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471.
Ahmed B Al-Rehaily AJ Mossa JS 《Zeitschrift für Naturforschung. C, Journal of biosciences》2002,57(1-2):17-20
The aerial parts of Barbeya oleoides Schweinf (Family: Barbeyaceae) has afforded a new phenolic indane type component, which has been characterized as (6R, 4aR, 5aR)-5, 4a, 5a-trihydroindeno- (1, 2-a) indane-2, 4, 9-triol-6-O-beta-acetate (1) on the basis of spectral analysis and has been designated as barbeyol. 相似文献
472.
Five new furoquinoline alkaloids, namely tecleabine (1), tecleoxine (2), isotecleoxine (3), methylnkolbisine (4) and chlorodesnkolbisine (5) were isolated from the aerial parts of Teclea nobilis, together with seven known furoquinoline derivatives; one acridone alkaloid, and one known flavanone. The structures of the alkaloids 1-5 were established by 1D and 2D NMR spectral data, including COSY, HMQC and HMBC experiments, as well as HRMS. 相似文献
473.
The benefit of intravenous abciximab as an adjunctive to percutaneous coronary intervention has been demonstrated in large-scale randomized studies. The role of intravenous abciximab is being defined in carotid angioplasty and stent placement as the procedure is gaining popularity for the treatment of high-grade carotid stenosis in patients considered high-risk for carotid endarterectomy. This paper summarizes the pathophysiological basis and the available data for the use of abciximab as an adjunct to carotid artery stenting. 相似文献
474.
Pyruvate formate lyase and acetate kinase are essential for anaerobic growth of Escherichia coli on xylose 下载免费PDF全文
During anaerobic growth of bacteria, organic intermediates of metabolism, such as pyruvate or its derivatives, serve as electron acceptors to maintain the overall redox balance. Under these conditions, the ATP needed for cell growth is derived from substrate-level phosphorylation. In Escherichia coli, conversion of glucose to pyruvate yields 2 net ATPs, while metabolism of a pentose, such as xylose, to pyruvate only yields 0.67 net ATP per xylose due to the need for one (each) ATP for xylose transport and xylulose phosphorylation. During fermentative growth, E. coli produces equimolar amounts of acetate and ethanol from two pyruvates, and these reactions generate one additional ATP from two pyruvates (one hexose equivalent) while still maintaining the overall redox balance. Conversion of xylose to acetate and ethanol increases the net ATP yield from 0.67 to 1.5 per xylose. An E. coli pfl mutant lacking pyruvate formate lyase cannot convert pyruvate to acetyl coenzyme A, the required precursor for acetate and ethanol production, and could not produce this additional ATP. E. coli pfl mutants failed to grow under anaerobic conditions in xylose minimal medium without any negative effect on their survival or aerobic growth. An ackA mutant, lacking the ability to generate ATP from acetyl phosphate, also failed to grow in xylose minimal medium under anaerobic conditions, confirming the need for the ATP produced by acetate kinase for anaerobic growth on xylose. Since arabinose transport by AraE, the low-affinity, high-capacity, arabinose/H+ symport, conserves the ATP expended in pentose transport by the ABC transporter, both pfl and ackA mutants grew anaerobically with arabinose. AraE-based xylose transport, achieved after constitutively expressing araE, also supported the growth of the pfl mutant in xylose minimal medium. These results suggest that a net ATP yield of 0.67 per pentose is only enough to provide for maintenance energy but not enough to support growth of E. coli in minimal medium. Thus, pyruvate formate lyase and acetate kinase are essential for anaerobic growth of E. coli on xylose due to energetic constraints. 相似文献
475.
476.
Aslan A Izgut-Uysal N Boneval C Melikoglu M 《Prostaglandins, leukotrienes, and essential fatty acids》2004,71(2):111-115
It is unclear whether massive small bowel resection (SBR) affects prostaglandin E2 synthesis in the gastrointestinal tracts. Thus the aim of this study was to investigate possible changes over tissue levels of prostaglandin E2 in the stomach and ileum after massive proximal SBR. Female Swiss-Albino rats underwent control operation (groups 1, 3, 5) or an 80% SBR (groups 2, 4, 6). The specimens were obtained during relaparotomy at 3 days in groups 1 and 2, at 9 days in groups 3 and 4, at 15 days in groups 5 and 6. Group 2 vs. groups 1 and 6, group 4 vs. groups 3 and 6 had significant increase in the levels of gastric acid (P < 0.01, P < 0.05, respectively). Gastric prostaglandin E2 levels markedly increased in group 2 compared to group 1 (P < 0.01). Ileal prostaglandin E2 levels showed to be significantly higher in group 6 when compared with groups 2, 4, and 5 (P < 0.05). Gastric acidity increased at 3 and 9 days, decreased thereafter at 15 days following massive proximal SBR. While resected rats had increased levels of gastric prostaglandin E2 at 3 days, ileal prostaglandin E2 was markedly elevated at 15 days. Therefore, we conclude that prostaglandin E2 may have a possible role in regulating intestinal adaptation at the end of the adaptive process, and contribute to cytoprotective barrier function in the ileum and stomach at early and late periods of the intestinal adaptation, respectively. 相似文献
477.
