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971.
Wojewódzka M Kruszewski M Buraczewska I Xu W Massuda E Zhang J Szumiel I 《Acta biochimica Polonica》2007,54(1):63-69
Sirtuins (type III histone deacetylases) are an important member of a group of enzymes that modify chromatin conformation. We investigated the role of sirtuin inhibitor, GPI 19015, in double strand break (DSB) repair in CHO-K1 wt and xrs-6 mutant cells. The latter is defective in DNA-dependent protein kinase (DNA-PK)-mediated non-homologous end-joining (D-NHEJ). DSB were estimated by the neutral comet assay and histone gammaH2AX foci formation. We observed a weaker effect of GPI 19015 treatment on the repair kinetics in CHO wt cells than in xrs6. In the latter cells the increase in DNA repair rate was most pronounced in G1 phase and practically absent in S and G2 cell cycle phases. The decrease in the number of histone gammaH2AX foci was faster in xrs6 than in CHO-K1 cells. The altered repair rate did not affect survival of X-irradiated cells. Since in G1 xrs6 cells DNA-PK-dependent non-homologous end-joining, D-NHEJ, does not operate, these results indicate that inhibition of sirtuins modulates DNA-PK-independent (backup) non-homologous end-joining, B-NHEJ, to a greater extent than the other DSB repair system, D-NHEJ. 相似文献
972.
OBJECTIVE: To evaluate the value of cytologic examination in the diagnosis of laryngeal tumors. STUDY DESIGN: A series of 100 patients with suspected tumorous lesions of the larynx were included in the study. The material for cytologic analysis was obtained by use of a modified instrument, that is, a slightly concave discoid knife, during direct microlaryngoscopy, followed by biopsy for paraffin and frozen section histopathology. The findings obtained by cytology and frozen section histopathology were compared with the findings of paraffin section histopathology. RESULTS: Cytology showed an 83.9% sensitivity, 100% specificity and 90% accuracy compared with histopathologic findings (p < 0.05; chi2 = 7.7). Frozen section pathohistology vs. paraffin section histopathology showed an 80.6% sensitivity, 97.4% specificity and 87% accuracy (p < 0.05; chi2 = 8.1). CONCLUSION: Cytologic examination showed higher accuracy compared to frozen section histopathology, also giving an insight into the type of laryngeal pathology in the case of precancerous lesions. The use of cytology and frozen section histopathology during direct microlaryngoscopy improves clinical diagnostic accuracy. 相似文献
973.
Barley leaf discs maintained in dark accumulated a massive amount of putrescine (Put), lost chlorophyll and senescenced rapidly.
At the same time RNase activity increased significantly. Exogenous spermidine (Spd) inhibited RNase activity, the loss of
chlorophyll and degradation of the proteins from thylakoid membranes. Using SDS-PAGE and immunoblot analysis it was shown
that spermidine was effective in the retardation of the loss of LHCPII observed in water-treated detached leaves. Analysis
of PSII particles isolated from leaf fragments floated in water in the dark revealed the presence of Put, Spd and Spm. In
spermidine treated leaves the level of this polyamine in photosystem II was above 5-fold higher than in control. The experimental
findings obtained in this study provide evidence that applied spermidine interacts directly with thylakoid membranes so that
they become more stable to degradation during senescence. 相似文献
974.
M. Pazzagli Irena Bronstein A. K. Campbell P. Pinzani A. Roda K. V. Wood 《Luminescence》1998,13(5):285-285
975.
Daniella Schatz Guy Schleyer Marius R. Saltvedt Ruth-Anne Sandaa Ester Feldmesser Assaf Vardi 《The ISME journal》2021,15(12):3714
Extracellular vesicles are produced by organisms from all kingdoms and serve a myriad of functions, many of which involve cell-cell signaling, especially during stress conditions and host-pathogen interactions. In the marine environment, communication between microorganisms can shape trophic level interactions and population succession, yet we know very little about the involvement of vesicles in these processes. In a previous study, we showed that vesicles produced during viral infection by the ecologically important model alga Emiliania huxleyi, could act as a pro-viral signal, by expediting infection and enhancing the half-life of the virus in the extracellular milieu. Here, we expand our laboratory findings and show the effect of vesicles on natural populations of E. huxleyi in a mesocosm setting. We profile the small-RNA (sRNA) cargo of vesicles that were produced by E. huxleyi during bloom succession, and show that vesicles applied to natural assemblages expedite viral infection and prolong the half-life of this major mortality agent of E. huxleyi. We subsequently reveal that exposure of the natural assemblage to E. huxleyi-derived vesicles modulates not only host-virus dynamics, but also other components of the microbial food webs, thus emphasizing the importance of extracellular vesicles to microbial interactions in the marine environment.Subject terms: Virus-host interactions, Microbial ecology, Water microbiology 相似文献
976.
