Characteristics Of Blood Vessels Research Articles

Hyaluronan Receptor LYVE-1-Expressing Macrophages Maintain Arterial Tone through Hyaluronan-Mediated Regulation of Smooth Muscle Cell Collagen

The maintenance of appropriate arterial tone is critically important for normal physiological arterialfunction. However, the cellular and molecular mechanisms remain poorly defined. Here, we have shown that in the mouse aorta, resident macrophages prevented arterial stiffness and collagen deposition in the steady state. Using phenotyping, transcriptional profiling, and targeted deletion of Csf1r, we have demonstrated that thesemacrophages-which are a feature of blood vessels invested with smooth muscle cells (SMCs) in both mouse and human tissues-expressed the hyaluronan (HA) receptor LYVE-l. Furthermore, we have shown they possessed the unique ability to modulate collagen expression in SMCs by matrix metalloproteinase MMP-9-dependent proteolysis through engagement of LYVE-1 with the HA pericellular matrix of SMCs. Our studyhas unveiled a hitherto unknown homeostatic contribution of arterial LYVE-1+ macrophages through the control of collagen production by SMCs and has identified a function of LYVE-1 in leukocytes.

Engineering biofunctional in vitro vessel models using a multilayer bioprinting technique

Recent advances in the field of bioprinting have led to the development of perfusable complex structures. However, most of the existing printed vascular channels lack the composition or key structural and physiological features of natural blood vessels or they make use of more easily printable but less biocompatible hydrogels. Here, we use a drop-on-demand bioprinting technique to generate in vitro blood vessel models, consisting of a continuous endothelium imitating the tunica intima, an elastic smooth muscle cell layer mimicking the tunica media, and a surrounding fibrous and collagenous matrix of fibroblasts mimicking the tunica adventitia. These vessel models with a wall thickness of up to 425 µm and a diameter of about 1 mm were dynamically cultivated in fluidic bioreactors for up to three weeks under physiological flow conditions. High cell viability (>83%) after printing and the expression of VE-Cadherin, smooth muscle actin, and collagen IV were observed throughout the cultivation period. It can be concluded that the proposed novel technique is suitable to achieve perfusable vessel models with a biofunctional multilayer wall composition. Such structures hold potential for the creation of more physiologically relevant in vitro disease models suitable especially as platforms for the pre-screening of drugs.

RETINA BASED BIOMETRIC AUTHENTICATION SYSTEM: A REVIEW

A biometric system provides an automatic person authentication based on some characteristic features possessed by the individual. Among all other biometrics, the retinal biometric system is unique as well as stable. The retina is a secure and reliable source of person recognition as it lies behind the eye and is unforgeable. The process of recognition mainly includes pre-processing, feature extraction and then feature matching. The features generally used in this process are either blood vessel features or non-blood vessel features. In this paper, different methods available in the literature for retina based person authentication system are described, discussed and compared.

Label-free photoacoustic imaging of human palmar vessels: a structural morphological analysis

We analysed the vascular morphology of the palm using a photoacoustic tomography (PAT) instrument with a hemispherical detector array. The three-dimensional (3D) morphology of blood vessels was determined noninvasively. Overall, 12 females and 11 males were recruited as healthy volunteers. Their ages were distributed almost evenly from 22 to 59 years. In all cases, many vascular networks were observed just beneath the skin and were determined to be veins anatomically. To analyse the major arteries, the layer containing the subcutaneous venous network was removed from the image. The analysis focused on the common and proper palmar digital arteries. We used the curvature of these arteries as a parameter to analyse their morphologies. There was no significant difference in the curvature between genders when comparing the subjects as a whole. The blood vessel curvature increased with age. Good agreement was found between the 3D numerical analysis results and the subjective evaluation of the two-dimensional (2D) projection image. The PAT system enabled visualization of the 3D features of blood vessels in the palm and noninvasive analysis of arterial tortuousness.

