排序方式: 共有210条查询结果,搜索用时 140 毫秒
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Salimi A Yousefi F Ghollasi M Daneshjou S Tavoli H Ghobadi S Khajeh K 《Journal of microbiology and biotechnology》2012,22(8):1077-1083
Previously, an extracellular α-amylase (BKA) had been purified from the culture of Bacillus sp. KR8104. Subsequently, the crystal structure of the active enzyme revealed a 422 amino acids polypeptide. In this study, the bka was cloned into E. coli, which encoded a polypeptide of 659 amino acids including two additional fragments: one 44 residues N-terminal fragment and another 193 residues C-terminal fragment. In order to investigate the role of the C-terminal fragment, two constructs with and without this region [BKAΔ(N44) and BKAΔ(N44C193)] were designed and expressed in E. coli BL21. The optimum pH, thermal stability, and the end-products of starch hydrolysis were found to be similar in both constructs. The Km and V(max) values for BKAΔ(N44) were lower than BKAΔ(N44C193), using either starch or ethylidene-blocked 4-nitrophenylmaltoheptaoside as a substrate. 相似文献
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Spániková A Simoncíková P Ravingerová T Pechánová O Barancík M 《Molecular and cellular biochemistry》2008,312(1-2):113-120
The aim of the present study was to characterize the effects of chronic nitric oxide synthase (NOS) inhibition on the alterations
of regulatory myocardial proteins of intracellular signaling pathways (mitogen-activated protein kinase (MAPK) and Akt kinase
cascades) and matrix metalloproteinases (MMP). Chronic NO deficiency (NOD) was induced by NG-nitro-L-arginine methyl ester (L-NAME, 40mg/kg/day, 4 weeks). Protein levels and activation of protein kinases were determined
using specific antibodies, activities of MMP were analyzed by zymography in gels containing gelatin as a substrate. The development
of NOD was associated with decreased activation of endothelial NOS (eNOS) and down-regulation of protein level of inducible
NOS (iNOS). Investigation of kinase pathways revealed that the activation of extracellular signal-regulated kinases (ERK)
and the levels of upstream activators of ERK (aFGF, H-Ras) were decreased after L-NAME treatment. Western blot analysis revealed
that chronic application of L-NAME also decreased the activation of Akt kinase as compared with control hearts. Study of MMPs
showed that in L-NAME-treated rat hearts activities of tissue MMP-2 were decreased. It is concluded that development of NOD
resulted in inhibition of ERK and Akt kinase pathways and these changes suggest the involvement of these cascades in responses
of myocardium to NOD. The results also point to the possible relationship between ERK and Akt kinase pathways and activation
of eNOS and/or MMP-2.
Anna Špániková and Petra Šimončíková have contributed equally to the study. 相似文献
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Mojtaba Tabatabaei Yazdi Younes Ghasemi Abdollah Ghasemian Shadman Shokravi Hossein Niknahad Mohsen Amini Ali Dehshahri Mohammad Ali Faramarzi 《World journal of microbiology & biotechnology》2005,21(6-7):811-814
Summary The bioconversion of hydrocortisone by a locally isolated strain of cyanobacterium Fischerella ambigua PTCC 1635 was investigated. Fischerella ambigua had not been previously examined for this potential. The fermentation led to production of 11β,17α, 20β, 21-tetrahydroxypregn-4-en-3-one and 11β-hydroxyandrost-4-en-3,17-dione. The metabolites were isolated and purified by chromatographic methods and identified using
instrumental analyses. 相似文献
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ATRIAL FIBRILLATION (AF) is the most common sustained dysrhythmia in adults. It is ironic, then, that although mechanisms and effective treatments for most other supraventricular tachyarrhythmias have been discovered, AF remains incompletely understood and poorly treated. Nonetheless, our understanding of the pathophysiology of AF has improved in the last half-century, including some groundbreaking observations made in the last 10 years. Indeed, for some patients, the potential for cure now appears to be available. Because no unifying mechanism of AF has been proven, the aim of this review is to describe some of the common and important concepts behind current mechanistic theories of AF and how they contribute to our clinical understanding of AF. 相似文献
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Mohammadjavad Fridoni PhD Reza Kouhkheil MSc Mohammad-Amin Abdollhifar PhD Abdollah Amini PhD Mahdi Ghatrehsamani PhD Seyed Kamran Ghoreishi PhD Sufan Chien Sahar Bayat Mohammad Bayat PhD 《Journal of cellular biochemistry》2019,120(6):9906-9916
