Search

Objective: The goal of this research was to determine the influence of 4 weeks aerobic training on gene expression of tumor necrosis factor alpha (TNF-α), hypoxia-inducible factor-1 alpha (HIF-1α) and vascular endothelial growth factor (VEGF) in the cardiac tissue of diabetic rats. Materials and Methods: In an experimental study, 30 male wistar rats were partitioned into three groups (n=10), diabetic aerobic training, diabetic control and healthy control (n=10). Induction of type 2diabetes (T2DM) was done by intraperitoneal infusion of streptozotocin. The progressive aerobic training protocol entailed 4 weeks, 5 sessions per week running on treadmill at velocity of 20 m/min for 60 min. The gene expression of TNF-α, VEGF and HIF-1α were measured by real time & PCR. One way analysis of variance and bonferroni test were applied to analysis the data. The significant level was set at P-value< 0.05. Results: The results indicated that the aerobic training induced significant decrease in TNF-α mRNA (P-value< 0.001) and significant increase in HIF-1α mRNA (P-value< 0.001) and VEGF mRNA (P-value< 0.001) compared to diabetic control group. Conclusion: It appears that aerobic training with reduction of TNF-α issues an affirmative effect on angiogenesis, as a result, it improves diabetic cardiac.

Objective: The goal of this research was to determine the influence of 4 weeks aerobic training on gene expression of tumor necrosis factor alpha (TNF-α), hypoxia-inducible factor-1 alpha (HIF-1a) and vascular endothelial growth factor (VEGF) in the cardiac tissue of diabetic rats. Materials and Methods: In an experimental study, 30 male wistar rats were partitioned into three groups (n=10), diabetic aerobic training, diabetic control and healthy control (n=10). Induction of type 2diabetes (T2DM) was done by intraperitoneal infusion of streptozotocin. The progressive aerobic training protocol entailed 4 weeks, 5 sessions per week running on treadmill at velocity of 20 m/min for 60 min. The gene expression of TNF-α, VEGF and HIF-1α were measured by real time & PCR. One way analysis of variance and bonferroni test were applied to analysis the data. The significant level was set at P-value< 0.05. Results: The results indicated that the aerobic training induced significant decrease in TNF-α mRNA (P-value< 0.001) and significant increase in HIF-1α mRNA (P-value< 0.001) and VEGF mRNA (P-value< 0.001) compared to diabetic control group. Conclusion: It appears that aerobic training with reduction of TNF-α issues an affirmative effect on angiogenesis, as a result, it improves diabetic cardiac. [ABSTRACT FROM AUTHOR]

Posttranslational modifications of histone tails can alter chromatin structure and regulate gene transcription. While recent studies implicate the lysine/arginine protein methyltransferases in the regulation of genes for endothelial metabolism, the role of AMI-1 and AMI-5 compounds in angiogenesis remains unknown. Here, we show that global inhibition of arginine and lysine histone methyltransferases (HMTs) by AMI-5 induced an angiostatic profile in human microvascular endothelial cells and human umbilical vein endothelial cells. Based on FACS analysis, we found that inhibition of HMTs significantly affects proliferation of endothelial cells, by suppressing cell cycle progression in the G 0 /G 1 phase. Immunofluorescent studies of the endothelial cells replication pattern by 5-ethynyl-2′-deoxyuridine incorporation disclosed that AMI-5, and the arginine methyltransferase inhibitor AMI-1, induced heterochromatin formation and a number of nuclear abnormalities, such as formation of micronuclei (MNs) and nucleoplasmic bridges (NPBs), which are markers of chromosomal instability. In addition to the modification of the cell cycle machinery in response to AMIs treatment, also endothelial cells migration and capillary-like tube formation processes were significantly inhibited, implicating a stimulatory role of HMTs in angiogenesis. [ABSTRACT FROM AUTHOR]

Tissue engineering is a rapidly growing field of research for several decades, which is driven by the human urgent need for tissue substitutes and transplantable organs. Considering the advancements, the clinical applications in the field of tissue engineering have been limited until now. The major reason toward this limitation is the lack of sufficient blood supply for the tissue in the earliest phase after implantation. Time-consuming process of angiogenesis leads to inadequate vascularization and finally, death of cells and destruction of tissue. During recent years, by implementing a strategy called Inosculation, it has been tried to facilitate tissue vascularization by a preformed vasculature network within tissue structure. In the current research considering cellular nature of angiogenesis process, relying on a cell-based mathematical model, the effect of inosculation strategy is investigated through the dynamics of angiogenesis process with respect to extracellular, cellular and intracellular spatio-temporal scales. The results show the advantages of inosculation strategy over angiogenesis strategy in vascularization of tissue constructs. The model demonstrates the capability of inosculation strategy to improve the anastomosis probability, which is providing the crucial requisite for the blood to flow through capillary network. Furthermore, the cellular model was developed in a way that illustrates the effects of extracellular matrix on morphogenesis through branching phenomenon. [ABSTRACT FROM AUTHOR]

