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991.
Gioconda San-Blas Françoise Sorais Gustavo Niño-Vega Cioly Méndez Felipe San-Blas 《Current microbiology》1998,37(2):141-143
Cytosolic proteinases were assayed in both morphological phases of Paracoccidioides brasiliensis. Preparations from the mycelial phase were more active in vitro than those from the yeast cells. Optimal proteinase activities
for both phases occurred at pH's between 6.0 and 9.0, and at 45°C. Gelatin-SDS-PAGE electrophoresis separated several bands
(58–112 kDa) in mycelial preparations; a single band (70 kDa) was seen in yeast preparations. Enzymatic activities were inhibited
by antipain, phenyl methyl sulfonyl fluoride (PMSF), and chymostatin, suggestive of serine proteinases. Partial inhibition
of the mycelial enzymes by ethylene diamine tetraacetic acid (EDTA), 1,10-phenanthroline, and iodoacetamide, also suggested
the presence of cysteine- and metallo-proteinases. The enzymatic activity increased in preparations extracted from yeast cells
transforming to mycelia, and decreased in preparations obtained from the reverse process.
Received: 29 September 1997 / Accepted: 19 February 1998 相似文献
992.
Michele Glinn Binhui Ni Robert P. Irwin S. W. Kelley Sui-Zhen Lin Steven M. Paul 《Journal of neurochemistry》1998,70(5):1850-1858
Abstract: Inorganic phosphate (Pi ) plays a vital role in intracellular energy metabolism. Its many effects include stimulation of glucose use, enhancement of high-energy phosphate concentrations, and modulation of cytosolic free [Ca2+ ]. Cultured fetal rat cortical neurons constitutively import Pi , and cytosolic levels positively correlate with [ATP], [NADPH], and energy charge. In the present study, we demonstrate that the concentration of intracellular Pi is an important determinant of acute neuronal survival after an excitotoxic or oxidative insult to cultured fetal rat cortical neurons. Extracellular Pi dose-dependently enhanced survival of cortical neurons after exposure to NMDA at early (≤6 h) time points after termination of the insult. Pi similarly increased neuronal survival after exposure to kainic acid or H2 O2 . Pi -exposed neurons had higher basal intracellular [Pi ], [ATP], and [GSH], and slightly lower cytosolic free [Ca2+ ], compared with Pi -deprived neurons. Pi -exposed neurons maintained increased [ATP] after exposure to NMDA and displayed reduced formation of reactive oxygen species after exposure to kainic acid or H2 O2 , compared with Pi -deprived neurons. These findings demonstrate that changes in extracellular and intracellular Pi can affect neuronal survival after excitotoxic or oxidative insults. 相似文献
993.
J. J. Ni P. Wu D. Senadhira N. Huang 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(8):1361-1369
The amplified fragment length polymorphism (AFLP) technique combined with selective genotyping was used to map quantitative
trait loci (QTLs) associated with tolerance for phosphorus (P) deficiency in rice. P deficiency tolerant cultivar IR20 was
crossed to IR55178-3B-9-3 (sensitive to P-deficiency) and 285 recombinant inbred lines (RILs) were produced by single-seed
descent. The RILs were phenotyped for the trait by growing them in P-sufficient (10.0 mg/l) and P-deficient (0.5 mg/l) nutrient
solution and determining their relative tillering ability at 28 days after seeding, and relative shoot dry weight and relative
root dry weight at 42 days after seeding. Forty two of each of the extreme RILs (sensitive and tolerant) and the parents were
subjected to AFLP analysis. A map consisting of 217 AFLP markers was constructed. Its length was 1371.8 cM with an average
interval size of 7.62 cM. To assign linkage groups to chromosomes, 30 AFLP and 26 RFLP markers distributed over the 12 chromosomes
were employed as anchor markers. Based on the constructed map, a major QTL for P-deficiency tolerance, designated PHO, was
located on chromosome 12 and confirmed by RFLP markers RG9 and RG241 on the same chromosome. Several minor QTLs were mapped
on chromosomes 1, 6, and 9.
Received: 21 April 1998 / Accepted: 9 June 1998 相似文献
994.
Ni S Woese CR Aldrich HC Boone DR 《International journal of systematic bacteriology》1994,44(2):357-359
A sequence analysis of the 16S rRNA of Methanolobus siciliae T4/M(T) (T = type strain) showed that this strain is closely related to members of the genus Methanosarcina, especially Methanosarcina acetivorans C2A(T). Methanolobus siciliae T4/M(T) and HI350 were morphologically more similar to members of the genus Methanosarcina than to members of the genus Methanolobus in that they both formed massive cell aggregates with pseudosarcinae. Thus, we propose that Methanolobus siciliae should be transferred to the genus Methanosarcina as Methanosarcina siciliae. 相似文献
995.
