排序方式: 共有78条查询结果,搜索用时 15 毫秒
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Dominik Thimm Melanie Knospe Aliaa Abdelrahman Miguel Moutinho Bernt B. A. Alsdorf Ivar von Kügelgen Anke C. Schiedel Christa E. Müller 《Purinergic signalling》2013,9(3):415-426
The nucleobase adenine has previously been reported to activate G protein-coupled receptors in rat and mouse. Adenine receptors (AdeR) thus constitute a new family of purine receptors, for which the designation “P0-receptors” has been suggested. We now describe the cloning and characterization of two new members of the AdeR family from mouse (MrgA10, termed mAde1R) and hamster (cAdeR). Both receptors were expressed in Sf9 insect cells, and radioligand binding studies were performed using [3H]adenine. Specific binding of the radioligand was detected in transfected, but not in untransfected cells, and K D values of 286 nM (mAde1R, B max 1.18 pmol/mg protein) and 301 nM (cAdeR, B max 17.7 pmol/mg protein), respectively, were determined. A series of adenine derivatives was investigated in competition binding assays. Minor structural modifications generally led to a reduction or loss of affinity, with one exception: 2-fluoroadenine was at least as potent as adenine itself at the cAdeR. Structure–activity relationships at all AdeR orthologs and subtypes investigated so far were similar, but not identical. For functional analyses, the cAdeR was homologously expressed in Chinese hamster ovary (CHO) cells, while the mAde1R was heterologously expressed in 1321N1 astrocytoma cells. Like the previously described AdeRs from rat (rAdeR) and mouse (mAde2R), the mAde1R (EC50 9.77 nM) and the cAdeR (EC50 51.6 nM) were coupled to inhibition of adenylate cyclase. In addition, the cAdeR from hamster expressed in CHO cells produced an increase in intracellular calcium concentrations (EC50 6.24 nM) and was found to be additionally coupled to Gq proteins. 相似文献
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Chlamydia trachomatis utilizes the mammalian CLA1 lipid transporter to acquire host phosphatidylcholine essential for growth 下载免费PDF全文
John V. Cox Yasser M. Abdelrahman Jan Peters Nirun Naher Robert J. Belland 《Cellular microbiology》2016,18(3):305-318
Phosphatidylcholine is a constituent of Chlamydia trachomatis membranes that must be acquired from its mammalian host to support bacterial proliferation. The CLA1 (SR‐B1) receptor is a bi‐directional phosphatidylcholine/cholesterol transporter that is recruited to the inclusion of Chlamydia‐infected cells along with ABCA1. C. trachomatis growth was inhibited in a dose‐dependent manner by BLT‐1, a selective inhibitor of CLA1 function. Expression of a BLT‐1‐insensitive CLA1(C384S) mutant ameliorated the effect of the drug on chlamydial growth. CLA1 knockdown using shRNAs corroborated an important role for CLA1 in the growth of C. trachomatis. Trafficking of a fluorescent phosphatidylcholine analogue to Chlamydia was blocked by the inhibition of CLA1 or ABCA1 function, indicating a critical role for these transporters in phosphatidylcholine acquisition by this organism. Our analyses using a dual‐labelled fluorescent phosphatidylcholine analogue and mass spectrometry showed that the phosphatidylcholine associated with isolated Chlamydia was unmodified host phosphatidylcholine. These results indicate that C. trachomatis co‐opts host phospholipid transporters normally used to assemble lipoproteins to acquire host phosphatidylcholine essential for growth. 相似文献
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Yasmine Alaa El-Din Amal Hassan Abdelrahman Safa Fathy 《Biotechnic & histochemistry》2019,94(2):92-99
Salivary gland neoplasms exhibit complex histopathology in a variety of tumor types and treatment options depend largely on the stage of the cancer. Induced pluripotent stem cells (iPS) have been investigated for treating induced salivary gland cancer and for restoring salivary gland function. We investigated iPS treatment for salivary gland cancer both in vitro and in vivo. For our study in vitro, we re-programmed human skin fibroblasts to form iPS cells using a plasmid containing Oct4, Sox2, L-MYC and LIN28. For our study in vivo, we used 30 white male albino rats divided into the following groups of 10: group 1 (control): rats were injected with phosphate-buffered saline (PBS), group 2 induced squamous cell carcinoma (SCC): rat submandibular glands were injected with squamous carcinoma cells (SCC), group 3 (induced SCC/iPS): SCC treated rats treated with 5 × 106 iPS cells. Submandibular glands from rats of all groups were examined histologically and real time PCR was performed for amylase, and COX I and COX II gene expression. We confirmed that submandibular gland specimens included tumor tissue before starting treatment with iPS. iPS treated cases exhibited regeneration of salivary glands, although minor degenerative and vascularization changes remained. The acinar cells regained their proper organization, but continued to exhibit abnormal activity including hyperchromatism. iPS cells may be useful for treating salivary gland carcinomas. 相似文献
