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121.
A novel vanadyl curcumin complex (VO(cur)2) has been synthesized and and its physicochemical properties characterized. Biological characterization included in vitro testing for anti-rheumatic activity in synoviocytes, angiogenesis inhibition in smooth muscle cells and anti-cancer potential in mouse lymphoma cells; as well as in vivo testing for hypoglycemic activity by oral gavage in streptozotocin (STZ)-diabetic rats. VO(cur)2 was more effective as an anti-cancer agent, compared to uncomplexed curcumin or vanadyl ion alone, was more than twice as effective as curcumin alone as an anti-arthritic agent, and was more than four times as effective as curcumin alone in inhibiting smooth muscle cell proliferation. In both acute and chronic screening tests, VO(cur)2 was ineffective as an insulin mimetic agent; however, it also proved to be exceptionally non-toxic, with no evidence of negative symptomatology during a month-long treatment period, at doses up to and including 2.0 mmol kg(-1) day(-1).  相似文献   
122.
At the onset of mitosis, the pericentriolar Golgi apparatus of mammalian cells is converted into small fragments, which are dispersed throughout the cytosol. The Golgi-associated protein GRASP65 is involved in this process. To address the role of GRASP65 in mitotic Golgi fragmentation, we depleted the protein from HeLa cells by RNAi. In the absence of GRASP65, the number of cisternae per Golgi stack is reduced without affecting the overall organization of Golgi membranes and protein transport. GRASP65-depleted cells entered mitosis, but accumulated in metaphase with condensed chromatin and multiple aberrant spindles and eventually died. Although Centrin2 and g-tubulin were detected in two of the spindle poles, the other spindle poles contained g-tubulin, but not Centrin2. Furthermore, we provide evidence that the expression of the C-terminus of GRASP65 interferes with entry of cells into mitosis. Our results suggest the requirement for GRASP65 in the regulation of spindle dynamics rather than a direct role in the stacking of Golgi cisternae. This novel function is in addition to the previously established negative role of GRASP65 at the G2/M transition, which is mediated by its C-terminus.  相似文献   
123.
In the presence of oligomycin, EGTA, and magnesium ions, the protonophore uncoupling activity of palmitate (V(Pal)) is determined as the ratio of the acceleration of respiration with palmitate to its concentration. Under these conditions, V(Pal) in liver mitochondria of one-month-old rats with the body weight of 50 g is 1.46-fold higher than in liver mitochondria of adult rats with the body weight of 250 g, whereas the uncoupling activity of FCCP does not depend on the age of the animals. The difference in V(Pal) is mainly due to its component insensitive to carboxyatractylate and glutamate (V(Ins)). This value is 2.9-fold higher in mitochondria of one-month-old rats than in those of adult rats. The protonophore activity of palmitate is similar in liver mitochondria of four-day-old and adult rats. In liver mitochondria of adult mammals (mouse, rat, guinea pig, rabbit), V(Pal) decreases with increase in the body weight of the animals. In double logarithmic coordinates, the dependence of the V(Pal) value on the body weight is linear with slope angle tangent of -0.18. The V(Pal) value is mainly contributed by its component V(Ins). In the presence of calcium ions, palmitate induces the nonspecific permeability of the inner membrane of liver mitochondria (pore opening). This Ca2+-dependent uncoupling effect of palmitate is less pronounced in mitochondria of one-month-old rats than in those of adult rats. In mitochondria of adult animals (mice, rats, and guinea pigs), the Ca2+-dependent uncoupling activity of palmitate is virtually the same. It is concluded that the protonophore uncoupling effect of palmitate in liver mitochondria of mammals, unlike its Ca2+-dependent effect, is associated with thermogenesis at rest and also with production of additional heat on cooling of the animals.  相似文献   
124.
Cellulase-free xylan-degrading enzyme preparations from Acrophialophora nainiana, Humicola grisea var. thermoidea and two Trichoderma harzianum strains were used as bleaching agents for Eucalyptus kraft pulp, prior to a chlorine dioxide and alkaline bleaching sequence. In comparison to the control sequence (performed without xylanase pretreatment), the sequence incorporating enzyme treatment was more effective. Removal of residual lignin was indicated by a reduction in kappa number. Overall, enzyme preparations from T. harzianum were marginally more effective in reducing pulp viscosity and chlorine chemical consumption and improving the brightness of the kraft pulp. However, the highest reduction in pulp viscosity was mediated by the xylanase preparation from A. nainiana. Xylanase pretreatment compares very favorably with that of chemical pulping. Journal of Industrial Microbiology & Biotechnology (2002) 28, 204–206 DOI: 10.1038/sj/jim/7000227 Received 27 April 2001/ Accepted in revised form 03 November 2001  相似文献   
125.
