WorldWideScience

Sample records for blood vessel removal

  1. Improvement of retinal blood vessel detection by spur removal and Gaussian matched filtering compensation

    Science.gov (United States)

    Xiao, Di; Vignarajan, Janardhan; An, Dong; Tay-Kearney, Mei-Ling; Kanagasingam, Yogi

    2016-03-01

    Retinal photography is a non-invasive and well-accepted clinical diagnosis of ocular diseases. Qualitative and quantitative assessment of retinal images is crucial in ocular diseases related clinical application. In this paper, we proposed approaches for improving the quality of blood vessel detection based on our initial blood vessel detection methods. A blood vessel spur pruning method has been developed for removing the blood vessel spurs both on vessel medial lines and binary vessel masks, which are caused by artifacts and side-effect of Gaussian matched vessel enhancement. A Gaussian matched filtering compensation method has been developed for removing incorrect vessel branches in the areas of low illumination. The proposed approaches were applied and tested on the color fundus images from one publicly available database and our diabetic retinopathy screening dataset. A preliminary result has demonstrated the robustness and good performance of the proposed approaches and their potential application for improving retinal blood vessel detection.

  2. Improvements in the Quantitative Assessment of Cerebral Blood Volume and Flow with the Removal of Vessel Voxels from MR Perfusion Images

    Directory of Open Access Journals (Sweden)

    Michael Mu Huo Teng

    2013-01-01

    Full Text Available Objective. To improve the quantitative assessment of cerebral blood volume (CBV and flow (CBF in the brain voxels from MR perfusion images. Materials and Methods. Normal brain parenchyma was automatically segmented with the time-to-peak criteria after cerebrospinal fluid removal and preliminary vessel voxel removal. Two scaling factors were calculated by comparing the relative CBV and CBF of the segmented normal brain parenchyma with the absolute values in the literature. Using the scaling factors, the relative values were converted to the absolute CBV and CBF. Voxels with either CBV > 8 mL/100 g or CBF > 100 mL/100 g/min were characterized as vessel voxels and were excluded from the quantitative measurements. Results. The segmented brain parenchyma with normal perfusion was consistent with the angiographic findings for each patient. We confirmed the necessity of dual thresholds including CBF and CBV for proper removal of vessel voxels. The scaling factors were 0.208 ± 0.041 for CBV, and 0.168 ± 0.037, 0.172 ± 0.037 for CBF calculated using standard and circulant singular value decomposition techniques, respectively. Conclusion. The automatic scaling and vessel removal techniques provide an alternative method for obtaining improved quantitative assessment of CBV and CBF in patients with thromboembolic cerebral arterial disease.

  3. Polymer-based blood vessel models with micro-temperature sensors in EVE

    Science.gov (United States)

    Mizoshiri, Mizue; Ito, Yasuaki; Hayakawa, Takeshi; Maruyama, Hisataka; Sakurai, Junpei; Ikeda, Seiichi; Arai, Fumihito; Hata, Seiichi

    2017-04-01

    Cu-based micro-temperature sensors were directly fabricated on poly(dimethylsiloxane) (PDMS) blood vessel models in EVE using a combined process of spray coating and femtosecond laser reduction of CuO nanoparticles. CuO nanoparticle solution coated on a PDMS blood vessel model are thermally reduced and sintered by focused femtosecond laser pulses in atmosphere to write the sensors. After removing the non-irradiated CuO nanoparticles, Cu-based microtemperature sensors are formed. The sensors are thermistor-type ones whose temperature dependences of the resistance are used for measuring temperature inside the blood vessel model. This fabrication technique is useful for direct-writing of Cu-based microsensors and actuators on arbitrary nonplanar substrates.

  4. Electrical discharge machining for vessel sample removal

    International Nuclear Information System (INIS)

    Litka, T.J.

    1993-01-01

    Due to aging-related problems or essential metallurgy information (plant-life extension or decommissioning) of nuclear plants, sample removal from vessels may be required as part of an examination. Vessel or cladding samples with cracks may be removed to determine the cause of cracking. Vessel weld samples may be removed to determine the weld metallurgy. In all cases, an engineering analysis must be done prior to sample removal to determine the vessel's integrity upon sample removal. Electrical discharge machining (EDM) is being used for in-vessel nuclear power plant vessel sampling. Machining operations in reactor coolant system (RCS) components must be accomplished while collecting machining chips that could cause damage if they become part of the flow stream. The debris from EDM is a fine talclike particulate (no chips), which can be collected by flushing and filtration

  5. Absorbed dose calculations to blood and blood vessels for internally deposited radionuclides

    International Nuclear Information System (INIS)

    Akabani, G.; Poston, J.W. Sr.

    1992-01-01

    At present, absorbed dose calculations for radionuclides in the human circulatory system use relatively simple models and are restricted in their applications. To determine absorbed doses to the blood and to the surface of the blood vessel wall, Monte Carlo calculations were performed using the code Electron Gamma Shower (EGS4). Absorbed doses were calculated for the blood and the blood vessel wall (lumen) for different blood vessel sizes. The radionuclides chosen for this study were those commonly used in nuclear medicine. No diffusion of the radionuclide into the blood vessel was or cross fire between blood vessels was assumed. Results are useful in assessing the doses to blood and blood vessel walls for different nuclear medicine procedures

  6. New algorithm for detecting smaller retinal blood vessels in fundus images

    Science.gov (United States)

    LeAnder, Robert; Bidari, Praveen I.; Mohammed, Tauseef A.; Das, Moumita; Umbaugh, Scott E.

    2010-03-01

    About 4.1 million Americans suffer from diabetic retinopathy. To help automatically diagnose various stages of the disease, a new blood-vessel-segmentation algorithm based on spatial high-pass filtering was developed to automatically segment blood vessels, including the smaller ones, with low noise. Methods: Image database: Forty, 584 x 565-pixel images were collected from the DRIVE image database. Preprocessing: Green-band extraction was used to obtain better contrast, which facilitated better visualization of retinal blood vessels. A spatial highpass filter of mask-size 11 was applied. A histogram stretch was performed to enhance contrast. A median filter was applied to mitigate noise. At this point, the gray-scale image was converted to a binary image using a binary thresholding operation. Then, a NOT operation was performed by gray-level value inversion between 0 and 255. Postprocessing: The resulting image was AND-ed with its corresponding ring mask to remove the outer-ring (lens-edge) artifact. At this point, the above algorithm steps had extracted most of the major and minor vessels, with some intersections and bifurcations missing. Vessel segments were reintegrated using the Hough transform. Results: After applying the Hough transform, both the average peak SNR and the RMS error improved by 10%. Pratt's Figure of Merit (PFM) was decreased by 6%. Those averages were better than [1] by 10-30%. Conclusions: The new algorithm successfully preserved the details of smaller blood vessels and should prove successful as a segmentation step for automatically identifying diseases that affect retinal blood vessels.

  7. Absorbed dose calculations to blood and blood vessels for internally deposited radionuclides

    International Nuclear Information System (INIS)

    Akabani, G.; Poston, J.W.

    1991-05-01

    At present, absorbed dose calculations for radionuclides in the human circulatory system used relatively simple models and are restricted in their applications. To determine absorbed doses to the blood and to the surface of the blood vessel wall, EGS4 Monte Carlo calculations were performed. Absorbed doses were calculated for the blood and the blood vessel wall (lumen) for different blood vessels sizes. The radionuclides chosen for this study were those commonly used in nuclear medicine. No diffusion of the radionuclide into the blood vessel was assumed nor cross fire between vessel was assumed. Results are useful in assessing the dose in blood and blood vessel walls for different nuclear medicine procedures. 6 refs., 6 figs., 5 tabs

  8. A thresholding based technique to extract retinal blood vessels from fundus images

    Directory of Open Access Journals (Sweden)

    Jyotiprava Dash

    2017-12-01

    Full Text Available Retinal imaging has become the significant tool among all the medical imaging technology, due to its capability to extract many data which is linked to various eye diseases. So, the accurate extraction of blood vessel is necessary that helps the eye care specialists and ophthalmologist to identify the diseases at the early stages. In this paper, we have proposed a computerized technique for extraction of blood vessels from fundus images. The process is conducted in three phases: (i pre-processing where the image is enhanced using contrast limited adaptive histogram equalization and median filter, (ii segmentation using mean-C thresholding to extract retinal blood vessels, (iii post-processing where morphological cleaning operation is used to remove isolated pixels. The performance of the proposed method is tested on and experimental results show that our method achieve an accuracies of 0.955 and 0.954 on Digital retinal images for vessel extraction (DRIVE and Child heart and health study in England (CHASE_DB1 databases respectively.

  9. TMI-2 reactor vessel head removal

    International Nuclear Information System (INIS)

    Bengel, P.R.; Smith, M.D.; Estabrook, G.A.

    1984-12-01

    This report describes the safe removal and storage of the Three Mile Island Unit 2 reactor vessel head. The head was removed in July 1984 to permit the removal of the plenum and the reactor core, which were damaged during the 1979 accident. From July 1982, plans and preparations were made using a standard head removal procedure modified by the necessary precautions and changes to account for conditions caused by the accident. After data acquisition, equipment and structure modifications, and training the head was safely removed and stored and the internals indexing fixture and a work platform were installed on top of the vessel. Dose rates during and after the operation were lower than expected; lessons were learned from the operation which will be applied to the continuing fuel removal operations activities

  10. TMI-2 reactor vessel head removal

    International Nuclear Information System (INIS)

    Bengel, P.R.; Smith, M.D.; Estabrook, G.A.

    1985-09-01

    This report describes the safe removal and storage of the Three Mile Island Unit 2 (TMI-2) reactor vessel head. The head was removed in July 1984 to permit the removal of the plenum and the reactor core, which were damaged during the 1979 accident. From July 1982, plans and preparations were made using a standard head removal procedure modified by the necessary precautions and changes to account for conditions caused by the accident. After data acquisition, equipment and structure modifications, and training, the head was safely removed and stored; and the internals indexing fixture and a work platform were installed on top of the vessel. Dose rates during and after the operation were lower than expected; lessons were learned from the operation which will be applied to the continuing fuel removal operations activities

  11. Estimation of center line and diameter of brain blood vessel using three-dimensional blood vessel matching method with head three-dimensional CTA image

    International Nuclear Information System (INIS)

    Maekawa, Masashi; Shinohara, Toshihiro; Nakayama, Masato; Nakasako, Noboru

    2010-01-01

    To support and automate the brain blood vessel disease diagnosis, a novel method to obtain the center line and the diameter of a blood vessel is proposed with a three-dimensional head computed tomographic angiography (CTA) image. Although the line thinning processing with distance transform or gray information is generally used to obtain the blood vessel center line, this method is not essentially one to obtain the center line and tends to yield extra lines depending on CTA images. In this study, the center line of the blood vessel is obtained by tracing the vessel. The blood vessel is traced by sequentially estimating the center point and direction of the blood vessel. The center point and direction of the blood vessel are estimated by taking the correlation between the blood vessel and a solid model of the blood vessel that is designed by considering noise influence. In addition, the vessel diameter is also estimated by correlating the blood vessel and the blood vessel model of which the diameter is variable. The validity of the proposed method is confirmed by experimentally applied the proposed method to an actual three-dimensional head CTA image. (author)

  12. Fe3O4@ZnO core-shell nanocomposites for efficient and repetitive removal of low density lipoprotein in plasma and on blood vessel

    International Nuclear Information System (INIS)

    Huang, Xiao; Lu, Juan; Yue, Danyang; Fan, Yijuan; Yi, Caixia; Wang, Xiaoying; Zhang, Mengxue; Pan, Jun

    2015-01-01

    Low density lipoprotein (LDL)-apheresis therapy, which directly removes LDL from plasma by LDL-adsorbents in vitro is found to be clinically effective and safe to lower the LDL content in blood to prevent cardiovascular disease. Thus, developing excellent LDL adsorbents are becoming more and more attractive. Herein, functional Fe 3 O 4 @ZnO core–shell nanocomposites have been synthesized by a facile and eco-friendly two-step method. Not only do they possess high LDL adsorption (in PBS/plasma as well as on blood vessels) and favorable magnetic targeting ability but they can also be reused conveniently, which offer the Fe 3 O 4 @ZnO core–shell nanocomposites significant potential in the removal of LDL in vitro and in vivo. (paper)

  13. NMR blood vessel imaging method and apparatus

    International Nuclear Information System (INIS)

    Riederer, S.J.

    1988-01-01

    A high speed method of forming computed images of blood vessels based on measurements of characteristics of a body is described comprising the steps of: subjecting a predetermined body area containing blood vessels of interest to, successively, applications of a short repetition time (TR) NMR pulse sequence during the period of high blood velocity and then to corresponding applications during the period of low blood velocity for successive heart beat cycles; weighting the collected imaging data from each application of the NMR pulse sequence according to whether the data was acquired during the period of high blood velocity or a period of low blood velocity of the corresponding heart beat cycle; accumulating weighted imaging data from a plurality of NMR pulse sequences corresponding to high blood velocity periods and from a plurality of NMR pulse sequences corresponding to low blood velocity periods; subtracting the weighted imaging data corresponding to each specific phase encoding acquired during the high blood velocity periods from the weighted imaging data for the same phase encoding corresponding to low blood velocity periods in order to compute blood vessel imaging data; and forming an image of the blood vessels of interest from the blood vessel imaging data

  14. Tumor Blood Vessel Dynamics

    Science.gov (United States)

    Munn, Lance

    2009-11-01

    ``Normalization'' of tumor blood vessels has shown promise to improve the efficacy of chemotherapeutics. In theory, anti-angiogenic drugs targeting endothelial VEGF signaling can improve vessel network structure and function, enhancing the transport of subsequent cytotoxic drugs to cancer cells. In practice, the effects are unpredictable, with varying levels of success. The predominant effects of anti-VEGF therapies are decreased vessel leakiness (hydraulic conductivity), decreased vessel diameters and pruning of the immature vessel network. It is thought that each of these can influence perfusion of the vessel network, inducing flow in regions that were previously sluggish or stagnant. Unfortunately, when anti-VEGF therapies affect vessel structure and function, the changes are dynamic and overlapping in time, and it has been difficult to identify a consistent and predictable normalization ``window'' during which perfusion and subsequent drug delivery is optimal. This is largely due to the non-linearity in the system, and the inability to distinguish the effects of decreased vessel leakiness from those due to network structural changes in clinical trials or animal studies. We have developed a mathematical model to calculate blood flow in complex tumor networks imaged by two-photon microscopy. The model incorporates the necessary and sufficient components for addressing the problem of normalization of tumor vasculature: i) lattice-Boltzmann calculations of the full flow field within the vasculature and within the tissue, ii) diffusion and convection of soluble species such as oxygen or drugs within vessels and the tissue domain, iii) distinct and spatially-resolved vessel hydraulic conductivities and permeabilities for each species, iv) erythrocyte particles advecting in the flow and delivering oxygen with real oxygen release kinetics, v) shear stress-mediated vascular remodeling. This model, guided by multi-parameter intravital imaging of tumor vessel structure

  15. Blood Vessel-Derived Acellular Matrix for Vascular Graft Application

    Directory of Open Access Journals (Sweden)

    Luigi Dall’Olmo

    2014-01-01

    Full Text Available To overcome the issues connected to the use of autologous vascular grafts and artificial materials for reconstruction of small diameter (<6 mm blood vessels, this study aimed to develop acellular matrix- (AM- based vascular grafts. Rat iliac arteries were decellularized by a detergent-enzymatic treatment, whereas endothelial cells (ECs were obtained through enzymatic digestion of rat skin followed by immunomagnetic separation of CD31-positive cells. Sixteen female Lewis rats (8 weeks old received only AM or previously in vitro reendothelialized AM as abdominal aorta interposition grafts (about 1 cm. The detergent-enzymatic treatment completely removed the cellular part of vessels and both MHC class I and class II antigens. One month after surgery, the luminal surface of implanted AMs was partially covered by ECs and several platelets adhered in the areas lacking cell coverage. Intimal hyperplasia, already detected after 1 month, increased at 3 months. On the contrary, all grafts composed by AM and ECs were completely covered at 1 month and their structure was similar to that of native vessels at 3 months. Taken together, our findings show that prostheses composed of AM preseeded with ECs could be a promising approach for the replacement of blood vessels.

  16. Ionizing radiations and blood vessels

    International Nuclear Information System (INIS)

    Vorob'ev, E.I.; Stepanov, R.P.

    1985-01-01

    Data on phenomeology of radiation changes of blood vessels are systemized and the authors' experience is generalyzed. A critical analysis of modern conceptions on processes resulting in vessel structure damage after irradiation, is given. Special attention is paid to reparation and compensation of radiation injury of vessels

  17. Bone marrow blood vessels: normal and neoplastic niche

    Directory of Open Access Journals (Sweden)

    Saeid Shahrabi

    2016-11-01

    Full Text Available Blood vessels are among the most important factors in the transport of materials such as nutrients and oxygen. This study will review the role of blood vessels in normal bone marrow hematopoiesis as well as pathological conditions like leukemia and metastasis. Relevant literature was identified by a Pubmed search (1992-2016 of English-language papers using the terms bone marrow, leukemia, metastasis, and vessel. Given that blood vessels are conduits for the transfer of nutrients, they create a favorable situation for cancer cells and cause their growth and development. On the other hand, blood vessels protect leukemia cells against chemotherapy drugs. Finally, it may be concluded that the vessels are an important factor in the development of malignant diseases.

  18. Ionizing radiations and blood vessels

    International Nuclear Information System (INIS)

    Vorob'ev, E.I.; Stepanov, R.P.

    1985-01-01

    Data on phenomenology of radiation-induced changes in blood vessels are systematized and authors' experience is generalized. Modern concepts about processes leading to vessel structure injury after irradiation is critically analyzed. Special attention is paid to reparation and compensation of X-ray vessel injury, consideration of which is not yet sufficiently elucidated in literature

  19. Trends in Tissue Engineering for Blood Vessels

    Directory of Open Access Journals (Sweden)

    Judee Grace Nemeno-Guanzon

    2012-01-01

    Full Text Available Over the years, cardiovascular diseases continue to increase and affect not only human health but also the economic stability worldwide. The advancement in tissue engineering is contributing a lot in dealing with this immediate need of alleviating human health. Blood vessel diseases are considered as major cardiovascular health problems. Although blood vessel transplantation is the most convenient treatment, it has been delimited due to scarcity of donors and the patient’s conditions. However, tissue-engineered blood vessels are promising alternatives as mode of treatment for blood vessel defects. The purpose of this paper is to show the importance of the advancement on biofabrication technology for treatment of soft tissue defects particularly for vascular tissues. This will also provide an overview and update on the current status of tissue reconstruction especially from autologous stem cells, scaffolds, and scaffold-free cellular transplantable constructs. The discussion of this paper will be focused on the historical view of cardiovascular tissue engineering and stem cell biology. The representative studies featured in this paper are limited within the last decade in order to trace the trend and evolution of techniques for blood vessel tissue engineering.

  20. TMI-2 reactor-vessel head removal and damaged-core-removal planning

    International Nuclear Information System (INIS)

    Logan, J.A.; Hultman, C.W.; Lewis, T.J.

    1982-01-01

    A major milestone in the cleanup and recovery effort at TMI-2 will be the removal of the reactor vessel closure head, planum, and damaged core fuel material. The data collected during these operations will provide the nuclear power industry with valuable information on the effects of high-temperature-dissociated coolant on fuel cladding, fuel materials, fuel support structural materials, neutron absorber material, and other materials used in reactor structural support components and drive mechanisms. In addition, examination of these materials will also be used to determine accident time-temperature histories in various regions of the core. Procedures for removing the reactor vessel head and reactor core are presented

  1. Distinct bone marrow blood vessels differentially regulate haematopoiesis.

    Science.gov (United States)

    Itkin, Tomer; Gur-Cohen, Shiri; Spencer, Joel A; Schajnovitz, Amir; Ramasamy, Saravana K; Kusumbe, Anjali P; Ledergor, Guy; Jung, Yookyung; Milo, Idan; Poulos, Michael G; Kalinkovich, Alexander; Ludin, Aya; Kollet, Orit; Shakhar, Guy; Butler, Jason M; Rafii, Shahin; Adams, Ralf H; Scadden, David T; Lin, Charles P; Lapidot, Tsvee

    2016-04-21

    Bone marrow endothelial cells (BMECs) form a network of blood vessels that regulate both leukocyte trafficking and haematopoietic stem and progenitor cell (HSPC) maintenance. However, it is not clear how BMECs balance these dual roles, and whether these events occur at the same vascular site. We found that mammalian bone marrow stem cell maintenance and leukocyte trafficking are regulated by distinct blood vessel types with different permeability properties. Less permeable arterial blood vessels maintain haematopoietic stem cells in a low reactive oxygen species (ROS) state, whereas the more permeable sinusoids promote HSPC activation and are the exclusive site for immature and mature leukocyte trafficking to and from the bone marrow. A functional consequence of high permeability of blood vessels is that exposure to blood plasma increases bone marrow HSPC ROS levels, augmenting their migration and differentiation, while compromising their long-term repopulation and survival. These findings may have relevance for clinical haematopoietic stem cell transplantation and mobilization protocols.

  2. Automatic segmentation of blood vessels from retinal fundus images ...

    Indian Academy of Sciences (India)

    The retinal blood vessels were segmented through color space conversion and color channel .... Retinal blood vessel segmentation was also attempted through multi-scale operators. A few works in this ... fundus camera at 35 degrees field of view. The image ... vessel segmentation is available from two human observers.

  3. Recovery of testicular blood flow following ligation of testicular vessels

    International Nuclear Information System (INIS)

    Pascual, J.A.; Villanueva-Meyer, J.; Salido, E.; Ehrlich, R.M.; Mena, I.; Rajfer, J.

    1989-01-01

    To determine whether initial ligation of the testicular vessels of the high undescended testis followed by a delayed secondary orchiopexy is a viable alternative to the classical Fowler-Stephens procedure, a series of preliminary experiments were conducted in the rat in which testicular blood flow was measured by the 133-xenon washout technique before, and 1 hour and 30 days after ligation of the vessels. In addition, testicular histology, and testis and sex-accessory tissue weights were measured in 6 control, 6 sham operated and 6 testicular vessel ligated rats 54 days after vessel ligation. The data demonstrate that ligation and division of the testicular blood vessels produce an 80 per cent decrease in testicular blood flow 1 hour after ligation of the vessels. However, 30 days later testis blood flow returns to the control and pre-treatment value. There were no significant changes in testis or sex-accessory tissue weights 54 days after vessel ligation. Histologically, 4 of the surgically operated testes demonstrated necrosis of less than 25 per cent of the seminiferous tubules while 1 testis demonstrated more than 75 per cent necrosis. The rest of the tubules in all 6 testes demonstrated normal spermatogenesis. From this study we conclude that initial testicular vessel ligation produces an immediate decrease in testicular blood flow but with time the collateral vessels are able to compensate and return the testis blood flow to its normal pre-treatment value. These preliminary observations lend support for the concept that initial ligation of the testicular vessels followed by a delayed secondary orchiopexy in patients with a high undescended testis may be a possible alternative to the classical Fowler-Stephens approach

  4. Application of morphological bit planes in retinal blood vessel extraction.

    Science.gov (United States)

    Fraz, M M; Basit, A; Barman, S A

    2013-04-01

    The appearance of the retinal blood vessels is an important diagnostic indicator of various clinical disorders of the eye and the body. Retinal blood vessels have been shown to provide evidence in terms of change in diameter, branching angles, or tortuosity, as a result of ophthalmic disease. This paper reports the development for an automated method for segmentation of blood vessels in retinal images. A unique combination of methods for retinal blood vessel skeleton detection and multidirectional morphological bit plane slicing is presented to extract the blood vessels from the color retinal images. The skeleton of main vessels is extracted by the application of directional differential operators and then evaluation of combination of derivative signs and average derivative values. Mathematical morphology has been materialized as a proficient technique for quantifying the retinal vasculature in ocular fundus images. A multidirectional top-hat operator with rotating structuring elements is used to emphasize the vessels in a particular direction, and information is extracted using bit plane slicing. An iterative region growing method is applied to integrate the main skeleton and the images resulting from bit plane slicing of vessel direction-dependent morphological filters. The approach is tested on two publicly available databases DRIVE and STARE. Average accuracy achieved by the proposed method is 0.9423 for both the databases with significant values of sensitivity and specificity also; the algorithm outperforms the second human observer in terms of precision of segmented vessel tree.

  5. Fluid and mass transport in a single lymphatic blood vessel

    International Nuclear Information System (INIS)

    Bestman, A.R.

    1987-08-01

    The problem considers the single blood vessel model in pulmonary circulation in the presence of gravitation and mass transfer. The tissue surrounding the blood vessel is modelled as a permeable medium distinct from the blood vessel which is a normal free space. On the assumption that the mass concentration varies slowly at the interface between the blood vessel and the tissue, the problem is tackled by asymptotic approximation. A crucial point of the analysis is the dependence of the flow variables on the permeability K of the tissue in a completely arbitrary manner. A primary conjecture of the study is the intimacy of the pathological pulmonary edema and the parameter K. (author). 4 refs

  6. Margination of Stiffened Red Blood Cells Regulated By Vessel Geometry.

    Science.gov (United States)

    Chen, Yuanyuan; Li, Donghai; Li, Yongjian; Wan, Jiandi; Li, Jiang; Chen, Haosheng

    2017-11-10

    Margination of stiffened red blood cells has been implicated in many vascular diseases. Here, we report the margination of stiffened RBCs in vivo, and reveal the crucial role of the vessel geometry in the margination by calculations when the blood is seen as viscoelastic fluid. The vessel-geometry-regulated margination is then confirmed by in vitro experiments in microfluidic devices, and it establishes new insights to cell sorting technology and artificial blood vessel fabrication.

  7. A Morphological Hessian Based Approach for Retinal Blood Vessels Segmentation and Denoising Using Region Based Otsu Thresholding.

    Directory of Open Access Journals (Sweden)

    Khan BahadarKhan

    Full Text Available Diabetic Retinopathy (DR harm retinal blood vessels in the eye causing visual deficiency. The appearance and structure of blood vessels in retinal images play an essential part in the diagnoses of an eye sicknesses. We proposed a less computational unsupervised automated technique with promising results for detection of retinal vasculature by using morphological hessian based approach and region based Otsu thresholding. Contrast Limited Adaptive Histogram Equalization (CLAHE and morphological filters have been used for enhancement and to remove low frequency noise or geometrical objects, respectively. The hessian matrix and eigenvalues approach used has been in a modified form at two different scales to extract wide and thin vessel enhanced images separately. Otsu thresholding has been further applied in a novel way to classify vessel and non-vessel pixels from both enhanced images. Finally, postprocessing steps has been used to eliminate the unwanted region/segment, non-vessel pixels, disease abnormalities and noise, to obtain a final segmented image. The proposed technique has been analyzed on the openly accessible DRIVE (Digital Retinal Images for Vessel Extraction and STARE (STructured Analysis of the REtina databases along with the ground truth data that has been precisely marked by the experts.

  8. Immersive volume rendering of blood vessels

    Science.gov (United States)

    Long, Gregory; Kim, Han Suk; Marsden, Alison; Bazilevs, Yuri; Schulze, Jürgen P.

    2012-03-01

    In this paper, we present a novel method of visualizing flow in blood vessels. Our approach reads unstructured tetrahedral data, resamples it, and uses slice based 3D texture volume rendering. Due to the sparse structure of blood vessels, we utilize an octree to efficiently store the resampled data by discarding empty regions of the volume. We use animation to convey time series data, wireframe surface to give structure, and utilize the StarCAVE, a 3D virtual reality environment, to add a fully immersive element to the visualization. Our tool has great value in interdisciplinary work, helping scientists collaborate with clinicians, by improving the understanding of blood flow simulations. Full immersion in the flow field allows for a more intuitive understanding of the flow phenomena, and can be a great help to medical experts for treatment planning.

  9. Interstitial Cells of Blood Vessels

    Directory of Open Access Journals (Sweden)

    Vladimír Pucovský

    2010-01-01

    Full Text Available Blood vessels are made up of several distinct cell types. Although it was originally thought that the tunica media of blood vessels was composed of a homogeneous population of fully differentiated smooth muscle cells, more recent data suggest the existence of multiple smooth muscle cell subpopulations in the vascular wall. One of the cell types contributing to this heterogeneity is the novel, irregularly shaped, noncontractile cell with thin processes, termed interstitial cell, found in the tunica media of both veins and arteries. While the principal role of interstitial cells in veins seems to be pacemaking, the role of arterial interstitial cells is less clear. This review summarises the knowledge of the functional and structural properties of vascular interstitial cells accumulated so far, offers hypotheses on their physiological role, and proposes directions for future research.

  10. Depiction of blood vessels by x-ray phase contrast

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Atsushi [School of Engineering, University of Tokyo, Tokyo (Japan); Takeda, Tohoru; Itai, Yuji [Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki (Japan)

    2001-04-01

    Blood vessels in livers of a mouse and a rat were depicted by phase-contrast x-ray imaging with an x-ray interferometer without using contrast agents. X-ray interference patterns were converted to image mapping x-ray phase shift caused by the livers using the technique of phase-shifting x-ray interferometry. The arteries and veins to and from the livers were tied before excision in order to prevent blood from flowing out of the liver. The x-ray phase shift caused by blood was substantially different from that caused by other soft sues, and consequently trees of blood vessels were revealed in the images. Vessels of diameter smaller than 0.1 mm were detected. This result suggests new possibilities for investigating vascular systems. (author)

  11. Blood Vessel Extraction in Color Retinal Fundus Images with Enhancement Filtering and Unsupervised Classification

    Directory of Open Access Journals (Sweden)

    Zafer Yavuz

    2017-01-01

    Full Text Available Retinal blood vessels have a significant role in the diagnosis and treatment of various retinal diseases such as diabetic retinopathy, glaucoma, arteriosclerosis, and hypertension. For this reason, retinal vasculature extraction is important in order to help specialists for the diagnosis and treatment of systematic diseases. In this paper, a novel approach is developed to extract retinal blood vessel network. Our method comprises four stages: (1 preprocessing stage in order to prepare dataset for segmentation; (2 an enhancement procedure including Gabor, Frangi, and Gauss filters obtained separately before a top-hat transform; (3 a hard and soft clustering stage which includes K-means and Fuzzy C-means (FCM in order to get binary vessel map; and (4 a postprocessing step which removes falsely segmented isolated regions. The method is tested on color retinal images obtained from STARE and DRIVE databases which are available online. As a result, Gabor filter followed by K-means clustering method achieves 95.94% and 95.71% of accuracy for STARE and DRIVE databases, respectively, which are acceptable for diagnosis systems.

  12. “Data characterizing microfabricated human blood vessels created via hydrodynamic focusing”

    Directory of Open Access Journals (Sweden)

    Kyle A. DiVito

    2017-10-01

    Full Text Available This data article provides further detailed information related to our research article titled “Microfabricated Blood Vessels Undergo Neovascularization” (DiVito et al., 2017 [1], in which we report fabrication of human blood vessels using hydrodynamic focusing (HDF. Hydrodynamic focusing with advection inducing chevrons were used in concert to encase one fluid stream within another, shaping the inner core fluid into ‘bullseye-like” cross-sections that were preserved through click photochemistry producing streams of cellularized hollow 3-dimensional assemblies, such as human blood vessels (Daniele et al., 2015a, 2015b, 2014, 2016; Roberts et al., 2016 [2–6]. Applications for fabricated blood vessels span general tissue engineering to organ-on-chip technologies, with specific utility in in vitro drug delivery and pharmacodynamics studies. Here, we report data regarding the construction of blood vessels including cellular composition and cell positioning within the engineered vascular construct as well as functional aspects of the tissues.

  13. Acrolein generation stimulates hypercontraction in isolated human blood vessels

    International Nuclear Information System (INIS)

    Conklin, D.J.; Bhatnagar, A.; Cowley, H.R.; Johnson, G.H.; Wiechmann, R.J.; Sayre, L.M.; Trent, M.B.; Boor, P.J.

    2006-01-01

    Increased risk of vasospasm, a spontaneous hyperconstriction, is associated with atherosclerosis, cigarette smoking, and hypertension-all conditions involving oxidative stress, lipid peroxidation, and inflammation. To test the role of the lipid peroxidation- and inflammation-derived aldehyde, acrolein, in human vasospasm, we developed an ex vivo model using human coronary artery bypass graft (CABG) blood vessels and a demonstrated acrolein precursor, allylamine. Allylamine induces hypercontraction in isolated rat coronary artery in a semicarbazide-sensitive amine oxidase activity (SSAO) dependent manner. Isolated human CABG blood vessels (internal mammary artery, radial artery, saphenous vein) were used to determine: (1) vessel responses and sensitivity to acrolein, allylamine, and H 2 O 2 exposure (1 μM-1 mM), (2) SSAO dependence of allylamine-induced effects using SSAO inhibitors (semicarbazide, 1 mM; MDL 72274-E, active isomer; MDL 72274-Z, inactive isomer; 100 μM), (3) the vasoactive effects of two other SSAO amine substrates, benzylamine and methylamine, and (4) the contribution of extracellular Ca 2+ to hypercontraction. Acrolein or allylamine but not H 2 O 2 , benzylamine, or methylamine stimulated spontaneous and pharmacologically intractable hypercontraction in CABG blood vessels that was similar to clinical vasospasm. Allylamine-induced hypercontraction and blood vessel SSAO activity were abolished by pretreatment with semicarbazide or MDL 72274-E but not by MDL 72274-Z. Allylamine-induced hypercontraction also was significantly attenuated in Ca 2+ -free buffer. In isolated aorta of spontaneously hypertensive rat, allylamine-induced an SSAO-dependent contraction and enhanced norepinephrine sensitivity but not in Sprague-Dawley rat aorta. We conclude that acrolein generation in the blood vessel wall increases human susceptibility to vasospasm, an event that is enhanced in hypertension

  14. Captopril improves tumor nanomedicine delivery by increasing tumor blood perfusion and enlarging endothelial gaps in tumor blood vessels.

    Science.gov (United States)

    Zhang, Bo; Jiang, Ting; Tuo, Yanyan; Jin, Kai; Luo, Zimiao; Shi, Wei; Mei, Heng; Hu, Yu; Pang, Zhiqing; Jiang, Xinguo

    2017-12-01

    Poor tumor perfusion and unfavorable vessel permeability compromise nanomedicine drug delivery to tumors. Captopril dilates blood vessels, reducing blood pressure clinically and bradykinin, as the downstream signaling moiety of captopril, is capable of dilating blood vessels and effectively increasing vessel permeability. The hypothesis behind this study was that captopril can dilate tumor blood vessels, improving tumor perfusion and simultaneously enlarge the endothelial gaps of tumor vessels, therefore enhancing nanomedicine drug delivery for tumor therapy. Using the U87 tumor xenograft with abundant blood vessels as the tumor model, tumor perfusion experiments were carried out using laser Doppler imaging and lectin-labeling experiments. A single treatment of captopril at a dose of 100 mg/kg significantly increased the percentage of functional vessels in tumor tissues and improved tumor blood perfusion. Scanning electron microscopy of tumor vessels also indicated that the endothelial gaps of tumor vessels were enlarged after captopril treatment. Immunofluorescence-staining of tumor slices demonstrated that captopril significantly increased bradykinin expression, possibly explaining tumor perfusion improvements and endothelial gap enlargement. Additionally, imaging in vivo, imaging ex vivo and nanoparticle distribution in tumor slices indicated that after a single treatment with captopril, the accumulation of 115-nm nanoparticles in tumors had increased 2.81-fold with a more homogeneous distribution pattern in comparison to non-captopril treated controls. Finally, pharmacodynamics experiments demonstrated that captopril combined with paclitaxel-loaded nanoparticles resulted in the greatest tumor shrinkage and the most extensive necrosis in tumor tissues among all treatment groups. Taken together, the data from the present study suggest a novel strategy for improving tumor perfusion and enlarging blood vessel permeability simultaneously in order to improve

  15. Blood Vessels in Allotransplantation.

    Science.gov (United States)

    Abrahimi, P; Liu, R; Pober, J S

    2015-07-01

    Human vascularized allografts are perfused through blood vessels composed of cells (endothelium, pericytes, and smooth muscle cells) that remain largely of graft origin and are thus subject to host alloimmune responses. Graft vessels must be healthy to maintain homeostatic functions including control of perfusion, maintenance of permselectivity, prevention of thrombosis, and participation in immune surveillance. Vascular cell injury can cause dysfunction that interferes with these processes. Graft vascular cells can be activated by mediators of innate and adaptive immunity to participate in graft inflammation contributing to both ischemia/reperfusion injury and allograft rejection. Different forms of rejection may affect graft vessels in different ways, ranging from thrombosis and neutrophilic inflammation in hyperacute rejection, to endothelialitis/intimal arteritis and fibrinoid necrosis in acute cell-mediated or antibody-mediated rejection, respectively, and to diffuse luminal stenosis in chronic rejection. While some current therapies targeting the host immune system do affect graft vascular cells, direct targeting of the graft vasculature may create new opportunities for preventing allograft injury and loss. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

  16. Predictive simulation of bidirectional Glenn shunt using a hybrid blood vessel model.

    Science.gov (United States)

    Li, Hao; Leow, Wee Kheng; Chiu, Ing-Sh

    2009-01-01

    This paper proposes a method for performing predictive simulation of cardiac surgery. It applies a hybrid approach to model the deformation of blood vessels. The hybrid blood vessel model consists of a reference Cosserat rod and a surface mesh. The reference Cosserat rod models the blood vessel's global bending, stretching, twisting and shearing in a physically correct manner, and the surface mesh models the surface details of the blood vessel. In this way, the deformation of blood vessels can be computed efficiently and accurately. Our predictive simulation system can produce complex surgical results given a small amount of user inputs. It allows the surgeon to easily explore various surgical options and evaluate them. Tests of the system using bidirectional Glenn shunt (BDG) as an application example show that the results produc by the system are similar to real surgical results.

  17. Three-dimensional imaging of absolute blood flow velocity and blood vessel position under low blood flow velocity based on Doppler signal information included in scattered light from red blood cells

    Science.gov (United States)

    Kyoden, Tomoaki; Akiguchi, Shunsuke; Tajiri, Tomoki; Andoh, Tsugunobu; Hachiga, Tadashi

    2017-11-01

    The development of a system for in vivo visualization of occluded distal blood vessels for diabetic patients is the main target of our research. We herein describe two-beam multipoint laser Doppler velocimetry (MLDV), which measures the instantaneous multipoint flow velocity and can be used to observe the blood flow velocity in peripheral blood vessels. By including a motorized stage to shift the measurement points horizontally and in the depth direction while measuring the velocity, the path of the blood vessel in the skin could be observed using blood flow velocity in three-dimensional space. The relationship of the signal power density between the blood vessel and the surrounding tissues was shown and helped us identify the position of the blood vessel. Two-beam MLDV can be used to simultaneously determine the absolute blood flow velocity distribution and identify the blood vessel position in skin.

  18. Gene expression analysis in human breast cancer associated blood vessels.

    Directory of Open Access Journals (Sweden)

    Dylan T Jones

    Full Text Available Angiogenesis is essential for solid tumour growth, whilst the molecular profiles of tumour blood vessels have been reported to be different between cancer types. Although presently available anti-angiogenic strategies are providing some promise for the treatment of some cancers it is perhaps not surprisingly that, none of the anti-angiogenic agents available work on all tumours. Thus, the discovery of novel anti-angiogenic targets, relevant to individual cancer types, is required. Using Affymetrix microarray analysis of laser-captured, CD31-positive blood vessels we have identified 63 genes that are upregulated significantly (5-72 fold in angiogenic blood vessels associated with human invasive ductal carcinoma (IDC of the breast as compared with blood vessels in normal human breast. We tested the angiogenic capacity of a subset of these genes. Genes were selected based on either their known cellular functions, their enriched expression in endothelial cells and/or their sensitivity to anti-VEGF treatment; all features implicating their involvement in angiogenesis. For example, RRM2, a ribonucleotide reductase involved in DNA synthesis, was upregulated 32-fold in IDC-associated blood vessels; ATF1, a nuclear activating transcription factor involved in cellular growth and survival was upregulated 23-fold in IDC-associated blood vessels and HEX-B, a hexosaminidase involved in the breakdown of GM2 gangliosides, was upregulated 8-fold in IDC-associated blood vessels. Furthermore, in silico analysis confirmed that AFT1 and HEX-B also were enriched in endothelial cells when compared with non-endothelial cells. None of these genes have been reported previously to be involved in neovascularisation. However, our data establish that siRNA depletion of Rrm2, Atf1 or Hex-B had significant anti-angiogenic effects in VEGF-stimulated ex vivo mouse aortic ring assays. Overall, our results provide proof-of-principle that our approach can identify a cohort of

  19. Laparoscopic prototype for optical sealing of renal blood vessels

    Science.gov (United States)

    Hardy, Luke A.; Hutchens, Thomas C.; Larson, Eric R.; Gonzalez, David A.; Chang, Chun-Hung; Nau, William H.; Fried, Nathaniel M.

    2017-02-01

    Energy-based, radiofrequency and ultrasonic devices provide rapid sealing of blood vessels during laparoscopic procedures. We are exploring infrared lasers as an alternative for vessel sealing with less collateral thermal damage. Previous studies demonstrated vessel sealing in an in vivo porcine model using a 1470-nm laser. However, the initial prototype was designed for open surgery and featured tissue clasping and light delivery mechanisms incompatible with laparoscopic surgery. In this study, a laparoscopic prototype similar to devices in surgical use was developed, and tests were conducted on porcine renal blood vessels. The 5-mm-OD prototype featured a traditional Maryland jaw configuration. Laser energy was delivered through a 550-μm-core fiber and side-delivery from the lower jaw, with beam dimensions of 18-mm-length x 1.2-mm-width. The 1470-nm diode laser delivered 68 W with 3 s activation time. A total of 69 porcine renal vessels with mean diameter of 3.3 +/- 1.7 mm were tested, ex vivo. Vessels smaller than 5 mm were consistently sealed (48/51) with burst pressures greater than malignant hypertension blood pressure (180 mmHg), averaging 1038 +/- 474 mmHg. Vessels larger than 5 mm were not consistently sealed (6/18), yielding burst pressures of only 174 +/- 221 mmHg. Seal width, thermal damage zone, and thermal spread averaged 1.7 +/- 0.8, 3.4 +/- 0.7, and 1.0 +/- 0.4 mm. A novel optical laparoscopic prototype with 5-mm- OD shaft integrated within a standard Maryland jaw design consistently sealed vessels less than 5 mm with minimal thermal spread. Further in vivo studies are planned to test performance across a variety of vessels and tissues.

  20. Vessel Sampling and Blood Flow Velocity Distribution With Vessel Diameter for Characterizing the Human Bulbar Conjunctival Microvasculature.

    Science.gov (United States)

    Wang, Liang; Yuan, Jin; Jiang, Hong; Yan, Wentao; Cintrón-Colón, Hector R; Perez, Victor L; DeBuc, Delia C; Feuer, William J; Wang, Jianhua

    2016-03-01

    This study determined (1) how many vessels (i.e., the vessel sampling) are needed to reliably characterize the bulbar conjunctival microvasculature and (2) if characteristic information can be obtained from the distribution histogram of the blood flow velocity and vessel diameter. Functional slitlamp biomicroscope was used to image hundreds of venules per subject. The bulbar conjunctiva in five healthy human subjects was imaged on six different locations in the temporal bulbar conjunctiva. The histograms of the diameter and velocity were plotted to examine whether the distribution was normal. Standard errors were calculated from the standard deviation and vessel sample size. The ratio of the standard error of the mean over the population mean was used to determine the sample size cutoff. The velocity was plotted as a function of the vessel diameter to display the distribution of the diameter and velocity. The results showed that the sampling size was approximately 15 vessels, which generated a standard error equivalent to 15% of the population mean from the total vessel population. The distributions of the diameter and velocity were not only unimodal, but also somewhat positively skewed and not normal. The blood flow velocity was related to the vessel diameter (r=0.23, Psampling size of the vessels and the distribution histogram of the blood flow velocity and vessel diameter, which may lead to a better understanding of the human microvascular system of the bulbar conjunctiva.

  1. Heritability of retinal vessel diameters and blood pressure

    DEFF Research Database (Denmark)

    Taarnhøj, Nina C B B; Larsen, Michael; Sander, Birgit

    2006-01-01

    PURPOSE: To assess the relative influence of genetic and environmental effects on retinal vessel diameters and blood pressure in healthy adults, as well as the possible genetic connection between these two characteristics. METHODS: In 55 monozygotic and 50 dizygotic same-sex healthy twin pairs......%-80%) for CRAE, 83% (95% CI: 73%-89%) for CRVE, and 61% (95% CI: 44%-73%) for mean arterial blood pressure (MABP). Retinal artery diameter decreased with increasing age and increasing arterial blood pressure. Mean vessel diameters in the population were 165.8 +/- 14.9 microm for CRAE, 246.2 +/- 17.7 microm...... for CRVE, and 0.67 +/- 0.05 microm for AVR. No significant influence on artery or vein diameters was found for gender, smoking, body mass index (BMI), total cholesterol, fasting blood glucose, or 2-hour oral glucose tolerance test values. CONCLUSIONS: In healthy young adults with normal blood pressure...

  2. Dynamic stroma reorganization drives blood vessel dysmorphia during glioma growth.

    Science.gov (United States)

    Mathivet, Thomas; Bouleti, Claire; Van Woensel, Matthias; Stanchi, Fabio; Verschuere, Tina; Phng, Li-Kun; Dejaegher, Joost; Balcer, Marly; Matsumoto, Ken; Georgieva, Petya B; Belmans, Jochen; Sciot, Raf; Stockmann, Christian; Mazzone, Massimiliano; De Vleeschouwer, Steven; Gerhardt, Holger

    2017-12-01

    Glioma growth and progression are characterized by abundant development of blood vessels that are highly aberrant and poorly functional, with detrimental consequences for drug delivery efficacy. The mechanisms driving this vessel dysmorphia during tumor progression are poorly understood. Using longitudinal intravital imaging in a mouse glioma model, we identify that dynamic sprouting and functional morphogenesis of a highly branched vessel network characterize the initial tumor growth, dramatically changing to vessel expansion, leakage, and loss of branching complexity in the later stages. This vascular phenotype transition was accompanied by recruitment of predominantly pro-inflammatory M1-like macrophages in the early stages, followed by in situ repolarization to M2-like macrophages, which produced VEGF-A and relocate to perivascular areas. A similar enrichment and perivascular accumulation of M2 versus M1 macrophages correlated with vessel dilation and malignancy in human glioma samples of different WHO malignancy grade. Targeting macrophages using anti-CSF1 treatment restored normal blood vessel patterning and function. Combination treatment with chemotherapy showed survival benefit, suggesting that targeting macrophages as the key driver of blood vessel dysmorphia in glioma progression presents opportunities to improve efficacy of chemotherapeutic agents. We propose that vessel dysfunction is not simply a general feature of tumor vessel formation, but rather an emergent property resulting from a dynamic and functional reorganization of the tumor stroma and its angiogenic influences. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

  3. HIFU procedures at moderate intensities-effect of large blood vessels

    International Nuclear Information System (INIS)

    Hariharan, P; Myers, M R; Banerjee, R K

    2007-01-01

    A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams

  4. HIFU procedures at moderate intensities-effect of large blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Hariharan, P [Mechanical, Industrial, and Nuclear Engineering Department, University of Cincinnati, Cincinnati, OH (United States); Myers, M R [Division of Solid and Fluid Mechanics, Center for Devices and Radiological Health, US Food and Drug Administration, 10903 New Hampshire Avenue, Building 62, Silver Spring, MD 20993-0002 (United States); Banerjee, R K [Mechanical, Industrial, and Nuclear Engineering Department, University of Cincinnati, Cincinnati, OH (United States)

    2007-07-21

    A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams.

  5. THE ALGORITHM OF DETERMINATION OF EYE FUNDUS VESSELS BLOOD FLOW CHARACTERISTICS ON VIDEOSEQUENCE

    Directory of Open Access Journals (Sweden)

    O. V. Nedzvedz

    2018-01-01

    Full Text Available The method of determination of the dynamic characteristics like the vessel diameter change, the linear and volume blood velocities in the vessels of the eye fundus is considered. Such characteristics allow to determine blood flow changes in the microvasculature affecting the blood flow in the brain, kidneys and coronary vessels. Developed algorithm includes four stages: the video sequence stabilization, the vessels segmentation with the help of a neural network, the determination of the instantaneous velocity in the vessels based on the optical flow and the analysis of the results.

  6. Improvement of retinal blood vessel detection using morphological component analysis.

    Science.gov (United States)

    Imani, Elaheh; Javidi, Malihe; Pourreza, Hamid-Reza

    2015-03-01

    Detection and quantitative measurement of variations in the retinal blood vessels can help diagnose several diseases including diabetic retinopathy. Intrinsic characteristics of abnormal retinal images make blood vessel detection difficult. The major problem with traditional vessel segmentation algorithms is producing false positive vessels in the presence of diabetic retinopathy lesions. To overcome this problem, a novel scheme for extracting retinal blood vessels based on morphological component analysis (MCA) algorithm is presented in this paper. MCA was developed based on sparse representation of signals. This algorithm assumes that each signal is a linear combination of several morphologically distinct components. In the proposed method, the MCA algorithm with appropriate transforms is adopted to separate vessels and lesions from each other. Afterwards, the Morlet Wavelet Transform is applied to enhance the retinal vessels. The final vessel map is obtained by adaptive thresholding. The performance of the proposed method is measured on the publicly available DRIVE and STARE datasets and compared with several state-of-the-art methods. An accuracy of 0.9523 and 0.9590 has been respectively achieved on the DRIVE and STARE datasets, which are not only greater than most methods, but are also superior to the second human observer's performance. The results show that the proposed method can achieve improved detection in abnormal retinal images and decrease false positive vessels in pathological regions compared to other methods. Also, the robustness of the method in the presence of noise is shown via experimental result. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. 78 FR 68995 - Safety Zone: Vessel Removal From the Oakland Estuary, Alameda, CA

    Science.gov (United States)

    2013-11-18

    ...-AA00 Safety Zone: Vessel Removal From the Oakland Estuary, Alameda, CA AGENCY: Coast Guard, DHS. ACTION... waters of the Oakland Estuary just north of the Park Street Bridge in Alameda, CA in support of the Oakland Estuary Closure for the Vessel Removal Project on November 4, 2013 through November 22, 2013. This...

  8. Aminopeptidase A is a functional target in angiogenic blood vessels.

    Science.gov (United States)

    Marchiò, Serena; Lahdenranta, Johanna; Schlingemann, Reinier O; Valdembri, Donatella; Wesseling, Pieter; Arap, Marco A; Hajitou, Amin; Ozawa, Michael G; Trepel, Martin; Giordano, Ricardo J; Nanus, David M; Dijkman, Henri B P M; Oosterwijk, Egbert; Sidman, Richard L; Cooper, Max D; Bussolino, Federico; Pasqualini, Renata; Arap, Wadih

    2004-02-01

    We show that a membrane-associated protease, aminopeptidase A (APA), is upregulated and enzymatically active in blood vessels of human tumors. To gain mechanistic insight, we evaluated angiogenesis in APA null mice. We found that, although these mice develop normally, they fail to mount the expected angiogenic response to hypoxia or growth factors. We then isolated peptide inhibitors of APA from a peptide library and show that they specifically bind to and inhibit APA, suppress migration and proliferation of endothelial cells, inhibit angiogenesis, and home to tumor blood vessels. Finally, we successfully treated tumor-bearing mice with APA binding peptides or anti-APA blocking monoclonal antibodies. These data show that APA is a regulator of blood vessel formation, and can serve as a functional vascular target.

  9. Automatic detection of blood vessels in retinal images for diabetic retinopathy diagnosis.

    Science.gov (United States)

    Raja, D Siva Sundhara; Vasuki, S

    2015-01-01

    Diabetic retinopathy (DR) is a leading cause of vision loss in diabetic patients. DR is mainly caused due to the damage of retinal blood vessels in the diabetic patients. It is essential to detect and segment the retinal blood vessels for DR detection and diagnosis, which prevents earlier vision loss in diabetic patients. The computer aided automatic detection and segmentation of blood vessels through the elimination of optic disc (OD) region in retina are proposed in this paper. The OD region is segmented using anisotropic diffusion filter and subsequentially the retinal blood vessels are detected using mathematical binary morphological operations. The proposed methodology is tested on two different publicly available datasets and achieved 93.99% sensitivity, 98.37% specificity, 98.08% accuracy in DRIVE dataset and 93.6% sensitivity, 98.96% specificity, and 95.94% accuracy in STARE dataset, respectively.

  10. Subconjunctival Hemorrhage (Broken Blood Vessel in Eye)

    Science.gov (United States)

    Subconjunctival hemorrhage (broken blood vessel in eye) Overview A subconjunctival hemorrhage (sub-kun-JUNK-tih-vul HEM-uh-ruj) ... may not even realize you have a subconjunctival hemorrhage until you look in the mirror and notice ...

  11. Blood Vessel Normalization in the Hamster Oral Cancer Model for Experimental Cancer Therapy Studies

    Energy Technology Data Exchange (ETDEWEB)

    Ana J. Molinari; Romina F. Aromando; Maria E. Itoiz; Marcela A. Garabalino; Andrea Monti Hughes; Elisa M. Heber; Emiliano C. C. Pozzi; David W. Nigg; Veronica A. Trivillin; Amanda E. Schwint

    2012-07-01

    Normalization of tumor blood vessels improves drug and oxygen delivery to cancer cells. The aim of this study was to develop a technique to normalize blood vessels in the hamster cheek pouch model of oral cancer. Materials and Methods: Tumor-bearing hamsters were treated with thalidomide and were compared with controls. Results: Twenty eight hours after treatment with thalidomide, the blood vessels of premalignant tissue observable in vivo became narrower and less tortuous than those of controls; Evans Blue Dye extravasation in tumor was significantly reduced (indicating a reduction in aberrant tumor vascular hyperpermeability that compromises blood flow), and tumor blood vessel morphology in histological sections, labeled for Factor VIII, revealed a significant reduction in compressive forces. These findings indicated blood vessel normalization with a window of 48 h. Conclusion: The technique developed herein has rendered the hamster oral cancer model amenable to research, with the potential benefit of vascular normalization in head and neck cancer therapy.

  12. Regulation of blood vessels by prolactin and vasoinhibins.

    Science.gov (United States)

    Clapp, Carmen; Thebault, Stéphanie; Macotela, Yazmín; Moreno-Carranza, Bibiana; Triebel, Jakob; Martínez de la Escalera, Gonzalo

    2015-01-01

    Prolactin (PRL) stimulates the growth of new blood vessels (angiogenesis) either directly through actions on endothelial cells or indirectly by upregulating proangiogenic factors like vascular endothelial growth factor (VEGF). Moreover, PRL acquires antiangiogenic properties after undergoing proteolytic cleavage to vasoinhibins, a family of PRL fragments (including 16 kDa PRL) with potent antiangiogenic, vasoconstrictive, and antivasopermeability effects. In view of the opposing actions of PRL and vasoinhibins, the regulation of the proteases responsible for specific PRL cleavage represents an efficient mechanism for controlling blood vessel growth and function. This review briefly describes the vascular actions of PRL and vasoinhibins, and addresses how their interplay could help drive biological effects of PRL in the context of health and disease.

  13. Melanopsin mediates light-dependent relaxation in blood vessels.

    Science.gov (United States)

    Sikka, Gautam; Hussmann, G Patrick; Pandey, Deepesh; Cao, Suyi; Hori, Daijiro; Park, Jong Taek; Steppan, Jochen; Kim, Jae Hyung; Barodka, Viachaslau; Myers, Allen C; Santhanam, Lakshmi; Nyhan, Daniel; Halushka, Marc K; Koehler, Raymond C; Snyder, Solomon H; Shimoda, Larissa A; Berkowitz, Dan E

    2014-12-16

    Melanopsin (opsin4; Opn4), a non-image-forming opsin, has been linked to a number of behavioral responses to light, including circadian photo-entrainment, light suppression of activity in nocturnal animals, and alertness in diurnal animals. We report a physiological role for Opn4 in regulating blood vessel function, particularly in the context of photorelaxation. Using PCR, we demonstrate that Opn4 (a classic G protein-coupled receptor) is expressed in blood vessels. Force-tension myography demonstrates that vessels from Opn4(-/-) mice fail to display photorelaxation, which is also inhibited by an Opn4-specific small-molecule inhibitor. The vasorelaxation is wavelength-specific, with a maximal response at ∼430-460 nm. Photorelaxation does not involve endothelial-, nitric oxide-, carbon monoxide-, or cytochrome p450-derived vasoactive prostanoid signaling but is associated with vascular hyperpolarization, as shown by intracellular membrane potential measurements. Signaling is both soluble guanylyl cyclase- and phosphodiesterase 6-dependent but protein kinase G-independent. β-Adrenergic receptor kinase 1 (βARK 1 or GRK2) mediates desensitization of photorelaxation, which is greatly reduced by GRK2 inhibitors. Blue light (455 nM) regulates tail artery vasoreactivity ex vivo and tail blood blood flow in vivo, supporting a potential physiological role for this signaling system. This endogenous opsin-mediated, light-activated molecular switch for vasorelaxation might be harnessed for therapy in diseases in which altered vasoreactivity is a significant pathophysiologic contributor.

  14. An approach to localize the retinal blood vessels using bit planes and centerline detection.

    Science.gov (United States)

    Fraz, M M; Barman, S A; Remagnino, P; Hoppe, A; Basit, A; Uyyanonvara, B; Rudnicka, A R; Owen, C G

    2012-11-01

    The change in morphology, diameter, branching pattern or tortuosity of retinal blood vessels is an important indicator of various clinical disorders of the eye and the body. This paper reports an automated method for segmentation of blood vessels in retinal images. A unique combination of techniques for vessel centerlines detection and morphological bit plane slicing is presented to extract the blood vessel tree from the retinal images. The centerlines are extracted by using the first order derivative of a Gaussian filter in four orientations and then evaluation of derivative signs and average derivative values is performed. Mathematical morphology has emerged as a proficient technique for quantifying the blood vessels in the retina. The shape and orientation map of blood vessels is obtained by applying a multidirectional morphological top-hat operator with a linear structuring element followed by bit plane slicing of the vessel enhanced grayscale image. The centerlines are combined with these maps to obtain the segmented vessel tree. The methodology is tested on three publicly available databases DRIVE, STARE and MESSIDOR. The results demonstrate that the performance of the proposed algorithm is comparable with state of the art techniques in terms of accuracy, sensitivity and specificity. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  15. Correlation between blood and lymphatic vessel density and results of contrast-enhanced spectral mammography.

    Science.gov (United States)

    Luczynska, Elzbieta; Niemiec, Joanna; Ambicka, Aleksandra; Adamczyk, Agnieszka; Walasek, Tomasz; Ryś, Janusz; Sas-Korczyńska, Beata

    2015-09-01

    Contrast-enhanced spectral mammography (CESM) is a novel technique used for detection of tumour vascularity by imaging the moment in which contrast, delivered to the lesion by blood vessels, leaks out of them, and flows out through lymphatic vessels. In our study, we included 174 women for whom spectral mammography was performed for diagnostic purposes. The relationship between enhancement in CESM and blood vessel density (BVD), lymphatic vessel density (LVD) or the percentage of fields with at least one lymphatic vessel (distribution of podoplanin-positive vessels - DPV) and other related parameters was assessed in 55 cases. BVD, LVD and DPV were assessed immunohistochemically, applying podoplanin and CD31/CD34 as markers of lymphatic and blood vessels, respectively. The sensitivity (in detection of malignant lesions) of CESM was 100%, while its specificity - 39%. We found a significant positive correlation between the intensity of enhancement in CESM and BVD (p = 0.007, r = 0.357) and a negative correlation between the intensity of enhancement in CESM and DPV (p = 0.003, r = -0.390). Lesions with the highest enhancement in CESM showed a high number of blood vessels and a low number of lymphatics. 1) CESM is a method characterized by high sensitivity and acceptable specificity; 2) the correlation between CESM results and blood/lymphatic vessel density confirms its utility in detection of tissue angiogenesis and/or lymphangiogenesis.

  16. Distinct mechanisms of relaxation to bioactive components from chamomile species in porcine isolated blood vessels

    International Nuclear Information System (INIS)

    Roberts, R.E.; Allen, S.; Chang, A.P.Y.; Henderson, H.; Hobson, G.C.; Karania, B.; Morgan, K.N.; Pek, A.S.Y.; Raghvani, K.; Shee, C.Y.; Shikotra, J.; Street, E.; Abbas, Z.; Ellis, K.; Heer, J.K.; Alexander, S.P.H.

    2013-01-01

    German chamomile (Matricaria recutita L.), a widely-used herbal medicine, has been reported to have a wide range of biological effects, including smooth muscle relaxation. The aim of this study was to compare the effects of representative compounds from chamomile (apigenin, luteolin, (−)-α-bisabolol, farnesene, umbelliferone; 3–30 μM) on vascular tone using porcine coronary and splenic arteries mounted for isometric tension recording in isolated tissue baths and precontracted with the thromboxane-mimetic U46619. Apigenin, luteolin, and (−)-α-bisabolol produced slow, concentration-dependent relaxations in both the coronary and splenic arteries that were not blocked by inhibition of nitric oxide synthase or potassium channels. Removal of extracellular calcium inhibited the relaxations to all three compounds, and these compounds also inhibited calcium re-addition-evoked contractions, indicating that the relaxation response may be mediated through inhibition of calcium influx. Apigenin and luteolin, but not (−)-α-bisabolol, enhanced the relaxation to the nitric oxide donor sodium nitroprusside, indicating that apigenin and luteolin may act to regulate cyclic GMP levels. Umbelliferone produced a rapid, transient relaxation in the splenic artery, but not the coronary artery, that was inhibited by L-NAME and removal of the endothelium, suggesting an influence on nitric oxide production. Farnesene, at concentrations up to 30 μM, was without effect in either blood vessel. In conclusion, hydroxylated compounds (apigenin, luteolin and (−)-α-bisabolol) found in chamomile all caused a slow relaxation of isolated blood vessels through an effect on calcium influx. Umbelliferone, on the other hand, produced a rapid, transient relaxation dependent upon release of nitric oxide from the endothelium. - Highlights: • Apigenin, luteolin, and (-)-α-bisabolol are present in chamomile. • They produced slow, concentration-dependent relaxations in arteries. • These

  17. Distinct mechanisms of relaxation to bioactive components from chamomile species in porcine isolated blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, R.E., E-mail: Richard.roberts@nottingham.ac.uk; Allen, S.; Chang, A.P.Y.; Henderson, H.; Hobson, G.C.; Karania, B.; Morgan, K.N.; Pek, A.S.Y.; Raghvani, K.; Shee, C.Y.; Shikotra, J.; Street, E.; Abbas, Z.; Ellis, K.; Heer, J.K.; Alexander, S.P.H., E-mail: steve.alexander@nottingham.ac.uk

    2013-11-01

    German chamomile (Matricaria recutita L.), a widely-used herbal medicine, has been reported to have a wide range of biological effects, including smooth muscle relaxation. The aim of this study was to compare the effects of representative compounds from chamomile (apigenin, luteolin, (−)-α-bisabolol, farnesene, umbelliferone; 3–30 μM) on vascular tone using porcine coronary and splenic arteries mounted for isometric tension recording in isolated tissue baths and precontracted with the thromboxane-mimetic U46619. Apigenin, luteolin, and (−)-α-bisabolol produced slow, concentration-dependent relaxations in both the coronary and splenic arteries that were not blocked by inhibition of nitric oxide synthase or potassium channels. Removal of extracellular calcium inhibited the relaxations to all three compounds, and these compounds also inhibited calcium re-addition-evoked contractions, indicating that the relaxation response may be mediated through inhibition of calcium influx. Apigenin and luteolin, but not (−)-α-bisabolol, enhanced the relaxation to the nitric oxide donor sodium nitroprusside, indicating that apigenin and luteolin may act to regulate cyclic GMP levels. Umbelliferone produced a rapid, transient relaxation in the splenic artery, but not the coronary artery, that was inhibited by L-NAME and removal of the endothelium, suggesting an influence on nitric oxide production. Farnesene, at concentrations up to 30 μM, was without effect in either blood vessel. In conclusion, hydroxylated compounds (apigenin, luteolin and (−)-α-bisabolol) found in chamomile all caused a slow relaxation of isolated blood vessels through an effect on calcium influx. Umbelliferone, on the other hand, produced a rapid, transient relaxation dependent upon release of nitric oxide from the endothelium. - Highlights: • Apigenin, luteolin, and (-)-α-bisabolol are present in chamomile. • They produced slow, concentration-dependent relaxations in arteries. • These

  18. Feasibility of Using the Marginal Blood Vessels as Reference Landmarks for CT Colonography

    Science.gov (United States)

    Wei, Zhuoshi; Yao, Jianhua; Wang, Shijun; Liu, Jiamin; Dwyer, Andrew J.; Pickhardt, Perry J.; Nowinski, Wieslaw L.; Summers, Ronald M.

