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121.
Thingholm TE Larsen MR Ingrell CR Kassem M Jensen ON 《Journal of proteome research》2008,7(8):3304-3313
Phosphorylation of plasma membrane proteins frequently initiates signal transduction pathways or attenuate plasma membrane transport processes. Because of the low abundance and hydrophobic features of many plasma membrane proteins and the low stoichiometry of protein phosphorylation, studies of the plasma membrane phosphoproteome are challenging. We present an optimized analytical strategy for plasma membrane phosphoproteomics that combines efficient plasma membrane protein preparation with TiO(2)-based phosphopeptide enrichment and high-performance mass spectrometry for phosphopeptide sequencing. We used sucrose centrifugation in combination with sodium carbonate extraction to achieve efficient and reproducible purification of low microgram levels of plasma membrane proteins from human mesenchymal stem cells (hMSCs, 10(7) cells), achieving more than 70% yield of membrane proteins. Phosphopeptide enrichment by titanium dioxide chromatography followed by capillary liquid chromatography-tandem mass spectrometry allowed us to assign 703 unique phosphorylation sites in 376 phosphoproteins. Our experiments revealed that treatment of cell cultures with three different types of protein phosphatase inhibitors produces distinct phosphopeptide populations and an increase of 10-40% of the number of detected and sequenced phosphoserine, phosphothreonine and phosphotyrosine containing peptides. In summary, our analytical strategy enables functional phosphoproteomic analysis of stem cell differentiation and cell surface biomarker discovery using very low amounts of starting material. 相似文献
122.
Zahran MA Salem TA Samaka RM Agwa HS Awad AR 《Bioorganic & medicinal chemistry》2008,16(22):9708-9718
A series of 16 novel thalidomide sulfur analogs containing one and two sulfur atoms 2 and 4-18, respectively, were designed and synthesized. These compounds were screened for in vitro antitumor activity against Ehrlich ascites carcinoma (EAC) cell line and exhibited potent cytotoxic activity. On the bases of the obtained results for in vitro cytotoxic activity, thalidomide sulfur analogs containing two sulfur atoms 8, 9, 13 and 14 were selected and tested in vivo against EAC-induced solid tumor in female mice compared to thalidomide 1 as well as its analog 2 and exhibited a highly significant reduction in tumor volume (TV). Results illustrated the antioxidative activity of these compounds as the level of hepatic lipid peroxidation decreased and levels of antioxidant enzymes like superoxide dismutase (SOD) and catalase were elevated. The histopathological investigations revealed that thalidomide sulfur analogs 2, 8, 9, 13 and 14 have antimitotic, apoptotic and necrotic activities against solid tumor. These compounds lead to increase of Fas-L expression. The immunohistochemical studies showed a decrease in Ki67 and vascular endothelial growth factor (VEGF) staining in tumor cells from treated-animals when compared with non-treated groups, which suggests an inhibition of tumor proliferation rate and angiogenic process associated with tumor growth. Compounds 9 and 13 were the most potent compounds in tumor necrosis without liver necrosis. At the same time, treatment with compound 9 resulted in liver degeneration. 相似文献
123.
El Sayed H. El Ashry Ahmed A. Kassem Hamida M. Abdel-Hamid Farida Louis Mohamed R. Aouad 《Carbohydrate research》2009,344(6):725-733
The glycosylation of 5-(3-chlorobenzo[b]thien-2-yl)-4H-1,2,4-triazole-3-thiol (1) and its 3-benzylsulfanyl and 3-methylsulfanyl derivatives with different glycosyl halides 2-4 has been studied in presence of base. The S-glycosides 5-7 were obtained in the presence of triethylamine, whereas the respective S,N4-bis(glycosyl) derivatives 8-10 were synthesized in the presence of potassium carbonate; the S,N2-bis(glycosyl) isomer 11 could also be isolated in the case of the galactosyl analog. Similarly, after protecting 1 as 3-benzyl(methyl)sulfanyl derivatives 12 or 13, the N4-glycosyl analogs 14-19 as well as minor amounts of S,N2-bis(galactosyl) isomers 20 and 21 were formed. The theoretical calculations using AM1 semiempirical methods agreed with the experimental results. Microwave irradiation (MWI) led to higher yields in much less time than the conventional methods, and no change in regioselectivity has been noticed. 相似文献
124.
