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排序方式: 共有194条查询结果,搜索用时 234 毫秒
71.
Ebrahim Mostafavi Arash Aghajani Nargesi Zaniar Ghazizadeh Mehrdad Larry Roya Horabad Farahani Afsaneh Morteza Alireza Esteghamati Claude Vigneron Manouchehr Nakhjavani 《The Journal of membrane biology》2014,247(8):695-701
Calcium is a key regulator of cell dynamics. Dysregulation of its cytosolic concentration is implicated in the pathophysiology of several diseases. This study aimed to assess the effects of calcium on the network of membrane cytoskeletal proteins. Erythrocyte membranes were obtained from eight healthy donors and incubated with 250 µM and 1.25 mM calcium solutions. Membrane cytoskeletal proteins were quantified using SDS-PAGE at baseline and after 3 and 5 days of incubation. Supra-physiologic concentrations of calcium (1.25 mM) induced a significant proteolysis in membrane cytoskeletal proteins, compared with magnesium (p < 0.001). Actin exhibited the highest sensitivity to calcium-induced proteolysis (6.8 ± 0.3 vs. 5.3 ± 0.6, p < 0.001), while spectrin (39.9 ± 1.0 vs. 40.3 ± 2.0, p = 0.393) and band-6 (6.3 ± 0.3 vs. 6.8 ± 0.8, p = 0.191) were more resistant to proteolysis after incubation with calcium in the range of endoplasmic reticulum concentrations (250 µM). Aggregation of membrane cytoskeletal proteins was determined after centrifugation and was significantly higher after incubation with calcium ions compared with control, EDTA and magnesium solutions (p < 0.001). In a supra-physiologic range of 1.25–10 mM of calcium ions, there was a nearly perfect linear relationship between calcium concentration and aggregation of erythrocyte membrane cytoskeletal proteins (R 2 = 0.971, p < 0.001). Our observation suggests a strong interaction between calcium ions and membrane cytoskeletal network. Cumulative effects of disrupted calcium homeostasis on cytoskeletal proteins need to be further investigated at extended periods of time in disease states. 相似文献
72.
Conor Rossi Gabriela Ruß-Popa Valeria Mattiangeli Fionnuala McDaid Andrew J. Hare Hossein Davoudi Haeedeh Laleh Zahra Lorzadeh Roya Khazaeli Homa Fathi Matthew D. Teasdale Abolfazl A'ali Thomas Stllner Marjan Mashkour Kevin G. Daly 《Biology letters》2021,17(7)
Mummified remains have long attracted interest as a potential source of ancient DNA. However, mummification is a rare process that requires an anhydrous environment to rapidly dehydrate and preserve tissue before complete decomposition occurs. We present the whole-genome sequences (3.94 X) of an approximately 1600-year-old naturally mummified sheep recovered from Chehrābād, a salt mine in northwestern Iran. Comparative analyses of published ancient sequences revealed the remarkable DNA integrity of this mummy. Hallmarks of postmortem damage, fragmentation and hydrolytic deamination are substantially reduced, likely owing to the high salinity of this taphonomic environment. Metagenomic analyses reflect the profound influence of high-salt content on decomposition; its microbial profile is predominated by halophilic archaea and bacteria, possibly contributing to the remarkable preservation of the sample. Applying population genomic analyses, we find clustering of this sheep with Southwest Asian modern breeds, suggesting ancestry continuity. Genotyping of a locus influencing the woolly phenotype showed the presence of an ancestral ‘hairy’ allele, consistent with hair fibre imaging. This, along with derived alleles associated with the fat-tail phenotype, provides genetic evidence that Sasanian-period Iranians maintained specialized sheep flocks for different uses, with the ‘hairy’, ‘fat-tailed’-genotyped sheep likely kept by the rural community of Chehrābād''s miners. 相似文献
73.
Roya Jafarzadeh Samani Elahe Tajbakhsh Hassan Momtaz Mohsen Kabiri Samani 《Reports of Biochemistry & Molecular Biology》2021,10(1):50
Background:This study aims to specify the antimicrobial resistance pattern and virulence genes of Enterococcus faecalis isolated from urinary tract infections in Shahrekord, Iran. Methods:Urine samples of 1000 people suspected of having urinary tract infections referred to Shahrekord medical diagnostic laboratories were examined. Biofilm assays were performed by microtiter plate test through reading the OD490. Polymerase Chain Reaction (PCR) was applied to study the virulence factors.Results:Enterococcus faecalis was detected in 60 samples. After performing microbiological tests, all samples were positive in the molecular analysis. Strong, moderate and weak biofilm reactions reported 66.67%, 25%, and 8.33% respectively. The most resistance reported to cotrimoxazole, vancomycin and amikacin and the lowest resistance to nitrofurantoin (8.33%) was reported. Statistical analysis with Fisher''s exact test showed a statistically significant relationship between biofilm production and resistance to cotrimoxazole, vancomycin and cefotaxime. Prevalence of efe A, ace, gel E, esp, cyl M, agg, cyl A and cyl B in strong biofilm formation isolates was reported 100%, 87.5%, 82%, 62.5%, 55%, 37.5% 25% and 22.5% respectively. There was a significant relationship between the frequency of efa A and strong biofilm reaction.Conclusion:The presence of E. faecalis strains resistant to co-trimoxazole and vancomycin and present of some virulence factors is alarming the researchers. Since antibiotic resistance genes are probably transmitted among enterococci, and Staphylococci, controlling infections made by enterococci as well as the appropriate administration of antibiotics could treat the nosocomial infections effectively.Key Words: Antibiotic Resistance, Enterococcus faecalis, Urinary Tract Infection, Virulence genes 相似文献
74.
