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981.
Marc Bossus Lbachir Mohammed Arthuro Londono Bernard Barbier Andr Tartar Pierre Druilhe Hlne Gras-Masse 《Journal of peptide science》1997,3(1):47-53
A 17-mer sequence was selected as a model to study the influence of modifications of terminal ends both on the conformation of a peptide and on its antigenicity towards naturally developing antibodies. This sequence corresponded to a tandemly repeated motif, found in a long repetitive region, with high helical propensity, of a Plasmodium falciparum liver-stage antigen (LSA-1), immunogenic in man. Our model peptide was synthesized with ionizable or non-ionizable ends, or modified in both extremities by introduction of the helix-promoting residue α-aminoisobutyric acid (Aib). Helical contribution, absent in the 17 amino-acid sequence possessing ionizable ends, was detectable when non-ionizable ends were introduced, and dramatically increased in the Aib-modified analogue. The presence of ionizable ends totally abolished reactivity towards human sera, otherwise detectable with the peptide possessing non-ionizable ends. While modification by Aib residues was neither detrimental nor beneficial to antigenicity in solution, it clearly resulted in an improved sensitivity of the specific antibody detection when used as solid-phase antigen in ELISA. © 1997 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
982.
983.
The P-budget of Dal Lake in Kashmir is described for a 12 month period. The lake is characterized by high P-loading (7.5 g · m−2 a−1) and had high P-retention (retention coefficient 0.32). P-loading in the lake showed positive and negative relations with flushing rate and P-retention respectively. A negative relation was similarly found existing between flushing and P-retention. The roles of various biotic and abiotic factors in the P-budget of the lake are described. 相似文献
984.
985.
Sherin Bakhashab Asma A Batarfi Najlaa Filimban Osama S Bajouh Ashraf Dallol Mohammed H Alqahtani 《Bioinformation》2021,17(11):904
Polycystic ovary syndrome (PCOS) is characterised by infertility, obesity, insulin resistance and clinical and/or biochemical signs of hyperandrogenism. Obesity is known to be correlated with PCOS causing ovulatory dysfunction and hormone imbalances. Moreover, fat mass and the obesity gene (FTO) were linked with obesity and PCOS. Therefore, it is of interest to determine the genotype and allele frequency for three FTO variants - rs17817449 (G/T), rs1421085 (C/T) and rs8050136 (A/C) -in western Saudi population. 95 PCOS patients and 94 controls were recruited for this study. The genetic variants were assayed using real-time polymerase chain reaction using TaqMan genotyping assays. The chi-squared test was applied to investigate the difference between single nucleotide polymorphisms on PCOS and control subjects, and binary logistic regression was used to determine the association of FTO variants with PCOS symptoms. Variants rs17817449 and rs1421085 were significantly linked with PCOS susceptibility in the study population. Rs17817449 and rs8050136 were significantly associated with hair loss in the PCOS group. Furthermore, rs1421085 and rs8050136 were associated with a high body mass index (BMI>30 kg/m2). Risk alleles in our population associated with hair loss and elevated BMI in women with PCOS were homozygous C for rs8050136. This data will help in defining the genetic predisposition of PCOS among women in western Saudi Arabia. 相似文献
986.
Hazem Elkady Alaa Elwan Hesham A. El-Mahdy Ahmed S. Doghish Ahmed Ismail Mohammed S. Taghour Eslam B. Elkaeed Ibrahim H. Eissa Mohammed A. Dahab Hazem A. Mahdy Mohamed M. Khalifa 《Journal of enzyme inhibition and medicinal chemistry》2022,37(1):397
A new series of benzoxazole derivatives were designed and synthesised to have the main essential pharmacophoric features of VEGFR-2 inhibitors. Cytotoxic activities were evaluated for all derivatives against two human cancer cell lines, MCF-7 and HepG2. Also, the effect of the most cytotoxic derivatives on VEGFR-2 protein concentration was assessed by ELISA. Compounds 14o, 14l, and 14b showed the highest activities with VEGFR-2 protein concentrations of 586.3, 636.2, and 705.7 pg/ml, respectively. Additionally, the anti-angiogenic property of compound 14b against human umbilical vascular endothelial cell (HUVEC) was performed using a wound healing migration assay. Compound 14b reduced proliferation and migratory potential of HUVEC cells. Furthermore, compound 14b was subjected to further biological investigations including cell cycle and apoptosis analyses. Compound 14b arrested the HepG2 cell growth at the Pre-G1 phase and induced apoptosis by 16.52%, compared to 0.67% in the control (HepG2) cells. The effect of apoptosis was buttressed by a 4.8-fold increase in caspase-3 level compared to the control cells. Besides, different in silico docking studies were also performed to get better insights into the possible binding mode of the target compounds with VEGFR-2 active sites. 相似文献
987.
