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41.
Caveolae are membrane microdomains enriched in cholesterol, ganglioside M1 (GM1) and caveolin-1. We explored whether caveolae facilitate the entry of Leishmania chagasi into murine macrophages. Transient depletion of macrophage membrane cholesterol by 1 h exposure to methyl-beta-cyclodextrin (MbetaCD) impaired the phagocytosis of non-opsonized and serum-opsonized virulent L. chagasi. In contrast, MbetaCD did not affect the phagocytosis of opsonized attenuated L. chagasi. As early as 5 min after phagocytosis, virulent L. chagasi colocalized with the caveolae markers GM1 and caveolin-1, and colocalization continued for over 48 h. We explored the kinetics of lysosome fusion. Whereas fluorescent-labelled dextran entered macrophage lysosomes by 30 min after addition, localization of L. chagasi in lysosomes was delayed for 24-48 h after phagocytosis. However, after transient depletion of cholesterol from macrophage membrane with MbetaCD, the proportion of L. chagasi-containing phagosomes that fused with lysosomes increased significantly. Furthermore, intracellular replication was impaired in parasites entering after transient cholesterol depletion, even though lipid microdomains were restored by 4 h after treatment. These observations suggest that virulent L. chagasi localize in caveolae during phagocytosis by host macrophages, and that cholesterol-containing macrophage membrane domains, such as caveolae, target parasites to a pathway that promotes delay of lysosome fusion and intracellular survival. 相似文献
42.
Bebbington D Dawson CE Gaur S Spencer J 《Bioorganic & medicinal chemistry letters》2002,12(22):3297-3300
Water soluble prodrugs of hybrid free radical scavenger/iron chelating molecules, based on 3,5-disubstituted-4-hydroxyphenyl derivatives and 3-hydroxy-2-methyl-4(1H)-pyridinone (deferiprone), have been prepared. Related hybrid molecules containing a covalent poly(ethylene)glycol or an amine linker were also synthesized. 相似文献
43.
This article examines the influence of nutritional status on the emergence of deciduous dentition in a cross-sectional sample of 510 rural Rajput children from the Jubbal and Kotkhai Tehsils, Shimla District, Himachal Pradesh, India. The nutritional status of each child was evaluated using Z-scores of height/supine length-for-age (HAZ), weight-for-age (WAZ), and weight-for-height (WHZ). The effects of sex and side on deciduous dental emergence were not statistically significant. Partial correlation indicates that the number of emerged teeth (T) was more strongly correlated with height than with other anthropometric variables. In most age groups, the stunted boys and girls (HAZ <-2) had fewer emerged teeth than nonstunted age peers (HAZ >-2). The mean T in underweight children was also less than that of the normal children, with a few exceptions. The stunted children have a significantly greater likelihood of delayed emergence of deciduous dentition. Measures of linear growth status are more closely related to dental development than measures of growth in mass. The findings indicate that even moderate undernutrition can delay deciduous tooth emergence. 相似文献
44.
The chickpea (Cicer arietinum L.) is a self-pollinated grain legume with cleistogamous flowers. A spontaneous open-flower mutant, designated OFM-3, was identified in which reproductive organs were not enclosed by the keel petals and thus remained exposed. All 10 stamens in this mutant were free, whereas these are in diadelphous (9 fused + 1 free) condition in normal chickpea flowers. A large number of pods (73%) remained unfilled (empty) in OFM-3, though its pollen fertility was as high as the standard cultivars. The open-flower trait was found to be recessive and controlled by a single gene. OFM-3 was crossed with earlier reported open-flower mutants, ICC 16341 and ICC 16129, to establish trait relationships of genes controlling open flower traits in these mutants. It was found that each of these mutants has a unique gene for open flower trait. The genes controlling open flower trait in ICC 16341, ICC 16129, and OFM-3 were designated ofl-1, ofl-2, and ofl-3, respectively. Breeding lines with open flower trait and higher percentage of filled pods have been developed from the progenies of the crosses of OFM-3 with normal-flowered lines. The open flower trait offers opportunity for exploring hybrid technology in the chickpea. 相似文献
45.
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47.