Li Shuang Ni Yuqing Li Chen Xiang Qunyan Zhao Yan Xu Hui Huang Wu Wang Yanjiao Wang Yi Zhan Junkun Liu Youshuo 《Journal of physiology and biochemistry》2023,79(1):83-105
Journal of Physiology and Biochemistry - Long noncoding RNAs (lncRNAs) are emerging regulators of vascular diseases, yet their role in diabetic vascular calcification/aging remains poorly... 相似文献
996.
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by immune abnormalities leading to multi-organ damage. The activation of autoreactive B cell differentiation will lead to the production of pathogenic autoantibodies, contributing to the development of SLE. However, the effects of Ophiopogonin D (OP-D) on B cell activation and autoantibody production as well as renal injury in the pathogenesis of SLE remain unclear. MRL/lpr mice, one of the most commonly used animal models of SLE, were intragastrically administered with 5 mg/kg/d OP-D at 17 weeks of age for 3 weeks. The survival rates of mice in each group were monitored for 6 weeks until 23 weeks of age. Proteinuria and serum creatinine levels were measured. Serum levels of immunoglobulin (Ig)G, IgM, and anti-dsDNA autoantibodies were detected by enzyme-linked immunosorbent assay. Numbers of CD19+ B cells in the blood, spleen and bone marrow and numbers of splenic germinal center (GC) B cells were calculated by using flow cytometry. OP-D treatment prolonged survival in MRL/lpr mice. OP-D treatment reduced proteinuria and serum creatinine levels as well as mitigated renal pathological alternation in MRL/lpr mice. Furthermore, serum levels of IgG, IgM, and anti-dsDNA autoantibodies were reduced by OP-D treatment. OP-D lessened not only CD19+ B cells in the spleen and bone marrow but also plasma cells that secreted anti-dsDNA autoantibodies, IgG and IgM in the spleen and bone marrow. OP-D ameliorated the progression of SLE by inhibiting the secretion of autoantibodies though reducing B cell numbers. 相似文献
997.
高频水稻原生质体植株再生 总被引:3,自引:0,他引:3
在过去的几年中水稻(Oryza sativa L.)的原生质体培养取得了较大进展。我们在此基础上对国内大面积推广的优良粳稻品种的原生质体进行了高频植株再生的实验,并对两种不同的培养方法——琼脂糖包埋法和看护培养法进行了初步的比较研究。 相似文献
998.
SnR31, snR32, and snR33: three novel, non-essential snRNAs from Saccharomyces cerevisiae. 总被引:6,自引:4,他引:2
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A G Balakin G S Schneider M S Corbett J Ni M J Fournier 《Nucleic acids research》1993,21(23):5391-5397
Genes for three novel yeast snRNAs have been identified and tested for essentiality. Partial sequence information was developed for RNA extracted from isolated nuclei and the respective gene sequences were discovered by screening a DNA sequence database. The three RNAs contain 222, 188 and 183 nucleotides and are designated snR31, snR32 and snR33, respectively. Each RNA is derived from a single copy gene. The SNR31 gene is adjacent to a gene for an unnamed protein associated with the cap-binding protein eIF-4E. The SNR32 gene is next to a gene for ribosomal protein L41 and the gene for SNR33 is on chromosome III, between two open reading frames with no known function. Genetic disruption analyses showed that none of the three snRNAs is required for growth. The new RNAs bring the number of non-spliceosomal snRNAs characterized thus far in S. cerevisiae to 14, of which only three are essential. 相似文献
999.
我们从分离核获得的颗粒状小鼠着丝粒富集部分的特性是用间接免疫荧光法,微管组织中心(MTOC)活性的测试,SDS-PAGE 及荧光标记原位杂交法进行研讨的。这部分中的多数颗粒是DNA 和动点蛋白质的复合物,并且显示具有MTOC 活性。从这部分提出的DNA 杂交于小鼠腹水癌细胞所有的染色体的初级缢痕处。从这部分的蛋白质中检出的动点蛋白质,其主要蛋白质的分子量是55及59 KD。以上事实说明,就如我们过去已报告过的,这一部分是核富含着丝粒的部分。 相似文献
1000.
Among the tetrahydroisoquinoline(THIQ) of natural products, a family of THIQ alkaloids has the characteristics of similar biosynthetic pathway. Such THIQ alkaloids family mainly include Renieramycins, Ecteinasicdins, Tetrazaomine, Lemonomycin, etc. Most of these natural compounds have strong antitumor activities, and its family member Ecteinasicdins743 (ET-743, Trabectedin) has been marketed in the European Union and the United States for the treatment of advanced soft tissue tumors and ovarian cancer. Because of the excellent biological activity and complex chemical structure of this kind of THIQ products, it has aroused great interest of biologists and chemists, and many synthetic chemists have paid considerable efforts to their total synthesis over the past decade. Based on this, the recent advances in the total synthesis of such THIQ alkaloids are reviewed. 相似文献