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1.
A study was made of the radioprotective effect of polyanion, a co-polymer of maleic and methacrylic acids, administered separately and in a combination with adeturon to irradiated (8 Gy, LD100/18) H male mice. Adeturon (300 mg/kg) was injected 15 min before, and polyanion (4 mg/kg) 24 h after gamma-irradiation. The effect of the preparations was assessed by the survival rate and hematologic indices (for instance, weight and cellularity of the spleen, bone marrow cellularity, and the number of leukocytes) at defined intervals within 30 days. Adeturon exerted a pronounced protective effect on the haemopoietic system of lethally exposed mice. The therapeutic effect of polyanion applied in a combination with adeturon was not enhanced and did not modify the effect of the latter.  相似文献   

2.
There was an increase in the time of the implanted tumor doubling in size and in the life-span of animals treated with a combination of S-2-aminoethyl- isothiuronium ( adeturon ) and gamma-radiation as compared to those exposed to gamma-radiation alone.  相似文献   

3.
A study was made of the effect of four types of S-omega-carboxamidinoalkyl isothiourea, differing in the carbon chain length between amidine and isothiuronium groups, and adeturon on activity of lactate dehydrogenase (LDG) and its isoenzymes in blood serum and organs of rats. Adeturon and compounds with one and three methylene groups elicit a radioprotective effect whereas substances with an even number of methylene groups have no such an effect. The obtained data indicate that changes in activity of LDG and its isoenzymes depend upon the structure of the substance applied. This makes LDG an adequate model in comparative studying the specificity of biochemical effects induced by the radioprotective agents and substances similar in their structure but having no radioprotective efficiency.  相似文献   

4.
The number of populations of antibodies differing in their affinity for insulin was determined in guinea pig antiserum. The antibody fractions differing in their affinity were obtained by affinity chromatography on an antigenic sorbent. Elution with a stepwise pH gradient from 4 to 2 differing in the number and form of the steps resulted in 10 fractions of antibodies obtained from individual animal sera. The binding constants of fractionated antibodies were determined by a bioluminescent immunocofactor method. With a change in elution pH from 4 to 2, the equilibrious binding constant of antibodies increased from 10(6) to 5 X 10(9) M-1.  相似文献   

5.
Variety registration of lucerne often fails because of the difficulty to pass the distinction test. This test is presently based on phenotypic traits. We proposed to evaluate if high-throughput genotyping of varieties with genotyping-by-sequencing markers could help to distinguish among 20 varieties and if the genetic distances were correlated to phenotypic ones. Genotyping was performed either on 40 individuals or on 4 bulks of 100 plants per variety. At the methodological level, we obtained a high number of polymorphic markers, a precise determination of the allele dosage on the individuals, a high reproducibility of allele frequency estimated on bulks and a good correlation between allele frequencies scored on individuals or on bulks. Each pair of the 20 varieties was significantly distinct when using the markers. In addition, the varieties grouped in a way that was consistent with their genetic origin. Genetic distances were correlated to phenotypic distances obtained from data collected in the distinction tests. We suggest that molecular markers could be useful to assist distinction tests during the official trials for registration of lucerne varieties.  相似文献   

6.
The study of human evolution has always been a major issue in physical anthropology. Since computers became available this study became a new dimension in that it became feasible to apply advanced mathematical multivariate methods which make use of morphometric data. However, looking back on what has been achieved so far with these methods, it must be admitted that the results obtained are often unsatisfactory. This has led to a certain lack of acceptance of these methods. In the present paper it is argued that very useful results may be obtained by applying more sophisticated multivariate methods which are specifically designed for the anthropological problems at issue. Three examples are given. The first deals with the controversy between "Creationism" on the one hand and "Evolutionism" on the other. Our results strongly support the Evolutionists' point of view. The second example deals with the reconstruction of human phylogeny. An investigation is discussed which has led to a startling new hypothesis concerning the evolution of man. The last example concerns a preliminary investigation of trends in human sexual dimorphism. The results obtained so far seem to support the opinion expressed by other workers that tendencies exist in our modern society which lead to changes in the present dimorphism.  相似文献   