Robust retinal blood vessel segmentation using line detectors with multiple masks

Several diseases can be detected and diagnosed at a very early stage by observing changes in retinal blood vessel features. In order to detect these changes, the major step required is blood vessel segmentation. In this study, an effective method for the segmentation of blood vessels on coloured digital retinal images has been proposed. The proposed method uses linear combination of line detectors at varying scales along with multiple windows of different sizes. By implementing this technique, the drawbacks encountered in multi-scale line detection such as noise and false vessel detection around the optic disk are eliminated. The performance of the proposed method is evaluated on three publicly available datasets DRIVE, STARE and CHASE by considering sensitivity, specificity, accuracy, precision, false discovery rate, F1 score, Matthews correlation coefficient and G-mean. The results were analysed by comparing with most of the other earlier existing methods and have proven to achieve higher accuracy. It has also confirmed its effectiveness and robustness with high-resolution retinal images together with better simplicity and faster implementation for reliable blood vessel segmentation.

Optic Disc Localization Combining Improved Graph Based Visual Saliency Model and Distribution Feature of Retinal Blood Vessels

Optic Disc Localization Combining Improved Graph Based Visual Saliency Model and Distribution Feature of Retinal Blood Vessels

Adaptive Eye Fundus Vessel Classification for Automatic Artery and Vein Diameter Ratio Evaluation

Eye fundus imaging is a useful, non-invasive tool in disease progress tracking, in early detection of disease and other cases. Often, the disease diagnosis is made by an ophthalmologist and automatic analysis systems are used only for support. There are several commonly used features for disease detection, one of them is the artery and vein ratio measured according to the width of the main vessels. Arteries must be separated from veins automatically in order to calculate the ratio, therefore, vessel classification is a vital step. For most analysis methods high quality images are required for correct classification. This paper presents an adaptive algorithm for vessel measurements without the necessity to tune the algorithm for concrete imaging equipment or a specific situation. The main novelty of the proposed method is the extraction of blood vessel features based on vessel width measurement algorithm and vessel spatial dependency. Vessel classification accuracy rates of 0.855 and 0.859 are obtained on publicly available eye fundus image databases used for comparison with another state of the art algorithms for vessel classification in order to evaluate artery-vein ratio ($AVR$). The method is also evaluated with images that represent artery and vein size changes before and after physical load. Optomed OY digital mobile eye fundus camera Smartscope M5 PRO is used for image gathering.

Retinal disease diagnosis by morphological feature extraction and SVM classification of retinal blood vessels

Retinal vessel segmentation is an important division of automated retinal disease screening systems. The morphological variations of the retinal blood vessels correspond with the chances of cardiovascular and other related diseases. The incorrect detection of the blood vessels because of the misclassifications get reflected in the measurement results and results in the physicians advising incorrect strategies of diagnosis. In the same way, the pharmaceutical experts who prepare the drugs for diagnosis and medicines might be misdirected by this problem of misclassification. The available vessel segment graph doesn’t help in eliminating the Optic Disc (OD) boundary there by causing OD pixels misdetection, which intersects with the blood vessels. Therefore in the earlier work, the OD segmentation is carried outmaking use of discrete anisotropic filter and Particle Swarm Optimization whereas Fuzzy Neural Network (FNN) classifier has been utilized for blood vessel segmentation. But, the morphological variations are not detected accurately without an efficient feature extraction and selection process. Therefore in this work, the extraction of the geometric properties of blood vessel features are carried outmaking use of Grey Level Co-occurrence Matrix (GLCM) and the feature selection is conducted employing Mutual Information and Naive Bayesian Classifier. In this work, the noise elimination is performed applying Modified Kalman filter with image enhancement making use of the Hybrid PCA technique. The OD segmentation process is improved by using the Discrete Anisotropic Filter and Bee colony algorithm. At last, the classification of the true blood vessels is done by making use of SVM classifier. Therefore the retinal blood vessels are accurately classified considering the morphological changes that can be noticed from the experimental results. Therefore this technique yields an effective platform for suitable medicinal preparation and a precise diagnosis of retinal diseases.

