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排序方式: 共有335条查询结果,搜索用时 281 毫秒
1.
H Zengil Z S Ercan E Onuk R K Turker 《Prostaglandins, leukotrienes, and essential fatty acids》1990,40(1):13-16
The preventive effects of nocloprost, nileprost, iloprost and (15S)-15-Methyl-prostaglandin E2 were studied in the rat gastric mucosal damage induced by restraint-cold stress, indomethacin and ethanol. Nocloprost was found to be the most potent orally active compound against rat mucosal damage induced by all noxious stimuli used in this study. Both nocloprost and iloprost were more effective on stress-induced ulcers than on those induced by indomethacin and ethanol. Nocloprost and 15-methyl prostaglandin E2 were also more active on ethanol-induced mucosal damage than on induced by indomethacin. No significant differences were obtained with iloprost and nileprost on indomethacin and ethanol-induced mucosal injury. These results indicate a more potent oral antiulcer activity of nocloprost. 相似文献
2.
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
3.
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
4.
5.
Complex chromosomal rearrangements are very rare chromosomal abnormalities. Individuals with a complex chromosomal rearrangement can be phenotypically normal or display a clinical abnormality. It is believed that these abnormalities are due to either microdeletions or microduplications at the translocation breakpoints or as a result of disruption of the genes located in the breakpoints. In this study we describe a 2-year-old child with mental retardation and developmental delay in whom a de novo apparently balanced exceptional complex chromosomal rearrangement was found through conventional cytogenetic analysis. Using both cytogenetic and FISH analysis, the patient's karyotype was found to be: 46,XY,der(5)t(5;7)(p15.1;7q34),t(5;8)(q13.1;8q24.1)dn. A large, clinically significant deletion which encompassed 887.69 kb was detected at the 5q12.1–5q12.3 (chr5:62.886.523–63.774.210) genomic region using array-CGH. This deleted region includes the HTR1A and RNF180 genes. This is the first report of an individual with an apparently balanced complex chromosomal rearrangement in conjunction with a microdeletion at 5q12.1–5q12.3 in which there are both mental-motor retardation and dysmorphia. 相似文献
6.
Asheesh Gupta Pinar Avci Magesh Sadasivam Rakkiyappan Chandran Nivaldo Parizotto Daniela Vecchio Wanessa C.M.A. de Melo Tianhong Dai Long Y. Chiang Michael R. Hamblin 《Biotechnology advances》2013
Phototherapy can be used in two completely different but complementary therapeutic applications. While low level laser (or light) therapy (LLLT) uses red or near-infrared light alone to reduce inflammation, pain and stimulate tissue repair and regeneration, photodynamic therapy (PDT) uses the combination of light plus non-toxic dyes (called photosensitizers) to produce reactive oxygen species that can kill infectious microorganisms and cancer cells or destroy unwanted tissue (neo-vascularization in the choroid, atherosclerotic plaques in the arteries). The recent development of nanotechnology applied to medicine (nanomedicine) has opened a new front of advancement in the field of phototherapy and has provided hope for the development of nanoscale drug delivery platforms for effective killing of pathological cells and to promote repair and regeneration. Despite the well-known beneficial effects of phototherapy and nanomaterials in producing the killing of unwanted cells and promoting repair and regeneration, there are few reports that combine all three elements i.e. phototherapy, nanotechnology and, tissue repair and regeneration. However, these areas in all possible binary combinations have been addressed by many workers. The present review aims at highlighting the combined multi-model applications of phototherapy, nanotechnology and, reparative and regeneration medicine and outlines current strategies, future applications and limitations of nanoscale-assisted phototherapy for the management of cancers, microbial infections and other diseases, and to promote tissue repair and regeneration. 相似文献
7.
Nikos Poulakakis Paschalia Kapli Afroditi Kardamaki Eirini Skourtanioti Bayram Göcmen Çetin Ilgaz Yusuf Kumlutaş Aziz Avci Petros Lymberakis 《Biological journal of the Linnean Society. Linnean Society of London》2013,108(3):619-635
The colonization patterns of oceanic islands are often interpreted through transmarine dispersal. However, in islands with intense human activities and unclear geological history, this inference may be inappropriate. Cyprus is such an island, whose geotectonic evolution has not been clarified yet to the desired level for biogeographical reconstructions, leaving the questions of ‘how the Cypriote biota arrived’ and ‘does the dispersal have the formative role in patterns of its diversification’ unanswered. Here, we address these issues through a reconstruction of the evolutionary history of six herptiles (Ablepharus budaki, Ophisops elegans, Acanthodactylus schreiberi, Telescopus fallax, Pelophylax cf. bedriagae, and Hyla savignyi) by means of mitochondrial DNA (cytochrome b and 16S rRNA), applying a Bayesian phylogenetic, biogeographical, and chronophylogenetic analyses. The phylogeographical analyses show that the colonization history of those species in Cyprus started in the late Miocene and extended into the Pliocene and Pleistocene, with geodispersal, transmarine dispersal, and human‐mediated dispersal having their share in shaping the diversification of Cypriote herptiles. The revealed patterns could be divided into three biogeographical categories: old colonizers that arrived in Cyprus during the late Miocene or early Pliocene either by a land bridge (geodispersal) which connected Cyprus with the mainland or by transmarine dispersal, younger colonizers that reached the island through transmarine dispersal from the Middle East, and new settlers that arrived through human‐induced (voluntary or not) introductions. This work advances our knowledge of the biogeography of Cyprus and highlights the need to consider both geo‐ and transmarine dispersal when dealing with islands whose associations do not have a straightforward interpretation. © 2013 The Linnean Society of London 相似文献
8.
