排序方式: 共有90条查询结果,搜索用时 156 毫秒
71.
Gihan M. Tawfeek Hala S. Elwakil Nabil S. Awad Laila El-Hoseiny Hala S. Thabet Rania M. Sarhan Samar K. Darweesh Wagida A. Anwar 《The Korean journal of parasitology》2009,47(3):259-264
Genetic polymorphisms of encoding antigen B2 gene (AgB2) in Echinococcus granulosus were studied using PCR-RFLP and DNA sequencing among 20 Egyptian isolates. Five isolates from different host origins (humans, camels, pigs, and sheep) were collected and used. All examined isolates of each host group gave very similar patterns of PCR-RFLP after restriction enzyme digestion with AluI, with the gene size of approximately 140 bp and 240 bp for sheep and human isolates, and approximately 150 bp and 250 bp for pig and camel isolates. No digestion pattern was obtained after incubation of all studied isolates with EcoRI. These results reveal high intra-group homogeneity. DNA sequence analysis highlighted that human infecting strain showed 100% identity with respect to sheep infecting isolate, 96% and 99% with pig and camel infecting isolates, respectively. 相似文献
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73.
Gihan I. Tennekoon Yasuo Kishimoto Inderjit Singh GenIchiro Nonaka Jean-Marie Bourre 《Developmental biology》1980,79(1):149-158
The time of appearance and the rate of accumulation of specific myelin lipids and proteins were measured in the rat optic nerve during the period from birth to 18 days. The appearance of the activities of several enzymes involved in the synthesis of these lipids was also monitored. Correlation of these biochemical data with previously known morphological findings indicated that the “active” oligodendrocytes (detected between 5 and 15 days after birth) displayed maximal levels of synthesis of the components of myelin, and that these cells appeared to be responsible for the initial synthesis of myelin. Both young and mature oligodendrocytes showed limited capacity to synthesize these compounds. Furthermore, induction of the enzymes involved in the synthesis of myelin components appeared to take place in a simultaneous, rather than a sequential manner. 相似文献
74.
† Vinodh Narayanan †Benedetta Ripepi ‡Ethylin Wang Jabs §Anita Hawkins §Constance Griffin Gihan Tennekoon 《Journal of neurochemistry》1994,63(6):2010-2013
Abstract: The myelin P2 protein, a 14,800-Da cytosolic protein found primarily in peripheral nerves, belongs to a family of fatty acid binding proteins. Although it is similar in amino acid sequence and tertiary structure to fatty acid binding proteins found in the liver, adipocytes, and intestine, its expression is limited to the nervous system. It is detected only in myelin-producing cells of the central and peripheral nervous systems, i.e., the oligodendrocytes and Schwann cells, respectively. As part of a program to understand the regulation of expression of this gene, to determine its function in myelin-producing cells, and to study its role in peripheral nerve disease, we have isolated and characterized overlapping human genomic clones encoding the P2 protein. We report here on the partial structure of this gene, and on its localization within the genome. By using a panel of human-hamster somatic cell hybrids and by in situ hybridization, we have mapped the human P2 gene to segment q21 on the long arm of chromosome 8. This result identifies the myelin P2 gene as a candidate gene for autosomal recessive Charcot-Marie-Tooth disease type 4A. 相似文献
75.
Hosny Abdel Aziz Mohamed Sharaf Magdy Omar Ahmed Abou El-Yazied Nada Ibrahim AlJwaizea Shaimaa Ismail Mohamed M. A. Omar Khadiga Alharbi Amr Elkelish Moataz Tawfik 《Phyton》2023,92(4):1019-1036
Drought stress has become more common in recent years as a result of climate change impacts on the production
of banana crops and other fruit trees. The growth and productivity of Musa spp are severely impacted by the gradual degradation of water resources and the erratic distribution pattern of annual precipitation amount. The aim
of the work includes increased drought tolerance in light of water scarcity in the world as a result of the bananas’
being gluttonous for water needs. This investigation was carried out from 2019 to 2020 to study the effect of
potassium silicate on morphological growth and biochemical parameters of Musa acuminata L under drought
stress by PEG. As a result, drought stress reduced the morphological characteristics such as shoots number, shoot
length, roots number, and survival percentage and biochemical characteristics such as chlorophyll a, b, carotenoids, stomatal status, and RWC. While proline content increased in the leaf of M. acuminata L. Media complemented with K2SiO3 (2 to 6 mM) either individually or in combination with PEG led to an improvement in all
morphological and biochemical characteristics. The activities of CAT, POD, and PPO enzymes increased signifi-
cantly compared to control. Furthermore, the lowest PPO, CAT, and POD activity were achieved. Additionally,
K2SiO3 treatments under drought stress successfully enhanced the leaf stomatal behavior. Our results suggest that
K2SiO3 can help to maintain plant integrity in the tested cultivar under drought stress. 相似文献
76.