Coexistence of Eph receptor B1 and ephrin B2 in port-wine stain endothelial progenitor cells contributes to clinicopathological vasculature dilatation.

Port-wine stain (PWS) is a vascular malformation characterized by progressive dilatation of postcapillary venules, but the molecular pathogenesis remains obscure. To illustrate that PWS endothelial cells (ECs) present a unique molecular phenotype that leads to pathoanatomical PWS vasculatures. Immunohistochemistry and transmission electron microscopy were used to characterize the ultrastructure and molecular phenotypes of PWS blood vessels. Primary culture of human dermal microvascular endothelial cells and in vitro tube formation assay were used for confirmative functional studies. Multiple clinicopathological features of PWS blood vessels during the development and progression of the disease were shown. There were no normal arterioles and venules observed phenotypically and morphologically in PWS skin; arterioles and venules both showed differentiation impairments, resulting in a reduction of arteriole-like vasculatures and defects in capillary loop formation in PWS lesions. PWS ECs showed stemness properties with expression of endothelial progenitor cell markers CD133 and CD166 in non-nodular lesions. They also expressed dual venous/arterial identities, Eph receptor B1 (EphB1) and ephrin B2 (EfnB2). Co-expression of EphB1 and EfnB2 in normal human dermal microvascular ECs led to the formation of PWS-like vasculatures in vitro, for example larger-diameter and thick-walled capillaries. PWS ECs are differentiation-impaired, late-stage endothelial progenitor cells with a specific phenotype of CD133+ /CD166+ /EphB1+ /EfnB2+ , which form immature venule-like pathoanatomical vasculatures. The disruption of normal EC-EC interactions by coexistence of EphB1 and EfnB2 contributes to progressive dilatation of PWS vasculatures.

ID:4006 Advanced Nanotechnologies for Cancer Research

In this lecture, I will discuss the recent developments in our group in the advanced optical imaging systems, nanocarriers and nanodevices for caner research. I will first discuss the development of various nanoparticles for sensing the pH value in cellular environment. By surface functionalization schemes, it is possible to control the location of nanoparticles in cells allowing us to track the local pH value around the nanoparticles inside cancer cells. As for in vivo study, we have utilized the multi-photon microscopy to investigate the disease models with the help of nanoparticles. I will discuss the enhanced permeability and retention (EPR) effect, which is a key feature of tumor blood vessels. In general, EPR-mediated passive targeting highly relies on the prolonged circulation time of nanocarriers. Particularly important two parameters, (1) nanocarrier size and (2) surface property are expected to play a key role on the pharmacokinetics and the biodistribution of the carrier material. Previously studies highlighted protein corona neutrality as an important design in the development of targeted nanomaterial delivery and demonstrated that a small difference in the surface heterogeneity could result in profoundly different interactions with cells and tissues. Therefore, the control and understanding of protein corona composition are critical for successful EPR-targeted nanomedicine. I will use mesoporous silica nanoparticles (MSN) nanoparticles as an example to illustrate the effect of size and the surface heterogeneity of MSN on their biological fate both in vitro and in vivo. I will also summarize our recent development of the circulating tumor cells (CTCs) isolation chips. CTCs are cancer cells that break away from a primary tumor or metastatic site, escape from immunosurveillance, and then circulate in the peripheral blood with the capability of forming distant metastases. The identification of CTCs in patient blood samples is technically challenging because of the extremely low concentration of CTCs among a large number of hematologic cells. To address this unmet need for rare cell isolation, we have developed substrates using the synergistic effect of nanomaterials and biological immobilization of CTC markers for enhancing CTC capture efficiency during a liquid biopsy procedure. In addition to the pursuit of high-cell-capture yield and specificity from human blood on chips, further vertical integration for the downstream characterization of CTCs is required for future CTC chips, such as liquid biopsy, for achieving a variety of clinical applications. In our approach, we have employed three-dimensional (3D) conducting polymer-based bioelectronic interfaces (BEIs) that can be integrated on electronic devices for rare circulating tumor cell (CTC) isolation, detection, and collection via an electrically triggered cell released from chips.