The dermatophyte Trichophyton mentagrophytes var. erinacei isolated from patients infected with tinea cruris was cultured in Sabouraud dextrose broth, from which an exocellular kenitinase
extract was obtained. The keratinase was partially purified with sephadix G-100 gel filtration. Some biochemical characteristics
of the purified enzyme were examined. Its molecular weight was estimated to be 38000 dalton on sodium dodecyle sulfate polyacrylmide
gel electrophoresis (SDS-PAGE). The optimal pH was 5.5 and optimal temperature for the highest keratinase activity was 50°C.
The enzyme activity was specifically increased against guinea pig hair and fibrous protein and inhibited by phenylmethylsulfonylfloride.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
478.
Marie Rogne Oksana Svaerd Julia Madsen‐Østerbye Adnan Hashim Geir E. Tjønnfjord Judith Staerk 《Journal of cellular and molecular medicine》2018,22(5):2846-2855
Cytokinesis failure leads to the emergence of tetraploid cells and multiple centrosomes. Chronic lymphocytic leukaemia (CLL) is the most common haematological malignancy in adults and is characterized by clonal B cell expansion. Here, we show that a significant number of peripheral blood CLL cells are arrested in cytokinesis and that this event occurred after nuclear envelope reformation and before cytoplasmic abscission. mRNA expression data showed that several genes known to be crucial for cell cycle regulation, checkpoint and centromere function, such as ING4, ING5, CDKN1A and CDK4, were significantly dysregulated in CLL samples. Our results demonstrate that CLL cells exhibit difficulties in completing mitosis, which is different from but may, at least in part, explain the previously reported accumulation of CLL cells in G0/1. 相似文献
479.
As the Black Sea and Marmara Sea population of the Broadnosed Pipefish Syngnathus cf. argentatus show some morphological differences from the Mediterranean Sea populations, some authors regard it as an endemic species Syngnathus argentatus Pallas, 1814, while others consider it as a synonym of S. typhle Linnaeus, 1758. The aim of this study is to compare the populations of the Black Sea and Sea of Marmara with the Aegean Sea population, using a combination of morphological and molecular characters, in order to clarify their taxonomic status. Sampling was carried out at three stations in the Black Sea, two in the Sea of Marmara and three in the Aegean Sea, and a total of 24 morphometric and 6 meristic characters were examined. Metric data were analysed by Principal Component Analysis (PCA) and phylogenetic relationships between the populations were analysed using both cytochrome oxidase subunit 1 (COI) gene and cytochrome b (cyt-b) gene sequences. Although constant differences were observed in snout depths between the Black Sea/Marmara Sea and the Aegean Sea populations, other morphological features and genetic analysis did not enable these populations to be differentiated. These findings indicate that S. argentatus is a synonym of S. typhle. 相似文献
480.
The synthesis of N‐benzoylindoles as inhibitors of rat erythrocyte glucose‐6‐phosphate dehydrogenase and 6‐phosphogluconate dehydrogenase 下载免费PDF全文
Sinan Bayindir Yusuf Temel Adnan Ayna Mehmet Ciftci 《Journal of biochemical and molecular toxicology》2018,32(9)
Glucose‐6‐phosphate dehydrogenase (G6PD) and 6‐phosphogluconate dehydrogenase (6PGD) play an important function in various biochemical processes as they generate reducing power of the cell. Thus, metabolic reprogramming of reduced nicotinamide adenine dinucleotide phosphate (NADPH) homeostasis is reported to be a vital step in cancer progression as well as in combinational therapeutic approaches. In this study, N‐benzoylindoles 9a‐ ‐ 9d , which form the main framework of many natural indole derivatives such as indomethacin and N‐benzoylindoylbarbituric acid, were synthesized through three easy and effective steps as an in vitro inhibitor effect of G6PD and 6PGD. The N‐benzoylindoles inhibited the enzymatic activity with IC50 in the range of 3.391505 μM for G6PD and 2.19–990 μM for 6PGD. 相似文献