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S Aktan C Aykut B C Yegen U Ozkutlu I Okar S Ercan 《Prostaglandins, leukotrienes, and essential fatty acids》1992,46(4):287-290
Prostaglandin E2 (PGE2) and leukotriene C4 (LTC4) are the metabolites of arachidonic acid (AA) that increase in forebrain following global ischemia and reperfusion. These mediators are highly potent vasoconstrictors of cerebral arteries leading to enhanced vascular permeability that induces the formation of vasogenic edema. In this study, after developing an experimental animal model simulating the concept of ischemic penumbra in the rat, the levels of PGE2 and LTC4 produced in the forebrain were measured and the effects of these mediators in short duration and prolonged reperfusion were investigated and then correlated with neuropathological findings. We found statistically significant reduction both in PGE2 and LTC4-like activities after just 10 min ischemia (p less than 0.05, p less than 0.05). PGE2-like activity significantly increased in the 4th and 60th min of reperfusion (p less than 0.05, p less than 0.05). In the 15th min of reperfusion, PGE2 was found to be significantly reduced (p less than 0.005) that may be due to the formation of free oxygen radicals by activation of PG hydroperoxidase reaction that inhibits PGE2 production in the cyclooxygenase pathway. LTs were not significantly increased in any reperfused group. Inhibition of the lipoxygenase pathway of AA metabolism may occur as a result of 15-HPETE (15-hydroperoxyeicosatetraenoic acid) production. Pathologically, edema and degeneration of brain tissue were seen beginning from the 4th min of reperfusion that reached a peak in the 60th min of reperfusion which is in accordance with biochemical changes in the damaged tissue.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Our cytological analysis revealed high proportions of XX males in some housefly populations of Turkey. In contrast to earlier findings in Europe, on the British Islands, and in Japan, the XX male frequency in Turkey was not correlated to the geographical latitude. In general, the frequency of XX males was lower in populations from the central and eastern Anatolian highlands than from coastal regions, demonstrating a correlation of the sex-determining mechanisms to geographical altitude and perhaps other geographical characteristics. 相似文献
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Leukotriene C4 and prostaglandin E2 activities in the serum and cerebrospinal fluid during acute cerebral ischemia 总被引:2,自引:0,他引:2
S. Aktan C. Aykut S. Ercan 《Prostaglandins, leukotrienes, and essential fatty acids》1991,43(4):247-249
Lipoxygenase pathway products of arachidonic acid (AA) metabolism (known as leukotrienes, LTs) are produced in the brain during pathologic conditions such as ischemia, hemorrhage, trauma, and seizure in which the release of AA is sustained by the activation of local phospholipases. The most common type of LT in the central nervous system is an LTC4 which is a highly potent vasoconstrictor leading to increase in vascular permeability. In this study, we compared the serum (S) and cerebrospinal fluid (CSF) prostaglandin E2 (PGE2) and LTC4 levels in 13 consecutively admitted patients with acute cerebral ischemia aged 55-80 years with 10 age-matched controls. Patients with previous glucocorticosteroid and antiinflammatory drug usage were not included in the study. S and CSF samples were drawn during the first 72 h of the attack, and samples were evaluated by bioassay. There was no significant difference in S PGE2 and LTC4 values, whereas a significant difference was observed between CSF PGE2 and LTC4 values as compared with the control group. The high levels of CSF PGE2 and LTC4-like activity in acute cerebral ischemia may indicate that these mediators have a role to play in cerebral edema. The CSF PGE2/LTC4 ratio was also found to be reduced in the ischemic group implying higher LTC4 synthesis than PGE2 synthesis. In the light of these findings, we suggest that use of a selective antagonist of LTs may be helpful in reducing the ischemic penumbra during acute cerebral ischemia by controlling the vasogenic edema. 相似文献
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Murat alayan Cigdem Sonmez Mehmet Senes Ataman Gonel Ozlem Gulbahar Nurbanu Bursa Derun Taner Osman Celik Fidanci Ali Aykut Ulgu Mustafa Mahir Abdulvahit Sozuer Naim Ata Suayip Birinci 《Journal of Medical Biochemistry》2022,41(4):450
BackgroundAcross the world, 25-hydroxyvitamin D (25-OHD) deficiency is a major health problem associated with many chronic diseases in the geriatric population. Prior to this study, there were no data regarding 25-OHD levels among individuals over the age of 65 in Turkey. The aim of this study was to assess 25-OHD levels and seasonal variations in these values among people over the age of 65 in Turkey.MethodsThis study included vitamin D measurements taken in 2016, 2017, and 2018 from the Turkish population over the age of 65. The age, gender, and seasonal average data of the study population were defined. The study data were obtained from the database of the Ministry of Health, and a Kolmogorov-Smirnov test was used to assess the distribution of the data. Medians and interquartile ranges (IQRs) were calculated for all categories, as the data were nonparametric.ResultsThe number of vitamin D measurements taken from the geriatric individuals included in this study was 305,329 for 2016, 576,452 for 2017, and 752,837 for 2018. The medians and IQRs of the 25-OHD levels in this population were 16 μg/L (IQR 7.45-24.55 μg/L) for 2016, 16.1 μg/L (IQR 7.8-24.4 μg/L) for 2017, and 16.4 μg/L (IQR 8.95-23.85 μg/L) for 2018.ConclusionsWhile the 25-OHD levels of older men tended to increase during the period of seasonal sunlight in Turkey, this variability was observed in elderly women. This suggests that older women tend to live more sedentary lives and have insufficient sun exposure. Overall, the median 25-OHD levels of individuals over the age of 65 tended to decrease each year. 相似文献
