93 research outputs found
Intrauterine growth restriction and placental angiogenesis
Background: Vascular endothelial growth factor (VEGF), basic-fibroblast growth factor (b-FGF), and endothelial nitric oxide synthase (eNOS) are factors that take part in placental angiogenesis. They are highly expressed during embryonic and fetal development, especially in the first trimester. In this study, we aimed to investigate the role of placental angiogenesis in the development of intrauterine growth restriction (IUGR) by comparing the levels of expression of VEGF-A, b-FGF, and eNOS in normal-term pregnancy and IUGR placentas.Methods: The expression of VEGF-A, b-FGF, and eNOS was studied using the avidin-biotin-peroxidase method in placental tissues diagnosed as normal (n = 55) and IUGR (n = 55). Results were evaluated in a semi-quantitative manner.Results: The expression of all the markers was significantly higher (p < 0.001) in cytotrophoblasts, syncytiotrophoblasts, extravillous trophoblasts, vascular smooth muscle cells, chorionic villous stromal cells, and villous vascular endothelial cells of the IUGR placentas when compared with those collected from normal-term pregnancies.Conclusion: Increased expression of VEGF-A, b-FGF, and eNOS may be the result of inadequate uteroplacental perfusion, supporting the proposal that abnormal angiogenesis plays a role in the pathophysiology of IUGR. © 2010 Barut et al; licensee BioMed Central Ltd
Exo-π-bonding to an ortho-carborane hypercarbon atom: systematic icosahedral cage distortions reflected in the structures of the fluoro-, hydroxy- and amino-carboranes, 1-X-2-Ph-1,2-C 2
Adhesion and proliferation of living cell on surface functionalized with glycine nanostructures
This research presents the application of glycine amino acid for establishing firm cell-substrate interaction instead of expensive adhesion proteins, peptides and peptide derivatives. The glycine amino acid is chemically functionalized on the coverslip to achieve self-assembled nanostructure. Glycine self-assembly on NaCl treated coverslips is initiated with SiONa+:COO− linkage while their nanostructure is achieved with formation of glycine chain through NH3+:COO− covalent linkage between the adjacent molecules. The functionalization steps are confirmed by Fourier-transform infrared spectroscopy (FTIR) investigation. The atomic force microscopy (AFM) and scanning electron microscopy (SEM) investigations reveal that glycine growth initiates at 4 Hours (H) post-treatment while maximum growth appears after 8H-10H. Both the vertical and horizontal growth of nanostructures show dependence on functionalization periods. Various levels of glycine functionalized surface show different levels of baby hamster kidney (BHK-21) cell adhesion and proliferation efficiency with maximum performance for 10H functionalized surface. The adhesion and proliferation performance of 10H glycine functionalized surface shows negligible difference when compared with glycine-aspartic acid (RGD) functionalized surface. Finally, growth curves obtained from both glycine and RGD functionalized surface reveal exponential growth phage up to 48H followed by stationary phage between 48H and 72H while death of many cells appears from 72H to 96H. Thus, this research concluded that glycine functionalized surface is equally effective for cell adhesion and proliferation
Enhanced osteogenesis of human mesenchymal stem cells by self-assembled peptide hydrogel functionalized with glutamic acid templated peptides
PubMed: 32615018Self-assembling peptide (SAP) hydrogel has been shown to be an excellent biological material for three-dimensional cell culture and stimulatie cell migration and differentiation into the scaffold, as well as for repairing bone tissue defects. Herein, we designed one of the SAP scaffolds KLD (KLDLKLDLKLDL) through direct coupling to short bioactive motif O1 (EEGGC) and O2 (EEEEE) of which bioactivity on osteogenic differentiation was previously demonstrated and self-assembled in different concentrations (0.5%, 1%, and 2%). Our aim was to enhance osteogenesis and biomineralization of injectable SAP hydrogels with controlled mechanical properties so that the peptide hydrogel also becomes capable of being injected to bone defects. The molecular integration of the nanofibrous peptide scaffolds was observed using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The rheological properties and degradation profile of SAP hydrogels were evaluated to ensure stability of SAPs. Compared with pure KLD scaffold, we found that these designed bioactive peptide scaffolds significantly promoted hMSCs proliferation depicted by biochemical analysis of alkaline phosphatase (ALP) activity, total calcium deposition. Moreover, key osteogenic markers of ALP activity, collagen type I (COL-1), osteopontin (OP), and osteocalcin (OCN) expression levels determined by real-time polymerase chain reaction (PCR) and immunofluorescence analysis were also significantly increased with the addition of glutamic acid residues to KLD. We demonstrated that the designed SAP scaffolds promoted the proliferation and osteogenic differentiation of hMSCs. Our results suggest that these designed bioactive peptide scaffolds may be useful for promoting bone tissue regeneration. © 2020 John Wiley & Sons, Ltd.Türkiye Bilimsel ve Teknolojik Araştirma Kurumu, TÜBITAK: 117S429Authors acknowledge funding from T?B?TAK (The Scientific and Technological Research Council of Turkey) through the Research Project 117S429
