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991.
992.
Viable cells of Saccharomyces cerevisiae 4484-24D-1 mutant strain were treated with an Arthrobacter sp. beta-1,3-glucanase, Zymolyase-60,000, in the presence of a serine protease inhibitor, phenylmethylsulfonyl fluoride. Fractionation of the solubilized materials with Cetavlon (cetyltrimethylammonium bromide) yielded a purified mannan-protein complex, which had a molecular weight of ca. 150,000, approximately three times higher than that of the mannan isolated from the same cells by the hot-water extraction method at 135 C. The amino acid composition of the mannan-protein complex was found to be very similar to that of the mannan-protein complexes of S. cerevisiae X2180-1A wild and S. cerevisiae X2180-1A-5 mutant strains, indicating the presence of large amounts of serine and threonine. It was unexpected that the antibody-precipitating activity of this complex against the homologous anti-whole cell serum was about twice as great as that of the mannan isolated by hot-water extraction. Treatment of this complex with 100 mM NaOH, hot water at 135 C, and pronase, respectively, gave degradation products having the same molecular weight and antibody-precipitating activity as those of the hot-water extracted mannan, allowing the assumption that the protein moiety participated in a large part of this activity.  相似文献   
993.
The changes in the relative weight, cell area and ultrastructure of the submaxillary glands (SMG) of CBA/C57BL mice and those in the content of immunoreactive insulin-like protein (IRILP) occurring in the organ were studied. The changes were examined on day 6 after isoproterenol (ISP) injection (23 mg/100 g bw) to healthy animals (group I), on day 13 after pancreatectomy and on day 6 after injection of the indicated dose of ISP (group II), and on day 13 after pancreatectomy without ISP injection (group III). Intact animals served as control. In all the three experimental groups, the ratio between the SMG weight and the total weight of animals showed a tendency towards increase. The highest increase was recorded in group II, where the weight of the SMG was 46.1% higher than the control value. In groups II and III, the area of acinar cells increased by 49.1 and 12.5%, respectively. The area of salivary tube granular ducts decreased by 12.6% in group II and slightly increased (by 4.7% much greater than in group III. Electron microscopy demonstrated that secretory activity of the granular duct cells was enhanced in all the three groups and that secretory extrusion occurred via the apocrine (in group II animals via the holocrine as well) cells. The radioimmunoassay data suggest that IRILP content in the SMG of controls and animals entering groups I-III was 685 +/- 50, 1125 +/- 125, 914 +/- 120 and 302 +/- 66 mu units/g weight, respectively. It is concluded that the synthesis and accumulation of IRILP in the SMG after ISP injection are activated and that the formation and extrusion of IRILP after ISP injection to diabetic animals are overtly activated. Presumably ISP injection to diabetic mice facilitates the stimulation of the compensatory function of the SMG as an IRILP-producing organ.  相似文献   
994.
The brain of the lizard, Ctenosauria pectinata, was studied light microscopically using an immunocytochemical staining method that is specific for neurohypophysial hormones and somatostatin. It was shown that the telencephalon and particularly the diencephalon contain somatostatin-producing perikarya, while somatostatinergic fibers occur in the entire brain. Similar to the situation in other vertebrates, somatostatin neurons in Ctenosauria pectinata form a population distinct from the neurohypophysial hormone-producing neurons. The small-sized somatostatin neurons were found in the cortex and the diencephalon: (1) ventral from, and partially overlapping with, the classical neurosecretory paraventricular nucleus; and (2) in the region of the infundibular (tuberal) nucleus. Somatostatin fibers were found among the classical neurosecretory fibers of the supraoptico-paraventricular system (tract, median eminence, neural lobe), near to and within the epiphysis, in the septum, in the vicinity of the tectum opticum and the cerebellum, and in the tegmentum.  相似文献   
995.
Measurements have been made of the activities of enzymes of the pentose phosphate pathway, the glucuronate-xylulose pathway, hexokinase and phosphofructokinase in kidney of diabetic and normal rats. The activities of these enzymes keep pace with kidney growth, remaining constant per gram tissue but showing a marked increase on the basis of total activity per 100 g body wt. The formation of 14CO2 from [1-14C]glucose and [6-14C]glucose by kidney slices from diabetic rats was decreased to approximately half the control value; evidence was obtained for an equivalent dilution of the glucose 6-phosphate pool. Correction of the 14CO2 yields for the change in specific activity of glucose 6-phosphate yielded values consistent with the enzyme profile. Calculations from specific yields of 14CO2 provided evidence for an increased flux of glucose via the pentose phosphate pathway in the kidney in diabetes. The results are discussed in relation to kidney hypertrophy in diabetes and the requirement for ribose 5-phosphate and NADPH for biosynthetic reactions and in relation to the thickening of the basement membrane in diabetes. These results are in accord with the concept of glucose overutilization by non-insulin-requiring tissues.  相似文献   
996.
MIC-3 is a recently identified gene family shown to exhibit increased root-specific expression following nematode infection of cotton plants that are resistant to root-knot nematode. Here, we cloned and sequenced MIC-3 genes from selected diploid and tetraploid cotton species to reveal sequence differences at the molecular level and identify chromosomal locations of MIC-3 genes in Gossypium species. Detailed sequence analysis and phylogenetic clustering of MIC-3 genes indicated the presence of multiple MIC-3 gene members in Gossypium species. Haplotypes of a MIC-3 gene family member were discovered by comparative analysis among consensus sequences across genotypes within an individual clade in the phylogram to overcome the problem of duplicated loci in the tetraploid cotton. Deficiency tests of the SNPs delimited six At-genome members of the MIC-3 family clustered to chromosome arm 4sh, and one Dt-genome member to chromosome 19. Clustering was confirmed by long-PCR amplification of the intergenic regions using At-genome-specific MIC-3 primer pairs. The clustered distribution may have been favored by selection for responsiveness to evolving disease and/or pest pressures, because large variants of the MIC-3 gene family may have been recovered from small physical areas by recombination. This could give a buffer against selection pressure from a broad range of pest and pathogens in the future. To our knowledge, these are the first results on the evolution of clustering and genome-specific haplotype members of a unique cotton gene family associated with resistant response against a major pathogen.  相似文献   
997.
998.
Z N Zhuravleva 《Ontogenez》1987,18(4):369-379
Embryonic tissues of septum and hippocampus were transplanted into the anterior eye chamber (AEC) of adult rats. The morphology of initial embryonic tissues and of transplants within 3 to 4 months of cultivation in AEC was studied. The transplanted tissue consists of neuroblasts and immature neurones: no synaptic contacts are observed. Within 3 to 4 months, highly differentiated neurones establishing synaptic contacts can be seen in the transplants. At the same time the fine structure of perikaryons and dendrites undergoes some changes: increased vacuolization, transformation of ergastoplasm into lamellar bodies. These can be due to an elevated functional activity of some neurones. Another group of morphological abnormalities (increased number of dendrite processes and microphyllopodia, somatic spines, dendrite cones of growth, tight junctions between perikaryons) suggests incomplete tissue maturation. These might be due to the absence of normal afferent and trophic influences in AEC.  相似文献   
999.
About the role of protamine in transfection   总被引:1,自引:0,他引:1  
  相似文献   
1000.
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