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Özgür Aykut Kara Altan Gökşen Tosun Nazan Tekin Şaban Gökçe İsa 《Molecular biology reports》2021,48(4):3439-3449
Molecular Biology Reports - Heat shock protein 90 (Hsp90) is a key chaperone that is abnormally expressed in cancer cells, and therefore, designing novel compounds to inhibit chaperone activities... 相似文献
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Kadir Yesilbag Levent Aydin Ender Dincer Gizem Alpay A. Onur Girisgin Pelin Tuncer Aykut Ozkul 《Experimental & applied acarology》2013,60(2):253-261
Crimean-Congo hemorrhagic fever (CCHF) is an increasing health concern in Turkey since 2002. There were also some recent human cases from the South Marmara region of Turkey; thus, a tick survey was performed, and possible vector tick species for the CCHF virus were determined in the region. A total of 740 adult ticks were collected from infested livestock from five locations: Çanakkale-Biga, Bursa-Orhaneli, Bursa-Keles, Bal?kesir and Bilecik. Total of 11 tick species from the genera Hyalomma, Rhipicephalus, Dermacentor, Ixodes and Haemaphysalis were identified. Rhipicephalus ticks were dominant in the region; the most frequently observed tick species was R. turanicus, (53.1 %), and only 15.4 % of the identified ticks were H. marginatum. The occurrence of H. rufipes infestation in the region fort he first time. A total of 73 pools of adult ticks were tested with both an antigen-detecting ELISA and RT real-time PCR (RT rt PCR). The presence of the CCHF virus was demonstrated in 9 (12.3 %) of the tested tick pools. Although seven of the tick pools were positive for the CCHF virus with both of the methods, one pool was positive only with RT rt PCR and the other pool was only positive with the ELISA. Positive results were obtained from ticks collected from cattle, sheep and goats from two locations, Bursa-Orhaneli and Bilecik. The CCHF virus was detected in R. turanicus (n = 3), R. bursa (n = 2), H. marginatum (n = 2) and D. marginatus (n = 2) ticks. The results of this study confirm the presence of the CCHF virus and present preliminary data on the vector tick species in the southern Marmara region of Turkey. 相似文献
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Background
Cyclins regulate the cell cycle in association with cyclin dependent kinases (CDKs). CDKs are under inhibitory control of cyclin dependent kinase inhibitors (CDKIs). 相似文献8.
Pinyi Lu Raquel Hontecillas Vida Abedi Shiv Kale Andrew Leber Chase Heltzel Mark Langowski Victoria Godfrey Casandra Philipson Nuria Tubau-Juni Adria Carbo Stephen Girardin Aykut Uren Josep Bassaganya-Riera 《PloS one》2015,10(12)
Nucleotide-binding domain and leucine-rich repeat containing (NLR) family are intracellular sentinels of cytosolic homeostasis that orchestrate immune and inflammatory responses in infectious and immune-mediated diseases. NLRX1 is a mitochondrial-associated NOD-like receptor involved in the modulation of immune and metabolic responses. This study utilizes molecular docking approaches to investigate the structure of NLRX1 and experimentally assesses binding to naturally occurring compounds from several natural product and lipid databases. Screening of compound libraries predicts targeting of NLRX1 by conjugated trienes, polyketides, prenol lipids, sterol lipids, and coenzyme A-containing fatty acids for activating the NLRX1 pathway. The ligands of NLRX1 were identified by docking punicic acid (PUA), eleostearic acid (ESA), and docosahexaenoic acid (DHA) to the C-terminal fragment of the human NLRX1 (cNLRX1). Their binding and that of positive control RNA to cNLRX1 were experimentally determined by surface plasmon resonance (SPR) spectroscopy. In addition, the ligand binding sites of cNLRX1 were predicted in silico and validated experimentally. Target mutagenesis studies demonstrate that mutation of 4 critical residues ASP677, PHE680, PHE681, and GLU684 to alanine resulted in diminished affinity of PUA, ESA, and DHA to NLRX1. Consistent with the regulatory actions of NLRX1 on the NF-κB pathway, treatment of bone marrow derived macrophages (BMDM)s with PUA and DHA suppressed NF-κB activity in a NLRX1 dependent mechanism. In addition, a series of pre-clinical efficacy studies were performed using a mouse model of dextran sodium sulfate (DSS)-induced colitis. Our findings showed that the regulatory function of PUA on colitis is NLRX1 dependent. Thus, we identified novel small molecules that bind to NLRX1 and exert anti-inflammatory actions. 相似文献
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