    2015-01-01

    OBJECTIVE The purpose of this study was to show the spatial relationship of the colonic marginal blood vessels and the teniae coli on CT colonography (CTC) and the use of the marginal blood vessels for supine-prone registration of polyps and for determination of proper connectivity of collapsed colonic segments. MATERIALS AND METHODS We manually labeled the marginal blood vessels on 15 CTC examinations. Colon segmentation, centerline extraction, teniae detection, and teniae identification were automatically performed. For assessment of their spatial relationships, the distances from the marginal blood vessels to the three teniae coli and to the colon were measured. Student t tests (paired, two-tailed) were performed to evaluate the differences among these distances. To evaluate the reliability of the marginal vessels as reference points for polyp correlation, we analyzed 20 polyps from 20 additional patients who underwent supine and prone CTC. The average difference of the circumferential polyp position on the supine and prone scans was computed. Student t tests (paired, two-tailed) were performed to evaluate the supine-prone differences of the distance. We performed a study on 10 CTC studies from 10 patients with collapsed colonic segments by manually tracing the marginal blood vessels near the collapsed regions to resolve the ambiguity of the colon path. RESULTS The average distances (± SD) from the marginal blood vessels to the tenia mesocolica, tenia omentalis, and tenia libera were 20.1 ± 3.1 mm (95% CI, 18.5–21.6 mm), 39.5 ± 4.8 mm (37.1–42.0 mm), and 36.9 ± 4.2 mm (34.8–39.1 mm), respectively. Pairwise comparison showed that these distances to the tenia libera and tenia omentalis were significantly different from the distance to the tenia mesocolica (p marginal blood vessels to the colon wall was 15.3 ± 2.0 mm (14.2–16.3 mm). For polyp localization, the average difference of the circumferential polyp position on the supine and prone scans was 9

  19. Customizable engineered blood vessels using 3D printed inserts.

    Science.gov (United States)

    Pinnock, Cameron B; Meier, Elizabeth M; Joshi, Neeraj N; Wu, Bin; Lam, Mai T

    2016-04-15

    Current techniques for tissue engineering blood vessels are not customizable for vascular size variation and vessel wall thickness. These critical parameters vary widely between the different arteries in the human body, and the ability to engineer vessels of varying sizes could increase capabilities for disease modeling and treatment options. We present an innovative method for producing customizable, tissue engineered, self-organizing vascular constructs by replicating a major structural component of blood vessels - the smooth muscle layer, or tunica media. We utilize a unique system combining 3D printed plate inserts to control construct size and shape, and cell sheets supported by a temporary fibrin hydrogel to encourage cellular self-organization into a tubular form resembling a natural artery. To form the vascular construct, 3D printed inserts are adhered to tissue culture plates, fibrin hydrogel is deposited around the inserts, and human aortic smooth muscle cells are then seeded atop the fibrin hydrogel. The gel, aided by the innate contractile properties of the smooth muscle cells, aggregates towards the center post insert, creating a tissue ring of smooth muscle cells. These rings are then stacked into the final tubular construct. Our methodology is robust, easily repeatable and allows for customization of cellular composition, vessel wall thickness, and length of the vessel construct merely by varying the size of the 3D printed inserts. This platform has potential for facilitating more accurate modeling of vascular pathology, serving as a drug discovery tool, or for vessel repair in disease treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Optimized design of an ex-vessel cooling thermosyphon for decay heat removal in SFR

    International Nuclear Information System (INIS)

    Choi, Jae Young; Jeong, Yong Hoon; Song, Sub Lee; Chang, Soon Heung

    2017-01-01

    Passive decay heat removal and sodium fire are two major key issues of nuclear safety in sodium-cooled fast reactor (SFR). Several decay heat removal systems (DHR) were suggested for SFR around the world so far. Those DHRS mainly classified into two concepts: Direct reactor cooling system and ex-vessel cooling system. Direct reactor cooling method represented by PDHRS from PGSFR has disadvantages on its additional in-vessel structure and potential sodium fire risk due to the sodium-filled heat exchanger exposed to air. Contrastively, ex-vessel cooling method represented by RVACS from PRISM has low decay heat removal performance, which cannot be applicable to large scale reactors, generally over 1000 MWth. No passive DHRSs which can solve both side of disadvantages has been suggested yet. The goal of this study was to propose ex-vessel cooling system using two-phase closed thermosyphon to compensate the disadvantages of the past DHRSs. Reference reactor was Innovative SFR (iSFR), a pool-type SFR designed by KAIST and featured by extended core lifetime and increased thermal efficiency. Proposed ex-vessel cooling system consisted of 4 trains of thermosyphons and designed to remove 1% of thermal power with 10% of margin. The scopes of this study were design of proposed passive DHRS, validation of system analysis and optimization of system design. Mercury was selected as working fluid to design ex-vessel thermosyphon in consideration of system geometry, operating temperature and required heat flux. SUS 316 with chrome coated liner was selected as case material to resist against high corrosivity of mercury. Thermosyphon evaporator was covered on the surface of reactor vessel as the geometry of hollow shell filled with mercury. Condenser was consisted of finned tube bundles and was located in isolated water pool, the ultimate heat sink. Operation limits and thermal resistance was estimated to guarantee whether the design was adequate. System analysis was conducted by in

  1. Effect of non-Newtonian characteristics of blood on magnetic particle capture in occluded blood vessel

    Science.gov (United States)

    Bose, Sayan; Banerjee, Moloy

    2015-01-01

    Magnetic nanoparticles drug carriers continue to attract considerable interest for drug targeting in the treatment of cancer and other pathological conditions. Magnetic carrier particles with surface-bound drug molecules are injected into the vascular system upstream from the desired target site, and are captured at the target site via a local applied magnetic field. Herein, a numerical investigation of steady magnetic drug targeting (MDT) using functionalized magnetic micro-spheres in partly occluded blood vessel having a 90° bent is presented considering the effects of non-Newtonian characteristics of blood. An Eulerian-Lagrangian technique is adopted to resolve the hemodynamic flow and the motion of the magnetic particles in the flow using ANSYS FLUENT. An implantable infinitely long cylindrical current carrying conductor is used to create the requisite magnetic field. Targeted transport of the magnetic particles in a partly occluded vessel differs distinctly from the same in a regular unblocked vessel. Parametric investigation is conducted and the influence of the insert configuration and its position from the central plane of the artery (zoffset), particle size (dp) and its magnetic property (χ) and the magnitude of current (I) on the "capture efficiency" (CE) is reported. Analysis shows that there exists an optimum regime of operating parameters for which deposition of the drug carrying magnetic particles in a target zone on the partly occluded vessel wall can be maximized. The results provide useful design bases for in vitro set up for the investigation of MDT in stenosed blood vessels.

  2. Mass Spectrometry and Antibody-Based Characterization of Blood Vessels from Brachylophosaurus canadensis.

    Science.gov (United States)

    Cleland, Timothy P; Schroeter, Elena R; Zamdborg, Leonid; Zheng, Wenxia; Lee, Ji Eun; Tran, John C; Bern, Marshall; Duncan, Michael B; Lebleu, Valerie S; Ahlf, Dorothy R; Thomas, Paul M; Kalluri, Raghu; Kelleher, Neil L; Schweitzer, Mary H

    2015-12-04

    Structures similar to blood vessels in location, morphology, flexibility, and transparency have been recovered after demineralization of multiple dinosaur cortical bone fragments from multiple specimens, some of which are as old as 80 Ma. These structures were hypothesized to be either endogenous to the bone (i.e., of vascular origin) or the result of biofilm colonizing the empty osteonal network after degradation of original organic components. Here, we test the hypothesis that these structures are endogenous and thus retain proteins in common with extant archosaur blood vessels that can be detected with high-resolution mass spectrometry and confirmed by immunofluorescence. Two lines of evidence support this hypothesis. First, peptide sequencing of Brachylophosaurus canadensis blood vessel extracts is consistent with peptides comprising extant archosaurian blood vessels and is not consistent with a bacterial, cellular slime mold, or fungal origin. Second, proteins identified by mass spectrometry can be localized to the tissues using antibodies specific to these proteins, validating their identity. Data are available via ProteomeXchange with identifier PXD001738.

  3. Leukemic Cells "Gas Up" Leaky Bone Marrow Blood Vessels.

    Science.gov (United States)

    Itkin, Tomer; Rafii, Shahin

    2017-09-11

    In this issue of Cancer Cell, Passaro et al. demonstrate how leukemia through aberrant induction of reactive oxygen species and nitric oxide production trigger marrow vessel leakiness, instigating pro-leukemic function. Disrupted tumor blood vessels promote exhaustion of non-malignant stem and progenitor cells and may facilitate leukemia relapse following chemotherapeutic treatment. Copyright © 2017. Published by Elsevier Inc.

  4. Peptide-Mediated Liposomal Drug Delivery System Targeting Tumor Blood Vessels in Anticancer Therapy

    Directory of Open Access Journals (Sweden)

    Han-Chung Wu

    2010-01-01

    Full Text Available Solid tumors are known to recruit new blood vessels to support their growth. Therefore, unique molecules expressed on tumor endothelial cells can function as targets for the antiangiogenic therapy of cancer. Current efforts are focusing on developing therapeutic agents capable of specifically targeting cancer cells and tumor-associated microenvironments including tumor blood vessels. These therapies hold the promise of high efficacy and low toxicity. One recognized strategy for improving the therapeutic effectiveness of conventional chemotherapeutics is to encapsulate anticancer drugs into targeting liposomes that bind to the cell surface receptors expressed on tumor-associated endothelial cells. These anti-angiogenic drug delivery systems could be used to target both tumor blood vessels as well as the tumor cells, themselves. This article reviews the mechanisms and advantages of various present and potential methods using peptide-conjugated liposomes to specifically destroy tumor blood vessels in anticancer therapy.

  5. Parametrically defined cerebral blood vessels as non-invasive blood input functions for brain PET studies

    International Nuclear Information System (INIS)

    Asselin, Marie-Claude; Cunningham, Vincent J; Amano, Shigeko; Gunn, Roger N; Nahmias, Claude

    2004-01-01

    A non-invasive alternative to arterial blood sampling for the generation of a blood input function for brain positron emission tomography (PET) studies is presented. The method aims to extract the dimensions of the blood vessel directly from PET images and to simultaneously correct the radioactivity concentration for partial volume and spillover. This involves simulation of the tomographic imaging process to generate images of different blood vessel and background geometries and selecting the one that best fits, in a least-squares sense, the acquired PET image. A phantom experiment was conducted to validate the method which was then applied to eight subjects injected with 6-[ 18 F]fluoro-L-DOPA and one subject injected with [ 11 C]CO-labelled red blood cells. In the phantom study, the diameter of syringes filled with an 11 C solution and inserted into a water-filled cylinder were estimated with an accuracy of half a pixel (1 mm). The radioactivity concentration was recovered to 100 ± 4% in the 8.7 mm diameter syringe, the one that most closely approximated the superior sagittal sinus. In the human studies, the method systematically overestimated the calibre of the superior sagittal sinus by 2-3 mm compared to measurements made in magnetic resonance venograms on the same subjects. Sources of discrepancies related to the anatomy of the blood vessel were found not to be fundamental limitations to the applicability of the method to human subjects. This method has the potential to provide accurate quantification of blood radioactivity concentration from PET images without the need for blood samples, corrections for delay and dispersion, co-registered anatomical images, or manually defined regions of interest

  6. Thermographic venous blood flow characterization with external cooling stimulation

    Science.gov (United States)

    Saxena, Ashish; Ng, E. Y. K.; Raman, Vignesh

    2018-05-01

    Experimental characterization of blood flow in a human forearm is done with the application of continuous external cooling based active thermography method. Qualitative and quantitative detection of the blood vessel in a thermal image is done, along with the evaluation of blood vessel diameter, blood flow direction, and velocity in the target blood vessel. Subtraction based image manipulation is performed to enhance the feature contrast of the thermal image acquired after the removal of external cooling. To demonstrate the effect of occlusion diseases (obstruction), an external cuff based occlusion is applied after the removal of cooling and its effect on the skin rewarming is studied. Using external cooling, a transit time method based blood flow velocity estimation is done. From the results obtained, it is evident that an external cooling based active thermography method can be used to develop a diagnosis tool for superficial blood vessel diseases.

  7. Towards cavitation-enhanced permeability in blood vessel on a chip

    Science.gov (United States)

    De Luca, R.; Silvani, G.; Scognamiglio, C.; Sinibaldi, G.; Peruzzi, G.; Chinappi, M.; Kiani, M. F.; Casciola, C. M.

    2017-08-01

    The development of targeted delivery systems releasing pharmaceutical agents directly at the desired site of action may improve their therapeutic efficiency while minimizing damage to healthy tissues, toxicity to the patient and drug waste. In this context, we have developed a bio-inspired microdevice mimicking the tumour microvasculature which represents a valuable tool for assessing the enhancement of blood vessel permeability due to cavitation. This novel system allows us to investigate the effects of ultrasound-driven microbubbles that temporarily open the endothelial intercellular junctions allowing drug to extravasate blood vessels into tumour tissues. The blood vessel on a chip consists of a tissue chamber and two independent vascular channels (width 200 µm, height 100 µm, length 2762 µm) cultured with endothelial cells placed side-by-side and separated by a series of 3 µm pores. Its geometry and dimensions mimic the three-dimensional morphology, size and flow characteristics of microvessels in vivo. The early stage of this project had a twofold objective: 1. To define the protocol for culturing of Human Umbilical Vein Endothelial Cells (HUVECs) within the vascular channel; 2. To develop a fluorescence based microscopy technique for measuring permeability. We have developed a reliable and reproducible protocol to culture endothelial cells within the artificial vessels in a realistic manner: HUVECs show the typical elongated shape in the direction of flow, exhibit tight junction formation and form a continuous layer with a central lumen that completely covers the channels wall. As expected, the permeability of cell-free device is higher than the one cultured with HUVECs in the vascular channels. The proposed blood vessel on a chip and the permeability measurement protocol have a significant potential to allow for the study of cavitation-enhanced permeability of the endothelium and improve efficiency in screening drug delivery systems.

  8. Wide-field absolute transverse blood flow velocity mapping in vessel centerline

    Science.gov (United States)

    Wu, Nanshou; Wang, Lei; Zhu, Bifeng; Guan, Caizhong; Wang, Mingyi; Han, Dingan; Tan, Haishu; Zeng, Yaguang

    2018-02-01

    We propose a wide-field absolute transverse blood flow velocity measurement method in vessel centerline based on absorption intensity fluctuation modulation effect. The difference between the light absorption capacities of red blood cells and background tissue under low-coherence illumination is utilized to realize the instantaneous and average wide-field optical angiography images. The absolute fuzzy connection algorithm is used for vessel centerline extraction from the average wide-field optical angiography. The absolute transverse velocity in the vessel centerline is then measured by a cross-correlation analysis according to instantaneous modulation depth signal. The proposed method promises to contribute to the treatment of diseases, such as those related to anemia or thrombosis.

  9. Polysaccharides from astragali radix restore chemical-induced blood vessel loss in zebrafish

    Science.gov (United States)

    2012-01-01

    Background Astragali Radix has been used widely for the treatment of cardiovascular and cerebrovascular diseases, and to enhance endurance and stamina in traditional Chinese medicine (TCM) for over 2000 years. The polysaccharide constituents of Astragali Radix (ARP) are considered as one of the major constituents contributing to the multiple pharmacological effects of this medicinal plant. The purpose of the study is to evaluate the vascular regenerative activities of ARPs in a chemically-induced blood vessel loss model in zebrafish. Methods Blood vessel loss was induced in both Tg(fli-1a:EGFP)y1 and Tg(fli-1a:nEGFP)y7 embryos by administration of 300 nM VEGFR tyrosine kinase inhibitor II (VRI) for 3 h at 24 hpf (hour post-fertilization). Then, the blood vessel damaged zebrafish were treated with ARPs for 21 h and 45 h after VRI withdrawal. Morphological changes in intersegmental vessels (ISVs) of zebrafish larvae were observed under the fluorescence microscope and measured quantitatively. The rescue effect of ARPs in the zebrafish models was validated by measuring the relative mRNA expressions of Kdrl, Kdr and Flt-1 using real-time PCR. Results Two polysaccharide fractions, P4 (50000 D 0.1 μm), isolated from Astragali Radix by ultrafiltration, produced a significant and dose-dependent recovery in VRI-induced blood vessel loss in zebrafish. Furthermore, the down-regulation of Flk-1 and Flt-1 mRNA expression induced by VRI was reversed by treatment with P4. Conclusion The present study demonstrates that P4 isolated from Astragali Radix reduces VRI-induced blood vessel loss in zebrafish. These findings support the hypothesis that polysaccharides are one of the active constituents in Astragali Radix, contributing to its beneficial effect on treatment of diseases associated with a deficiency in angiogenesis. PMID:22357377

  10. Fetal blood vessel count increases in compensation of hypoxia in premature placentas

    Directory of Open Access Journals (Sweden)

    K. Kartini

    2015-04-01

    Full Text Available Background Prematurity refers to live births before 37 weeks of gestation, wherein the baby is born before the body and its organ systems achieve perfect maturity, and this disorder is still a global problem. The high incidence of prematurity is a problem in developing and also in developed countries. Certain conditions accompanying pregnancies like preeclampsia, infection, and placental insufficiency, may trigger uterine hypoxia, causing premature birth. The placental condition is related to the intra-uterine fetal condition. In prolonged placental hypoxia, there occurs a compensatory mechanism, i.e. an increase in placental angiogenesis. This study aimed to evaluate the effect of hypoxia on fetal blood vessel count as compensatory mechanism for tissue hypoxia. Methods An observational-analytical cross-sectional design using paraffin blocks of conserved premature placentas, comprising 31 samples of hypoxic premature placentas and 28 samples of non-hypoxic premature placentas, selected using non-random consecutive sampling. The samples were made into slides and stained with hematoxylin-eosin for assessment of histological structure, including fetal blood vessel count and integrity, villus conditions, syncytiotrophoblastic nuclear changes, and syncytiotrophoblastic nuclear aggregation. Mann-Whitney test was used to compare the difference of blood vessel count between groups. Results Assessment of histological structure showed a significant increase in fetal blood vessel count in the hypoxic group [8.00 (5-15] as compared with the non-hypoxic group [7.50 (3-15]. Conclusion The hypoxia in premature placentas caused an increase in the number of fetal blood vessels as a form of compensation for disturbed oxygen homeostasis.

  11. Fetal blood vessel count increases in compensation of hypoxia in premature placentas

    Directory of Open Access Journals (Sweden)

    K Kartini

    2016-02-01

    Full Text Available BACKGROUND Prematurity refers to live births before 37 weeks of gestation, wherein the baby is born before the body and its organ systems achieve perfect maturity, and this disorder is still a global problem. The high incidence of prematurity is a problem in developing and also in developed countries. Certain conditions accompanying pregnancies like preeclampsia, infection, and placental insufficiency, may trigger uterine hypoxia, causing premature birth. The placental condition is related to the intra-uterine fetal condition. In prolonged placental hypoxia, there occurs a compensatory mechanism, i.e. an increase in placental angiogenesis. This study aimed to evaluate the effect of hypoxia on fetal blood vessel count as compensatory mechanism for tissue hypoxia. METHODS An observational-analytical cross-sectional design using paraffin blocks of conserved premature placentas, comprising 31 samples of hypoxic premature placentas and 28 samples of non-hypoxic premature placentas, selected using non-random consecutive sampling. The samples were made into slides and stained with hematoxylin-eosin for assessment of histological structure, including fetal blood vessel count and integrity, villus conditions, syncytiotrophoblastic nuclear changes, and syncytiotrophoblastic nuclear aggregation. Mann-Whitney test was used to compare the difference of blood vessel count between groups. RESULTS Assessment of histological structure showed a significant increase in fetal blood vessel count in the hypoxic group [8.00 (5-15] as compared with the non-hypoxic group [7.50 (3-15]. CONCLUSION The hypoxia in premature placentas caused an increase in the number of fetal blood vessels as a form of compensation for disturbed oxygen homeostasis.

  12. Bio-Adaption between Magnesium Alloy Stent and the Blood Vessel: A Review.

    Science.gov (United States)

    Ma, Jun; Zhao, Nan; Betts, Lexxus; Zhu, Donghui

    2016-09-01

    Biodegradable magnesium (Mg) alloy stents are the most promising next generation of bio-absorbable stents. In this article, we summarized the progresses on the in vitro studies, animal testing and clinical trials of biodegradable Mg alloy stents in the past decades. These exciting findings led us to propose the importance of the concept "bio-adaption" between the Mg alloy stent and the local tissue microenvironment after implantation. The healing responses of stented blood vessel can be generally described in three overlapping phases: inflammation, granulation and remodeling. The ideal bio-adaption of the Mg alloy stent, once implanted into the blood vessel, needs to be a reasonable function of the time and the space/dimension. First, a very slow degeneration of mechanical support is expected in the initial four months in order to provide sufficient mechanical support to the injured vessels. Although it is still arguable whether full mechanical support in stented lesions is mandatory during the first four months after implantation, it would certainly be a safety design parameter and a benchmark for regulatory evaluations based on the fact that there is insufficient human in vivo data available, especially the vessel wall mechanical properties during the healing/remodeling phase. Second, once the Mg alloy stent being degraded, the void space will be filled by the regenerated blood vessel tissues. The degradation of the Mg alloy stent should be 100% completed with no residues, and the degradation products (e.g., ions and hydrogen) will be helpful for the tissue reconstruction of the blood vessel. Toward this target, some future research perspectives are also discussed.

  13. Accuracy of geometrical modelling of heat transfer from tissue to blood vessels

    NARCIS (Netherlands)

    Leeuwen, van G.M.J.; Kotte, A.N.T.J.; Bree, de J.; Koijk, van der J.F.; Crezee, J.; Lagendijk, J.J.W.

    1997-01-01

    We have developed a thermal model in which blood vessels are described as geometrical objects, 3D curves with associated diameters. Here the behaviour of the model is examined for low resolutions compared with the vessel diameter and for strongly curved vessels. The tests include a single straight

  14. Bone marrow blood vessel ossification and "microvascular dead space" in rat and human long bone.

    Science.gov (United States)

    Prisby, Rhonda D

    2014-07-01

    Severe calcification of the bone microvascular network was observed in rats, whereby the bone marrow blood vessels appeared ossified. This study sought to characterize the magnitude of ossification in relation to patent blood vessels and adipocyte content in femoral diaphyses. Additionally, this study confirmed the presence of ossified vessels in patients with arteriosclerotic vascular disease and peripheral vascular disease and cellulitis. Young (4-6 month; n=8) and old (22-24 month; n=8) male Fischer-344 rats were perfused with barium sulfate to visualize patent bone marrow blood vessels. Femoral shafts were processed for bone histomorphometry to quantify ossified (Goldner's Trichrome) and calcified (Alizarin Red) vessels. Adipocyte content was also determined. Additional femora (n=5/age group) were scanned via μCT to quantify microvascular ossification. Bone marrow blood vessels from the rats and the human patients were also isolated and examined via microscopy. Ossified vessels (rats and humans) had osteocyte lacunae on the vessel surfaces and "normal" vessels were transitioning into bone. The volume of ossified vessels was 4800% higher (pnecrosis. Progression of bone microvascular ossification may provide the common link associated with age-related changes in bone and bone marrow. The clinical implications may be evident in the difficulties treating bone disease in the elderly. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Effect of blood vessels on light distribution in optogenetic stimulation of cortex.

    Science.gov (United States)

    Azimipour, Mehdi; Atry, Farid; Pashaie, Ramin

    2015-05-15

    In this Letter, the impact of blood vessels on light distribution during photostimulation of cortical tissue in small rodents is investigated. Brain optical properties were extracted using a double-integrating sphere setup, and optical coherence tomography was used to image cortical vessels and capillaries to generate a three-dimensional angiogram of the cortex. By combining these two datasets, a complete volumetric structure of the cortical tissue was developed and linked to a Monte Carlo code which simulates light propagation in this inhomogeneous structure and illustrates the effect of blood vessels on the penetration depth and pattern preservation in optogenetic stimulation.

  16. Development of glia and blood vessels in the internal capsule of rats.

    Science.gov (United States)

    Earle, K L; Mitrofanis, J

    1998-02-01

    We have explored two aspects of internal capsule development that have not been described previously, namely, the development of glia and of blood vessels. To these ends, we used antibodies to glial fibrillary acidic protein (GFAP) and to vimentin (to identify astrocytes and to radial glia) and Griffonia simplicifolia (lectin; to identify microglia and blood vessels). Further, we made intracardiac injections of Evans Blue to examine the permeability of this dye in the vessels of the internal capsule during neonatal development. Our results show that large numbers of radial glia, astrocytes and microglia are not labelled with these markers in the white matter of the internal capsule until about birth; very few are labelled earlier, during the critical stages of corticofugal and corticopetal axonal ingrowth (E15-E20). The large glial labelling in the internal capsule at birth is accompanied by a dense vascular innervation of the capsule; as with the glia, very few labelled patent vessels are seen earlier. After intracardiac injections of Evans Blue, we find that the blood vessels of the internal capsule are not particularly permeable to Evans Blue. At each age examined (P0, P5, P15), blood vessels are outlined very clearly and there is no diffuse haze of fluorescence within the extracellular space, which is indicative of a leaky vessel. There are three striking differences between the glial environment of the internal capsule and that of the adjacent thalamus. First, the internal capsule is never rich with radial glial fibres (vimentin- and GFAP-immunoreactive) during development (except at P0), whereas the thalamus has many radial fibres from very early development (E15-E17). Second, astrocytes (vimentin- and GFAP-immunoreactive) first become apparent in the internal capsule (E20-P0) well before they do in the thalamus (P15). Third, the internal capsule houses a large transient population of amoeboid microglia (P0-P22), whereas the thalamus does not; only ramified

  17. Tracking blood vessels in human forearms using visual servoing

    DEFF Research Database (Denmark)

    Savarimuthu, Thiusius Rajeeth; Ellekilde, Lars-Peter; Hansen, Morten

    compensation. By using images taken with near-infrared light to locate the blood vessels in a human forearm and using the same images to detects movements of the arm, this paper shows that it is possible make a robot arm, potentially equipped with a needle for drawing the blood, compensate for the movements......Drawing an average of more than 2 blood sample per Danish citizen per year increases the demand for an automatic blood sampling method. This paper presents a proof of concept to one of the main challenges in making a fully automated blood sampling procedure, namely: the patient movement...

  18. Acute effect of gamma-irradiation on blood vessels of the eye

    International Nuclear Information System (INIS)

    Matsushima, Hideno

    1977-01-01

    Radiation injuries to the eye were studied by examining the alteration of fine vasculature of irradiated rabbit eyes, by referring to the usual clinical findings, fundus photography, microangiography, and histological sections. These experiments were performed by using white rabbits whose eyes were locally irradiated with a single dose of 500, 1000, 2000, 3000, and 5000 R of 60 Co-γ-ray. The eyes were observed periodically for a period up to 10 weeks after irradiation, and the following results were obtained: 1) Radiation damage to the blood vessels was maximum around 6 weeks after irradiation for doses less than 2000 R, and the damage appeared to be reversible. 2) When given more than 3000 R irradiation, alteration of the blood vessels continued increasing for 10 weeks with no evidence of recovery. Experimental evidence from these studies supports the hypothesis that the degree of radiation injury of the eye depends highly on the damage to blood vessels serving each structure of the eye. (auth.)

  19. Blood vessel damage correlated with irradiance for in vivo vascular targeted photodynamic therapy

    Science.gov (United States)

    Zhang, Jinde; Tan, Zou; Niu, Xiangyu; Lin, Linsheng; Lin, Huiyun; Li, Buhong

    2016-10-01

    Vascular targeted photodynamic therapy (V-PDT) has been widely utilized for the prevention or treatment of vascular-related diseases, including age-related macular degeneration, port-wine stains and prostate cancer. In order to quantitative assessment the blood vessel damage during V-PDT, nude mice were implanted with Titanium dorsal skin window chambers for in vivo V-PDT studies. For treatments, various irradiances including 50, 75, 100 and 200 mW/cm2 provided by a 532 nm semiconductor laser were performed with the same total light dose of 30 J/cm2 after the mice were intravenously injection of Rose Bengal for 25 mg/Kg body weight. Laser speckle imaging and microscope were used to monitor blood flow dynamics and vessel constriction during and after V-PDT, respectively. The V-PDT induced vessel damages between different groups were compared. The results show that significant difference in blood vessel damage was found between the lower irradiances (50, 75 and 100 mW/cm2) and higher irradiance (200 mW/cm2), and the blood vessel damage induced by V-PDT is positively correlated with irradiance. This study implies that the optimization of irradiance is required for enhancing V-PDT therapeutic efficiency.

  20. Mathematical modelling for trajectories of magnetic nanoparticles in a blood vessel under magnetic field

    International Nuclear Information System (INIS)

    Sharma, Shashi; Katiyar, V.K.; Singh, Uaday

    2015-01-01

    A mathematical model is developed to describe the trajectories of a cluster of magnetic nanoparticles in a blood vessel for the application of magnetic drug targeting (MDT). The magnetic nanoparticles are injected into a blood vessel upstream from a malignant tissue and are captured at the tumour site with help of an applied magnetic field. The applied field is produced by a rare earth cylindrical magnet positioned outside the body. All forces expected to significantly affect the transport of nanoparticles were incorporated, including magnetization force, drag force and buoyancy force. The results show that particles are slow down and captured under the influence of magnetic force, which is responsible to attract the magnetic particles towards the magnet. It is optimized that all particles are captured either before or at the centre of the magnet (z≤0) when blood vessel is very close proximity to the magnet (d=2.5 cm). However, as the distance between blood vessel and magnet (d) increases (above 4.5 cm), the magnetic nanoparticles particles become free and they flow away down the blood vessel. Further, the present model results are validated by the simulations performed using the finite element based COMSOL software. - Highlights: • A mathematical model is developed to describe the trajectories of magnetic nanoparticles. • The dominant magnetic, drag and buoyancy forces are considered. • All particles are captured when distance between blood vessel and magnet (d) is up to 4.5 cm. • Further increase in d value (above 4.5 cm) results the free movement of magnetic particles

  1. Imaging Blood Vessel Morphology in Skin

    DEFF Research Database (Denmark)

    Schuh, Sandra; Holmes, Jon; Ulrich, Martina

    2017-01-01

    Conventional optical coherence tomography (OCT) enables the visualization of morphological changes of skin cancer. The use of OCT in the diagnostic investigation and in the therapy decision of non-melanoma skin cancer and other skin changes is already established, and has found its way into routine...... practice. With the development of speckle-variance OCT, also named dynamic OCT (D-OCT), the vascular architecture and the blood flow of the skin can be displayed in vivo and in 3D. This novel angiographic variant of OCT offers the ability to visualize and measure vessel morphology providing a new insight...... into healthy, inflammatory and neoplastic skin lesions such as malignant melanoma. This review focuses on the possibilities of using D-OCT on healthy and diseased skin. We suggest and illustrate key diagnostic characteristics by analyzing the initial publications and preliminary unpublished data on vessel...

  2. Bio-Adaption between Magnesium Alloy Stent and the Blood Vessel: A Review

    Science.gov (United States)

    Ma, Jun; Zhao, Nan; Betts, Lexxus; Zhu, Donghui

    2016-01-01

    Biodegradable magnesium (Mg) alloy stents are the most promising next generation of bio-absorbable stents. In this article, we summarized the progresses on the in vitro studies, animal testing and clinical trials of biodegradable Mg alloy stents in the past decades. These exciting findings led us to propose the importance of the concept “bio-adaption” between the Mg alloy stent and the local tissue microenvironment after implantation. The healing responses of stented blood vessel can be generally described in three overlapping phases: inflammation, granulation and remodeling. The ideal bio-adaption of the Mg alloy stent, once implanted into the blood vessel, needs to be a reasonable function of the time and the space/dimension. First, a very slow degeneration of mechanical support is expected in the initial four months in order to provide sufficient mechanical support to the injured vessels. Although it is still arguable whether full mechanical support in stented lesions is mandatory during the first four months after implantation, it would certainly be a safety design parameter and a benchmark for regulatory evaluations based on the fact that there is insufficient human in vivo data available, especially the vessel wall mechanical properties during the healing/remodeling phase. Second, once the Mg alloy stent being degraded, the void space will be filled by the regenerated blood vessel tissues. The degradation of the Mg alloy stent should be 100% completed with no residues, and the degradation products (e.g., ions and hydrogen) will be helpful for the tissue reconstruction of the blood vessel. Toward this target, some future research perspectives are also discussed. PMID:27698548

  3. Bone Marrow Blood Vessel Ossification and “Microvascular Dead Space” in Rat and Human Long Bone

    Science.gov (United States)

    Prisby, Rhonda D.

    2014-01-01

    Severe calcification of the bone microvascular network was observed in rats, whereby the bone marrow blood vessels appeared ossified. This study sought to characterize the magnitude of ossification in relation to patent blood vessels and adipocyte content in femoral diaphyses. Additionally, this study confirmed the presence of ossified vessels in patients with arteriosclerotic vascular disease and peripheral vascular disease and cellulitis. Young (4–6 mon; n=8) and old (22–24 mon; n=8) male Fischer-344 rats were perfused with barium sulfate to visualize patent bone marrow blood vessels. Femoral shafts were processed for bone histomorphometry to quantify ossified (Goldner’s Trichrome) and calcified (Alizarin Red) vessels. Adipocyte content was also determined. Additional femora (n=5/age group) were scanned via µCT to quantify microvascular ossification. Bone marrow blood vessels from rats and the human patients were also isolated and examined via microscopy. Ossified vessels (rats and humans) had osteocyte lacunae on the vessel surfaces and “normal” vessels were transitioning into bone. The volume of ossified vessels was 4800% higher (p necrosis. The progression of bone microvascular ossification may provide the common link associated with age-related changes in bone and bone marrow. The clinical implications may be evident in the difficulties treating bone disease in the elderly. PMID:24680721

  4. Tissue Engineering of Blood Vessels: Functional Requirements, Progress, and Future Challenges.

    Science.gov (United States)

    Kumar, Vivek A; Brewster, Luke P; Caves, Jeffrey M; Chaikof, Elliot L

    2011-09-01

    Vascular disease results in the decreased utility and decreased availability of autologus vascular tissue for small diameter (requires combined approaches from biomaterials science, cell biology, and translational medicine to develop feasible solutions with the requisite mechanical support, a non-fouling surface for blood flow, and tissue regeneration. Over the past two decades interest in blood vessel tissue engineering has soared on a global scale, resulting in the first clinical implants of multiple technologies, steady progress with several other systems, and critical lessons-learned. This review will highlight the current inadequacies of autologus and synthetic grafts, the engineering requirements for implantation of tissue-engineered grafts, and the current status of tissue-engineered blood vessel research.

  5. A numerical analysis on the curved bileaflet Mechanical Heart Valve (MHV) : leaflet motion and blood flow in an elastic blood vessel

    International Nuclear Information System (INIS)

    Bang, Jin Seok; Kim, Chang Nyung; Choi, Choeng Ryul

    2005-01-01

    In blood flow passing through the Mechanical Heart Valve (MHV) and elastic blood vessel, hemolysis and platelet activation causing thrombus formation can be seen owing to the shear stress in the blood. Also, fracture and deformation of leaflets can be observed depending on the shape and material properties of the leaflets which is opened and closed in a cycle. Hence, comprehensive study is needed on the hemodynamics which is associated with the motion of leaflet and elastic blood vessel in terms of fluid-structure interaction. In this paper, a numerical analysis has been performed for a three-dimensional pulsatile blood flow associated with the elastic blood vessel and curved bileaflet for multiple cycles in light of fluid-structure interaction. From this analysis fluttering phenomenon and rebound of the leaflet have been observed and recirculation and regurgitation have been found in the flow fields of the blood. Also, the pressure distribution and the radial displacement of the elastic blood vessel have been obtained. The motion of the leaflet and flow fields of the blood have shown similar tendency compared with the previous experiments carried out in other studies. The present study can contribute to the design methodology for the curved bileaflet mechanical heart valve. Furthermore, the proposed fluid-structure interaction method will be effectively used in various fields where the interaction between fluid flow and structure are involved

  6. Proteomic profiling of tissue-engineered blood vessel walls constructed by adipose-derived stem cells.

    Science.gov (United States)

    Wang, Chen; Guo, Fangfang; Zhou, Heng; Zhang, Yun; Xiao, Zhigang; Cui, Lei

    2013-02-01

    Adipose-derived stem cells (ASCs) can differentiate into smooth muscle cells and have been engineered into elastic small diameter blood vessel walls in vitro. However, the mechanisms involved in the development of three-dimensional (3D) vascular tissue remain poorly understood. The present study analyzed protein expression profiles of engineered blood vessel walls constructed by human ASCs using methods of two-dimensional gel electrophoresis (2DE) and mass spectrometry (MS). These results were compared to normal arterial walls. A total of 1701±15 and 1265±26 protein spots from normal and engineered blood vessel wall extractions were detected by 2DE, respectively. A total of 20 spots with at least 2.0-fold changes in expression were identified, and 38 differently expressed proteins were identified by 2D electrophoresis and ion trap MS. These proteins were classified into seven functional categories: cellular organization, energy, signaling pathway, enzyme, anchored protein, cell apoptosis/defense, and others. These results demonstrated that 2DE, followed by ion trap MS, could be successfully utilized to characterize the proteome of vascular tissue, including tissue-engineered vessels. The method could also be employed to achieve a better understanding of differentiated smooth muscle protein expression in vitro. These results provide a basis for comparative studies of protein expression in vascular smooth muscles of different origin and could provide a better understanding of the mechanisms of action needed for constructing blood vessels that exhibit properties consistent with normal blood vessels.

  7. Effects of Blood-cooling and Stasis-removing Formula on Hemorheology in Rats with Acute Blood Stasis

    Directory of Open Access Journals (Sweden)

    Songyi Ning

    2013-06-01

    Full Text Available Objective: To investigate the effects of blood-cooling and stasis-removing formula on hemorheology in rats with acute blood stasis induced by mutifactor stimuli. Methods: The selected SD rats orally took blood-cooling and stasis-removing granule for six days, then the model of acute blood stasis was prepared on the fifth day by injection of epinephrine combined with ice-water bath. The variations of blood-cooling and stasis-removing granule on hemorheology were detected. Results: The high-dose group of blood-cooling and stasis-removing formula can decrease plasma viscosity in rats with acute blood stasis, and obviously reduce the blood viscosity under the condition of shear rates (200s-1, 30s-1, 5s-1, 1s-1 (P < 0.01, P < 0.05. The middle-dose group can decrease the blood viscosity under the condition of shear rate (30s-1 (P < 0.05. Conclusion: Blood-cooling and stasis-removing formula can improve abnormal hemorheology in rats with acute blood stasis.

  8. A Computational Model Predicting Disruption of Blood Vessel Development

    Science.gov (United States)

    Vascular development is a complex process regulated by dynamic biological networks that vary in topology and state across different tissues and developmental stages. Signals regulating de novo blood vessel formation (vasculogenesis) and remodeling (angiogenesis) come from a varie...

  9. Classic beta-amyloid deposits cluster around large diameter blood vessels rather than capillaries in sporadic Alzheimer's disease.

    Science.gov (United States)

    Armstrong, Richard A

    2006-11-01

    Various hypotheses could explain the relationship between beta-amyloid (Abeta) deposition and the vasculature in Alzheimer's disease (AD). Amyloid deposition may reduce capillary density, affect endothelial cells of blood vessels, result in diffusion from blood vessels, or interfere with the perivascular clearance mechanism. Hence, the spatial pattern of the classic ('cored') type of Abeta deposit was studied in the upper laminae (I,II/III) of the superior frontal gyrus in nine cases of sporadic AD (SAD). Sections were immunostained with antibodies against Abeta and with collagen IV to study the relationships between the spatial distribution of the classic deposits and the blood vessel profiles. Both the classic deposits and blood vessel profiles were distributed in clusters. In all cases, there was a positive spatial correlation between the clusters of the classic deposits and the larger diameter (>10 microm) blood vessel profiles and especially the vertically penetrating arterioles. In only 1 case, was there a significant spatial correlation between the clusters of the classic deposits and the smaller diameter (upper laminae of the frontal cortex. This aggregation could result from diffusion of proteins from blood vessels or from overloading the system of perivascular clearance from the brain.

  10. Optics based signal processing methods for intraoperative blood vessel detection and quantification in real time (Conference Presentation)

    Science.gov (United States)

    Chaturvedi, Amal; Shukair, Shetha A.; Le Rolland, Paul; Vijayvergia, Mayank; Subramanian, Hariharan; Gunn, Jonathan W.

    2016-03-01

    Minimally invasive operations require surgeons to make difficult cuts to blood vessels and other tissues with impaired tactile and visual feedback. This leads to inadvertent cuts to blood vessels hidden beneath tissue, causing serious health risks to patients and a non-reimbursable financial burden to hospitals. Intraoperative imaging technologies have been developed, but these expensive systems can be cumbersome and provide only a high-level view of blood vessel networks. In this research, we propose a lean reflectance-based system, comprised of a dual wavelength LED, photodiode, and novel signal processing algorithms for rapid vessel characterization. Since this system takes advantage of the inherent pulsatile light absorption characteristics of blood vessels, no contrast agent is required for its ability to detect the presence of a blood vessel buried deep inside any tissue type (up to a cm) in real time. Once a vessel is detected, the system is able to estimate the distance of the vessel from the probe and the diameter size of the vessel (with a resolution of ~2mm), as well as delineate the type of tissue surrounding the vessel. The system is low-cost, functions in real-time, and could be mounted on already existing surgical tools, such as Kittner dissectors or laparoscopic suction irrigation cannulae. Having been successfully validated ex vivo, this technology will next be tested in a live porcine study and eventually in clinical trials.

  11. Estimation of vessel diameter and blood flow dynamics from laser speckle images

    DEFF Research Database (Denmark)

    Postnov, Dmitry D.; Tuchin, Valery V.; Sosnovtseva, Olga

    2016-01-01

    Laser speckle imaging is a rapidly developing method to study changes of blood velocity in the vascular networks. However, to assess blood flow and vascular responses it is crucial to measure vessel diameter in addition to blood velocity dynamics. We suggest an algorithm that allows for dynamical...

  12. Computational Fluid Dynamics Analysis of Pulsatile Blood Flow Behavior in Modelled Stenosed Vessels with Different Severities

    Directory of Open Access Journals (Sweden)

    Mohsen Mehrabi

    2012-01-01

    Full Text Available This study focuses on the behavior of blood flow in the stenosed vessels. Blood is modelled as an incompressible non-Newtonian fluid which is based on the power law viscosity model. A numerical technique based on the finite difference method is developed to simulate the blood flow taking into account the transient periodic behaviour of the blood flow in cardiac cycles. Also, pulsatile blood flow in the stenosed vessel is based on the Womersley model, and fluid flow in the lumen region is governed by the continuity equation and the Navier-Stokes equations. In this study, the stenosis shape is cosine by using Tu and Devil model. Comparing the results obtained from three stenosed vessels with 30%, 50%, and 75% area severity, we find that higher percent-area severity of stenosis leads to higher extrapressure jumps and higher blood speeds around the stenosis site. Also, we observe that the size of the stenosis in stenosed vessels does influence the blood flow. A little change on the cross-sectional value makes vast change on the blood flow rate. This simulation helps the people working in the field of physiological fluid dynamics as well as the medical practitioners.

  13. An Experimental Study to Replace the Thoracic Descending Aorta for Pigs with a Self-Made Sutureless Blood Vessel

    Directory of Open Access Journals (Sweden)

    Fenglin Song

    2014-01-01

    Full Text Available To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex, respectively, in pigs. The aortic clamp time and the operative blood loss in the experimental group (using SMSBV were less than those in the control group (using Gore-Tex. The whole blood hematocrit, platelet count, plasma soluble P-selectin, plasma free hemoglobin, and interleukins 2, 6 at each time point were not different significantly between the two groups. Light microscopy and transmission electron microscopy examination showed there were layers of vascular smooth muscle cells and endothelial cells adhered in the inner wall of artificial blood vessel without any signs of thrombosis. Based on the result, we have drawn the conclusion that the application of SMSBV can significantly shorten the vascular anastomosis time, reduce operative blood loss, and show good blood and tissue compatibility.

  14. Continuum mathematical modelling of pathological growth of blood vessels

    Science.gov (United States)

    Stadnik, N. E.; Dats, E. P.

    2018-04-01

    The present study is devoted to the mathematical modelling of a human blood vessel pathological growth. The vessels are simulated as the thin-walled circular tube. The boundary value problem of the surface growth of an elastic thin-walled cylinder is solved. The analytical solution is obtained in terms of velocities of stress strain state parameters. The condition of thinness allows us to study finite displacements of cylinder surfaces by means of infinitesimal deformations. The stress-strain state characteristics, which depend on the mechanical parameters of the biological processes, are numerically computed and graphically analysed.

  15. Waves and fluid-solid interaction in stented blood vessels

    Science.gov (United States)

    Frecentese, S.; Argani, L. P.; Movchan, A. B.; Movchan, N. V.; Carta, G.; Wall, M. L.

    2018-01-01

    This paper focuses on the modelling of fluid-structure interaction and wave propagation problems in a stented artery. Reflection of waves in blood vessels is well documented in the literature, but it has always been linked to a strong variation in geometry, such as the branching of vessels. The aim of this work is to detect the possibility of wave reflection in a stented artery due to the repetitive pattern of the stents. The investigation of wave propagation and possible blockages under time-harmonic conditions is complemented with numerical simulations in the transient regime.

  16. Automatic segmentation of blood vessels from retinal fundus images ...

    Indian Academy of Sciences (India)

    The retinal blood vessels were segmented through color space conversion and color channel extraction, image pre-processing, Gabor filtering, image postprocessing, feature construction through application of principal component analysis, k-means clustering and first level classification using Naïve–Bayes classification ...

  17. Fluid Dynamics of Magnetic Nanoparticles in Simulated Blood Vessels

    Science.gov (United States)

    Blue, Lauren; Sewell, Mary Kathryn; Brazel, Christopher S.

    2008-11-01

    Magnetic nanoparticles (MNPs) can be used to locally target therapies and offer the benefit of using an AC magnetic field to combine hyperthermia treatment with the triggered release of therapeutic agents. Here, we investigate localization of MNPs in a simulated environment to understand the relationship between magnetic field intensity and bulk fluid dynamics to determine MNP retention in a simulated blood vessel. As MNPs travel through blood vessels, they can be slowed or trapped in a specific area by applying a magnetic field. Magnetic cobalt ferrite nanoparticles were synthesized and labeled with a fluorescent rhodamine tag to visualize patterns in a flow cell, as monitored by a fluorescence microscope. Particle retention was determined as a function of flow rate, concentration, and magnetic field strength. Understanding the relationship between magnetic field intensity, flow behavior and nanoparticle characteristics will aid in the development of therapeutic systems specifically targeted to diseased tissue.

  18. DLC coating of textile blood vessels using PLD

    Czech Academy of Sciences Publication Activity Database

    Kocourek, Tomáš; Jelínek, Miroslav; Vorlíček, Vladimír; Zemek, Josef; Janča, T.; Žížková, V.; Podlaha, J.; Popov, C.

    2008-01-01

    Roč. 93, č. 3 (2008), s. 627-632 ISSN 0947-8396 R&D Projects: GA MPO FI-IM2/068; GA ČR GA202/06/0216 Institutional research plan: CEZ:AV0Z10100522 Keywords : blood vessels * PLD * DLC * sp2 * sp3 Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.884, year: 2008

  19. Application of blood-pool agents in visualization of peripheral vessels

    International Nuclear Information System (INIS)

    Giovagnoni, A.; Catalano, C.

    2007-01-01

    Effective arterial imaging is essential in patients with peripheral arterial disease (PAD) in whom a revascularization procedure is planned. Digital subtraction angiography (DSA) has traditionally been regarded as the gold standard for imaging in peripheral arterial disease, but this technique is subject to certain limitations, such as the risks of adverse reactions associated with arterial catheterization and iodinated contrast agents. Contrast-enhanced magnetic resonance angiography is now recommended as an effective and useful imaging technique in peripheral arterial disease, since it offers high enhanced contrast between blood and stationary tissue and fast acquisition times. However, extracellular gadolinium contrast agents rapidly diffuse into the interstitial spaces, and thus are suitable only for first-pass imaging. This limitation can be overcome by the use of blood-pool (intravascular) contrast agents, such as gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany), which are retained within the blood vessels and hence facilitate both first-pass and steady-state imaging with high spatial resolution. Blood-pool agents, therefore, offer improved imaging, particularly of distal vessels, compared with extracellular contrast agents. Examples of first-pass and steady-state imaging with gadofosveset are presented. (orig.)

  20. Establishment of an animal model of mice with radiation- injured soft tissue blood vessels

    International Nuclear Information System (INIS)

    Wang Daiyou; Yu Dahai; Wu Jiaxiao; Wei Shanliang; Wen Yuming

    2004-01-01

    Objective: The aim of this study was to establish an animal model of mice with radiation-injured soft tissue blood vessels. Methods: Forty male mice were irradiated with 30 Gy on the right leg. After the irradiation was finished each of the 40 male mice was tested with angiography, and its muscle tissues on the bilateral legs were examined with vessel staining assay and electron microscopy. Results: The results showed that the number of vessels on the right leg was less than that on the left leg, the microvessel density, average diameter and average sectional area of the right leg were all lower than those of the left, and the configuration and ultra-structure of vessels were also different between both sides of legs. Conclusion: In the study authors successfully established an animal model of mice with radiation-injured soft tissue blood vessels

  1. Mouse lung contains endothelial progenitors with high capacity to form blood and lymphatic vessels

    Directory of Open Access Journals (Sweden)

    Barleon Bernhard

    2010-07-01

    Full Text Available Abstract Background Postnatal endothelial progenitor cells (EPCs have been successfully isolated from whole bone marrow, blood and the walls of conduit vessels. They can, therefore, be classified into circulating and resident progenitor cells. The differentiation capacity of resident lung endothelial progenitor cells from mouse has not been evaluated. Results In an attempt to isolate differentiated mature endothelial cells from mouse lung we found that the lung contains EPCs with a high vasculogenic capacity and capability of de novo vasculogenesis for blood and lymph vessels. Mouse lung microvascular endothelial cells (MLMVECs were isolated by selection of CD31+ cells. Whereas the majority of the CD31+ cells did not divide, some scattered cells started to proliferate giving rise to large colonies (> 3000 cells/colony. These highly dividing cells possess the capacity to integrate into various types of vessels including blood and lymph vessels unveiling the existence of local microvascular endothelial progenitor cells (LMEPCs in adult mouse lung. EPCs could be amplified > passage 30 and still expressed panendothelial markers as well as the progenitor cell antigens, but not antigens for immune cells and hematopoietic stem cells. A high percentage of these cells are also positive for Lyve1, Prox1, podoplanin and VEGFR-3 indicating that a considerabe fraction of the cells are committed to develop lymphatic endothelium. Clonogenic highly proliferating cells from limiting dilution assays were also bipotent. Combined in vitro and in vivo spheroid and matrigel assays revealed that these EPCs exhibit vasculogenic capacity by forming functional blood and lymph vessels. Conclusion The lung contains large numbers of EPCs that display commitment for both types of vessels, suggesting that lung blood and lymphatic endothelial cells are derived from a single progenitor cell.

  2. Ultrastructure of Pericystic or Intracystic Blood Vessels in Epidermoid Cysts-A Transmission Electron Microscopy Study: Laboratory Investigation.

    Science.gov (United States)

    Ren, Xiao-Hui; Ma, Jun; Zeng, Chun; Sun, Yi-Lin; Lin, Song

    2017-07-01

    Recently, we reported a tendency toward spontaneous hemorrhage in both the preoperative and postoperative periods in patients with intracranial epidermoid cyst (EC). According to our experience, this tendency for spontaneous hemorrhage was partly caused by the pathologic blood vessels adjacent to the EC. This study was designed to testify this hypothesis. Twenty-three removable pericystic or intracystic blood vessels from 17 patients with EC were collected during surgery and were then examined by transmission electron microscopy. The microvascular structure in gliomas was chosen as the control. Under electron microscopy, variant pathologic changes of vessels were found in all patients with EC. In the tunicae intima, we found vacuolization, apoptosis, necrosis, and intralumenal protrusion of endothelial cells, as well as swollen basement and highly flexed and discontinued elastic plate. In the tunicae media, vacuolization and swollen mitochondria were found in muscular cells. In the tunicae adventitia, extravascular erythrocytes, edema or apoptosis of pericytes, collagen predominance, and inflammatory cell infiltration and destruction were found. Neuron denature and necrosis were found in the peripheral brain tissue. In the microvascular structure of 5 glioma specimens, we found enlargement and hyperplasia of endothelial cells, swollen basement membrane, swollen pericytes, and astrocytic hyperplasia and neuron denature in adjacent brain tissues. Our findings provide strong evidence for the hypothesis that intracystic or pericystic vascular degeneration or destruction accounts for the spontaneous hemorrhage tendency before and after surgical resection of ECs. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. The efficiency of laser radiation absorption by hemoglobin and oxyhemoglobin in the skin blood vessels

    International Nuclear Information System (INIS)

    Asimov, M.; Asimov, R.; Gisbrecht, A.

    1999-01-01

    The results of the investigation of the efficiency of light absorption by oxyhemoglobin (HbO 2 ) and deoxyhemoglobin (Hb) in cutaneous blood vessels in dependence on the radiation wavelength and the optical properties of the tissue is presented. Using the Kubelka - Munk optical model of the tissue the spectral dependence of the efficiency of laser interaction both on HbO 2 and Hb of blood vessels at different depths of the tissue layer are calculated. The obtained results show that for blood vessels located in tissue up to a depth of 2500 μm the efficiency of laser radiation absorption follows the shape of the Q -absorption bands of HbO 2 and Hb

  4. Simulative study on dose distribution of 103Pd stent in blood-vessel

    International Nuclear Information System (INIS)

    Yuan Shuyu; Dai Guangfu; Xu Zhiyong; Sun Fuyin; Xu Shuhe; Ma Fengwu

    2003-01-01

    Objective: To evaluate the dose distribution of 103 Pd stent in the blood-vessel. Methods: Simulative study on dose distribution of endovascular 103 Pd stent was conducted with thermoluminescence dosimeter. The vessel wall was substituted by muscle equivalent material in this simulative study. Results: When radioactivity of the study 103 Pd stent was 9.8 MBq the absorbed dose from the stent surface by muscle equivalent material was 9.8 Gy at 17 d (the half-life period of 103 Pd). The radioactivity of 103 Pd stent surface rapidly attenuated over the radial distance. 80% of the radioactivity at the area that was radially 0.4 mm apart from the stent surface was absorbed by the simulative blood-vessel wall. Conclusion: Endovascular 103 Pd stent does not exert significant injury on the surrounding organs or tissues

  5. 3-D segmentation of retinal blood vessels in spectral-domain OCT volumes of the optic nerve head

    Science.gov (United States)

    Lee, Kyungmoo; Abràmoff, Michael D.; Niemeijer, Meindert; Garvin, Mona K.; Sonka, Milan

    2010-03-01

    Segmentation of retinal blood vessels can provide important information for detecting and tracking retinal vascular diseases including diabetic retinopathy, arterial hypertension, arteriosclerosis and retinopathy of prematurity (ROP). Many studies on 2-D segmentation of retinal blood vessels from a variety of medical images have been performed. However, 3-D segmentation of retinal blood vessels from spectral-domain optical coherence tomography (OCT) volumes, which is capable of providing geometrically accurate vessel models, to the best of our knowledge, has not been previously studied. The purpose of this study is to develop and evaluate a method that can automatically detect 3-D retinal blood vessels from spectral-domain OCT scans centered on the optic nerve head (ONH). The proposed method utilized a fast multiscale 3-D graph search to segment retinal surfaces as well as a triangular mesh-based 3-D graph search to detect retinal blood vessels. An experiment on 30 ONH-centered OCT scans (15 right eye scans and 15 left eye scans) from 15 subjects was performed, and the mean unsigned error in 3-D of the computer segmentations compared with the independent standard obtained from a retinal specialist was 3.4 +/- 2.5 voxels (0.10 +/- 0.07 mm).

  6. Neutrophil-Mediated Delivery of Therapeutic Nanoparticles across Blood Vessel Barrier for Treatment of Inflammation and Infection.

    Science.gov (United States)

    Chu, Dafeng; Gao, Jin; Wang, Zhenjia

    2015-12-22

    Endothelial cells form a monolayer in lumen of blood vessels presenting a great barrier for delivery of therapeutic nanoparticles (NPs) into extravascular tissues where most diseases occur, such as inflammation disorders and infection. Here, we report a strategy for delivering therapeutic NPs across this blood vessel barrier by nanoparticle in situ hitchhiking activated neutrophils. Using intravital microscopy of TNF-α-induced inflammation of mouse cremaster venules and a mouse model of acute lung inflammation, we demonstrated that intravenously (iv) infused NPs made from denatured bovine serum albumin (BSA) were specifically internalized by activated neutrophils, and subsequently, the neutrophils containing NPs migrated across blood vessels into inflammatory tissues. When neutrophils were depleted using anti-Gr-1 in a mouse, the transport of albumin NPs across blood vessel walls was robustly abolished. Furthermore, it was found that albumin nanoparticle internalization did not affect neutrophil mobility and functions. Administration of drug-loaded albumin NPs markedly mitigated the lung inflammation induced by LPS (lipopolysaccharide) or infection by Pseudomonas aeruginosa. These results demonstrate the use of an albumin nanoparticle platform for in situ targeting of activated neutrophils for delivery of therapeutics across the blood vessel barriers into diseased sites. This study demonstrates our ability to hijack neutrophils to deliver nanoparticles to targeted diseased sites.

  7. "Sausage-string" appearance of arteries and arterioles can be caused by an instability of the blood vessel wall

    DEFF Research Database (Denmark)

    Jacobsen, Jens Christian Brings; Beierholm, Ulrik; Mikkelsen, Rene

    2002-01-01

    Vascular damage induced by acute hypertension is preceded by a peculiar pattern where blood vessels show alternating regions of constrictions and dilations ("sausages on a string"). The pattern occurs in the smaller blood vessels, and it plays a central role in causing the vascular damage. A rela...... phenomenon. Experimental data suggest that the structural changes induced by the instability may cause secondary damage to the wall of small arteries and arterioles in the form of endothelial hyperpermeability followed by local fibrinoid necrosis of the vascular wall.......Vascular damage induced by acute hypertension is preceded by a peculiar pattern where blood vessels show alternating regions of constrictions and dilations ("sausages on a string"). The pattern occurs in the smaller blood vessels, and it plays a central role in causing the vascular damage....... A related vascular pattern has been observed in larger vessels from several organs during angiography. In the larger vessels the occurrence of the pattern does not appear to be related to acute hypertension. A unifying feature between the phenomenon in large and small vessels seems to be an increase...

  8. MACROMICROSCOPIC AND ULTRAMICROSCOPIC CHARACTERISTICS OF THE HART AND ITS BLOOD VESSELS IN MICE EHRLICHIOSIS INFECTION

    Directory of Open Access Journals (Sweden)

    Pokhil S. I.

    2013-12-01

    Full Text Available The macromicroscopic, ultramicroscopic studying change’s in the hart and its blood vessels in unlinear immunocomprometive laboratory male and female mice with the experimental ehrlichiosis is presented in this article. The cardiac destructive and degenerative changes,cardiomyopathy, cardiosclerosis had been established inexperimental animal group’s. The blood vessels endothelial lieyr disorganization, stasis, thrombosis has been noted.

  9. An experimental system for the study of ultrasound exposure of isolated blood vessels

    NARCIS (Netherlands)

    Tokarczyk, Anna; Rivens, Ian; van Bavel, E.; Symonds-Tayler, Richard; ter Haar, Gail

    2013-01-01

    An experimental system designed for the study of the effects of diagnostic or therapeutic ultrasound exposure on isolated blood vessels in the presence or absence of intraluminal contrast agent is described. The system comprised several components. A microscope was used to monitor vessel size (and

  10. Theoretical evaluations of magnetic nanoparticle-enhanced heating on tumor embedded with large blood vessels during hyperthermia

    International Nuclear Information System (INIS)

    Wang, Q.; Deng, Z. S.; Liu, J.

    2012-01-01

    The large blood vessels surrounding the tumor would significantly result in heat sink, and thus seriously limit the thermal ablative area during tumor hyperthermia. Magnetic nanoparticle (MNP) was recently identified as an important heating enhancer to improve the treatment efficiency. It will not only help to absorb more energy under the irradiation of external magnetic field, but also can block the blood flow and subsequently weaken the heat sink effect of large vessels. In this study, these two critical factors, reserved to be undisclosed before in theory, were comprehensively investigated through three-dimensional numerical simulation. The results suggested that concerning the contribution to temperature increase in the tissues surrounding large vessel, the factor of blood flow blocking is more effective than that of energy absorption. Therefore, selective loading of MNPs to the target sites is expected to serve as a promising method to perform successful hyperthermia treatment for tumor tissues embedded with large blood vessels.

  11. Theoretical evaluations of magnetic nanoparticle-enhanced heating on tumor embedded with large blood vessels during hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q. [Tsinghua University, Department of Biomedical Engineering, School of Medicine (China); Deng, Z. S. [Chinese Academy of Sciences, Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry (China); Liu, J., E-mail: jliubme@tsinghua.edu.cn [Tsinghua University, Department of Biomedical Engineering, School of Medicine (China)

    2012-07-15

    The large blood vessels surrounding the tumor would significantly result in heat sink, and thus seriously limit the thermal ablative area during tumor hyperthermia. Magnetic nanoparticle (MNP) was recently identified as an important heating enhancer to improve the treatment efficiency. It will not only help to absorb more energy under the irradiation of external magnetic field, but also can block the blood flow and subsequently weaken the heat sink effect of large vessels. In this study, these two critical factors, reserved to be undisclosed before in theory, were comprehensively investigated through three-dimensional numerical simulation. The results suggested that concerning the contribution to temperature increase in the tissues surrounding large vessel, the factor of blood flow blocking is more effective than that of energy absorption. Therefore, selective loading of MNPs to the target sites is expected to serve as a promising method to perform successful hyperthermia treatment for tumor tissues embedded with large blood vessels.