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Abdelrahman M. AlOkda Mostafa M. Nasr Shaimaa N. Amin 《Journal of cellular physiology》2019,234(5):5722-5727
Psychiatric disorders such as anxiety, phobias, and post-traumatic stress disorder are considered of high global prevalence. Currently, a therapeutic approach to treat these disorders using beta-blockers, which antagonize the beta-adrenergic receptors (B1, B2, and B3) is being studied. This approach claims that beta-blockers, such as propranolol, inhibit fear memory reconsolidation. However, there are several studies refuting such claims by discrediting their experimental design and pointing out both the drugs pharmacokinetic properties and confounding factors. In this review, we explore the different effects of central beta-adrenergic agonists and antagonists on the fear memory consolidation providing mixed-evidence, limitations, and future directions. 相似文献
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Serry FM Kadry AA Abdelrahman AA 《Journal of industrial microbiology & biotechnology》2003,30(3):135-140
The present study aimed to isolate, select, and evaluate bacterial isolates with potential for use as biological indicators
for sterilization with glutaraldehyde and/or formaldehyde. A total of 340 local Bacillus isolates were screened for glutaraldehyde and/or formaldehyde resistance by determination of minimum inhibitory concentrations
(MICs), minimum bactericidal concentrations (MBCs), and extinction time and were compared with B. subtilis (var. niger) ATCC 9372, the biological indicator for ethylene oxide sterilization, as reference. Of these, 85 isolates had glutaraldehyde
MICs of 0.5% or higher, while 29 had formaldehyde MICs of 0.04% or higher. Of the 29 resistant isolates, 15 had MBCs of 0.05%
or more. Extinction times were used to evaluate the bactericidal/sporicidal activity of glutaraldehyde. Eight had inactivation
times of more than 5 h in 2% glutaraldehyde (pH 8), whereas 12 had inactivation times of more than 3 h in l% formaldehyde,
with one isolate in common. These 19 isolates were selected and evaluated as potential biological indicators for aldehydes
by determination of the decimal reduction times (D values), compared with the reference strain. Eight glutaraldehyde-resistant isolates exhibited D values 2.0- to 3.5-fold higher than the reference strain (30 min.). Only five of 12 formaldehyde resistant isolates had D values higher than that of the reference strain. Using six resistant isolates, temperature coefficient values between 2.11 and
3.02 were obtained for 2% formaldehyde. Finally, 14 isolates were tested for potential pathogenicity and were identified to
species level. All of the eight glutaraldehyde-resistant isolates, including the isolate with dual resistance, and three formaldehyde-resistant
isolates were B. licheniformis, while two other formaldehyde-resistant isolates were B. cereus. Six of the selected B. licheniformis isolates are potential biological indicators for sterilization processes using aldehydes. Three can be suggested for glutaraldehyde
only and three for both aldehydes.
Electronic Publication 相似文献
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Rami Abdelrahman 《Reviews in Environmental Science and Biotechnology》2011,10(3):181-182
Stockholm Water Perspectives
2011 Stockholm water prize laureate highlights lake ecosystem dangers and opportunities 相似文献10.
Mohamed Elmarasi Ibrahim Elmakaty Basel Elsayed Abdelrahman Elsayed Jana Al Zein Ammar Boudaka Ali H. Eid 《Journal of cellular physiology》2024,239(4):e31200
Vascular smooth muscle cells (VSMCs) play a critical role in regulating vasotone, and their phenotypic plasticity is a key contributor to the pathogenesis of various vascular diseases. Two main VSMC phenotypes have been well described: contractile and synthetic. Contractile VSMCs are typically found in the tunica media of the vessel wall, and are responsible for regulating vascular tone and diameter. Synthetic VSMCs, on the other hand, are typically found in the tunica intima and adventitia, and are involved in vascular repair and remodeling. Switching between contractile and synthetic phenotypes occurs in response to various insults and stimuli, such as injury or inflammation, and this allows VSMCs to adapt to changing environmental cues and regulate vascular tone, growth, and repair. Furthermore, VSMCs can also switch to osteoblast-like and chondrocyte-like cell phenotypes, which may contribute to vascular calcification and other pathological processes like the formation of atherosclerotic plaques. This provides discusses the mechanisms that regulate VSMC phenotypic switching and its role in the development of vascular diseases. A better understanding of these processes is essential for the development of effective diagnostic and therapeutic strategies. 相似文献