7.
The panel of monoclonal antibodies (MCA) ICO-16, ICO-17, ICO-18, ICO-19, ICO-20, ICO-27, ICO-28 IgG2a isotypes to CD38 antigen was obtained. MCA discovered the antigen with 45 kD molecular mass, expressed on the surface of 100% thymocytes, 43-53% lymphocytes, 32-46% monocytes. All obtained MCA blocked the binding each other with thymocyte of man. MCA reacts in complement-dependent cytotoxic test. The antigen CD38 is expressed on blast cells of patients with T-cells subset of ALL.  相似文献   

8.
Linkage of Familial Schizophrenia to Chromosome 13q32   总被引:7,自引:0,他引:7       下载免费PDF全文
Over the past 4 years, a number of investigators have reported findings suggestive of linkage to schizophrenia, with markers on chromosomes 13q32 and 8p21, with one recent study by Blouin et al. reporting significant linkage to these regions. As part of an ongoing genome scan, we evaluated microsatellite markers spanning chromosomes 8 and 13, for linkage to schizophrenia, in 21 extended Canadian families. Families were analyzed under autosomal dominant and recessive models, with broad and narrow definitions of schizophrenia. All models produced positive LOD scores with markers on 13q, with higher scores under the recessive models. The maximum three-point LOD scores were obtained under the recessive-broad model: 3.92 at recombination fraction (theta).1 with D13S793, under homogeneity, and 4.42 with alpha=.65 and straight theta=0 with D13S793, under heterogeneity. Positive LOD scores were also obtained, under all models, for markers on 8p. Although a maximum two-point LOD score of 3.49 was obtained under the dominant-narrow model with D8S136 at straight theta=0.1, multipoint analysis with closely flanking markers reduced the maximum LOD score in this region to 2. 13. These results provide independent significant evidence of linkage of a schizophrenia-susceptibility locus to markers on 13q32 and support the presence of a second susceptibility locus on 8p21.  相似文献   

9.
Light-dependent trans to cis isomerization of the retinal in halorhodopsin   总被引:2,自引:0,他引:2  
J K Lanyi 《FEBS letters》1984,175(2):337-342
Flash-induced absorption changes in the near UV were determined for bacteriorhodopsin and halorhodopsin on a millisecond time scale. The difference spectrum obtained for bacteriorhodopsin was comparable to model difference spectra of tyrosine (aromatic OH deprotonated vs protonated), as found by others. The flash-induced difference spectrum for halorhodopsin, in contrast, resembled a model spectrum obtained for trans to 13-cis isomerization of retinal in bacteriorhodopsin. A model for chloride translocation by halorhodopsin is presented, in which the retinal isomerization moves positive charges, which in turn modulate the affinity of a site to chloride.  相似文献   

10.
A decision rule is obtained to determine when exercise is beneficial. The term beneficial used in this context refers to the extension of lifetime based on studies of cardiovascular conditioning. Models are used to characterize changes in heart rate with intense exercise. In addition, it is necessary to consider a model involving a heartbeat bank to help determine the conditioning interval. Optimization procedures are used to develop the decision rule, to examine the assumptions in the problem, and to point out when a unique solution exists. This procedure is applied to empirical data for one individual (inter-subject study) and a unique conditioning interval is obtained.  相似文献   

11.
Xing R  Liu S  Yu H  Guo Z  Wang P  Li C  Li Z  Li P 《Carbohydrate research》2005,340(13):2150-2153
The effect of inorganic salts such as sodium chloride on the hydrolysis of chitosan in a microwave field was investigated. While it is known that microwave heating is a convenient way to obtain a wide range of products of different molecular weights only by changing the reaction time and/or the radiation power, the addition of some inorganic salts was shown to effectively accelerate the degradation of chitosan under microwave irradiation. The molecular weight of the degraded chitosan obtained by microwave irradiation was considerably lower than that obtained by traditional heating. Moreover, the molecular weight of degraded chitosan obtained by microwave irradiation assisted under the conditions of added salt was considerably lower than that obtained by microwave irradiation without added salt. Furthermore, the effect of ionic strength of the added salts was not linked with the change of molecular weight. FTIR spectral analyses demonstrated that a significantly shorter time was required to obtain a satisfactory molecular weight by the microwave irradiation-assisted inorganic salt method than by microwave irradiation without inorganic salts and conventional technology.  相似文献   