We investigated the effects of photobiomodulation therapy (PBMT) and conditioned medium (CM) of human bone marrow mesenchymal stem cells (hBM-MSC) individually and/or in combination on the stereological parameters and the expression of basic fibroblast growth factor (bFGF), hypoxia-inducible factor (HIF-1α), and stromal cell–derived factor-1α (SDF-1α) in a wound model infected with methicillin-resistant Staphylococcus aureus (MRSA) in diabetic rats. CM was provided by culturing hBM-MSCs. Type 1 diabetes mellitus (T1DM) was induced in 72 rats, divided into four groups, harboring 18 rats each: group 1 served as a control group, group 2 received PBMT, group 3 received CM, and group 4 received CM + PBMT. On days 4, 7, and 15, six animals from each group were euthanized and the skin samples were separated for stereology examination and gene expression analysis by real-time polymerase chain reaction. In the CM + PBMT, CM, and PBMT groups, significant decreases were induced in the number of neutrophils (1460 ± 93, 1854 ± 138, 1719 ± 248) and macrophages (539 ± 69, 804 ± 63, 912 ± 41), and significant increases in the number of fibroblasts (1073 ± 116, 836 ± 75, 912 ± 41) and angiogenesis (15 230 ± 516, 13 318 ± 1116, 14 041 ± 867), compared with those of the control group (2690 ± 371, 1139 ± 145, 566 ± 90, 12 585 ± 1219). Interestingly, the findings of the stereological examination in the CM + PBMT group were statistically more significant than those in the other groups. In the PBMT group, in most cases, the expression of bFGF, HIF-1α, and SDF-1α, on day 4 (27.7 ± 0.14, 28.8 ± 0.52, 27.5 ± 0.54) and day 7 (26.8 ± 1.4, 29.6 ± 1.4, 28.3 ± 1.2) were more significant than those in the control (day 4, 19.3 ± 0.42, 25.5 ± 0.08, 22.6 ± 0.04; day 7, 22.3 ± 0.22, 28.3 ± 0.59, 24.3 ± 0.19) and other treatment groups. The application of PBMT + CM induced anti-inflammatory and angiogenic activities, and hastened wound healing process in a T1 DM model of MRSA infected wound. 相似文献
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Behnam Sadeghi Elham Roshandel Ali Pirsalehi Sepide Kazemi Ghazaleh Sankanian Mohammad Majidi Maryam Salimi Nasser Aghdami Hoda Sadrosadat Sarvenaz Samadi Kochaksaraei Farshid Alaeddini Olle Ringden Abbas Hajifathali 《Journal of cellular and molecular medicine》2021,25(22):10554-10564
Acute respiratory distress syndrome (ARDS) is the most common cause of death in COVID-19 patients. The cytokine storm is the main driver of the severity and magnitude of ARDS. Placenta-derived decidua stromal cells (DSCs) have a stronger immunosuppressive effect than other sources of mesenchymal stromal cells. Safety and efficacy study included 10 patients with a median age of 50 (range 14–68) years with COVID-19-induced ARDS. DSCs were administered 1–2 times at a dose of 1 × 106/kg. End points were safety and efficacy by survival, oxygenation and effects on levels of cytokines. Oxygenation levels increased from a median of 80.5% (range 69–88) to 95% (range 78–99) (p = 0.012), and pulmonary infiltrates disappeared in all patients. Levels of IL-6 decreased from a median of 69.3 (range 35.0–253.4) to 11 (range 4.0–38.3) pg/ml (p = 0.018), and CRP decreased from 69 (range 5–169) to 6 (range 2–31) mg/ml (p = 0.028). Two patients died, one of a myocardial infarction and the other of multiple organ failure, diagnosed before the DSC therapy. The other patients recovered and left the intensive care unit (ICU) within a median of 6 (range 3–12) days. DSC therapy is safe and capable of improving oxygenation, decreasing inflammatory cytokine level and clearing pulmonary infiltrates in patients with COVID-19. 相似文献
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Leonurus cardiaca is well known for its medicinal importance. In this investigation, genotypic characterization of this species from six eco-geographical regions of Iran was evaluated by four molecular techniques (AFLP, RAPD, ISSR and IRAP). A total of 899 polymorphic fragments were detected by used molecular markers (AFLP = 356, RAPD = 325, ISSR = 113 and IRAP = 105) with an overall average polymorphism of 81.24 %. Genetic variation calculated using Shannon’s Information index (I) and Nei’s gene diversity index (H) showed high genetic diversity in studied germplasm. Also, analysis of molecular variance showed high genetic variation among (55 %) and within populations (45 %). UPGMA dendrogram constructed from combined data of molecular markers distinguished studied populations in accordance with the results obtained by each marker which all individuals were clearly differentiated into two major clusters. The correlation coefficients were statistically significant for all marker systems with the highest correlation between similarity matrixes of RAPD and ISSR markers (r = 0.82). The present results have an important implication for L. cardiaca germplasm characterization, improvement, and conservation. Furthermore, the characterized individuals exhibited a great deal of molecular variation and they seem to have a rich gene pool for breeding programs. 相似文献