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51.
Abstract— The mechanism of electroshock (ES)-induced inhibition of protein synthesis in rabbit cerebral cortex has been investigated by using a cell-free system. The protein biosynthetic activity of the post-mitochondrial supernatant (PMS) obtained from the cerebral cortex of ES-treated animals was found to be markedly lower than in controls (C). This inhibition was accompanied by a decrease of polysomes and an increase of monomers. In addition, a relative increase in light polysomes was evident at short intervals after ES treatment. No difference was found in the total soluble activity and in the activity of the elongation factors and ribonuclease present in the cell sap of C and ES animals. The biosynthetic activity of ES-total. free and membrane-bound ribosomes was approx 45% lower than that of the corresponding C fractions: polysome/monomer ratios were similarly reduced. The total content of cortical ribosomes was not affected by ES. Following ES treatment there was no change in the ribo-somal ability to elongate, terminate and release polypeptide chains, nor a decrease in the polysomal content of poly(A)-containing mRNA. These data strongly suggest that the ES-induced inhibition of protein synthesis results from a defect in the initiation process. The possible mechanisms mediating this defect have been discussed.  相似文献   
52.
In extracts obtained by treating rye embryo ribosomes with 0.5 M NH4Cl, nuclease activity was noted towards double-stranded RNA from virus of Penicillium chrysogenum and towards synthetic poly (A)-poly (U) and poly (I)-poly (C) complexes.  相似文献   
53.
A sialyl transferase activity is found in purified mitochondria. It is not due to residual contamination and this enzymatic system is located in the outer mitochondrial membrane. This proves mitochondrial autonomy in regard to glycoconjugate sialylation.  相似文献   
54.
A case of a two-year-old boy with multiple subcutaneous lesions caused by Basidiobolus haptosporus is presented.The child had also a non-toxic familial goiter and clinical and radiological features of a pulmonary illness. The pulmonary manifestations only disappeared with the treatment with potassium iodide. The authors think that the pulmonary lesions must have arisen by direct spread of the fungus from the subcutaneous lesions of the chest.  相似文献   
55.
Summary A 2-year-old girl had a de novo duplication in the long arm of one chromosome 7 and an increased level of the enzyme -glucuronidase in cultured fibroblasts. The phenotype of the girl partly overlaps those of two presumptive syndromes due to secondary partial trisomies 7q. The ratio of the enzyme activity was 1.43 to the controls, and 1.37 to her parent's values. We could not define the abnormality but suggest two alternatives: either the patient is trisomic for region q112 to q22 or for the region q22 to q34. If the second alternative is correct the locus for -glucuronidase is possibly assigned to band 7q22.  相似文献   
56.
Conclusion These American anthropological studies both reflect and distort our own Romanian-conceptions. Paradoxically, this gives both Romanian and American researchers an opportunity to verify their validity and reliability. The studies are notable for their multiplicity of theoretical approaches to Romanian reality: each author brings in something new by way of interpretation and, at the same time, maintains a dialectical conception as a methodological frame of reference.The authors are certainly conversant with present and future strategies of development in Romania. But their main problem is that they do not always understand the spirit of the latter and consequently fail to interpret contemporary Romanian realities in a deeply humanistic way.And now, some proposals. For a more active dialogue between Romanian and American scientists I suggest a more comprehensive use of the Romanian sources of information, including historical, beletristic, sociological, and political works. With reference to their reflections on history, the American anthropologists could have discussions with Romanian historians, and could use Romanian historical periodization, especially for the contemporary period. For us, the following sequence is basic: the moment of the armed insurrection as the beginning of the popular democratic revolution (August 23, 1944); proclamation of a Peoples' Republic of Romania (December 30, 1947); unification of Social Democratic Party with the Communist Party to form the Romanian Workers Party (Spring 1948); at this time it is possible to speak of a socialist revolution. The analysis of the Americans should take into consideration these important dates in Romanian history and structure their studies accordingly. Sometimes they must pay more attention to the affective connotation of words, especially for a Romanian reader. Such words would be, for example, their use of elite, rather than leaders, bureaucracy rather than administration, pressure rather than social necessities with the consciousness of development, patronclient instead of using interpersonal relations with mutual benefit, etc.I would also urge that substantive discussions between Romanians and Americans begin, built around specific topics of mutual interest, rather than ceremonial meetings which occur when the parties have neither the language skills, data nor social conceptions to interact fruitfully.I suggest to the American researchers that they maintain and strengthen their contacts with Romanian administrators at local, regional and national levels, so that their studies may contribute to our social praxis.Finally, the Americans should always take into account the economic constraints that shape political, juridical, moral, and philosophical phenomena, and try also to grasp more fully the interaction between elements of the superstructure and between superstructure and base in contemporary Romanian socialist society.Above all, along with Professor Cole , I hope that the scientific effort at interpreting Romanian reality, with its lights and shadows, will be used only for reciprocal knowledge and cooperation.Maria Cobianu-Bacanu is Scientific Researcher at the Center for Sociology, Academy of Social and Political Sciences, Bucharest, Romania.
  相似文献   
57.
58.
Effects of Chlorine Concentration on the Structure of Poliovirus   总被引:5,自引:5,他引:0       下载免费PDF全文
Chlorine concentrations below 0.8 mg/liter inactivated poliovirus without causing separation of the viral components. These results indicate that the release of RNA from the capsids is the result, not the cause, of virus inactivation by chlorine.  相似文献   
59.
Summary Chamaedorea bartlingiana is a dioecious palm that grows in the cloud forest understories of the Venezuelan Andes. Age and sexual differences in phenology and reproductive patterns were studied in labelled individuals of all age categories. This species has long-lived leaves and low leaf production, both characteristic of understory plants. Growth rates are lower in juveniles than in adults and in females than in males, as in other palms. Male and female individuals show different reproductive patterns. Male inflorescences are always produced at the same rate and the probability of surviving until anthesis is constant. Females produce reproductive buds at the same rate as males, but these buds have a 35% probability of becoming a ripe infrutescence if the plant has infrutescences already growing, and 70% if it does not. This pattern and the slow growth of inflorescences (1 year for males from bud to flowers, 2 years for females from bud to ripe fruits) cause a pluriannual reproductive pattern at the population level. Field germination does not follow this pattern, but shows one annual peak probably related to environmental conditions.  相似文献   
60.
A new method is proposed for the microtitration of CBPP vaccines by performing eight parallel endpoint two-fold dilutions. When performed on a 96-well plate, it gives a titre with a precision of +/- 0.2 log10. By comparison, the established method, performed in tubes, gives a precision of only +/- 0.6 log10. The adaptation to microtitre plates allows much more economical culture of larger numbers of samples. Statistical analysis permits determination of vial-to-vial homogeneity of a batch and calculation of a titre with a precision of +/- 0.09 log10. The new method may be applied for the titration of mycoplasmas.  相似文献   
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