Phytochemical and Bioactive Potential of in vivo and in vitro Grown Plants of Centaurea ragusina L. – Detection of DNA/RNA Active Compounds in Plant Extracts via Thermal Denaturation and Circular Dichroism 下载免费PDF全文
977.
Tanja Žuna Pfeiffer Dubravka Špoljarić Maronić Vanda Zahirović Filip Stević Melita Mihaljević 《Biodiversity and Conservation》2017,26(2):439-460
Intensive human activities have resulted in a critical reduction of grasslands in Croatia, one of the richest Europian countries in terms of biodiversity. Sub-Pannonic steppic grasslands are very rare, only few occur in the continental part of Croatia and most of them are protected as NATURA 2000 sites. We studied vascular flora of the Sub-Pannonic stepic grassland with the aim to examine the changes in plant communities 15 years from the mowing application. Results showed that hand mowing once per year at the end of vegetation season increased the species diversity as well as the number of medium and low growth taxa. The critically endangered, nearly threatened and vulnerable species remained preserved. The occurrence of trees, shrubs and invasive species as a consequence of succession and anthropogenic influences could be important threat for steppe-like grassland flora. From a conservation point of view infrequent mowing regime could be an effective management tool, although it needs to be adapted to regional and local circumstances for maintaining high biodiversity of steppe-like grasslands and valuable plant species. 相似文献
978.
Kamil J. Kuder Dorota Łażewska Maria Kaleta Gniewomir Latacz Tim Kottke Agnieszka Olejarz Tadeusz Karcz Andrzej Fruziński Katarzyna Szczepańska Janina Karolak-Wojciechowska Holger Stark Katarzyna Kieć-Kononowicz 《Bioorganic & medicinal chemistry》2017,25(10):2701-2712
As a continuation of our search for novel histamine H3 receptor ligands a series of twenty new tert-amyl phenoxyalkylamine derivatives (2–21) was synthesized. Compounds of four to eight carbon atoms spacer alkyl chain were evaluated on their binding properties at human histamine H3 receptor (hH3R). The highest affinities were observed for pentyl derivatives 6–8 (Ki = 8.8–23.4 nM range) and among them piperidine derivative 6 with Ki = 8.8 nM. Structures 6, 7 were also classified as antagonists in cAMP accumulation assay (with EC50 = 157 and 164 nM, respectively). Moreover, new compounds were also evaluated for anticonvulsant activity in Antiepileptic Screening Program (ASP) at National Institute of Neurological Disorders and Stroke (USA). Seven compounds (2–4, 9, 11, 12 and 20) showed anticonvulsant activity at maximal electroshock (MES) test in the dose of 30 mg/kg at 0.5 h. In the subcutaneous pentetrazole (scMET) test compound 4 showed protection at 100 and 300 mg/kg dose at mice, however compounds showed high neurotoxicity in rotarod test at used doses. Also, molecular modeling studies were undertaken, to explain affinity of compounds at hH3R (taking into the consideration X-ray analysis of compound 18). In order to estimate “drug-likeness” of selected compounds in silico and experimental evaluation of lipophilicity, metabolic stability and cytotoxicity was performed. 相似文献
979.
980.
Helena Kapitanović Vidak Tina Catela Ivković Zoran Vidak Sanja Kapitanović 《Molecular neurobiology》2017,54(2):930-938
Cerebral palsy (CP) is a nonprogressive motor disorder caused by white matter damage in the developing brain. Recent epidemiological and clinical data suggest intrauterine infection/inflammation as the most common cause of preterm delivery and neonatal complications, including CP. Cyclooxygenases are key enzymes in the conversion of arachidonic acid to prostaglandins. The COX family consists of two isoforms, COX-1 and COX-2. In the brain, COX-2 is constitutively expressed at high levels on pyramidal neurons, while COX-1 is predominantly expressed by microglia and can be upregulated in pathological conditions, such as infection, ischemia and traumatic brain injury. Single nucleotide polymorphisms in the COX-1 and COX-2 gene could have profound effects on COX-1 and COX-2 expression and, directly or indirectly, influence the pathogenesis, development and severity of CP. In this study we investigated the association between single nucleotide polymorphisms of the COX-1 and COX-2 gene and susceptibility to cerebral palsy in very preterm infants. The results of our study showed the association between COX-1 high expression genotype (?842 AA) and COX-1 high expression allele ?842A and risk of CP in infants with cystic periventricular leucomalacia (cPVL). Our results support an important role of COX-1 enzyme on microglial activation during neuroinflammation resulting in huge neuroinflammatory response and the proinflammatory mediator overproduction, with the serious white matter damage and CP development as a consequence. 相似文献