Classic Kaposi sarcoma with sarcoid-like granulomas: a case report and review of the literature
27th International Congress of the International-Academy-of-Pathology -- OCT 12-17, 2008 -- Athens, GREECEWOS: 000259524800907Int Acad Patho
Ovarian heterotopic pregnancy clinically mimicking endometrioma: histopathological and immunohistochemical features
27th International Congress of the International-Academy-of-Pathology -- OCT 12-17, 2008 -- Athens, GREECEWOS: 000259524800452Int Acad Patho
Classic Kaposi sarcoma with sarcoid-like granulomas: A case report and literature review
The occurrence of granulomatous reactions within lymph nodes that drain carcinomas is well known but uncommon. Even more rarely, granulomas may occur within the stroma of tumors. These lesions, called sarcoid-like reactions, commonly accompany carcinomas but are very rare in sarcomas. This study presents a case of classic Kaposi sarcoma that contained sarcoid-like granulomas, with a literature review. A soft tissue lesion of the foot was excised from a 74-year-old male. Histopathological examination showed that the tumor tissue consisted of spindle cells, areas of atypical vascular proliferation, and extravasated erythrocytes surrounded by non-caseating granulomas. The patient had no clinical or laboratory findings of sarcoidosis. The case was interpreted as "Kaposi sarcoma containing sarcoid-like granulomas". The association of soft tissue sarcomas with a granulomatous reaction is very rare. A granulomatous reaction is reported to be a good prognostic indicator in several carcinoma types, although its importance in sarcomas is unclear. © 2009 Elsevier Inc. All rights reserved
Role of functionalized self-assembled peptide hydrogels inin vitrovasculogenesis
Fabrication of vascularized tissue constructs plays an integral role in creating clinically relevant tissues. Scaffold materials should be sufficiently vascularized to mimic functional and complex native tissues. Herein, we report the development of bioactive and biomimetic self-assembled peptide (SAP) hydrogels that allow the rapid formation of a vascular structurein vitro. The KLDLKLDLKLDL (KLD peptide) SAP was functionalized with laminin derived peptides IKVAV (V1) and YIGSR (V2) through direct coupling to mimic the natural extracellular matrix (ECM) and human umbilical endothelial cells (HUVECs) and mesenchymal stem cells (MSCs) cultured in 0.5% and 1% SAP hydrogels organized into vascularized structures. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) images proved the molecular integration of the nanofibrous structure in SAP hydrogels. The stability of SAP hydrogels was confirmed by rheological and degradation measurements. Bioactive peptide scaffolds enhanced significantly HUVEC/hMSC proliferation depicted by MTT analysis compared to KLD. Furthermore, the real time quantitative polymerase chain reaction (rt-PCR) was performed to analyse vascular gene expressions such as platelet/endothelial cell adhesion molecule-1 (PECAM-1), von Willebrand factor (vWF), and vascular endothelial cadherin (VE-cadherin). The results indicated that the KLD-V2 hydrogel significantly induced vasculogenesis in hMSC/HUVEC co-culture compared to KLD-V1, Biogelx and KLD because YIGSR in KLD-V2 promoted cell population and ECM secretion by the interaction with cells and increased vasculogenesis. Overall, the designed SAP hydrogel represents an effective scaffold for vascularization of tissue constructs with useful tissue engineering applications. © The Royal Society of Chemistry 2021.Türkiye Bilimsel ve Teknolojik Araştirma Kurumu, TÜBITAK: 117S429The authors acknowledge funding from TÜBİTAK (The Scientific and Technological Research Council of Turkey) through the Research Project 117S429
Effect of the Geometric Inaccuracy in Multivariate Adaptive Regression Spline-based Inverse ECG Solution Approach
Spline-based approaches have been applied to inverse problems in several areas. If proper spline bases are chosen, dimension of the problem can be significantly reduced while increasing estimation accuracy and robustness of the inverse procedure. We proposed Multivariate Adaptive Regression Splines (MARS) based methods for the solution of the inverse electrocardiography (ECG) problem considering the temporal and spatial evolution of the epicardial potentials. Our model defines the spline functions in terms of spatial parameters based on the given epicardial surface geometry. Thus, any change in geometry can alter the constructed model for the purpose of obtaining an accurate estimate. In this study, we focused on the effects of the geometric model inaccuracies on the proposed MARS-based approach
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