  12. Modification method to reduce the impact of blood vessel on noncontact discrimination of human blood based on ;M+N; theory

    Science.gov (United States)

    Zhang, Linna; Ding, Hongyan; Lin, Ling; Wang, Yimin; Guo, Xin

    2018-01-01

    Noncontact discriminating human blood is significantly crucial for import-export ports and inspection and quarantine departments. We had already demonstrated that visible diffuse reflectance spectroscopy combining PLS-DA method can successfully realize noncontact human blood discrimination. However, the circulated blood vessels may be produced with different materials. The use of various kinds of blood tubes may have a negative effect on the discrimination, based on ;M+N; theory (Li et al., 2016). In this research, we explored the impact of different material of blood vessels, such as glass tube and plastic tube, on the prediction ability of the discrimination model. Furthermore, we searched for the modification method to reduce the influence from the blood tubes. Our work indicated that generalized diffuse reflectance method can greatly improve the discrimination accuracy. This research can greatly facilitate the application of noncontact discrimination method based on visible and near-infrared diffuse reflectance spectroscopy.

  13. Segmentation of retinal blood vessels using artificial neural networks for early detection of diabetic retinopathy

    Science.gov (United States)

    Mann, Kulwinder S.; Kaur, Sukhpreet

    2017-06-01

    There are various eye diseases in the patients suffering from the diabetes which includes Diabetic Retinopathy, Glaucoma, Hypertension etc. These all are the most common sight threatening eye diseases due to the changes in the blood vessel structure. The proposed method using supervised methods concluded that the segmentation of the retinal blood vessels can be performed accurately using neural networks training. It uses features which include Gray level features; Moment Invariant based features, Gabor filtering, Intensity feature, Vesselness feature for feature vector computation. Then the feature vector is calculated using only the prominent features.

  14. A three-temperature model of selective photothermolysis for laser treatment of port wine stain containing large malformed blood vessels

    International Nuclear Information System (INIS)

    Li, D.; Wang, G.X.; He, Y.L.; Wu, W.J.; Chen, B.

    2014-01-01

    As congenital vascular malformations, port wine stain (PWS) is composed of ectatic venular capillary blood vessels buried within healthy dermis. In clinic, pulsed dye laser (PDL) in visible band (e.g. 585 nm) together with cryogen spray cooling (CSC) have become the golden standard for treatment of PWS. However, due to the limited energy deposition of the PDL in blood, large blood vessels are likely to survive from the laser irradiation. As a result, complete clearance of the lesions is rarely achieved. Assuming the local thermal non-equilibrium in skin tissue during the laser surgery, a three-temperature model is proposed to treat the PWS tissue as a porous media composed of a non-absorbing dermal matrix buried with the blood as well as the large malformed blood vessels. Three energy equations are constructed and solved coupling for the temperature of the blood in average-sized PWS vessels, non-absorbing dermal tissues and large malformed blood vessels, respectively. Subsequently, the thermal responses of human skin to visible (585 nm) and near-infrared (1064 nm) laser irradiations with various pulse durations in conjunction with cryogen spray cooling are investigated by the new model, and Arrhenius integral is used to analyze the thermal damage. The simulations show that the short pulse duration of 1.5 ms results in a higher selective heating of blood over epidermis, which will lead to a desired clinic outcome than the longer pulse duration. Due to a much deeper light penetration depth, laser irradiation with 1064 nm in wavelength is superior to that with 585 nm in treating patients with cutaneous hyper-vascular malformation. Complete coagulations are predicted in large-sized and deeply extending blood vessels by 1064 nm laser. - Highlights: •A three-temperature model is proposed for the laser treatment of port wine stain (PWS). •Average sized and large malformed blood vessels in porous medium (tissue) are considered. •Thermal responses of PWS to

  15. Removing vessels from the water for biofouling treatment has the potential to introduce mobile non-indigenous marine species.

    Science.gov (United States)

    Coutts, Ashley D M; Valentine, Joseph P; Edgar, Graham J; Davey, Adam; Burgess-Wilson, Bella

    2010-09-01

    Vessels found contaminated with biofouling non-indigenous marine species are predominantly removed from the water and treated in vessel maintenance facilities (i.e., slipways, travel lifts and dry-docks). Using pre-fouled settlement plates to simulate a vessel's removal from the water for treatment, we demonstrate that a range of mobile organisms (including non-indigenous marine species) may be lost to the marine environment as a consequence of this process. We also determined that different levels of biofouling (primary, secondary and tertiary) and emersion durations (0.5, 5 and 15 min) affected the abundance and composition of mobile taxa lost to the marine environment. Primary biofouling plates lost 3.2% of total animals, secondary plates lost 19.8% and tertiary plates lost 8.2%, while hanging duration had only minor effects. The results suggest that removing vessels contaminated with biofouling non-indigenous marine species from the water for treatment may not be as biosecure as is currently recognised. Copyright 2010 Elsevier Ltd. All rights reserved.

  16. Effects of blood-activating and stasis-removing drugs combined with VEGF gene transfer on angiogenesis in ischemic necrosis of the femoral head.

    Science.gov (United States)

    Li, Jun-Hui; Wu, Ya-Ling; Ye, Jian-Hong; Ning, Ya-Gong; Yu, Hai-Ying; Peng, Zhong-Jie; Luan, Xiao-Wen

    2009-09-01

    To observe the promoting effects of blood-activating and stasis-removing Chinese drugs combined with vascular endothelial growth factor (VEGF) gene transfer on angiogenesis in ischemic necrosis of the femoral head. Forty Japanese giant-ear rabbits were randomly divided into a control group, a model group, a Chinese drug group, a gene group, and a combined group. After 8 weeks of treatment, the rate of VEGF positive cell expression in the synovium of the femoral head was measured using the immunohistochemical method, and the number of blood vessels in the femoral head was measured by digital subtraction angiography. The rate of VEGF positive cell expression in the model group was significantly lower than that in the Chinese drug group (P 0.05). Either the blood-activating and stasis-removing Chinese drugs or VEGF gene transfer can promote the angiogenesis and building of collateral circulation for femoral head ischemic necrosis, and the combined therapy with Chinese drugs or VEGF gene transfer may show a better therapeutic effect. The present study provides an experimental basis for clinical application of the combined therapy with the blood-activating and stasis-removing Chinese drugs and VEGF gene transfer.

  17. Retinal blood vessel extraction using tunable bandpass filter and fuzzy conditional entropy.

    Science.gov (United States)

    Sil Kar, Sudeshna; Maity, Santi P

    2016-09-01

    Extraction of blood vessels on retinal images plays a significant role for screening of different opthalmologic diseases. However, accurate extraction of the entire and individual type of vessel silhouette from the noisy images with poorly illuminated background is a complicated task. To this aim, an integrated system design platform is suggested in this work for vessel extraction using a sequential bandpass filter followed by fuzzy conditional entropy maximization on matched filter response. At first noise is eliminated from the image under consideration through curvelet based denoising. To include the fine details and the relatively less thick vessel structures, the image is passed through a bank of sequential bandpass filter structure optimized for contrast enhancement. Fuzzy conditional entropy on matched filter response is then maximized to find the set of multiple optimal thresholds to extract the different types of vessel silhouettes from the background. Differential Evolution algorithm is used to determine the optimal gain in bandpass filter and the combination of the fuzzy parameters. Using the multiple thresholds, retinal image is classified as the thick, the medium and the thin vessels including neovascularization. Performance evaluated on different publicly available retinal image databases shows that the proposed method is very efficient in identifying the diverse types of vessels. Proposed method is also efficient in extracting the abnormal and the thin blood vessels in pathological retinal images. The average values of true positive rate, false positive rate and accuracy offered by the method is 76.32%, 1.99% and 96.28%, respectively for the DRIVE database and 72.82%, 2.6% and 96.16%, respectively for the STARE database. Simulation results demonstrate that the proposed method outperforms the existing methods in detecting the various types of vessels and the neovascularization structures. The combination of curvelet transform and tunable bandpass

  18. Blood vessel growth blocker may treat AIDS-related Kaposi’s sarcoma

    Science.gov (United States)

    Patients with an AIDS-associated cancer, Kaposi's sarcoma (KS), showed improvement after receiving the combination of bevacizumab, a cancer drug that blocks the growth of new blood vessels, and highly active antiretroviral therapy (HAART).

  19. Fine structural alterations of the blood vessels in the delayed radionecrosis of the human brain and its pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, H [Nagasaki Univ. (Japan). School of Medicine

    1981-05-01

    The blood vessels in the delayed radionecrosis of the human brain were studied under light and electron microscopes. Microscopically, the blood vessels demonstrated characteristic findings such as fibrinoid necrosis, hyalinized thickened vessels, perivascular fibrosis and thrombosed vessels. Electron microscopy revealed the formation of fenestrae, separation of endothelial cells, increased pinocytotic vesicles as well as the initial thrombus formation. Our results strongly verified that vascular alterations are primary in the pathogenesis of radionecrosis whereas the parenchymal changes are secondary.

  20. Molecular imaging of tumor blood vessels in prostate cancer.

    Science.gov (United States)

    Tilki, Derya; Seitz, Michael; Singer, Bernhard B; Irmak, Ster; Stief, Christian G; Reich, Oliver; Ergün, Süleyman

    2009-05-01

    In the past three decades many efforts have been undertaken to understand the mechanisms of tumor angiogenesis. The introduction of anti-angiogenic drugs in tumor therapy during the last few years necessitates the establishment of new techniques enabling molecular imaging of tumor vascular remodelling. The determination of tumor size as commonly used is not appropriate since the extended necrosis under anti-angiogenic therapy does not necessarily result in the reduction of tumor diameter. The basis for the molecular imaging of tumor blood vessels is the remodelling of the tumor vessels under anti-angiogenic therapy which obviously occurs at an early stage and seems to be a convincing parameter. Beside the enormous progress in this field during the last few years the resolution is still not high enough to evaluate the remodelling of the micro tumor vessels. New imaging approaches combining specific molecular markers for tumor vessels with the different imaging techniques are needed to overcome this issue as exemplarily discussed for prostate cancer in this review. Molecular contrast agents targeting the vasculature will allow clinicians the visualization of vascular remodelling processes taking place under anti-angiogenic therapy and improve tumor diagnosis and follow-up.

  1. Aminopeptidase A is a functional target in angiogenic blood vessels.

    NARCIS (Netherlands)

    Marchio, S.; Lahdenranta, J.; Schlingemann, R.O.; Valdembri, D.; Wesseling, P.; Arap, M.A.; Hajitou, A.; Ozawa, M.G.; Trepel, M.; Giordano, R.J.; Nanus, D.M.; Dijkman, H.B.P.M.; Oosterwijk, E.; Sidman, R.L.; Cooper, M.D.; Bussolino, F.; Pasqualini, R.; Arap, W.

    2004-01-01

    We show that a membrane-associated protease, aminopeptidase A (APA), is upregulated and enzymatically active in blood vessels of human tumors. To gain mechanistic insight, we evaluated angiogenesis in APA null mice. We found that, although these mice develop normally, they fail to mount the expected

  2. Aminopeptidase A is a functional target in angiogenic blood vessels

    NARCIS (Netherlands)

    Marchiò, Serena; Lahdenranta, Johanna; Schlingemann, Reinier O.; Valdembri, Donatella; Wesseling, Pieter; Arap, Marco A.; Hajitou, Amin; Ozawa, Michael G.; Trepel, Martin; Giordano, Ricardo J.; Nanus, David M.; Dijkman, Henri B. P. M.; Oosterwijk, Egbert; Sidman, Richard L.; Cooper, Max D.; Bussolino, Federico; Pasqualini, Renata; Arap, Wadih

    2004-01-01

    We show that a membrane-associated protease, aminopeptidase A (APA), is upregulated and enzymatically active in blood vessels of human tumors. To gain mechanistic insight, we evaluated angiogenesis in APA null mice. We found that, although these mice develop normally, they fail to mount the expected

  3. [Applications of platelets in studies on traditional Chinese medicines promoting blood circulation to remove blood stasis].

    Science.gov (United States)

    Wang, Feng-Qin; Chen, Cen; Xia, Zhi-Ning; Yang, Feng-Qing

    2014-08-01

    Thrombotic diseases in different forms become a great threat to human health. Such anti-platelet aggregation drugs as aspirin and clopidogrel are common drugs in clinic. However, along with the appearance of resistance and side effects of western anti-platelet aggregation drugs, anti-platelet aggregation traditional Chinese medicines promoting blood circulation to remove blood stasis have gradually become an important study orientation. Platelet is one of major participant in thrombosis, and plays an important role as a bioactive material in studies on traditional Chinese medicines promoting blood circulation to remove blood stasis, mainly involving two aspects--the evaluation for the anti-platelet aggregation activity of traditional Chinese medicines and the screening of their active components. This paper summarized the applications of platelets in studies on traditional Chinese medicines promoting blood circulation to remove blood stasis, so as to provide basis for further studies.

  4. Dependence of light scattering profile in tissue on blood vessel diameter and distribution: a computer simulation study.

    Science.gov (United States)

    Duadi, Hamootal; Fixler, Dror; Popovtzer, Rachela

    2013-11-01

    Most methods for measuring light-tissue interactions focus on the volume reflectance while very few measure the transmission. We investigate both diffusion reflection and diffuse transmission at all exit angles to receive the full scattering profile. We also investigate the influence of blood vessel diameter on the scattering profile of a circular tissue. The photon propagation path at a wavelength of 850 nm is calculated from the absorption and scattering constants via Monte Carlo simulation. Several simulations are performed where a different vessel diameter and location were chosen but the blood volume was kept constant. The fraction of photons exiting the tissue at several central angles is presented for each vessel diameter. The main result is that there is a central angle that below which the photon transmission decreased for lower vessel diameters while above this angle the opposite occurred. We find this central angle to be 135 deg for a two-dimensional 10-mm diameter circular tissue cross-section containing blood vessels. These findings can be useful for monitoring blood perfusion and oxygen delivery in the ear lobe and pinched tissues. © 2013 Society of Photo-Optical Instrumentation Engineers (SPIE)

  5. Ultrasonographic Examination of Some Vessels in Dogs and the Characteristics of Blood Flow in These Vessels

    Directory of Open Access Journals (Sweden)

    Figurová M.

    2017-12-01

    Full Text Available The examination by Doppler ultrasonography provides haemodynamic information about blood flow velocity in a respective vessel. It specifies high- and lowresistance flow patterns. The aim of our study was to record the flow in a. carotis communis, a. femoralis and aa. renales in 16 adult clinically healthy dogs of small and medium size; characterize the types of vessels and also determine the pulsatility index (PI and the resistive index (RI of these vessels. The a. femoralis is a high-resistance vessel with a pronounced three-peak waveform. The aa. renales gives a typical picture of a low-resistance flow pattern. The characteristics of a. carotis communis involves different images of its branches a. carotis interna and a. carotis externa. In the investigated groups we observed a medium degree of pulsatility (atypical highresistance flow pattern with an absence of reverse flow. The mean measured values of indices for a. carotis communis were: left side PI 1.824 and RI 0.742; right side PI 1.891 and RI 0.746, and for aa. renales: PI 1.366 ± 0.04 and RI 0.684 ± 0.05.

  6. Vascular patterns in the heads of crocodilians: blood vessels and sites of thermal exchange.

    Science.gov (United States)

    Porter, William Ruger; Sedlmayr, Jayc C; Witmer, Lawrence M

    2016-12-01

    Extant crocodilians are a highly apomorphic archosaur clade that is ectothermic, yet often achieve large body sizes that can be subject to higher heat loads. Therefore, the anatomical and physiological roles that blood vessels play in crocodilian thermoregulation need further investigation to better understand how crocodilians establish and maintain cephalic temperatures and regulate neurosensory tissue temperatures during basking and normal activities. The cephalic vascular anatomy of extant crocodilians, particularly American alligator (Alligator mississippiensis) was investigated using a differential-contrast, dual-vascular injection technique and high resolution X-ray micro-computed tomography (μCT). Blood vessels were digitally isolated to create representations of vascular pathways. The specimens were then dissected to confirm CT results. Sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in evaporative cooling and cephalic thermoregulation in other diapsids. Blood vessels to and from sites of thermal exchange were studied to detect conserved vascular patterns and to assess their ability to deliver cooled blood to neurosensory tissues. Within the orbital region, both the arteries and veins demonstrated consistent branching patterns, with the supraorbital, infraorbital, and ophthalmotemporal vessels supplying and draining the orbit. The venous drainage of the orbital region showed connections to the dural sinuses via the orbital veins and cavernous sinus. The palatal region demonstrated a vast plexus that comprised both arteries and veins. The most direct route of venous drainage of the palatal plexus was through the palatomaxillary veins, essentially bypassing neurosensory tissues. Anastomotic connections with the nasal region, however, may provide an alternative route for palatal venous blood to reach neurosensory tissues. The nasal region in crocodilians is probably the most

  7. Hybrid PIV-PTV technique for measuring blood flow in rat mesenteric vessels.

    Science.gov (United States)

    Ha, Hojin; Nam, Kweon-Ho; Lee, Sang Joon

    2012-11-01

    The micro-particle tracking velocimetry (μ-PTV) technique is used to obtain the velocity fields of blood flow in the microvasculature under in vivo conditions because it can provide the blood velocity distribution in microvessels with high spatial resolution. The in vivo μ-PTV technique usually requires a few to tens of seconds to obtain a whole velocity profile across the vessel diameter because of the limited number density of tracer particles under in vivo conditions. Thus, the μ-PTV technique alone is limited in measuring unsteady blood flows that fluctuate irregularly due to the heart beating and muscle movement in surrounding tissues. In this study, a new hybrid PIV-PTV technique was established by combining PTV and particle image velocimetry (PIV) techniques to resolve the drawbacks of the μ-PTV method in measuring blood flow in microvessels under in vivo conditions. Images of red blood cells (RBCs) and fluorescent particles in rat mesenteric vessels were obtained simultaneously. Temporal variations of the centerline blood velocity were monitored using a fast Fourier transform-based cross-correlation PIV method. The fluorescence particle images were analyzed using the μ-PTV technique to extract the spatial distribution of the velocity vectors. Data from the μ-PTV and PIV methods were combined to obtain a better estimate of the velocity profile in actual blood flow. This technique will be useful in investigating hemodynamics in microcirculation by measuring unsteady irregular blood flows more accurately. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Feasibility evaluation of 3D photoacoustic imaging of blood vessel structure using multiple wavelengths with a handheld probe

    Science.gov (United States)

    Uchimoto, Yo; Namita, Takeshi; Kondo, Kengo; Yamakawa, Makoto; Shiina, Tsuyoshi

    2018-02-01

    Photoacoustic imaging is anticipated for use in portraying blood vessel structures (e.g. neovascularization in inflamed regions). To reduce invasiveness and enhance ease handling, we developed a handheld photoacoustic imaging system using multiple wavelengths. The usefulness of the proposed system was investigated in phantom experiments and in vivo measurements. A silicon tube was embedded into chicken breast meat to simulate the blood vessel. The tube was filled with ovine blood. Then laser light was guided to the phantom surface by an optical fiber bundle close to the linear ultrasound probe. Photoacoustic images were obtained at 750-950 nm wavelengths. Strong photoacoustic signals from the boundary between blood and silicon tube are observed in these images. The shape of photoacoustic spectrum at the boundary resembles that of the HbO2 absorption spectrum at 750-920 nm. In photoacoustic images, similarity between photoacoustic spectrum and HbO2 absorption spectrum was evaluated by calculating the normalized correlation coefficient. Results show high correlation in regions of strong photoacoustic signals in photoacoustic images. These analyses demonstrate the feasibility of portraying blood vessel structures under practical conditions. To evaluate the feasibility of three-dimensional vascular imaging, in vivo experiments were conducted using three wavelengths. A right hand and ultrasound probe were set in degassed water. By scanning a probe, cross-sectional ultrasound and photoacoustic images were obtained at each location. Then, all ultrasound or photoacoustic images were piled up respectively. Then three-dimensional images were constructed. Resultant images portrayed blood vessel-like structures three-dimensionally. Furthermore, to distinguish blood vessels from other tissues (e.g. skin), distinguishing images of them were constructed by comparing photoacoustic signal intensity among three wavelengths. The resultant image portrayed blood vessels as

  9. In-vessel inspection before head removal: TMI II: Phase I. (Conceptual development)

    International Nuclear Information System (INIS)

    Calloway, N.E.; Greenlee, D.W.; Lawrence, G.R.; Paglia, A.L.; Piatt, T.D.; Tucker, B.A.

    1981-08-01

    The objective of the task is to provide for an internal inspection of the reactor vessel and the fuel assemblies prior to reactor vessel head removal. Because the degree of damage to equipment and fuel in the TMI-II reactor is not precisely known, it is important that as much information as possible be obtained on present conditions inside the reactor. This information will serve to benchmark the various analyses already completed or underway and will also guide the development of programs to obtain more information on the TMI-II core damage. In addition, the early look will provide data for planning the reactor disassembly program

  10. Analysis of trends and prospects regarding stents for human blood vessels.

    Science.gov (United States)

    Lee, Jeong Hee; Kim, Eung Do; Jun, Eun Jung; Yoo, Hyoung Sun; Lee, Joon Woo

    2018-01-01

    The purpose of this paper is to provide technology trends and information regarding market and prospects in stents used for human blood vessels in Korea and the world.A stent is a medical device in the form of a cylindrical metal net used to normalize flow when blood or other bodily fluids such as biliary fluids are obstructed in blood vessels, gastrointestinal tracts, etc. by inserting the stent into a narrowed or clogged area. Stents are classified into vascular and non-vascular stents. The coronary artery stent is avascular stent that is used for coronary atherosclerosis.The demand is increasing for stents to treat diseases such as those affecting the heart and blood vessels of elderly and middle-aged patients. Due to the current shift in the demographic structure caused by an aging society, the prospect for stents seems to be very bright.The use of a stent designed to prevent acute vascular occlusion and restenosis, which is a side effect of conventional balloon angioplasty, has rapidly become popular because it can prevent acute complications and improve clinical outcomes. Since the initial release of this stent, there have been significant developments in its design, the most notable of which has been the introduction of drug-eluting stents (DES). Bioresorbable scaffolds (BRS) have the potential to introduce a paradigm shift in interventional cardiology, a true anatomical and functional "vascular restoration" instead of an artificial stiff tube encased by a persistent metallic foreign body. Data for this research were gathered from primary and secondary sources as well as the databases of the Korea Institute of Science Technology Information (KISTI) located in Seoul, Korea like KISTI Market Report. The sources used for primary research included the databases available from the Korea Institute of Science Technology Information, past industry research services/studies, economic and demographic data, and trade and industry journals. Secondary research was used

  11. An experimental system for the study of ultrasound exposure of isolated blood vessels

    International Nuclear Information System (INIS)

    Tokarczyk, Anna; Rivens, Ian; Symonds-Tayler, Richard; Ter Haar, Gail; Van Bavel, E

    2013-01-01

    An experimental system designed for the study of the effects of diagnostic or therapeutic ultrasound exposure on isolated blood vessels in the presence or absence of intraluminal contrast agent is described. The system comprised several components. A microscope was used to monitor vessel size (and thus vessel functionality), and potential leakage of intraluminal 70 kDa FITC-dextran fluorescence marker. A vessel chamber allowed the mounting of an isolated vessel whilst maintaining its viability, with pressure regulation for the control of intraluminal pressure and induction of flow for the infusion of contrast microbubbles. A fibre-optic hydrophone sensor mounted on the vessel chamber using a micromanipulator allowed pre-exposure targeting of the vessel to within 150 µm, and monitoring of acoustic cavitation emissions during exposures. Acoustic cavitation was also detected using changes in the ultrasound drive voltage and by detection of audible emissions using a submerged microphone. The suitability of this system for studying effects in the isolated vessel model has been demonstrated using a pilot study of 6 sham exposed and 18 high intensity focused ultrasound exposed vessels, with or without intraluminal contrast agent (SonoVue) within the vessels. (paper)

  12. Angiogenesis and blood vessel stability in inflammatory arthritis.

    LENUS (Irish Health Repository)

    Kennedy, Aisling

    2012-02-01

    OBJECTIVE: To assess blood vessel stability in inflammatory synovial tissue (ST) and to examine neural cell adhesion molecule (NCAM), oxidative DNA damage, and hypoxia in vivo. METHODS: Macroscopic vascularity and ST oxygen levels were determined in vivo in patients with inflammatory arthritis who were undergoing arthroscopy. Vessel maturity\\/stability was quantified in matched ST samples by dual immunofluorescence staining for factor VIII (FVIII)\\/alpha-smooth muscle actin (alpha-SMA). NCAM and 8-oxo-7,8-dihydro-2\\'-deoxyguanosine (8-oxodG) were examined by immunohistochemistry. Angiogenesis was assessed in vitro, using human dermal endothelial cells (HDECs) in a Matrigel tube formation assay. RESULTS: A significant number of immature vessels (showing no pericyte recruitment) was observed in tissue from patients with inflammatory arthritis (P < 0.001), in contrast to osteoarthritic and normal tissue, which showed complete recruitment of pericytes. Low in vivo PO(2) levels in the inflamed joint (median [range] 22.8 [3.2-54.1] mm Hg) were inversely related to increased macroscopic vascularity (P < 0.04) and increased microscopic expression of FVIII and alpha-SMA (P < 0.04 and P < 0.03, respectively). A significant proportion of vessels showed focal expression of NCAM and strong nuclear 8-oxodG expression, implicating a loss of EC-pericyte contact and increased DNA damage, levels of which were inversely associated with low in vivo PO(2) (P = 0.04 for each comparison). Circulating cells were completely negative for 8-oxodG. Exposure of HDEC to 3% O(2) (reflecting mean ST in vivo measurements) significantly increased EC tube formation (P < 0.05). CONCLUSION: Our findings indicate the presence of unstable vessels in inflamed joints associated with hypoxia, incomplete EC-pericyte interactions, and increased DNA damage. These changes may further contribute to persistent hypoxia in the inflamed joint to further drive this unstable microenvironment.

  13. Why are tumour blood vessels abnormal and why is it important to know?

    Science.gov (United States)

    Nagy, J A; Chang, S-H; Dvorak, A M; Dvorak, H F

    2009-01-01

    Tumour blood vessels differ from their normal counterparts for reasons that have received little attention. We report here that they are of at least six distinct types, we describe how each forms, and, looking forward, encourage the targeting of tumour vessel subsets that have lost their vascular endothelial growth factor-A (VEGF-A) dependency and so are likely unresponsive to anti-VEGF-A therapies. PMID:19240721

  14. Percutaneous Retrieval of Foreign Bodies Around Vital Vessels Aided with Vascular Intervention: A Technical Note

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiu-Jun, E-mail: woothingyang2008@126.com [Shanghai Eighth People’s Hospital, Department of Radiology (China); Xing, Guang-Fu, E-mail: xgf8848@126.com [Shanghai Eighth People’s Hospital, Department of General Surgery (China)

    2015-10-15

    ObjectiveTo describe a new interventional technique to remove foreign bodies (FBs) embedded in soft tissues around vital vessels.MethodsUnder fluoroscopic guidance and using local anesthesia, percutaneous removal of FBs was performed using forceps in nine patients. All patients suffered from a metallic soft tissue FB located in close proximity to important vessels and one also had a small traumatic pseudoaneurysm adjacent to the FB. Prior to removal of the FB, the position of the nearest vessel was identified using a guide wire or catheter placed into the vessel. Balloon catheter was also simultaneously used to temporarily stop the blood flow of the nearest artery during the FB removal in three of the nine patients.ResultsAll of the nine FBs with 0–2 mm interval to the nearest vessel were successfully removed in the nine patients without any serious complications. The removed FBs measured 3–12 mm in length and 1–3 mm in width. The total fluoroscopic time of retrieval of each FB was 5–9 min (mean, 6.4 min). The volume of intraoperative bleeding ranged from 5 to 12 ml (mean, 7.5 ml). The length of hospital stay for each patient ranged from 4 to 8 days (mean, 5.5 days).ConclusionVascular intervention-aided percutaneous FB removal is minimally invasive and an effective method for removal of FBs around vital vessels.

  15. Tight junction between endothelial cells: the interaction between nanoparticles and blood vessels

    Directory of Open Access Journals (Sweden)

    Yue Zhang

    2016-05-01

    Full Text Available Since nanoparticles are now widely applied as food additives, in cosmetics and other industries, especially in medical therapy and diagnosis, we ask here whether nanoparticles can cause several adverse effects to human health. In this review, based on research on nanotoxicity, we mainly discuss the negative influence of nanoparticles on blood vessels in several aspects and the potential mechanism for nanoparticles to penetrate endothelial layers of blood vessels, which are the sites of phosphorylation of tight junction proteins (claudins, occludins, and ZO (Zonula occludens proteins, oxidative stress and shear stress. We propose a connection between the presence of nanoparticles and the regulation of the tight junction, which might be the key approach for nanoparticles to penetrate endothelial layers and then have an impact on other tissues and organs.

  16. Multi-detector spiral CT study of the relationships between pulmonary ground-glass nodules and blood vessels

    International Nuclear Information System (INIS)

    Gao, Feng; Li, Ming; Ge, Xiaojun; Ren, Qingguo; Hua, Yanqing; Zheng, Xiangpeng; Chen, Yan; Lv, Fangzhen

    2013-01-01

    To investigate the relationships between pulmonary ground-glass nodules (GGN) and blood vessels and their diagnostic values in differentiating GGNs. Multi-detector spiral CT imaging of 108 GGNs was retrospectively reviewed. The spatial relationships between GGNs and supplying blood vessels were categorized into four types: I, vessels passing by GGNs; II, intact vessels passing through GGNs; III, distorted, dilated or tortuous vessels seen within GGNs; IV, more complicated vasculature other than described above. Relationship types were correlated to pathologic and/or clinical findings of GGNs. Of 108 GGNs, 10 were benign, 24 preinvasive nodules and 74 adenocarcinomas that were pathologically proven. Types I, II, III and IV vascular relationships were observed in 9, 58, 21 and 20 GGNs, respectively. Type II relationship was the dominating relationship for each GGN group, but significant differences were shown among them. Correlation analysis showed strong correlation between invasive adenocarcinoma and type III and IV relationships. Subgroup analysis indicated that type III was more commonly seen in IAC with comparison to type IV more likely seen in MIA. Different GGNs have different relationships with vessels. Understanding and recognising characteristic GGN-vessel relationships may help identify which GGNs are more likely to be malignant. (orig.)

  17. Neutrophil-Mediated Delivery of Therapeutic Nanoparticles across Blood Vessel Barrier for Treatment of Inflammation and Infection

    OpenAIRE

    Chu, Dafeng; Gao, Jin; Wang, Zhenjia

    2015-01-01

    Endothelial cells form a monolayer in lumen of blood vessels presenting a great barrier for delivery of therapeutic nanoparticles (NPs) into extravascular tissues where most diseases occur, such as inflammation disorders and infection. Here, we report a strategy for delivering therapeutic NPs across this blood vessel barrier by nanoparticle in situ hitchhiking activated neutrophils. Using intravital microscopy of TNF-α-induced inflammation of mouse cremaster venules and a mouse model of acute...

  18. In vivo measurement of hemodynamic information in stenosed rat blood vessels using X-ray PIV.

    Science.gov (United States)

    Park, Hanwook; Park, Jun Hong; Lee, Sang Joon

    2016-11-28

    Measurements of the hemodynamic information of blood flows, especially wall shear stress (WSS), in animal models with circulatory vascular diseases (CVDs) are important to understand the pathological mechanism of CVDs. In this study, X-ray particle image velocimetry (PIV) with high spatial resolution was applied to obtain velocity field information in stenosed blood vessels with high WSS. 3D clips fabricated with a 3D printer were applied to the abdominal aorta of a rat cadaver to induce artificial stenosis in the real blood vessel of an animal model. The velocity and WSS information of blood flows in the stenosed vessel were obtained and compared at various stenosis severities. In vivo measurement was also conducted by fastening a stenotic clip on a live rat model through surgical intervention to reduce the flow rate to match the limited temporal resolution of the present X-ray PIV system. Further improvement of the temporal resolution of the system might be able to provide in vivo measurements of hemodynamic information from animal disease models under physiological conditions. The present results would be helpful for understanding the relation between hemodynamic characteristics and the pathological mechanism in animal CVD models.

  19. Delayed astrocytic contact with cerebral blood vessels in FGF-2 deficient mice does not compromise permeability properties at the developing blood-brain barrier.

    Science.gov (United States)

    Saunders, Norman R; Dziegielewska, Katarzyna M; Unsicker, Klaus; Ek, C Joakim

    2016-11-01

    The brain functions within a specialized environment tightly controlled by brain barrier mechanisms. Understanding the regulation of barrier formation is important for understanding brain development and may also lead to finding new ways to deliver pharmacotherapies to the brain; access of many potentially promising drugs is severely hindered by these barrier mechanisms. The cellular composition of the neurovascular unit of the blood-brain barrier proper and their effects on regulation of its function are beginning to be understood. One hallmark of the neurovascular unit in the adult is the astroglial foot processes that tightly surround cerebral blood vessels. However their role in barrier formation is still unclear. In this study we examined barrier function in newborn, juvenile and adult mice lacking fibroblast growth factor-2 (FGF-2), which has been shown to result in altered astroglial differentiation during development. We show that during development of FGF-2 deficient mice the astroglial contacts with cerebral blood vessels are delayed compared with wild-type animals. However, this delay did not result in changes to the permeability properties of the blood brain barrier as assessed by exclusion of either small or larger sized molecules at this interface. In addition cerebral vessels were positive for tight-junction proteins and we observed no difference in the ultrastructure of the tight-junctions. The results indicate that the direct contact of astroglia processes to cerebral blood vessels is not necessary for either the formation of the tight-junctions or for basic permeability properties and function of the blood-brain barrier. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 76: 1201-1212, 2016. © 2016 Wiley Periodicals, Inc.

  20. Vascular Patterns in Iguanas and Other Squamates: Blood Vessels and Sites of Thermal Exchange.

    Directory of Open Access Journals (Sweden)

    William Ruger Porter

    Full Text Available Squamates use the circulatory system to regulate body and head temperatures during both heating and cooling. The flexibility of this system, which possibly exceeds that of endotherms, offers a number of physiological mechanisms to gain or retain heat (e.g., increase peripheral blood flow and heart rate, cooling the head to prolong basking time for the body as well as to shed heat (modulate peripheral blood flow, expose sites of thermal exchange. Squamates also have the ability to establish and maintain the same head-to-body temperature differential that birds, crocodilians, and mammals demonstrate, but without a discrete rete or other vascular physiological device. Squamates offer important anatomical and phylogenetic evidence for the inference of the blood vessels of dinosaurs and other extinct archosaurs in that they shed light on the basal diapsid condition. Given this basal positioning, squamates likewise inform and constrain the range of physiological thermoregulatory mechanisms that may have been found in Dinosauria. Unfortunately, the literature on squamate vascular anatomy is limited. Cephalic vascular anatomy of green iguanas (Iguana iguana was investigated using a differential-contrast, dual-vascular injection (DCDVI technique and high-resolution X-ray microcomputed tomography (μCT. Blood vessels were digitally segmented to create a surface representation of vascular pathways. Known sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in brain and cephalic thermoregulation. Blood vessels to and from sites of thermal exchange were investigated to detect conserved vascular patterns and to assess their ability to deliver cooled blood to the dural venous sinuses. Arteries within sites of thermal exchange were found to deliver blood directly and through collateral pathways. The venous drainage was found to have multiple pathways that could influence neurosensory

  1. Vascular Patterns in Iguanas and Other Squamates: Blood Vessels and Sites of Thermal Exchange.

    Science.gov (United States)

    Porter, William Ruger; Witmer, Lawrence M

    2015-01-01

    Squamates use the circulatory system to regulate body and head temperatures during both heating and cooling. The flexibility of this system, which possibly exceeds that of endotherms, offers a number of physiological mechanisms to gain or retain heat (e.g., increase peripheral blood flow and heart rate, cooling the head to prolong basking time for the body) as well as to shed heat (modulate peripheral blood flow, expose sites of thermal exchange). Squamates also have the ability to establish and maintain the same head-to-body temperature differential that birds, crocodilians, and mammals demonstrate, but without a discrete rete or other vascular physiological device. Squamates offer important anatomical and phylogenetic evidence for the inference of the blood vessels of dinosaurs and other extinct archosaurs in that they shed light on the basal diapsid condition. Given this basal positioning, squamates likewise inform and constrain the range of physiological thermoregulatory mechanisms that may have been found in Dinosauria. Unfortunately, the literature on squamate vascular anatomy is limited. Cephalic vascular anatomy of green iguanas (Iguana iguana) was investigated using a differential-contrast, dual-vascular injection (DCDVI) technique and high-resolution X-ray microcomputed tomography (μCT). Blood vessels were digitally segmented to create a surface representation of vascular pathways. Known sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in brain and cephalic thermoregulation. Blood vessels to and from sites of thermal exchange were investigated to detect conserved vascular patterns and to assess their ability to deliver cooled blood to the dural venous sinuses. Arteries within sites of thermal exchange were found to deliver blood directly and through collateral pathways. The venous drainage was found to have multiple pathways that could influence neurosensory tissue temperature

  2. Regulation of cellular communication by signaling microdomains in the blood vessel wall.

    Science.gov (United States)

    Billaud, Marie; Lohman, Alexander W; Johnstone, Scott R; Biwer, Lauren A; Mutchler, Stephanie; Isakson, Brant E

    2014-01-01

    It has become increasingly clear that the accumulation of proteins in specific regions of the plasma membrane can facilitate cellular communication. These regions, termed signaling microdomains, are found throughout the blood vessel wall where cellular communication, both within and between cell types, must be tightly regulated to maintain proper vascular function. We will define a cellular signaling microdomain and apply this definition to the plethora of means by which cellular communication has been hypothesized to occur in the blood vessel wall. To that end, we make a case for three broad areas of cellular communication where signaling microdomains could play an important role: 1) paracrine release of free radicals and gaseous molecules such as nitric oxide and reactive oxygen species; 2) role of ion channels including gap junctions and potassium channels, especially those associated with the endothelium-derived hyperpolarization mediated signaling, and lastly, 3) mechanism of exocytosis that has considerable oversight by signaling microdomains, especially those associated with the release of von Willebrand factor. When summed, we believe that it is clear that the organization and regulation of signaling microdomains is an essential component to vessel wall function.

  3. Adaptable three-dimensional Monte Carlo modeling of imaged blood vessels in skin

    Science.gov (United States)

    Pfefer, T. Joshua; Barton, Jennifer K.; Chan, Eric K.; Ducros, Mathieu G.; Sorg, Brian S.; Milner, Thomas E.; Nelson, J. Stuart; Welch, Ashley J.

    1997-06-01

    In order to reach a higher level of accuracy in simulation of port wine stain treatment, we propose to discard the typical layered geometry and cylindrical blood vessel assumptions made in optical models and use imaging techniques to define actual tissue geometry. Two main additions to the typical 3D, weighted photon, variable step size Monte Carlo routine were necessary to achieve this goal. First, optical low coherence reflectometry (OLCR) images of rat skin were used to specify a 3D material array, with each entry assigned a label to represent the type of tissue in that particular voxel. Second, the Monte Carlo algorithm was altered so that when a photon crosses into a new voxel, the remaining path length is recalculated using the new optical properties, as specified by the material array. The model has shown good agreement with data from the literature. Monte Carlo simulations using OLCR images of asymmetrically curved blood vessels show various effects such as shading, scattering-induced peaks at vessel surfaces, and directionality-induced gradients in energy deposition. In conclusion, this augmentation of the Monte Carlo method can accurately simulate light transport for a wide variety of nonhomogeneous tissue geometries.

  4. Regulation of Cellular Communication by Signaling Microdomains in the Blood Vessel Wall

    Science.gov (United States)

    Billaud, Marie; Lohman, Alexander W.; Johnstone, Scott R.; Biwer, Lauren A.; Mutchler, Stephanie; Isakson, Brant E.

    2014-01-01

    It has become increasingly clear that the accumulation of proteins in specific regions of the plasma membrane can facilitate cellular communication. These regions, termed signaling microdomains, are found throughout the blood vessel wall where cellular communication, both within and between cell types, must be tightly regulated to maintain proper vascular function. We will define a cellular signaling microdomain and apply this definition to the plethora of means by which cellular communication has been hypothesized to occur in the blood vessel wall. To that end, we make a case for three broad areas of cellular communication where signaling microdomains could play an important role: 1) paracrine release of free radicals and gaseous molecules such as nitric oxide and reactive oxygen species; 2) role of ion channels including gap junctions and potassium channels, especially those associated with the endothelium-derived hyperpolarization mediated signaling, and lastly, 3) mechanism of exocytosis that has considerable oversight by signaling microdomains, especially those associated with the release of von Willebrand factor. When summed, we believe that it is clear that the organization and regulation of signaling microdomains is an essential component to vessel wall function. PMID:24671377

  5. Magnetic navigation system for the precise helical and translational motions of a microrobot in human blood vessels

    Science.gov (United States)

    Jeon, S. M.; Jang, G. H.; Choi, H. C.; Park, S. H.; Park, J. O.

    2012-04-01

    Different magnetic navigation systems (MNSs) have been investigated for the wireless manipulation of microrobots in human blood vessels. Here we propose a MNS and methodology for generation of both the precise helical and translational motions of a microrobot to improve its maneuverability in complex human blood vessel. We then present experiments demonstrating the helical and translational motions of a spiral-type microrobot to verify the proposed MNS.

  6. Study on decay heat removal capability of reactor vessel auxiliary cooling system

    International Nuclear Information System (INIS)

    Nishi, Y.; Kinoshita, I.

    1991-01-01

    The reactor vessel auxiliary cooling system (RVACS) is a simple, Passive decay heat removal system for an LMFBR. However, the heat removal capacity of this system is small compared to that of an immersed type of decay heat exchanger. In this study, a high-porosity porous body is proposed to enhance the RVACS's heat transfer performance to improve its applicability. The objectives of this study are to propose a new method which is able to use thermal radiation effectively, to confirm its heat removal capability and to estimate its applicability limit of RVACS for an LMFBR. Heat transfer tests were conducted in an experimental facility with a 3.5 m heat transfer height to evaluate the heat transfer performance of the high-porosity porous body. Using the experimental results, plant transient analyses were performed for a 300 MWe pool type LMFBR under a Total Black Out (TBO) condition to confirm the heat removal capability. Furthermore, the relationship between heat removal capability and thermal output of a reactor were evaluated using a simple parameter model

  7. The effect of transluminal stent-graft placement on blood flow of abdominal branch vessels in type B aortic dissection

    International Nuclear Information System (INIS)

    Huang Lianjun; Yang Jian; Yu Feicheng; Sun Lizhong; Zhu Junming; Zhang Yan; Jiang Shiliang

    2005-01-01

    Objective: To evaluate the effect of TSGP on blood flow of abdominal branch vessels of Type B dissection. Methods: Thirty-five patients with type B aortic dissection underwent TSGP. The blood flow of abdominal branch vessels was analyzed via EBCT, MRI, and DSA before and after procedure. Results: A total of 140 important vessels from abdominal aorta in 35 patients, including celiac artery, SMA, right and left renal arteries were analyzed via EBCT, MRI, and DSA. 58 branches were affected by dissection, of which 14 (10% ) were dynamic impairment; and 44 (31.4%) were static impairment. After TSGP, the blood flow of impaired branches all showed improvement at different degrees, no post-operative ischemic complications occurred. Conclusion: TSGP could improve the blood flow immediately not only the dynamic but also the static ischemia of abdominal aorta branch vessels caused by type B aortic dissection. Further study is still need to observe the mid-term and long-term effect of TSGP. (authors)

  8. [Conjunct changes in the resistance and engorgement of the cerebral vessels in shifts in the blood gas composition].

    Science.gov (United States)

    Krasil'nikov, V G; Artem'eva, A I

    1982-08-01

    In anesthetized cats, under perfusion and with constant volume of the hemodynamically isolated brain, hypercapnia and hypoxia led to a decrease of cerebral vessels resistance and to a reduction of the brain blood flow, whereas a decrease in the PCO2 and an increase in the PO2 in the blood exerted on opposite effect. The different responses of the vessels had some similar features in respect to threshold changes of the PCO2 and PO2, to potentiation of effects of both parts of the brain vascular system on increased shifts of the blood gas tension, to greater sensitivity of both parts to PCO2 changes, to effect of the blood gas tension on reactivity of both parts to noradrenaline. The authors suggest a possibility of alterations of the filter-absorption interrelationships in the brain due to different responses of arterial and venous vessels to changes of the blood gas tension.

  9. Extraction of liver volumetry based on blood vessel from the portal phase CT dataset

    Science.gov (United States)

    Maklad, Ahmed S.; Matsuhiro, Mikio; Suzuki, Hidenobu; Kawata, Yoshiki; Niki, Noboru; Utsunomiya, Tohru; Shimada, Mitsuo

    2012-02-01

    At liver surgery planning stage, the liver volumetry would be essential for surgeons. Main problem at liver extraction is the wide variability of livers in shapes and sizes. Since, hepatic blood vessels structure varies from a person to another and covers liver region, the present method uses that information for extraction of liver in two stages. The first stage is to extract abdominal blood vessels in the form of hepatic and nonhepatic blood vessels. At the second stage, extracted vessels are used to control extraction of liver region automatically. Contrast enhanced CT datasets at only the portal phase of 50 cases is used. Those data include 30 abnormal livers. A reference for all cases is done through a comparison of two experts labeling results and correction of their inter-reader variability. Results of the proposed method agree with the reference at an average rate of 97.8%. Through application of different metrics mentioned at MICCAI workshop for liver segmentation, it is found that: volume overlap error is 4.4%, volume difference is 0.3%, average symmetric distance is 0.7 mm, Root mean square symmetric distance is 0.8 mm, and maximum distance is 15.8 mm. These results represent the average of overall data and show an improved accuracy compared to current liver segmentation methods. It seems to be a promising method for extraction of liver volumetry of various shapes and sizes.

  10. Primo vessel inside a lymph vessel emerging from a cancer tissue.

    Science.gov (United States)

    Lee, Sungwoo; Ryu, Yeonhee; Cha, Jinmyung; Lee, Jin-Kyu; Soh, Kwang-Sup; Kim, Sungchul; Lim, Jaekwan

    2012-10-01

    Primo vessels were observed inside the lymph vessels near the caudal vena cava of a rabbit and a rat and in the thoracic lymph duct of a mouse. In the current work we found a primo vessel inside the lymph vessel that came out from the tumor tissue of a mouse. A cancer model of a nude mouse was made with human lung cancer cell line NCI-H460. We injected fluorescent nanoparticles into the xenografted tumor tissue and studied their flow in blood, lymph, and primo vessels. Fluorescent nanoparticles flowed through the blood vessels quickly in few minutes, and but slowly in the lymph vessels. The bright fluorescent signals of nanoparticles disappeared within one hour in the blood vessels but remained much longer up to several hours in the case of lymph vessels. We found an exceptional case of lymph vessels that remained bright with fluorescence up to 24 hours. After detailed examination we found that the bright fluorescence was due to a putative primo vessel inside the lymph vessel. This rare observation is consistent with Bong-Han Kim's claim on the presence of a primo vascular system in lymph vessels. It provides a significant suggestion on the cancer metastasis through primo vessels and lymph vessels. Copyright © 2012. Published by Elsevier B.V.

  11. [Do double gloves protect against contamination during cannulation of blood vessels? A prospective randomized study].

    Science.gov (United States)

    Szarpak, Łukasz; Kurowski, Andrzej

    2014-01-01

    Undamaged medical gloves protect medical personnel from contact with physiological fluids of the patient. Thus they protect the assistance provider from hand skin contamination with potentially infectious biological materials. The aim of the study was to evaluate the occurrence of pierce, perforations or damage of medical gloves during cannulation of blood vessels. In the prospective randomized study 303 pairs of gloves, used during cannulation of blood vessels under simulated resuscitation, were analyzed. Gloves were tested by the water leak test. The water test revealed 44 cases of damage to the gloves used during cannulation of blood vessels. Significant differences were noted in the frequency of damage to both the outer and single pairs of gloves and the inner pair of gloves. The study showed that the use of double gloves provides a higher level of security for a paramedic than the use of a single pair of gloves, however, double gloves reduce the manual dexterity of a paramedic. A large number of damages to gloves are not noticed by medical personnel during surgery.

  12. [Stem and progenitor cells in biostructure of blood vessel walls].

    Science.gov (United States)

    Korta, Krzysztof; Kupczyk, Piotr; Skóra, Jan; Pupka, Artur; Zejler, Paweł; Hołysz, Marcin; Gajda, Mariusz; Nowakowska, Beata; Barć, Piotr; Dorobisz, Andrzej T; Dawiskiba, Tomasz; Szyber, Piotr; Bar, Julia

    2013-09-18

    Development of vascular and hematopoietic systems during organogenesis occurs at the same time. During vasculogenesis, a small part of cells does not undergo complete differentiation but stays on this level, "anchored" in tissue structures described as stem cell niches. The presence of blood vessels within tissue stem cell niches is typical and led to identification of niches and ensures that they are functioning. The three-layer biostructure of vessel walls for artery and vein, tunica: intima, media and adventitia, for a long time was defined as a mechanical barrier between vessel light and the local tissue environment. Recent findings from vascular biology studies indicate that vessel walls are dynamic biostructures, which are equipped with stem and progenitor cells, described as vascular wall-resident stem cells/progenitor cells (VW-SC/PC). Distinct zones for vessel wall harbor heterogeneous subpopulations of VW-SC/PC, which are described as "subendothelial or vasculogenic zones". Recent evidence from in vitro and in vivo studies show that prenatal activity of stem and progenitor cells is not only limited to organogenesis but also exists in postnatal life, where it is responsible for vessel wall homeostasis, remodeling and regeneration. It is believed that VW-SC/PC could be engaged in progression of vascular disorders and development of neointima. We would like to summarize current knowledge about mesenchymal and progenitor stem cell phenotype with special attention to distribution and biological properties of VW-SC/PC in biostructures of intima, media and adventitia niches. It is postulated that in the near future, niches for VW-SC/PC could be a good source of stem and progenitor cells, especially in the context of vessel tissue bioengineering as a new alternative to traditional revascularization therapies.

  13. Stem and progenitor cells in biostructure of blood vessel walls

    Directory of Open Access Journals (Sweden)

    Krzysztof Korta

    2013-09-01

    Full Text Available Development of vascular and hematopoietic systems during organogenesis occurs at the same time. During vasculogenesis, a small part of cells does not undergo complete differentiation but stays on this level, “anchored” in tissue structures described as stem cell niches. The presence of blood vessels within tissue stem cell niches is typical and led to identification of niches and ensures that they are functioning. The three-layer biostructure of vessel walls for artery and vein, tunica: intima, media and adventitia, for a long time was defined as a mechanical barrier between vessel light and the local tissue environment. Recent findings from vascular biology studies indicate that vessel walls are dynamic biostructures, which are equipped with stem and progenitor cells, described as vascular wall-resident stem cells/progenitor cells (VW-SC/PC. Distinct zones for vessel wall harbor heterogeneous subpopulations of VW-SC/PC, which are described as “subendothelial or vasculogenic zones”. Recent evidence from in vitro and in vivo studies show that prenatal activity of stem and progenitor cells is not only limited to organogenesis but also exists in postnatal life, where it is responsible for vessel wall homeostasis, remodeling and regeneration. It is believed that VW-SC/PC could be engaged in progression of vascular disorders and development of neointima. We would like to summarize current knowledge about mesenchymal and progenitor stem cell phenotype with special attention to distribution and biological properties of VW-SC/PC in biostructures of intima, media and adventitia niches. It is postulated that in the near future, niches for VW-SC/PC could be a good source of stem and progenitor cells, especially in the context of vessel tissue bioengineering as a new alternative to traditional revascularization therapies.

  14. Case study for one-piece removal method of reactor vessel of nuclear ship 'Mutsu'

    International Nuclear Information System (INIS)

    Nagane, Satoru; Kitahara, Katsumi; Yoshikawa, Seiji; Miyasaka, Yasuhiko; Fukumura, Nobuo; Nisizawa, Ichiou

    2010-01-01

    A reactor installed at the center part of the nuclear ship 'Mutsu' has been stored safely and exhibited in a reactor room building since 1996. The reactor vessel and its internals are key components because of main radioactive wastes for the reasonable decommissioning plan in the future. This report describes the one-piece removal method as the one package of the reactor vessel with its internals intact with a shipping container or additional shields. The reactor vessel package (Max.100ton) will be classified acceptable for burial at the low level radioactive waste (LLW), which will be buried at a LLW pit facility under waste disposal regulations. And also, the package will be classified as an IP-2-equivalent package according to the requirement for Shipments and Packagings. (author)

  15. The Behaviors of Ferro-Magnetic Nano-Particles In and Around Blood Vessels under Applied Magnetic Fields

    Science.gov (United States)

    Nacev, A.; Beni, C.; Bruno, O.; Shapiro, B.

    2010-01-01

    In magnetic drug delivery, therapeutic magnetizable particles are typically injected into the blood stream and magnets are then used to concentrate them to disease locations. The behavior of such particles in-vivo is complex and is governed by blood convection, diffusion (in blood and in tissue), extravasation, and the applied magnetic fields. Using physical first-principles and a sophisticated vessel-membrane-tissue (VMT) numerical solver, we comprehensively analyze in detail the behavior of magnetic particles in blood vessels and surrounding tissue. For any blood vessel (of any size, depth, and blood velocity) and tissue properties, particle size and applied magnetic fields, we consider a Krogh tissue cylinder geometry and solve for the resulting spatial distribution of particles. We find that there are three prototypical behaviors (blood velocity dominated, magnetic force dominated, and boundary-layer formation) and that the type of behavior observed is uniquely determined by three non-dimensional numbers (the magnetic-Richardson number, mass Péclet number, and Renkin reduced diffusion coefficient). Plots and equations are provided to easily read out which behavior is found under which circumstances (Figures 5, 6, 7, and 8). We compare our results to previously published in-vitro and in-vivo magnetic drug delivery experiments. Not only do we find excellent agreement between our predictions and prior experimental observations, but we are also able to qualitatively and quantitatively explain behavior that was previously not understood. PMID:21278859

  16. Migraine aura pathophysiology: the role of blood vessels and microembolisation

    OpenAIRE

    Dalkara, Turgay; Nozari, Ala; Moskowitz, Michael A

    2010-01-01

    Migraine attacks with auras are sometimes associated with underlying hereditary or acquired cerebrovascular disorders. A unifying pathophysiological explanation linking migraine to these conditions has been diffcult to identify. On the basis of genetic and epidemiological evidence, we suggest that changes in blood vessels, hypoperfusion disorders, and microembolisation can cause neurovascular dysfunction and evoke cortical spreading depression, an event that is widely thought to underlie aura...

  17. Von Willebrand factor regulation of blood vessel formation.

    Science.gov (United States)

    Randi, Anna M; Smith, Koval E; Castaman, Giancarlo

    2018-06-04

    Several important physiological processes, from permeability to inflammation to haemostasis, take place at the vessel wall and are regulated by endothelial cells (EC). Thus, proteins that have been identified as regulators of one process are increasingly found to be involved in other vascular functions. Such is the case for Von Willebrand Factor (VWF), a large glycoprotein best known for its critical role in haemostasis. In vitro and in vivo studies have shown that lack of VWF causes enhanced vascularisation, both constitutively and following ischemia. This evidence is supported by studies on blood outgrowth endothelial cells (BOEC) from patients with lack of VWF synthesis (type 3 von Willebrand disease [VWD]). The molecular pathways are likely to involve VWF binding partners, such as integrin αvβ3, and components of Weibel Palade bodies (WPB), such as Angiopoietin-2 and Galectin-3, whose storage is regulated by VWF; these converge on the master regulator of angiogenesis and endothelial homeostasis, vascular endothelial growth factor (VEGF) signalling. Recent studies suggest that the roles of VWF may be tissue-specific. The ability of VWF to regulate angiogenesis has clinical implications for a subset of VWD patients with severe, intractable gastrointestinal bleeding due to vascular malformations. In this article, we review the evidence showing that VWF is involved in blood vessel formation, discuss the role of VWF high molecular weight multimers in regulating angiogenesis, and the value of studies on BOEC in developing a precision medicine approach to validate novel treatments for angiodysplasia in congenital VWD and acquired von Willebrand syndrome. Copyright © 2018 American Society of Hematology.

  18. Fibre optic confocal imaging (FOCI) of keratinocytes, blood vessels and nerves in hairless mouse skin in vivo

    Science.gov (United States)

    BUSSAU, L. J.; VO, L. T.; DELANEY, P. M.; PAPWORTH, G. D.; BARKLA, D. H.; KING, R. G.

    1998-01-01

    Fibre optic confocal imaging (FOCI) enabled subsurface fluorescence microscopy of the skin of hairless mice in vivo. Application of acridine orange enabled imaging of the layers of the epidermis. The corneocytes of the stratum corneum, the keratinocytes in the basal layers and redundant hair follicles were visualised at depths greater than 100 μm. Cellular and nuclear membranes of keratinocytes of the skin were visualised by the use of acridine orange and DIOC5(3). Imaging of the skin after injection of FITC-dextran revealed an extensive network of blood vessels with a size range up to 20 μm. Blood cells could be seen moving through dermal vessels and the blood circulation through the dermal vascular bed was video-taped. The fluorescent dye 4-di-2-ASP showed the presence of nerves fibres around the hair follicles and subsurface blood vessels. Comparison was made between images obtained in vivo using FOCI and in vitro scanning electron microscopy and conventional histology. FOCI offers the potential to study dynamic events in vivo, such as blood flow, skin growth, nerve regeneration and many pathological processes, in ways which have not previously been possible. PMID:9643419

  19. IMPROVING THE QUALITY OF NEAR-INFRARED IMAGING OF IN VIVOBLOOD VESSELS USING IMAGE FUSION METHODS

    DEFF Research Database (Denmark)

    Jensen, Andreas Kryger; Savarimuthu, Thiusius Rajeeth; Sørensen, Anders Stengaard

    2009-01-01

    We investigate methods for improving the visual quality of in vivo images of blood vessels in the human forearm. Using a near-infrared light source and a dual CCD chip camera system capable of capturing images at visual and nearinfrared spectra, we evaluate three fusion methods in terms...... of their capability of enhancing the blood vessels while preserving the spectral signature of the original color image. Furthermore, we investigate a possibility of removing hair in the images using a fusion rule based on the "a trous" stationary wavelet decomposition. The method with the best overall performance...... with both speed and quality in mind is the Intensity Injection method. Using the developed system and the methods presented in this article, it is possible to create images of high visual quality with highly emphasized blood vessels....

  20. Mathematical Modeling of Bingham Plastic Model of Blood Flow Through Stenotic Vessel

    OpenAIRE

    S.R. Verma

    2014-01-01

    The aim of the present paper is to study the axially symmetric, laminar, steady, one-dimensional flow of blood through narrow stenotic vessel. Blood is considered as Bingham plastic fluid. The analytical results such as pressure drop, resistance to flow and wall shear stress have been obtained. Effect of yield stress and shape of stenosis on resistance to flow and wall shear stress have been discussed through tables and graphically. It has been shown that resistance to flow and th...

  1. Segmentation of retinal blood vessels for detection of diabetic retinopathy: A review

    Directory of Open Access Journals (Sweden)

    Rezty Amalia Aras

    2016-05-01

    Full Text Available Diabetic detinopathy (DR is effect of diabetes mellitus to the human vision that is the major cause of blindness. Early diagnosis of DR is an important requirement in diabetes treatment. Retinal fundus image is commonly used to observe the diabetic retinopathy symptoms. It can present retinal features such as blood vessel and also capture the pathologies which may lead to DR. Blood vessel is one of retinal features which can show the retina pathologies. It can be extracted from retinal image by image processing with following stages: pre-processing, segmentation, and post-processing. This paper contains a review of public retinal image dataset and several methods from various conducted researches. All discussed methods are applicable to each researcher cases. There is no further analysis to conclude the best method which can be used for general cases. However, we suggest morphological and multiscale method that gives the best accuracy in segmentation.

  2. Removal of α-tocopherol from blood and its comparison with other lipids

    International Nuclear Information System (INIS)

    Gardner, H.K.; Vang, M.J.; Mavis, R.D.

    1986-01-01

    The blood decay curve of α-tocopherol in rats was compared with those of the two major blood lipids by labeling rat serum in vitro with 3 H-α-tocopherol (AT), 3 H-cholesterol (CHO) or 3 H-trioleoylglycerol (TO) and injecting it into the bloodstream. For the three lipids, loss from blood was biphasic. The half time of the faster decay was 2-4 minutes. The slower curve decayed with half times of 42, 289 and 990 minutes for TO, AT and CHO, respectively. This intermediate rate of AT removal is consistent with its accompanying both of the major blood lipids as they are removed by their respective mechanisms or with a process specific for AT. To investigate the role of liver in the faster curve, animals were hepatectomized. TO and CHO loss remained biphasic after liver removal. However, AT loss became monophasic, with a loss rate intermediate between the non-hepatectomized fast and slow decays. This demonstrates a central role for liver in the metabolism of blood-borne AT and a mode of removal distinct from the other two lipids

  3. Intracorneal blood removal six weeks after canaloplasty

    Directory of Open Access Journals (Sweden)

    Alberto Rossetti

    2013-01-01

    Full Text Available In a 71-year-old patient with bilateral open-angle glaucoma, intracorneal blood was found after a canaloplasty procedure in the right eye. Six weeks after surgery on ultrasound biomicroscopy examination, liquified blood and blood clots could be observed nasally in the deep corneal stroma close to the Descemet′s membrane. The intracorneal blood was washed out with balanced saline solution following deep corneal incision and lamellar dissection. Descemet′s membrane was reattached with air injection into the anterior chamber. Two months later, visual acuity improved to 20/50, intraocular pressure was 16 mm Hg without medication and confocal microscopy showed deep stromal folds and limited endothelial cell loss. Viscoelastic entering the cornea at Schwalbe′s line and reflux of blood from the collector channels to Schlemm′s canal can account for corneal hematoma. Even six weeks after canaloplasty, successful blood removal could be fulfilled without rupturing the Descemet′s membrane.

  4. Automated artery-venous classification of retinal blood vessels based on structural mapping method

    Science.gov (United States)

    Joshi, Vinayak S.; Garvin, Mona K.; Reinhardt, Joseph M.; Abramoff, Michael D.