Amal M. Mohamed Tarek F. Elwakil Ibrahim M. Taher Mohamed M. Elbarbary Hesham F. Kayed Hassan A. Hussein Ola M. Eid 《Cell and tissue research》2009,338(1):107-115
Cyclin D1 gene amplification has been reported to promote abnormal endothelial cell proliferation and angiogenesis; these
findings constantly present in proliferating haemangiomas. The present study was conducted to evaluate cyclin D1 gene amplification
by fluorescence in situ hybridization analysis in tissue biopsies of 22 proliferating haemangiomas from 20 infants. Two significant
correlations of cyclin D1 gene amplification with the early onset and the duplication of proliferating haemangiomas have been
observed. Moreover, a significant correlation (P≤0.05) has been found between the treatment parameters of proliferating haemangiomas with the amplified versus the normal
cyclin D1 gene. Proliferating haemangiomas with the amplified cyclin D1 gene required more frequent flashlamp pulsed dye laser
treatment sessions at the maximum dosimetry and more frequent intralesional steroid injections at the maximum dose/injection
but treatment outcomes were limited. The more frequent post-treatment complications among proliferating haemangiomas with
cyclin D1 gene amplification might be attributable not only to the associated more aggressive natural course, but also to
the higher treatment parameters needed for effective treatment. Within the limitations of the present study, cyclin D1 gene
amplification was seen for the first time in proliferating haemangiomas. We have found that the amplification of the cyclin
D1 gene can predict the more aggressive natural course of proliferating haemangiomas and the limited outcome and higher incidence
of complications after non–excision treatment modalities. The present findings reflect the possible usefulness of antisense
cyclin D1 to improve the therapeutic outcome of proliferating haemangiomas. 相似文献
125.
126.
Amjad I. A. Hussein Ashraf M. Ahmed Maiko Sato Tadashi Shimamoto 《Microbiology and immunology》2009,53(11):595-602
Sixty Gram-negative bacterial isolates were collected from Palestinian hospitals in 2006. Thirty-two (53.3%) isolates showed multidrug resistance phenotypes. PCR and DNA sequencing were used to characterize integrons and antimicrobial resistance genes. PCR screening showed that 19 (31.7%) and five (8.3%) isolates were positive for class 1 and class 2 integrons, respectively. DNA-sequencing results for the captured antimicrobial resistance gene cassettes within class 1 integrons identified the following genes: dihydrofolate reductases, dfrA1 , dfrA5 , dfrA7 , dfrA12, dfrA17 and dfrA25 ; aminoglycoside adenyltransferases, aadA1, aadA2 , aadA5, aadA12 and aadB ; aminoglycoside acetyltransferase, aac(6')-Ib ; and chloramphenicol resistance gene, cmlA1 . ESBL were identified in 25 (41.7%) isolates. The identified ESBL were bla CTX-M-15 , bla CTX-M-56 , bla OXA-1 , bla SHV-1 , bla SHV-12 , bla SHV-32 and bla TEM-1 genes. Moreover, we characterized the plasmid-mediated quinolone resistance genes, aac(6')-Ib-cr and qnrB2 , which were detected in seven (11.7%) and two (3.3%) isolates, respectively. In this study various types of antibiotic resistance genes have been identified in Gram-negative bacteria from Palestinian hospitals, many of which are reported in the Middle East area for the first time. 相似文献
127.
