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The effect of a 20% Hanks [correction of Hanx] solution on living cells of pig embryo kidney culture induces sharp changes in the structural and functional organization of nucleoli. 10-15 min after the beginning of the effect, no nucleoli are observed under the light microscope. The ultrathin sections reveal only fibrillar centers (FC) and a dense fibrillar component. Under these conditions nucleoli do not incorporate 3H-uridine. However, 30-120 min after the cells are transferred from the hypotonic to the normal isotonic medium, the nucleoli cannot be distinguished from initial ones by their form, size, location in the nucleus, ultrastructure and the 3H-uridine labelling pattern. This indicates that the effect of a 20% Hanks [correction of Hanx] solution on nucleoli of living PE cells is reversible. It has been suggested that reconstruction of nucleoli in the full culture medium may proceed at the expense of both synthesis de novo and the material of initial nucleoli. 相似文献
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IuF Bogdanov TM Grishaeva OL Kolomiets IuS Fedotova 《Canadian Metallurgical Quarterly》1996,32(11):1474-1493
Chromosome synapsis in meiosis is performed through the formation of a synaptonemal complex (SC). The SC aggregates homologues until the diplotene stage, when the function of physical binding is carried out by a chiasmata. SC formation is controlled by specific genes. Regularities of SC formation in animals and plants are being studied at the Laboratory of Cytogenetics, Vavilov Institute of General Genetics, the Russian Academy of Sciences. It was shown that, in Drosophila melanogaster, the presence or absence of SC in meiosis is determined by balance between autosomes and sex chromosomes. i.e., SC is formed according to regularities in sex determination. The dose of the 8C-11A segment of X chromosome plays a key role in this process. Eight mutations in synaptic genes that affect SC formation were studied in rye Secale cereale. SC variants occurring in heteromorphic sex chromosomes were analyzed in the Ellobius genera and in B-chromosomes of Apodemus peninsulae. It was shown that, in addition to homologous synapsis, non-homologous synapsis of aberrant chromosomes occurs in rye and mouse heterozygotes at chromosome rearrangements. Twice as many heterozygous chromosome rearrangements were revealed, when the SC was studied at pachytene instead of diakinesis and metaphase I. Simple methods of SC investigations extended the capabilities of cytogenetic analysis of meiosis and provided new perspectives for studying the action of meiotic gen. 相似文献
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Skin injury alive produces quick and distinct increase of free histamine and serotonin. A fluorimetric method for detection of these compounds in tissues has been the only one described in the literature up to now but it needed a time consuming extraction and big amount of primary material (about 3 g of skin devoid of subcutaneous fat tissue) as well. The authors succeeded in substituting the method and developed a voltametric detection of histamine and serotonin using the computerized ECO-TRIBO-Polarograph. It enabled to omit the extraction of skin compounds and to decreased the amount of primary tissue to a quarter. The detection of free histamine and serotonin levels is presumed to enable a more accurate determination of the time of injury, particulary in short interval before death; it presents, with a simultaneous of glycophorin, a convenient complementation of immunohistochemical investigation of fibronectin. 相似文献
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IuS Polushin ET Rostomashvili AI Levshankov AL Kostiuchenko GP Bogatova 《Canadian Metallurgical Quarterly》1998,(5):42-44
Caudal epidural anesthesia for interventions on the lower limbs and pelvic organs was used in 525 patients. A specific feature of the method is use of hypoosmolic local anesthetic solution (osmolality 260 mosmol/kg) containing lidocaine, 0.9% sodium chloride, and distilled water. Pathologic studies showed that in adult patients, at least 40 ml anesthetic should be injected into the caudal canal for adequate blocking. During surgery, caudal epidural anesthesia reliably protected from surgical trauma without side effects for respiration and circulation. The duration of analgesic effect was 3 +/- 0.5 h and even longer, if local anesthesia was potentiated with sedative drugs. No complications were observed, failures occurred in 5.2% cases. The method is simple and reliable and is recommended for practice. 相似文献
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