    2012-03-01

    Retinal blood vessels show morphologic modifications in response to various retinopathies. However, the specific responses exhibited by arteries and veins may provide a precise diagnostic information, i.e., a diabetic retinopathy may be detected more accurately with the venous dilatation instead of average vessel dilatation. In order to analyze the vessel type specific morphologic modifications, the classification of a vessel network into arteries and veins is required. We previously described a method for identification and separation of retinal vessel trees; i.e. structural mapping. Therefore, we propose the artery-venous classification based on structural mapping and identification of color properties prominent to the vessel types. The mean and standard deviation of each of green channel intensity and hue channel intensity are analyzed in a region of interest around each centerline pixel of a vessel. Using the vector of color properties extracted from each centerline pixel, it is classified into one of the two clusters (artery and vein), obtained by the fuzzy-C-means clustering. According to the proportion of clustered centerline pixels in a particular vessel, and utilizing the artery-venous crossing property of retinal vessels, each vessel is assigned a label of an artery or a vein. The classification results are compared with the manually annotated ground truth (gold standard). We applied the proposed method to a dataset of 15 retinal color fundus images resulting in an accuracy of 88.28% correctly classified vessel pixels. The automated classification results match well with the gold standard suggesting its potential in artery-venous classification and the respective morphology analysis.

  5. Detection of Blood Vessels in Color Fundus Images using a Local Radon Transform

    Directory of Open Access Journals (Sweden)

    Reza Pourreza

    2010-09-01

    Full Text Available Introduction: This paper addresses a method for automatic detection of blood vessels in color fundus images which utilizes two main tools: image partitioning and local Radon transform. Material and Methods: The input images are firstly divided into overlapping windows and then the Radon transform is applied to each. The maximum of the Radon transform in each window corresponds to the probable available sub-vessel. To verify the detected sub-vessel, the maximum is compared with a predefined threshold. The verified sub-vessels are reconstructed using the Radon transform information. All detected and reconstructed sub-vessels are finally combined to make the final vessel tree. Results: The algorithm’s performance was evaluated numerically by applying it to 40 images of DRIVE database, a standard retinal image database. The vessels were extracted manually by two physicians. This database was used to test and compare the available and proposed algorithms for vessel detection in color fundus images. By comparing the output of the algorithm with the manual results, the two parameters TPR and FPR were calculated for each image and the average of TPRs and FPRs were used to plot the ROC curve. Discussion and Conclusion: Comparison of the ROC curve of this algorithm with other algorithms demonstrated the high achieved accuracy. Beside the high accuracy, the Radon transform which is integral-based makes the algorithm robust against noise.

  6. Does Physical Fitness Buffer the Relationship between Psychosocial Stress, Retinal Vessel Diameters, and Blood Pressure among Primary Schoolchildren?

    Science.gov (United States)

    Endes, Katharina; Herrmann, Christian; Colledge, Flora; Brand, Serge; Donath, Lars; Faude, Oliver; Pühse, Uwe; Hanssen, Henner; Zahner, Lukas

    2016-01-01

    Background. Strong evidence exists showing that psychosocial stress plays an important part in the development of cardiovascular diseases. Because physical inactivity is associated with less favourable retinal vessel diameter and blood pressure profiles, this study explores whether physical fitness is able to buffer the negative effects of psychosocial stress on retinal vessel diameters and blood pressure in young children. Methods. 325 primary schoolchildren (51% girls, Mage = 7.28 years) took part in this cross-sectional research project. Retinal arteriolar diameters, retinal venular diameters, arteriolar to venular ratio, and systolic and diastolic blood pressure were assessed in all children. Interactions terms between physical fitness (performance in the 20 m shuttle run test) and four indicators of psychosocial stress (parental reports of critical life events, family, peer and school stress) were tested in a series of hierarchical regression analyses. Results. Critical life events and family, peer, and school-related stress were only weakly associated with retinal vessel diameters and blood pressure. No support was found for a stress-buffering effect of physical fitness. Conclusion. More research is needed with different age groups to find out if and from what age physical fitness can protect against arteriolar vessel narrowing and the occurrence of other cardiovascular disease risk factors. PMID:27795958

  7. A computational study for investigating acoustic streaming and tissue heating during high intensity focused ultrasound through blood vessel with an obstacle

    Science.gov (United States)

    Parvin, Salma; Sultana, Aysha

    2017-06-01

    The influence of High Intensity Focused Ultrasound (HIFU) on the obstacle through blood vessel is studied numerically. A three-dimensional acoustics-thermal-fluid coupling model is employed to compute the temperature field around the obstacle through blood vessel. The model construction is based on the linear Westervelt and conjugate heat transfer equations for the obstacle through blood vessel. The system of equations is solved using Finite Element Method (FEM). We found from this three-dimensional numerical study that the rate of heat transfer is increasing from the obstacle and both the convective cooling and acoustic streaming can considerably change the temperature field.

  8. Different Effects of Implanting Sensory Nerve or Blood Vessel on the Vascularization, Neurotization, and Osteogenesis of Tissue-Engineered Bone In Vivo

    Science.gov (United States)

    Fan, Jun-jun; Mu, Tian-wang; Qin, Jun-jun; Bi, Long; Pei, Guo-xian

    2014-01-01

    To compare the different effects of implanting sensory nerve tracts or blood vessel on the osteogenesis, vascularization, and neurotization of the tissue-engineered bone in vivo, we constructed the tissue engineered bone and implanted the sensory nerve tracts (group SN), blood vessel (group VB), or nothing (group Blank) to the side channel of the bone graft to repair the femur defect in the rabbit. Better osteogenesis was observed in groups SN and VB than in group Blank, and no significant difference was found between groups SN and VB at 4, 8, and 12 weeks postoperatively. The neuropeptides expression and the number of new blood vessels in the bone tissues were increased at 8 weeks and then decreased at 12 weeks in all groups and were highest in group VB and lowest in group Blank at all three time points. We conclude that implanting either blood vessel or sensory nerve tract into the tissue-engineered bone can significantly enhance both the vascularization and neurotization simultaneously to get a better osteogenesis effect than TEB alone, and the method of implanting blood vessel has a little better effect of vascularization and neurotization but almost the same osteogenesis effect as implanting sensory nerve. PMID:25101279

  9. Blood-Vessel Mimicking Structures by Stereolithographic Fabrication of Small Porous Tubes Using Cytocompatible Polyacrylate Elastomers, Biofunctionalization and Endothelialization

    Directory of Open Access Journals (Sweden)

    Birgit Huber

    2016-04-01

    Full Text Available Blood vessel reconstruction is still an elusive goal for the development of in vitro models as well as artificial vascular grafts. In this study, we used a novel photo-curable cytocompatible polyacrylate material (PA for freeform generation of synthetic vessels. We applied stereolithography for the fabrication of arbitrary 3D tubular structures with total dimensions in the centimeter range, 300 µm wall thickness, inner diameters of 1 to 2 mm and defined pores with a constant diameter of approximately 100 µm or 200 µm. We established a rinsing protocol to remove remaining cytotoxic substances from the photo-cured PA and applied thio-modified heparin and RGDC-peptides to functionalize the PA surface for enhanced endothelial cell adhesion. A rotating seeding procedure was introduced to ensure homogenous endothelial monolayer formation at the inner luminal tube wall. We showed that endothelial cells stayed viable and adherent and aligned along the medium flow under fluid-flow conditions comparable to native capillaries. The combined technology approach comprising of freeform additive manufacturing (AM, biomimetic design, cytocompatible materials which are applicable to AM, and biofunctionalization of AM constructs has been introduced as BioRap® technology by the authors.

  10. Histomorphometric comparative study of blood vessels and their pattern in follicular cyst, odontogenic keratocyst, and ameloblastoma.

    Science.gov (United States)

    Seifi, Safora; Feizi, Farideh; Khafri, Thoraya; Aram, Mehrdad

    2013-03-01

    The present study aimed at assessment and histomorphometric analysis of intratumoral and peritumoral (cystic) blood vessels in odontogenic lesions and their pattern on their clinical behavior by immunohistochemistry and morphometry. In a descriptive and analytical cross-sectional study, 45 paraffin blocks of ameloblastoma, odontogenic keratocyst, and follicular cyst were selected and stained immunohistochemically for CD34. In each slide, images of 3 microscopic fields with the highest microvessel density in intratumoral and peritumoral (cystic) areas were captured at 40× magnification with attached camera system. Inner vascular diameter (IVD) and outer vascular diameter (OVD), cross-sectional area (CSA), and the wall thickness (WT) of the vessels were measured with Motic Plus 2 software. The vascular pattern in odontogenic lesions was analyzed. Outer vascular diameter, IVD, and CSA of the vessels in peritumoral (cystic) areas were greater in ameloblastoma than keratocyst (P = 0.001) and follicular cyst (P keratocyst and follicular cyst. Morphometric specifications of blood vessels (IVD, OVD, CSA) and their pattern in peritumoral (cystic) areas may influence the aggressive clinical behavior of ameloblastoma in comparison with keratocyst and follicular cyst.

  11. Acrylic vessel cleaning tests

    International Nuclear Information System (INIS)

    Earle, D.; Hahn, R.L.; Boger, J.; Bonvin, E.

    1997-01-01

    The acrylic vessel as constructed is dirty. The dirt includes blue tape, Al tape, grease pencil, gemak, the glue or residue form these tapes, finger prints and dust of an unknown composition but probably mostly acrylic dust. This dirt has to be removed and once removed, the vessel has to be kept clean or at least to be easily cleanable at some future stage when access becomes much more difficult. The authors report on the results of a series of tests designed: (a) to prepare typical dirty samples of acrylic; (b) to remove dirt stuck to the acrylic surface; and (c) to measure the optical quality and Th concentration after cleaning. Specifications of the vessel call for very low levels of Th which could come from tape residues, the grease pencil, or other sources of dirt. This report does not address the concerns of how to keep the vessel clean after an initial cleaning and during the removal of the scaffolding. Alconox is recommended as the cleaner of choice. This acrylic vessel will be used in the Sudbury Neutrino Observatory

  12. Did antepartum hypoxic insult caused by fetal vessel thrombosis influence the procalcitonin level in umbilical blood? A case report.

    Science.gov (United States)

    Kaneko, Masatoki; Yamauchi, Aya; Yamashita, Rie; Sato, Yuichiro; Kodama, Yuki; Sameshima, Hiroshi

    2015-11-01

    We report a case of marked elevation of the procalcitonin level in umbilical blood and neonatal blood at birth. The mother did not perceive fetal motion. Antepartum fetal heart rate monitoring showed a loss of variability and absence of acceleration. No fetal breathing movement, fetal movement, or fetal tone were observed by ultrasonography. The female neonate was delivered by cesarean section at 25 weeks of gestation, with birthweight 774 g. The umbilical arterial pH value at birth was 7.29. Mild elevation in interleukin-6 and tumor necrosis factor-α in umbilical blood were observed. Cytochrome c showed a high level in umbilical and neonatal blood at birth. Placental histopathology revealed multiple fetal vessel thrombosis in the large stem villi and chorionic vessels. The neonate showed no infectious signs throughout the neonatal period. Computed tomography at 3 months of age revealed atrophy in the cerebrum and cerebellum. At 1 year after birth, the infant showed spastic quadriplegia. In this case, antepartum asphyxia due to fetal vessel thrombosis may have influenced the elevation of procalcitonin level in umbilical blood and neonatal blood at birth. © 2015 Japan Society of Obstetrics and Gynecology.

  13. Vascular targeting of LIGHT normalizes blood vessels in primary brain cancer and induces intratumoural high endothelial venules.

    Science.gov (United States)

    He, Bo; Jabouille, Arnaud; Steri, Veronica; Johansson-Percival, Anna; Michael, Iacovos P; Kotamraju, Venkata Ramana; Junckerstorff, Reimar; Nowak, Anna K; Hamzah, Juliana; Lee, Gabriel; Bergers, Gabriele; Ganss, Ruth

    2018-06-01

    High-grade brain cancer such as glioblastoma (GBM) remains an incurable disease. A common feature of GBM is the angiogenic vasculature, which can be targeted with selected peptides for payload delivery. We assessed the ability of micelle-tagged, vascular homing peptides RGR, CGKRK and NGR to specifically bind to blood vessels in syngeneic orthotopic GBM models. By using the peptide CGKRK to deliver the tumour necrosis factor (TNF) superfamily member LIGHT (also known as TNF superfamily member 14; TNFSF14) to angiogenic tumour vessels, we have generated a reagent that normalizes the brain cancer vasculature by inducing pericyte contractility and re-establishing endothelial barrier integrity. LIGHT-mediated vascular remodelling also activates endothelia and induces intratumoural high endothelial venules (HEVs), which are specialized blood vessels for lymphocyte infiltration. Combining CGKRK-LIGHT with anti-vascular endothelial growth factor and checkpoint blockade amplified HEV frequency and T-cell accumulation in GBM, which is often sparsely infiltrated by immune effector cells, and reduced tumour burden. Furthermore, CGKRK and RGR peptides strongly bound to blood vessels in freshly resected human GBM, demonstrating shared peptide-binding activities in mouse and human primary brain tumour vessels. Thus, peptide-mediated LIGHT targeting is a highly translatable approach in primary brain cancer to reduce vascular leakiness and enhance immunotherapy. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  14. Blood vessel classification into arteries and veins in retinal images

    Science.gov (United States)

    Kondermann, Claudia; Kondermann, Daniel; Yan, Michelle

    2007-03-01

    The prevalence of diabetes is expected to increase dramatically in coming years; already today it accounts for a major proportion of the health care budget in many countries. Diabetic Retinopathy (DR), a micro vascular complication very often seen in diabetes patients, is the most common cause of visual loss in working age population of developed countries today. Since the possibility of slowing or even stopping the progress of this disease depends on the early detection of DR, an automatic analysis of fundus images would be of great help to the ophthalmologist due to the small size of the symptoms and the large number of patients. An important symptom for DR are abnormally wide veins leading to an unusually low ratio of the average diameter of arteries to veins (AVR). There are also other diseases like high blood pressure or diseases of the pancreas with one symptom being an abnormal AVR value. To determine it, a classification of vessels as arteries or veins is indispensable. As to our knowledge despite the importance there have only been two approaches to vessel classification yet. Therefore we propose an improved method. We compare two feature extraction methods and two classification methods based on support vector machines and neural networks. Given a hand-segmentation of vessels our approach achieves 95.32% correctly classified vessel pixels. This value decreases by 10% on average, if the result of a segmentation algorithm is used as basis for the classification.

  15. Retinal hemodynamic oxygen reactivity assessed by perfusion velocity, blood oximetry and vessel diameter measurements

    DEFF Research Database (Denmark)

    Klefter, Oliver Niels; Lauritsen, Anne Øberg; Larsen, Michael

    2015-01-01

    PURPOSE: To test the oxygen reactivity of a fundus photographic method of measuring macular perfusion velocity and to integrate macular perfusion velocities with measurements of retinal vessel diameters and blood oxygen saturation. METHODS: Sixteen eyes in 16 healthy volunteers were studied at two...... is a valid method for assessing macular perfusion. Results were consistent with previous observations of hyperoxic blood flow reduction using blue field entoptic and laser Doppler velocimetry. Retinal perfusion seemed to be regulated around individual set points according to blood glucose levels. Multimodal...

  16. [Topography of the blood vessels in the hilum of the kidney of Myrmecophaga tridactyla].

    Science.gov (United States)

    Souza, W M; Miglino, M A; Arantes, I G; Nascimento, A A

    1991-01-01

    The study was undertaken in 10 formol-imbibed kidneys of great anteater (Myrmecophaga tridactyla). After the dissection the following characteristics were showed: kidney blood vessels are distributed in 2 different sites, namely hilar and extrahilar, amounting 3 to 6 in the right side 3 to 7 in the left side. Arterial branches in extrahilar region range from 1 to 2 in both sides and in hilar region they present from 1 to 4 in the right and 1 to 2 in the left. Venous roots occur in 1 to 2 vessels in the right and 1 to 3 vessels in the left, occupying only the hilar region, except one case where it was present in the right side.

  17. Heterogeneity of muscarinic receptor subtypes in cerebral blood vessels

    International Nuclear Information System (INIS)

    Garcia-Villalon, A.L.; Krause, D.N.; Ehlert, F.J.; Duckles, S.P.

    1991-01-01

    The identity and distribution of muscarinic cholinergic receptor subtypes and associated signal transduction mechanisms was characterized for the cerebral circulation using correlated functional and biochemical investigations. Subtypes were distinguished by the relative affinities of a panel of muscarinic antagonists, pirenzepine, AF-DX 116 [11-2-[[2-[diethylaminomethyl]- 1-piperidinyl]acetyl]-5,11-dihydro-6H- pyrido[2,3-b][1,4]benzodiazepine-6-one], hexahydrosiladifenidol, methoctramine, 4-diphenylacetoxy-N-methylpiperidine methobromide, dicyclomine, para-fluoro-hexahydrosiladifenidol and atropine. Muscarinic receptors characterized by inhibition of [3H]quinuclidinylbenzilate binding in membranes of bovine pial arteries were of the M2 subtype. In contrast pharmacological analysis of [3H]-quinuclidinylbenzilate binding in bovine intracerebral microvessels suggests the presence of an M4 subtype. Receptors mediating endothelium-dependent vasodilation in rabbit pial arteries were of the M3 subtype, whereas muscarinic receptors stimulating endothelium-independent phosphoinositide hydrolysis in bovine pial arteries were of the M1 subtype. These findings suggest that characteristics of muscarinic receptors in cerebral blood vessels vary depending on the type of vessel, cellular location and function mediated

  18. Imaging transient blood vessel fusion events in zebrafish by correlative volume electron microscopy.

    Directory of Open Access Journals (Sweden)

    Hannah E J Armer

    Full Text Available The study of biological processes has become increasingly reliant on obtaining high-resolution spatial and temporal data through imaging techniques. As researchers demand molecular resolution of cellular events in the context of whole organisms, correlation of non-invasive live-organism imaging with electron microscopy in complex three-dimensional samples becomes critical. The developing blood vessels of vertebrates form a highly complex network which cannot be imaged at high resolution using traditional methods. Here we show that the point of fusion between growing blood vessels of transgenic zebrafish, identified in live confocal microscopy, can subsequently be traced through the structure of the organism using Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM and Serial Block Face/Scanning Electron Microscopy (SBF/SEM. The resulting data give unprecedented microanatomical detail of the zebrafish and, for the first time, allow visualization of the ultrastructure of a time-limited biological event within the context of a whole organism.

  19. A Strategy for Rapid Construction of Blood Vessel-Like Structures with Complex Cell Alignments.

    Science.gov (United States)

    Wang, Nuoxin; Peng, Yunhu; Zheng, Wenfu; Tang, Lixue; Cheng, Shiyu; Yang, Junchuan; Liu, Shaoqin; Zhang, Wei; Jiang, Xingyu

    2018-04-17

    A method is developed that can rapidly produce blood vessel-like structures by bonding cell-laden electrospinning (ES) films layer by layer using fibrin glue within 90 min. This strategy allows control of cell type, cell orientation, and material composition in separate layers. Furthermore, ES films with thicker fibers (polylactic-co-glycolic acid, fiber diameter: ≈3.7 µm) are used as cell-seeding layers to facilitate the cell in-growth; those with thinner fibers (polylactic acid, fiber diameter: ≈1.8 µm) are used as outer reinforcing layers to improve the mechanical strength and reduce the liquid leakage of the scaffold. Cells grow, proliferate, and migrate well in the multilayered structure. This design aims at a new type of blood vessel substitute with flexible control of parameters and implementation of functions. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Blood circulation in the ascidian tunicate Corella inflata (Corellidae)

    Science.gov (United States)

    2016-01-01

    The body of the ascidian tunicate Corella inflata is relatively transparent. Thus, the circulatory system can be visualized by injecting high molecular weight fluorescein labeled dextran into the heart or the large vessels at the ends of the heart without surgery to remove the body wall. In addition, after staining with neutral red, the movement of blood cells can be easily followed to further characterize the circulatory system. The heart is two gently curved concentric tubes extending across the width of the animal. The inner myocardial tube has a partial constriction approximately in the middle. As in other tunicates, the heart is peristaltic and periodically reverses direction. During the branchial phase blood leaves the anterior end of the heart by two asymmetric vessels that connect to the two sides of the branchial basket. Blood then flows in both transverse directions through a complex system of ducts in the basket into large ventral and dorsal vessels which carry blood back to the visceral organs in the posterior of the animal. During the visceral phase blood leaves the posterior end of the heart in two vessels that repeatedly bifurcate and fan into the stomach and gonads. Blood velocity, determined by following individual cells in video frames, is high and pulsatory near the heart. A double peak in velocity at the maximum may be due to the constriction in the middle of the heart tube. Blood velocity progressively decreases with distance from the heart. In peripheral regions with vessels of small diameter blood cells frequently collide with vessel walls and cell motion is erratic. The estimated volume of blood flow during each directional phase is greater than the total volume of the animal. Circulating blood cells are confined to vessels or ducts in the visible parts of the animal and retention of high molecular weight dextran in the vessels is comparable to that seen in vertebrates. These are characteristics of a closed circulatory system. PMID:27994977

  1. In-vessel inspection before head removal: TMI II, Phase III (tooling and systems design and verification)

    International Nuclear Information System (INIS)

    Carter, G.S.; Ryan, R.F.; Pieleck, A.W.; Bibb, H.Q.

    1982-09-01

    Under EG and G contract K-9003 to General Public Utilities Corporation, a Task Order was assigned to Babcock and Wilcox to develop and provide equipment to facilitate early assessment of core damage in the Three Mile Island Unit 2 reactor vessel head. Described is the work performed, the equipment developed, and the tests conducted with this equipment on various mockups used to simulate the constraints inside and outside the reactor vessel that affect the performance of the inspection. The tooling developed provides several methods of removing a few control rod drive leadscrews from the reactor, thereby providing paths into which cameras and lights may be inserted to permit video viewing of many potentially damaged areas in the reactor vessel. The tools, equipment, and cameras demonstrated that these tasks could be accomplished

  2. Rapid sealing of porcine renal blood vessels, ex vivo, using a high power, 1470-nm laser, and laparoscopic prototype

    Science.gov (United States)

    Hardy, Luke A.; Hutchens, Thomas C.; Larson, Eric R.; Gonzalez, David A.; Chang, Chun-Hung; Nau, William H.; Fried, Nathaniel M.

    2017-05-01

    Energy-based, radiofrequency (RF) and ultrasonic (US) devices currently provide rapid sealing of blood vessels during laparoscopic procedures. We are exploring infrared lasers as an alternate energy modality for vessel sealing, capable of generating less collateral thermal damage. Previous studies demonstrated feasibility of sealing vessels in an in vivo porcine model using a 1470-nm laser. However, the initial prototype was designed for testing in open surgery and featured tissue clasping and light delivery mechanisms incompatible with laparoscopic surgery. In this study, a laparoscopic prototype similar to devices currently in surgical use was developed, and performance tests were conducted on porcine renal blood vessels, ex vivo. The 5-mm outer-diameter laparoscopic prototype featured a traditional Maryland jaw configuration that enables tissue manipulation and blunt dissection. Laser energy was delivered through a 550-μm-core-diameter optical fiber with side-delivery from the lower jaw and beam dimensions of 18-mm length×1.2-mm width. The 1470-nm diode laser delivered 68 W with 3-s activation time, consistent with vessel seal times associated with RF and US-based devices. A total of 69 fresh porcine renal vessels with mean diameter of 3.3±1.7 mm were tested, ex vivo. Vessels smaller than 5-mm diameter were consistently sealed (48/51) with burst pressures greater than malignant hypertension blood pressure (180 mmHg), averaging 1038±474 mmHg. Vessels larger than 5 mm were not consistently sealed (6/18), yielding burst pressures of only 174±221 mmHg. Seal width, thermal damage zone, and thermal spread averaged 1.7±0.8, 3.4±0.7, and 1.0±0.4 mm, respectively. Results demonstrated that the 5-mm optical laparoscopic prototype consistently sealed vessels less than 5-mm diameter with low thermal spread. Further in vivo studies are planned to test the performance across a variety of vessels and tissues.

  3. Limitations of quantitative photoacoustic measurements of blood oxygenation in small vessels

    International Nuclear Information System (INIS)

    Sivaramakrishnan, Mathangi; Maslov, Konstantin; Zhang, Hao F; Stoica, George; Wang, Lihong V

    2007-01-01

    We investigate the feasibility of obtaining accurate quantitative information, such as local blood oxygenation level (sO 2 ), with a spatial resolution of about 50 μm from spectral photoacoustic (PA) measurements. The optical wavelength dependence of the peak values of the PA signals is utilized to obtain the local blood oxygenation level. In our in vitro experimental models, the PA signal amplitude is found to be linearly proportional to the blood optical absorption coefficient when using ultrasonic transducers with central frequencies high enough such that the ultrasonic wavelengths are shorter than the light penetration depth into the blood vessels. For an optical wavelength in the 578-596 nm region, with a transducer central frequency that is above 25 MHz, the sensitivity and accuracy of sO 2 inversion is shown to be better than 4%. The effect of the transducer focal position on the accuracy of quantifying blood oxygenation is found to be negligible. In vivo oxygenation measurements of rat skin microvasculature yield results consistent with those from in vitro studies, although factors specific to in vivo measurements, such as the spectral dependence of tissue optical attenuation, dramatically affect the accuracy of sO 2 quantification in vivo

  4. Modeling the Role of the Glymphatic Pathway and Cerebral Blood Vessel Properties in Alzheimer's Disease Pathogenesis.

    Science.gov (United States)

    Kyrtsos, Christina Rose; Baras, John S

    2015-01-01

    Alzheimer's disease (AD) is the most common cause of dementia in the elderly, affecting over 10% population over the age of 65 years. Clinically, AD is described by the symptom set of short term memory loss and cognitive decline, changes in mentation and behavior, and eventually long-term memory deficit as the disease progresses. On imaging studies, significant atrophy with subsequent increase in ventricular volume have been observed. Pathology on post-mortem brain specimens demonstrates the classic findings of increased beta amyloid (Aβ) deposition and the presence of neurofibrillary tangles (NFTs) within affected neurons. Neuroinflammation, dysregulation of blood-brain barrier transport and clearance, deposition of Aβ in cerebral blood vessels, vascular risk factors such as atherosclerosis and diabetes, and the presence of the apolipoprotein E4 allele have all been identified as playing possible roles in AD pathogenesis. Recent research has demonstrated the importance of the glymphatic system in the clearance of Aβ from the brain via the perivascular space surrounding cerebral blood vessels. Given the variety of hypotheses that have been proposed for AD pathogenesis, an interconnected, multilayer model offers a unique opportunity to combine these ideas into a single unifying model. Results of this model demonstrate the importance of vessel stiffness and heart rate in maintaining adequate clearance of Aβ from the brain.

  5. Comparison of the number of gingival blood vessels between type 2 diabetes mellitus and chronic periodontitis patients: An immunohistological study

    Directory of Open Access Journals (Sweden)

    Gautami Subhadra Penmetsa

    2015-01-01

    Full Text Available Background: The relationship between diabetes and periodontitis has been studied for more than 50 years and is generally agreed that the periodontal disease is more prevalent in diabetic patients compared to nondiabetics. Vascular changes like increased thickness of basement membrane in small vessels has been reported in diabetic patients, but the quantity of blood vessels in gingiva of diabetic patients has not been discussed much. The aim of this study was to compare the number of blood vessels in gingiva between chronic periodontitis (CP patients, CP with diabetes (type 2, and normal healthy gingiva. Materials and Methods: The study included 75 patients, divided into three groups of 25 patients each-Group I with healthy periodontium (HP, Group II with CP, and Group III with CP with diabetes mellitus (CPDM.Gingival biopsies were obtained from the subjects undergoing crown lengthening procedure for Group I, and in patients with CP and in CPDM biopsies were collected from teeth undergoing extraction. Sections were prepared for immune histochemical staining with CD34. Results: Difference was observed in the average number of blood vessels when compared between HP, CP, and CPDM groups. Statistical significant difference was observed when the HP and CP groups and HP and CPDM groups were compared. Conclusion: The results of the study indicated that the number of blood vessels in gingival connective tissue is significantly higher in CP and CPDM patients.

  6. X-ray PIV measurement of blood flow in deep vessels of a rat: An in vivo feasibility study.

    Science.gov (United States)

    Park, Hanwook; Yeom, Eunseop; Lee, Sang Joon

    2016-01-18

    X-ray PIV measurement is a noninvasive approach to measure opaque blood flows. However, it is not easy to measure real pulsatile blood flows in the blood vessels located at deep position of the body, because the surrounding tissues significantly attenuate the contrast of X-ray images. This study investigated the effect of surrounding tissues on X-ray beam attenuation by measuring the velocity fields of blood flows in deep vessels of a live rat. The decrease in image contrast was minimized by employing biocompatible CO2 microbubbles as tracer particles. The maximum measurable velocity of blood flows in the abdominal aorta of a rat model was found through comparative examination between the PIV measurement accuracy and the level of image contrast according to the input flow rate. Furthermore, the feasibility of using X-ray PIV to accurately measure in vivo blood flows was demonstrated by determining the velocity field of blood flows in the inferior vena cava of a rat. This study may serve as a reference in conducting in vivo X-ray PIV measurements of pulsatile blood flows in animal disease models and investigating hemodynamic characteristics and circulatory vascular diseases.

  7. Spatial distribution of diffuse, primitive, and classic amyloid-beta deposits and blood vessels in the upper laminae of the frontal cortex in Alzheimer disease.

    Science.gov (United States)

    Armstrong, R A; Cairns, N J; Lantos, P L

    1998-12-01

    The spatial distribution of the diffuse, primitive, and classic amyloid-beta deposits was studied in the upper laminae of the superior frontal gyrus in cases of sporadic Alzheimer disease (AD). Amyloid-beta-stained tissue was counterstained with collagen IV to determine whether the spatial distribution of the amyloid-beta deposits along the cortex was related to blood vessels. In all patients, amyloid-beta deposits and blood vessels were aggregated into distinct clusters and in many patients, the clusters were distributed with a regular periodicity along the cortex. The clusters of diffuse and primitive deposits did not coincide with the clusters of blood vessels in most patients. However, the clusters of classic amyloid-beta deposits coincided with those of the large diameter (>10 microm) blood vessels in all patients and with clusters of small-diameter (upper cortical laminae.

  8. Numerical modeling of the pulse wave propagation in large blood vessels based on liquid and wall interaction

    International Nuclear Information System (INIS)

    Rup, K; Dróżdż, A

    2014-01-01

    The purpose of this article is to develop a non-linear, one-dimensional model of pulse wave propagation in the arterial cardiovascular system. The model includes partial differential equations resulting from the balance of mass and momentum for the fluid-filled area and the balance equation for the area of the wall and vessels. The considered mathematical model of pulse wave propagation in the thoracic aorta section takes into account the viscous dissipation of fluid energy, realistic values of parameters describing the physicochemical properties of blood and vessel wall. Boundary and initial conditions contain the appropriate information obtained from in vivo measurements. As a result of the numerical solution of the mass and momentum balance equations for the blood and the equilibrium equation for the arterial wall area, time- dependent deformation, respective velocity profiles and blood pressure were determined.

  9. An Automatic Cognitive Graph-Based Segmentation for Detection of Blood Vessels in Retinal Images

    Directory of Open Access Journals (Sweden)

    Rasha Al Shehhi

    2016-01-01

    Full Text Available This paper presents a hierarchical graph-based segmentation for blood vessel detection in digital retinal images. This segmentation employs some of perceptual Gestalt principles: similarity, closure, continuity, and proximity to merge segments into coherent connected vessel-like patterns. The integration of Gestalt principles is based on object-based features (e.g., color and black top-hat (BTH morphology and context and graph-analysis algorithms (e.g., Dijkstra path. The segmentation framework consists of two main steps: preprocessing and multiscale graph-based segmentation. Preprocessing is to enhance lighting condition, due to low illumination contrast, and to construct necessary features to enhance vessel structure due to sensitivity of vessel patterns to multiscale/multiorientation structure. Graph-based segmentation is to decrease computational processing required for region of interest into most semantic objects. The segmentation was evaluated on three publicly available datasets. Experimental results show that preprocessing stage achieves better results compared to state-of-the-art enhancement methods. The performance of the proposed graph-based segmentation is found to be consistent and comparable to other existing methods, with improved capability of detecting small/thin vessels.

  10. A SURVEY OF RETINA BASED DISEASE IDENTIFICATION USING BLOOD VESSEL SEGMENTATION

    Directory of Open Access Journals (Sweden)

    P Kuppusamy

    2016-11-01

    Full Text Available The colour retinal photography is one of the most essential features to identify the confirmation of various eye diseases. The iris is primary attribute to authenticate the human. This research work presents the survey and comparison of various blood vessel related feature identification, segmentation, extraction and enhancement methods. Additionally, this study is observed the various databases performance for storing the images and testing in minimal time. This paper is also provides the better performance techniques based on the survey.

  11. Modeling the Role of the Glymphatic Pathway and Cerebral Blood Vessel Properties in Alzheimer's Disease Pathogenesis.

    Directory of Open Access Journals (Sweden)

    Christina Rose Kyrtsos

    Full Text Available Alzheimer's disease (AD is the most common cause of dementia in the elderly, affecting over 10% population over the age of 65 years. Clinically, AD is described by the symptom set of short term memory loss and cognitive decline, changes in mentation and behavior, and eventually long-term memory deficit as the disease progresses. On imaging studies, significant atrophy with subsequent increase in ventricular volume have been observed. Pathology on post-mortem brain specimens demonstrates the classic findings of increased beta amyloid (Aβ deposition and the presence of neurofibrillary tangles (NFTs within affected neurons. Neuroinflammation, dysregulation of blood-brain barrier transport and clearance, deposition of Aβ in cerebral blood vessels, vascular risk factors such as atherosclerosis and diabetes, and the presence of the apolipoprotein E4 allele have all been identified as playing possible roles in AD pathogenesis. Recent research has demonstrated the importance of the glymphatic system in the clearance of Aβ from the brain via the perivascular space surrounding cerebral blood vessels. Given the variety of hypotheses that have been proposed for AD pathogenesis, an interconnected, multilayer model offers a unique opportunity to combine these ideas into a single unifying model. Results of this model demonstrate the importance of vessel stiffness and heart rate in maintaining adequate clearance of Aβ from the brain.

  12. Semiautomated segmentation of blood vessels using ellipse-overlap criteria: Method and comparison to manual editing

    International Nuclear Information System (INIS)

    Shiffman, Smadar; Rubin, Geoffrey D.; Schraedley-Desmond, Pamela; Napel, Sandy

    2003-01-01

    Two-dimensional intensity-based methods for the segmentation of blood vessels from computed-tomography-angiography data often result in spurious segments that originate from other objects whose intensity distributions overlap with those of the vessels. When segmented images include spurious segments, additional methods are required to select segments that belong to the target vessels. We describe a method that allows experts to select vessel segments from sequences of segmented images with little effort. Our method uses ellipse-overlap criteria to differentiate between segments that belong to different objects and are separated in plane but are connected in the through-plane direction. To validate our method, we used it to extract vessel regions from volumes that were segmented via analysis of isolabel-contour maps, and showed that the difference between the results of our method and manually-edited results was within inter-expert variability. Although the total editing duration for our method, which included user-interaction and computer processing, exceeded that of manual editing, the extent of user interaction required for our method was about a fifth of that required for manual editing

  13. Chronic mild hypoxia promotes profound vascular remodeling in spinal cord blood vessels, preferentially in white matter, via an α5β1 integrin-mediated mechanism.

    Science.gov (United States)

    Halder, Sebok K; Kant, Ravi; Milner, Richard

    2018-05-01

    Spinal cord injury (SCI) leads to rapid destruction of neuronal tissue, resulting in devastating motor and sensory deficits. This is exacerbated by damage to spinal cord blood vessels and loss of vascular integrity. Thus, approaches that protect existing blood vessels or stimulate the growth of new blood vessels might present a novel approach to minimize loss or promote regeneration of spinal cord tissue following SCI. In light of the remarkable power of chronic mild hypoxia (CMH) to stimulate vascular remodeling in the brain, the goal of this study was to examine how CMH (8% O 2 for up to 7 days) affects blood vessel remodeling in the spinal cord. We found that CMH promoted the following: (1) endothelial proliferation and increased vascularity as a result of angiogenesis and arteriogenesis, (2) increased vascular expression of the angiogenic extracellular matrix protein fibronectin as well as concomitant increases in endothelial expression of the fibronectin receptor α5β1 integrin, (3) strongly upregulated endothelial expression of the tight junction proteins claudin-5, ZO-1 and occludin and (4) astrocyte activation. Of note, the vascular remodeling changes induced by CMH were more extensive in white matter. Interestingly, hypoxic-induced vascular remodeling in spinal cord blood vessels was markedly attenuated in mice lacking endothelial α5 integrin expression (α5-EC-KO mice). Taken together, these studies demonstrate the considerable remodeling potential of spinal cord blood vessels and highlight an important angiogenic role for the α5β1 integrin in promoting endothelial proliferation. They also imply that stimulation of the α5β1 integrin or controlled use of mild hypoxia might provide new approaches for promoting angiogenesis and improving vascular integrity in spinal cord blood vessels.

  14. Effects of X-irradiation on artificial blood vessel wall degradation by invasive tumor cells

    International Nuclear Information System (INIS)

    Heisel, M.A.; Laug, W.E.; Stowe, S.M.; Jones, P.A.

    1984-01-01

    Artificial vessel wall cultures, constructed by growing arterial endothelial cells on preformed layers of rat smooth muscle cells, were used to evaluate the effects of X-irradiation on tumor cell-induced tissue degradation. Bovine endothelial cells had radiation sensitivities similar to those of rat smooth muscle cells. Preirradiation of smooth muscle cells, before the addition of human fibrosarcoma (HT 1080) cells, did not increase the rate of degradation and destruction by the invasive cells. However, the degradation rate was decreased if the cultures were irradiated after the addition of HT 1080 cells. The presence of bovine endothelial cells markedly inhibited the destructive abilities of fibrosarcoma cells, but preirradiation of artificial vessel walls substantially decreased their capabilities to resist HT 1080-induced lysis. These findings suggest that the abilities of blood vessels to limit extravasation may be compromised by ionizing radiation

  15. Whole blood analysis rotor assembly having removable cellular sedimentation bowl

    Science.gov (United States)

    Burtis, C.A.; Johnson, W.F.

    1975-08-26

    A rotor assembly for performing photometric analyses using whole blood samples is described. Following static loading of a gross blood sample within a centrally located, removable, cell sedimentation bowl, the red blood cells in the gross sample are centrifugally separated from the plasma, the plasm displaced from the sedimentation bowl, and measured subvolumes of plasma distributed to respective sample analysis cuvettes positioned in an annular array about the rotor periphery. Means for adding reagents to the respective cuvettes are also described. (auth)

  16. High Endothelial Venules and Other Blood Vessels: Critical Regulators of Lymphoid Organ Development and Function

    Science.gov (United States)

    Ager, Ann

    2017-01-01

    The blood vasculature regulates both the development and function of secondary lymphoid organs by providing a portal for entry of hemopoietic cells. During the development of lymphoid organs in the embryo, blood vessels deliver lymphoid tissue inducer cells that initiate and sustain the development of lymphoid tissues. In adults, the blood vessels are structurally distinct from those in other organs due to the requirement for high levels of lymphocyte recruitment under non-inflammatory conditions. In lymph nodes (LNs) and Peyer’s patches, high endothelial venules (HEVs) especially adapted for lymphocyte trafficking form a spatially organized network of blood vessels, which controls both the type of lymphocyte and the site of entry into lymphoid tissues. Uniquely, HEVs express vascular addressins that regulate lymphocyte entry into lymphoid organs and are, therefore, critical to the function of lymphoid organs. Recent studies have demonstrated important roles for CD11c+ dendritic cells in the induction, as well as the maintenance, of vascular addressin expression and, therefore, the function of HEVs. Tertiary lymphoid organs (TLOs) are HEV containing LN-like structures that develop inside organized tissues undergoing chronic immune-mediated inflammation. In autoimmune lesions, the development of TLOs is thought to exacerbate disease. In cancerous tissues, the development of HEVs and TLOs is associated with improved patient outcomes in several cancers. Therefore, it is important to understand what drives the development of HEVs and TLOs and how these structures contribute to pathology. In several human diseases and experimental animal models of chronic inflammation, there are some similarities between the development and function of HEVs within LN and TLOs. This review will summarize current knowledge of how hemopoietic cells with lymphoid tissue-inducing, HEV-inducing, and HEV-maintaining properties are recruited from the bloodstream to induce the development and

  17. High-resolution ultrasound imaging and noninvasive optoacoustic monitoring of blood variables in peripheral blood vessels

    Science.gov (United States)

    Petrov, Irene Y.; Petrov, Yuriy; Prough, Donald S.; Esenaliev, Rinat O.

    2011-03-01

    Ultrasound imaging is being widely used in clinics to obtain diagnostic information non-invasively and in real time. A high-resolution ultrasound imaging platform, Vevo (VisualSonics, Inc.) provides in vivo, real-time images with exceptional resolution (up to 30 microns) using high-frequency transducers (up to 80 MHz). Recently, we built optoacoustic systems for probing radial artery and peripheral veins that can be used for noninvasive monitoring of total hemoglobin concentration, oxyhemoglobin saturation, and concentration of important endogenous and exogenous chromophores (such as ICG). In this work we used the high-resolution ultrasound imaging system Vevo 770 for visualization of the radial artery and peripheral veins and acquired corresponding optoacoustic signals from them using the optoacoustic systems. Analysis of the optoacoustic data with a specially developed algorithm allowed for measurement of blood oxygenation in the blood vessels as well as for continuous, real-time monitoring of arterial and venous blood oxygenation. Our results indicate that: 1) the optoacoustic technique (unlike pure optical approaches and other noninvasive techniques) is capable of accurate peripheral venous oxygenation measurement; and 2) peripheral venous oxygenation is dependent on skin temperature and local hemodynamics. Moreover, we performed for the first time (to the best of our knowledge) a comparative study of optoacoustic arterial oximetry and a standard pulse oximeter in humans and demonstrated superior performance of the optoacoustic arterial oximeter, in particular at low blood flow.

  18. Reactor vessel sealing plug

    International Nuclear Information System (INIS)

    Dooley, R.A.

    1986-01-01

    This invention relates to an apparatus and method for sealing the cold leg nozzles of a nuclear reactor pressure vessel from a remote location during maintenance and inspection of associated steam generators and pumps while the pressure vessel and refueling canal are filled with water. The apparatus includes a sealing plug for mechanically sealing the cold leg nozzle from the inside of a reactor pressure vessel. The sealing plugs include a primary and a secondary O-ring. An installation tool is suspended within the reactor vessel and carries the sealing plug. The tool telescopes to insert the sealing plug within the cold leg nozzle, and to subsequently remove the plug. Hydraulic means are used to activate the sealing plug, and support means serve to suspend the installation tool within the reactor vessel during installation and removal of the sealing plug

  19. Photoacoustic imaging of blood vessels with a double-ring sensor featuring a narrow angular aperture

    NARCIS (Netherlands)

    Kolkman, R.G.M.; Hondebrink, Erwin; Steenbergen, Wiendelt; van Leeuwen, Ton; de Mul, F.F.M.

    2004-01-01

    A photoacoustic double-ring sensor, featuring a narrow angular aperture, is developed for laser-induced photoacoustic imaging of blood vessels. An integrated optical fiber enables reflection-mode detection of ultrasonic waves. By using the cross-correlation between the signals detected by the two

  20. Tumor blood vessel "normalization" improves the therapeutic efficacy of boron neutron capture therapy (BNCT) in experimental oral cancer

    Energy Technology Data Exchange (ETDEWEB)

    D. W. Nigg

    2012-01-01

    We previously demonstrated the efficacy of BNCT mediated by boronophenylalanine (BPA) to treat tumors in a hamster cheek pouch model of oral cancer with no normal tissue radiotoxicity and moderate, albeit reversible, mucositis in precancerous tissue around treated tumors. It is known that boron targeting of the largest possible proportion of tumor cells contributes to the success of BNCT and that tumor blood vessel normalization improves drug delivery to the tumor. Within this context, the aim of the present study was to evaluate the effect of blood vessel normalization on the therapeutic efficacy and potential radiotoxicity of BNCT in the hamster cheek pouch model of oral cancer.

  1. Tumor blood vessel 'normalization' improves the therapeutic efficacy of boron neutron capture therapy (BNCT) in experimental oral cancer

    International Nuclear Information System (INIS)

    Nigg, D.W.

    2012-01-01

    We previously demonstrated the efficacy of BNCT mediated by boronophenylalanine (BPA) to treat tumors in a hamster cheek pouch model of oral cancer with no normal tissue radiotoxicity and moderate, albeit reversible, mucositis in precancerous tissue around treated tumors. It is known that boron targeting of the largest possible proportion of tumor cells contributes to the success of BNCT and that tumor blood vessel normalization improves drug delivery to the tumor. Within this context, the aim of the present study was to evaluate the effect of blood vessel normalization on the therapeutic efficacy and potential radiotoxicity of BNCT in the hamster cheek pouch model of oral cancer.

  2. Quantitative phase imaging characterization of tumor-associated blood vessel formation on a chip

    Science.gov (United States)

    Guo, Peng; Huang, Jing; Moses, Marsha A.

    2018-02-01

    Angiogenesis, the formation of new blood vessels from existing ones, is a biological process that has an essential role in solid tumor growth, development, and progression. Recent advances in Lab-on-a-Chip technology has created an opportunity for scientists to observe endothelial cell (EC) behaviors during the dynamic process of angiogenesis using a simple and economical in vitro platform that recapitulates in vivo blood vessel formation. Here, we use quantitative phase imaging (QPI) microscopy to continuously and non-invasively characterize the dynamic process of tumor cell-induced angiogenic sprout formation on a microfluidic chip. The live tumor cell-induced angiogenic sprouts are generated by multicellular endothelial sprouting into 3 dimensional (3D) Matrigel using human umbilical vein endothelial cells (HUVECs). By using QPI, we quantitatively measure a panel of cellular morphological and behavioral parameters of each individual EC participating in this sprouting. In this proof-of-principle study, we demonstrate that QPI is a powerful tool that can provide real-time quantitative analysis of biological processes in in vitro 3D biomimetic devices, which, in turn, can improve our understanding of the biology underlying functional tissue engineering.

  3. Subsurface thermal behaviour of tissue mimics embedded with large blood vessels during plasmonic photo-thermal therapy.

    Science.gov (United States)

    Paul, Anup; Narasimhan, Arunn; Das, Sarit K; Sengupta, Soujit; Pradeep, Thalappil

    2016-11-01

    The purpose of this study was to understand the subsurface thermal behaviour of a tissue phantom embedded with large blood vessels (LBVs) when exposed to near-infrared (NIR) radiation. The effect of the addition of nanoparticles to irradiated tissue on the thermal sink behaviour of LBVs was also studied. Experiments were performed on a tissue phantom embedded with a simulated blood vessel of 2.2 mm outer diameter (OD)/1.6 mm inner diameter (ID) with a blood flow rate of 10 mL/min. Type I collagen from bovine tendon and agar gel were used as tissue. Two different nanoparticles, gold mesoflowers (AuMS) and graphene nanostructures, were synthesised and characterised. Energy equations incorporating a laser source term based on multiple scattering theories were solved using finite element-based commercial software. The rise in temperature upon NIR irradiation was seen to vary according to the position of the blood vessel and presence of nanoparticles. While the maximum rise in temperature was about 10 °C for bare tissue, it was 19 °C for tissue embedded with gold nanostructures and 38 °C for graphene-embedded tissues. The axial temperature distribution predicted by computational simulation matched the experimental observations. A different subsurface temperature distribution has been obtained for different tissue vascular network models. The position of LBVs must be known in order to achieve optimal tissue necrosis. The simulation described here helps in predicting subsurface temperature distributions within tissues during plasmonic photo-thermal therapy so that the risks of damage and complications associated with in vivo experiments and therapy may be avoided.

  4. Gamma-secretase inhibitor treatment promotes VEGF-A-driven blood vessel growth and vascular leakage but disrupts neovascular perfusion.

    Directory of Open Access Journals (Sweden)

    Mattias Kalén

    Full Text Available The Notch signaling pathway is essential for normal development due to its role in control of cell differentiation, proliferation and survival. It is also critically involved in tumorigenesis and cancer progression. A key enzyme in the activation of Notch signaling is the gamma-secretase protein complex and therefore, gamma-secretase inhibitors (GSIs--originally developed for Alzheimer's disease--are now being evaluated in clinical trials for human malignancies. It is also clear that Notch plays an important role in angiogenesis driven by Vascular Endothelial Growth Factor A (VEGF-A--a process instrumental for tumor growth and metastasis. The effect of GSIs on tumor vasculature has not been conclusively determined. Here we report that Compound X (CX, a GSI previously reported to potently inhibit Notch signaling in vitro and in vivo, promotes angiogenic sprouting in vitro and during developmental angiogenesis in mice. Furthermore, CX treatment suppresses tumor growth in a mouse model of renal carcinoma, leads to the formation of abnormal vessels and an increased tumor vascular density. Using a rabbit model of VEGF-A-driven angiogenesis in skeletal muscle, we demonstrate that CX treatment promotes abnormal blood vessel growth characterized by vessel occlusion, disrupted blood flow, and increased vascular leakage. Based on these findings, we propose a model for how GSIs and other Notch inhibitors disrupt tumor blood vessel perfusion, which might be useful for understanding this new class of anti-cancer agents.

  5. ICG-assisted blood vessel detection during stereotactic neurosurgery: simulation study on excitation power limitations due to thermal effects in human brain tissue.

    Science.gov (United States)

    Rühm, Adrian; Göbel, Werner; Sroka, Ronald; Stepp, Herbert

    2014-09-01

    Intraoperative blood vessel detection based on intraluminal indocyanin-green (ICG) would allow to minimize the risk of blood vessel perforation during stereotactic brain tumor biopsy. For a fiber-based approach compatible with clinical conditions, the maximum tolerable excitation light power was derived from simulations of the thermal heat load on the tissue. Using the simulation software LITCIT, the temperature distribution in human brain tissue was calculated as a function of time for realistic single-fiber probes (0.72mm active diameter, numerical aperture 0.35, optional focusing to 0.29mm diameter) and for the optimum ICG excitation wavelength of 785nm. The asymptotic maximum temperature in the simulated tissue region was derived for different radiant fluxes at the distal fiber end. Worst case values were assumed for all other parameters. In addition to homogeneous (normal and tumor) brain tissue with homogeneous blood perfusion, models with localized extra blood vessels incorporated ahead of the distal fiber end were investigated. If one demands that destruction of normal brain tissue must be excluded by limiting the tissue heating to 42°C, then the radiant flux at the distal fiber end must be limited to 33mW with and 43mW without focusing. When considering extra blood vessels of 0.1mm diameter incorporated into homogeneously perfused brain tissue, the tolerable radiant flux is reduced to 22mW with and 32mW without focusing. The threshold value according to legal laser safety regulations for human skin tissue is 28.5mW. For the envisaged modality of blood vessel detection, light power limits for an application-relevant fiber configuration were determined and found to be roughly consistent with present legal regulations for skin tissue. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. A composite chitosan-gelatin bi-layered, biomimetic macroporous scaffold for blood vessel tissue engineering.

    Science.gov (United States)

    Badhe, Ravindra V; Bijukumar, Divya; Chejara, Dharmesh R; Mabrouk, Mostafa; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Kondiah, Pierre P D; Pillay, Viness

    2017-02-10

    A composite chitosan-gelatin macroporous hydrogel-based scaffold with bi-layered tubular architecture was engineered by solvent casting-co-particulate leaching. The scaffold constituted an inner macroporous layer concealed by a non-porous outer layer mimicking the 3D matrix of blood vessels with cellular adhesion and proliferation. The scaffold was evaluated for its morphological, physicochemical, physicomechanical and biodurability properties employing SEM, FTIR, DSC, XRD, porositometry, rheology and texture analysis. The fluid uptake and biodegradation in the presence of lysozymes was also investigated. Cellular attachment and proliferation was analysed using human dermal fibroblasts (HDF-a) seeded onto the scaffold and evaluated by MTT assay, SEM, and confocal microscopy. Results demonstrated that the scaffold had a desirable tensile strength=95.81±11kPa, elongation at break 112.5±13%, porosity 82% and pores between 100 and 230μm, 50% in vitro biodegradation at day 16 and proliferated fibroblasts over 20 days. These results demonstrate that scaffold may be an excellent tubular archetype for blood vessel tissue engineering. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Blood clotting and platelets: a delicate balance

    International Nuclear Information System (INIS)

    Heyns, A. du P.; Loetter, M.G.; Badenhorst, P.N.

    1988-01-01

    The Medical Research Council Blood Platelet Research Unit has studied many of the facets of platelets. The research highlights of the Unit include the following: the identification of ADPase, an enzyme found in the blood vessel wall, which breaks down adenosine diphospate (ADP) to adenosine, and which inhibits platelet aggregation; the determination of the relationship between the biochemical activity of the vessel wall with the development of atherosclerosis; the development of a method to label platelets with the compound In-111-oxine; the use of labelled platelets to study platelets in the spleen: an investigation of the life-span of platelets, which revealed how aged platelets are removed from circulation, and recently a study of methods to demonstrate in vivo activation of platelets. 1 fig

  8. Synergistic actions of blocking angiopoietin-2 and tumor necrosis factor-α in suppressing remodeling of blood vessels and lymphatics in airway inflammation.

    Science.gov (United States)

    Le, Catherine T K; Laidlaw, Grace; Morehouse, Christopher A; Naiman, Brian; Brohawn, Philip; Mustelin, Tomas; Connor, Jane R; McDonald, Donald M

    2015-11-01

    Remodeling of blood vessels and lymphatics are prominent features of sustained inflammation. Angiopoietin-2 (Ang2)/Tie2 receptor signaling and tumor necrosis factor-α (TNF)/TNF receptor signaling are known to contribute to these changes in airway inflammation after Mycoplasma pulmonis infection in mice. We determined whether Ang2 and TNF are both essential for the remodeling on blood vessels and lymphatics, and thereby influence the actions of one another. Their respective contributions to the initial stage of vascular remodeling and sprouting lymphangiogenesis were examined by comparing the effects of function-blocking antibodies to Ang2 or TNF, given individually or together during the first week after infection. As indices of efficacy, vascular enlargement, endothelial leakiness, venular marker expression, pericyte changes, and lymphatic vessel sprouting were assessed. Inhibition of Ang2 or TNF alone reduced the remodeling of blood vessels and lymphatics, but inhibition of both together completely prevented these changes. Genome-wide analysis of changes in gene expression revealed synergistic actions of the antibody combination over a broad range of genes and signaling pathways involved in inflammatory responses. These findings demonstrate that Ang2 and TNF are essential and synergistic drivers of remodeling of blood vessels and lymphatics during the initial stage of inflammation after infection. Inhibition of Ang2 and TNF together results in widespread suppression of the inflammatory response. Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  9. Improvement to reactor vessel

    International Nuclear Information System (INIS)

    1974-01-01

    The vessel described includes a prestressed concrete vessel containing a chamber and a removable cover closing this chamber. The cover is in concrete and is kept in its closed position by main and auxiliary retainers, comprising fittings integral with the concrete of the vessel. The auxiliary retainers pass through the concrete of the cover. This improvement may be applied to BWR, PWR and LMFBR type reactor vessel [fr

  10. Modeling the Role of the Glymphatic Pathway and Cerebral Blood Vessel Properties in Alzheimer’s Disease Pathogenesis

    Science.gov (United States)

    Kyrtsos, Christina Rose; Baras, John S.

    2015-01-01

    Alzheimer’s disease (AD) is the most common cause of dementia in the elderly, affecting over 10% population over the age of 65 years. Clinically, AD is described by the symptom set of short term memory loss and cognitive decline, changes in mentation and behavior, and eventually long-term memory deficit as the disease progresses. On imaging studies, significant atrophy with subsequent increase in ventricular volume have been observed. Pathology on post-mortem brain specimens demonstrates the classic findings of increased beta amyloid (Aβ) deposition and the presence of neurofibrillary tangles (NFTs) within affected neurons. Neuroinflammation, dysregulation of blood-brain barrier transport and clearance, deposition of Aβ in cerebral blood vessels, vascular risk factors such as atherosclerosis and diabetes, and the presence of the apolipoprotein E4 allele have all been identified as playing possible roles in AD pathogenesis. Recent research has demonstrated the importance of the glymphatic system in the clearance of Aβ from the brain via the perivascular space surrounding cerebral blood vessels. Given the variety of hypotheses that have been proposed for AD pathogenesis, an interconnected, multilayer model offers a unique opportunity to combine these ideas into a single unifying model. Results of this model demonstrate the importance of vessel stiffness and heart rate in maintaining adequate clearance of Aβ from the brain. PMID:26448331

  11. Automatic blood vessel based-liver segmentation using the portal phase abdominal CT

    Science.gov (United States)

    Maklad, Ahmed S.; Matsuhiro, Mikio; Suzuki, Hidenobu; Kawata, Yoshiki; Niki, Noboru; Shimada, Mitsuo; Iinuma, Gen

    2018-02-01

    Liver segmentation is the basis for computer-based planning of hepatic surgical interventions. In diagnosis and analysis of hepatic diseases and surgery planning, automatic segmentation of liver has high importance. Blood vessel (BV) has showed high performance at liver segmentation. In our previous work, we developed a semi-automatic method that segments the liver through the portal phase abdominal CT images in two stages. First stage was interactive segmentation of abdominal blood vessels (ABVs) and subsequent classification into hepatic (HBVs) and non-hepatic (non-HBVs). This stage had 5 interactions that include selective threshold for bone segmentation, selecting two seed points for kidneys segmentation, selection of inferior vena cava (IVC) entrance for starting ABVs segmentation, identification of the portal vein (PV) entrance to the liver and the IVC-exit for classifying HBVs from other ABVs (non-HBVs). Second stage is automatic segmentation of the liver based on segmented ABVs as described in [4]. For full automation of our method we developed a method [5] that segments ABVs automatically tackling the first three interactions. In this paper, we propose full automation of classifying ABVs into HBVs and non- HBVs and consequently full automation of liver segmentation that we proposed in [4]. Results illustrate that the method is effective at segmentation of the liver through the portal abdominal CT images.

  12. Size ratio performance in detecting cerebral aneurysm rupture status is insensitive to small vessel removal.

    Science.gov (United States)

    Lauric, Alexandra; Baharoglu, Merih I; Malek, Adel M

    2013-04-01

    The variable definition of size ratio (SR) for sidewall (SW) vs bifurcation (BIF) aneurysms raises confusion for lesions harboring small branches, such as carotid ophthalmic or posterior communicating locations. These aneurysms are considered SW by many clinicians, but SR methodology classifies them as BIF. To evaluate the effect of ignoring small vessels and SW vs stringent BIF labeling on SR ruptured aneurysm detection performance in borderline aneurysms with small branches, and to reconcile SR-based labeling with clinical SW/BIF classification. Catheter rotational angiographic datasets of 134 consecutive aneurysms (60 ruptured) were automatically measured in 3-dimensional. Stringent BIF labeling was applied to clinically labeled aneurysms, with 21 aneurysms switching label from SW to BIF. Parent vessel size was evaluated both taking into account, and ignoring, small vessels. SR was defined accordingly as the ratio between aneurysm and parent vessel sizes. Univariate and multivariate statistics identified significant features. The square of the correlation coefficient (R(2)) was reported for bivariate analysis of alternative SR calculations. Regardless of SW/BIF labeling method, SR was equally significant in discriminating aneurysm ruptured status (P analysis of alternative SR had a high correlation of R(2) = 0.94 on the whole dataset, and R = 0.98 on the 21 borderline aneurysms. Ignoring small branches from SR calculation maintains rupture status detection performance, while reducing postprocessing complexity and removing labeling ambiguity. Aneurysms adjacent to these vessels can be considered SW for morphometric analysis. It is reasonable to use the clinical SW/BIF labeling when using SR for rupture risk evaluation.

  13. Glucose metabolism in diabetic blood vessels

    International Nuclear Information System (INIS)

    Brown, B.J.; Crass, M.F. III

    1986-01-01

    Since glycolysis appears to be coupled to active ion transport in vascular smooth muscle, alterations in glucose metabolism may contribute to cellular dysfunction and angiopathy in diabetes. Uptake and utilization of glucose were studied in perfused blood vessels in which pulsatile flow and perfusion pressure were similar to those measured directly in vivo. Thoracic aortae isolated from 8-wk alloxan diabetic (D) and nondiabetic control rabbits were cannulated, tethered, and perfused with oxygenated buffer containing 7 or 25 mM glucose and tracer amounts of glucose-U -14 C. Norepinephrine (NE) (10 -6 M) and/or insulin (I) (150 μU/ml) and albumin (0.2%) were added. NE-induced tension development increased glucose uptake 39% and 14 CO 2 and lactate production 2.3-fold. With 7 mM glucose, marked decreases in glucose uptake (74%), 14 CO 2 (68%), lactate (30%), total tissue glycogen (75%), and tissue phospholipids (70%) were observed in D. Addition of I or elevation of exogenous glucose to 25 mM normalized glucose uptake, but had differential effects on the pattern of substrate utilization. Thus, in D, there was a marked depression of vascular glucose metabolism that was partially reversed by addition of low concentrations of insulin or D levels of glucose

  14. Rapid sealing and cutting of porcine blood vessels, ex vivo, using a high-power, 1470-nm diode laser.

    Science.gov (United States)

    Giglio, Nicholas C; Hutchens, Thomas C; Perkins, William C; Latimer, Cassandra; Ward, Arlen; Nau, William H; Fried, Nathaniel M

    2014-03-01

    Suture ligation with subsequent cutting of blood vessels to maintain hemostasis during surgery is time consuming and skill intensive. Energy-based electrosurgical and ultrasonic devices are often used to replace sutures and mechanical clips to provide rapid hemostasis and decrease surgery time. Some of these devices may create undesirably large collateral zones of thermal damage and tissue necrosis, or require separate mechanical blades for cutting. Infrared lasers are currently being explored as alternative energy sources for vessel sealing applications. In a previous study, a 1470-nm laser was used to seal vessels 1 to 6 mm in diameter in 5 s, yielding burst pressures of ∼500  mmHg. The purpose of this study was to provide vessel sealing times comparable with current energy-based devices, incorporate transection of sealed vessels, and demonstrate high vessel burst pressures to provide a safety margin for future clinical use. A 110-W, 1470-nm laser beam was transmitted through a fiber and beam shaping optics, producing a 90-W linear beam 3.0 by 9.5 mm for sealing (400  W/cm2), and 1.1 by 9.6 mm for cutting (1080  W/cm2). A two-step process sealed and then transected ex vivo porcine renal vessels (1.5 to 8.5 mm diameter) in a bench top setup. Seal and cut times were 1.0 s each. A burst pressure system measured seal strength, and histologic measurements of lateral thermal spread were also recorded. All blood vessels tested (n=55 seal samples) were sealed and cut, with total irradiation times of 2.0 s and mean burst pressures of 1305±783  mmHg. Additional unburst vessels were processed for histological analysis, showing a lateral thermal spread of 0.94±0.48  mm (n=14 seal samples). This study demonstrated that an optical-based system is capable of precisely sealing and cutting a wide range of porcine renal vessel sizes and, with further development, may provide an alternative to radiofrequency- and ultrasonic-based vessel sealing devices.

  15. Vacuum vessel for thermonuclear device

    International Nuclear Information System (INIS)

    Kikuchi, Mitsuru; Kurita, Gen-ichi; Onozuka, Masaki; Suzuki, Masaru.