Aligned Nanofibrous Cell-Derived Extracellular Matrix for Anisotropic Vascular Graft Construction.

There is a large demand for tissue engineered vascular grafts for the application of vascular reconstruction surgery or in vitro drug screening tissue model. The extracellular matrix (ECM) composition along with the structural and mechanical anisotropy of native blood vessels is critical to their functional performance. The objective of this study is to develop a biomimetic vascular graft recapitulating the anisotropic features of native blood vessels by employing nanofibrous aligned fibroblast-derived ECM and human mesenchymal stem cells (hMSCs). The nanotopographic cues of aligned ECM direct the initial cell orientation. The subsequent maturation under circumferential stress generated by a rotating wall vessel (RWV) bioreactor further promotes anisotropic structural and mechanical properties in the graft. The circumferential tensile strength is significantly higher than longitudinal strength in bioreactor samples. Expression of smooth muscle cell specific genes, α-smooth muscle actin and calponin, in hMSCs is greatly enhanced in bioreactor samples without any biochemical stimulation. In addition, employment of premade ECM and RWV bioreactor significantly reduces the graft fabrication time to three weeks. Mimicking the ECM composition, cell phenotype, structural and mechanical anisotropy, the vascular graft presented in this study is promising for vascular reconstruction surgery or in vitro tissue model applications.

Visualization of tumor-related blood vessels in human breast by photoacoustic imaging system with a hemispherical detector array

Noninvasive measurement of the distribution and oxygenation state of hemoglobin (Hb) inside the tissue is strongly required to analyze the tumor-associated vasculatures. We developed a photoacoustic imaging (PAI) system with a hemispherical-shaped detector array (HDA). Here, we show that PAI system with HDA revealed finer vasculature, more detailed blood-vessel branching structures, and more detailed morphological vessel characteristics compared with MRI by the use of breast shape deformation of MRI to PAI and their fused image. Morphologically abnormal peritumoral blood vessel features, including centripetal photoacoustic signals and disruption or narrowing of vessel signals, were observed and intratumoral signals were detected by PAI in breast cancer tissues as a result of the clinical study of 22 malignant cases. Interestingly, it was also possible to analyze anticancer treatment-driven changes in vascular morphological features and function, such as improvement of intratumoral blood perfusion and relevant changes in intravascular hemoglobin saturation of oxygen. This clinical study indicated that PAI appears to be a promising tool for noninvasive analysis of human blood vessels and may contribute to improve cancer diagnosis.

Hybrid polymer microfluidic platform to mimic varying vascular compliance and topology.

Several cardiovascular pathologies and aging have been associated with alterations in the mechanical and structural properties of the vascular wall, leading to a reduction in arterial compliance and the development of constriction. In the past, rare efforts have been directed to understand the endothelial cell response to combined mechanical stimuli from fluid flow and substrate rigidity. Recent approaches using microfluidic platforms have limitations in precisely mimicking healthy and diseased vasculature conditions from altered topological and substrate compliance perspectives. To address this, we demonstrated an effective fabrication process to realize a hybrid polymer platform to test these mechanistic features of blood vessels. The salient features of the platform include circular microchannels of varying diameters, variation in substrate rigidity along the channel length, and the coexistence of microchannels with different cross sections on a single platform. The platform demonstrates the combined effects of flow-induced shear forces and substrate rigidity on the endothelial cell layer inside the circular microchannels. The experimental results indicate a pronounced cell response to flow induced shear stress via its interplay with the underlying substrate mechanics.