• Multiscale model for the angiogenesis process, containing the lumen formation mechanism. • Investigating stochastic behavior of lumen expansion and the critical role of blood pressure and topology of blebs in bleb retraction. Cancer is one of the leading causes of mortality and morbidity among people worldwide. Cancer appears as solid tumors in many cases. Angiogenesis is the growth of blood vessels from the existing vasculature and is one of the imperative processes in tumor growth. Another vital phenomenon for formation and functionality of this vasculature network is lumen formation. The results of recent studies indicate the importance of blood pressure in this mechanism. Computational modeling can study these processes in different scales. Hence, wide varieties of these models have been proposed during recent years. In this research, a multi-scale model is developed for the angiogenesis process. In the extracellular scale, the growth factor concentration is calculated via the reaction diffusion equation. At the cellular scale, growth, migration, and the adhesion of endothelial cells are modeled by the Potts cellular model. At the intra-cellular scale by considering biochemical signals, a Boolean network model describes migration, division, or apoptosis of endothelial cells. A stochastic model developed for lumen formation via inverse membrane blebbing mechanism. A CFD simulation was also used to investigate the role of pulsated blood pressure in the inverse membrane blebbing mechanism. The lumen formation model shows stochastic behavior in blebs expansion and lumen expansion. Comparing the stochastic model's results with the CFD simulation also shows the vital role of pressure pulse and the topology of the blebs in bleb retraction. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a strategy for segmenting blood vessels based on the threshold, which combines statistics and scale space filter. By incorporating statistical information, the strategy is capable of reducing over-segmentation. We propose a two-stage strategy which involves: (1) optimal selection of window size and (2) optimal selection of scale. We compared our strategy to two commonly used thresholding techniques. Experimental results showed that our method is much more robust and accurate. Our strategy suggested a modification to Otsu''s method. In this application the important information to be extracted from images is only the number of blood vessels present in the images. The proposed segmentation technique is tested on manual segmentation, where segmentation errors less than 3% were observed. The work presented in this paper is a part of a global image analysis process. Therefore, these images will be subject to a further morphometrical analysis in order to diagnose and predict automatically malign tumors. [Copyright &y& Elsevier]

Abstract: The watersheds method is a powerful segmentation tool developed in mathematical morphology. In order to prevent its over-segmentation, in this paper, we present a new strategy to obtain robust markers for segmentation of blood vessels from malignant tumors. For this purpose, we introduced a new algorithm. We propose a two-stage segmentation strategy which involves: (1) extracting an approximate region containing the blood vessel and part of the background near the blood vessel, and (2) segmenting the blood vessel from the background within this region. The approach effectively reduces the influence of peripheral background intensities on the extraction of a blood vessel region. In this application the important information to be extracted from images is only the number of blood vessels present in the images. The proposed strategy was tested on manual segmentation, where segmentation errors less than 10% for false positives and 0% for false negatives are observed. It is demonstrated by extensive experimentation, by using real images, that the proposed strategy was suitable for our application in the environment of a personal computer. [Copyright &y& Elsevier]

Simple Summary: Angiogenesis is an essential event for the progression of solid tumors and is promoted by angiogenic cytokines released in the tumor microenvironment by neoplastic and stromal cells. Over the last 20 years, the role of the microenvironment and the implication of several angiogenic factors in tumorigenesis of solid and hematological neoplasms have been widely studied. The tumor microenvironment has also been well-defined for thyroid cancer, clarifying the importance of angiogenesis in cancer progression, spread, and metastasis. Furthermore, recent studies have evaluated the association of circulating angiogenic factors with the clinical outcomes of differentiated thyroid cancer, potentially providing noninvasive, low-cost, and safe tests that can be used in screening, diagnosis, and follow-up. In this review, we highlight the mechanisms of action of these proangiogenic factors and their different molecular pathways, as well as their applications in the treatment and prognosis of thyroid cancer. Thyroid cancer is the most common endocrine malignancy, with a typically favorable prognosis following standard treatments, such as surgical resection and radioiodine therapy. A subset of thyroid cancers progress to refractory/metastatic disease. Understanding how the tumor microenvironment is transformed into an angiogenic microenvironment has a role of primary importance in the aggressive behavior of these neoplasms. During tumor growth and progression, angiogenesis represents a deregulated biological process, and the angiogenic switch, characterized by the formation of new vessels, induces tumor cell proliferation, local invasion, and hematogenous metastases. This evidence has propelled the scientific community's effort to study a number of molecular pathways (proliferation, cell cycle control, and angiogenic processes), identifying mediators that may represent viable targets for new anticancer treatments. Herein, we sought to review angiogenesis in thyroid cancer and the potential role of proangiogenic cytokines for risk stratification of patients. We also present the current status of treatment of advanced differentiated, medullary, and poorly differentiated thyroid cancers with multiple tyrosine kinase inhibitors, based on the rationale of angiogenesis as a potential therapeutic target. [ABSTRACT FROM AUTHOR]