Abdel-Hamid A. Hamdy Elsayed A. Aboutabl Somayah Sameer Ahmed A. Hussein Ana R. Díaz-Marrero Jos Darias Mercedes Cueto 《Steroids》2009,74(12):927-930
Bioassay-guided purification of an ethanolic extract of Cystoseira myrica against HEPG-2 (liver) and HCT116 (colon) human cancer cell lines led to the isolation of 3-keto-22-epi-28-nor-cathasterone, 1 and cholest-4-ene-3,6-dione, 2. This finding allowed us to report for the first time that a brassinosteroid-related metabolite occurs in seaweed. These compounds showed activity in the range of 12.38–1.16 μM with selective activity of compound 2 to liver cancer cell lines. 相似文献
128.
M.S. Al-Khalifa H.S. Hussein F.M. Diab G.M. Khalil 《Saudi Journal of Biological Sciences》2009,16(2):63-67
Blood samples from camels, sheep, goats and cattle from six Regions in Saudi Arabia were examined for blood parasites. Asir Region camels were disinfected while those of the Eastern, Jazan, Northern Frontiers, Riyadh and Tabouk Regions were infected with Trypanosoma evansi (5–40%), those of Riyadh and the Eastern Regions were infected with Dipetalonema evansi (1–6%) and those of the Eastern, Jazan and Riyadh Regions were infected with Eperythrozoon species (8–20%). Sheep and goats of all tested regions were infected with Theilaria hirci (4–20% and 6–14%, respectively), Theilaria ovis (5–19% and 6–24%, respectively) and Eperthrozoon ovis (2–9% and 2–8%, respectively). Sheep of the Eastern and Northern Frontiers Regions were also infected with Anaplasma ovis (2%) and also those of the Eastern Region were infected with Babesia motasi (4%) as well. Cattle of Asir and Eastern Regions were infected with Anaplasma marginale (1–3.4%) and those of the Eastern, Jazan and Riyadh Regions were infected with Theileria annulata (11.3–25%) and Eperthrozoon wenyoni (1–4%). Moreover, Jazan cattle were infected with Babesia bigemina (6%) and a benign Theileria species (27%). Some of these parasites are recorded in new localities indicating that they are spreading in the country. Also, this is the first report in Saudi Arabia of D. evansi in camels, A. ovis and B. motasi in sheep and A. marginale and B. bigemina in cattle. These parasites may be introduced into the country with infected livestock infested with the vectors of these parasites. The suspected vectors of the detected parasites in Saudi Arabia is discussed. Follow up surveys of blood parasites are recommended to assess their distribution and infection rates in the livestock of all Regions of Saudi Arabia, to make plans for control measures against their vectors. 相似文献
129.
Human bone marrow derived-mesenchymal (skeletal) stem (MSC) cells are a group of non-hematopoietic stem cells residing in the perivascular niches in bone marrow. These cells have the capacity to differentiate mainly into mesoderm-type cells such as osteoblasts, chondrocytes and adipocytes and possibly but not proven to non-mesodermal cell types. Recently, there has been an increased interest in understanding the biology of MSC due to their potential use in cell-based therapy for multiple degenerative diseases. Here, we will provide an update on the current status of these novel therapeutic opportunities. J. Cell. Physiol. 218: 9-12, 2009. (c) 2008 Wiley-Liss, Inc. 相似文献
130.
Walker JR Alshafie G Nieves N Ahrens J Clagett-Dame M Abou-Issa H Curley RW 《Bioorganic & medicinal chemistry》2006,14(9):3038-3048
All-trans retinoic acid analogues such as N-(4-hydroxyphenyl)retinamide (4-HPR) are effective chemopreventive and chemotherapeutic agents but their utility has been hampered by dose-limiting side effects. The glucuronide derivatives of 4-HPR, the oxygen-linked 4-HPROG and the carbon-linked 4-HPRCG, have been found to be more effective agents. The synthetic route to the fully C-linked analogue of 4-HPROG (4-HBRCG), which employs Suzuki coupling and Umpolung chemistries as key methodologies, is shown. The results of this study show 4-HBRCG to be an effective chemotherapeutic agent in a rat mammary tumor model while being devoid of classical retinoid toxicities. 相似文献