult salamanders, Ambystoma tigrinum, Triturus torosus, and Triturus viridescens by electron and light microscopy. Thyroids from untreated salamanders contained large follicles, faintly basophilic colloid, low follicle cells with flattened nuclei, and scant, slightly basophilic cytoplasm. After TSH administration the cell height and nuclear volume increased. Cytoplasmic basophilia was markedly increased and follicle lumina were reduced. In electron micrographs, stacks of ergastoplasmic lamellae appeared near the nucleus occasionally in contact with the nuclear membrane. In more advanced stages of stimulation, lamellar arrays were largely replaced by small disoriented vesicles and larger vacuoles containing colloid-like material. Sections of obliquely oriented ergastoplasmic membranes contained rows of extremely fine particles. Microvilli increased in size and number and Golgi structures became more extensive. Homogeneous osmiophilic droplets increased in size and abundance. Some of the smaller droplets were seen associated with the Golgi zone. Droplets similar in size and density frequently contained closely packed, whorled lamellae. Mitochondria showed no structural changes but occurred in aggregates interposed between the nucleus and highly folded portions of the basal cell membrane. 相似文献