Showing 5 results for Extracellular
Asgarani F, Khajeali L, Esfahanian F, Vosogh Mh, Esteghamati Ar, Nakhjavani M,
Volume 67, Issue 9 (12-2009)
Abstract
Background: Increased rate of oxidative stress have important role in diabetic nephropathy. Oxidative stress induces the synthesis of antioxidant enzymes. One of them, Extracellular- SOD (EC–SOD) is a major anti-oxidative enzyme and the only one that neutralizes superoxide ion, a precursor of reactive oxygen species (ROS). The aim of this study was to evaluate the correlation between diabetes- associated oxidative stress and antioxidative defense in macroalbuminuric type 2 diabetic patients.
Methods: One hundred and thirty three patients (74 women, 59 men) with type 2 diabetes were studied during 1385-86. According to level of urinary protein, two groups of patients normoalbuminuric (urinary protein excertion below 30mg/24h) and macroalbuminuric (urinary protein excretion more than 300mg/24) were recognized. In each group serum level of oxidized- LDL and EC-SOD were measured.
Results: The mean age of patients and the mean duration of diabetes was 59.09±8.26 years and 137.92±65.91 months, respectively. The plasma oxidized-LDL level and extracellular- superoxide dimutase level were significantly higher in macroalbuminuric than normoalbuminuric group (88.57±33.36 versus 78.24±27.59u/l, p=0.039 for oxidized-LDL and 87.60±21.18 versus 76.25±16.25mu/l, p<0.001 for EC-SOD). Oxidized- LDL was significantly correlated to EC-SOD in macroalbuminuric patients (r=0.425, p<0.0001). Oxidized-LDL and EC-SOD does not correlate to Fasting Plasma Glucose and HbA1c in each two groups.
Conclusion: The significantly elevated plasma oxidized-LDL in patients with macroalbuminuria suggests that, oxidized-LDL may play an important role in the progression of diabetic nephropathy. Besides severity of oxidative stress in macroalbuminuic patients, increase level of EC-SOD enzyme could be a compensatory mechanism to prevent tissue damage.
Taghavi Kani M, Homayoon Jafari A, Khoshnevisan A, Arabalibeyk H, Abolhasani Mj,
Volume 68, Issue 11 (2-2011)
Abstract
Background: Studying the behavior of a society of neurons, extracting the communication mechanisms of brain with other tissues, finding treatment for some nervous system diseases and designing neuroprosthetic devices, require an algorithm to sort neuralspikes automatically. However, sorting neural spikes is a challenging task because of the low signal to noise ratio (SNR) of the spikes. The main purpose of this study was to design an automatic algorithm for classifying neuronal spikes that are emitted from a specific region of the nervous system.
Methods: The spike sorting process usually consists of three stages: detection, feature extraction and sorting. We initially used signal statistics to detect neural spikes. Then, we chose a limited number of typical spikes as features and finally used them to train a radial basis function (RBF) neural network to sort the spikes. In most spike sorting devices, these signals are not linearly discriminative. In order to solve this problem, the aforesaid RBF neural network was used.
Results: After the learning process, our proposed algorithm classified any arbitrary spike. The obtained results showed that even though the proposed Radial Basis Spike Sorter (RBSS) reached to the same error as the previous methods, however, the computational costs were much lower compared to other algorithms. Moreover, the competitive points of the proposed algorithm were its good speed and low computational complexity.
Conclusion: Regarding the results of this study, the proposed algorithm seems to serve the purpose of procedures that require real-time processing and spike sorting.
Arash Abdolmaleki , Mohammad Bagher Ghayour , Masoud Feridoni ,
Volume 73, Issue 5 (8-2015)
Abstract
Fibronectin (FN) is one of the essential component of the extra cellular matrix and their important role is as regulator of cellular activities and also fibronectin is an important scaffold for maintaining tissue. Fibronectin conformational changes expose additional binding sites that participate in fibril formation and in conversion of fibrils into a stabilized, insoluble form. In fact fibronectin is a connected glycoprotein disulfide dimer with sedimentation coefficient of approximately S 13 and 440 kDa molecular mass which is exist in many extracellular matrix and plasma with concentration of approximately 300 µg/ml that during the regeneration body tissues acts in severely regulated stages until regenerate the damaged tissue. Fibronectin has domains for interacting with other extra cellular matrix proteins, cell surface receptors, glycosaminoglycans (GAGs), and other FN molecules. This combination of domains allows FNs to bind simultaneously to cells and to molecules within the surrounding matrix. Also fibronectin have binding sites for collagen/ gelatin, heparin, fibrinogen, and other molecules. In the present study important roles of fibronectin in development, regeneration especially in nerves system and important role of it in treatment of some diseases have been reviewed. Present study has reviewed 77 publications by using of PubMed, NCBI, Elsevier, EBSCO and Nature databases for describing the important roles of fibronectin in biological systems. Studies have shown that fibronectin has diverse roles such as: cellular adhesion, embryonic differentiation, assembly of extra cellular matrix, connecting and cell growth, transformation as well as cell migration that each of this roles depends to fibronectins action site. Considering the important role of fibronectin in attachment of cancer cells to basal lamina, spread neoplasm, tissue regeneration and formation of extra cellular matrix better identification the properties as well as physiological applications of fibronectin in tissues and bodies of animals can provide the better understanding of physiological mechanisms and pathophysiological effects of cells on each other, and also provides the new ways for treatment a variety of diseases.