    1997-01-01

    Heat of inner walls of a vacuum vessel that receive radiation heat from plasmas by way of first walls is removed by a cooling medium flowing in channels for cooling the inner walls. Nuclear heat generation of constitutional materials of the vacuum vessel caused by fast neutrons and γ rays is removed by a cooling medium flowing in cooling channels disposed in the vacuum vessel. Since the heat from plasmas and the nuclear heat generation are removed separately, the amount of the cooling medium flowing in the channels for cooling inner walls is increased for cooling a great amount of heat from plasmas while the amount of the cooling medium flowing in the channels for cooling the inside of the vacuum vessel is reduced for cooling the small amount of nuclear heat generation. Since the amount of the cooling medium can thus be optimized, the capacity of the facilities for circulating the cooling medium can be reduced. In addition, since the channels for cooling the inner walls and the channels of cooling medium formed in the vacuum vessel are disposed to the inner walls of the vacuum vessel on the side opposite to plasmas, integrity of the channels relative to leakage of the cooling medium can be ensured. (N.H.)

  16. Vacuum vessel for thermonuclear device

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Mitsuru; Kurita, Gen-ichi [Japan Atomic Energy Research Inst., Tokyo (Japan); Onozuka, Masaki; Suzuki, Masaru

    1997-07-31

    Heat of inner walls of a vacuum vessel that receive radiation heat from plasmas by way of first walls is removed by a cooling medium flowing in channels for cooling the inner walls. Nuclear heat generation of constitutional materials of the vacuum vessel caused by fast neutrons and {gamma} rays is removed by a cooling medium flowing in cooling channels disposed in the vacuum vessel. Since the heat from plasmas and the nuclear heat generation are removed separately, the amount of the cooling medium flowing in the channels for cooling inner walls is increased for cooling a great amount of heat from plasmas while the amount of the cooling medium flowing in the channels for cooling the inside of the vacuum vessel is reduced for cooling the small amount of nuclear heat generation. Since the amount of the cooling medium can thus be optimized, the capacity of the facilities for circulating the cooling medium can be reduced. In addition, since the channels for cooling the inner walls and the channels of cooling medium formed in the vacuum vessel are disposed to the inner walls of the vacuum vessel on the side opposite to plasmas, integrity of the channels relative to leakage of the cooling medium can be ensured. (N.H.)

  17. Comparison between PVHIS on the MRI and the permeability of brain blood vessels in elderly patients

    International Nuclear Information System (INIS)

    Yamaguchi, Katsuhiko; Tanaka, Yuriko; Kubo, Hideki; Takagi, Yasushi; Tachikawa, Shinzo; Katsunuma, Hideyo.

    1989-01-01

    The degree of PVHIS (periventricular high intensity signal) on the MRI was composed with the permeability of brain blood vessels using the cerebrospinal fluid (CSF)/serum ratio for albumin, and the CSF/serum ratio for IgG in elderly patients. The 47 elderly patients (mean age=79.9) were divided into three groups: (1) Mild group (20 cases, M:6, F:14, mean age=75.8), (2) Moderate group (18 cases, M:7, F:11, mean age=82.6), (3) Severe group (9 cases, M:2, F:7, mean age=82.9), in accordance with the degree of PVHIS on the MRI. The MRI was operated at a field strength of 0.22 tesla. The pulse sequence (used on all patients) had a repetition times (TR) of 2,000 msec and a time to echo (TE) of 40 msec. The levels of albumin and IgG in the serum and CSF were measured. The CSF/serum ratio for albumin was used of analyze the permeability of the brain blood vessels in each group. There was no significant difference in the level of the serum albumin, the CSF albumin, the serum IgG, the CSF IgG and the CSF/serum ratio for IgG among the three groups. The same was found to be true for the IgG index which indicates the synthesis of immunoglobulin in the central nervous system. However, there was a statistically significant difference (p<0.05) in the CSF/serum ratio for albumin between groups (1) and (3). The increased CSF/serum ratio for albumin in the severe group indicated there were confluent lesions involving the entire extent of the periventriular white matter on the MRI. This suggested an increased permeability of brain blood vessels which revealed the dysfunction of the blood brain barrier due to affected cerebral endothelial cells in capillaries. (author)

  18. Hemodynamics in stenotic vessels of small diameter under steady state conditions: Effect of viscoelasticity and migration of red blood cells.

    Science.gov (United States)

    Dimakopoulos, Yannis; Kelesidis, George; Tsouka, Sophia; Georgiou, Georgios C; Tsamopoulos, John

    2015-01-01

    In microcirculation, the non-Newtonian behavior of blood and the complexity of the microvessel network are responsible for the high flow resistance and the large reduction of the blood pressure. Red blood cell aggregation along with inward radial migration are two significant mechanisms determining the former. Yet, their impact on hemodynamics in non-straight vessels is not well understood. In this study, the steady state blood flow in stenotic rigid vessels is examined, employing a sophisticated non-homogeneous constitutive law. The effect of red blood cells migration on the hydrodynamics is quantified and the constitutive model's accuracy is evaluated. A numerical algorithm based on the two-dimensional mixed finite element method and the EVSS/SUPG technique for a stable discretization of the mass and momentum conservation equations in addition to the constitutive model is employed. The numerical simulations show that a cell-depleted layer develops along the vessel wall with an almost constant thickness for slow flow conditions. This causes the reduction of the drag force and the increase of the pressure gradient as the constriction ratio decreases. Viscoelastic effects in blood flow were found to be responsible for steeper decreases of tube and discharge hematocrits as decreasing function of constriction ratio.

  19. The effects of Anadara granosa shell-Stichopus hermanni on bFGF expressions and blood vessel counts in the bone defect healing process of Wistar rats

    Directory of Open Access Journals (Sweden)

    Rima Parwati Sari

    2017-12-01

    Full Text Available Background: Bone damage can be caused by various factors with treatment usually involving graft materials being applied to the defective area. Moreover, in the bone defect healing process, blood vessels are also considered to be an important energy source for cell proliferation. One of the angiogenic factors playing an important role in blood vessel formation is basic fibroblast growth factor (bFGF. Furthermore, synthesized hydroxyapatite derived from Anadara granosa (AG shells constitutes one of the potential materials for use in bone graft. The gold sea cucumber genus Stichopus hermanni (SH possesses the ability to stimulate endothelial progenitor cells inducing bFGF. Purpose: This study aims to investigate the effects of AG shells and SH on bFGF expressions and blood vessel counts within the bone healing process. Methods: Twenty four male Wistar rats were divided into three groups, namely: a control group (C, a treatment group was administered with blood cockle shell (AG, and a treatment group with blood cockle shell and golden sea cucumber (AG+SH. Defects were made on their femurs measuring half the diameter of a circular, no. 018. bur These rats were subsequently sacrificed on day 7 after surgery. The expressions of bFGF were measured by means of IHC technique, while the number of blood vessels was quantified using HE technique. The resulting data was subjected to statistical analysis using an Anova test followed by an LSD test (p < 0.05. Results: The one-way Anova test results combined with those of an LSD test showed there to be significant differences in bFGF expressions and blood vessel counts between the control group (K and the treatment group (AG as well as between the treatment group (AG and the treatment group (AG+SH. Conclusions: A combination of Anadara granosa shell and Stichopus hermanni can increase the expression of bFGF and the number of blood vessels on day 7 during the bone healing process in Wistar rats.

  20. C-reactive protein and chitinase 3-like protein 1 as biomarkers of spatial redistribution of retinal blood vessels on digital retinal photography in patients with diabetic retinopathy.

    Science.gov (United States)

    Cekić, Sonja; Cvetković, Tatjana; Jovanović, Ivan; Jovanović, Predrag; Pesić, Milica; Stanković Babić, Gordana; Milenković, Svetislav; Risimić, Dijana

    2014-08-20

    The aim of the study was to investigate the correlation between the levels of C-reactive protein (CRP) and chitinase 3-like protein 1 (YKL-40) in blood samples with morpohometric parameters of retinal blood vessels in patients with diabetic retinopathy. Blood laboratory examination of 90 patients included the measurement of glycemia, HbA1C, total cholesterol, LDL-C, HDL-C, triglycerides and CRP. Levels of YKL-40 were detected and measured in serum by ELISA (Micro VueYKL-40 EIA Kit, Quidel Corporation, San Diego, USA). YKL-40 correlated positively with diameter and negatively with number of retinal blood vessels. The average number of the blood vessels per retinal zone was significantly higher in the group of patients with mild non-proliferative diabetic retinopathy than in the group with severe form in the optic disc and all five retinal zones. The average outer diameter of the evaluated retinal zones and optic disc vessels was significantly higher in the group with severe compared to the group with mild diabetic retinopathy. Morphological analysis of the retinal vessels on digital fundus photography and correlation with YKL-40 may be valuable for the follow-up of diabetic retinopathy.

  1. Characterization of Adsorbents for Cytokine Removal from Blood in an In Vitro Model.

    Science.gov (United States)

    Harm, Stephan; Gabor, Franz; Hartmann, Jens

    2015-01-01

    Cytokines are basic targets that have to be removed effectively in order to improve the patient's health status in treating severe inflammation, sepsis, and septic shock. Although there are different adsorbents commercially available, the success of their clinical use is limited. Here, we tested different adsorbents for their effective removal of cytokines from plasma and the resulting effect on endothelial cell activation. The three polystyrene divinylbenzene (PS-DVB) based adsorbents Amberchrom CG161c and CG300m and a clinically approved haemoperfusion adsorbent (HAC) were studied with regard to cytokine removal in human blood. To induce cytokine release from leucocytes, human blood cells were stimulated with 1 ng/ml LPS for 4 hours. Plasma was separated and adsorption experiments in a dynamic model were performed. The effect of cytokine removal on endothelial cell activation was evaluated using a HUVEC-based cell culture model. The beneficial outcome was assessed by measuring ICAM-1, E-selectin, and secreted cytokines IL-8 and IL-6. Additionally the threshold concentration for HUVEC activation by TNF-α and IL-1β was determined using this cell culture model. CG161c showed promising results in removing the investigated cytokines. Due to its pore size the adsorbent efficiently removed the key factor TNF-α, outperforming the commercially available adsorbents. The CG161c treatment reduced cytokine secretion and expression of cell adhesion molecules by HUVEC which underlines the importance of effective removal of TNF-α in inflammatory diseases. These results confirm the hypothesis that cytokine removal from the blood should approach physiological levels in order to reduce endothelial cell activation.

  2. AN EFFICIENT TECHNIQUE FOR RETINAL VESSEL SEGMENTATION AND DENOISING USING MODIFIED ISODATA AND CLAHE

    Directory of Open Access Journals (Sweden)

    Khan Bahadar Khan

    2016-11-01

    Full Text Available Retinal damage caused due to complications of diabetes is known as Diabetic Retinopathy (DR. In this case, the vision is obscured due to the damage of retinal tinny blood vessels of the retina. These tinny blood vessels may cause leakage which affect the vision and can lead to complete blindness. Identification of these new retinal vessels and their structure is essential for analysis of DR. Automatic blood vessels segmentation plays a significant role to assist subsequent automatic methodologies that aid to such analysis. In literature most of the people have used computationally hungry a strong preprocessing steps followed by a simple thresholding and post processing, But in our proposed technique we utilize an arrangement of  light pre-processing which consists of Contrast Limited Adaptive Histogram Equalization (CLAHE for contrast enhancement, a difference image of green channel from its Gaussian blur filtered image to remove local noise or geometrical object, Modified Iterative Self Organizing Data Analysis Technique (MISODATA for segmentation of vessel and non-vessel pixels based on global and local thresholding, and a strong  post processing using region properties (area, eccentricity to eliminate the unwanted region/segment, non-vessel pixels and noise that never been used to reject misclassified foreground pixels. The strategy is tested on the publically accessible DRIVE (Digital Retinal Images for Vessel Extraction and STARE (STructured Analysis of the REtina databases. The performance of proposed technique is assessed comprehensively and the acquired accuracy, robustness, low complexity and high efficiency and very less computational time that make the method an efficient tool for automatic retinal image analysis. Proposed technique perform well as compared to the existing strategies on the online available databases in term of accuracy, sensitivity, specificity, false positive rate, true positive rate and area under receiver

  3. Supervised retinal vessel segmentation from color fundus images based on matched filtering and AdaBoost classifier.

    Directory of Open Access Journals (Sweden)

    Nogol Memari

    Full Text Available The structure and appearance of the blood vessel network in retinal fundus images is an essential part of diagnosing various problems associated with the eyes, such as diabetes and hypertension. In this paper, an automatic retinal vessel segmentation method utilizing matched filter techniques coupled with an AdaBoost classifier is proposed. The fundus image is enhanced using morphological operations, the contrast is increased using contrast limited adaptive histogram equalization (CLAHE method and the inhomogeneity is corrected using Retinex approach. Then, the blood vessels are enhanced using a combination of B-COSFIRE and Frangi matched filters. From this preprocessed image, different statistical features are computed on a pixel-wise basis and used in an AdaBoost classifier to extract the blood vessel network inside the image. Finally, the segmented images are postprocessed to remove the misclassified pixels and regions. The proposed method was validated using publicly accessible Digital Retinal Images for Vessel Extraction (DRIVE, Structured Analysis of the Retina (STARE and Child Heart and Health Study in England (CHASE_DB1 datasets commonly used for determining the accuracy of retinal vessel segmentation methods. The accuracy of the proposed segmentation method was comparable to other state of the art methods while being very close to the manual segmentation provided by the second human observer with an average accuracy of 0.972, 0.951 and 0.948 in DRIVE, STARE and CHASE_DB1 datasets, respectively.

  4. Variability of blood pressure and blood glucose during perioperative period for patients with secondary neovascular glaucoma after silicone oil removed in PDR

    Directory of Open Access Journals (Sweden)

    Fu-Lin Gao

    2015-06-01

    Full Text Available AIM:To research blood pressure and blood glucose variability during peroperative period for patients with secondary neovasular glaucoma(NVGafter silicone oil removed in proliferative diabetic retinaopathy(PDR.METHODS: Totally, 271 patients(271 eyesundergone surgery of vitrectomy and silicon-oil tamponade combined with cataract were respective analyzed. Fourteen patients(14 eyeswith secondary NVG after silicon oil removed and randomly controlled group of no NVG according with ages, operation method in the same time were studied. The blood pressure and blood glucose variability during peroperative period was analyzed, and did comparison after excluded contralateral eye. The complications of 271 patients were surveyed in following-up period 1~12mo. The incidence of NVG, the time, blood pressure, blood glucose and glycated hemoglobin(Hbc%variability during peroperative period was statisticed and compared by software of SPSS 11.0.RESULTS: Fourteen eyes(5.2%of 271 cases was with secondary NVG(female: 4 eyes, 28.6%; male: 10 eyes, 71.4%, average ages was 57.07 years(49~68 years. NVG presented in the 107~ 135d after vitrectomy and 7~45d(average 31.78dafter silicon-oil removed. Diabetes mellitus was 10~15(average 13.2a. In NVG group, the variability of blood glucose was 4.0~10.2mmol/L(mean 8.52±3.24mmol/L, variable coefficient was 0.48. In NNVG group, the variability of blood glucose was 5.0~8.2mmol/L(mean 7.22±0.24mmol/L, variable coefficient was 0.43. It was significantly difference in comparison in variable coefficient(PPPPCONCLUSION: There are significant variability on fasting blood glucose, daytime SBP and night DBP during perioperative in PDR patients with secondary NVG. It might be occurred 1wk after silicone oil removal surgery.

  5. Reactor vessel decommissioning project. Final report

    International Nuclear Information System (INIS)

    Schoonen, D.H.

    1984-09-01

    This report describes a reactor vessel decommissioning project; it documents and explains the project objectives, scope, performance results, and sodium removal process. The project was successfully completed in FY-1983, within budget and without significant problems or adverse impact on the environment. Waste generated by the operation included the reactor vessel, drained sodium, and liquid, solid, and gaseous wastes which were significantly less than project estimates. Personnel radiation exposures were minimized, such that the project total was one-half the predicted exposure level. Except for the sodium removed, the material remaining in the reactor vessel is essentially the same as when the vessel arrived for processing

  6. C - reactive protein and chitinase 3-like protein 1 as biomarkers of spatial redistribution of retinal blood vessels on digital retinal photography in patients with diabetic retinopathy

    Directory of Open Access Journals (Sweden)

    Sonja Predrag Cekic

    2014-08-01

    Full Text Available The aim of the study was to investegate the correlation between the levels of CRP and YKL-40 in blood samples with morphometric parameters of retinal blood vessels in patients with diabetic retinopathy.Blood laboratory examination of 90 patients included the measurement of glycemia, HbA1C, total cholesterol, LDL-C, HDL-C, triglycerides and CRP. Levels of YKL-40 were detected and measured in serum by ELISA (Micro VueYKL-40 EIA Kit, Quidel Corporation, San Diego, USA.Morphmetric analysis was performed with ImageJ software (http://rsbweb.nih.gov/ij/ for digital retinal photography. We measured the number, diameter of retinal blood vessels in five different parts concentric to the optic disc. Differences between the morphometric parameters and the blood test analysis results were evaluated using the Student’s t – test. One Way ANOVA was used to establish the significance of differences.CRP and YKL-40 levels were moderately higher in the group of patients with severe diabetic retinopathy. Levels of YKL-40 correlated positively with diameter and negatively with number of retinal blood vessels. The average number of the blood vessels per retinal zone was significantly higher in the group of patients with mild non-proliferative diabetic retinopathy than in the group with severe form in the optic disc and all five retinal zones. The average outer diameter of the evaluated retinal zones and optic disc vessels was significantly higher in the group with severe compared to the group with mild diabetic retinopathy.Morphological analysis of the retinal vessels on digital fundus photography and correlation with YKL-40 may be valuable for the follow-up of diabetic retinopathy.

  7. Effect of heat transfer on unsteady MHD flow of blood in a permeable vessel in the presence of non-uniform heat source

    OpenAIRE

    A. Sinha; J.C. Misra; G.C. Shit

    2016-01-01

    This paper presents a theoretical analysis of blood flow and heat transfer in a permeable vessel in the presence of an external magnetic field. The unsteadiness in the coupled flow and temperature fields is considered to be caused due to the time-dependent stretching velocity and the surface temperature of the vessel. The non-uniform heat source/sink effect on blood flow and heat transfer is taken into account. This study is of potential value in the clinical treatment of cardiovascular disor...

  8. Reactor vessel stud closure system

    International Nuclear Information System (INIS)

    Spiegelman, S.R.; Salton, R.B.; Beer, R.W.; Malandra, L.J.; Cognevich, M.L.

    1982-01-01

    A quick-acting stud tensioner apparatus for enabling the loosening or tightening of a stud nut on a reactor vessel stud. The apparatus is adapted to engage the vessel stud by closing a gripper around an upper end of the vessel stud when the apparatus is seated on the stud. Upon lifting the apparatus, the gripper releases the vessel stud so that the apparatus can be removed

  9. Unique identification code for medical fundus images using blood vessel pattern for tele-ophthalmology applications.

    Science.gov (United States)

    Singh, Anushikha; Dutta, Malay Kishore; Sharma, Dilip Kumar

    2016-10-01

    Identification of fundus images during transmission and storage in database for tele-ophthalmology applications is an important issue in modern era. The proposed work presents a novel accurate method for generation of unique identification code for identification of fundus images for tele-ophthalmology applications and storage in databases. Unlike existing methods of steganography and watermarking, this method does not tamper the medical image as nothing is embedded in this approach and there is no loss of medical information. Strategic combination of unique blood vessel pattern and patient ID is considered for generation of unique identification code for the digital fundus images. Segmented blood vessel pattern near the optic disc is strategically combined with patient ID for generation of a unique identification code for the image. The proposed method of medical image identification is tested on the publically available DRIVE and MESSIDOR database of fundus image and results are encouraging. Experimental results indicate the uniqueness of identification code and lossless recovery of patient identity from unique identification code for integrity verification of fundus images. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Acidic sweep gas with carbonic anhydrase coated hollow fiber membranes synergistically accelerates CO2 removal from blood.

    Science.gov (United States)

    Arazawa, D T; Kimmel, J D; Finn, M C; Federspiel, W J

    2015-10-01

    The use of extracorporeal carbon dioxide removal (ECCO2R) is well established as a therapy for patients suffering from acute respiratory failure. Development of next generation low blood flow (carbonic anhydrase (CA) immobilized bioactive hollow fiber membrane (HFM) which significantly accelerates CO2 removal from blood in model gas exchange devices by converting bicarbonate to CO2 directly at the HFM surface. This present study tested the hypothesis that dilute sulfur dioxide (SO2) in oxygen sweep gas could further increase CO2 removal by creating an acidic microenvironment within the diffusional boundary layer adjacent to the HFM surface, facilitating dehydration of bicarbonate to CO2. CA was covalently immobilized onto poly (methyl pentene) (PMP) HFMs through glutaraldehyde activated chitosan spacers, potted in model gas exchange devices (0.0151 m(2)) and tested for CO2 removal rate with oxygen (O2) sweep gas and a 2.2% SO2 in oxygen sweep gas mixture. Using pure O2 sweep gas, CA-PMP increased CO2 removal by 31% (258 mL/min/m(2)) compared to PMP (197 mL/min/m(2)) (Premoval by 17% (230 mL/min/m(2)) compared to pure oxygen sweep gas control (Premoval increased by 109% (411 mL/min/m(2)) (Premoval, and when used in combination with bioactive CA-HFMs has a synergistic effect to more than double CO2 removal while maintaining physiologic pH. Through these technologies the next generation of intravascular and paracorporeal respiratory assist devices can remove more CO2 with smaller blood contacting surface areas. A clinical need exists for more efficient respiratory assist devices which utilize low blood flow rates (removal efficiency by shifting equilibrium from bicarbonate to gaseous CO2, through either a bioactive carbonic anhydrase enzyme coating or bulk blood acidification with lactic acid. In this study we demonstrate a novel approach to local blood acidification using an acidified sweep gas in combination with a bioactive coating to more than double CO2 removal

  11. Tests of the geometrical description of blood vessels in a thermal model using counter-current geometries

    NARCIS (Netherlands)

    van Leeuwen, G. M.; Kotte, A. N.; Crezee, J.; Lagendijk, J. J.

    1997-01-01

    We have developed a thermal model, for use in hyperthermia treatment planning, in which blood vessels are described as geometrical objects; 3D curves with associated diameters. For the calculation of the heat exchange with the tissue an analytic result is used. To arrive at this result some

  12. An agent-based model of the response to angioplasty and bare-metal stent deployment in an atherosclerotic blood vessel.

    Directory of Open Access Journals (Sweden)

    Antonia E Curtin

    Full Text Available PURPOSE: While animal models are widely used to investigate the development of restenosis in blood vessels following an intervention, computational models offer another means for investigating this phenomenon. A computational model of the response of a treated vessel would allow investigators to assess the effects of altering certain vessel- and stent-related variables. The authors aimed to develop a novel computational model of restenosis development following an angioplasty and bare-metal stent implantation in an atherosclerotic vessel using agent-based modeling techniques. The presented model is intended to demonstrate the body's response to the intervention and to explore how different vessel geometries or stent arrangements may affect restenosis development. METHODS: The model was created on a two-dimensional grid space. It utilizes the post-procedural vessel lumen diameter and stent information as its input parameters. The simulation starting point of the model is an atherosclerotic vessel after an angioplasty and stent implantation procedure. The model subsequently generates the final lumen diameter, percent change in lumen cross-sectional area, time to lumen diameter stabilization, and local concentrations of inflammatory cytokines upon simulation completion. Simulation results were directly compared with the results from serial imaging studies and cytokine levels studies in atherosclerotic patients from the relevant literature. RESULTS: The final lumen diameter results were all within one standard deviation of the mean lumen diameters reported in the comparison studies. The overlapping-stent simulations yielded results that matched published trends. The cytokine levels remained within the range of physiological levels throughout the simulations. CONCLUSION: We developed a novel computational model that successfully simulated the development of restenosis in a blood vessel following an angioplasty and bare-metal stent deployment based on

  13. Nonparenchymal cells cultivated from explants of fibrotic liver resemble endothelial and smooth muscle cells from blood vessel walls

    International Nuclear Information System (INIS)

    Voss, B.; Rauterberg, J.; Pott, G.; Brehmer, U.; Allam, S.; Lehmann, R.; von Bassewitz, D.B.

    1982-01-01

    Tissue specimens from human fibrotic liver obtained by needle biopsy were cultured. Two cell types emerged from the tissue explants. From their morphology and biosynthetic products they resembled smooth muscle cells and endothelial cells from blood vessel walls. In the endothelial cells, factor VIII-associated protein was demonstrated by indirect immunofluorescence. Synthesis of collagen types I and III, basement membrane collagen types IV and V, and fibronectin by both cell types was observed by immunofluorescence microscopy. Homogeneous cultures of smooth muscle cells were observed in subcultures. After incubation with [ 14 C]glycine, collagen was isolated and characterized by CM cellulose chromatography, and consisted mainly of types I and III. These data suggest involvement of mesenchymal cells in hepatic fibrosis; they presumably originate from blood vessel or sinusoidal walls

  14. Comprehending the structure of a vacuum vessel and in-vessel components of fusion machines. 1. Comprehending the vacuum vessel structure

    International Nuclear Information System (INIS)

    Onozuka, Masanori; Nakahira, Masataka

    2006-01-01

    The functions, conditions and structure of vacuum vessel using tokamak fusion machines are explained. The structural standard and code of vacuum vessel, process of vacuum vessel design, and design of ITER vacuum vessel are described. Production and maintenance of ultra high vacuum, confinement of radioactive materials, support of machines in vessel and electromagnetic force, radiation shield, plasma vertical stability, one-turn electric resistance, high temperature baking heat and remove of nuclear heat, reduce of troidal ripple, structural standard, features of safety of nuclear fusion machines, subjects of structural standard of fusion vacuum vessel, design flow of vacuum vessel, establishment of radial build, selections of materials, baking and cooling method, basic structure, structure of special parts, shield structure, and of support structure, and example of design of structure, ITER, are stated. (S.Y.)

  15. Effects of x rays on the morphology and physiology of the CNS blood vessels of mice

    Energy Technology Data Exchange (ETDEWEB)

    Gladysz, J [Akademia Medyczna, Poznan (Poland)

    1974-01-01

    Irradiation of the CNS of mice with 4000 to 7600 R produces transitional disorder of the permeability of vascular walls, followed by a permanent (irreversible) degenerative lesion of blood capillaries and the surrounding astrogial cells. Intensity of this alterations may however not be the same in different terminal blood vessels. It is very likely that the above described lesion appearing in the acute phase can be the main cause of further alterations in the CNS which are observed in late phase of postradiation disease.

  16. Blood Vessel Enhancement and Segmentation for Screening of Diabetic Retinopathy

    Directory of Open Access Journals (Sweden)

    Ibaa Jamal

    2012-06-01

    Full Text Available Diabetic retinopathy is an eye disease caused by the increase of insulin in blood and it is one of the main cuases of blindness in idusterlized countries. It is a progressive disease and needs an early detection and treatment. Vascular pattern of human retina helps the ophthalmologists in automated screening and diagnosis of diabetic retinopathy. In this article, we present a method for vascular pattern ehnacement and segmentation. We present an automated system which uses wavelets to enhance the vascular pattern and then it applies a piecewise threshold probing and adaptive thresholding for vessel localization and segmentation respectively. The method is evaluated and tested using publicly available retinal databases and we further compare our method with already proposed techniques.

  17. Blood vessels segmentation of hatching eggs based on fully convolutional networks

    Science.gov (United States)

    Geng, Lei; Qiu, Ling; Wu, Jun; Xiao, Zhitao

    2018-04-01

    FCN, trained end-to-end, pixels-to-pixels, predict result of each pixel. It has been widely used for semantic segmentation. In order to realize the blood vessels segmentation of hatching eggs, a method based on FCN is proposed in this paper. The training datasets are composed of patches extracted from very few images to augment data. The network combines with lower layer and deconvolution to enables precise segmentation. The proposed method frees from the problem that training deep networks need large scale samples. Experimental results on hatching eggs demonstrate that this method can yield more accurate segmentation outputs than previous researches. It provides a convenient reference for fertility detection subsequently.

  18. An Original Approach for Quantification of Blood Vessels on the Whole Tumour Section

    Directory of Open Access Journals (Sweden)

    Nga Tran Kim

    2003-01-01

    Full Text Available Relative abundance of tumour angiogenesis has been shown to be of clinical relevance in cancers of various locations such as the ovary. Nevertheless, several problems are encountered when quantifying tumour microvessels: (i as many other tumour markers, vascularity pattern is often heterogeneous within the tumour mass and even within the same histological section. As a consequence, an adequate acquisition method must be developed for accurate field sampling. (ii Manual microvessel counting is long, tedious and subject to poor reproducibility. Introduction in routine practice requires a fast, reproducible and reliable automatic image processing. In this study we present an original procedure combining a slide scanner image acquisition and a fully automatic image analysis sequence. The slide scanner offers the advantage of recording an image of the whole histological section for subsequent automatic blood vessel detection and hot spot area location. Microvessel density and surface fraction were measured for the whole section as well as within hot spots. Different immunostaining methods were tested in order to optimise the procedure. Moreover, the method proposed was submitted to a quality control procedure, with reference to interactive identification of microvessels at scanner level. This experiment showed that 93 to 97% of blood vessels were detected, according to the staining protocol used. Colour figures can be viewed on http://www.esacp.org/acp/2003/25‐2/kim.htm.

  19. Spent nuclear fuel assembly storage vessel

    International Nuclear Information System (INIS)

    Yagishita, Takuya

    1998-01-01

    The vessel of the present invention promotes an effect of removing after heat of spent nuclear fuel assemblies so as not to give force to the storage vessel caused by expansion of heat removing partitioning plates. Namely, the vessel of the present invention comprises a cylinder body having closed upper and lower portions and a plurality of heat removing partitioning cylinders disposed each at a predetermined interval in the circumferential direction of the above-mentioned cylinder body. The heat removing partitioning cylinders comprises (1) first heat removing partitioning plates extended in the radial direction of the cylinder body and opposed at a predetermined gap in the circumferential direction of the cylinder body, and having the base ends on the side of the inner wall of the cylinder body being secured to the inner wall of the cylinder body and (2) a second heat removing plate for connecting the top ends of both opposed heat removing partitioning plates on the central side of the cylinder body with each other. Spent nuclear fuel assemblies are contained in a plurality of closed spaces surrounded by the first heat removing partitioning plates and the second heat removing partitioning plate. With such constitution, since after heat is partially transferred from the heat removing partitioning plates to the cylindrical body directly by heat conduction, the heat removing effect can be promoted compared with the prior art. (I.S.)

  20. Morphological evaluation of the cerebral blood vessels in the late gestation fetal sheep following hypoxia in utero.

    Science.gov (United States)

    Baburamani, Ana A; Lo, Camden; Castillo-Melendez, Margie; Walker, David W

    2013-01-01

    Hypoxia can significantly contribute to the development of permanent brain injury in the term neonate; however the response of cerebral blood vessels is not well understood. This study aimed to quantitatively measure vascular density and morphology using laminin immunohistochemistry as a marker of blood vessels, and determine the effects of a single, severe bout of hypoxia (umbilical cord occlusion, UCO) late in gestation on the developing cerebrovasculature in fetal sheep. At 124-126 days gestation singleton fetal sheep underwent surgery for implantation of catheters and placement of an inflatable cuff around the umbilical cord. A 10 min UCO or sham UCO (n=5) occurred at 132 days gestation. Fetal brains were collected at 24 h (n=5) or 48 h (n=4) after UCO for vascular density and morphology analysis of laminin immunohistochemistry. 48 h following a single, brief bout of severe hypoxia late in gestation decreased vascular density was seen in the caudate nucleus and no changes in vascular morphology occurred. However closer analysis revealed a significant shift in the frequency of smaller (≤10 μm) to larger (≤100 μm) perimeter blood vessels in periventricular and subcortical white matter. Close examination of the frequency distribution of vascular perimeter highlights that alterations in vascular morphology persist in the near term fetal brain for up to 48 h following a brief (10 min) hypoxia in white but not gray matter. These findings suggest that the near term brain may still be vulnerable to white matter injury following in utero hypoxia. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Disrupting established tumor blood vessels: an emerging therapeutic strategy for cancer.

    Science.gov (United States)

    McKeage, Mark J; Baguley, Bruce C

    2010-04-15

    The unique characteristics of tumor vasculature represent an attractive target that may be exploited by vascular-targeting anticancer agents. A promising strategy involves the selective disruption of established tumor blood vessels by tumor-vascular disrupting agents (tumor-VDAs), which exhibit antivascular activity, resulting in inhibition of tumor blood flow and extensive necrosis within the tumor core. The tumor-VDA class can be subdivided into flavonoid compounds, which are related to flavone acetic acid, and tubulin-binding compounds. ASA404, of the flavonoid class, is the most advanced tumor-VDA in clinical development and has been evaluated preclinically and in several phase 1 and phase 2 studies. Preclinical studies have demonstrated the selective apoptosis of tumor endothelial cells and the inhibition of tumor blood flow. Synergistic activity was observed with ASA404 and with several chemotherapeutic agents, particularly taxanes. In clinical trials, compared with chemotherapy alone, ASA404 was tolerated well and produced improved activity in patients with nonsmall cell lung cancer when combined with paclitaxel and carboplatin. Phase 3 clinical trials are ongoing. Selectively targeting established tumor vasculature with tumor-VDAs represents a promising and innovative approach to improving the efficacy of standard anticancer therapies. (c) 2010 American Cancer Society.

  2. The comparison of placental removal methods on operative blood loss

    International Nuclear Information System (INIS)

    Waqar, F.; Fawad, A.

    2008-01-01

    On an average 1 litre of blood is lost during Caesarean Section. Many variable techniques have been tried to reduce this blood loss. Many study trials have shown the spontaneous delivery of placenta method to be superior over manual method because of reduced intra operative blood loss and reduced incidence of post operative endometritis. The main objective of our study was to compare the risk of blood loss associated with spontaneous and manual removal of the placenta during caesarean section. This study was conducted at Department of Obstetrics and Gynaecology, Islamic International Medical Complex, Islamabad from September 2004 to September 2005. All Women undergoing elective or emergency caesarean section were included in the study. Exclusion criteria were pregnancy below 37 weeks, severe maternal anaemia, and prolonged rupture of the membranes with fever, placenta praevia, placenta accreta and clotting disorders. Patients were allocated to the two groups randomly. Group A comprised of women in whom the obstetrician waited a maximum of 5 minutes till the placenta delivered spontaneously. In group B the obstetrician manually cleaved out the placenta as soon as the infant was delivered. The primary outcome measures noted were difference in haemoglobin of >2 gm/dl (preoperatively and postoperatively), time interval between delivery of baby and placenta, significant blood loss (>1000 cc), additional use of oxytocics, total operating time and blood transfusions. Data was analysed by SPSS. Statistical tests used for specific comparison were chi square-test and Student's t-test. One hundred and forty-five patients were allocated to two groups randomly. Seventy-eight patients were allocated to group A and 67 patients allocated to group B. Mean maternal age, birth weight, and total operating time were the same in two groups, but blood loss as measured by a difference in haemoglobin of greater then 2 grams/dl was statistically significant. Significant blood loss (>1000 cc

  3. Study of blood flow inside the stenosis vessel under the effect of solenoid magnetic field using ferrohydrodynamics principles

    Science.gov (United States)

    Badfar, Homayoun; Motlagh, Saber Yekani; Sharifi, Abbas

    2017-10-01

    In this paper, biomagnetic blood flow in the stenosis vessel under the effect of the solenoid magnetic field is studied using the ferrohydrodynamics (FHD) model. The parabolic profile is considered at an inlet of the axisymmetric stenosis vessel. Blood is modeled as electrically non-conducting, Newtonian and homogeneous fluid. Finite volume and the SIMPLE (Semi-Implicit Method for Pressure Linked Equations) algorithm are utilized to discretize governing equations. The investigation is studied at different magnetic numbers ( MnF=164, 328, 1640 and 3280) and the number of the coil loops (three, five and nine loops). Results indicate an increase in heat transfer, wall shear stress and energy loss (pressure drop) with an increment in the magnetic number (ratio of Kelvin force to dynamic pressure force), arising from the FHD, and the number of solenoid loops. Furthermore, the flow pattern is affected by the magnetic field, and the temperature of blood can be decreased up to 1.48 {}°C under the effect of the solenoid magnetic field with nine loops and reference magnetic field ( B0) of 2 tesla.

  4. Evidence of Flicker-Induced Functional Hyperaemia in the Smallest Vessels of the Human Retinal Blood Supply.

    Directory of Open Access Journals (Sweden)

    Angelina Duan

    Full Text Available Regional changes in blood flow are initiated within neural tissue to help fuel local differences in neural activity. Classically, this response was thought to arise only in larger arterioles and venules. However, recently, it has been proposed that a the smallest vessels of the circulation make a comparable contribution, and b the response should be localised intermittently along such vessels, due to the known distribution of contractile mural cells. To assess these hypotheses in human neural tissue in vivo, we imaged the retinal microvasculature (diameters 3-28 μm non-invasively, using adaptive optics, before and after delivery of focal (360 μm patches of flickering visible light. Our results demonstrated a definite average response in 35% of all vessel segments analysed. In these responding vessels, the magnitude of proportional dilation (mean ± SEM for pre-capillary arterioles 13 ± 5%, capillaries 31 ± 8%, and post-capillary venules 10 ± 3% is generally far greater than the magnitudes we and others have measured in the larger retinal vessels, supporting proposition a above. The dilations observed in venules were unexpected based on previous animal work, and may be attributed either to differences in stimulus or species. Response heterogeneity across the network was high; responses were also heterogeneous along individual vessels (45% of vessel segments showed demonstrable locality in their response. These observations support proposition b above. We also observed a definite average constriction across 7% of vessel segments (mean ± SEM constriction for capillaries -16 ± 3.2%, and post-capillary venules -18 ± 12%, which paints a picture of dynamic redistribution of flow throughout the smallest vessel networks in the retina in response to local, stimulus-driven metabolic demand.

  5. Method for temporary shielding of reactor vessel internals

    International Nuclear Information System (INIS)

    Grimm, N.P.; Sejvar, J.

    1991-01-01

    This patent describes a method for shielding stored internals for reactor vessel annealing. It comprises removing nuclear fuel from the reactor vessel containment building; removing and storing upper and lower core internals under water in a refueling canal storage area; assembling a support structure in the refueling canal between the reactor vessel and the stored internals; introducing vertical shielding tanks individually through a hatch in the containment building and positioning each into the support structure; introducing horizontal shielding tanks individually through a hatch in the containment building and positioning each above the stored internals and vertical tanks; draining water from the refueling canal to the level of a flange of the reactor vessel; placing an annealing apparatus in the reactor vessel; pumping the remaining water from the reactor vessel; and annealing the reactor vessel

  6. Investigation of vessel exterior air cooling for a HLMC reactor

    International Nuclear Information System (INIS)

    Sienicki, J. J.; Spencer, B. W.

    2000-01-01

    The Secure Transportable Autonomous Reactor (STAR) concept under development at Argonne National Laboratory provides a small (300 MWt) reactor module for steam supply that incorporates design features to attain proliferation resistance, heightened passive safety, and improved cost competitiveness through extreme simplification. Examples are the achievement of 100%+ natural circulation heat removal from the low power density/low pressure drop ultra-long lifetime core and utilization of lead-bismuth eutectic (LBE) coolant enabling elimination of main coolant pumps as well as the need for an intermediate heat transport circuit. It is required to provide a passive means of removing decay heat and effecting reactor cooldown in the event that the normal steam generator heat sink, including its normal shutdown heat removal mode, is postulated to be unavailable. In the present approach, denoted as the Reactor Exterior Cooling System (RECS), passive decay heat removal is provided by cooling the outside of the containment/guard vessel with air. RECS is similar to the Reactor Vessel Auxiliary Cooling System (RVACS) incorporated into the PRISM design. However, to enhance the heat removal, RECS incorporates fins on the containment vessel exterior to enhance heat transfer to air as well as removable steel venetian conductors that provide a conduction heat transfer path across the reactor vessel-containment vessel gap to enhance heat transfer between the vessels. The objective of the present work is to investigate the effectiveness of air cooling in removing heat from the vessel and limiting the coolant temperature increase following a sudden complete loss of the steam generator heat sink

  7. An automated vessel segmentation of retinal images using multiscale vesselness

    International Nuclear Information System (INIS)

    Ben Abdallah, M.; Malek, J.; Tourki, R.; Krissian, K.

    2011-01-01

    The ocular fundus image can provide information on pathological changes caused by local ocular diseases and early signs of certain systemic diseases, such as diabetes and hypertension. Automated analysis and interpretation of fundus images has become a necessary and important diagnostic procedure in ophthalmology. The extraction of blood vessels from retinal images is an important and challenging task in medical analysis and diagnosis. In this paper, we introduce an implementation of the anisotropic diffusion which allows reducing the noise and better preserving small structures like vessels in 2D images. A vessel detection filter, based on a multi-scale vesselness function, is then applied to enhance vascular structures.

  8. Distribution of Vascular Patterns in Different Subtypes of Renal Cell Carcinoma. A Morphometric Study in Two Distinct Types of Blood Vessels.

    Science.gov (United States)

    Ruiz-Saurí, Amparo; García-Bustos, V; Granero, E; Cuesta, S; Sales, M A; Marcos, V; Llombart-Bosch, A

    2017-07-01

    To analyze the presence of mature and immature vessels as a prognostic factor in patients with renal cell carcinoma and propose a classification of renal cancer tumor blood vessels according to morphometric parameters. Tissue samples were obtained from 121 renal cell carcinoma patients who underwent radical nephrectomy. Staining with CD31 and CD34 was used to differentiate between immature (CD31+) and mature (CD34+) blood vessels. We quantified the microvascular density, microvascular area and different morphometric parameters: maximum diameter, minimum diameter, major axis, minor axis, perimeter, radius ratio and roundness. We found that the microvascular density was higher in CD31+ than CD34+ vessels, but CD34+ vessels were larger than CD31+ vessels, as well as being strongly correlated with the ISUP tumor grade. We also identified four vascular patterns: pseudoacinar, fascicular, reticular and diffuse. Pseudoacinar and fascicular patterns were more frequent in clear cell renal cell carcinoma (37.62 and 35.64% respectively), followed by reticular pattern (21.78%), while in chromophobe tumors the reticular pattern predominated (90%). The isolated pattern was present in all papillary tumors (100%). In healthy renal tissue, the pseudoacinar and isolated patterns were differentially found in the renal cortex and medulla respectively. We defined four distinct vascular patterns significantly related with the ISUP tumor grade in renal cell carcinomas. Further studies in larger series are needed in order to validate these results. Analysis of both mature and immature vessels (CD34+ and CD31+) provides additional information when evaluating microvascular density.

  9. Blood Pressure Control in Aging Predicts Cerebral Atrophy Related to Small-Vessel White Matter Lesions

    Directory of Open Access Journals (Sweden)

    Kyle C. Kern

    2017-05-01

    Full Text Available Cerebral small-vessel damage manifests as white matter hyperintensities and cerebral atrophy on brain MRI and is associated with aging, cognitive decline and dementia. We sought to examine the interrelationship of these imaging biomarkers and the influence of hypertension in older individuals. We used a multivariate spatial covariance neuroimaging technique to localize the effects of white matter lesion load on regional gray matter volume and assessed the role of blood pressure control, age and education on this relationship. Using a case-control design matching for age, gender, and educational attainment we selected 64 participants with normal blood pressure, controlled hypertension or uncontrolled hypertension from the Northern Manhattan Study cohort. We applied gray matter voxel-based morphometry with the scaled subprofile model to (1 identify regional covariance patterns of gray matter volume differences associated with white matter lesion load, (2 compare this relationship across blood pressure groups, and (3 relate it to cognitive performance. In this group of participants aged 60–86 years, we identified a pattern of reduced gray matter volume associated with white matter lesion load in bilateral temporal-parietal regions with relative preservation of volume in the basal forebrain, thalami and cingulate cortex. This pattern was expressed most in the uncontrolled hypertension group and least in the normotensives, but was also more evident in older and more educated individuals. Expression of this pattern was associated with worse performance in executive function and memory. In summary, white matter lesions from small-vessel disease are associated with a regional pattern of gray matter atrophy that is mitigated by blood pressure control, exacerbated by aging, and associated with cognitive performance.

  10. Changes in peripapillary blood vessel density in Graves' orbitopathy after orbital decompression surgery as measured by optical coherence tomography angiography.

    Science.gov (United States)

    Lewis, Kyle T; Bullock, John R; Drumright, Ryan T; Olsen, Matthew J; Penman, Alan D

    2018-03-08

    The purpose is to evaluate the utility of optical coherence tomography (OCT) angiography in the evaluation of Graves' orbitopathy (GO) and response to orbital decompression in patients with and without dysthyroid optic neuropathy (DON). This was a single-center, prospective case series in a cohort of 12 patients (24 orbits) with GO and ±DON, (6 orbits) who underwent bilateral orbital decompression. All patients underwent pre- and postoperative OCT angiography of the peripapillary area. Vessel density indices were calculated in a 4.5 mm × 4.5 mm ellipsoid centered on the optic disk using split-spectrum amplitude decorrelation angiography algorithm, producing the vessel density measurements. Mean change in vessel density indices was compared between pre- and postoperative sessions and between patients with and without DON. Patient 1, a 34-year-old male with GO and unilateral DON OD, showed a significant reduction in blood vessel density indices oculus dexter (OD) (DON eye) after decompression while a more modest reduction was found oculus sinister (OS) with the greatest change noted intrapapillary. Patient 2, a 50-year-old male with DON OU, showed worsening neuropathy following decompression OD that was confirmed by angiographic density indices. Patient 3, a 55-year-female with DON, showed a reduction in blood vessel density OD and increased density OS. Patients without DON showed overall less impressive changes in indices as compared to those with DON. Using OCT angiography, response to surgical treatment in GO orbits, more so in orbits with DON, can be demonstrated and quantified using vessel density indices with reproducibility.

  11. Ultrastructural analysis of small blood vessels in skin biopsies in CADASIL

    Directory of Open Access Journals (Sweden)

    Lačković Vesna

    2008-01-01

    Full Text Available Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL is an inherited small- and medium-artery disease of the brain caused by mutation of the Notch3 gene. Very often, this disease is misdiagnosed. We examined skin biopsies in two members of the first discovered Serbian family affected by CADASIL. Electron microscopy showed that skin blood vessels of both patients contain numerous deposits of granular osmiophilic material (GOM around vascular smooth muscle cells (VSMCs. We observed degeneration of VSMCs, reorganization of their cytoskeleton and dense bodies, disruption of myoendothelial contacts, and apoptosis. Our results suggest that the presence of GOM in small skin arteries represents a specific marker in diagnosis of CADASIL.

  12. Chronic hydrocephalus-induced hypoxia: increased expression of VEGFR-2+ and blood vessel density in hippocampus.

    Science.gov (United States)

    Dombrowski, S M; Deshpande, A; Dingwall, C; Leichliter, A; Leibson, Z; Luciano, M G

    2008-03-18

    Chronic hydrocephalus (CH) is a neurological disease characterized by increased cerebrospinal fluid volume and pressure that is often associated with impaired cognitive function. By and large, CH is a complex and heterogeneous cerebrospinal fluid (CSF) disorder where the exact site of brain insult is uncertain. Several mechanisms including neural compression, fiber stretch, and local or global hypoxia have been implicated in the underlying pathophysiology of CH. Specifically, the hippocampus, which plays a significant role in memory processing and is in direct contact with expanding CSF ventricles, may be involved. Using our model of chronic hydrocephalus, we quantified the density of vascular endothelial growth factor receptor 2 (VEGFR-2(+)) neurons, glial, endothelial cells, and blood vessels in hippocampal regions CA1, CA2-3, dentate gyrus and hilus using immunohistochemical and stereological methods. Density and %VEGFR-2(+) cell populations were estimated for CH animals (2-3 weeks vs. 12-16 weeks) and surgical controls (SC). Overall, we found approximately six- to eightfold increase in the cellular density of VEGFR-2(+) and more than double blood vessel density (BVd) in the hippocampus of CH compared with SC. There were no significant regional differences in VEGFR-2(+) cellular and BVd expression in the CH group. VEGFR-2(+) and BVds were significantly related to changes in CSF volume (Pblood vessel expression was related to focal compression alone or in combination with global ischemia/hypoxia conditions as previously described. These findings suggest that VEGFR-2 may play an adaptive role in angiogenesis after CH

  13. How to replace a reactor pressure vessel

    International Nuclear Information System (INIS)

    Huber, R.

    1996-01-01

    A potential life extending procedure for a nuclear reactor after, say, 40 years of service life, might in some circumstances be the replacement of the reactor pressure vessel. Neutron induced degradation of the vessel might make replacement by one of a different material composition desirable, for example. Although the replacement of heavy components, such as steam generators, has been possible for many years, the pressure vessel presents a much more demanding task if only because it is highly irradiated. Some preliminary feasibility studies by Siemens are reported for the two removal strategies that might be considered. These are removal of the entire pressure vessel in one piece and dismantling it into sections. (UK)

  14. Manipulator arm for a nuclear reactor vessel inspection device

    International Nuclear Information System (INIS)

    1980-01-01

    A manipulator arm for a reactor vessel in-service inspection apparatus is adapted to transport a transducer array for ultrasonic examination of welds at any point in the vessel. The removal of the inspection device from the reactor vessel in an emergency presents a problem where a relatively long manipulator arm is used. This invention provides an improved arm with means for changing the normal orientation of the arm to a shorter one to permit safe removal of the inspection device from the reactor vessel. (author)

  15. Micropatterned coculture of vascular endothelial and smooth muscle cells on layered electrospun fibrous mats toward blood vessel engineering.

    Science.gov (United States)

    Li, Huinan; Liu, Yaowen; Lu, Jinfu; Wei, Jiaojun; Li, Xiaohong

    2015-06-01

    A major challenge in vascular engineering is the establishment of proper microenvironment to guide the spatial organization, growth, and extracellular matrix (ECM) productions of cells found in blood vessels. In the current study, micropatterned fibrous mats with distinct ridges and grooves of different width were created to load smooth muscle cells (SMCs), which were assembled by stacking on vascular endothelial cell (EC)-loaded flat fibrous mats to mimic the in vivo-like organized structure of blood vessels. SMCs were mainly distributed in the ridges, and aligned fibers in the patterned regions led to the formation of elongated cell bodies, intense actin filaments, and expressions of collagen I and α-smooth muscle actin in a parallel direction with fibers. ECs spread over the flat fibrous mats and expressed collagen IV and laminin with a cobblestone-like feature. A z-stack scanning of fluorescently stained fibrous mats indicated that SMCs effectively infiltrated into fibrous scaffolds at the depth of around 200 μm. Compared with SMCs cultured alone, the coculture with ECs enhanced the proliferation, infiltration, and cytoskeleton elongation of SMCs on patterned fibrous mats. Although the coculture of SMCs made no significant difference in the EC growth, the coculture system on patterned fibrous scaffolds promoted ECM productions of both ECs and SMCs. Thus, this patterned fibrous configuration not only offers a promising technology in the design of tissue engineering scaffolds to construct blood vessels with durable mechanical properties, but also provides a platform for patterned coculture to investigate cell-matrix and cell-cell interactions in highly organized tissues. © 2014 Wiley Periodicals, Inc.

  16. Removal of cellular-type hemoglobin-based oxygen carrier (hemoglobin-vesicles) from blood using centrifugation and ultrafiltration.

    Science.gov (United States)

    Sakai, Hiromi; Sou, Keitaro; Horinouchi, Hirohisa; Tsuchida, Eishun; Kobayashi, Koichi

    2012-02-01

    The hemoglobin-vesicle (HbV) is an artificial oxygen carrier encapsulating a concentrated hemoglobin solution in a phospholipid vesicle (liposome). During or after transporting oxygen, macrophages capture HbVs in the reticuloendothelial system (RES) with an approximate circulation half-life of 3 days. Animal studies show transient splenohepatomegaly after large doses, but HbVs were completely degraded, and the components were excreted in a few weeks. If a blood substitute is used for emergency use until red blood cell transfusion becomes available or for temporary use such as a priming fluid for an extracorporeal circuit, then one option would be to remove HbVs from the circulating blood without waiting a few weeks for removal by the RES. Using a mixture of beagle dog whole blood and HbV, we tested the separation of HbV using a centrifugal Fresenius cell separator and an ultrafiltration system. The cell separator system separated the layers of blood cell components from the HbV-containing plasma layer by centrifugal force, and then the HbV was removed from plasma phase by the ultrafiltration system. The HbVs (250-280 nm) are larger than plasma proteins (blood cell components (> 3 µm). The size of HbVs is advantageous to be separated from the original blood components, and the separated blood components can be returned to circulation. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  17. Treatment of hepatocellular carcinoma adjacent to large blood vessels using 1.5T MRI-guided percutaneous radiofrequency ablation combined with iodine-125 radioactive seed implantation

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Zheng-Yu, E-mail: linsinlan@yahoo.com.cn [The Department of Radiology, First Affiliated Hospital of Fujian Medical University, 20 Chazhong Road, Fuzhou 350005 (China); Chen, Jin, E-mail: snow8968851@163.com [The Department of Radiology, First Affiliated Hospital of Fujian Medical University, 20 Chazhong Road, Fuzhou 350005 (China); Deng, Xiu-Fen, E-mail: dxf197286@yahoo.com.cn [The Department of Radiology, First Affiliated Hospital of Fujian Medical University, 20 Chazhong Road, Fuzhou 350005 (China)

    2012-11-15

    Objective: The objective is to study the technology associated with and feasibility of the treatment of hepatocellular carcinoma (HCC) adjacent to large blood vessels using 1.5T MRI-guided radiofrequency ablation combined with iodine-125 (I-125) radioactive seed implantation. Methods: Sixteen patients with a total of 24 HCC lesions (average maximum diameter: 2.35 {+-} 1.03 cm) were pathologically confirmed by biopsy or clinically diagnosed received 1.5T MRI-guided percutaneous radiofrequency ablation (RFA) treatment. Each patient had one lesion adjacent to large blood vessels ({>=}3 mm); after the ablation, I-125 radioactive seeds were implanted in the portions of the lesions that were adjacent to the blood vessels. Results: All the ablations and I-125 radioactive seed implantations were successful; a total of 118 seeds were implanted. The ablated lesions exhibited hypointense signals on the T2WI sequence with a thin rim of hyperintense signals; they also exhibited significant hyperintense signals on the T1WI sequence with clear boundaries. The average follow-up period was 11.1 {+-} 6.2 months. There were 23 complete responses and one partial response in the 24 lesions. The alpha-fetoprotein (AFP) levels of the patients significantly decreased. Conclusion: The 1.5T MRI-guided RFA combined with I-125 radioactive seed implantation for the treatment of HCC adjacent to large blood vessels is an effective technology.

  18. Effect of antiprogesterone RU486 on VEGF expression and blood vessel remodeling on ovarian follicles before ovulation.

    Directory of Open Access Journals (Sweden)

    Annunziata Mauro

    Full Text Available BACKGROUND: The success of ovarian follicle growth and ovulation is strictly related to the development of an adequate blood vessel network required to sustain the proliferative and endocrine functions of the follicular cells. Even if the Vascular Endothelial Growth Factor (VEGF drives angiogenesis before ovulation, the local role exerted by Progesterone (P₄ remains to be clarified, in particular when its concentration rapidly increases before ovulation. AIM: This in vivo study was designed to clarify the effect promoted by a P₄ receptor antagonist, RU486, on VEGF expression and follicular angiogenesis before ovulation, in particular, during the transition from pre to periovulatory follicles induced by human Chorionic Gonadotropins (hCG administration. MATERIAL AND METHODS: Preovulatory follicle growth and ovulation were pharmacologically induced in prepubertal gilts by combining equine Chorionic Gonadotropins (eCG and hCG used in the presence or absence of RU486. The effects on VEGF expression were analyzed using biochemical and immunohistochemical studies, either on granulosa or on theca layers of follicles isolated few hours before ovulation. This angiogenic factor was also correlated to follicular morphology and to blood vessels architecture. RESULTS AND CONCLUSIONS: VEGF production, blood vessel network and follicle remodeling were impaired by RU486 treatment, even if the cause-effect correlation remains to be clarified. The P₄ antagonist strongly down-regulated theca VEGF expression, thus, preventing most of the angiogenic follicle response induced by hCG. RU486-treated follicles displayed a reduced vascular area, a lower rate of endothelial cell proliferation and a reduced recruitment of perivascular mural cells. These data provide important insights on the biological role of RU486 and, indirectly, on steroid hormones during periovulatory follicular phase. In addition, an in vivo model is proposed to evaluate how periovulatory

  19. Blood vessel endothelium-directed tumor cell streaming in breast tumors requires the HGF/C-Met signaling pathway.

    Science.gov (United States)

    Leung, E; Xue, A; Wang, Y; Rougerie, P; Sharma, V P; Eddy, R; Cox, D; Condeelis, J

    2017-05-11

    During metastasis to distant sites, tumor cells migrate to blood vessels. In vivo, breast tumor cells utilize a specialized mode of migration known as streaming, where a linear assembly of tumor cells migrate directionally towards blood vessels on fibronectin-collagen I-containing extracellular matrix (ECM) fibers in response to chemotactic signals. We have successfully reconstructed tumor cell streaming in vitro by co-plating tumors cells, macrophages and endothelial cells on 2.5 μm thick ECM-coated micro-patterned substrates. We found that tumor cells and macrophages, when plated together on the micro-patterned substrates, do not demonstrate sustained directional migration in only one direction (sustained directionality) but show random bi-directional walking. Sustained directionality of tumor cells as seen in vivo was established in vitro when beads coated with human umbilical vein endothelial cells were placed at one end of the micro-patterned 'ECM fibers' within the assay. We demonstrated that these endothelial cells supply the hepatocyte growth factor (HGF) required for the chemotactic gradient responsible for sustained directionality. Using this in vitro reconstituted streaming system, we found that directional streaming is dependent on, and most effectively blocked, by inhibiting the HGF/C-Met signaling pathway between endothelial cells and tumor cells. Key observations made with the in vitro reconstituted system implicating C-Met signaling were confirmed in vivo in mammary tumors using the in vivo invasion assay and intravital multiphoton imaging of tumor cell streaming. These results establish HGF/C-Met as a central organizing signal in blood vessel-directed tumor cell migration in vivo and highlight a promising role for C-Met inhibitors in blocking tumor cell streaming and metastasis in vivo, and for use in human trials.

  20. FFTF and CRBRP reactor vessels

    International Nuclear Information System (INIS)

    Morgan, R.E.

    1977-01-01

    The Fast Flux Test Facility (FFTF) reactor vessel and the Clinch River Breeder Reactor Plant (CRBRP) reactor vessel each serve to enclose a fast spectrum reactor core, contain the sodium coolant, and provide support and positioning for the closure head and internal structure. Each vessel is located in its reactor cavity and is protected by a guard vessel which would ensure continued decay heat removal capability should a major system leak develop. Although the two plants have significantly different thermal power ratings, 400 megawatts for FFTF and 975 megawatts for CRBRP, the two reactor vessels are comparable in size, the CRBRP vessel being approximately 28% longer than the FFTF vessel. The FFTF vessel diameter was controlled by the space required for the three individual In-Vessel Handling Machines and Instrument Trees. Utilization of the triple rotating plug scheme for CRBRP refueling enables packaging of the larger CRBRP core in a vessel the same diameter as the FFTF vessel

  1. Blood vessel-based liver segmentation through the portal phase of a CT dataset

    Science.gov (United States)

    Maklad, Ahmed S.; Matsuhiro, Mikio; Suzuki, Hidenobu; Kawata, Yoshiki; Niki, Noboru; Moriyama, Noriyuki; Utsunomiya, Toru; Shimada, Mitsuo

    2013-02-01

    Blood vessels are dispersed throughout the human body organs and carry unique information for each person. This information can be used to delineate organ boundaries. The proposed method relies on abdominal blood vessels (ABV) to segment the liver considering the potential presence of tumors through the portal phase of a CT dataset. ABV are extracted and classified into hepatic (HBV) and nonhepatic (non-HBV) with a small number of interactions. HBV and non-HBV are used to guide an automatic segmentation of the liver. HBV are used to individually segment the core region of the liver. This region and non-HBV are used to construct a boundary surface between the liver and other organs to separate them. The core region is classified based on extracted posterior distributions of its histogram into low intensity tumor (LIT) and non-LIT core regions. Non-LIT case includes normal part of liver, HBV, and high intensity tumors if exist. Each core region is extended based on its corresponding posterior distribution. Extension is completed when it reaches either a variation in intensity or the constructed boundary surface. The method was applied to 80 datasets (30 Medical Image Computing and Computer Assisted Intervention (MICCAI) and 50 non-MICCAI data) including 60 datasets with tumors. Our results for the MICCAI-test data were evaluated by sliver07 [1] with an overall score of 79.7, which ranks seventh best on the site (December 2013). This approach seems a promising method for extraction of liver volumetry of various shapes and sizes and low intensity hepatic tumors.

  2. Design and development of a blood vessel localization system using a Nir viewer

    International Nuclear Information System (INIS)

    Hernandez R, A.; Plascencia C, L. E.; Cordova F, T.; Padilla R, N.

    2017-10-01

    In addition to the multiple applications of ionizing radiation in clinical diagnosis there is the possibility of using another part of the electromagnetic spectrum such as near infrared (Nir). This paper presents the design and construction of a Nir Biosensor in a range between 800 and 900 nm, which allows the visualization of blood vessels for the venepuncture procedure with the aim of reducing the trauma of venous access to patients of all ages. The possibility that the device is used in the location of venous ulcers as an alternative to veno grams obtained by X-rays is also explored. (Author)

  3. Remote non-invasive stereoscopic imaging of blood vessels: first in-vivo results of a new multispectral contrast enhancement technology

    NARCIS (Netherlands)

    Wieringa, F.P.; Mastik, F.; Cate, F.J. ten; Neumann, H.A.M.; Steen, A.F.W. van der

    2006-01-01

    We describe a contactless optical technique selectively enhancing superficial blood vessels below variously pigmented intact human skin by combining images in different spectral bands. Two CMOS-cameras, with apochromatic lenses and dual-band LED-arrays, simultaneously streamed Left (L) and Right (R)

  4. 3-D MDT with spherical targets by bilinear interpolation for determining blood velocity profiles including the vessel wall effect

    Science.gov (United States)

    Choomphon-anomakhun, Natthaphon; Natenapit, Mayuree

    2018-02-01

    A numerical simulation of three-dimensional (3-D) implant assisted-magnetic drug targeting (IA-MDT) using ferromagnetic spherical targets, including the effect from the vessel wall on the blood flow, is presented. The targets were implanted within arterioles and subjected to an externally uniform applied magnetic field in order to increase the effectiveness of targeting magnetic drug carrier particles (MDCPs). The capture area (As) of the MDCPs was determined by inspection of the particle trajectories simulated from the particle equations of motion. The blood flow velocities at any particle position around the target were obtained by applying bilinear interpolation to the numerical blood velocity data. The effects on As of the type of ferromagnetic materials in the targets and MDCPs, average blood flow rates, mass fraction of the ferromagnetic material in the MDCPs, average radii of MDCPs (Rp) and the externally applied magnetic field strength (μ0H0) were evaluated. Furthermore, the appropriate μ0H0 and Rp for the IA-MDT design is suggested. In the case of the SS409 target and magnetite MDCPs, dimensionless capture areas ranging from 4.1- to 12.4 and corresponding to particle capture efficiencies of 31-94% were obtained with Rp ranging from 100- to 500 nm, weight fraction of 80%, μ0H0 of 0.6 T and an average blood flow rate of 0.01 ms-1. In addition, the more general 3-D modelling of IA-MDT in this work is applicable to IA-MDT using spherical targets implanted within blood vessels for both laminar and potential blood flows including the wall effect.