12.
A constrained regularization procedure has been applied to a low-angle quasi-elastic light scattering system in order to determine particle size distributions. The conditions under which this procedure may be successfully applied to low-angle photon correlation spectroscopy have been characterized. Acquisition of photon count data over a short time period, relative to the long exponential decay constants of correlation functions obtained at low forward angles, resulted in particle size distributions which were stable with regard to peak width and weighted mean particle radius. Irrespective of the number of photon counts obtained, peak resolution and position on the particle size scale were not optimized unless anomalies in the correlation function due to transient increases in the mean photon counting rate were removed from the photon count data prior to autocorrelation. When such measures were taken, reasonable size distributions were obtained for well characterized protein standards and for liposomal suspensions.  相似文献   

13.
The protoplast fusion of Aspergillus sojae was studied to develop a breeding system for the more desirable koji- molds in the production of shoyu (Japanese fermented soy-sauce) with special attention as to their enzyme productivities. Double-marker mutants, as to conidial color and nutritional requirement, were first derived from the parental strains selected from genealogically unrelated A. sojae cultures showing characteristic enzyme-productivities. Protoplasts of the mutants were obtained in high yields by using a combined enzyme-system composed of the enzyme preparation obtained from a culture filtrate of Bacillus circulans I AM 1165 and commercial chitinase (ICN). The protoplasts were fused in PEG 6000. Many of the fused products that grew on minimal regeneration plates were found to be heterokaryons. Stable heterozygous diploids with green conidia were induced from heterokaryons on UV treatment. One hundred and thirty diploid strains were obtained and their enzyme-productivities were assayed. The activities of both protease and glutaminase were distributed within the range of those of the parents, and in most strains, the sum of the two activities did not exceed those in the cases of the parents. Exceptionally, a few diploids showing well-balanced high productivity of both enzymes were also obtained.  相似文献   

14.
β-Amylase (EC 3.2.1.2), obtained from barley, was chemically attached to a crosslinked copolymer of acrylamide-acrylic acid using a water-soluble carbodiimide. The derivative showed 23% β-amylase activity in relation to that of free enzyme with a coupling yield of 40% based on the amount of added β-amylase. In order to find optimal coupling conditions, the effect of pH and different carbodiimide concentrations was investigated. The enzymic activity associated with different β-amylase concentrations was further outlined. A slightly increased operational stability for the enzyme upon immobilization was observed. Markedly improved operational stability has been obtained by coupling in the presence of reduced glutathione of bovine serum albumin.  相似文献   

15.
The influence of different fructose concentrations (5, 3, 1 and 0 g/l) was tested on Germ Tube (GT) production by Candida albicans strain AS3P, using a Minimal Synthetic Medium (MSM) without (NH4)2SO4. The results obtained showed good GT production in the presence of all the different fructose concentrations and in the absence of any nitrogen source. The greatest GT production was obtained with 3 g/l of fructose vs 1 g/l of glucose, after 4 hr of incubation. On the other hand fructose consumption was lower than that of glucose at all concentrations over the 4 hour period. The data obtained may suggest that fructose is metabolized in a different way from glucose for GT production by C. albicans.  相似文献   

16.
This paper introduces an indicator system to evaluate sustainability in established coastal tourism destinations, applying the recommendations and definitions of the World Tourism Organization (WTO). We also develop a new synthetic indicator to simplify the measurement of sustainability and facilitate the comparative analysis of destination ranking. This measurement was obtained by applying a procedure to reduce the number of subjective decisions made by the analyst, using a novel two-stage aggregation methodology based on principal component analysis and on the distance to a reference point. The synthetic indicator obtained was applied to Spanish coastal destinations, and the results serve as a guideline for tourism planning. The conclusions of this research can be extrapolated to the study of other tourism destinations.  相似文献   