An Identification of Efficient Vessel Feature for Endoscopic Analysis

An indispensable chore in computer–aided Minimally Invasive Surgery (MIS) is the typical feature detection. In some of the distinctive conditions in MIS imaging such as texture homogeneous areas specular reflections uses general feature point detectors for drawing out the feature points which are less distinct and repeatable in MIS images. We examine that a new set of image feature can be taken out from the copious blood vessels which are obtainable from the tissue surfaces. Two types of blood vessel feature are put forward for endoscopic image analysis in this proposed paper: branching segments and branching points. Ridgeness Based Circle Test (RBCT) and Ridgeness Based Branching Segment Detection (RBSD) are the two new proposed methods used to obtain the branching points and branching segments from the blood vessels. To estimate the working effectiveness of the proposed method extensive in vivo experiments are carried out and the state-of-the-art method is used to evaluate them. In MIS images, the blood vessels from the tissue surfaces can yield enormous large number of points, which is proved from the numerical results. The points produced by the blood vessels are more robust and repeatable when compared with other types of feature points. This type of feature detection can be used as a new tool for the analysis of MIS images in endoscopy. Thus, the proposed method for detecting feature point is very efficient and robust in nature.

A Novel Approach for Detection of Microaneurysms in Diabetic Retinopathy Disease from Retinal Fundus Images

Diabetic Retinopathy (DR) is a leading cause of blindness in human beings aged between 20 to 74 years. It has a great influence on the patient and society because it normally influences humans in their most gainful years. Early detection in DR is very difficult which is not detected by human beings. Many algorithms and techniques were established to detect DR. These techniques faced the problems such as increasing sensitivity, specificity and accuracy. To overcome those problems we have to introduce an effective image processing algorithms for increasing performances and also easily identify the DR diseases. One of the most challenging tasks in screening is automatic detection of Microaneurysms (MAs). This paper presents a new approach to detect MAs. Our proposed work consists of preprocessing, blood vessel segmentation (FPCM), fovea localization, fovea elimination, feature extraction and classification (Neuro-Fuzzy). Neuro-Fuzzy is a combined version of neural networks and fuzzy logical models. Experiments are conducted using MATLAB simulation tool. Using MESSIDOR database for our experiments which provides efficient and effective results in sensitivity, specificity, correct classification and detection rate (accuracy) and precision.

Exudate and Blood Vessel Feature Extraction in Diabetic Retinopathy Patients using Morphology Operation

Diabetic Retinopathy is one of the retina complications caused by diabetic disease with observable symptoms such as emergence of exudate and new blood vessels. The tool used to screen it is a fundus camera. However, analyzing the fundus image should be done by doctor who is an expert and will require a lot of time. Therefore, automatic feature detection can assist doctor in processing the retinal image in analyzing diabetic retinopathy disease. The proposed method has been tested on the morphological operations of the fundus image from Cicendo Eye Hospital, Bandung. The calculation results on feature extraction exudate area has a range of 0 pixels for normal retinal image, 17-21213 pixel for retinal image NPDR, and 125-12299 retinal image pixel for PDR. The calculation results on the extraction area of blood vessels has a range of 13319-46681 pixel to the normal retina, the retinal image 7435-49938 pixel for NPDR, and 13.81-53.802 retinal image pixel for PDR.

Cтруктура миокарда молодых гипертензивных крыс после введения криоконсервированных ядросодержащих клеток кордовой крови человека

Nowadays cell therapy is considered as a promising new method to treat various diseases of cardiovascular system. Experimental model of stress-induced arterial hypertension (AH) was used to study the histological features of heart tissues and blood vessels: we have performed histochemical and polarization-optical assessment of collagen and elastic fibers of myocardium of young rats before and after introduction of human cryopreserved cord blood nucleated cells (cCBNCs). It has been found that myocardium structure of young rats to day 30 after the hypertension onset had pathological changes. We have found the changes in muscle fibers, spasm of blood vessels, paresis of the veins and capillaries, perivascular edema and cardiosclerosis. To day 3 after application of cCBNCs the number and area of cardiomyocyte nuclei increased. These compensatory changes were accompanied with a pronounced neoangiogenesis. One month later the administration of cCBNCs the density of fibroblasts in cardiac muscle of hypertensive rats increased (number of fibroblasts per area unit) in interstitial connective tissue and around the blood vessels; no areas with signs of focal ischemia and cardiosclerosis were noted. Perivascular and interstitial edemas were less pronounced. Probl Cryobiol Cryomed 2016; 26(3): 271–287