Choudhary S Gaur R Gupta S 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(8):1449-1462
Well-saturated linkage maps especially those based on expressed sequence tag (EST)-derived genic molecular markers (GMMs)
are a pre-requisite for molecular breeding. This is especially true in important legumes such as chickpea where few simple
sequence repeats (SSR) and even fewer GMM-based maps have been developed. Therefore, in this study, 2,496 ESTs were generated
from chickpea seeds and utilized for the development of 487 novel EST-derived functional markers which included 125 EST-SSRs,
151 intron targeted primers (ITPs), 109 expressed sequence tag polymorphisms (ESTPs), and 102 single nucleotide polymorphisms
(SNPs). Whereas EST-SSRs, ITPs, and ESTPs were developed by in silico analysis of the developed EST sequences, SNPs were identified
by allele resequencing and their genotyping was performed using the Illumina GoldenGate Assay. Parental polymorphism was analyzed
between C. arietinum ICC4958 and C. reticulatum PI489777, parents of the reference chickpea mapping population, using a total of 872 markers: 487 new gene-based markers
developed in this study along with 385 previously published markers, of which 318 (36.5%) were found to be polymorphic and
were used for genotyping. The genotypic data were integrated with the previously published data of 108 markers and an advanced
linkage map was generated that contained 406 loci distributed on eight linkage groups that spanned 1,497.7 cM. The average
marker density was 3.68 cM and the average number of markers per LG was 50.8. Among the mapped markers, 303 new genomic locations
were defined that included 177 gene-based and 126 gSSRs (genomic SSRs) thereby producing the most advanced gene-rich map of
chickpea solely based on co-dominant markers. 相似文献
48.
It is known that folding a protein chain into a cubic lattice is an NP-complete problem. We consider a seemingly easier problem: given a three-dimensional (3D) fold of a protein chain (coordinates of its C(alpha) atoms), we want to find the closest lattice approximation of this fold. This problem has been studied under names such as "lattice approximation of a protein chain", "the protein chain fitting problem", and "building of protein lattice models". We show that this problem is NP-complete for the cubic lattice with side close to 3.8 A and coordinate root mean square deviation. 相似文献
49.
Pushpa Singh Archna Suman Priyanka Tiwari Namita Arya Asha Gaur A. K. Shrivastava 《World journal of microbiology & biotechnology》2008,24(5):667-673
Pretreatment of lignocellulosic biomasses, the first step in their conversion to utilizable molecules requires very high energy
(steam and electricity), corrosion resistant high-pressure reactors and high temperatures. These severe conditions not only
add to the cost component of the entire process but also lead to the loss of sugars to the side reactions. Microbial pretreatments
have been reported to be associated with reducing the cost factors as well as the severities of the reactions. Eight bioagents,
including fungi and bacteria, were screened for their pretreatment effects on sugarcane trash. They narrowed down the C:N
ratio of trash from 108:1 to a varying range of approximately 42:1 to 60:1.The maximum drop in C:N ratio of 61% was observed
using Aspergillus terreus followed by Cellulomonas uda (52%) and Trichoderma reesei and Zymomonas mobilis (49%). The bioagents helped in degradation of sugarcane trash by production of cellulases, the maximum being produced by
A. terreus, (12 fold) followed by C. uda (10 fold), Cellulomonas cartae (9 fold) and Bacillus macerans (8 fold). The microbial pretreatment of trash rendered the easy accessibility of sugars for enzymatic hydrolysis, which can be directed
for production of alcohol. 相似文献
50.
Summary Xylanase from Scytalidium thermophilum was immobilized on Eudragit L-100, a pH sensitive copolymer of methacrylic acid and methyl methacrylate. The enzyme was non-covalently
immobilized and the system expressed 70% xylanase activity. The immobilized preparation had broader optimum temperature of
activity between 55 and 65 °C as compared to 65 °C in case of free enzyme and broader optimum pH between 6.0 and 7.0 as compared
to 6.5 in case of free enzyme. Immobilization increased the t1/2 of enzyme at 60 °C from 15 to 30 min with a stabilization factor of 2. The Km and Vmax values for the immobilized and free xylanase were 0.5% xylan and 0.89 μmol/ml/min and 0.35% xylan and 1.01 μmol/ml/min respectively. An Arrhenius plot showed an increased value of activation energy for immobilized xylanase (227 kcal/mol)
as compared to free xylanase (210 kcal/mol) confirming the higher temperature stability of the free enzyme. Enzymatic saccharification
of xylan was also improved by xylanase immobilization. 相似文献