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881.
Frederick Crescitelli 《The Journal of general physiology》1963,47(1):33-52
Retinal extracts of Gekko gekko were found to contain two retinene1 photopigments, one with maximum absorption at about 521 mµ, the second with a maximum in the region of 478 mµ. These pigments were assayed by the method of partial bleaching and their spectral characteristics studied by examining their difference spectra. The 478 mµ pigment was present in the extracts as 8 per cent of the total photopigment concentration. The two pigment systems were shown to be biochemically independent and to have different properties. Unlike the 521 mµ pigment, for example, the 478 mµ pigment was found to resist the action of NH2OH and, within the cells, to be unaffected by sucrose solutions. These solutions destroyed or altered the 521 system so that extracts of sucrose-treated retinae were found to contain significantly less 521 photopigment. In digitonin solution the 521 pigment was unaffected by sucrose treatment. Both pigments were extracted from separated, washed outer segments and so are considered to be visual pigments. This dual system accounts for the spectral sensitivity of this gecko as determined by Denton. A search was made, but no evidence was secured for the presence of a photopigment absorbing at longer wavelengths. Electoretinographic data suggest, however, that an elevated sensitivity at longer wavelengths occurs in some geckos so that a continued search is justified for a third photopigment. 相似文献
882.
Symposium on Relationship of Structure of Microorganisms to Their Immunological Properties: II. HOST-REACTIVE PROPERTIES OF CELL WALLS AND PROTOPLASM FROM MYCOBACTERIA 总被引:2,自引:1,他引:1
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883.
The effect of flurandrenolone, 0.05%, in a cream base was compared with that of hydrocortisone, 1%, in the same base in 35 cases of atopic dermatitis, using contralateral application technique. The efficacy of flurandrenolone was found to be superior to that of hydrocortisone in 23 instances and equal in 12 cases. A fourfold dilution of this cream, flurandrenolone 0.0125%, was compared with 1% hydrocortisone cream in 18 patients and similar results were obtained. The superiority of flurandrenolone was particularly evident during the first week of application. The therapeutic efficacy of small amounts of flurandrenolone results in economic advantage to the patient and enables him to use applications of this preparation more freely. 相似文献
884.
LOCALIZATION OF MACROMOLECULES IN ESCHERICHIA COLI : II. RNA and its Site of Synthesis 总被引:7,自引:3,他引:4
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![点击此处可从《The Journal of cell biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The distribution of RNA in cells of E. coli 15 T-U- labeled with uridine-H3 was studied by methods involving the analysis of radioautographic grain counts over random thin cross-sections and serial sections of the cells. The results were correlated with electron microscope morphological data. Fractionation and enzyme digestion studies showed that a large proportion of the label was found in RNA uracil and cytosine, the rest being incorporated as DNA cytosine. In fully labeled cells the distribution of label was found to be uniform throughout the cell. The situation remained unchanged when labeled cells were subsequently treated with chloramphenicol. When short pulses of label were employed a localization of a large proportion of the radioactivity became apparent. The nuclear region was identified as the site of concentration. Similar results were obtained when cells were exposed to much longer pulses of uridine-H3 in the presence of chloramphenicol. If cells were subjected to a short pulse of cytidine-H3, then allowed to grow for a while in unlabeled medium, the label, originally concentrated to some extent in the nuclear region, was found dispersed throughout the cell. The simplest hypothesis which accounts for these results is that a large fraction of the cell RNA is synthesized in a region in or near the nucleus and subsequently transferred to the cytoplasm. 相似文献
885.
An investigation of the pulmonary fibrinolytic enzyme system in 31 infants who died with hyaline membrane formation was reviewed. There was complete lack of plasminogen activator activity in the lungs of 84 per cent of these infants. This phenomenon was shown to result from an abnormal inhibitor. A comparable inhibitor was found in normal placental tissue, and it is postulated that this inhibitor is released into the circulating blood as the result of placental infarction. Fibrin, a basic component of the hyaline membrane, is probably precipitated from a physiological capillary transudate associated with the formation of amniotic fluid by the lungs. The presence of an inhibitor of fibrinolysis would then result in the accumulation of intrapulmonary fibrin and the formation of hyaline membranes. 相似文献
886.
Edwin J. Wylie Joseph S. McGuinness Frederick M. Binkley 《The Western journal of medicine》1957,87(2):71-74
In 32 cases aneurysms of the aorta and peripheral arteries were resected and replaced by grafts. The results from the use of homografts in 18 cases were more satisfactory than with the use of Ivalon in 14 cases. The abdominal aorta was the most frequent location of aneurysms.The current mortality rate of 5.5 per cent for resection of unruptured abdominal aneurysms indicates that resection and grafting are an effective means of reducing the high mortality of untreated aneurysms. Five ruptured aneurysms were excised, with a mortality rate of 40 per cent. The uniformly fatal outcome of untreated ruptured abdominal aneurysms makes it obligatory for the surgeon to operate immediately after the diagnosis is first made. 相似文献
887.
888.
889.
J. Hughlings Jackson Thomas Buzzard R. Brudenell Carter H. Charlton Bastian W. R. Gowers David Ferrier J. A. Ormerrod Charles E. Beevor Howard H. Tooth James Taylor J. S. Risien Russell W. Aldren Turner Frederick E. Batten Felix Semon Victor Horsley Charles A. Ballance R. Marcus Gunn A. E. Cumberbatch 《BMJ (Clinical research ed.)》1900,2(2066):333
890.