The relative suitability of four plants was studied for larvae of Pieris rapae L. and its parasitoid Cotesia rubecula (Marshall). For unparasitized P. rapae, pupal dry weight and egg-pupa growth rate were higher on cabbage, radish and nasturtium than on Indian hedge mustard. Larval developmental rate and size were greatest for C. rubecula when its host was feeding on nasturtium. Wasp survival was not affected by the host insect/plant combination in which the parasitoid developed. These results indicate that the plant on which host larvae feed is an important factor in development of the parasitoid. 相似文献
75.
76.
Regulation of tumor angiogenesis by thrombospondin-1 总被引:8,自引:0,他引:8
Angiogenesis plays a critical role in the growth and metastasis of tumors. Thrombospondin-1 (TSP-1) is a potent angiogenesis inhibitor, and down-regulation of TSP-1 has been suggested to alter tumor growth by modulating angiogenesis in a variety of tumor types. Expression of TSP-1 is up-regulated by the tumor suppressor gene, p53, and down-regulated by oncogenes such as Myc and Ras. TSP-1 inhibits angiogenesis by inhibiting endothelial cell migration and proliferation and by inducing apoptosis. In addition, activation of transforming growth factor beta (TGF-beta) by TSP-1 plays a crucial role in the regulation of tumor progression. An understanding of the molecular basis of TSP-1-mediated inhibition of angiogenesis and tumor progression will aid in the development of novel therapeutics for the treatment of cancer. 相似文献
77.
A modification of the iodometric technique using an overlay gel was employed for fast identification and isolation of beta-lactamase types TEM, SHV and AmpC from non-denaturing gels. Osmotic shock preparations of the three beta-lactamases were run on polyacrylamide gels without SDS and ampicillin containing overlay gels were flooded with the iodine solution before being placed on polyacrylamide gel strips. Distinct clear bands appeared in dark blue backgrounds indicating beta-lactamase activity. 相似文献
78.
CE Henderson-Toth ED Jahnsen R Jamarani S Al-Roubaie EA Jones 《Developmental biology》2012,369(2):330-339
The glycocalyx, and the thicker endothelial surface layer (ESL), are necessary both for endothelial barrier function and for sensing mechanical forces in the adult. The goal of this study is to use a combination of imaging techniques to establish when the glycocalyx and endothelial surface layer form during embryonic development and to determine the biological significance of the glycocalyx layer during vascular development in quail embryos. Using transmission electron microscopy, we show that the glycocalyx layer is present as soon as blood flow starts (14 somites). The early endothelial glycocalyx (14 somites) lacks the distinct hair-like morphology that is present later in development (17 and 25 somites). The average thickness does not change significantly (14 somites, 182nm±33nm; 17 somites, 218±30nm; 25 somites, 212±32nm). The trapping of circulating fluorescent albumin was used to evaluate the development of the ESL. Trapped fluorescent albumin was first observed at 25 somites. In order to assess a functional role for the glycocalyx during development, we selectively degraded luminal glycosaminoglycans. Degradation of hyaluronan compromised endothelial barrier function and prevented vascular remodeling. Degradation of heparan sulfate down regulated the expression of shear-sensitive genes but does not inhibit vascular remodeling. Our findings show that the glycocalyx layer is present as soon as blood flow starts (14 somites). Selective degradations of major glycocalyx components were shown to inhibit normal vascular development, examined through morphology, vascular barrier function, and gene expression. 相似文献
79.
Osteoblasts are a key component of the endosteal hematopoietic stem cell niche and are recognized with strong hematopoietic supporting activity. Similarly, mesenchymal stromal cells (MSC)‐derived osteoblast (M‐OST) conditioned media (OCM) enhance the growth of hematopoietic progenitors in culture and modulate their engraftment activity. This article aims to characterize the hematopoietic supporting activity of OCM by comparing the secretome of M‐OST to that of their precursor. Over 300 proteins are quantified by mass spectroscopy in media conditioned with MSC or M‐OST, with 47 being differentially expressed. Growth factors, extracellular matrix proteins, and proteins from the complement pathways are included. The functional contribution of selected proteins on the growth and differentiation of cord blood (CB) progenitors is tested. Secreted protein acidic and rich in cysteine and Galectin 3 (Gal3) have little impact on the growth of CB cells in serum‐free medium (SFM). In contrast, inhibition of the complement 3A receptor (C3a‐R) present on CB progenitors significantly reduces the growth of CD34+ cells in OCM cultures but not in SFM. These results provide new insights into changes in factors released by MSC undergoing osteoblast differentiation, and on paracrine factors that are partially responsible for the hematopoietic supporting activity of osteoblasts. 相似文献
80.
Razavizadeh Roya Adabavazeh Fatemeh Komatsu Setsuko 《Journal of plant biochemistry and biotechnology.》2020,29(3):473-483
Journal of Plant Biochemistry and Biotechnology - Chitosan is a natural nontoxic biopolymer, which is indicated as an aid for reducing oxidative injury caused by salt stress. To explore the... 相似文献