Arash Abdolmaleki, Mohammad-Bagher Ghayour, Saber Zahri, Asadollah Asadi , Morteza Behnam-Rassouli ,
Volume 77, Issue 2 (5-2019)
Abstract
Background: Tissue engineering is a developing multidisciplinary and interdisciplinary field involving the use of bioartificial implants for tissue remodeling with the target for repair and enhancing tissue or organ function. Acellular nerve has been used in experimental models as a peripheral nerve substitute. The purpose of the present study was to evaluate the mechanical and histological characteristics of acellular nerve scaffolds compared to the fresh nerve for application in environmental nerve repair.
Methods: This experimental study was conducted in Ferdowsi University of Mashhad Regeneration Research Laboratory, Mashhad, Iran, from May 2017 to October 2018. In this study for preparing the scaffold. The rats were sacrificed by intraperitoneal anesthesia with 10 % Chloral Hydrate solution. Then sciatic nerve fragments of the rats were removed above the nerve branching site and after cleansing of the tissues were decellularized by Sondell method, briefly nerves were treated with a series of detergent baths consisting of distilled water for 8 h, Triton X-100 for 12 h, and sodium deoxycholate for 24 hours according to the Sondell protocol. All acellularization steps were performed at room temperature. Then decellularized scaffolds were evaluated histologically and mechanically.
Results: The results of tissue evaluations showed that decellularization of scaffolds were done completely, this was demonstrated by hematoxylin and eosin staining and DAPI staining. Also the specialized tissue evaluations by picro-fuchsin staining and evaluation the scaffolds by scanning electron microscopy (SEM) micrographs showed that the collagen and elastin strands are relatively preserved in the extracellular matrix in comparison with control groups. As well as mechanical examination of scaffolds in tensile test showed that extracellular matrix of scaffolds was relatively preserved the main components of tissue compared to control group and scaffolds have good mechanical resistance quality for use in tissue engineering.
Conclusion: The results of the present study showed that decellularized scaffolds that prepared with Sondell decellularization method by preserving the main components of the tissue can be a good platform for investigating cellular behaviors.
Samira Shahraki , Mahmoud Tavakkoli, Abolfazl Khajavirad, Maryam Moghadam Matin , Mohammad Aslzare ,
Volume 82, Issue 1 (3-2024)
Abstract
Background: A range of diseases can result in end-stage renal disease (ESRD), characterized by a gradual decline in kidney function and associated with significant morbidity and mortality. Currently, renal transplantation as the most effective treatment for managing ESRD. Tissue engineering presents a considerable opportunity to expand the available supply of donor organs for kidney transplants. The aim of this research was to develop a suitable technique for preparing decellularized kidney scaffolds from human tissues.
Methods: The present study was carried out from April 2019 to August 2019 in Mashhad University of Medical Sciences. In this study, two decellularization protocols were compared using sections of human kidney tissue. Therefore, two human kidneys which collected from Ghaem and Imam Reza hospitals were used. In the first protocol, detergents such as 1% Triton X-100 (1A) and 1% SDS (Sodium Dodecyl Sulfate) (1B) were employed, followed by the application of DNase I. The second protocol utilized 0.5% SDS (2A) and 1% SDS (2B). The effectiveness of these techniques was evaluated using hematoxylin and eosin (H&E) staining, 4',6-diamidino-2-phenylindole (DAPI), DNA quantification, and immunohistochemistry (IHC).
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Results: Based on H&E staining results, comparison of the decellularized and native human kidney tissues showed a successful elimination of cell nuclei and the ameliorate extracellular matrix preservation in triton-treated scaffolds (1A) in comparison with the SDS-treated scaffolds (1B) at all times protocols. Furthermore, DNA quantification illustrated triton X-100 in removing DNA was more effective in eliminating DNA from kidney tissues compared to other protocols in renal tissues. In addition, IHC staining demonstrated that the expression of collagen IV and laminin was preserved throughout the decellularization process with Triton X-100 on day fifth. Also, IHC staining indicated human leukocyte antigen (HLA) was completely eliminated in the cortex-medulla of human scaffolds treated with Triton X-100 within day fifth.
Conclusion: Our results demonstrated that triton X-100 outperformed SDS as a detergent for decellularizing human kidneys. Meanwhile these results indicate suitable method for decellularization of human kidneys to produce functional kidneys.
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