  5. Inherited neurovascular diseases affecting cerebral blood vessels and smooth muscle.

    Science.gov (United States)

    Sam, Christine; Li, Fei-Feng; Liu, Shu-Lin

    2015-10-01

    Neurovascular diseases are among the leading causes of mortality and permanent disability due to stroke, aneurysm, and other cardiovascular complications. Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and Marfan syndrome are two neurovascular disorders that affect smooth muscle cells through accumulation of granule and osmiophilic materials and defective elastic fiber formations respectively. Moyamoya disease, hereditary hemorrhagic telangiectasia (HHT), microcephalic osteodysplastic primordial dwarfism type II (MOPD II), and Fabry's disease are disorders that affect the endothelium cells of blood vessels through occlusion or abnormal development. While much research has been done on mapping out mutations in these diseases, the exact mechanisms are still largely unknown. This paper briefly introduces the pathogenesis, genetics, clinical symptoms, and current methods of treatment of the diseases in the hope that it can help us better understand the mechanism of these diseases and work on ways to develop better diagnosis and treatment.

  6. Effects of High-sugar and High-fat Diet on Fat Deposition and Blood Vessel Wall on Sprague Dawley Rats Liver

    Directory of Open Access Journals (Sweden)

    Vera Citra Setiawan Hoei

    2013-11-01

    Full Text Available People nowadays tend to consume more fast food and sweetened beverages. These foods usually contain high amount sugar and fat that have effects on the body including liver.This study was conducted to explore the effects of extensive intake of sugar and fat on blood glucose and  cholesterol level as well as changes in liver. Research was conducted with experimental method using 20 Sprague Dawley rats which were divided into 4 groups; 2 controls and 2 treatments. Rats were given 5 ml sugar or lard alternatively every 2 consecutive days for 1-month and 2-month respectively. Data was retrieved include blood glucose and cholesterol level, fatty liver percentage and blood vessel thickening after intervention through HE staining. The results showed that both 1-month and 2-month intervention group has significant increase in blood glucose and cholesterol level. However, the enhancement of fatty liver percentage and number of thickened blood vessels (p<0.05 were only foundsignificant (p<0.05 in 1-month intervention group.  We concluded that high intake of sugar and fat within 1-monthintervention have significant effects on the rat body including liver. Nevertheless, it was not found significant in 2-months intervention. Further studies are still needed to analyze this incongruent result.Key words: high-sugar diet, high-fat diet, fatty liver, atherosclerosis 

  7. Vacuum vessel for thermonuclear device

    International Nuclear Information System (INIS)

    Hagiwara, Koji; Imura, Yasuya.

    1979-01-01

    Purpose: To provide constituted method for easily performing baking of vacuum vessel, using short-circuiting segments. Constitution: At the time of baking, one turn circuit is formed by the vacuum vessel and short-circuiting segments, and current transformer converting the one turn circuit into a secondary circuit by the primary coil and iron core is formed, and the vacuum vessel is Joule heated by an induction current from the primary coil. After completion of baking, the short-circuiting segments are removed. (Kamimura, M.)

  8. Reactor Vessel and Reactor Vessel Internals Segmentation at Zion Nuclear Power Station - 13230

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, Conrad; Spann, Holger [Siempelkamp Nuclear Services: 5229 Sunset Blvd., (Suite M), West Columbia, SC, 29169 (United States)

    2013-07-01

    Zion Nuclear Power Station (ZNPS) is a dual-unit Pressurized Water Reactor (PWR) nuclear power plant located on the Lake Michigan shoreline, in the city of Zion, Illinois approximately 64 km (40 miles) north of Chicago, Illinois and 67 km (42 miles) south of Milwaukee, Wisconsin. Each PWR is of the Westinghouse design and had a generation capacity of 1040 MW. Exelon Corporation operated both reactors with the first unit starting production of power in 1973 and the second unit coming on line in 1974. The operation of both reactors ceased in 1996/1997. In 2010 the Nuclear Regulatory Commission approved the transfer of Exelon Corporation's license to ZionSolutions, the Long Term Stewardship subsidiary of EnergySolutions responsible for the decommissioning of ZNPS. In October 2010, ZionSolutions awarded Siempelkamp Nuclear Services, Inc. (SNS) the contract to plan, segment, remove, and package both reactor vessels and their respective internals. This presentation discusses the tools employed by SNS to remove and segment the Reactor Vessel Internals (RVI) and Reactor Vessels (RV) and conveys the recent progress. SNS's mechanical segmentation tooling includes the C-HORCE (Circumferential Hydraulically Operated Cutting Equipment), BMT (Bolt Milling Tool), FaST (Former Attachment Severing Tool) and the VRS (Volume Reduction Station). Thermal segmentation of the reactor vessels will be accomplished using an Oxygen- Propane cutting system. The tools for internals segmentation were designed by SNS using their experience from other successful reactor and large component decommissioning and demolition (D and D) projects in the US. All of the designs allow for the mechanical segmentation of the internals remotely in the water-filled reactor cavities. The C-HORCE is designed to saw seven circumferential cuts through the Core Barrel and Thermal Shield walls with individual thicknesses up to 100 mm (4 inches). The BMT is designed to remove the bolts that fasten the Baffle

  9. The absorbed dose to blood from blood-borne activity

    International Nuclear Information System (INIS)

    Hänscheid, H; Fernández, M; Lassmann, M

    2015-01-01

    The radiation absorbed dose to blood and organs from activity in the blood is relevant for nuclear medicine dosimetry and for research in biodosimetry. The present study provides coefficients for the average absorbed dose rates to the blood from blood-borne activity for radionuclides frequently used in targeted radiotherapy and in PET diagnostics. The results were deduced from published data for vessel radius-dependent dose rate coefficients and reasonable assumptions on the blood-volume distribution as a function of the vessel radius. Different parts of the circulatory system were analyzed separately. Vessel size information for heart chambers, aorta, vena cava, pulmonary artery, and capillaries was taken from published results of morphometric measurements. The remaining blood not contained in the mentioned vessels was assumed to reside in fractal-like vascular trees, the smallest branches of which are the arterioles or venules. The applied vessel size distribution is consistent with recommendations of the ICRP on the blood-volume distribution in the human. The resulting average absorbed dose rates to the blood per nuclear disintegration per milliliter (ml) of blood are (in 10 −11  Gy·s −1 ·Bq −1 ·ml) Y-90: 5.58, I-131: 2.49, Lu-177: 1.72, Sm-153: 2.97, Tc-99m: 0.366, C-11: 4.56, F-18: 3.61, Ga-68: 5.94, I-124: 2.55. Photon radiation contributes 1.1–1.2·10 −11  Gy·s −1 ·Bq −1 ·ml to the total dose rate for positron emitters but significantly less for the other nuclides. Blood self-absorption of the energy emitted by ß-particles in the whole blood ranges from 37% for Y-90 to 80% for Tc-99m. The correspondent values in vascular trees, which are important for the absorbed dose to organs, range from 30% for Y-90 to 82% for Tc-99m. (paper)

  10. Dilated thin-walled blood and lymphatic vessels in human endometrium: a potential role for VEGF-D in progestin-induced break-through bleeding.

    Directory of Open Access Journals (Sweden)

    Jacqueline F Donoghue

    Full Text Available Progestins provide safe, effective and cheap options for contraception as well as the treatment of a variety of gynaecological disorders. Episodes of irregular endometrial bleeding or breakthrough bleeding (BTB are a major unwanted side effect of progestin treatment, such that BTB is the leading cause for discontinued use of an otherwise effective and popular medication. The cellular mechanisms leading to BTB are poorly understood. In this study, we make the novel finding that the large, dilated, thin walled vessels characteristic of human progestin-treated endometrium include both blood and lymphatic vessels. Increased blood and lymphatic vessel diameter are features of VEGF-D action in other tissues and we show by immunolocalisation and Western blotting that stromal cell decidualisation results in a significant increase in VEGF-D protein production, particularly of the proteolytically processed 21 kD form. Using a NOD/scid mouse model with xenografted human endometrium we were able to show that progestin treatment causes decidualisation, VEGF-D production and endometrial vessel dilation. Our results lead to a novel hypothesis to explain BTB, with stromal cell decidualisation rather than progestin treatment per se being the proposed causative event, and VEGF-D being the proposed effector agent.

  11. Development of a system for measuring wall shear stress in blood vessels using magnetic resonance imaging and computational fluid dynamics

    International Nuclear Information System (INIS)

    Yoshida, Keita; Nagao, Taisuke; Okada, Kouji; Miyazaki, Shohei; Yang, Xiaomei; Yamazaki, Youichi; Murase, Kenya

    2008-01-01

    We developed a system for measuring the wall shear stress (WSS) in blood vessels using magnetic resonance imaging (MRI) and computational fluid dynamics (CFD). The time-dependent velocity at the center of the blood vessel was measured by phase-contrast MRI and was approximated by finite Fourier series, which was used for generating the velocity profile at the inlet for the boundary condition to the CFD method. To validate the CFD method, we compared the WSS obtained by the CFD method with the theoretical value in a straight cylinder with various radii for both steady and pulsatile flows. We also investigated the dependence of the WSS on the inlet velocity profile incorporated into the CFD method. For steady flow, there was a good agreement between the WSS obtained by the CFD method and the theoretical value. For pulsatile flow, there was a relatively good agreement between them when the radius of the cylinder was 2.5 mm and the inlet velocity profile was given by the Womersley solution for fully developed pulsatile flow in a straight circular cylinder. When the radius of the cylinder was 5 mm and/or the inlet velocity profile was assumed to be parabolic, large differences were observed between them, suggesting that the assumption of fully developed flow does not hold true in these cases. In human studies, the vortex due to the secondary blood flow in the carotid arterial sinus was clearly observed. The WSS in the bifurcation was the highest, while that in the carotid arterial sinus was the smallest. In conclusion, the system presented here appears to be useful for measuring the WSS in blood vessels and for analyzing the cause and/or extent of atherosclerosis, and our results suggest that the inlet velocity profile should be carefully considered. (author)

  12. Blood vessel formation during tail regeneration in the leopard gecko (Eublepharis macularius): The blastema is not avascular.

    Science.gov (United States)

    Payne, Samantha L; Peacock, Hanna M; Vickaryous, Matthew K

    2017-03-01

    Unique among amniotes, many lizards are able to self-detach (autotomize) their tail and then regenerate a replacement. Tail regeneration involves the formation of a blastema, an accumulation of proliferating cells at the site of autotomy. Over time, cells of the blastema give rise to most of the tissues in the replacement tail. In non-amniotes capable of regenerating (such as urodeles and some teleost fish), the blastema is reported to be essentially avascular until tissue differentiation takes place. For tail regenerating lizards less is known. Here, we investigate neovascularization during tail regeneration in the leopard gecko (Eublepharis macularius). We demonstrate that the gecko tail blastema is not an avascular structure. Beginning with the onset of regenerative outgrowth, structurally mature (mural cell supported) blood vessels are found within the blastema. Although the pattern of blood vessel distribution in the regenerate tail differs from that of the original, a hierarchical network is established, with vessels of varying luminal diameters and wall thicknesses. Using immunostaining, we determine that blastema outgrowth and tissue differentiation is characterized by a dynamic interplay between the pro-angiogenic protein vascular endothelial growth factor (VEGF) and the anti-angiogenic protein thrombospondin-1 (TSP-1). VEGF-expression is initially widespread, but diminishes as tissues differentiate. In contrast, TSP-1 expression is initially restricted but becomes more abundant as VEGF-expression wanes. We predict that variation in the neovascular response observed between different regeneration-competent species likely relates to the volume of the blastema. J. Morphol. 278:380-389, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  13. Porous hybrid structures based on P(DLLA-co-TMC) and collagen for tissue engineering of small-diameter blood vessels

    NARCIS (Netherlands)

    Buttafoco, L.; Boks, Niels P.; Engbers-Buijtenhuijs, P.; Grijpma, Dirk W.; Poot, Andreas A.; Dijkstra, Pieter J.; Vermes, I.; Feijen, Jan

    2006-01-01

    Poly (D,L-lactide)-7co-(1,3-trimethylene carbonate) [P(DLLA-co-TMC)] (83 mol % DLLA) was used to produce matrices suitable for tissue engineering of small-diameter blood vessels. The copolymer was processed into tubular structures with a porosity of 98% by melt spinning and fiber winding, thus

  14. Acidic sweep gas with carbonic anhydrase coated hollow fiber membranes synergistically accelerates CO2 removal from blood

    OpenAIRE

    Arazawa, D. T.; Kimmel, J. D.; Finn, M.C.; Federspiel, W. J.

    2015-01-01

    The use of extracorporeal carbon dioxide removal (ECCO2R) is well established as a therapy for patients suffering from acute respiratory failure. Development of next generation low blood flow (< 500 mL/min) ECCO2R devices necessitates more efficient gas exchange devices. Since over 90% of blood CO2 is transported as bicarbonate (HCO3−), we previously reported development of a carbonic anhydrase (CA) immobilized bioactive hollow fiber membrane (HFM) which significantly accelerates CO2 removal ...

  15. 3-D trajectory model for MDT using micro-spheres implanted within large blood vessels

    Science.gov (United States)

    Choomphon-anomakhun, Natthaphon; Natenapit, Mayuree

    2016-09-01

    Implant assisted magnetic drug targeting (IA-MDT) using ferromagnetic spherical targets implanted within large blood vessels and subjected to a uniform externally applied magnetic field (H0) has been investigated and reported for the first time. The capture areas (As) of magnetic drug carrier particles (MDCPs) were determined from the analysis of particle trajectories simulated from equations of motion. Then, the effects of various parameters, such as types of ferromagnetic materials in the targets and MDCPs, blood flow rates, mass fraction of the ferromagnetic material in the MDCPs, average radii of MDCPs (Rp) and the strength of H0 on the As were obtained. Furthermore, the effects of saturation magnetization of the ferromagnetic materials in the MDCPs and within the targets on the As were analyzed. After this, the suitable strengths of H0 and Rp for IA-MDT designs were reported. Dimensionless As, ranging from 2 to 7, was obtained with Rp ranging from 500 to 2500 nm, μ0H0 less than 0.8 T and a blood flow rate of 0.1 m s-1. The target-MDCP materials considered are iron-iron, iron-magnetite and SS409-magnetite, respectively.

  16. Method of removing radioactive waste from oil

    International Nuclear Information System (INIS)

    Belanger, R.L.

    1986-01-01

    This patent describes a method of removing particulates, radioactive contaminants, and moisture from oil, which consists of: straining out the particulates by passing the oil through a coarse filter screen to a receiving vessel; forming an upper stratum of oil and a lower stratum of sludge, consisting of mud, oil, particulates, and moisture, by heating the upper two-thirds of the receiving vessel; skimming off the stratum of oil from the receiving vessel; transferring the sludge from the receiving vessel to a container; transferring additional separated oil to the receiving vessel; conveying the oil skimmed from the receiving vessel to a mixing vessel; adding an effective amount of Calcium Hypochlorite crystals containing 65% free Chlorine to the mixing vessel to initiate salt formation with the radioactive contaminants; mixing the contents of the mixing vessel for at least ten minutes; transferring the mixture from the mixing vessel to a circulating heater; outputting the mixture from the circulating heater to a second mixing vessel; removing moisture from the oil; and filtering from the oil, the solid radioactive contaminant-salts and residual particulate matter

  17. In-vivo imaging of blood flow in human retinal vessels using color Doppler optical coherence tomography

    Science.gov (United States)

    Yazdanfar, Siavash; Rollins, Andrew M.; Izatt, Joseph A.

    1999-04-01

    Quantification of retinal blood flow may lead to a better understanding of the progression and treatment of several ocular disorders, including diabetic retinopathy, age- related macular degeneration, and glaucoma. Current techniques, such as fluorescein angiography and laser Doppler velocimetry are limited, failing to provide sufficient information to the clinician. Color Doppler optical coherence tomography (CDOCT) is a novel technique using coherent heterodyne detection for simultaneous cross- sectional imaging of tissue microstructure and blood flow. This technique is capable of high spatial and velocity resolution imaging in highly scattering media. We implemented CDOCT for retinal blood flow mapping in human subjects. No dilation of the pupil was necessary. CDOCT is demonstrated for determining bidirectional flow in sub- 100micrometers diameter vessels in the retina. Additionally, we calculated Doppler broadening using the variance of depth- resolved spectra to identify regions with large velocity gradients within the Xenopus heart. This technique may be useful in quantifying local tissue perfusion in highly vascular retinal tissue.

  18. Antibody-linked drug destroys tumor cells and tumor blood vessels in many types of cancer | Center for Cancer Research

    Science.gov (United States)

    A team led by Brad St. Croix, Ph.D., Senior Associate Scientist, Mouse Cancer Genetics Program, has developed an antibody-drug conjugate (ADC) that destroys both tumor cells and the blood vessels that nourish them. The drug significantly shrank breast tumors, colon tumors and several other types of cancer and prolonged survival. Learn more...  

  19. Vessel calibre and haemoglobin effects on pulse oximetry

    International Nuclear Information System (INIS)

    McEwen, M P; Reynolds, K J; Bull, G P

    2009-01-01

    Despite its success as a clinical monitoring tool, pulse oximetry may be improved with respect to the need for empirical calibration and the reports of biases in readings associated with peripheral vasoconstriction and haemoglobin concentration. To effect this improvement, this work aims to improve the understanding of the photoplethysmography signal—as used by pulse oximeters—and investigates the effect of vessel calibre and haemoglobin concentration on pulse oximetry. The digital temperature and the transmission of a wide spectrum of light through the fingers of 57 people with known haemoglobin concentrations were measured and simulations of the transmission of that spectrum of light through finger models were performed. Ratios of pulsatile attenuations of light as used in pulse oximetry were dependent upon peripheral temperature and on blood haemoglobin concentration. In addition, both the simulation and in vivo results showed that the pulsatile attenuation of light through fingers was approximately proportional to the absorption coefficients of blood, only when the absorption coefficients were small. These findings were explained in terms of discrete blood vessels acting as barriers to light transmission through tissue. Due to the influence of discrete blood vessels on light transmission, pulse oximeter outputs tend to be dependent upon haemoglobin concentration and on the calibre of pulsing blood vessels—which are affected by vasoconstriction/vasodilation. The effects of discrete blood vessels may account for part of the difference between the Beer–Lambert pulse oximetry model and empirical calibration

  20. A robust technique based on VLM and Frangi filter for retinal vessel extraction and denoising.

    Directory of Open Access Journals (Sweden)

    Khan Bahadar Khan

    Full Text Available The exploration of retinal vessel structure is colossally important on account of numerous diseases including stroke, Diabetic Retinopathy (DR and coronary heart diseases, which can damage the retinal vessel structure. The retinal vascular network is very hard to be extracted due to its spreading and diminishing geometry and contrast variation in an image. The proposed technique consists of unique parallel processes for denoising and extraction of blood vessels in retinal images. In the preprocessing section, an adaptive histogram equalization enhances dissimilarity between the vessels and the background and morphological top-hat filters are employed to eliminate macula and optic disc, etc. To remove local noise, the difference of images is computed from the top-hat filtered image and the high-boost filtered image. Frangi filter is applied at multi scale for the enhancement of vessels possessing diverse widths. Segmentation is performed by using improved Otsu thresholding on the high-boost filtered image and Frangi's enhanced image, separately. In the postprocessing steps, a Vessel Location Map (VLM is extracted by using raster to vector transformation. Postprocessing steps are employed in a novel way to reject misclassified vessel pixels. The final segmented image is obtained by using pixel-by-pixel AND operation between VLM and Frangi output image. The method has been rigorously analyzed on the STARE, DRIVE and HRF datasets.

  1. Large vessel involvement by IgG4-related disease

    Science.gov (United States)

    Perugino, Cory A.; Wallace, Zachary S.; Meyersohn, Nandini; Oliveira, George; Stone, James R.; Stone, John H.

    2016-01-01

    Abstract Objectives: IgG4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory condition that can affect multiple organs and lead to tumefactive, tissue-destructive lesions. Reports have described inflammatory aortitis and periaortitis, the latter in the setting of retroperitoneal fibrosis (RPF), but have not distinguished adequately between these 2 manifestations. The frequency, radiologic features, and response of vascular complications to B cell depletion remain poorly defined. We describe the clinical features, radiology findings, and treatment response in a cohort of 36 patients with IgG4-RD affecting large blood vessels. Methods: Clinical records of all patients diagnosed with IgG4-RD in our center were reviewed. All radiologic studies were reviewed. We distinguished between primary large blood vessel inflammation and secondary vascular involvement. Primary involvement was defined as inflammation in the blood vessel wall as a principal focus of disease. Secondary vascular involvement was defined as disease caused by the effects of adjacent inflammation on the blood vessel wall. Results: Of the 160 IgG4-RD patients in this cohort, 36 (22.5%) had large-vessel involvement. The mean age at disease onset of the patients with large-vessel IgG4-RD was 54.6 years. Twenty-eight patients (78%) were male and 8 (22%) were female. Thirteen patients (36%) had primary IgG4-related vasculitis and aortitis with aneurysm formation comprised the most common manifestation. This affected 5.6% of the entire IgG4-RD cohort and was observed in the thoracic aorta in 8 patients, the abdominal aorta in 4, and both the thoracic and abdominal aorta in 3. Three of these aneurysms were complicated by aortic dissection or contained perforation. Periaortitis secondary to RPF accounted for 27 of 29 patients (93%) of secondary vascular involvement by IgG4-RD. Only 5 patients demonstrated evidence of both primary and secondary blood vessel involvement. Of those treated with

  2. Vitamin K2 Ameliorates Damage of Blood Vessels by Glucocorticoid: a Potential Mechanism for Its Protective Effects in Glucocorticoid-induced Osteonecrosis of the Femoral Head in a Rat Model.

    Science.gov (United States)

    Zhang, Yuelei; Yin, Junhui; Ding, Hao; Zhang, Changqing; Gao, You-Shui

    2016-01-01

    Glucocorticoid has been reported to decrease blood vessel number and harm the blood supply in the femoral head, which is recognized to be an important mechanism of glucocorticoid-induced osteonecrosis of the femoral head (ONFH). To prevent glucocorticoid-induced ONFH, medication that promotes both bone formation and angiogenesis would be ideal. Vitamin K2 has been revealed to play an important role in bone metabolism; however, few studies have focused on the effect of Vitamin K2 on new vascular formation. Thus, this study aimed to investigate whether Vitamin K2 promoted new blood vessel formation in the presence of glucocorticoids, both in vitro and in vivo. The effect of Vitamin K2 on viability, migration, in vitro tube formation, and VEGF, vWF, CD31, KDR, Flt and PDGFB in EAhy926 incubated with or without dexamethasone were elucidated. VEGF, TGF-β and BMP-2, angiogenesis-related proteins secreted by osteoblasts, were also detected in the osteoblast-like cell line of MG63. In addition, blood vessels of the femoral head in rats administered with or without methylprednisolone and Vitamin K2 were evaluated using angiography and CD31 staining. In vitro studies showed that Vitamin K2 significantly protected endothelial cells from dexamethasone-induced apoptosis, promoted endothelial cell migration and in vitro tube formation. Angiogenesis-related proteins both in EAhy926 and MG63 were also upregulated by Vitamin K2 when cotreated with dexamethasone. In vivo studies showed enhanced blood vessel volume and CD31-positive staining cells in rats cotreated with VK2 and methylprednisolone compared to rats treated with methylprednisolone only. Collectively, Vitamin K2 has the ability to promote angiogenesis in vitro and to ameliorate vessels of the femoral head in glucocorticoid-treated rats in vivo, indicating that Vitamin K2 is a promising drug that may be used to prevent steroid-induced ONFH.

  3. An integrated 3-D image of cerebral blood vessels and CT view of tumor

    International Nuclear Information System (INIS)

    Suetens, P.; Baert, A.L.; Gybels, J.; Haegemans, S.; Jansen, P.; Oosterlinck, A.; Wilms, G.

    1984-01-01

    The authors developed a method that yields an integrated three-dimensional image of cerebral blood vessels and CT view of tumor. This method allows the neurosurgeon to choose any electrode trajectory that looks convenient to him, without imminent danger of causing a hemorrhage. Besides offering more safety to stereotactic interventions, this integrated 3-D image also has other applications. First, it gives a better characterization of most focal mass lesions seen by CT. Second, it allows high dose focal irradiation to be effected in such a way as to avoid arteries and veins. Third, it provides useful information for planning the strategy of open surgery

  4. Automated classification and quantitative analysis of arterial and venous vessels in fundus images

    Science.gov (United States)

    Alam, Minhaj; Son, Taeyoon; Toslak, Devrim; Lim, Jennifer I.; Yao, Xincheng

    2018-02-01

    It is known that retinopathies may affect arteries and veins differently. Therefore, reliable differentiation of arteries and veins is essential for computer-aided analysis of fundus images. The purpose of this study is to validate one automated method for robust classification of arteries and veins (A-V) in digital fundus images. We combine optical density ratio (ODR) analysis and blood vessel tracking algorithm to classify arteries and veins. A matched filtering method is used to enhance retinal blood vessels. Bottom hat filtering and global thresholding are used to segment the vessel and skeleton individual blood vessels. The vessel tracking algorithm is used to locate the optic disk and to identify source nodes of blood vessels in optic disk area. Each node can be identified as vein or artery using ODR information. Using the source nodes as starting point, the whole vessel trace is then tracked and classified as vein or artery using vessel curvature and angle information. 50 color fundus images from diabetic retinopathy patients were used to test the algorithm. Sensitivity, specificity, and accuracy metrics were measured to assess the validity of the proposed classification method compared to ground truths created by two independent observers. The algorithm demonstrated 97.52% accuracy in identifying blood vessels as vein or artery. A quantitative analysis upon A-V classification showed that average A-V ratio of width for NPDR subjects with hypertension decreased significantly (43.13%).

  5. Tubular inverse opal scaffolds for biomimetic vessels

    Science.gov (United States)

    Zhao, Ze; Wang, Jie; Lu, Jie; Yu, Yunru; Fu, Fanfan; Wang, Huan; Liu, Yuxiao; Zhao, Yuanjin; Gu, Zhongze

    2016-07-01

    There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially oriented elliptical pattern microstructures on their surfaces. It is demonstrated that these tailored tubular scaffolds can effectively make endothelial cells to form an integrated hollow tubular structure on their inner surface and induce smooth muscle cells to form a circumferential orientation on their outer surface. These features of our tubular scaffolds make them highly promising for the construction of biomimetic blood vessels.There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially

  6. About a mechanism of the influence of shear stress for viscosity of the blood in vessels of small diameter

    Directory of Open Access Journals (Sweden)

    Лев Николаевич Катюхин

    2014-12-01

    Full Text Available It is proposed a physiological and experimentally confirmed explanation of Fåhraeus-Lindqvist-effect in capillaries using the profile analyses of osmotic deformability of red blood cells. It was shown the dose-dependent change of the erythrocytes deformability in the stage of isotropic spheres after forming artificial water pores (nystatin and occlusion (PbCl2 of available pores. The Sigma-effect reducing of hematocrit and viscosity in a shear flow of blood through the vessels of a small diameter was conditioned by the interchange of liquid phase between the erythrocyte and the plasma.

  7. Infrared tomography for diagnostic imaging of port wine stain blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, D. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    The objective of this work is the development of Infrared Tomography (IRT) for detecting and characterizing subsurface chromophores in human skin. Characterization of cutaneous chromophores is crucial for advances in the laser treatment of pigmented lesions (e.g., port wine stain birthmarks and tatoos). Infrared tomography (IRT) uses a fast infrared focal plane array (IR-FPA) to detect temperature rises in a substrate induced by pulsed radiation. A pulsed laser is used to produce transient heating of an object. The temperature rise, due to the optical absorption of the pulsed laser light, creates an increase in infrared emission which is measured by the IR-FPA. Although the application of IRT to image subsurface cracks due to metal fatigue is a topic of great interest in the aircraft industry, the application to image subsurface chromophores in biological materials is novel. We present an image recovery method based on a constrained conjugate gradient algorithm that has obtained the first ever high quality images of port wine blood vessels.

  8. Insulin-like Growth Factor 1 (IGF-1) Stabilizes Nascent Blood Vessels*

    Science.gov (United States)

    Jacobo, Sarah Melissa P.; Kazlauskas, Andrius

    2015-01-01

    Here we report that VEGF-A and IGF-1 differ in their ability to stabilize newly formed blood vessels and endothelial cell tubes. Although VEGF-A failed to support an enduring vascular response, IGF-1 stabilized neovessels generated from primary endothelial cells derived from various vascular beds and mouse retinal explants. In these experimental systems, destabilization/regression was driven by lysophosphatidic acid (LPA). Because previous studies have established that Erk antagonizes LPA-mediated regression, we considered whether Erk was an essential component of IGF-dependent stabilization. Indeed, IGF-1 lost its ability to stabilize neovessels when the Erk pathway was inhibited pharmacologically. Furthermore, stabilization was associated with prolonged Erk activity. In the presence of IGF-1, Erk activity persisted longer than in the presence of VEGF or LPA alone. These studies reveal that VEGF and IGF-1 can have distinct inputs in the angiogenic process. In contrast to VEGF, IGF-1 stabilizes neovessels, which is dependent on Erk activity and associated with prolonged activation. PMID:25564613

  9. Quantitative ex-vivo micro-computed tomographic imaging of blood vessels and necrotic regions within tumors.

    Science.gov (United States)

    Downey, Charlene M; Singla, Arvind K; Villemaire, Michelle L; Buie, Helen R; Boyd, Steven K; Jirik, Frank R

    2012-01-01

    Techniques for visualizing and quantifying the microvasculature of tumors are essential not only for studying angiogenic processes but also for monitoring the effects of anti-angiogenic treatments. Given the relatively limited information that can be gleaned from conventional 2-D histological analyses, there has been considerable interest in methods that enable the 3-D assessment of the vasculature. To this end, we employed a polymerizing intravascular contrast medium (Microfil) and micro-computed tomography (micro-CT) in combination with a maximal spheres direct 3-D analysis method to visualize and quantify ex-vivo vessel structural features, and to define regions of hypoperfusion within tumors that would be indicative of necrosis. Employing these techniques we quantified the effects of a vascular disrupting agent on the tumor vasculature. The methods described herein for quantifying whole tumor vascularity represent a significant advance in the 3-D study of tumor angiogenesis and evaluation of novel therapeutics, and will also find potential application in other fields where quantification of blood vessel structure and necrosis are important outcome parameters.

  10. Pericyte coverage of abnormal blood vessels in myelofibrotic bone marrows

    DEFF Research Database (Denmark)

    Zetterberg, Eva; Vannucchi, Alessandro M; Migliaccio, Anna Rita

    2007-01-01

    BACKGROUND AND OBJECTIVES: Myelofibrotic bone marrow displays abnormal angiogenesis but the pathogenic mechanisms of this are poorly understood. Since pericyte abnormalities are described on solid tumor vessels we studied whether vessel morphology and pericyte coverage in bone marrow samples from...

  11. [Aetiology and pathogenesis of damages to blood vessels in drug addicts].

    Science.gov (United States)

    Sultanaliev, T A; Tursynbaev, S E; Ivakin, V M

    2007-01-01

    The article deals with the problems concerning aetiology and pathogenesis of damages to blood vessels in patients practicing parenteral administration of surrogates of narcotic substances. In order to clinically and experimentally study the pattern of morphological alterations in the area of narcotic substances administration and to work out an appropriate classification of the forms and stages of development of the pathological process, the authors analysed the clinical course of vascular lesions and complications thereof in a total of 244 drug abusers having parenterally administered surrogates of narcotic substances and undergoing treatment at the Department of Vascular Surgery of the Municipal Clinical Hospital of the city of Almaty. Additionally, experimental studies were carried out on 16 rabbits with the induced model of parenteral administration of surrogates of narcotic substances, thus making it possible to study the degree of their effect and to confirm the theory of a chemical impact of the homemade drugs on the vascular wall. The findings of the carried out studies enabled us to single out the following clinical stages of vascular lesions: stage I - the initial stage of cicatricial-and-ulcerous lesions formation, stage II - formation of cutaneous-and-vascular fistulas, stage III - the stage of complications characterized by development of health-hazardous vascular lesions, i. e., arterial and venous thromboses of the major vessels, as well as arrosive bleedings. It was noted that more than 50% of patients were admitted to the clinic presenting with the third stage of vascular lesions. The experimental part of the study included 64 experiments on 16 rabbits (one experiment per each paw of the animal). The laboratory animals were subdivided into three groups. The first experimental group consisted of the rabbits with a mechanically inflicted injury to the vessels. The second and third experimental groups were composed of the rabbits having received

  12. Blood vessels in subcaruncular and intercaruncular bovine endometriun possess oxytocin receptors (ORT) and express otr mRNA during pregnancy

    DEFF Research Database (Denmark)

    Fuchs, Anna-Ritta; Balvers, Marga; Ivell, Richard

    2002-01-01

    is taking place; marked changes were observed with advancing pregnancy. The epithelial cells of the trophoblast were strongly stained for ir OTR and OTR mRNA, as reported last year, but the fetal connective tissue and blood vessels within the trophoblast did not show any stain for ir OTR or OTR m...... placentation because episodic secretion of OT occurs throughout bovine pregnancy...

  13. A method for increasing the homogeneity of the temperature distribution during magnetic fluid hyperthermia with a Fe-Cr-Nb-B alloy in the presence of blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yundong [College of Physics and Information Engineering, Fuzhou University, Fuzhou 350116 (China); Flesch, Rodolfo C.C. [Departamento de Automação e Sistemas, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Jin, Tao, E-mail: jintly@fzu.edu.cn [College of Electrical Engineering and Automation, Fuzhou University, Fuzhou 350116 (China)

    2017-06-15

    Highlights: • The effects of blood vessels on temperature field distribution are investigated. • The critical thermal energy of hyperthermia is computed by the Finite Element Analysis. • A treatment method is proposed by using the MNPs with low Curie temperature. • The cooling effects due to the blood flow can be controlled. - Abstract: Magnetic hyperthermia ablates tumor cells by absorbing the thermal energy from magnetic nanoparticles (MNPs) under an external alternating magnetic field. The blood vessels (BVs) within tumor region can generally reduce treatment effectiveness due to the cooling effect of blood flow. This paper aims to investigate the cooling effect of BVs on the temperature field of malignant tumor regions using a complex geometric model and numerical simulation. For deriving the model, the Navier-Stokes equation for blood flow is combined with Pennes bio-heat transfer equation for human tissue. The effects on treatment temperature caused by two different BV distributions inside a mammary tumor are analyzed through numerical simulation under different conditions of flow rate considering a Fe-Cr-Nb-B alloy, which has low Curie temperature ranging from 42 °C to 45 °C. Numerical results show that the multi-vessel system has more obvious cooling effects than the single vessel one on the temperature field distribution for hyperthermia. Besides, simulation results show that the temperature field within tumor area can also be influenced by the velocity and diameter of BVs. To minimize the cooling effect, this article proposes a treatment method based on the increase of the thermal energy provided to MNPs associated with the adoption of low Curie temperature particles recently reported in literature. Results demonstrate that this approach noticeably improves the uniformity of the temperature field, and shortens the treatment time in a Fe-Cr-Nb-B system, thus reducing the side effects to the patient.

  14. 40 CFR 229.2 - Transport of target vessels.

    Science.gov (United States)

    2010-07-01

    ... marine navigation is not otherwise impaired by the sunk vessel; (3) All such vessel sinkings shall be... may degrade the marine environment, -including without limitation (i) emptying of all fuel tanks and... free of petroleum, and (ii) removing from the hulls other pollutants and all readily detachable...

  15. Engineering blood vessels through micropatterned co-culture of vascular endothelial and smooth muscle cells on bilayered electrospun fibrous mats with pDNA inoculation.

    Science.gov (United States)

    Liu, Yaowen; Lu, Jinfu; Li, Huinan; Wei, Jiaojun; Li, Xiaohong

    2015-01-01

    Although engineered blood vessels have seen important advances during recent years, proper mechanical strength and vasoactivity remain unsolved problems. In the current study, micropatterned fibrous mats were created to load smooth muscle cells (SMC), and a co-culture with endothelial cells (EC) was established through overlaying on an EC-loaded flat fibrous mat to mimic the layered structure of a blood vessel. A preferential distribution of SMC was determined in the patterned regions throughout the fibrous scaffolds, and aligned fibers in the patterned regions provided topological cues to guide the orientation of SMC with intense actin filaments and extracellular matrix (ECM) production in a circumferential direction. Plasmid DNA encoding basic fibroblast growth factors and vascular endothelial growth factor were integrated into electrospun fibers as biological cues to promote SMC infiltration into fibrous mats, and the viability and ECM production of both EC and SMC. The layered fibrous mats with loaded EC and SMC were wrapped into a cylinder, and engineered vessels were obtained with compact EC and SMC layers after co-culture for 3 months. Randomly oriented ECM productions of EC formed a continuous endothelium covering the entire lumenal surface, and a high alignment of ECM was shown in the circumferential direction of SMC layers. The tensile strength, strain at failure and suture retention strength were higher than those of the human femoral artery, and the burst pressure and radial compliance were in the same range as the human saphenous vein, indicating potential as blood vessel substitutes for transplantation in vivo. Thus, the establishment of topographical cues and biochemical signals in fibrous scaffolds demonstrates advantages in modulating cellular behavior and organization found in complex multicellular tissues. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  16. Ultrasound sonication with microbubbles disrupts blood vessels and enhances tumor treatments of anticancer nanodrug

    Directory of Open Access Journals (Sweden)

    Lin CY

    2012-04-01

    Full Text Available Chung-Yin Lin1*, Hsiao-Ching Tseng1*, Heng-Ruei Shiu1, Ming-Fang Wu2, Cheng-Ying Chou3, Win-Li Lin1,41Institute of Biomedical Engineering, 2Laboratory Animal Center, 3Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, Taipei, Taiwan; 4Division of Medical Engineering Research, National Health Research Institutes, Miaoli, Taiwan*These authors contributed equally to this workAbstract: Ultrasound (US sonication with microbubbles (MBs has the potential to disrupt blood vessels and enhance the delivery of drugs into the sonicated tissues. In this study, mouse ear tumors were employed to investigate the therapeutic effects of US, MBs, and pegylated liposomal doxorubicin (PLD on tumors. Tumors started to receive treatments when they grew up to about 15 mm3 (early stage with injection of PLD 10 mg/kg, or up to 50 mm3 (medium stage with PLD 6 (or 4 mg/kg. Experiments included the control, PLD alone, PLD + MBs + US, US alone, and MBs + US groups. The procedure for the PLD + MBs + US group was that PLD was injected first, MB (SonoVue injection followed, and then US was immediately sonicated on the tumor. The results showed that: (1 US sonication with MBs was always able to produce a further hindrance to tumor growth for both early and medium-stage tumors; (2 for the medium-stage tumors, 6 mg/kg PLD alone was able to inhibit their growth, while it did not work for 4 mg/kg PLD alone; (3 with the application of MBs + US, 4 mg/kg PLD was able to inhibit the growth of medium-stage tumors; (4 for early stage tumors after the first treatment with a high dose of PLD alone (10 mg/kg, the tumor size still increased for several days and then decreased (a biphasic pattern; (5 MBs + US alone was able to hinder the growth of early stage tumors, but unable to hinder that of medium stage tumors. The results of histological examinations and blood perfusion measurements indicated that the application of MBs + US disrupts the tumor blood

  17. Gain-of-function somatic mutations contribute to inflammation and blood vessel damage that lead to Alzheimer dementia: a hypothesis.

    Science.gov (United States)

    Marchesi, Vincent T

    2016-02-01

    Amyloid deposits are a characteristic feature of advanced Alzheimer dementia (AD), but whether they initiate the disease or are a consequence of it remains an unsettled question. To explore an alternative pathogenic mechanism, I propose that the triggering events that begin the pathogenic cascade are not amyloid deposits but damaged blood vessels caused by inflammatory reactions that lead to ischemia, amyloid accumulation, axonal degeneration, synaptic loss, and eventually irreversible neuronal cell death. Inflammation and blood vessel damage are well recognized complications of AD, but what causes them and why the cerebral microvasculature is affected have never been adequately addressed. Because heritable autosomal dominant mutations of NLRP3, APP, TREX1, NOTCH3, and Col4A1 are known to provoke inflammatory reactions and damage the brain in a wide variety of diseases, I propose that one or more low abundant, gain-of-function somatic mutations of the same 5 gene families damage the microvasculature of the brain that leads to dementia. This implies that the pathogenic triggers that lead to AD are derived not from external invaders or amyloid but from oxidative damage of our own genes. © FASEB.

  18. Effects of irradiation on renal vessels of rabbits

    International Nuclear Information System (INIS)

    Hanayama, Hirotaka

    1982-01-01

    The male rabbits weighing approximately 3 kg were divided into two groups: one group received irradiation to the left kidney through 6 x 4 cm field size with doses of 5 Gy, while the other group was irradiated with 50 Gy. The vessel casts were observed using the injection replica scanning electron microscopic method. In 50 Gy irradiated group, the surface of blood vessel's lumen became irregular with a decrease in the number of glomeruli at 5 days. Partial narrowing was also seen in the cortex and glomerular vessels. The number of glomeruli decreased by 48% one week later and 90% 4 weeks later. The cortex vessels progressively narrowed, and irregularity of the net-like structure was also observed. Similarly, a decrease in the number of glomeruli and partial narrowing of the blood vessels were seen at 5 days on the nonirradiated side, but the damage was considerably less than that on the irradiated side. In the 5 Gy irradiated group, a decrease in the number of glomeruli was seen 5 days later and it became 71% 5 days later and 81% one week later. It returned to 95% 4 weeks later. No changes whatsoever were seen in the non-irradiated side after 4 weeks and changes in the number of glomeruli were not observed. The vasculation of medulla showed no changes in the 50 Gy or the 5 Gy irradiated group. There were seen no significant changes in the blood vessel diameter. (J.P.N.)

  19. A kinematic study of pulsation in the dorsal blood vessel of the blackworm, Lumbriculus variegatus

    Directory of Open Access Journals (Sweden)

    Kameko Halfmann

    2011-01-01

    Full Text Available The aquatic oligochaete Lumbriculus variegatus has a segmented, dorsal blood vessel (DBV that acts as a peristaltic pump to move blood through the animal's closed circulatory system. We conducted a kinematic study using videography and computational modeling as a first step toward understanding the control of DBV pulsation. Results suggested that pulse rates were highest in the posterior segments, while interpulse intervals and intersegmental delays were longest in the midbody segments. Differences in the interpulse interval distributions across regions suggest that some peristaltic waves initiated in the posterior segments do not propagate all the way to the anterior segments. A simple model consisting of a chain of excitable neuromuscular units replicated these kinetics. This model may be useful in future research aimed at understanding the modulatory effect of biogenic amines on peristalsis of the DBV. Moreover, research into the mechanisms of peristalsis of the DBV may lead to insights into disorders of peristalsis in human and veterinary medicine

  20. Treatment of radiation exposure and regeneration medicine. Regeneration treatment of blood vessels by transplantation of autologous marrow monocytes

    International Nuclear Information System (INIS)

    Nagai, Kazuhiro; Kamihira, Shimeru; Matsumaru, Ichiro; Fukushima, Takuya; Yamaguchi, Hakuichiro; Miyazaki, Yasushi; Yamachika, Shiro; Eishi, Kiyoyuki; Tomonaga, Masao

    2007-01-01

    Described are usefulness and future view of regenerative medicine in the treatment of radiation exposure as exemplified by the vascular regeneration by autologous marrow cell transplantation. Vascular endothelial cells (VEC), possessing a high ability to divide, are known sensitive to radiation, which gives damage of blood vessel to alter its permeability leading to apoptosis of VEC, organ/tissue injuries and final damages in the cerebral blood vessels, central nervous system and skin, the acute radiation syndrome (ARS). Authors present successful cases of patients with chronic limb ischemia in the Therapeutic Angiogenesis using Cell Transplantation Trial (TACT), to whom the treatment is conducted with transplantation of autologous marrow monocyte fraction containing endothelial progenitor cells that differentiate to VEC. As well, they touch on a case of the patient encountered in a nuclear accident, mentioning that VEC are found partly derived from the donor after heamatopoietic stem cell transplantation (HSCT). Efficacy of HSCT in a literature is reviewed and commented to be an only limited one in 31 patients of various radiation accidents. However, treatment of ARS where stem cells are target, with regenerative medicine will become more useful in future, as basic and clinical researches will provide requisite findings. (T.I.)

  1. [Hemodynamic phenomena in retrobulhar and eyeball vessels].

    Science.gov (United States)

    Modrzejewska, Monika

    2011-01-01

    The purpose of this review was to evaluate factors connected with blood flow and indices regulating vascular diameter and some parameters influencing retrobulbar circulation such as type of vascular resistance, anatomical structure of vascular wall and vessel lumen. Neurogenic and angiogenic factors, rheological blood composition, presence of anatomical and pathological obstructions on blood flow pathway as well as degree of development of collateral circulation pathways--have influence on the volume and blood flow velocity in eyeball. There were discussed bulbar circulation hemodynamics, emphasizing the importance of perfusion pressure. The role of risk factors was underlined for pathological lesions in vessels supplying blood to eyeball and in ophthalmic artery (OA) and its collaterals, in central retinal artery (CRA) as well as posterior ciliary arteries (PCAs), and in venous system carrying away blood from eye. IN CONCLUSION--the results of many studies of retrobulbar blood flow in different types of ophthalmic diseases of the vascular etiopathogenesis indicate that registry of the mean values of blood flow parameters and vascular resistance indices parallel to measurement of blood flow spectrum in OA, CRA, PCAs arteries, might contribute much information to explain or to evaluate nature of pathological changes in retinal and choroidal circulation.

  2. Assessment of the advantages of a residual heat removal system inside the reactor pressure vessel

    International Nuclear Information System (INIS)

    Gautier, G.M.

    1995-01-01

    In the framework of research on diversified means for removing the residual heat from pressurized water reactors, the CEA is studying a passive system called RRP (Refroidissement du Reacteur au Primaire, or primary circuit cooling system), which includes integrated heat-exchangers and a layout of the internal structures so as to obtain convection from the primary circuit inside the vessel, whatever the state of the loops. This system is operational for all primary circuit temperatures and pressures, as well as for a wide range of conditions: it is independent of the state of the loops, even if the volume of water in the primary circuit is small, it is compatible with either a passive or an active operation mode, and compatible with any other decay heat removal systems. An evaluation is presented here of the performance of the RRP system in the event of a small primary circuit break in a totally passive operation mode without the intervention of another system. The results of this evaluation show the interest of such a system: a clear increase of the time-delay for the implementation of a low pressure safety injection system, no need for the use of a high pressure safety injection system. (author). 4 refs., 7 figs., 1 tab

  3. Assessment of the advantages of a residual heat removal system inside the reactor pressure vessel

    Energy Technology Data Exchange (ETDEWEB)

    Gautier, G.M. [Commissariat a l`Energie Atomique, Saint-Paul-Lez-Durance (France)

    1995-09-01

    In the framework of research on diversified means for removing residual heat from pressurized water reactors, the CEA is studying a passive system called RRP (Refroidissement du Reacteur au Primaire, or primary circuit cooling system). This system consists of integrated heat-exchangers and a layout of the internal structures so as to obtain convection from the primary circuit inside the vessel, whatever the state of the loops. This system is operational for all primary circuit temperatures and pressures, as well as for a wide range of conditions: such as independent from the state of the loops, low volume of water in the primary circuit, compatibility with either a passive or an active operation mode, and compatibility with any other decay heat removal systems. This paper presents an evaluation of the performance of the RRP system in the event of a small primary circuit break in a totally passive operation mode without the intervention of any another system. The results of this evaluation show the potential interest of such a system: a clear increase of the time-delay for the implementation of a low pressure safety injection system and no need for the use of a high pressure safety injection system.

  4. Effect of heat transfer on unsteady MHD flow of blood in a permeable vessel in the presence of non-uniform heat source

    Directory of Open Access Journals (Sweden)

    A. Sinha

    2016-09-01

    Full Text Available This paper presents a theoretical analysis of blood flow and heat transfer in a permeable vessel in the presence of an external magnetic field. The unsteadiness in the coupled flow and temperature fields is considered to be caused due to the time-dependent stretching velocity and the surface temperature of the vessel. The non-uniform heat source/sink effect on blood flow and heat transfer is taken into account. This study is of potential value in the clinical treatment of cardiovascular disorders accompanied by accelerated circulation. The problem is treated mathematically by reducing it to a system of coupled nonlinear differential equations, which have been solved by using similarity transformation and boundary layer approximation. The resulting nonlinear coupled ordinary differential equations are solved numerically by using an implicit finite difference scheme. Computational results are obtained for the velocity, temperature, the skin-friction coefficient and the rate of heat transfer in the vessel. The estimated results are compared with another analytical study reported earlier in scientific literatures. The present study reveals that the heat transfer rate is enhanced as the value of the unsteadiness parameter increases, but it reduces as the space-dependence parameter for heat source/sink increases.

  5. Neutron Assay System for Confinement Vessel Disposition

    International Nuclear Information System (INIS)

    Frame, Katherine C.; Bourne, Mark M.; Crooks, William J.; Evans, Louise; Mayo, Douglas R.; Miko, David K.; Salazar, William R.; Stange, Sy; Valdez, Jose I.; Vigil, Georgiana M.

    2012-01-01

    Los Alamos National Laboratory has a number of spherical confinement vessels (CVs) remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1-inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the CVs. The Confinement Vessel Assay System (CVAS) was developed to measure the amount of special nuclear material (SNM) in CVs before and after cleanout. Prior to cleanout, the system will be used to perform a verification measurement of each vessel. After cleanout, the system will be used to perform safeguards-quality assays of (le)100-g 239 Pu equivalent in a vessel for safeguards termination. The CVAS has been tested and calibrated in preparation for verification and safeguards measurements.

  6. Dissociation between vascular endothelial growth factor receptor-2 and blood vessel density in the caudate nucleus after chronic hydrocephalus.

    Science.gov (United States)

    Deshpande, Abhishek; Dombrowski, Stephen M; Leichliter, Anna; Krajcir, Natalie; Zingales, Nicholas; Inoue, Masahiro; Schenk, Soren; Fukamachi, Kiyotaka; Luciano, Mark G

    2009-11-01

    Chronic hydrocephalus (CH) is characterized by the presence of ventricular enlargement, decreased cerebral blood flow (CBF), and brain tissue oxygen delivery. Although the underlying pathophysiological role of vascular endothelial growth factor (VEGF) is not clear, ischemic-hypoxic events in CH are known to trigger its release. Previously, we have shown increased VEGF receptor-2 (VEGFR-2) and blood vessel density (BVd) in the hippocampus after CH. We investigated changes in neuronal and glial VEGFR-2 density and BVd in the caudate nucleus in an experimental model of CH. Animals with CH were divided into short term (ST, 2 to 4 weeks) and long term (LT, 12 to 16 weeks) and were compared with surgical controls (SCs, 12 to 16 weeks). The cellular and BVds were estimated using immunohistochemical and stereological counting methods. Overall, percentage (%)VEGFR-2 neurons were approximately two times greater in CH (ST, LT) than in SC. By comparison, glial cell %VEGFR-2 was greater by 10% to 17% in ST and 4% to 11% lower in LT compared with that in SC. Blood vessel density was significantly lower in CH than in SC in the superficial caudate. Changes in cerebrospinal fluid ventricular volume and pressure, as well as in CBF did not correlate with either VEGFR-2 or BVd. These observed findings suggest that destructive forces may outweigh angiogenic forces and possibly show a disassociation between VEGFR-2 and BV expressions.

  7. Safety technology qualification of the prestressed cast iron pressure vessel (PCIV) and of the primary cell of the HTR-modul for the passive removal of decay heat, phase 1 (INHR)

    International Nuclear Information System (INIS)

    Warnke, E.P.

    1990-02-01

    During this development program the thermodynamic behaviour of a system was investigated, consisting of a hot working Prestressed Cast Iron Pressure Vessel and an inactive heat sink in the surrounding cavern cell. It could be shown, that the inactive heat removal system designed as a natural circuit can remove the maximum amount of heat of 890 kW during emergency conditions via a natural-draught air cooling tower even under very conservative assumptions and for a 50% loss of cooling pipes. Further it could be shown, that the hot working Prestressed Cast Iron Pressure Vessel has a very safe load carrying behaviour during all normal and upset conditions. (orig.) With 10 tabs., 38 figs., 43 refs [de

  8. Wrong theories on the origin of blood vessels: Polybus and De Natura Hominis.

    Science.gov (United States)

    Shoja, Mohammadali M; Tubbs, R Shane; Loukas, Marios; Ardalan, Mohammad R

    2008-06-06

    Polybus of Cos (approximately 400 B.C.) was the son-in-law and the successor of Hippocrates. He is credited with founding the school of Dogmatism, and writing "The Nature of Man" which was important in advancing the theory of the four body humors (humoralism). Some earlier scholars negated Polybus' role as an independent medical figure. However, Corpus Aristotelicum quoted him as having a unique theory regarding the body vasculature which stated that this system was composed of four pairs of blood vessels originating from the head and that these supplied the whole body. In an interpretation of this theory, we opined that numerological mysticism might have been the common motive for both Hippocrates' humoralism and Polybus' theory of the vasculature. A discussion on this issue is presented.

  9. A novel method of selective removal of human DNA improves PCR sensitivity for detection of Salmonella Typhi in blood samples.

    Science.gov (United States)

    Zhou, Liqing; Pollard, Andrew J

    2012-07-27

    Enteric fever is a major public health problem, causing an estimated 21million new cases and 216,000 or more deaths every year. Current diagnosis of the disease is inadequate. Blood culture only identifies 45 to 70% of the cases and is time-consuming. Serological tests have very low sensitivity and specificity. Clinical samples obtained for diagnosis of enteric fever in the field generally have blood, so that even PCR-based methods, widely used for detection of other infectious diseases, are not a straightforward option in typhoid diagnosis. We developed a novel method to enrich target bacterial DNA by selective removal of human DNA from blood samples, enhancing the sensitivity of PCR tests. This method offers the possibility of improving PCR assays directly using clinical specimens for diagnosis of this globally important infectious disease. Blood samples were mixed with ox bile for selective lysis of human blood cells and the released human DNA was then digested with addition of bile resistant micrococcal nuclease. The intact Salmonella Typhi bacteria were collected from the specimen by centrifugation and the DNA extracted with QIAamp DNA mini kit. The presence of Salmonella Typhi bacteria in blood samples was detected by PCR with the fliC-d gene of Salmonella Typhi as the target. Micrococcal nuclease retained activity against human blood DNA in the presence of up to 9% ox bile. Background human DNA was dramatically removed from blood samples through the use of ox bile lysis and micrococcal nuclease for removal of mammalian DNA. Consequently target Salmonella Typhi DNA was enriched in DNA preparations and the PCR sensitivity for detection of Salmonella Typhi in spiked blood samples was enhanced by 1,000 fold. Use of a combination of selective ox-bile blood cell lysis and removal of human DNA with micrococcal nuclease significantly improves PCR sensitivity and offers a better option for improved typhoid PCR assays directly using clinical specimens in diagnosis of

  10. Application of optical coherence tomography for in vivo monitoring of the meningeal lymphatic vessels during opening of blood-brain barrier: mechanisms of brain clearing

    Science.gov (United States)

    Semyachkina-Glushkovskaya, Oxana; Abdurashitov, Arkady; Dubrovsky, Alexander; Bragin, Denis; Bragina, Olga; Shushunova, Nataliya; Maslyakova, Galina; Navolokin, Nikita; Bucharskaya, Alla; Tuchin, Valery; Kurths, Juergen; Shirokov, Alexander

    2017-12-01

    The meningeal lymphatic vessels were discovered 2 years ago as the drainage system involved in the mechanisms underlying the clearance of waste products from the brain. The blood-brain barrier (BBB) is a gatekeeper that strongly controls the movement of different molecules from the blood into the brain. We know the scenarios during the opening of the BBB, but there is extremely limited information on how the brain clears the substances that cross the BBB. Here, using the model of sound-induced opening of the BBB, we clearly show how the brain clears dextran after it crosses the BBB via the meningeal lymphatic vessels. We first demonstrate successful application of optical coherence tomography (OCT) for imaging of the lymphatic vessels in the meninges after opening of the BBB, which might be a new useful strategy for noninvasive analysis of lymphatic drainage in daily clinical practice. Also, we give information about the depth and size of the meningeal lymphatic vessels in mice. These new fundamental data with the applied focus on the OCT shed light on the mechanisms of brain clearance and the role of lymphatic drainage in these processes that could serve as an informative platform for a development of therapy and diagnostics of diseases associated with injuries of the BBB such as stroke, brain trauma, glioma, depression, or Alzheimer disease.

  11. Lining up device for the internal structures of a nuclear reactor vessel

    International Nuclear Information System (INIS)

    Silverblatt, B.L.

    1977-01-01

    The invention concerns a nuclear reactor of the type with a vessel, a vessel head carried at the top of this vessel by a core cylinder comprising a flange internally supported by the vessel, and an upper support structure supported between the core cylinder flange and the vessel head to align laterally the head, vessel, flange and support structure. A bottom key device is provided for lining up the flange, support structure and vessel, and an upper key device for laterally lining up support structure and the vessel head and for maintaining this alignment when they are removed simultaneously from the core cylinder and vessel. When re-assembling the reactor, the top support structure and the vessel head are lowered simultaneously so that an opening in the top alignment structure engages in the upper extension of the bottom alignment structure. A plurality of alignment stuctures may be utilised round the circumference of the reactor vessel. The disposition of the invention also facilitates the removal of the core cylinder from the reactor vessel. In this way, the alignment on re-assembly is ensured by the re-entry of the bottom extension under the flange of the core cylinder with the groove or keyway of the reactor vessel [fr

  12. Unsupervised Retinal Vessel Segmentation Using Combined Filters.

    Directory of Open Access Journals (Sweden)

    Wendeson S Oliveira

    Full Text Available Image segmentation of retinal blood vessels is a process that can help to predict and diagnose cardiovascular related diseases, such as hypertension and diabetes, which are known to affect the retinal blood vessels' appearance. This work proposes an unsupervised method for the segmentation of retinal vessels images using a combined matched filter, Frangi's filter and Gabor Wavelet filter to enhance the images. The combination of these three filters in order to improve the segmentation is the main motivation of this work. We investigate two approaches to perform the filter combination: weighted mean and median ranking. Segmentation methods are tested after the vessel enhancement. Enhanced images with median ranking are segmented using a simple threshold criterion. Two segmentation procedures are applied when considering enhanced retinal images using the weighted mean approach. The first method is based on deformable models and the second uses fuzzy C-means for the image segmentation. The procedure is evaluated using two public image databases, Drive and Stare. The experimental results demonstrate that the proposed methods perform well for vessel segmentation in comparison with state-of-the-art methods.

  13. Tumors induce coordinate growth of artery, vein, and lymphatic vessel triads

    International Nuclear Information System (INIS)

    Ruddell, Alanna; Croft, Alexandra; Kelly-Spratt, Karen; Furuya, Momoko; Kemp, Christopher J

    2014-01-01

    Tumors drive blood vessel growth to obtain oxygen and nutrients to support tumor expansion, and they also can induce lymphatic vessel growth to facilitate fluid drainage and metastasis. These processes have generally been studied separately, so that it is not known how peritumoral blood and lymphatic vessels grow relative to each other. The murine B16-F10 melanoma and chemically-induced squamous cell carcinoma models were employed to analyze large red-colored vessels growing between flank tumors and draining lymph nodes. Immunostaining and microscopy in combination with dye injection studies were used to characterize these vessels. Each peritumoral red-colored vessel was found to consist of a triad of collecting lymphatic vessel, vein, and artery, that were all enlarged. Peritumoral veins and arteries were both functional, as detected by intravenous dye injection. The enlarged lymphatic vessels were functional in most mice by subcutaneous dye injection assay, however tumor growth sometimes blocked lymph drainage to regional lymph nodes. Large red-colored vessels also grew between benign papillomas or invasive squamous cell carcinomas and regional lymph nodes in chemical carcinogen-treated mice. Immunostaining of the red-colored vessels again identified the clustered growth of enlarged collecting lymphatics, veins, and arteries in the vicinity of these spontaneously arising tumors. Implanted and spontaneously arising tumors induce coordinate growth of blood and lymphatic vessel triads. Many of these vessel triads are enlarged over several cm distance between the tumor and regional lymph nodes. Lymphatic drainage was sometimes blocked in mice before lymph node metastasis was detected, suggesting that an unknown mechanism alters lymph drainage patterns before tumors reach draining lymph nodes

  14. Tumors induce coordinate growth of artery, vein, and lymphatic vessel triads.

    Science.gov (United States)

    Ruddell, Alanna; Croft, Alexandra; Kelly-Spratt, Karen; Furuya, Momoko; Kemp, Christopher J

    2014-05-21

    Tumors drive blood vessel growth to obtain oxygen and nutrients to support tumor expansion, and they also can induce lymphatic vessel growth to facilitate fluid drainage and metastasis. These processes have generally been studied separately, so that it is not known how peritumoral blood and lymphatic vessels grow relative to each other. The murine B16-F10 melanoma and chemically-induced squamous cell carcinoma models were employed to analyze large red-colored vessels growing between flank tumors and draining lymph nodes. Immunostaining and microscopy in combination with dye injection studies were used to characterize these vessels. Each peritumoral red-colored vessel was found to consist of a triad of collecting lymphatic vessel, vein, and artery, that were all enlarged. Peritumoral veins and arteries were both functional, as detected by intravenous dye injection. The enlarged lymphatic vessels were functional in most mice by subcutaneous dye injection assay, however tumor growth sometimes blocked lymph drainage to regional lymph nodes. Large red-colored vessels also grew between benign papillomas or invasive squamous cell carcinomas and regional lymph nodes in chemical carcinogen-treated mice. Immunostaining of the red-colored vessels again identified the clustered growth of enlarged collecting lymphatics, veins, and arteries in the vicinity of these spontaneously arising tumors. Implanted and spontaneously arising tumors induce coordinate growth of blood and lymphatic vessel triads. Many of these vessel triads are enlarged over several cm distance between the tumor and regional lymph nodes. Lymphatic drainage was sometimes blocked in mice before lymph node metastasis was detected, suggesting that an unknown mechanism alters lymph drainage patterns before tumors reach draining lymph nodes.