Noor
A. Mohammed Israa
J. Hakeem Nikolas Hodges Francesco Michelangeli 《Bioscience reports》2022,42(1)
Doxorubicin (DOX) is a potent anticancer drug, which can have unwanted side-effects such as cardiac and kidney toxicity. A detailed investigation was undertaken of the acute cytotoxic mechanisms of DOX on kidney cells, using Cos-7 cells as kidney cell model. Cos-7 cells were exposed to DOX for a period of 24 h over a range of concentrations, and the LC50 was determined to be 7 µM. Further investigations showed that cell death was mainly via apoptosis involving Ca2+ and caspase 9, in addition to autophagy. Regucalcin (RGN), a cytoprotective protein found mainly in liver and kidney tissues, was overexpressed in Cos-7 cells and shown to protect against DOX-induced cell death. Subcellular localization studies in Cos-7 cells showed RGN to be strongly correlated with the nucleus. However, upon treatment with DOX for 4 h, which induced membrane blebbing in some cells, the localization appeared to be correlated more with the mitochondria in these cells. It is yet to be determined whether this translocation is part of the cytoprotective mechanism or a consequence of chemically induced cell stress. 相似文献
988.
Wagdy M. Eldehna Mohammed S. Taghour Tarfah Al-Warhi Alessio Nocentini Mostafa M. Elbadawi Hazem A. Mahdy Mohamed A. Abdelrahman Ohoud J. Alotaibi Nada Aljaeed Diaaeldin M. Elimam Kamyar Afarinkia Hatem A. Abdel-Aziz Claudiu T. Supuran 《Journal of enzyme inhibition and medicinal chemistry》2022,37(1):531
Different 2,4-thiazolidinedione-tethered coumarins 5a–b, 10a–n and 11a–d were synthesised and evaluated for their inhibitory action against the cancer-associated hCAs IX and XII, as well as the physiologically dominant hCAs I and II to explore their selectivity. Un-substituted phenyl-bearing coumarins 10a, 10 h, and 2-thienyl/furyl-bearing coumarins 11a–c exhibited the best hCA IX (KIs between 0.48 and 0.93 µM) and hCA XII (KIs between 0.44 and 1.1 µM) inhibitory actions. Interestingly, none of the coumarins had any inhibitory effect on the off-target hCA I and II isoforms. The sub-micromolar compounds from the biochemical assay, coumarins 10a, 10 h and 11a–c, were assessed in an in vitro antiproliferative assay, and then the most potent antiproliferative agent 11a was tested to explore its impact on the cell cycle phases and apoptosis in MCF-7 breast cancer cells to provide more insights into the anticancer activity of these compounds. 相似文献
989.
We studied photosynthetic acclimation of eastern hemlock [Tsuga canadensis (L.) Carr.] seedlings in the first month after sudden exposure of shade-grown seedlings to full sunlight. In a greenhouse
experiment, seedlings were grown under full sun or 80% shade, and after 7 months, a sample of the shaded trees was transferred
to full sun in the greenhouse. Photosynthetic responses of shaded, transferred, and sun trees were followed over the course
of 26 days to track short to medium-term acclimation responses. A partial acclimation of photosynthesis at high light occurred
in pre-existing (formed in the previous environment) and new foliage of transferred seedlings. This was associated with non-stomatal
limitations to photosynthesis. Pre-existing foliage of transferred plants had a prolonged reduction in the ratio of variable
to maximal fluorescence, and a limited capacity to adjust photochemical quenching or photosystem II quantum yield in the light
to increasing light intensity compared to sun foliage, and apparently had some difficulty sustaining non-photochemical quenching.
Seedling survival was only 58% among transferred seedlings, compared to 80% and 100% in the shade or sun groups, respectively.
Photosystem II quantum yield in the light, and photochemical and non-photochemical quenching were similar between newly formed
foliage of transferred and sun plants. These findings indicate that eastern hemlock depends strongly on the production of
new foliage for photosynthetic adjustments to high light, and that development of photosynthetic competence may be a gradual
process that occurs over successive foliar production cycles.
Received: 12 May 1998 / Accepted: 27 July 1998 相似文献
990.
Mohammed Mebarek Bia Seongjun Choe Barakaeli Abdieli Ndosi Hansol Park Yeseul Kang Chatanun Eamudomkarn Tilak Chandra Nath Sunmin Kim Hyeong-Kyu Jeon Dongmin Lee Keeseon S. Eom 《The Korean journal of parasitology》2021,59(5):457
Cystic echinococcosis is a zoonotic parasitic disease caused by Echinococcus species. Tanzania is one of the endemic countries with cystic echinococcosis. This study focussed on identifying genotypes of Echinococcus spp. in Tanzania. We collected 7 cysts from cattle in Mwanza municipal (n=4) and Loliondo district (n=3). The cysts from Mwanza were all E. ortleppi and fertile. In contrast, the cysts from Loliondo were all E. granulosus sensu stricto and sterile. Two from the 4 cysts were a new haplotype of E. ortleppi (G5). These results can improve the preventive and control programs for humans and livestock in Tanzania. To our knowledge, this study is considered the first to identify the genotype and haplotype of Echinococcus spp. in Tanzania. 相似文献