17.
A sarcolysine-resistant strain of mouse plasmacytoma MOPC/406 was obtained in experiments on 250 BALB/c mice. The initial plasmacytoma strain is highly sensitive to sarcolysine. When administered in doses of 10 and 5 mg/kg it increases the lifespan up to 50 days (the observation period). In the course of resistance induction by incremental doses of sarcolysine, a highly resistant plasmacytoma strain was obtained. In the 20th generation of inoculations with the use of sarcolysine administration of 10 mg/kg (intraperitoneally) provided only a 18% increase in the lifespan, whereas the dose 5 mg/kg stimulated the growth of plasmacytoma. The strain obtained preserves its resistance under cryoconservation in liquid nitrogen, being a model that permits one to study resistance, cross-resistance and approaches to its overcoming.  相似文献   

18.
A microtechnique has been developed and adapted successfully to the microscopic agglutination test with live antigens for detection of leptospiral antibodies. Simultaneous titrations were performed by the conventional microscopic agglutination test and the microtechnique. When the microtechnique was used to screen 50 unknown leptospiral strains with a battery of hyperimmune sera, 98% agreement was obtained with the conventional procedure. Comparative data on 635 tests on these 50 cultures established the reliability of the microtechnique. Results with the two tests on 46 human sera revealed 93% agreement in the detection of leptospiral antibodies. The validity and reliability of the microtechnique obtained in these comparative studies suggests that it can be used as a valuable screening procedure for the microscopic agglutination test for preliminary cross agglutination studies on unknown strains and for the detection of leptospiral antibodies in human and animal sera.  相似文献   

19.
20.
Time courses for inhibition of carnitine palmitoyltransferase (CPT) I activity in, and [14C]malonyl-CoA binding to, liver mitochondria from fed or 48 h-starved rats were obtained at 37 degrees C by using identical incubation conditions and a fixed concentration of malonyl-CoA (3.5 microM), which represents the middle of the physiological range observed previously [Zammit (1981) Biochem. J. 198, 75-83] Incubation of mitochondria in the absence of malonyl-CoA resulted in a time-dependent decrease in the ability of the metabolite instantaneously to inhibit CPT I and to bind to the mitochondria. Both degree of inhibition and binding were restored in parallel over a period of 6-8 min on subsequent addition of malonyl-CoA to the incubation medium. However, the increased inhibition of CPT I activity on addition of mitochondria directly to malonyl-CoA-containing medium was not accompanied by an increase in the amount of [14C]malonyl-CoA bound to mitochondria at 37 degrees C. Time courses for binding of [14C]malonyl-CoA performed at 0 degree C were different from those obtained at 37 degrees C. There was little loss of ability of [14C]malonyl-CoA to bind to mitochondria on incubation in the absence of the metabolite, but there was a time-dependent increase in binding on addition of mitochondria to malonyl-CoA-containing medium. It is suggested that these temperature-dependent differences between the time courses obtained may be due to the occurrence of different changes at 37 degrees C and at 0 degree C in the relative contributions of different components (with different affinities) to the binding observed at 3.5 microM-malonyl-CoA. Evidence for multi-component binding was obtained in the form of strongly curvilinear Scatchard plots for instantaneous (5s) binding of malonyl-CoA to mitochondria. Such multi-component binding would be expected from previous results on the different affinities of CPT I for malonyl-CoA with respect to inhibition [Zammit (1984) Biochem. J. 218, 379-386]. Mitochondria obtained from starved rats showed qualitatively the same time courses as those described above, with notable quantitative differences with respect both to the absolute extents of CPT I inhibition and [14C]malonyl-CoA binding achieved as well as to the time taken to attain them.  相似文献   

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