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排序方式: 共有759条查询结果,搜索用时 31 毫秒
741.
742.
Sara Mohamed Naguib Abdel Hafez Fatma Alzhraa Fouad Abdelbaky Allam Eman Elbassuoni 《Cell stress & chaperones》2021,26(1):199
Chronic stress has been related to multiple diseases. Inflammation is proposed strongly to link stress to stress-related diseases in different organs, such as small intestine, colon, and brain. However, stress cellular effect on the pancreatic tissue, especially the exocrine one, had received relatively little attention. This work aimed to evaluate the cellular effect of chronic immobilization stress on the pancreatic tissue function and structure along with evaluating the sex role in this type of pancreatic injury. Thirty rats were equally divided into 5 groups: control male, control female, stressed male, stressed female, and stressed female with bilateral ovariectomy. Stressed rats were exposed to immobilization for 1 h/day, 6 days/week, for 3 weeks. Rats were then decapitated for further biochemical, histological, histo-morphometric, and immunohistochemical study. The results showed that, in male and female rats, chronic immobilization stress produced hypoinsulinemia and hyperglycemia, with increasing exocrine pancreatic injury markers by increasing oxidative and inflammatory status of the pancreatic tissue, and exhibited a degenerative effect on the pancreatic tissue. However, the stress-induced pancreatic effects were more obvious in male rats and female rats with bilateral ovariectomy than that in female rats. It could be concluded that male animals were more susceptible to stress-induced pancreatic damage than females. The ovarian hormones are responsible, at least partly, for pancreatic tissue protection since the stress-induced pancreatic injury in females was exacerbated by ovariectomy. In this study, inflammatory and oxidative stress differences in both sexes could provide a plausible explanation for sex differences. 相似文献
743.
S. Abdel Fattah A. A. E.-E. Rizk A. G. Motawie T. I. Abd El-Galil M. El Sebaie 《Biotechnic & histochemistry》2019,94(4):234-243
Although the risks of smoking are well known, the effects of exposure to nicotine on endocrine functions remain unclear. We investigated the deleterious effects of nicotine on the adrenal gland and the mechanisms of these changes in rats. The role of melatonin in ameliorating pathological changes also was investigated. We used 24 rats divided into four groups of six: group 1, control; group 2, nicotine treated; group 3, nicotine and melatonin treated; group 4, melatonin treated. We used histology; immunohistochemistry of inducible nitric oxide synthase (iNOS), vascular endothelial growth factor (VEGF) and tyrosine hydroxylase (TH); measured oxidative and antioxidative markers, malondialdehyde (MDA) and glutathione (GSH); and performed real-time PCR for NF-κB 65, IL1-B and IL6. We also performed histomorphometric analysis. Indentation and lamellar separation of the adrenal capsule, vacuolated degenerated cells and lymphocytic infiltration were observed in group 2. Vacuolated cells and cells with pyknotic nuclei also were detected in the zona reticularis and medulla of the same group. We observed improved shape and cellular lining of the gland in groups 3 and 4. Widespread expression of iNOS, VEGF and TH, increased area percent collagen, decreased GSH (56%) and increased MDA, NF-κB, IL1-B and IL-6 were observed in group 2. All parameters were ameliorated in groups 3 and 4. The effects of nicotine on the adrenal gland can be attributed to oxidative and inflammatory stress; melatonin ameliorates these effects. 相似文献
744.
745.
Several numerical schemes are proposed for the solution of Nonequilibrium Langevin Dynamics (NELD), and the strong rate of convergence for each scheme is analyzed. The schemes considered here employ specialised periodic boundary conditions that deform with the flow, namely Lees-Edwards and Kraynik-Reinelt boundary conditions and their generalisations. We show that care must be taken when implementing standard stochastic integration schemes with these boundary conditions in order to avoid a breakdown in the strong order of convergence. 相似文献
746.
Phytoplankton associations in two pools and their relationships with associated benthic flora 总被引:1,自引:1,他引:0
Summary The theory underlying the delineation of phytoplankton association is examined, and the associations of Abbot's pond and Priddy pool are characterised according to the conclusions derived from this examination. The importance of extended investigations is stressed. Abbot's pond has a eu-planktonic flora with abundant Asterionella formosa, Pandorina morum and Chrysococcus diaphanus. The euphytoplankton of Priddy pool consists of a very few species, of which Dinobryon sertularia is most abundant, but owing to the action of wind on the pool, many species are introduced into the open water by disturbance of benthic habitats. 相似文献
747.
748.
S A Al-Nagdy M O Abdel Rahman H I Heiba 《Comp. Biochem. Physiol. C, Comp. Pharmacol. Toxicol.》1986,85(1):163-166
Green onions (Allium cepa) were homogenized in a blender and extracted by normal extraction methods except that diethyl ether was used as the first extracting solvent. Different analytical procedures were used for the identification of the prostaglandins separated. TLC was applied using silica gel 60 F254 plates and a mixture of benzene, dioxane and acetic acid (20:10:1) as eluent, and the Rf values were compared with those of authentic samples. GC analysis on an SE 30 packed column and FID was applied; relative retention times of the onion extract components were measured and matched with authentic prostaglandin samples using cholesterol as an internal standard. GC-MS analyses using the same conditions adopted for GC analysis were conducted on a Finnigan MAT 112S instrument. Four peaks were identified. The prostaglandins identified were F1 alpha, E1, B1 and A2. 相似文献
749.
750.
Ghofrane Lahmadi Aida Lahmar Mansour Znati Mohamed Tahar Elaieb Mohamed Larbi Khouja Roberta Ascrizzi Guido Flamini Abdel Halim Harrath Leila Chekir-Ghedira Hichem Ben Jannet 《化学与生物多样性》2021,18(11):e2100315
In recent years, there has been a growing interest in the screening of natural active ingredients from Eucalyptus essential oils because of their evident importance in practical utility and their undeniable therapeutic properties. Based on this, the aim of the present study was to investigate the chemical profile of the essential oils of the trunk bark of Eucalyptus torquata Luehm. (ETEO), and E. salmonophloia F. Muell. (ESEO), growing in Tunisia. The in vitro cytotoxic properties of the extracted EOs were also evaluated against two human cancer cell lines: breast carcinoma cell lines MDA-MB-231 and colorectal cancer cell lines SW620. The analysis by gas chromatography coupled with mass spectrometry (GC/MS) led to the identification of 32 compounds from the ETEO, with the dominant constituents being the monoterpenes trans-myrtanol (73.4 %) and myrtenol (4.7 %), and the apocarotene (E)-β-ionone (3.9 %). In the case of ESEO, 29 compounds were identified with trans-myrtanol (25.0 %), decanoic acid (22.1 %), nonanoic acid (9.8 %), γ-elemene (6.5 %), γ-maaliene (5.5 %), and α-terpineol (5.3 %) as the main components. The cytotoxicity of EOs against the two chosen cell lines was tested using Crystal Violet Staining (CVS) assay and 5-fluorouracil as a reference drug. The two EOs exhibited a significant dose-dependent inhibition against the viability of the used cell lines. Their inhibitory effects were particularly observed towards SW620 colon carcinoma cells with IC50 values of 26.71±1.22 and 22.21±0.85 μg/mL, respectively, indicating that both oils were more cytotoxic for SW620 cells compared to MDA-MB-231 one. 相似文献