  15. Nanoparticle encapsulation in red blood cells enables blood-pool magnetic particle imaging hours after injection

    International Nuclear Information System (INIS)

    Rahmer, J; Gleich, B; Borgert, J; Antonelli, A; Sfara, C; Magnani, M; Tiemann, B; Weizenecker, J

    2013-01-01

    Magnetic particle imaging (MPI) is a new medical imaging approach that is based on the nonlinear magnetization response of super-paramagnetic iron oxide nanoparticles (SPIOs) injected into the blood stream. To date, real-time MPI of the bolus passage of an approved MRI SPIO contrast agent injected into the tail vein of living mice has been demonstrated. However, nanoparticles are rapidly removed from the blood stream by the mononuclear phagocyte system. Therefore, imaging applications for long-term monitoring require the repeated administration of bolus injections, which complicates quantitative comparisons due to the temporal variations in concentration. Encapsulation of SPIOs into red blood cells (RBCs) has been suggested to increase the blood circulation time of nanoparticles. This work presents first evidence that SPIO-loaded RBCs can be imaged in the blood pool of mice several hours after injection using MPI. This finding is supported by magnetic particle spectroscopy performed to quantify the iron concentration in blood samples extracted from the mice 3 and 24 h after injection of SPIO-loaded RBCs. Based on these results, new MPI applications can be envisioned, such as permanent 3D real-time visualization of the vessel tree during interventional procedures, bleeding monitoring after stroke, or long-term monitoring and treatment control of cardiovascular diseases. (paper)

  16. Closure system of a vessel made of prestressed concrete

    International Nuclear Information System (INIS)

    Audibert, Alain

    1974-01-01

    The present invention relates to removable plugs of prestressed concrete which can be fitted to every type of closed high pressure vessels and especially to the cylindrical vessels of nuclear reactors. The method involved permits the plug to be fitted to the vessel through both radial and axial prestress. In this purpose, said invention proposes removable prestress ribs fitted inside sheaths in the plug and extending throughout the upper part of the bearing surfaces of the plug, said ribs being regularly arranged along the generators of an hyperboloid of one sheet. Owing to this important feature, that is to say said inclination of the ribs in accordance with the generators of said hyperboloid, said rib inclination can be changed on requirement for each realization [fr

  17. Acute effects of intradialytic aerobic exercise on solute removal, blood gases and oxidative stress in patients with chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Joseane Böhm

    Full Text Available Abstract Introduction: Hemodialysis contributes to increased oxidative stress and induces transitory hypoxemia. Compartmentalization decreases the supply of solutes to the dialyzer during treatment. The aim of this study was to investigate the acute effects of intradialytic aerobic exercise on solute removal, blood gases and oxidative stress in patients with chronic kidney disease during a single hemodialysis session. Methods: Thirty patients were randomized to perform aerobic exercise with cycle ergometer for lower limbs during 30 minutes with intensity between 60-70% of maximal heart rate, or control group (CG. Blood samples were collected prior to and immediately after exercise or the equivalent time in CG. Analysis of blood and dialysate biochemistry as well as blood gases were performed. Mass removal and solute clearance were calculated. Oxidative stress was determined by lipid peroxidation and by the total antioxidant capacity. Results: Serum concentrations of solutes increased with exercise, but only phosphorus showed a significant elevation (p = 0.035. There were no significant changes in solute removal and in the acid-base balance. Both oxygen partial pressure and saturation increased with exercise (p = 0.035 and p = 0.024, respectivelly, which did not occur in the CG. The total antioxidant capacity decreased significantly (p = 0.027. Conclusion: The acute intradialytic aerobic exercise increased phosphorus serum concentration and decreased total antioxidant capacity, reversing hypoxemia resulting from hemodialysis. The intradialytic exercise did not change the blood acid-base balance and the removal of solutes.

  18. Acute effects of intradialytic aerobic exercise on solute removal, blood gases and oxidative stress in patients with chronic kidney disease.

    Science.gov (United States)

    Böhm, Joseane; Monteiro, Mariane Borba; Andrade, Francini Porcher; Veronese, Francisco Veríssimo; Thomé, Fernando Saldanha

    2017-01-01

    Hemodialysis contributes to increased oxidative stress and induces transitory hypoxemia. Compartmentalization decreases the supply of solutes to the dialyzer during treatment. The aim of this study was to investigate the acute effects of intradialytic aerobic exercise on solute removal, blood gases and oxidative stress in patients with chronic kidney disease during a single hemodialysis session. Thirty patients were randomized to perform aerobic exercise with cycle ergometer for lower limbs during 30 minutes with intensity between 60-70% of maximal heart rate, or control group (CG). Blood samples were collected prior to and immediately after exercise or the equivalent time in CG. Analysis of blood and dialysate biochemistry as well as blood gases were performed. Mass removal and solute clearance were calculated. Oxidative stress was determined by lipid peroxidation and by the total antioxidant capacity. Serum concentrations of solutes increased with exercise, but only phosphorus showed a significant elevation (p = 0.035). There were no significant changes in solute removal and in the acid-base balance. Both oxygen partial pressure and saturation increased with exercise (p = 0.035 and p = 0.024, respectivelly), which did not occur in the CG. The total antioxidant capacity decreased significantly (p = 0.027). The acute intradialytic aerobic exercise increased phosphorus serum concentration and decreased total antioxidant capacity, reversing hypoxemia resulting from hemodialysis. The intradialytic exercise did not change the blood acid-base balance and the removal of solutes.

  19. Role of arginase in vessel wall remodeling

    Directory of Open Access Journals (Sweden)

    William eDurante

    2013-05-01

    Full Text Available Arginase metabolizes the semi-essential amino acid L-arginine to L-ornithine and urea. There are two distinct isoforms of arginase, arginase I and II, which are encoded by separate genes and display differences in tissue distribution, subcellular localization, and molecular regulation. Blood vessels express both arginase I and II but their distribution appears to be cell-, vessel-, and species-specific. Both isoforms of arginase are induced by numerous pathologic stimuli and contribute to vascular cell dysfunction and vessel wall remodeling in several diseases. Clinical and experimental studies have documented increases in the expression and/or activity of arginase I or II in blood vessels following arterial injury and in pulmonary and arterial hypertension, aging, and atherosclerosis. Significantly, pharmacological inhibition or genetic ablation of arginase in animals ameliorates abnormalities in vascular cells and normalizes blood vessel architecture and function in all of these pathological states. The detrimental effect of arginase in vascular remodeling is attributable to its ability to stimulate vascular smooth muscle cell and endothelial cell proliferation, and collagen deposition by promoting the synthesis of polyamines and L-proline, respectively. In addition, arginase adversely impacts arterial remodeling by directing macrophages towards an inflammatory phenotype. Moreover, the proliferative, fibrotic, and inflammatory actions of arginase in the vasculature are further amplified by its capacity to inhibit nitric oxide synthesis by competing with nitric oxide synthase for substrate, L-arginine. Pharmacologic or molecular approaches targeting specific isoforms of arginase represent a promising strategy in treating obstructive fibroproliferative vascular disease.

  20. Vacuum distilling vessel

    Energy Technology Data Exchange (ETDEWEB)

    Reik, H

    1928-12-27

    Vacuum distilling vessel for mineral oil and the like, characterized by the ring-form or polyconal stiffeners arranged inside, suitably eccentric to the casing, being held at a distance from the casing by connecting members of such a height that in the resulting space if necessary can be arranged vapor-distributing pipes and a complete removal of the residue is possible.

  1. Evaluation of the antimicrobial removal device when used with the BACTEC blood culture system

    International Nuclear Information System (INIS)

    Strand, C.L.

    1982-01-01

    A study to determine the value of the Antimicrobial Removal Device (ARD) used in conjunction with radiometric detection of bacteremia using three media was conducted. During a 12-month period, 622 duplicate ARD/BACTEC blood-culture sets were collected. There were 88 positive cultures that yielded 68 pathogenic isolates and 28 probable contaminant isolates. When all patients were considered, 31 pathogenic isolates were detected by both systems, 25 pathogenic isolates were detected faster or only by the BACTEC system, and 12 pathogenic isolates were detected faster or only when the ARD was employed. This difference is statistically significant (P less than 0.05). Thus, the standard BACTEC blood-culture system using three different media was superior to the same BACTEC system using ARD-processed blood specimens. When only patients receiving antimicrobial therapy were considered, there were more pathogenic isolates detected from unprocessed blood than from blood processed in the ARD; however, this difference was not statistically significant. In conclusion, there appears to be no advantage to using the ARD system in conjunction with the three-bottle BACTEC blood-culture system

  2. Influence of promoting blood circulation to remove blood stasis combined with laparoscopy on serum MCP-1, RANTES, oxidative stress and hormones in infertile patients with endometriosis

    Directory of Open Access Journals (Sweden)

    Xiao-Sha Zhang

    2017-11-01

    Full Text Available Objective: To observe the influence of promoting blood circulation to remove blood stasis combined with laparoscopy on serum MCP-1, RANTES, oxidative stress and hormones in infertile patients with endometriosis. Methods: A total of 60 infertile patients with endometriosis were randomly divided into observation group (30 cases and control group (30 cases. Observation group: promoting blood circulation to remove blood stasis combined with laparoscopy; control group: patients were treated only by laparoscopy. Recording and comparing the levels of MCP-1, RANTES, oxidative stress and hormones before and after treatment. Results: (1 Before treatment, there was no statistically significant difference in the serum MCP-1, RANTES, AOPP, MDA, SOD, levels between the two groups. After treatment, compared with the same group before treatment, the serum RANTES, AOPP, MDA levels of the two groups were significantly lower, the serum SOD level of the two groups were significantly higher, and those levels of observation group were significantly better than the control group, there was significant difference between the two groups. (2 Before treatment, there was no statistically significant difference in the serum FSH, LH, E2, P, PRL levels between the two groups. After treatment, compared with the same group before treatment, the serum FSH, LH, P, PRL levels of the two groups were significantly higher, the serum E2 level of the two groups were significantly lower, and those levels of observation group were significantly better than the control group, there was significant difference between the two groups. Conclusion: Promoting blood circulation to remove blood stasis combined with laparoscopy for infertile patients with endometriosis can reduce the levels of serum MCP-1, RANTES, oxidative stress, hormones and be beneficial to protect their uterine function.

  3. Nanobubbles Form at Active Hydrophobic Spots on the Luminal Aspect of Blood Vessels: Consequences for Decompression Illness in Diving and Possible Implications for Autoimmune Disease—An Overview

    Directory of Open Access Journals (Sweden)

    Ran Arieli

    2017-08-01

    Full Text Available Decompression illness (DCI occurs following a reduction in ambient pressure. Decompression bubbles can expand and develop only from pre-existing gas micronuclei. The different hypotheses hitherto proposed regarding the nucleation and stabilization of gas micronuclei have never been validated. It is known that nanobubbles form spontaneously when a smooth hydrophobic surface is submerged in water containing dissolved gas. These nanobubbles may be the long sought-after gas micronuclei underlying decompression bubbles and DCI. We exposed hydrophobic and hydrophilic silicon wafers under water to hyperbaric pressure. After decompression, bubbles appeared on the hydrophobic but not the hydrophilic wafers. In a further series of experiments, we placed large ovine blood vessels in a cooled high pressure chamber at 1,000 kPa for about 20 h. Bubbles evolved at definite spots in all the types of blood vessels. These bubble-producing spots stained positive for lipids, and were henceforth termed “active hydrophobic spots” (AHS. The lung surfactant dipalmitoylphosphatidylcholine (DPPC, was found both in the plasma of the sheep and at the AHS. Bubbles detached from the blood vessel in pulsatile flow after reaching a mean diameter of ~1.0 mm. Bubble expansion was bi-phasic—a slow initiation phase which peaked 45 min after decompression, followed by fast diffusion-controlled growth. Many features of decompression from diving correlate with this finding of AHS on the blood vessels. (1 Variability between bubblers and non-bubblers. (2 An age-related effect and adaptation. (3 The increased risk of DCI on a second dive. (4 Symptoms of neurologic decompression sickness. (5 Preconditioning before a dive. (6 A bi-phasic mechanism of bubble expansion. (7 Increased bubble formation with depth. (8 Endothelial injury. (9 The presence of endothelial microparticles. Finally, constant contact between nanobubbles and plasma may result in distortion of proteins and their

  4. Low level arsenic promotes progressive inflammatory angiogenesis and liver blood vessel remodeling in mice

    International Nuclear Information System (INIS)

    Straub, Adam C.; Stolz, Donna B.; Vin, Harina; Ross, Mark A.; Soucy, Nicole V.; Klei, Linda R.; Barchowsky, Aaron

    2007-01-01

    The vascular effects of arsenic in drinking water are global health concerns contributing to human disease worldwide. Arsenic targets the endothelial cells lining blood vessels, and endothelial cell activation or dysfunction may underlie the pathogenesis of both arsenic-induced vascular diseases and arsenic-enhanced tumorigenesis. The purpose of the current studies was to demonstrate that exposing mice to drinking water containing environmentally relevant levels of arsenic promoted endothelial cell dysfunction and pathologic vascular remodeling. Increased angiogenesis, neovascularization, and inflammatory cell infiltration were observed in Matrigel plugs implanted in C57BL/6 mice following 5-week exposures to 5-500 ppb arsenic [Soucy, N.V., Mayka, D., Klei, L.R., Nemec, A.A., Bauer, J.A., Barchowsky, A., 2005. Neovascularization and angiogenic gene expression following chronic arsenic exposure in mice. Cardiovasc.Toxicol 5, 29-42]. Therefore, functional in vivo effects of arsenic on endothelial cell function and vessel remodeling in an endogenous vascular bed were investigated in the liver. Liver sinusoidal endothelial cells (LSEC) became progressively defenestrated and underwent capillarization to decrease vessel porosity following exposure to 250 ppb arsenic for 2 weeks. Sinusoidal expression of PECAM-1 and laminin-1 proteins, a hallmark of capillarization, was also increased by 2 weeks of exposure. LSEC caveolin-1 protein and caveolae expression were induced after 2 weeks of exposure indicating a compensatory change. Likewise, CD45/CD68-positive inflammatory cells did not accumulate in the livers until after LSEC porosity was decreased, indicating that inflammation is a consequence and not a cause of the arsenic-induced LSEC phenotype. The data demonstrate that the liver vasculature is an early target of pathogenic arsenic effects and that the mouse liver vasculature is a sensitive model for investigating vascular health effects of arsenic

  5. Pulsatile blood flow, shear force, energy dissipation and Murray's Law

    Directory of Open Access Journals (Sweden)

    Bengtsson Hans-Uno

    2006-08-01

    Full Text Available Abstract Background Murray's Law states that, when a parent blood vessel branches into daughter vessels, the cube of the radius of the parent vessel is equal to the sum of the cubes of the radii of daughter blood vessels. Murray derived this law by defining a cost function that is the sum of the energy cost of the blood in a vessel and the energy cost of pumping blood through the vessel. The cost is minimized when vessel radii are consistent with Murray's Law. This law has also been derived from the hypothesis that the shear force of moving blood on the inner walls of vessels is constant throughout the vascular system. However, this derivation, like Murray's earlier derivation, is based on the assumption of constant blood flow. Methods To determine the implications of the constant shear force hypothesis and to extend Murray's energy cost minimization to the pulsatile arterial system, a model of pulsatile flow in an elastic tube is analyzed. A new and exact solution for flow velocity, blood flow rate and shear force is derived. Results For medium and small arteries with pulsatile flow, Murray's energy minimization leads to Murray's Law. Furthermore, the hypothesis that the maximum shear force during the cycle of pulsatile flow is constant throughout the arterial system implies that Murray's Law is approximately true. The approximation is good for all but the largest vessels (aorta and its major branches of the arterial system. Conclusion A cellular mechanism that senses shear force at the inner wall of a blood vessel and triggers remodeling that increases the circumference of the wall when a shear force threshold is exceeded would result in the observed scaling of vessel radii described by Murray's Law.

  6. Radioactive liquid containing vessel

    International Nuclear Information System (INIS)

    Sakurada, Tetsuo; Kawamura, Hironobu.

    1993-01-01

    Cooling jackets are coiled around the outer circumference of a container vessel, and the outer circumference thereof is covered with a surrounding plate. A liquid of good conductivity (for example, water) is filled between the cooling jackets and the surrounding plate. A radioactive liquid is supplied to the container vessel passing through a supply pipe and discharged passing through a discharge pipe. Cooling water at high pressure is passed through the cooling water jackets in order to remove the heat generated from the radioactive liquid. Since cooling water at high pressure is thus passed through the coiled pipes, the wall thickness of the container vessel and the cooling water jackets can be reduced, thereby enabling to reduce the cost. Further, even if the radioactive liquid is leaked, there is no worry of contaminating cooling water, to prevent contamination. (I.N.)

  7. The influence of surrogate blood vessels on the impact response of a physical model of the brain.

    Science.gov (United States)

    Parnaik, Yednesh; Beillas, Philippe; Demetropoulos, Constantine K; Hardy, Warren N; Yang, King H; King, Albert I

    2004-11-01

    Cerebral blood vessels are an integral part of the brain and may play a role in the response of the brain to impact. The purpose of this study was to quantify the effects of surrogate vessels on the deformation patterns of a physical model of the brain under various impact conditions. Silicone gel and tubing were used as surrogates for brain tissue and blood vessels, respectively. Two aluminum cylinders representing a coronal section of the brain were constructed. One cylinder was filled with silicone gel only, and the other was filled with silicone gel and silicone tubing arranged in the radial direction in the peripheral region. An array of markers was embedded in the gel in both cylinders to facilitate strain calculation via high-speed video analysis. Both cylinders were simultaneously subjected to a combination of linear and angular acceleration using a two-segment pendulum. Marker motion was tracked, and maximum shear strain (MSS) and maximum principal strain (MPS) were calculated using markers clustered in groups of three. Four test series were conducted. Peak angular acceleration varied from 2,600 to 26,000 rad/s2, and peak angular speed varied from 17 to 29 rad/s. For a given impact condition, the test-to-test variation of these values was less than 5.5%. For all clusters, the peak MSS and peak MPS for both physical models were less than 26% and 32%, respectively. For 90% of the cluster locations, the absolute value of the difference in peak MSS and peak MPS between the physical models was 4% and 6%, respectively. In the physical model with tubing, strain tended to decrease in the periphery (near to the tubing), while it tended to increase toward the center (away from the tubing). Strain amplitudes were found to be sensitive to the peak angular speeds. In general, this study suggests that the vasculature could influence the deformation response of the brain.

  8. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Blood Clots Blood Clotting and Pregnancy Clots and Travel DVT Myths vs. Facts Blood Disorder Fact Sheets ... that occurs when a DVT breaks off and travels to the blood vessels of the lungs. DVT ...

  9. A confocal scanning laser ophthalmoscope for retinal vessel oximetry

    Science.gov (United States)

    Lompado, Arthur

    Measurement of a person's blood oxygen saturation has long been recognized as a useful metric for the characterizing ailments ranging from chronic respiratory disorders to acute, potentially life threatening, traumas. The ubiquity of oxygen saturation monitors in the medical field, including portable pulse oximeters and laboratory based CO-oximeters, is a testament to the importance of this technique. The work presented here documents the design, fabrication and development of a unique type of oxygen saturation monitor, a confocal scanning retinal vessel oximeter, with the potential to expand the usefulness of the present devices. A large part of the knowledge base required to construct the instrument comes from the consideration of light scattering by red blood cells in a blood vessel. Therefore, a substantial portion of this work is devoted to the process of light scattering by whole human blood and its effects on the development of a more accurate oximeter. This light scattering effect has been both measured and modeled stochastically to determine its contribution to the measured oximeter signal. It is shown that, although well accepted in the published literature, the model only correlates marginally to the measurements due to inherent limitations imposed by the model assumptions. Nonetheless, enough material has been learned about the scattering to allow development of a mathematical model for the interaction of light with blood in a vessel, and this knowledge has been applied to the data reduction of the present oximeter. This data reduction technique has been tested in a controlled experiment employing a model eye with a blood filled mock retinal vessel. It will be shown that the presently developed technique exhibited strong correlation between the known blood oxygen saturation and that calculated by the new system.

  10. WE-E-18A-10: Comparison of Patient Dose and Vessel Visibility Between Antiscatter Grid Removal and Lower Angiographic Radiation Dose Settings for Pediatric Imaging: A Preclinical Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, K; Nachabe, R; Racadio, J [Children' s Hospital Medical Center, Cincinnati, OH (United States)

    2014-06-15

    Purpose: To define an alternative to antiscatter grid (ASG) removal in angiographic systems which achieves similar patient dose reduction as ASG removal without degrading image quality during pediatric imaging. Methods: This study was approved by the local institution animal care and use committee (IACUC). Six different digital subtraction angiography settings were evaluated that altered the mAs, (100, 70, 50, 35, 25, 17.5% of reference mAs) with and without ASG. Three pigs of 5, 15, and 20 kg (9, 15, and 17 cm abdominal thickness; smaller than a newborn, average 3 yr old, and average 10 year old human abdomen respectively) were imaged using the six dose settings with and without ASG. Image quality was defined as the order of vessel branch that is visible relative to the injected vessel. Five interventional radiologists evaluated all images. Image quality and patient dose were statistically compared using analysis of variance and receiver operating curve (ROC) analysis to define the preferred dose level and use of ASG for a minimum visibility of 2nd or 3rd order branches of vessel visibility. Results: ASG grid removal reduces dose by 26% with reduced image quality. Only with the ASG present can 3rd order branches be visualized; 100% mAs is required for 9 cm pig while 70% mAs is adequate for the larger pigs. 2nd order branches can be visualized with ASG at 17.5% mAs for all three pig sizes. Without the ASG, 50%, 35% and 35% mAs is required for smallest to largest pig. Conclusion: Removing ASG reduces patient dose and image quality. Image quality can be improved with the ASG present while further reducing patient dose if an optimized radiographic technique is used. Rami Nachabe is an employee of Philips Health Care; Keith Strauss is a paid consultant of Philips Health Care.

  11. Analytical prediction of the heat transfer from a blood vessel near the skin surface when cooled by a symmetrical cooling strip

    Science.gov (United States)

    Chato, J. C.; Shitzer, A.

    1971-01-01

    An analytical method was developed to estimate the amount of heat extracted from an artery running close to the skin surface which is cooled in a symmetrical fashion by a cooling strip. The results indicate that the optimum width of a cooling strip is approximately three times the depth to the centerline of the artery. The heat extracted from an artery with such a strip is about 0.9 w/m-C which is too small to affect significantly the temperature of the blood flow through a main blood vessel, such as the carotid artery. The method is applicable to veins as well.

  12. Agmatine Modulation of Noradrenergic Neurotransmission in Isolated Rat Blood Vessels.

    Science.gov (United States)

    Török, Jozef; Zemančíková, Anna

    2016-06-30

    Agmatine, a vasoactive metabolite of L-arginine, is widely distributed in mammalian tissues including blood vessels. Agmatine binding to imidazoline and α₂-adrenoceptors induces a variety of physiological and pharmacological effects. We investigated the effect of agmatine on contractile responses of the rat pulmonary artery and portal vein induced by electrical stimulation of perivascular nerves and by exogenous adrenergic substances. Experiments were performed on isolated segments of rat main pulmonary artery and its extralobular branches, and portal vein suspended in organ bath containing modified Krebs bicarbonate solution and connected to a force-displacement transducer for isometric tension recording. Electrical field stimulation (EFS) produced tetrodotoxin-sensitive contractile responses of pulmonary artery and portal vein. Besides the well known vasorelaxant actions, we found that agmatine also produced a concentration-dependent inhibition of neurogenic contractions induced by EFS in pulmonary arteries; however, the agmatine treatment did not influence the responses to exogenous noradrenaline. The inhibitory effect on EFS-induced contractions was not abolished by the α₂-adrenoceptor antagonist rauwolscine. In portal vein, in contrast, agmatine increased spontaneous mechanical contractions and enhanced the contractions induced by EFS. The results suggest that agmatine can significantly influence vascular function of pulmonary arteries and portal veins by modulating sympathetically mediated vascular contractions by pre- and postsynaptic mechanisms.

  13. An experimental study on feasibility of ex-vessel cooling through the external guide vessel

    International Nuclear Information System (INIS)

    Kang, Kyoung-Ho; Kim, Jong-Hwan; Park, Rae-Jun; Kim, Sang-Baik

    2000-01-01

    This paper presents the results of a series of experiments for assessing the efficacy of ex-vessel cooling through the external guide vessel during a severe accident. Four tests were performed in the LAVA test facility at KAERI, varying the boundary conditions at the outer surface of the vessel. The first test was a dry condition test conducted without cooling the outside of the vessel. On the other hand, in the second test, the cooling of the vessel surface was produced by gravity-driven forced injection of water along the annular gap of 25 mm between the vessel and the external guide vessel. Water flow rate was about 0.85 kg/s and total mass of available water was 300 kg. For the evaluation of the water flow rate effect, the third test was performed with a pool type cooling in the annulus without any circulation of water. These two external cooling tests were performed under elevated pressure of about 1.6 MPa. Finally, the fourth test was conducted under atmospheric pressure to evaluate the effect of system pressure on boiling heat transfer characteristics. In the dry test and the pool type ex-vessel cooling test performed under atmospheric pressure, the vessel was failed by a melt penetration at about 40 degree upper position from the vessel bottom, which is coincident with the boundary of the Al 2 O 3 /Fe melt separated layers. On the other hand, in both of the ex-vessel cooling tests conducted under elevated pressure of about 1.6 MPa, the vessel didn't fail. Compared with the pool boiling test, the vessel experienced effective cooling due to the inlet flow in the forced flow test. Synthesized the results of the tests, it was shown that the heat removal with ex-vessel cooling through the guide vessel is feasible, but the additional evaluations should be performed to guarantee enough thermal margin. (author)

  14. Retinal blood vessel segmentation in high resolution fundus photographs using automated feature parameter estimation

    Science.gov (United States)

    Orlando, José Ignacio; Fracchia, Marcos; del Río, Valeria; del Fresno, Mariana

    2017-11-01

    Several ophthalmological and systemic diseases are manifested through pathological changes in the properties and the distribution of the retinal blood vessels. The characterization of such alterations requires the segmentation of the vasculature, which is a tedious and time-consuming task that is infeasible to be performed manually. Numerous attempts have been made to propose automated methods for segmenting the retinal vasculature from fundus photographs, although their application in real clinical scenarios is usually limited by their ability to deal with images taken at different resolutions. This is likely due to the large number of parameters that have to be properly calibrated according to each image scale. In this paper we propose to apply a novel strategy for automated feature parameter estimation, combined with a vessel segmentation method based on fully connected conditional random fields. The estimation model is learned by linear regression from structural properties of the images and known optimal configurations, that were previously obtained for low resolution data sets. Our experiments in high resolution images show that this approach is able to estimate appropriate configurations that are suitable for performing the segmentation task without requiring to re-engineer parameters. Furthermore, our combined approach reported state of the art performance on the benchmark data set HRF, as measured in terms of the F1-score and the Matthews correlation coefficient.

  15. Renal blood flow and oxygenation drive nephron progenitor differentiation.

    Science.gov (United States)

    Rymer, Christopher; Paredes, Jose; Halt, Kimmo; Schaefer, Caitlin; Wiersch, John; Zhang, Guangfeng; Potoka, Douglas; Vainio, Seppo; Gittes, George K; Bates, Carlton M; Sims-Lucas, Sunder

    2014-08-01

    During kidney development, the vasculature develops via both angiogenesis (branching from major vessels) and vasculogenesis (de novo vessel formation). The formation and perfusion of renal blood vessels are vastly understudied. In the present study, we investigated the regulatory role of renal blood flow and O2 concentration on nephron progenitor differentiation during ontogeny. To elucidate the presence of blood flow, ultrasound-guided intracardiac microinjection was performed, and FITC-tagged tomato lectin was perfused through the embryo. Kidneys were costained for the vasculature, ureteric epithelium, nephron progenitors, and nephron structures. We also analyzed nephron differentiation in normoxia compared with hypoxia. At embryonic day 13.5 (E13.5), the major vascular branches were perfused; however, smaller-caliber peripheral vessels remained unperfused. By E15.5, peripheral vessels started to be perfused as well as glomeruli. While the interior kidney vessels were perfused, the peripheral vessels (nephrogenic zone) remained unperfused. Directly adjacent and internal to the nephrogenic zone, we found differentiated nephron structures surrounded and infiltrated by perfused vessels. Furthermore, we determined that at low O2 concentration, little nephron progenitor differentiation was observed; at higher O2 concentrations, more differentiation of the nephron progenitors was induced. The formation of the developing renal vessels occurs before the onset of blood flow. Furthermore, renal blood flow and oxygenation are critical for nephron progenitor differentiation. Copyright © 2014 the American Physiological Society.

  16. Cannulation and continuous cross-sectional area measurement of small blood vessels

    NARCIS (Netherlands)

    VanBavel, E.; Mooij, T.; Giezeman, M. J.; Spaan, J. A.

    1990-01-01

    Techniques have been developed for the study of isolated small arteries. To pressurize and perfuse segments of these vessels, a cannula with a low resistance to flow was developed. This cannula consisted of two concentric micropipettes. The end of a vessel segment was sucked into the inner pipette

  17. Theoretical modelling of physiologically stretched vessel in magnetisable stent assisted magnetic drug targeting application

    International Nuclear Information System (INIS)

    Mardinoglu, Adil; Cregg, P.J.; Murphy, Kieran; Curtin, Maurice; Prina-Mello, Adriele

    2011-01-01

    The magnetisable stent assisted magnetic targeted drug delivery system in a physiologically stretched vessel is considered theoretically. The changes in the mechanical behaviour of the vessel are analysed under the influence of mechanical forces generated by blood pressure. In this 2D mathematical model a ferromagnetic, coiled wire stent is implanted to aid collection of magnetic drug carrier particles in an elastic tube, which has similar mechanical properties to the blood vessel. A cyclic mechanical force is applied to the elastic tube to mimic the mechanical stress and strain of both the stent and vessel while in the body due to pulsatile blood circulation. The magnetic dipole-dipole and hydrodynamic interactions for multiple particles are included and agglomeration of particles is also modelled. The resulting collection efficiency of the mathematical model shows that the system performance can decrease by as much as 10% due to the effects of the pulsatile blood circulation. - Research highlights: →Theoretical modelling of magnetic drug targeting on a physiologically stretched stent-vessel system. →Cyclic mechanical force applied to mimic the mechanical stress and strain of both stent and vessel. →The magnetic dipole-dipole and hydrodynamic interactions for multiple particles is modelled. →Collection efficiency of the mathematical model is calculated for different physiological blood flow and magnetic field strength.

  18. Mural cell associated VEGF is required for organotypic vessel formation.

    Directory of Open Access Journals (Sweden)

    Lasse Evensen

    Full Text Available BACKGROUND: Blood vessels comprise endothelial cells, mural cells (pericytes/vascular smooth muscle cells and basement membrane. During angiogenesis, mural cells are recruited to sprouting endothelial cells and define a stabilizing context, comprising cell-cell contacts, secreted growth factors and extracellular matrix components, that drives vessel maturation and resistance to anti-angiogenic therapeutics. METHODS AND FINDINGS: To better understand the basis for mural cell regulation of angiogenesis, we conducted high content imaging analysis on a microtiter plate format in vitro organotypic blood vessel system comprising primary human endothelial cells co-cultured with primary human mural cells. We show that endothelial cells co-cultured with mural cells undergo an extensive series of phenotypic changes reflective of several facets of blood vessel formation and maturation: Loss of cell proliferation, pathfinding-like cell migration, branching morphogenesis, basement membrane extracellular matrix protein deposition, lumen formation, anastamosis and development of a stabilized capillary-like network. This phenotypic sequence required endothelial-mural cell-cell contact, mural cell-derived VEGF and endothelial VEGFR2 signaling. Inhibiting formation of adherens junctions or basement membrane structures abrogated network formation. Notably, inhibition of mural cell VEGF expression could not be rescued by exogenous VEGF. CONCLUSIONS: These results suggest a unique role for mural cell-associated VEGF in driving vessel formation and maturation.

  19. Characterization of Imidazoline Receptors in Blood Vessels for the Development of Antihypertensive Agents

    Directory of Open Access Journals (Sweden)

    Mei-Fen Chen

    2014-01-01

    Full Text Available It has been indicated that activation of peripheral imidazoline I2-receptor (I-2R may reduce the blood pressure in spontaneously hypertensive rats (SHRs. Also, guanidinium derivatives show the ability to activate imidazoline receptors. Thus, it is of special interest to characterize the I-2R using guanidinium derivatives in blood vessels for development of antihypertensive agent(s. Six guanidinium derivatives including agmatine, amiloride, aminoguanidine, allantoin, canavanine, and metformin were applied in this study. Western blot analysis was used for detecting the expression of imidazoline receptor in tissues of Wistar rats. The isometric tension of aortic rings isolated from male rats was also estimated. The expression of imidazoline receptor on rat aorta was identified. However, guanidinium derivatives for detection of aortic relaxation were not observed except agmatine and amiloride which induced a marked relaxation in isolated aortic rings precontracted with phenylephrine or KCl. Both relaxations induced by agmatine and amiloride were attenuated by glibenclamide at concentration enough to block ATP-sensitive potassium (KATP channels. Meanwhile, only agmatine-induced relaxation was abolished by BU224, a selective antagonist of imidazoline I2-receptors. Taken together, we suggest that agmatine can induce vascular relaxation through activation of peripheral imidazoline I2-receptor to open KATP channels. Thus, agmatine-like compound has the potential to develop as a new therapeutic agent for hypertension in the future.

  20. The removal of a malpositioned implant in the anterior mandible using piezosurgery.

    Science.gov (United States)

    Marini, Ettore; Cisterna, Veronica; Messina, Antonello Maria

    2013-05-01

    In oral, cranio, and maxillofacial surgery, a close relationship among the bone, nerves, and blood vessels can be regularly observed. Surgical procedures for the removal of dental implants have the potential to cause vascular injury and bleeding in the floor of the mouth and internal anterior region of the mandible. Furthermore, conventional osteotomy techniques always require extensive protection of adjacent soft tissue because cutting is not limited to bone and could easily affect other tissues when applied improperly. We report the removal by means of piezosurgery of a malpositioned osseointegrated implant that had previously caused a sublingual hematoma during its insertion. The postoperative course was uneventful, no bleeding, infection, or hematoma formation was noted and the patient reported 100% resolution of all symptoms. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Toxicity and removal efficiency of pharmaceutical metabolite clofibric acid by Typha spp.--potential use for phytoremediation?

    Science.gov (United States)

    Dordio, Ana V; Duarte, Cátia; Barreiros, Margarida; Carvalho, A J Palace; Pinto, A P; da Costa, Cristina Teixeira

    2009-02-01

    A study was conducted to assess Typha spp.'s ability to withstand and remove, from water, a metabolite of blood lipid regulator drugs, clofibric acid (CA). At a concentration of 20 microg L(-1), Typha had removed >50% of CA within the first 48h, reaching a maximum of 80% by the end of the assay. Experimental conditions assured that photodegradation, adsorption to vessel walls and microbial degradation did not contribute to the removal. Exposure to higher CA concentrations did not affect Typha's photosynthetic pigments but the overall increase in enzyme activity (ascorbate and guaiacol peroxidases, catalase, superoxide dismutase) indicates that both roots and leaves were affected by the xenobiotic. Eventually, Typha seemed able to cope with the CA's induced oxidative damage suggesting its ability for phytoremediation of CA contaminated waters.

  2. Effect of self-paced active recovery and passive recovery on blood lactate removal following a 200 m freestyle swimming trial

    Directory of Open Access Journals (Sweden)

    Mota MR

    2017-06-01

    Full Text Available Márcio Rabelo Mota,1,2 Renata Aparecida Elias Dantas,1,2 Iransé Oliveira-Silva,2 Marcelo Magalhães Sales,2,3 Rafael da Costa Sotero,2 Patrícia Espíndola Mota Venâncio,2 Jairo Teixeira Júnior,2 Sandro Nobre Chaves,4 Filipe Dinato de Lima4 1College of Education and Health Sciences, University Center of Brasília – UniCEUB, Brasília, 2College of Physical Education, UniEVANGÉLICA, Anápolis, Goiás, 3College of Physical Education, Universidade Estadual de Goiás - UEG, Quirinópolis, Goiás, 4College of Physical Education, University of Brasília – UnB, Brasília, Brazil Purpose: The aim of this study was to investigate the effect of self-paced active recovery (AR and passive recovery (PR on blood lactate removal following a 200 m freestyle swimming trial. Patients and methods: Fourteen young swimmers (with a training frequency of 6–8 sessions per week performed two maximal 200 m freestyle trials followed by 15 minutes of different recovery methods, on separate days. Recovery was performed with 15 minutes of passive rest or 5 minutes of passive rest and 10 minutes of self-paced AR. Performance variables (trial velocity and time, recovery variables (distance covered and AR velocity, and physiological variables (blood lactate production, blood lactate removal, and removal velocity were assessed and compared. Results: There was no difference between trial times in both conditions (PR: 125.86±7.92 s; AR: 125.71±8.21 s; p=0.752. AR velocity was 69.10±3.02% of 200 m freestyle trial velocity in AR. Blood lactate production was not different between conditions (PR: 8.82±2.47 mmol L−1; AR: 7.85±2.05 mmol L−1; p=0.069. However, blood lactate removal was higher in AR (PR: 1.76±1.70 mmol L−1; AR: 4.30±1.74 mmol L−1; p<0.001. The velocity of blood lactate removal was significantly higher in AR (PR: 0.18±0.17 mmol L−1 min−1; AR: 0.43±0.17 mmol L−1 min−1; p<0.001. Conclusion: Self-paced AR shows a higher velocity of blood

  3. The Physics of Coronary Blood Flow

    CERN Document Server

    Zamir, M

    2005-01-01

    Coronary blood flow is blood flow to the heart for its own metabolic needs. In the most common form of heart disease there is a disruption in this flow because of obstructive disease in the vessels that carry the flow. The subject of coronary blood flow is therefore associated mostly with the pathophysiology of this disease, rarely with dynamics or physics. Yet, the system responsible for coronary blood flow, namely the "coronary circulation," is a highly sophisticated dynamical system in which the dynamics and physics of the flow are as important as the integrity of the conducting vessels. While an obstruction in the conducting vessels is a fairly obvious and clearly visible cause of disruption in coronary blood flow, any discord in the complex dynamics of the system can cause an equally grave, though less conspicuous, disruption in the flow. This book is devoted specifically to the dynamics and physics of coronary blood flow. While relevance to the clinical and pathophysiological issues is clearly maintaine...

  4. Mutation of p107 exacerbates the consequences of Rb loss in embryonic tissues and causes cardiac and blood vessel defects.

    Science.gov (United States)

    Berman, Seth D; West, Julie C; Danielian, Paul S; Caron, Alicia M; Stone, James R; Lees, Jacqueline A

    2009-09-01

    The retinoblastoma tumor-suppressor protein, pRb, is a member of the pocket protein family that includes p107 and p130. These proteins have well-defined roles in regulating entry into and exit from the cell cycle and also have cell cycle-independent roles in facilitating differentiation. Here we investigate the overlap between pocket protein's function during embryonic development by using conditional mutant alleles to generate Rb;p107 double-mutant embryos (DKOs) that develop in the absence of placental defects. These DKOs die between e13.5 and e14.5, much earlier than either the conditional Rb or the germline p107 single mutants, which survive to birth or are largely viable, respectively. Analyses of the e13.5 DKOs shows that p107 mutation exacerbates the phenotypes resulting from pRb loss in the central nervous system and lens, but not in the peripheral nervous system. In addition, these embryos exhibit novel phenotypes, including increased proliferation of blood vessel endothelial cells, and heart defects, including double-outlet right ventricle (DORV). The DORV is caused, at least in part, by a defect in blood vessel endothelial cells and/or heart mesenchymal cells. These findings demonstrate novel, overlapping functions for pRb and p107 in numerous murine tissues.

  5. Dual energy CT of the peripheral arteries. A phantom study to assess the effect of automatic plaque removal on stenosis grading

    Energy Technology Data Exchange (ETDEWEB)

    Werncke, T.; Wolf, K.J.; Meyer, B.C. [Charite Universitaetsmedizin Berlin (Germany). Klinik und Hochschulambulanz fuer Radiologie und Nuklearmedizin; Albrecht, T. [Institut fuer Radiologie und Interventionelle Therapie, Vivantes, Neukoelln (Germany)

    2010-08-15

    Purpose: To evaluate the accuracy of dual energy (DE)-based plaque removal in a vessel phantom. Materials and Methods: Acrylic vessel phantoms of different diameters (3, 5, 8 mm), degrees of stenoses (25 - 100 %) and plaque densities (300 - 750 HU) were filled with contrast-enhanced blood (150 - 450 HU). Dual source CT was used for simultaneous image acquisition at 80 and 140 kV. Beside a DE-based plaque-subtracted dataset (DE-PS), a virtual 120 kV non-plaque subtracted dataset (N-PS) was generated. Agreement between the known and measured luminal diameter in both datasets was determined using Lin's concordance correlation coefficient (KLin). Results: A total of 8260 measurements were taken. The correlation of measured diameter in DE-PS images was excellent (KLin = 0.83 - 0.96) for 5 - 8 mm vessel phantoms with high luminal enhancement (300 - 450 HU) and plaque density (500 - 750 HU), moderate (KLin = 0.6 - 0.67) for 5 mm vessels with lower luminal enhancement and plaque density and poor (KLin = 0.10 - 0.64) in the 3 mm vessels. The correlation of N-PS-based stenosis quantification was excellent (KLin = 0.86 - 0.99) for 5 - 8 mm vessel phantoms if the contrast between lumen and plaque was above 100 HU. The correlation decreased in 3 mm vessels (KLin = 0.45 - 0.93), while the lowest correlation was observed for the lowest contrast between plaque and vessel lumen. Conclusion: Automatic DE-based plaque removal is highly effective for heavily calcified plaques and high luminal enhancement in larger diameter vessels {>=} 5 mm. However, accuracy is limited for low density calcified plaque, lower luminal enhancement and smaller caliber vessels mainly due to poor specificity. (orig.)

  6. Orthostatic leg blood volume changes assessed by near-infrared spectroscopy

    DEFF Research Database (Denmark)

    Truijen, J; Kim, Y S; Krediet, C T P

    2012-01-01

    posture, volume accumulation in small blood vessels contributes significantly to the total fluid volume accumulated in the legs. Considering that near-infrared spectroscopy (NIRS) tracks postural blood volume changes within the small blood vessels of the lower leg, we evaluated the NIRS-determined changes......-linear accumulation of blood volume in the small vessels of the leg, with an initial fast phase followed by a more gradual increase at least partly contributing to the relocation of fluid during orthostatic stress....

  7. Metallurgy of steels for PWR pressure vessels

    International Nuclear Information System (INIS)

    Kepka, M.; Mocek, J.; Barackova, L.

    1980-01-01

    A survey and the chemical compositions are presented of reactor pressure vessel steels. The metallurgy is described of steel making for pressure vessels in Japan and the USSR. Both acidic and alkaline open-hearth steel is used for the manufacture of ingots. The leading world manufacturers of forging ingots for pressure vessels, however, exclusively use electric steel. Vacuum casting techniques are exclusively used. Experience is shown gained with the introduction of the manufacture of forging ingots for pressure vessels at SKODA, Plzen. The metallurgical procedure was tested utilizing alkaline open hearths, electric arc furnaces and facilities for vacuum casting of steel. Pure charge raw materials should be used for securing high steel purity. Prior to forging pressure vessel rings, not only should sufficiently big bottoms and heads be removed but also the ingot middle part should be scrapped showing higher contents of impurities and nonhomogeneous structure. (B.S.)

  8. Metallurgy of steels for PWR pressure vessels

    Energy Technology Data Exchange (ETDEWEB)

    Kepka, M; Mocek, J; Barackova, L [Skoda, Plzen (Czechoslovakia)

    1980-09-01

    A survey and the chemical compositions are presented of reactor pressure vessel steels. The metallurgy is described of steel making for pressure vessels in Japan and the USSR. Both acidic and alkaline open-hearth steel is used for the manufacture of ingots. The leading world manufacturers of forging ingots for pressure vessels, however, exclusively use electric steel. Vacuum casting techniques are exclusively used. Experience is shown gained with the introduction of the manufacture of forging ingots for pressure vessels at SKODA, Plzen. The metallurgical procedure was tested utilizing alkaline open hearths, electric arc furnaces and facilities for vacuum casting of steel. Pure charge raw materials should be used for securing high steel purity. Prior to forging pressure vessel rings, not only should sufficiently big bottoms and heads be removed but also the ingot middle part should be scrapped showing higher contents of impurities and nonhomogeneous structure.

  9. Knockdown of Zebrafish Blood Vessel Epicardial Substance Results in Incomplete Retinal Lamination

    Directory of Open Access Journals (Sweden)

    Yu-Ching Wu

    2014-01-01

    Full Text Available Cell polarity during eye development determines the normal retinal lamination and differentiation of photoreceptor cells in the retina. In vertebrates, blood vessel epicardial substance (Bves is known to play an important role in the formation and maintenance of the tight junctions essential for epithelial cell polarity. In the current study, we generated a transgenic zebrafish Bves (zbves promoter-EGFP zebrafish line to investigate the expression pattern of Bves in the retina and to study the role of zbves in retinal lamination. Immunostaining with different specific antibodies from retinal cells and transmission electron microscopy were used to identify the morphological defects in normal and Bves knockdown zebrafish. In normal zebrafish, Bves is located at the apical junctions of embryonic retinal neuroepithelia during retinogenesis; later, it is strongly expressed around inner plexiform layer (IPL and retinal pigment epithelium (RPE. In contrast, a loss of normal retinal lamination and cellular polarity was found with undifferentiated photoreceptor cells in Bves knockdown zebrafish. Herein, our results indicated that disruption of Bves will result in a loss of normal retinal lamination.

  10. Involvement of calcitonin gene-related peptide in migraine: regional cerebral blood flow and blood flow velocity in migraine patients

    DEFF Research Database (Denmark)

    Lassen, L.H.; Jacobsen, V.B.; Haderslev, P.A.

    2008-01-01

    Calcitonin gene-related peptide (CGRP)-containing nerves are closely associated with cranial blood vessels. CGRP is the most potent vasodilator known in isolated cerebral blood vessels. CGRP can induce migraine attacks, and two selective CGRP receptor antagonists are effective in the treatment...

  11. Vessel co-option in primary human tumors and metastases: an obstacle to effective anti-angiogenic treatment?

    Science.gov (United States)

    Donnem, Tom; Hu, Jiangting; Ferguson, Mary; Adighibe, Omanma; Snell, Cameron; Harris, Adrian L; Gatter, Kevin C; Pezzella, Francesco

    2013-08-01

    Angiogenesis has been regarded as essential for tumor growth and progression. Studies of many human tumors, however, suggest that their microcirculation may be provided by nonsprouting vessels and that a variety of tumors can grow and metastasize without angiogenesis. Vessel co-option, where tumor cells migrate along the preexisting vessels of the host organ, is regarded as an alternative tumor blood supply. Vessel co-option may occur in many malignancies, but so far mostly reported in highly vascularized tissues such as brain, lung, and liver. In primary and metastatic lung cancer and liver metastasis from different primary origins, as much as 10-30% of the tumors are reported to use this alternative blood supply. In addition, vessel co-option is introduced as a potential explanation of antiangiogenic drug resistance, although the impact of vessel co-option in this clinical setting is still to be further explored. In this review we discuss tumor vessel co-option with specific examples of vessel co-option in primary and secondary tumors and a consideration of the clinical implications of this alternative tumor blood supply.

  12. Tumor vessel normalization after aerobic exercise enhances chemotherapeutic efficacy.

    Science.gov (United States)

    Schadler, Keri L; Thomas, Nicholas J; Galie, Peter A; Bhang, Dong Ha; Roby, Kerry C; Addai, Prince; Till, Jacob E; Sturgeon, Kathleen; Zaslavsky, Alexander; Chen, Christopher S; Ryeom, Sandra

    2016-10-04

    Targeted therapies aimed at tumor vasculature are utilized in combination with chemotherapy to improve drug delivery and efficacy after tumor vascular normalization. Tumor vessels are highly disorganized with disrupted blood flow impeding drug delivery to cancer cells. Although pharmacologic anti-angiogenic therapy can remodel and normalize tumor vessels, there is a limited window of efficacy and these drugs are associated with severe side effects necessitating alternatives for vascular normalization. Recently, moderate aerobic exercise has been shown to induce vascular normalization in mouse models. Here, we provide a mechanistic explanation for the tumor vascular normalization induced by exercise. Shear stress, the mechanical stimuli exerted on endothelial cells by blood flow, modulates vascular integrity. Increasing vascular shear stress through aerobic exercise can alter and remodel blood vessels in normal tissues. Our data in mouse models indicate that activation of calcineurin-NFAT-TSP1 signaling in endothelial cells plays a critical role in exercise-induced shear stress mediated tumor vessel remodeling. We show that moderate aerobic exercise with chemotherapy caused a significantly greater decrease in tumor growth than chemotherapy alone through improved chemotherapy delivery after tumor vascular normalization. Our work suggests that the vascular normalizing effects of aerobic exercise can be an effective chemotherapy adjuvant.

  13. A new resorbable device for ligation of blood vessels - A pilot study

    Directory of Open Access Journals (Sweden)

    Borg Niklas

    2011-07-01

    Full Text Available Abstract Background During surgery, controlled haemostasis to prevent blood loss is vital for a successful outcome. It can be difficult to ligate vessels located deep in the abdomen. A device that is easy to use and enables secure ligatures could be beneficial. Cable ties made of nylon have been used for ligation but the non-resorbable material caused tissue reactions. The objective of this study was to use a resorbable material to construct a device with a self-locking mechanism and to test its mechanical strength and ligation efficiency. Methods The device was manufactured by injection moulding of polydioxanone, a resorbable polymer used for suture materials. Polydioxanone with inherent viscosities of 1.9 dL/g and 1.3 dL/g were tested. The device consisted of a perforated flexible band which could be pulled through a case with a locking mechanism. After a first version of the device had been tested, some improvements were made. The locking case was downsized, corners were rounded off, the band was made thicker and the mould was redesigned to produce longer devices. Tensile tests were performed with the second version. The first version of the device was used to ligate the ovarian pedicle in a euthanized dog and to test echogenicity of the device with ultrasound. Compression of vessels of the ovarian pedicle was examined by histology. Both versions of the device were tested for haemostasis of and tissue grip on renal arteries in six anaesthetised pigs. Results The tensile strength of the flexible band of the devices with inherent viscosity of 1.9 dL/g was 50.1 ± 5.5 N (range 35.2-62.9 N, n = 11 and the devices with inherent viscosity of 1.3 dL/g had a tensile strength of 39.8 ± 8.1 N (range 18.6-54.2 N, n = 11. Injection moulding of the polymer with lower inherent viscosity resulted in a longer flow distance. Both versions of the device had an effective tissue grip and complete haemostasis of renal arteries was verified. The device attached

  14. Streaming flow from ultrasound contrast agents by acoustic waves in a blood vessel model.

    Science.gov (United States)

    Cho, Eunjin; Chung, Sang Kug; Rhee, Kyehan

    2015-09-01

    To elucidate the effects of streaming flow on ultrasound contrast agent (UCA)-assisted drug delivery, streaming velocity fields from sonicated UCA microbubbles were measured using particle image velocimetry (PIV) in a blood vessel model. At the beginning of ultrasound sonication, the UCA bubbles formed clusters and translated in the direction of the ultrasound field. Bubble cluster formation and translation were faster with 2.25MHz sonication, a frequency close to the resonance frequency of the UCA. Translation of bubble clusters induced streaming jet flow that impinged on the vessel wall, forming symmetric vortices. The maximum streaming velocity was about 60mm/s at 2.25MHz and decreased to 15mm/s at 1.0MHz for the same acoustic pressure amplitude. The effect of the ultrasound frequency on wall shear stress was more noticeable. Maximum wall shear stress decreased from 0.84 to 0.1Pa as the ultrasound frequency decreased from 2.25 to 1.0MHz. The maximum spatial gradient of the wall shear stress also decreased from 1.0 to 0.1Pa/mm. This study showed that streaming flow was induced by bubble cluster formation and translation and was stronger upon sonication by an acoustic wave with a frequency near the UCA resonance frequency. Therefore, the secondary radiant force, which is much stronger at the resonance frequency, should play an important role in UCA-assisted drug delivery. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Apparatus and method for removing solvent from carbon dioxide in resin recycling system

    Science.gov (United States)

    Bohnert, George W [Harrisonville, MO; Hand, Thomas E [Lee's Summit, MO; DeLaurentiis, Gary M [Jamestown, CA

    2009-01-06

    A two-step resin recycling system and method solvent that produces essentially contaminant-free synthetic resin material. The system and method includes one or more solvent wash vessels to expose resin particles to a solvent, the solvent contacting the resin particles in the one or more solvent wash vessels to substantially remove contaminants on the resin particles. A separator is provided to separate the solvent from the resin particles after removal from the one or more solvent wash vessels. The resin particles are next exposed to carbon dioxide in a closed loop carbon dioxide system. The closed loop system includes a carbon dioxide vessel where the carbon dioxide is exposed to the resin, substantially removing any residual solvent remaining on the resin particles after separation. A separation vessel is also provided to separate the solvent from the solvent laden carbon dioxide. Both the carbon dioxide and the solvent are reused after separation in the separation vessel.

  16. Neutron Assay System for Con?nement Vessel Disposition

    International Nuclear Information System (INIS)

    Frame, Katherine C.; Bourne, Mark M.; Crooks, William J.; Evans, Louise; Mayo, Douglas R.; Miko, David K.; Salazar, William R.; Stange, Sy; Valdez, Jose I.; Vigil, Georgiana M.

    2012-01-01

    Waste will be removed from confinement vessels remaining from 1970s-era experiments. Los Alamos has 9+ spherical confinement vessels remaining from experiments. Each vessel contains ∼ 500 lbs of radioactive debris such as actinide metals and oxides, metals, powdered silica, graphite, and wires and hardware. In order to dispose of the vessels, debris and contamination must be removed. Neutron assay system was designed to assay vessels before and after cleanout. System requirements are: (1) Modular and moveable; (2) Capable of detecting ∼100g 239 Pu equivalent in a 2-inch thick steel sphere with 6 foot diameter; and (3) Capable of safeguards-quality assays. Initial design parameters arethe use of 4-atm 3 He tubes with length of 6 feet, and 3 He tubes embedded in polyethelene for moderation. This paper describes the calibration of the Confinement Vessel Assay System (CVAS) and quantification of its uncertainties. Assay uncertainty depends on five factors: (1) Statistical uncertainty in the assay measurement; (2) Statistical uncertainty in the background measurement; (3) Statistical uncertainty in the isotopics determination - This should be much smaller than the other uncertainties; (4) Systematic uncertainty due to position bias; and (5) Systematic uncertainty due to fluctuations in cosmic ray spallation. This one can be virtually eliminated by performing the background measurement with an empty vessel - but that may not be possible. We used modeling and experiments to quantify the systematic uncertainties. The calibration assumes a uniform distribution of material, but reality will be different. MCNPX modeling was used to quantify the positional bias. The model was benchmarked to build confidence in its results. Material at top of vessel is 44% greater than amount assayed, according to singles. Material near 19-tube detector is 38% less than amount assayed, according to singles. Cosmic ray spallation contributes significantly to the background. Comparing rates

  17. Pressure vessel integrity and weld inspection procedure

    International Nuclear Information System (INIS)

    Solomon, K.A.; Okrent, D.; Kastenberg, W.E.

    1975-01-01

    The primary objective of this paper is to develop a simple methodology which, when coupled with existing observations on pressure vessel behavior, provides an inter-relation between pressure vessel integrity, and the parameters of the in-service inspection program, including inspection sample size, frequency and efficiency. A modified Markov process is employed and a computer code was written to obtain numerical results. The Markov process mathematically describes the following physical events. In a nuclear reactor pressure vessel weld, some defects may exist prior to the zeroth inspection (i.e., prior to vessel operation). During the zeroth inspection and repair processes, some of these defects are removed. During the first cycle of vessel operation, the existing defects may grow and some new defects may be generated. Those defects that are found at the first (and succeeding) inspection interval and warrant repair, are repaired. The above process continues through several operating cycles to the end of vessel life. During any inspection, only a portion of the welds may be inspected, and with less than perfect efficiency

  18. Sensing of Vascular Permeability in Inflamed Vessel of Live Animal

    Directory of Open Access Journals (Sweden)

    Sang A Park

    2018-01-01

    Full Text Available Increase in vascular permeability is a conclusive response in the progress of inflammation. Under controlled conditions, leukocytes are known to migrate across the vascular barriers to the sites of inflammation without severe vascular rupture. However, when inflammatory state becomes excessive, the leakage of blood components may occur and can be lethal. Basically, vascular permeability can be analyzed based on the intensity of blood outflow. To evaluate the amount and rate of leakage in live mice, we performed cremaster muscle exteriorization to visualize blood flow and neutrophil migration. Using two-photon intravital microscopy of the exteriorized cremaster muscle venules, we found that vascular barrier function is transiently and locally disrupted in the early stage of inflammatory condition induced by N-formylmethionyl-leucyl-phenylalanine (fMLP. Measurement of the concentration of intravenously (i.v. injected Texas Red dextran inside and outside the vessels resulted in clear visualization of real-time increases in transient and local vascular permeability increase in real-time manner. We successfully demonstrated repeated leakage from a target site on a blood vessel in association with increasing severity of inflammation. Therefore, compared to other methods, two-photon intravital microscopy more accurately visualizes and quantifies vascular permeability even in a small part of blood vessels in live animals in real time.

  19. [Telescopic adhesive anastomosis of small blood vessel applied in formation of arteriovenous fistula for hemodialysis].

    Science.gov (United States)

    Shen, G; Leng, Y; Rong, G

    1997-03-01

    The formation of an arteriovenous fistual for dialysis by routine interrupted sutures anastomosing the vein and artery is difficult to perform and time-consuming. A new method, telescopic adhesive anastomosis was studied and applied in 10 hemodialysis patients, who were in need of an arteriovenous fistula. The external diameter of the vessels anastomosed was 2.40 +/- 0.20 mm (radial artery) or 2.40 +/- 0.35 mm (cephalic vein). After thorough debridement of the vascular ends, the arterial end was put in the venous lumen. In order to fix the telescopic vessels, two stitches were applied 180 degrees apart from each other and tied. Each stitch was inserted from vein (penetrating the whole wall) to artery (just through the adventitia and partial thickness of the media vasorum). The distance from the stitch to the edge of the vein was 0.5 mm, and that of the artery was approximated to the external diameter of the vessle. The medical adhesive was then applied for sealing the anastomotic adventitia. Ten seconds were given for the solidification of the adhesive. The patients were followed up for 8 months. The patency rate was 100%, and the rate of blood flow was more than 300 ml/min (measured by ultrasonography). It was shown that this method could be managed easily and quickly, and the so-formed fistula would fulfill the need of hemodialysis.

  20. Application of radioisotope tracer techniques in evaluation of irradiation vessel of flue gas treatment system

    International Nuclear Information System (INIS)

    Joon-Ha Jin; Myun-Joo Lee; Sung-Hee Jung; Young-Chang Nho

    1998-01-01

    The proper design of the irradiation vessel of electron beam flue gases treatment plant and resultant optimum gas flow pattern is a very important factor to get a high removal efficiency of toxic materials from flue gases. Radioisotope tracer experiments were conducted to study the residence time distribution of gas flow in a cylindrical irradiation vessel. A few mCi of gaseous radioisotope tracer Ar-41 was injected to the upstream of the vessel and the input and output response were measured with two NaI scintillation detectors. The same experiment was conducted after the modification of the vessel by introducing 4 baffles. The experimental data were analyzed to calculate mean residence times and mixing characteristics of each system using the residence time distribution (RTD) analysis software. A method to estimate pollutant removal efficiencies of an irradiation vessel from the residence time distributions measured by radiotracer experiments was suggested. The analytical results were compared to evaluate the effect of the baffles on the removal efficiency of the plant

  1. Design evolution and integration of the ITER in-vessel components

    International Nuclear Information System (INIS)

    Martin, A.; Calcagno, B.; Chappuis, Ph.; Daly, E.; Dellopoulos, G.; Furmanek, A.; Gicquel, S.; Heitzenroeder, P.; Jiming, Chen; Kalish, M.; Kim, D.-H.; Khomiakov, S.; Labusov, A.; Loarte, A.; Loughlin, M.; Merola, M.; Mitteau, R.; Polunovski, E.; Raffray, R.; Sadakov, S.

    2013-01-01

    Highlights: ► The ITER in-vessel components have experienced a major redesign since the ITER Design Review of 2007. ► A set of in-vessel vertical stabilization (VS) coils and a set of in-vessel Edge Localized Mode (ELM) control coils have been implemented. ► The blanket system has been redesigned to include first wall (FW) shaping, to upgrade the FW heat removal capability and to allow for an “in situ” replacement. ► The blanket manifold system has been redesigned to improve leak detection and localisation. ► The introduction of a new set of in-vessel coils and the design evolution of the blanket system while the ITER project was entering the procurement phase have proven to be a major engineering challenge. -- Abstract: The ITER in-vessel components have experienced a major redesign since the ITER Design Review of 2007. A set of in-vessel vertical stabilization (VS) coils and a set of in-vessel Edge Localized Mode (ELM) control coils have been implemented. The blanket system has been redesigned to include first wall (FW) shaping, to upgrade the FW heat removal capability and to allow for an “in situ” replacement. The blanket manifold system has been redesigned to improve leak detection and localisation. The introduction of a new set of in-vessel coils and the design evolution of the blanket system while the ITER project was entering the procurement phase have proven to be a major engineering challenge. This paper describes the status of the redesign of the in-vessel components and the associated integration issues

  2. 33 CFR 157.170 - COW equipment: Removal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false COW equipment: Removal. 157.170... Crude Oil Washing (COW) System on Tank Vessels Cow Operations § 157.170 COW equipment: Removal. (a) Whenever a deck mounted COW machine is removed from the tank, the master shall ensure that: (1) The supply...

  3. In-vessel tritium retention and removal in ITER-FEAT

    International Nuclear Information System (INIS)

    Federici, G.; Brooks, J.N.; Iseli, M.; Wu, C.H.

    2001-01-01

    Erosion of the divertor and first-wall plasma-facing components, tritium uptake in the re-deposited films, and direct implantation in the armour material surfaces surrounding the plasma, represent crucial physical issues that affect the design of future fusion devices. In this paper we present the derivation, and discuss the results, of current predictions of tritium inventory in ITER-FEAT due to co-deposition and implantation and their attendant uncertainties. The current armour materials proposed for ITER-FEAT are beryllium on the first-wall, carbon-fibre-composites on the divertor plate near the separatrix strike points, to withstand the high thermal loads expected during off-normal events, e.g., disruption, and tungsten elsewhere in the divertor. Tritium co-deposition with chemically eroded carbon in the divertor, and possibly with some Be eroded from the first-wall, is expected to represent the dominant mechanism of in-vessel tritium retention in ITER-FEAT. This demands efficient in-situ methods of mitigation and retrieval to avoid frequent outages due to the reaching of precautionary operating limits set by safety considerations (e.g., ∝350 g of in-vessel co-deposited tritium) and for fuel economy reasons. Priority areas where further R and D work is required to narrow the remaining uncertainties are also briefly discussed. (orig.)