Gulden Koclar Avci Nursen Coruh Ufuk Bolukbasi Zumrut B. Ogel 《Applied microbiology and biotechnology》2013,97(2):661-672
The thermophilic fungus Scytalidium thermophilum produces a novel bifunctional catalase with an additional phenol oxidase activity (CATPO); however, its phenol oxidation spectrum is not known. Here, 14 phenolic compounds were selected as substrates, among which (+)-catechin, catechol, caffeic acid, and chlorogenic acid yielded distinct oxidation products examined by reversed-phase HPLC chromatography method. Characterization of the products by LC-ESI/MS and UV–vis spectroscopy suggests the formation of dimers of dehydrocatechin type B (hydrophilic) and type A (hydrophobic), as well as oligomers, namely, a trimer and tetramer from (+)-catechin, the formation of a dimer and oligomer of catechol, a dimer from caffeic acid with a caffeicin-like structure, as well as trimeric and tetrameric derivatives, and a single major product from chlorogenic acid suggested to be a dimer. Based on the results, CATPO oxidizes phenolic compounds ranging from simple phenols to polyphenols but all having an ortho-diphenolic structure in common. The enzyme also appears to have stereoselectivity due to the oxidation of (+)-catechin, but not that of epicatechin. It is suggested that CATPO may contribute to the antioxidant mechanism of the fungus and may be of value for future food and biotechnology applications where such a bifunctional activity would be desirable. 相似文献
9.
Lysozyme (1,4-β-N-acetylmuramidase) is a lytic enzyme, which degrades the bacterial cell wall. Lysozyme has been of interest in medicine, cosmetics, and food industries because of its anti-bactericidal effect. Kluyveromyces lactis K7 is a genetically modified organism that expresses human lysozyme. There is a need to improve the human lysozyme production by K. lactis K7 to make the human lysozyme more affordable. Biofilm reactor provides high biomass by including a solid support, which microorganisms grow around and within. Therefore, the aim of this study was to produce the human lysozyme in biofilm reactor and optimize the growth conditions of K. lactis K7 for the human lysozyme production in biofilm reactor with plastic composite support (PCS). The PCS, which includes polypropylene, soybean hull, soybean flour, bovine albumin, and salts, was selected based on biofilm formation on PCS (CFU/g), human lysozyme production (U/ml), and absorption of lysozyme inside the support. To find the optimum combination of growth parameters, a three-factor Box–Behnken design of response surface method was used. The results suggested that the optimum conditions for biomass and lysozyme productions were different (27 °C, pH 6, 1.33 vvm for biomass production; 25 °C, pH 4, no aeration for lysozyme production). Then, different pH and aeration shift strategies were tested to increase the biomass at the first step and then secrete the lysozyme after the shift. As a result, the lysozyme production amount (141 U/ml) at 25 °C without pH and aeration control was significantly higher than the lysozyme amount at evaluated pH and aeration shift conditions (p?<?0.05). 相似文献
10.
Dilek Pandir Recep Sahingoz Fahriye Sumer Ercan 《Biocontrol Science and Technology》2013,23(12):1402-1411
This study investigated the effect of strong magnetic fields as insecticidal activity on Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) larvae and eggs at different stages of development and their preference by the egg parasitoid, Trichogramma embryophagum Hartig (Hymenoptera: Trichogrammatidae). Eggs ranging in age from 24-h to 48-h and 72-h-old and larvae (1 to 2 days) were exposed to 1.4 Tesla (T) magnetic fields from a DC power supply at 50 Hz for different time periods (3, 6, 12, 24, 48 and 72 h). Twelve hours of exposure at 1.4 T was toxic to 24-h-old eggs of E. kuehniella. The 72-h-old host eggs treated with 1.4 T for 6–72 h were not significantly preferred by T. embryophagum. The magnetic field was toxic to 24-h-old eggs of E. kuehniella exposed to 1.4 T for 12. The treatment of magnetic fields on the 72-h-old host egg with 1.4 T at 6–72 h was not significantly preferred by T. embryophagum. Magnetization of 24-h-old eggs of E. kuehniella for 3 h could be effectively used with T. embryophagum as sterilised host eggs. These eggs were markedly preferred by T. embryophagum. The LT50 and LT99 values of magnetic fields at different egg stages of E. kuehniella, and larvae were measured. A level of 1.4 T at 72 h completely prevented the development of the larvae. There was no significant effect on larval survival at 1.4 T at 48 and 72 h. Increasing magnetic fields exposure times for eggs that were 24-h, 48-h and 72-h-old prevented larval emergence and increased their mortality rate. Consequently, magnetic fields could be used in controlling stored-product pest eggs and larvae of E. kuehniella. 相似文献