Cloning and gene map assignment of the Xiphophorus DNA ligase 1 gene   总被引:1,自引:0,他引:1  
Fishes represent the stem vertebrate condition and have maintained several gene arrangements common to mammalian genomes throughout the 450 Myr of divergence from a common ancestor. One such syntenic arrangement includes the GPI-PEPD enzyme association on Xiphophorus linkage group IV and human chromosome 19. Previously we assigned the Xiphophorus homologue of the human ERCC2 gene to linkage group U5 in tight association with the CKM locus. CKM is also tightly linked to the ERCC2 locus on human chromosome 19, leading to speculation that human chromosome 19 may have arisen by fusion of two ancestral linkage groups which have been maintained in fishes. To investigate this hypothesis further, we isolated and sequenced Xiphophorus fish genomic regions exhibiting considerable sequence similarity to the human DNA ligase 1 amino acid sequence. Comparison of the fish DNA ligase sequence with those of other species suggests several modes of amino acid conservation in this gene. A 2.2-kb restriction fragment containing part of an X. maculatus DNA ligase 1 exon was used in backcross hybrid mapping with 12 enzyme or RFLP loci. Significant linkage was observed between the nucleoside phosphorylase (NP2) and the DNA ligase (LIG1) loci on Xiphophorus linkage group VI. This assignment suggests that the association of four DNA repair-related genes on human chromosome 19 may be the result of chance chromosomal rearrangements.   相似文献   
126.
ABSTRACT. Thirty four taxa of heterotrophic protists (amoebae, flagellates and heliozoa) were encountered in cultures established from marine samples from Belize (Central America) and Tenerife (Canary Islands). Most species are flagellates drawn from the choanoflagellates, the cryptophyceans, the euglenids, the kinetoplastids, the bicosoecids, the chromulinids, the pedinellids and a variety of laxa of uncertain affinities (Protista incertae sedis). the identity of the thecate choanoflagellates Salpingoeca ringens Kent, 1880, and S. tuba Kent, 1880, is discussed, and four new species of heterotrophic protists are described: one new species of the amoeba genus Paulinella (Paulinella intermedia n. sp.) and three new species of the incertae sedis genus Luffisphaera Belcher & Swale, 1975 ( Luffisphaera bulbochaete n. sp.; L. longihastis n. sp.; L. turriformis n. sp.).  相似文献   
127.
128.
Evolution and phylogenetic utility of the period gene in Lepidoptera   总被引:6,自引:0,他引:6  
Evolution and phylogenetic utility of the period gene are explored through sequence analysis of a relatively conserved 909-bp fragment in 26 lepidopteran species. Taxa range from tribes to superfamilies, primarily within the putative clade Macrolepidotera plus near outgroups, and include both strongly established and problematic groupings. Their divergence dates probably range from the late Cretaceous through much of the Tertiary. Comparisons within the same set of closely related species show that amino acid substitutions in period occur 4.9 and 44 times as frequently as they do in two other nuclear genes--dopa decarboxylase and elongation factor-1 alpha, respectively. In contrast, rates of observed synonymous substitution are within 60% of each other for these three genes. Synonymous changes in period approach saturation by the family level, whereas nonsynonymous and amino acid divergences across the Macrolepidoptera are less than half the maximal values reported for this gene. Phylogenetic analyses of period strongly supported groupings at the family level and below. In contrast to previous analyses at this level with other nuclear genes, much of the information lies in nonsynonymous change. Relationships up to the superfamily level were recovered with decreasing effectiveness, and little, if any, signal was apparent regarding relationships among superfamilies. This could reflect rapid radiation of the superfamilies, however, rather than saturation in the period locus; thus, period, in combination with other genes, remains a plausible candidate for approaching the difficult problems of lepidopteran family and superfamily relationships.   相似文献   
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