An Enhanced Segmentation Technique for Blood Vessel in Retinal Images

of the major symptoms of many blood related diseases like diabetes or cardiovascular disease is the change in blood vessel features. These diseases can be detected by analyzing features of retinal vessels and proper treatment can be provided to patient in early stages of disease. Cost associated in detecting these changes and inconsistency in the detection procedure led to the automation of this process. Among other tasks, retinal blood vessel segmentation is the foremost and very challenging task from which various features are analyzed to detect the disease. In this paper, an effective blood vessel segmentation method from coloured retinal fundus images is presented. Segmentation is done by extracting the green channel from RGB retinal image. Firstly the vessel structure is estimated using morphological operations and then noise is removed using Rician Denoise method. After removing the noise, segmentation of blood vessels is carried out using thresholding method. Segmented image needs to be post-processed before considering it for examining any disease. Proposed segmentation method was evaluated on two publicly available DRIVE and STARE datasets. Segmentation process achieves high level of accuracy than most of the previous techniques. Further, results have demonstrated that the proposed method is applicable for segmenting retinal vessels and taking measurements from it. Advantages of this method are its simplicity, fast segmentation process, high efficiency and scalability to deal with coloured retinal images of high resolution.

A Review of the Literature on Extrarenal Retroperitoneal Angiomyolipoma.

Background. Extrarenal retroperitoneal angiomyolipomas are rare. Aim. To review the literature. Results. Angiomyolipomas, previously classified as hamartomas, are now classified as benign tumours. Thirty cases of primary retroperitoneal angiomyolipomas have been reported. Diagnosis of the disease upon is based radiological and pathological findings of triphasic features of (a) fat and (b) blood vessels and myoid tissue. Immunohistochemistry tends to be positive for HMB45, MART1, HHF35, calponin, NKI-C3, and CD117. The lesion is common in women. Treatment options have included the following: (a) radical surgical excision of the lesion with renal sparing surgery or radical nephrectomy in cases where malignant tumours could not be excluded and (b) selective embolization of the lesion alone or prior to surgical excision. One case of retroperitoneal angiomyolipoma was reported in a patient 15 years after undergoing radical nephrectomy for angiomyolipoma of kidney and two cases of distant metastases of angiomyolipoma have been reported following radical resection of the tumour. Conclusions. With the report of two cases of metastases ensuing surgical resection of the primary lesions there is need for academic pathologists to debate and review angiomyolipomas to decide whether to reclassify angiomyolipomas as slow-growing malignant tumours or whether the reported cases of metastases were de novo tumours or metastatic lesions.

Regional Heterogeneity of Cerebral Microvessels and Brain Susceptibility to Oxidative Stress

The hippocampus is one of the earliest and most affected regions in Alzheimer’s disease (AD), followed by the cortex while the cerebellum is largely spared. Importantly, endothelial dysfunction is a common feature of cerebral blood vessels in AD. In this study, we sought to determine if regional heterogeneity of cerebral microvessels might help explain the susceptibility of the hippocampus and cortex as compared to the cerebellum. We isolated microvessels from wild type mice from the cerebellum, cortex, and hippocampus to characterize their vascular phenotype. Superoxide anion was significantly higher in microvessels isolated from the cortex and hippocampus as compared to the cerebellum. Importantly, protein levels of NADPH oxidase (NOX)-2 and NOX-4 were significantly higher in the cortical and hippocampal microvessels as compared to microvessels from the cerebellum. In addition, expression of manganese superoxide dismutase protein was significantly lower in microvessels from the cortex and hippocampus as compared to cerebellum while other antioxidant enzymes were unchanged. There was no difference in eNOS protein expression between the microvessels of the three brain regions; however, bioavailability of tetrahydrobiopterin (BH4), an essential cofactor for eNOS activity, was significantly reduced in microvessels from the hippocampus and cortex as compared to the cerebellum. Higher levels of superoxide and reduced tetrahydrobiopterin bioavailability may help explain the vulnerability of the hippocampus and cortical microvessels to oxidative stress and development of endothelial dysfunction.