L. A. R. Sallam M. E. Osman A. A. Hamdy Gihan M. Zaghlol 《World journal of microbiology & biotechnology》2008,24(9):1643-1656
Rice bran sample (12 Kg) was extracted and rice bran oil (RBO ≅ 76.8 g) was saponified. The resulted unsaponifiable matter
of RBO (RBO unsap) was qualitatively and quantitatively estimated using different chromatographic analyses. RBO, produced
9.65% unsaponifiable matter with the following contents, cholesterol, 6.75%; stigmasterol, 3.4%; β. sitosterol, 10.23% and
campesterol, 4.2%, in addition to unknown phytosterols, hydrocarbons and waxes. Microbial transformation process started by
screening of 35 bacterial strains, locally isolated from rice bran, air and soil, using RBO unsap as a carbon and an energy
source to produce some pharmaceutically useful C18 and C19 steroids. Moraxella ovis was the most potent isolate for its highest capability to utilize RBO unsap and selectively degrade the phytosterols side-chain
producing androst-4-ene-3,17-dione (AD), androsta-1,4-diene-3,17-dione (ADD), testosterone (T) and estrone (E). The RBO unsap
was the best carbon and energy source. Maximum production of the desired products was observed in 36 h, pH 7 and at 30°C by
M. ovis. 相似文献
77.
Li Y Gonzalez MI Meinkoth JL Field J Kazanietz MG Tennekoon GI 《The Journal of biological chemistry》2003,278(11):9585-9591
Lysophosphatidic acid (LPA; 1-acyl-sn-glycerol-3-phosphate), an abundant constituent of serum, mediates multiple biological responses via G protein-coupled serpentine receptors. Schwann cells express the LPA receptors (Edg receptors), which, once activated, have the potential to signal through G(alphai) to activate p21(ras) and phosphatidylinositol 3-kinase, through G(alphaq) to activate phospholipase C, or through G(q12/13) to activate the Rho pathway. We found that the addition of serum or LPA to serum-starved Schwann cells rapidly (10 min) induced the appearance of actin stress fibers via a Rho-mediated pathway. Furthermore, LPA was able to rescue Schwann cells from apoptosis in a G(alphai)/phosphatidylinositol 3-kinase/MEK/MAPK-dependent manner. In addition, LPA increased the expression of myelin protein P(0) in Schwann cells in a Galpha(i)-independent manner but dependent on protein kinase C. By means of pharmacological and overexpression approaches, we found that the novel isozyme protein kinase Cdelta was required for myelin P(0) expression. Thus, the multiple effects of LPA in Schwann cells (actin reorganization, survival, and myelin gene expression) appear to be mediated through the different G protein-dependent pathways activated by the LPA receptor. 相似文献
78.
A general method for the preparation of substituted pyridazinopyrazolotriazines is reported. 3-Aminopyrazolo[3,4-d]pyridazine was diazotized and coupled with active methylene reagents to afford the tricyclic pyridazino[3',4':3,4]pyrazolo[5,1-c]-1,2,4-triazines with substituents such as methyl, phenyl, ethoxycarbonyl, acetyl or benzoyl, depending on the methylene reagent used. In addition several condensation reactions with hydrazines gave the corresponding acid hydrazide and/or hydrazones. Reactions of 3 with aromatic aldehydes afforded hydrazones. The products were screened for their antimicrobial activity against five microorganisms. 相似文献
79.
Pauline Loison Neveen A. Hosny Patrick Gervais Dominique Champion Marina K. Kuimova Jean-Marie Perrier-Cornet 《生物化学与生物物理学报:生物膜》2013
We utilize the fluorescent molecular rotor Bodipy-C12 to investigate the viscoelastic properties of hydrophobic layers of bacterial spores Bacillus subtilis. The molecular rotor shows a marked increase in fluorescence lifetime, from 0.3 to 4 ns, upon viscosity increase from 1 to 1500 cP and can be incorporated into the hydrophobic layers within the spores from dormant state through to germination. We use fluorescence lifetime imaging microscopy to visualize the viscosity inside different compartments of the bacterial spore in order to investigate the inner membrane and relate its compaction to the extreme resistance observed during exposure of spores to toxic chemicals. We demonstrate that the bacterial spores possess an inner membrane that is characterized by a very high viscosity, exceeding 1000 cP, where the lipid bilayer is likely in a gel state. We also show that this membrane evolves during germination to reach a viscosity value close to that of a vegetative cell membrane, ca. 600 cP. The present study demonstrates quantitative imaging of the microscopic viscosity in hydrophobic layers of bacterial spores Bacillus subtilis and shows the potential for further investigation of spore membranes under environmental stress. 相似文献
80.