  4. In-vessel tritium retention and removal in ITER-FEAT

    Energy Technology Data Exchange (ETDEWEB)

    Federici, G. [ITER Garching Joint Work Site, Garching (Germany); Brooks, J.N. [Argonne National Lab., IL (United States); Iseli, M. [ITER Naka Joint Work Site, Naka-gun (Japan); Wu, C.H. [EFDA Close Support Unit, Garching (Germany)

    2001-07-01

    Erosion of the divertor and first-wall plasma-facing components, tritium uptake in the re-deposited films, and direct implantation in the armour material surfaces surrounding the plasma, represent crucial physical issues that affect the design of future fusion devices. In this paper we present the derivation, and discuss the results, of current predictions of tritium inventory in ITER-FEAT due to co-deposition and implantation and their attendant uncertainties. The current armour materials proposed for ITER-FEAT are beryllium on the first-wall, carbon-fibre-composites on the divertor plate near the separatrix strike points, to withstand the high thermal loads expected during off-normal events, e.g., disruption, and tungsten elsewhere in the divertor. Tritium co-deposition with chemically eroded carbon in the divertor, and possibly with some Be eroded from the first-wall, is expected to represent the dominant mechanism of in-vessel tritium retention in ITER-FEAT. This demands efficient in-situ methods of mitigation and retrieval to avoid frequent outages due to the reaching of precautionary operating limits set by safety considerations (e.g., {proportional_to}350 g of in-vessel co-deposited tritium) and for fuel economy reasons. Priority areas where further R and D work is required to narrow the remaining uncertainties are also briefly discussed. (orig.)

  5. In-Vessel Tritium Retention and Removal in ITER-FEAT

    Science.gov (United States)

    Federici, G.; Brooks, J. N.; Iseli, M.; Wu, C. H.

    Erosion of the divertor and first-wall plasma-facing components, tritium uptake in the re-deposited films, and direct implantation in the armour material surfaces surrounding the plasma, represent crucial physical issues that affect the design of future fusion devices. In this paper we present the derivation, and discuss the results, of current predictions of tritium inventory in ITER-FEAT due to co-deposition and implantation and their attendant uncertainties. The current armour materials proposed for ITER-FEAT are beryllium on the first-wall, carbon-fibre-composites on the divertor plate near the separatrix strike points, to withstand the high thermal loads expected during off-normal events, e.g., disruptions, and tungsten elsewhere in the divertor. Tritium co-deposition with chemically eroded carbon in the divertor, and possibly with some Be eroded from the first-wall, is expected to represent the dominant mechanism of in-vessel tritium retention in ITER-FEAT. This demands efficient in-situ methods of mitigation and retrieval to avoid frequent outages due to the reaching of precautionary operating limits set by safety considerations (e.g., ˜350 g of in-vessel co-deposited tritium) and for fuel economy reasons. Priority areas where further R&D work is required to narrow the remaining uncertainties are also briefly discussed.

  6. Blood flow determinations utilizing digital densitometry

    International Nuclear Information System (INIS)

    Lois, F.; Mankovich, N.J.; Gomes, A.S.

    1987-01-01

    A method of obtaining relative and absolute blood flow measurements from digital densitometry was evaluated with a simulated vessel phantom and a hydrodynamic model. A digital vascular imaging system capable of acquisition in 512 2 and 1024 2 mode was used. Relative and absolute blood flow were measured using parameters derived from the densitometric curve. Since application of densitometric data to absolute flow measurements requires the vessel diameter, an algorithm for vessel size determination was created. Gray scale changes were demonstrated to be linearly related to contrast concentration. The variance of vessel size determination was significantly different in all combinations of 1024 2 and 512 2 imaging with 15 cm or 35 cm field size. The error in vessel size determination was significantly less using the larger 1024 2 matrix and the smaller 15 cm image intensifier field size, as shown by the smaller variance. In relative flow determinations, there was good correlation between the flow and four parameters of the densitometric curve with no significant differences between 512 2 and 1024 2 imaging. Absolute flow determinations had slightly lower correlation to actual flow but were not significantly different from relative flow determinations. Relative and absolute blood flow determinations can be performed adequately with either 512 2 or 1024 2 imaging. The increased accuracy in vessel size determination with 1024 2 imaging makes this high resolution system potentially perferable to determine absolute blood flow. (orig.)

  7. Surface modifying of microporous PTFE capillary for bilirubin removing from human plasma and its blood compatibility

    International Nuclear Information System (INIS)

    Jin Gu; Yao Qizhi; Zhang Shanzi; Zhang Lei

    2008-01-01

    In this study, human serum albumin (HSA) was covalently immobilized onto the inner surface of microporous poly(tetrafluoroethylene) (MPTFE) capillaries for direct bilirubin removal from human plasma. To obtain active binding sites for HSA, the MPTFE capillaries were chemically functionalized by using a coating of poly(vinyl alcohol) (PVA)-glycidyl methacrylate (GMA) copolymers. Characterization of grafted MPTFE capillaries was verified by XPS, Fourier transform infrared spectroscopy (FT-IR), scanning electronic microscopy (SEM). Non-specific adsorption on the PVA-GMA coated capillary remains low (< 0.38 mg bilirubin/g), and higher affinity adsorption capacity, of up to 73.6 mg bilirubin/g polymer was obtained after HSA is immobilized. Blood compatibility of the grafted MPTFE capillary was evaluated by SEM and platelet rich plasma (PRP) contacting experiments. The experimental data on blood compatibility indicated that PVA-coated and PVA-GMA-HSA coated PTFE capillary showed a sharp suppress on platelets adhesion. The proposed method has the potential of serving in bilirubin removal in clinical application

  8. Inner ocular blood flow responses to an acute decrease in blood pressure in resting humans

    International Nuclear Information System (INIS)

    Ikemura, Tsukasa; Kashima, Hideaki; Yamaguchi, Yuji; Miyaji, Akane; Hayashi, Naoyuki

    2015-01-01

    Whether inner ocular vessels have an autoregulatory response to acute fluctuations in blood pressure is unclear. We tried to examine the validity of acute hypotension elicited by thigh-cuff release as to assess the dynamic autoregulation in the ocular circulation. Blood flow velocity in the superior nasal and inferior temporal retinal arterioles, and in the retinal and choroidal vasculature were measured with the aid of laser speckle flowgraphy before and immediately after an acute decrease in blood pressure in 20 healthy subjects. Acute hypotension was induced by a rapid release of bilateral thigh occlusion cuffs that had been inflated to 220 mmHg for 2 min. The ratio of the relative change in retinal and choroidal blood flow velocity to the relative change in mean arterial blood pressure (MAP) was calculated. Immediately after cuff release, the MAP and blood flows in the all ocular target vessels decreased significantly from the baseline values obtained before thigh-cuff release. The ratio of the relative change in inner ocular blood flow velocity to that in the MAP exceeded 1% / %mmHg. An explicit dynamic autoregulation in inner ocular vessels cannot be demonstrated in response to an acute hypotension induced by the thigh-cuff release technique. (paper)

  9. Erythropoietin-enhanced endothelial progenitor cell recruitment in peripheral blood and renal vessels during experimental acute kidney injury in rats.

    Science.gov (United States)

    Cakiroglu, Figen; Enders-Comberg, Sora Maria; Pagel, Horst; Rohwedel, Jürgen; Lehnert, Hendrik; Kramer, Jan

    2016-03-01

    Beneficial effects of erythropoietin (EPO) have been reported in acute kidney injury (AKI) when administered prior to induction of AKI. We studied the effects of EPO administration on renal function shortly after ischemic AKI. For this purpose, rats were subjected to renal ischemia for 30 min and EPO was administered at a concentration of 500 U/kg either i.v. as a single shot directly after ischemia or with an additional i.p. dose until 3 days after surgery. The results were compared with AKI rats without EPO application and a sham-operated group. Renal function was assessed by measurement of serum biochemical markers, histological grading, and using an isolated perfused kidney (IPK) model. Furthermore, we performed flow cytometry to analyze the concentration of endothelial progenitor cells (EPCs) in the peripheral blood and renal vessels. Following EPO application, there was only a statistically non-significant tendency of serum creatinine and urea to improve, particularly after daily EPO application. Renal vascular resistance and the renal perfusion rate were not significantly altered. In the histological analysis, acute tubular necrosis was only marginally ameliorated following EPO administration. In summary, we could not demonstrate a significant improvement in renal function when EPO was applied after AKI. Interestingly, however, EPO treatment resulted in a highly significant increase in CD133- and CD34-positive EPC both in the peripheral blood and renal vessels. © 2015 International Federation for Cell Biology.

  10. Effects of Blood Coagulate Removal Method on Aedes albopictus (Diptera: Culicidae) Life Table Characteristics and Vector Competence for Dengue Virus.

    Science.gov (United States)

    van Dodewaard, Caitlin A M; Richards, Stephanie L; Harris, Jonathan W

    2016-01-01

    Commercially available blood can be used as an alternative to live animals to maintain mosquito colonies and deliver infectious bloodmeals during research studies. We analyzed the extent to which two methods for blood coagulate removal (defibrination or addition of sodium citrate) affected life table characteristics (i.e., fecundity, fertility, hatch rate, and adult survival) and vector competence (infection, dissemination, and transmission) of Aedes albopictus (Skuse) for dengue virus (DENV). Two types of bovine blood were tested at two extrinsic incubation temperatures (27 or 30°C) for DENV-infected and uninfected mosquitoes. Fully engorged mosquitoes were transferred to individual cages containing an oviposition cup and a substrate. Eggs (fecundity) and hatched larvae (fertility) were counted. At 14 and 21 d post feeding on a DENV-infected bloodmeal, 15 mosquitoes were sampled from each group, and vector competence was analyzed (bodies [infection], legs [dissemination], and saliva [transmission]). Differences in life table characteristics and vector competence were analyzed for mosquitoes fed blood processed using different methods for removal of coagulates. The method for removal of coagulates significantly impacted fecundity, fertility, and hatch time in the uninfected group, but not DENV-infected group. Infected mosquitoes showed significantly higher fecundity and faster hatch time than uninfected mosquitoes. We show no significant differences in infection or dissemination rates between groups; however, horizontal transmission rate was significantly higher in mosquitoes fed DENV-infected citrated compared with defibrinated blood. We expect the findings of this study to inform research using artificial blood delivery methods to assess vector competence. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Revisiting the Logan plot to account for non-negligible blood volume in brain tissue.

    Science.gov (United States)

    Schain, Martin; Fazio, Patrik; Mrzljak, Ladislav; Amini, Nahid; Al-Tawil, Nabil; Fitzer-Attas, Cheryl; Bronzova, Juliana; Landwehrmeyer, Bernhard; Sampaio, Christina; Halldin, Christer; Varrone, Andrea

    2017-08-18

    Reference tissue-based quantification of brain PET data does not typically include correction for signal originating from blood vessels, which is known to result in biased outcome measures. The bias extent depends on the amount of radioactivity in the blood vessels. In this study, we seek to revisit the well-established Logan plot and derive alternative formulations that provide estimation of distribution volume ratios (DVRs) that are corrected for the signal originating from the vasculature. New expressions for the Logan plot based on arterial input function and reference tissue were derived, which included explicit terms for whole blood radioactivity. The new methods were evaluated using PET data acquired using [ 11 C]raclopride and [ 18 F]MNI-659. The two-tissue compartment model (2TCM), with which signal originating from blood can be explicitly modeled, was used as a gold standard. DVR values obtained for [ 11 C]raclopride using the either blood-based or reference tissue-based Logan plot were systematically underestimated compared to 2TCM, and for [ 18 F]MNI-659, a proportionality bias was observed, i.e., the bias varied across regions. The biases disappeared when optimal blood-signal correction was used for respective tracer, although for the case of [ 18 F]MNI-659 a small but systematic overestimation of DVR was still observed. The new method appears to remove the bias introduced due to absence of correction for blood volume in regular graphical analysis and can be considered in clinical studies. Further studies are however required to derive a generic mapping between plasma and whole-blood radioactivity levels.

  12. What is cerebral small vessel disease?

    International Nuclear Information System (INIS)

    Onodera, Osamu

    2011-01-01

    An accumulating amount of evidence suggests that the white matter hyperintensities on T 2 weighted brain magnetic resonance imaging predict an increased risk of dementia and gait disturbance. This state has been proposed as cerebral small vessel disease, including leukoaraiosis, Binswanger's disease, lacunar stroke and cerebral microbleeds. However, the concept of cerebral small vessel disease is still obscure. To understand the cerebral small vessel disease, the precise structure and function of cerebral small vessels must be clarified. Cerebral small vessels include several different arteries which have different anatomical structures and functions. Important functions of the cerebral small vessels are blood-brain barrier and perivasucular drainage of interstitial fluid from the brain parenchyma. Cerebral capillaries and glial endfeet, take an important role for these functions. However, the previous pathological investigations on cerebral small vessels have focused on larger arteries than capillaries. Therefore little is known about the pathology of capillaries in small vessel disease. The recent discoveries of genes which cause the cerebral small vessel disease indicate that the cerebral small vessel diseases are caused by a distinct molecular mechanism. One of the pathological findings in hereditary cerebral small vessel disease is the loss of smooth muscle cells, which is an also well-recognized finding in sporadic cerebral small vessel disease. Since pericytes have similar character with the smooth muscle cells, the pericytes should be investigated in these disorders. In addition, the loss of smooth muscle cells may result in dysfunction of drainage of interstitial fluid from capillaries. The precise correlation between the loss of smooth muscle cells and white matter disease is still unknown. However, the function that is specific to cerebral small vessel may be associated with the pathogenesis of cerebral small vessel disease. (author)

  13. Novel Computerized Method for Measurement of Retinal Vessel Diameters

    Directory of Open Access Journals (Sweden)

    Hichem Guedri

    2017-03-01

    Full Text Available Several clinical studies reveal the relationship between alterations in the topologies of the human retinal blood vessel, the outcrop and the disease evolution, such as diabetic retinopathy, hypertensive retinopathy, and macular degeneration. Indeed, the detection of these vascular changes always has gaps. In addition, the manual steps are slow, which may be subjected to a bias of the perceiver. However, we can overcome these troubles using computer algorithms that are quicker and more accurate. This paper presents and investigates a novel method for measuring the blood vessel diameter in the retinal image. The proposed method is based on a thresholding segmentation and thinning step, followed by the characteristic point determination step by the Douglas-Peucker algorithm. Thereafter, it uses the active contours to detect vessel contour. Finally, Heron’s Formula is applied to assure the calculation of vessel diameter. The obtained results for six sample images showed that the proposed method generated less errors compared to other techniques, which confirms the high performance of the proposed method.

  14. Monitoring Your Blood Sugar Level

    Science.gov (United States)

    ... and NutritionHealth Insurance: Understanding What It CoversHigh Homocysteine Level: How It Affects Your Blood VesselsUnderstanding Your Medical ... Health Resources Healthcare Management Monitoring Your Blood Sugar Level Monitoring Your Blood Sugar Level Share Print What ...

  15. Sensitivity analysis for maximum heat removal from debris in the lower head

    International Nuclear Information System (INIS)

    Kim, Yong Hoon; Suh, Kune Y.

    2000-01-01

    Sensitivity analyses were performed to determine the maximum heat removal capability from the debris and the reactor pressure vessel (RPV) wall through the gap that may be formed during a core melt relocation accident. Cases studied included four different nuclear power plant (TMI-2,KORI-2,YGN 3and4 and KNGR) per the thermal opower output. Results of the analysis show that the heat removal through gap cooling relative to flooding is efficacious as much as about 40% of the core material accumulated in the lower plenum in case of the TMI-2 reactor. In excess of 40%, however, the gap cooling alone was found not to be enough for heat removal from the core debris. There being uncertaainties aoboout the assumptions made in the present study,the analyses yield consistent results. If different cooling effects are considered, heat removal may be greatly enhanced. The LAVA experiements were performed at the Korea Atomic Energy Research Institute (KAERI) using al 2 O 3 /Fe thermite melt relocating down to the scaled vessel of a reactor lower head filled with preheated water. Test results indicated a cooling effect of water ingression through the debris-to-vessel gap and the intra-debris pores and crevices. If the cooling capacity of the intra-debris pores and crevices is comparable to debris-to-vessel heat removal capability, heat removal from the debris will be greatly augmented than heat removal by the gap cooling alone. The three nuclear reactor (KORI-2, YGN 3and4 and KNGR) calculation results for heat removal through the debris-to-vessel gap size of about 1mm were compared with the TMI-2 reactor calculation results for the case of gap cooling alone. (author)

  16. Fabrication of subcutaneous veins phantom for vessel visualization system

    Science.gov (United States)

    Cheng, Kai; Narita, Kazuyuki; Morita, Yusuke; Nakamachi, Eiji; Honda, Norihiro; Awazu, Kunio

    2013-09-01

    The technique of subcutaneous veins imaging by using NIR (Near Infrared Radiation) is widely used in medical applications, such as the intravenous injection and the blood sampling. In the previous study, an automatic 3D blood vessel search and automatic blood sampling system was newly developed. In order to validate this NIR imaging system, we adopted the subcutaneous vein in the human arm and its artificial phantom, which imitate the human fat and blood vessel. The human skin and subcutaneous vein is characterized as the uncertainty object, which has the individual specificity, non-accurate depth information, non-steady state and hardly to be fixed in the examination apparatus. On the other hand, the conventional phantom was quite distinct from the human's characteristics, such as the non-multilayer structure, disagreement of optical property. In this study, we develop a multilayer phantom, which is quite similar with human skin, for improvement of NIR detection system evaluation. The phantom consists of three layers, such as the epidermis layer, the dermis layer and the subcutaneous fat layer. In subcutaneous fat layer, we built a blood vessel. We use the intralipid to imitate the optical scattering characteristics of human skin, and the hemoglobin and melanin for the optical absorption characteristics. In this study, we did two subjects. First, we decide the fabrication process of the phantom. Second, we compared newly developed phantoms with human skin by using our NIR detecting system, and confirm the availability of these phantoms.

  17. MDCTA diagnosis of cerebral vessel disease among patients with arterial hypertension

    International Nuclear Information System (INIS)

    Romanko-Hrushchak, Nataliya

    2013-01-01

    to study changes involving cerebral vessels in patients with hypertension and various levels of total cardiovascular risk. One hundred and thirty-four patients underwent CT-angiography of intracranial vessels. Ninety-eight of them were diagnosed with hypertension. Taking into consideration high blood pressure, presence of risk factors and target organ damage subjects were divided into 4 groups: with low, medium, high and very high total cardiovascular risk. Control group included 36 patients. They were not diagnosed with hypertension at the time of examination. One hundred and five patients were examined using a 4-slice CT scanner (Toshiba Asteion 4, Toshiba Medical System, Japan), and 29 patients were examined using a 128-slice scanner (Siemens Definition AS+, Siemens Healthcare, Germany) with an injection system. We used iodine-containing contrast agents such as iodixanol and iopromide for angiography. Anatomical and topographic changes of cerebral vessels were most frequently found in hypertensive patients with high and very high total cardiovascular risk. Narrowing of vertebral vessels was the most common change (27 patients (27.55%), 21 patients (21.43%) had narrowing of the right artery, and 6 (6.12%) subjects – of the left one). Tortuous course of internal carotid arteries at the neck level was visualized in 11 patients (11.22%). Narrowing of A1 segment of anterior cerebral artery was noted in 9 patients (9.18%), of the right one – in 8 patients (8.16%), of the left one – in 1 patient (1.02%). Aneurysmal dilation of intracranial vessels was visualized in 6 patients (6.12%). Saccular aneurysm of left internal carotid artery was diagnosed in 2 patients (2.04%), one patient (1.02%) had right internal carotid artery aneurysm and one patient (1.02%) had an aneurysm of the basilar artery. the most common changes of cerebral vessels diagnosed in MDCTA among patients with hypertension included various degrees of narrowing of vertebral vessels, anterior

  18. Self-irradiation of the blood from selected nuclides in nuclear medicine

    International Nuclear Information System (INIS)

    Hänscheid, H; Fernández, M; Eberlein, U; Lassmann, M

    2014-01-01

    Nuclear medicine dosimetry and research in biodosimetry often require the knowledge of the absorbed dose to the blood. This study provides coefficients for the absorbed dose rates to the blood related to the activity concentration in the blood as a function of the vessel radius for radionuclides commonly used in targeted radiotherapy and in PET-diagnostics: C-11, F-18, Ga-68, Y-90, Tc-99 m, I-124, I-131, and Lu-177. The energy deposition patterns after nuclear disintegrations in blood vessel lumina (cylinders homogeneously filled with blood) with radii from 0.01 to 25.0 mm were simulated with the Monte-Carlo radiation transport code MCNPX. An additional contribution from photon radiation from activity in blood in the remainder of the body was taken into account based on a reasonable blood distribution model. The fraction of energy absorbed from non-penetrating radiation in the blood is low in thin blood vessels but approaches the total energy emitted by particles with increasing lumen radius. For photon radiation, irradiation to blood in small vessels is almost completely due to radioactive decays in distant blood distributed throughout the body, whereas the contribution from activity in the vessel becomes dominant for lumen radii exceeding 13 mm. The dependences of the absorbed dose rates on the lumen radius can be described with good accuracy by empirical functions which can be used to determine the absorbed doses to the blood and to the surrounding tissue. (paper)

  19. Synthetic analyses of the LAVA experimental results on in-vessel corium retention through gap cooling

    International Nuclear Information System (INIS)

    Kang, Kyoung Ho; Cho, Young Ro; Koo, Kil Mo; Park, Rae Joon; Kim, Jong Hwan; Kim, Jong Tae; Ha, Kwang Sun; Kim, Sang Baik; Kim, Hee Dong

    2001-03-01

    LAVA(Lower-plenum Arrested Vessel Attack) has been performed to gather proof of gap formation between the debris and lower head vessel and to evaluate the effect of the gap formation on in-vessel cooling. Through the total of 12 tests, the analyses on the melt relocation process, gap formation and the thermal and mechanical behaviors of the vessel were performed. The thermal behaviors of the lower head vessel were affected by the formation of the fragmented particles and melt pool during the melt relocation process depending on mass and composition of melt and subcooling and depth of water. During the melt relocation process 10.0 to 20.0 % of the melt mass was fragmented and also 15.5 to 47.5 % of the thermal energy of the melt was transferred to water. The experimental results address the non-adherence of the debris to the lower head vessel and the consequent gap formation between the debris and the lower head vessel in case there was an internal pressure load across the vessel abreast with the thermal load induced by the thermite melt. The thermal behaviors of the lower head vessel during the cooldown period were mainly affected by the heat removal characteristics through this gap, which were determined by the possibilities of the water ingression into the gap depending on the melt composition of the corium simulant. The enhanced cooling capacity through the gap was distinguished in the Al 2 O 3 melt tests. It could be inferred from the analyses on the heat removal capacity through the gap that the lower head vessel could effectively cooldown via heat removal in the gap governed by counter current flow limits(CCFL) even if 2mm thick gap should form in the 30 kg Al 2 O 3 melt tests, which was also confirmed through the variations of the conduction heat flux in the vessel and rapid cool down of the vessel outer surface in the Al 2 O 3 melt tests. In the case of large melt mass of 70 kg Al 2 O 3 melt, however, the infinite possibility of heat removal through the

  20. Removable samples for ITER—a feasibility and conceptual study

    International Nuclear Information System (INIS)

    Mertens, Ph; Neubauer, O; Philipps, V; Huber, A; Kirschner, A; Knaup, M; Borodin, D; Samm, U; Ciattaglia, S; Choi, C H; Gicquel, S; Hirai, T; Mitteau, R; Pitts, R A; Sadakov, S; Shimada, M; Veshchev, E

    2014-01-01

    The control of the radioactive inventory in the vacuum vessel of ITER is a main safety issue. Erosion of activated plasma-facing components (PFC) and co-deposition of tritiated dust on PFC and in areas below the divertor constitute the main sources of in-vessel radioactive inventory mobilizable in the case of an accident and also during venting of the vessel. To trace the dust and tritium inventory in the machine, the use of collectors in the form of removable samples was evaluated, beside other techniques, since it provides a reliable way to follow the history of the deposits and check critical areas. Four types of removable probes and two optional active diagnostics were selected out of about 30 different options. For all four probes, a conceptual design was worked out and the feasibility was checked with preliminary estimations of thermal and electromagnetic loads, as well as remote handling paths. The highest temperature estimated for the front face of all probes lies in the range 300–500 °C, which is tolerable. Installed in representative places, such removable samples may provide information about the dust and tritium distribution inside the vacuum vessel. (paper)

  1. Thermal Expansion of Vitrified Blood Vessels Permeated with DP6 and Synthetic Ice Modulators

    Science.gov (United States)

    Eisenberg, David P.; Taylor, Michael J.; Jimenez-Rios, Jorge L.; Rabin, Yoed

    2014-01-01

    This study provides thermal expansion data for blood vessels permeated with the cryoprotective cocktail DP6, when combined with selected synthetic ice modulators (SIMs): 12% polyethylene glycol 400, 6% 1,3-cyclohexanediol, and 6% 2,3-butanediol. The general classification of SIMs includes molecules that modulate ice nucleation and growth, or possess properties of stabilizing the amorphous state, by virtue of their chemical structure and at concentrations that are not explained on a purely colligative basis. The current study is part of an ongoing effort to characterize thermo-mechanical effects on structural integrity of cryopreserved materials, where thermal expansion is the driving mechanism to thermo-mechanical stress. This study focuses on the lower part of the cryogenic temperature range, where the cryoprotective agent (CPA) behaves as a solid for all practical applications. By combining results obtained in the current study with literature data on the thermal expansion in the upper part of the cryogenic temperature range, unified thermal expansion curves are presented. PMID:24769313

  2. Improved removal of blood contamination from ThinPrep cervical cytology samples for Raman spectroscopic analysis.

    Science.gov (United States)

    Traynor, Damien; Duraipandian, Shiyamala; Martin, Cara M; O'Leary, John J; Lyng, Fiona M

    2018-05-01

    There is an unmet need for methods to help in the early detection of cervical precancer. Optical spectroscopy-based techniques, such as Raman spectroscopy, have shown great potential for diagnosis of different cancers, including cervical cancer. However, relatively few studies have been carried out on liquid-based cytology (LBC) pap test specimens and confounding factors, such as blood contamination, have been identified. Previous work reported a method to remove blood contamination before Raman spectroscopy by pretreatment of the slides with hydrogen peroxide. The aim of the present study was to extend this work to excessively bloody samples to see if these could be rendered suitable for Raman spectroscopy. LBC ThinPrep specimens were treated by adding hydrogen peroxide directly to the vial before slide preparation. Good quality Raman spectra were recorded from negative and high grade (HG) cytology samples with no blood contamination and with heavy blood contamination. Good classification between negative and HG cytology could be achieved for samples with no blood contamination (sensitivity 92%, specificity 93%) and heavy blood contamination (sensitivity 89%, specificity 88%) with poorer classification when samples were combined (sensitivity 82%, specificity 87%). This study demonstrates for the first time the improved potential of Raman spectroscopy for analysis of ThinPrep specimens regardless of blood contamination. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  3. [Effect of Chinese drugs for activating blood circulation and removing blood stasis on carotid atherosclerosis and ischemic cerebrovascular events].

    Science.gov (United States)

    Lu, Yan; Li, Tao

    2014-03-01

    To explore the effect of Chinese drugs for activating blood circulation and removing blood stasis (CDABCRBS) on carotid atherosclerotic plaque and long-term ischemic cerebrovascular events. By using open and control method, effect of 4 groups of platelet antagonists, platelet antagonists + CDABCRBS, platelet antagonists +atorvastatin, platelet antagonists +atorvastatin +CDABCRBS on carotid atherosclerotic plaque and long-term ischemic cerebrovascular events of 90 cerebral infarction patients were analyzed. Through survival analysis, there was no statistical difference in the effect of the 4 interventions on the variation of carotid stenosis rates or ischemic cerebrovascular events (P > 0.05). The occurrence of ischemic cerebrovascular events could be postponed by about 4 months in those treated with platelet antagonists + CDABCRBS and platelet antagonists + atorvastatin +CDABCRBS. By multivariate Logistic analysis, age, hypertension, and clopidogrel were associated with stenosis of extracranial carotid arteries (P cerebrovascular accidents (P cerebrovascular events. CDABCRBS could effectively prolong the occurrence time of ischemic cerebrovascular events.

  4. High expression of insulin receptor on tumour-associated blood vessels in invasive bladder cancer predicts poor overall and progression-free survival.

    Science.gov (United States)

    Roudnicky, Filip; Dieterich, Lothar C; Poyet, Cedric; Buser, Lorenz; Wild, Peter; Tang, Dave; Camenzind, Peter; Ho, Chien Hsien; Otto, Vivianne I; Detmar, Michael

    2017-06-01

    Bladder cancer is a frequently recurring disease with a very poor prognosis once progressed to invasive stages, and tumour-associated blood vessels play a crucial role in this process. In order to identify novel biomarkers associated with progression, we isolated blood vascular endothelial cells (BECs) from human invasive bladder cancers and matched normal bladder tissue, and found that tumour-associated BECs greatly up-regulated the expression of insulin receptor (INSR). High expression of INSR on BECs of invasive bladder cancers was significantly associated with shorter progression-free and overall survival. Furthermore, increased expression of the INSR ligand IGF-2 in invasive bladder cancers was associated with reduced overall survival. INSR may therefore represent a novel biomarker to predict cancer progression. Mechanistically, we observed pronounced hypoxia in human bladder cancer tissue, and found a positive correlation between the expression of the hypoxia marker gene GLUT1 and vascular INSR expression, indicating that hypoxia drives INSR expression in tumour-associated blood vessels. In line with this, exposure of cultured BECs and human bladder cancer cell lines to hypoxia led to increased expression of INSR and IGF-2, respectively, and IGF-2 increased BEC migration through the activation of INSR in vitro. Taken together, we identified vascular INSR expression as a potential biomarker for progression in bladder cancer. Furthermore, our data suggest that IGF-2/INSR mediated paracrine crosstalk between bladder cancer cells and endothelial cells is functionally involved in tumour angiogenesis and may thus represent a new therapeutic target. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  5. A method for increasing the homogeneity of the temperature distribution during magnetic fluid hyperthermia with a Fe-Cr-Nb-B alloy in the presence of blood vessels

    Science.gov (United States)

    Tang, Yundong; Flesch, Rodolfo C. C.; Jin, Tao

    2017-06-01

    Magnetic hyperthermia ablates tumor cells by absorbing the thermal energy from magnetic nanoparticles (MNPs) under an external alternating magnetic field. The blood vessels (BVs) within tumor region can generally reduce treatment effectiveness due to the cooling effect of blood flow. This paper aims to investigate the cooling effect of BVs on the temperature field of malignant tumor regions using a complex geometric model and numerical simulation. For deriving the model, the Navier-Stokes equation for blood flow is combined with Pennes bio-heat transfer equation for human tissue. The effects on treatment temperature caused by two different BV distributions inside a mammary tumor are analyzed through numerical simulation under different conditions of flow rate considering a Fe-Cr-Nb-B alloy, which has low Curie temperature ranging from 42 °C to 45 °C. Numerical results show that the multi-vessel system has more obvious cooling effects than the single vessel one on the temperature field distribution for hyperthermia. Besides, simulation results show that the temperature field within tumor area can also be influenced by the velocity and diameter of BVs. To minimize the cooling effect, this article proposes a treatment method based on the increase of the thermal energy provided to MNPs associated with the adoption of low Curie temperature particles recently reported in literature. Results demonstrate that this approach noticeably improves the uniformity of the temperature field, and shortens the treatment time in a Fe-Cr-Nb-B system, thus reducing the side effects to the patient.

  6. Design of the ITER vacuum vessel

    International Nuclear Information System (INIS)

    Ioki, K.; Johnson, G.; Shimizu, K.; Williamson, D.

    1995-01-01

    The ITER vacuum vessel is a major safety barrier and must support electromagnetic loads during plasma disruptions and vertical displacement events (VDE) and withstand plausible accidents without losing confinement.The vacuum vessel has a double wall structure to provide structural and electrical continuity in the toroidal direction. The inner and outer shells and poloidal stiffening ribs between them are joined by welding, which gives the vessel the required mechanical strength. The space between the shells will be filled with steel balls and plate inserts to provide additional nuclear shielding. Water flowing in this space is required to remove nuclear heat deposition, which is 0.2-2.5% of the total fusion power. The minor and major radii of the tokamak are 3.9 m and 13 m respectively, and the overall height is 15 m. The total thickness of the vessel wall structure is 0.4-0.7 m.The inboard and outboard blanket segments are supported from the vacuum vessel. The support structure is required to withstand a large total vertical force of 200-300 MN due to VDE and to allow for differential thermal expansion.The first candidate for the vacuum vessel material is Inconel 625, due to its higher electric resistivity and higher yield strength, even at high temperatures. Type 316 stainless steel is also considered a vacuum vessel material candidate, owing to its large database and because it is supported by more conventional fabrication technology. (orig.)

  7. Recent experiences and problems in conducting pressure vessel surveillance examinations

    International Nuclear Information System (INIS)

    Perrin, J.S.

    1979-01-01

    Each of the commercial power reactors in the U.S.A. has a pressure vessel surveillance program. The purpose of the programs is to monitor the effects of radiation on the mechanical properties on the steel pressure vessels. A program for a given reactor includes a series of irradiation capsules containing neutron dosimeters and mechanical property specimens. The capsules are periodically removed during the life of the reactor and evaluated. The surveillance capsule examinations conducted to date have been valuable in assessing the effects of radiation on pressure vessels. However, a number of problems have been observed in the course of capsule examinations which potentially could reduce the maximum value of the data obtained. These problems are related to specimen design and preparation, capsule design and preparation, capsule installation and removal, capsule disassembly, specimen testing and evaluation, program documentation, and quality assurance. Examples of problems encountered in the preceding areas are presented in the present paper, and recommendations are made for minimization or prevention of these problems in future programs. Included in the recommendations is that appropriate ASTM standards, ASME Boiler and Pressure Vessel Code sections, and NRC regulations provide the appropriate framework for prevention of problems

  8. Confinement Vessel Assay System: Calibration and Certification Report

    Energy Technology Data Exchange (ETDEWEB)

    Frame, Katherine C. [Los Alamos National Laboratory; Bourne, Mark M. [Los Alamos National Laboratory; Crooks, William J. [Los Alamos National Laboratory; Evans, Louise [Los Alamos National Laboratory; Gomez, Cipriano [Retired CMR-OPS: OPERATIONS; Mayo, Douglas R. [Los Alamos National Laboratory; Miko, David K. [Los Alamos National Laboratory; Salazar, William R. [Los Alamos National Laboratory; Stange, Sy [Los Alamos National Laboratory; Vigil, Georgiana M. [Los Alamos National Laboratory

    2012-07-17

    Los Alamos National Laboratory has a number of spherical confinement vessels (CVs) remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1 to 2 inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the vessels. The Confinement Vessel Assay System (CVAS) was developed to measure the amount of SNM in CVs before and after cleanout. Prior to cleanout, the system will be used to perform a verification measurement of each vessel. After cleanout, the system will be used to perform safeguards-quality assays of {le} 100-g {sup 239}Pu equivalent in a vessel for safeguards termination. The system was calibrated in three different mass regions (low, medium, and high) to cover the entire plutonium mass range that will be assayed. The low mass calibration and medium mass calibration were verified for material positioned in the center of an empty vessel. The systematic uncertainty due to position bias was estimated using an MCNPX model to simulate the response of the system to material localized at various points along the inner surface of the vessel. The background component due to cosmic ray spallation was determined by performing measurements of an empty vessel and comparing to measurements in the same location with no vessel present. The CVAS has been tested and calibrated in preparation for verification and safeguards measurements of CVs before and after cleanout.

  9. Confinement Vessel Assay System: Calibration and Certification Report

    International Nuclear Information System (INIS)

    Frame, Katherine C.; Bourne, Mark M.; Crooks, William J.; Evans, Louise; Gomez, Cipriano; Mayo, Douglas R.; Miko, David K.; Salazar, William R.; Stange, Sy; Vigil, Georgiana M.

    2012-01-01

    Los Alamos National Laboratory has a number of spherical confinement vessels (CVs) remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1 to 2 inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the vessels. The Confinement Vessel Assay System (CVAS) was developed to measure the amount of SNM in CVs before and after cleanout. Prior to cleanout, the system will be used to perform a verification measurement of each vessel. After cleanout, the system will be used to perform safeguards-quality assays of (le) 100-g 239 Pu equivalent in a vessel for safeguards termination. The system was calibrated in three different mass regions (low, medium, and high) to cover the entire plutonium mass range that will be assayed. The low mass calibration and medium mass calibration were verified for material positioned in the center of an empty vessel. The systematic uncertainty due to position bias was estimated using an MCNPX model to simulate the response of the system to material localized at various points along the inner surface of the vessel. The background component due to cosmic ray spallation was determined by performing measurements of an empty vessel and comparing to measurements in the same location with no vessel present. The CVAS has been tested and calibrated in preparation for verification and safeguards measurements of CVs before and after cleanout.

  10. Small vessel vasculitis History, classification, etiology, histopathology, clinic, diagnosis and treatment

    International Nuclear Information System (INIS)

    Iglesias Gamarra, Antonio; Matteson, Eric L; Restrepo, Jose Felix

    2007-01-01

    Small-vessel vasculitis is a convenient descriptor for a wide range of diseases characterized by vascular inflammation of the venules, capillaries, and/or arterioles with pleomorphic clinical manifestations. The classical clinical phenotype is leucocytoclastic vasculitis with palpable purpura, but manifestations vary widely depending upon the organs involved. Histopathologic examination in leucocytoclastic vasculitis reveals angiocentric segmental inflammation, fibrinoid necrosis, and a neutrophilic infiltrate around the blood vessel walls with erythrocyte extravasation. The etiology of small-vessel vasculitis is unknown in many cases, but in others, drugs, post viral syndromes, malignancy, primary vasculitis such as microscopic polyarteritis, and connective tissue disorders are associated, The diagnosis of small- vessel vasculitis relies on a thorough history and physical examination, as well as relevant antibody testing including antinuclear antibody and anti neutrophil cytoplasmic antibody, hepatitis B and C serologies, assessment of complement, immunoglobulins, blood count, serum creatinine liver function tests, urinalysis, radiographic imaging and biopsy. The treatment is based primarily on corticosteroid and immunosuppressive agents

  11. Removal of focal atheromatous lesions by angioscopically guided high-speed rotary atherectomy. Preliminary experimental observations

    International Nuclear Information System (INIS)

    Ahn, S.S.; Auth, D.; Marcus, D.R.; Moore, W.S.

    1988-01-01

    A new high-speed rotary atherectomy device, inserted over a guide wire and directed with an angioscope, offers the potential of restoring patency of outflow vessels by boring out the atheromatous lesion of the orifices of runoff vessels. The device was tested on 68 cadaver arteries with atheromatous lesions involving the superficial femoral, popliteal, and tibial arteries. This was performed with either free segments or in situ with the device placed through a popliteal arteriotomy. The gross results of rotary atherectomy were assessed by angioscopy, angiography, or both. The luminal surfaces were studied with scanning electron microscopy and transverse sections of vessels were studied with light microscopy. The pulverized atheroma, in colloidal suspension, was analyzed for particle size by Coulter counter. The effect of a colloidal suspension of atheromatous particles on distal capillary circulation was measured in animal experiments. Obstructive lesions were successfully removed in 36 of 37 stenotic arteries (97%) and 18 of 31 completely occluded arteries (58%), an overall efficacy of 54 of 68 (79%). In successfully atherectomized arteries, angioscopy and angiography demonstrated a widely patent, smooth, polished surface. Light microscopy demonstrated removal of the diseased intima with maintenance of the outer media and adventitia. The pulverized atheroma particles were generally smaller than red blood cells and injection of the colloidal atheroma into canine femoral arteries failed to produce local tissue injury. We conclude that in the human cadaver this atherectomy device effectively enlarges and recanalizes obstructed superficial femoral, popliteal, and tibial arteries

  12. Passive safety systems for decay heat removal of MRX

    Energy Technology Data Exchange (ETDEWEB)

    Ochiai, M; Iida, H; Hoshi, T [Japan Atomic Energy Research Inst., Ibaraki (Japan). Nuclear Ship System Lab.

    1996-12-01

    The MRX (marine Reactor X) is an advanced marine reactor, its design has been studied in Japan Atomic Energy Research Institute. It is characterized by four features, integral type PWR, in-vessel type control rod drive mechanisms, water-filled containment vessel and passive decay heat removal system. A water-filled containment vessel is of great advantage since it ensures compactness of a reactor plant by realizing compact radiation shielding. The containment vessel also yields passive safety of MRX in the event of a LOCA by passively maintaining core flooding without any emergency water injection. Natural circulation of water in the vessels (reactor and containment vessels) is one of key factors of passive decay heat removal systems of MRX, since decay heat is transferred from fuel rods to atmosphere by natural circulation of the primary water, water in the containment vessel and thermal medium in heat pipe system for the containment vessel water cooling in case of long terms cooling after a LOCA as well as after reactor scram. Thus, the ideal of water-filled containment vessel is considered to be very profitable and significant in safety and economical point of view. This idea is, however, not so familiar for a conventional nuclear system, so experimental and analytical efforts are carried out for evaluation of hydrothermal behaviours in the reactor pressure vessel and in the containment vessel in the event of a LOCA. The results show the effectiveness of the new design concept. Additional work will also be conducted to investigate the practical maintenance of instruments in the containment vessel. (author). 4 refs, 9 figs, 2 tabs.

  13. Initial conditioning of the TFTR vacuum vessel

    International Nuclear Information System (INIS)

    Dylla, H.F.; Blanchard, W.R.; Krawchuk, R.B.; Hawryluk, R.J.; Owens, D.K.

    1984-01-01

    We report on the initial conditioning of the Tokamak Fusion Test Reactor (TFTR) vacuum vessel prior to the initiation of first plasma discharges, and during subsequent operation with high power ohmically-heated plasmas. Following evacuation of the 86 m 3 vessel with the 10 4 1/s high vacuum pumping system, the vessel was conditioned by a 15 A dc glow discharge in H 2 at a pressure of 5 mTorr. Rapid-pulse discharge cleaning was used subsequently to preferentially condition the graphite plasma limiters. The effectiveness of the discharge cleaning was monitored by measuring the exhaust rates of the primary discharge products (CO/C 2 H 4 , CH 4 , and H 2 O). After 175 hours of glow discharge treatment, the equivalent of 50 monolayers of C and O was removed from the vessel, and the partial pressures of impurity gases were reduced to the range of 10 -9 -10 -10 Torr

  14. Combination probe for optically assisted ultrasonic velocity-change imaging aimed at detecting unstable blood vessel plaque

    Science.gov (United States)

    Tanigawa, Shohei; Mano, Kazune; Wada, Kenji; Matsunaka, Toshiyuki; Horinaka, Hiromichi

    2016-04-01

    Blood vessel plaque with a large lipid core is at risk of becoming thrombus and is likely to induce acute heart disease. To prevent this, it is necessary to determine not only the plaque's size but also its chemical composition. We, therefore, made the prototype of a combination probe to diagnose carotid artery plaque. It is used to differentiate propagation characteristics between light spectra and ultrasonic images. By propagating light and ultrasound along a common direction, it is possible to effectively warm the diagnosis domain. Moreover, the probe is thought to be compact and be easy to use for diagnosing human carotid artery plaque. We applied the combination probe to a carotid artery phantom with a lipid area and obtained an image of the ultrasonic velocity change in the fatty area.

  15. A computational model predicting disruption of blood vessel development.

    Directory of Open Access Journals (Sweden)

    Nicole Kleinstreuer

    2013-04-01

    Full Text Available Vascular development is a complex process regulated by dynamic biological networks that vary in topology and state across different tissues and developmental stages. Signals regulating de novo blood vessel formation (vasculogenesis and remodeling (angiogenesis come from a variety of biological pathways linked to endothelial cell (EC behavior, extracellular matrix (ECM remodeling and the local generation of chemokines and growth factors. Simulating these interactions at a systems level requires sufficient biological detail about the relevant molecular pathways and associated cellular behaviors, and tractable computational models that offset mathematical and biological complexity. Here, we describe a novel multicellular agent-based model of vasculogenesis using the CompuCell3D (http://www.compucell3d.org/ modeling environment supplemented with semi-automatic knowledgebase creation. The model incorporates vascular endothelial growth factor signals, pro- and anti-angiogenic inflammatory chemokine signals, and the plasminogen activating system of enzymes and proteases linked to ECM interactions, to simulate nascent EC organization, growth and remodeling. The model was shown to recapitulate stereotypical capillary plexus formation and structural emergence of non-coded cellular behaviors, such as a heterologous bridging phenomenon linking endothelial tip cells together during formation of polygonal endothelial cords. Molecular targets in the computational model were mapped to signatures of vascular disruption derived from in vitro chemical profiling using the EPA's ToxCast high-throughput screening (HTS dataset. Simulating the HTS data with the cell-agent based model of vascular development predicted adverse effects of a reference anti-angiogenic thalidomide analog, 5HPP-33, on in vitro angiogenesis with respect to both concentration-response and morphological consequences. These findings support the utility of cell agent-based models for simulating a

  16. Synthesis and characterization of Gadolinium-Lectin conjugates as selective blood-vessel contrast agents for magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Pashkunova-Martic, I.

    2004-11-01

    Molecular imaging without use of ionizing radiation has recently been developed for both magnetic resonance and ultrasound imaging (MRI, US) and is expected to play a major future role in diagnosis and monitoring of tumours. In MRI, targeted nanoparticle contrast media (CM) with high relaxivities are required in order to obtain adequate signal-to-noise ratios, due to the low number of target sites. The size, charge and chemical constitution of the targeted nanoparticle CM are expected to influence nanoparticle interactions with cells and tissue elements significantly, and hence the targeting, the accumulation and dwell time at the targeted site, and the type and rate of clearance of the nanoparticles. The work reported here aims to characterise and optimise these parameters in mouse and human models, using nanoparticles targeted to a major carbohydrate determinant of the endothelial cell surface which is present in all blood vessels. Specific binding to the endothelium was demonstrated in both living and chemically fixed human vessels and in mice. Long-standing spin-echo and FLASH-3D images were obtained in the vasculature of living mice, in strong contrast to the rapid renal clearance of gadolinium-DTPA chelates which are widely used in the clinic. Nanoparticle size was found to be a major determinant of the biological response, and our data indicate that an optimal nanoparticle size lies between 50-100 nm diameter. We expect that hyperpermeable vessels present in tumours will permit targeting of optimised nanoparticles to the tumour cells, permitting MRI monitoring of the tumour. (author)

  17. Personal identification based on blood vessels of retinal fundus images

    Science.gov (United States)

    Fukuta, Keisuke; Nakagawa, Toshiaki; Hayashi, Yoshinori; Hatanaka, Yuji; Hara, Takeshi; Fujita, Hiroshi

    2008-03-01

    Biometric technique has been implemented instead of conventional identification methods such as password in computer, automatic teller machine (ATM), and entrance and exit management system. We propose a personal identification (PI) system using color retinal fundus images which are unique to each individual. The proposed procedure for identification is based on comparison of an input fundus image with reference fundus images in the database. In the first step, registration between the input image and the reference image is performed. The step includes translational and rotational movement. The PI is based on the measure of similarity between blood vessel images generated from the input and reference images. The similarity measure is defined as the cross-correlation coefficient calculated from the pixel values. When the similarity is greater than a predetermined threshold, the input image is identified. This means both the input and the reference images are associated to the same person. Four hundred sixty-two fundus images including forty-one same-person's image pairs were used for the estimation of the proposed technique. The false rejection rate and the false acceptance rate were 9.9×10 -5% and 4.3×10 -5%, respectively. The results indicate that the proposed method has a higher performance than other biometrics except for DNA. To be used for practical application in the public, the device which can take retinal fundus images easily is needed. The proposed method is applied to not only the PI but also the system which warns about misfiling of fundus images in medical facilities.

  18. High blood pressure and eye disease

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000999.htm High blood pressure and eye disease To use the sharing features on this page, please enable JavaScript. High blood pressure can damage blood vessels in the retina . The ...

  19. Lattice Boltzmann simulation of behaviour of particles moving in blood vessels under the rolling massage

    International Nuclear Information System (INIS)

    Hou-Hui, Yi; Cai-Feng, Wang; Xiao-Feng, Yang; Hua-Bing, Li

    2009-01-01

    The rolling massage is one of the most important manipulations in Chinese massage, which is expected to eliminate many diseases. Here, the effect of the rolling massage on a pair of particles moving in blood vessels under rolling massage manipulation is studied by the lattice Boltzmann simulation. The simulated results show that the motion of each particle is considerably modified by the rolling massage, and it depends on the relative rolling velocity, the rolling depth, and the distance between particle position and rolling position. Both particles' translational average velocities increase almost linearly as the rolling velocity increases, and obey the same law. The increment of the average relative angular velocity for the leading particle is smaller than that of the trailing one. The result is helpful for understanding the mechanism of the massage and to further develop the rolling techniques. (classical areas of phenomenology)

  20. Influencing factors affecting the retinal blood vessel morphology in patients with diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Xiao-Lu Kong

    2017-03-01

    Full Text Available AIM: To analyze the influencing factors affecting retinal blood vessel morphology in patients with diabetes mellitus. METHODS: Totally 312 patients with type 2 diabetes mellitus in our hospital from January 2012 to September 2016 were selected as study subjects. The patients were examined by fundus photography and related laboratory. As grouping factors in the patients'age, sex, disease duration, smoking, drinking, hypertension, hyperlipidemia or diabetic nephropathy, we compared the incidence of retinal vascular changes in different groups. The meaningful factors were introduced into the Logistic regression equation again. Independent risk factors for retinal vascular changes in patients with diabetes mellitus were screened out. RESULTS:In 312 cases of patients with type 2 diabetes mellitus,169 cases were accompanied with retinal vascular abnormalities, and 143 cases were not associated with retinal vascular abnormalities. Univariate analysis showed that age, duration of disease, hypertension, hyperlipidemia or diabetes nephropathy were significantly correlated with retinal vascular morphological changes(PP>0.05. Retinal vascular abnormalities were used as the dependent variable, and the above mentioned factors were grouped as independent variables. By Logistic stepwise regression analysis showed that the course of disease, patients with hypertension or diabetic nephropathy were the independent risk factors of abnormal retinal vascular morphology(PCONCLUSION: The independent risk factors for the occurrence of retinal vascular changes in patients with diabetes mellitus are increased course of disease, hypertension or diabetic nephropathy. Early diagnosis and intervention, to take measures and control blood pressure, reduce kidney damage can reduce the incidence of diabetic retinopathy, and macrovascular disease caused by diabetes, the incidence of adverse cardiovascular and cerebrovascular events.

  1. Multi-level deep supervised networks for retinal vessel segmentation.

    Science.gov (United States)

    Mo, Juan; Zhang, Lei

    2017-12-01

    Changes in the appearance of retinal blood vessels are an important indicator for various ophthalmologic and cardiovascular diseases, including diabetes, hypertension, arteriosclerosis, and choroidal neovascularization. Vessel segmentation from retinal images is very challenging because of low blood vessel contrast, intricate vessel topology, and the presence of pathologies such as microaneurysms and hemorrhages. To overcome these challenges, we propose a neural network-based method for vessel segmentation. A deep supervised fully convolutional network is developed by leveraging multi-level hierarchical features of the deep networks. To improve the discriminative capability of features in lower layers of the deep network and guide the gradient back propagation to overcome gradient vanishing, deep supervision with auxiliary classifiers is incorporated in some intermediate layers of the network. Moreover, the transferred knowledge learned from other domains is used to alleviate the issue of insufficient medical training data. The proposed approach does not rely on hand-crafted features and needs no problem-specific preprocessing or postprocessing, which reduces the impact of subjective factors. We evaluate the proposed method on three publicly available databases, the DRIVE, STARE, and CHASE_DB1 databases. Extensive experiments demonstrate that our approach achieves better or comparable performance to state-of-the-art methods with a much faster processing speed, making it suitable for real-world clinical applications. The results of cross-training experiments demonstrate its robustness with respect to the training set. The proposed approach segments retinal vessels accurately with a much faster processing speed and can be easily applied to other biomedical segmentation tasks.

  2. MR vascular fingerprinting: A new approach to compute cerebral blood volume, mean vessel radius, and oxygenation maps in the human brain.

    Science.gov (United States)

    Christen, T; Pannetier, N A; Ni, W W; Qiu, D; Moseley, M E; Schuff, N; Zaharchuk, G

    2014-04-01

    In the present study, we describe a fingerprinting approach to analyze the time evolution of the MR signal and retrieve quantitative information about the microvascular network. We used a Gradient Echo Sampling of the Free Induction Decay and Spin Echo (GESFIDE) sequence and defined a fingerprint as the ratio of signals acquired pre- and post-injection of an iron-based contrast agent. We then simulated the same experiment with an advanced numerical tool that takes a virtual voxel containing blood vessels as input, then computes microscopic magnetic fields and water diffusion effects, and eventually derives the expected MR signal evolution. The parameter inputs of the simulations (cerebral blood volume [CBV], mean vessel radius [R], and blood oxygen saturation [SO2]) were varied to obtain a dictionary of all possible signal evolutions. The best fit between the observed fingerprint and the dictionary was then determined by using least square minimization. This approach was evaluated in 5 normal subjects and the results were compared to those obtained by using more conventional MR methods, steady-state contrast imaging for CBV and R and a global measure of oxygenation obtained from the superior sagittal sinus for SO2. The fingerprinting method enabled the creation of high-resolution parametric maps of the microvascular network showing expected contrast and fine details. Numerical values in gray matter (CBV=3.1±0.7%, R=12.6±2.4μm, SO2=59.5±4.7%) are consistent with literature reports and correlated with conventional MR approaches. SO2 values in white matter (53.0±4.0%) were slightly lower than expected. Numerous improvements can easily be made and the method should be useful to study brain pathologies. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Expression of the growth factor progranulin in endothelial cells influences growth and development of blood vessels: a novel mouse model.

    Science.gov (United States)

    Toh, Huishi; Cao, Mingju; Daniels, Eugene; Bateman, Andrew

    2013-01-01

    Progranulin is a secreted glycoprotein that regulates cell proliferation, migration and survival. It has roles in development, tumorigenesis, wound healing, neurodegeneration and inflammation. Endothelia in tumors, wounds and placenta express elevated levels of progranulin. In culture, progranulin activates endothelial proliferation and migration. This suggested that progranulin might regulate angiogenesis. It was, however, unclear how elevated endothelial progranulin levels influence vascular growth in vivo. To address this issue, we generated mice with progranulin expression targeted specifically to developing endothelial cells using a Tie2-promoter/enhancer construct. Three Tie2-Grn mouse lines were generated with varying Tie2-Grn copy number, and were called GrnLo, GrnMid, and GrnHi. All three lines showed increased mortality that correlates with Tie2-Grn copy number, with greatest mortality and lowest germline transmission in the GrnHi line. Death of the transgenic animals occurred around birth, and continued for three days after birth. Those that survived beyond day 3 survived into adulthood. Transgenic neonates that died showed vascular abnormalities of varying severity. Some exhibited bleeding into body cavities such as the pericardial space. Smaller localized hemorrhages were seen in many organs. Blood vessels were often dilated and thin-walled. To establish the development of these abnormalities, we examined mice at early (E10.5-14.5) and later (E15.5-17.5) developmental phases. Early events during vasculogenesis appear unaffected by Tie2-Grn as apparently normal primary vasculature had been established at E10.5. The earliest onset of vascular abnormality was at E15.5, with focal cerebral hemorrhage and enlarged vessels in various organs. Aberrant Tie2-Grn positive vessels showed thinning of the basement membrane and reduced investiture with mural cells. We conclude that progranulin promotes exaggerated vessel growth in vivo, with subsequent effects in

  4. Expression of the growth factor progranulin in endothelial cells influences growth and development of blood vessels: a novel mouse model.

    Directory of Open Access Journals (Sweden)

    Huishi Toh

    Full Text Available Progranulin is a secreted glycoprotein that regulates cell proliferation, migration and survival. It has roles in development, tumorigenesis, wound healing, neurodegeneration and inflammation. Endothelia in tumors, wounds and placenta express elevated levels of progranulin. In culture, progranulin activates endothelial proliferation and migration. This suggested that progranulin might regulate angiogenesis. It was, however, unclear how elevated endothelial progranulin levels influence vascular growth in vivo. To address this issue, we generated mice with progranulin expression targeted specifically to developing endothelial cells using a Tie2-promoter/enhancer construct. Three Tie2-Grn mouse lines were generated with varying Tie2-Grn copy number, and were called GrnLo, GrnMid, and GrnHi. All three lines showed increased mortality that correlates with Tie2-Grn copy number, with greatest mortality and lowest germline transmission in the GrnHi line. Death of the transgenic animals occurred around birth, and continued for three days after birth. Those that survived beyond day 3 survived into adulthood. Transgenic neonates that died showed vascular abnormalities of varying severity. Some exhibited bleeding into body cavities such as the pericardial space. Smaller localized hemorrhages were seen in many organs. Blood vessels were often dilated and thin-walled. To establish the development of these abnormalities, we examined mice at early (E10.5-14.5 and later (E15.5-17.5 developmental phases. Early events during vasculogenesis appear unaffected by Tie2-Grn as apparently normal primary vasculature had been established at E10.5. The earliest onset of vascular abnormality was at E15.5, with focal cerebral hemorrhage and enlarged vessels in various organs. Aberrant Tie2-Grn positive vessels showed thinning of the basement membrane and reduced investiture with mural cells. We conclude that progranulin promotes exaggerated vessel growth in vivo, with

  5. Cerebral amyloid angiopathy, blood-brain barrier disruption and amyloid accumulation in SAMP8 mice.

    Science.gov (United States)

    del Valle, Jaume; Duran-Vilaregut, Joaquim; Manich, Gemma; Pallàs, Mercè; Camins, Antoni; Vilaplana, Jordi; Pelegrí, Carme

    2011-01-01

    Cerebrovascular dysfunction and β-amyloid peptide deposition on the walls of cerebral blood vessels might be an early event in the development of Alzheimer's disease. Here we studied the time course of amyloid deposition in blood vessels and blood-brain barrier (BBB) disruption in the CA1 subzone of the hippocampus of SAMP8 mice and the association between these two variables. We also studied the association between the amyloid deposition in blood vessels and the recently described amyloid clusters in the parenchyma, as well as the association of these clusters with vessels in which the BBB is disrupted. SAMP8 mice showed greater amyloid deposition in blood vessels than age-matched ICR-CD1 control mice. Moreover, at 12 months of age the number of vessels with a disrupted BBB had increased in both strains, especially SAMP8 animals. At this age, all the vessels with amyloid deposition showed BBB disruption, but several capillaries with an altered BBB showed no amyloid on their walls. Moreover, amyloid clusters showed no spatial association with vessels with amyloid deposition, nor with vessels in which the BBB had been disrupted. Finally, we can conclude that vascular amyloid deposition seems to induce BBB alterations, but BBB disruption may also be due to other factors. Copyright © 2011 S. Karger AG, Basel.

  6. A low-hemolysis blood aspirator conserves blood during surgery.

    Science.gov (United States)

    Clague, C T; Blackshear, P L

    1995-01-01

    Blood damage caused by traditional vacuum-operated suction tubes, particularly when air is aspirated along with the blood, usually exceeds damage from all other components. In addition to platelet injury, there is a high degree of hemolysis, which leads to high plasma hemoglobin levels and reduces the number of red blood cells available for reinfusion during cases of blood conservation, such as autologous transfusion and cardiac bypass. This work was undertaken to minimize hemolysis, and the accompanying platelet destruction, during aspiration, with the design of a jet-driven aspirator that separates and removes air from blood immediately within the suction tip. The jet-driven aspirator can suction blood at a range of rates from 100 to at least 700 ml/min, separates and removes 80-100% of aspirated air, operates at any orientation, and generates subatmospheric pressures on the order of only 1 inch H2O. In-vitro hemolysis testing showed a significant reduction in average plasma hemoglobin release, from 19.4 mg/dl to 1.8 mg/dl, when air was removed during blood aspiration. In comparative testing with a conventional vacuum suction tube, the jet-driven aspirator showed significantly less hemolysis than the conventional aspirator at comparable rates of air and blood aspiration.

  7. A basic study on the ITER tritium storage vessel design and components

    International Nuclear Information System (INIS)

    Chung, H. S.; Ahn, D. H.; Kim, K. R.; Yim, S. P.; Paek, S. W.; Lee, M. S.; Lee, S. H.; Shim, M. H.

    2006-01-01

    The ZrCo getter beds are built of a primary vessel which contains the ZrCo powder mixed with Cu spheres of less than one mm diameter and of a secondary outer vessel. The purpose of the secondary outer vessel is to capture permeated or leaked tritium and to present a good thermal insulation when properly evacuated. A third volume, a helium filled loop, is installed in the primary volume to remove the decay heat and is used to perform tritium accountancy measurements

  8. Placental gene-expression profiles of intrahepatic cholestasis of pregnancy reveal involvement of multiple molecular pathways in blood vessel formation and inflammation.

    Science.gov (United States)

    Du, QiaoLing; Pan, YouDong; Zhang, YouHua; Zhang, HaiLong; Zheng, YaJuan; Lu, Ling; Wang, JunLei; Duan, Tao; Chen, JianFeng

    2014-07-07

    Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-associated liver disease with potentially deleterious consequences for the fetus, particularly when maternal serum bile-acid concentration >40 μM. However, the etiology and pathogenesis of ICP remain elusive. To reveal the underlying molecular mechanisms for the association of maternal serum bile-acid level and fetal outcome in ICP patients, DNA microarray was applied to characterize the whole-genome expression profiles of placentas from healthy women and women diagnosed with ICP. Thirty pregnant women recruited in this study were categorized evenly into three groups: healthy group; mild ICP, with serum bile-acid concentration ranging from 10-40 μM; and severe ICP, with bile-acid concentration >40 μM. Gene Ontology analysis in combination with construction of gene-interaction and gene co-expression networks were applied to identify the core regulatory genes associated with ICP pathogenesis, which were further validated by quantitative real-time PCR and histological staining. The core regulatory genes were mainly involved in immune response, VEGF signaling pathway and G-protein-coupled receptor signaling, implying essential roles of immune response, vasculogenesis and angiogenesis in ICP pathogenesis. This implication was supported by the observed aggregated immune-cell infiltration and deficient blood vessel formation in ICP placentas. Our study provides a system-level insight into the placental gene-expression profiles of women with mild or severe ICP, and reveals multiple molecular pathways in immune response and blood vessel formation that might contribute to ICP pathogenesis.

  9. Long-term streptozotocin-induced diabetes in rats leads to severe damage of brain blood vessels and neurons via enhanced oxidative stress.

    Science.gov (United States)

    Yang, Hongying; Fan, Shourui; Song, Dianping; Wang, Zhuo; Ma, Shungao; Li, Shuqing; Li, Xiaohong; Xu, Mian; Xu, Min; Wang, Xianmo

    2013-02-01

    The aim of this study was to investigate pathophysiological alterations and oxidative stress in various stages of streptozotocin (STZ)‑induced diabetes mellitus (DM) in rats. Male Sprague-Dawley rats (120) were randomized into DM and control groups. Body mass, plasma glucose, glycated hemoglobin (HbA1c), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) levels, as well as aldose reductase (AR) activities, in brain tissue and serum were determined. Electron microscopy was used to observe neuron and vessel changes in the brain. In STZ‑treated rats, blood glucose, low density lipoproteins, triglycerides and total cholesterol levels increased 1.43‑3.0‑fold and high density lipoprotein, HbA1c and insulin sensitivity index increased 1.1‑1.23‑fold compared with control. At week 16 following treatment, DM rat serum H2O2 concentration was increased, indicating oxidative stress and mRNA levels of GPx and SOD were 2‑fold higher than the control. Protein GPx and SOD levels were reduced (PNeuron cells and blood vessels in the DM rat brains became increasingly abnormal over time with altered Golgi bodies, mitochondria and endoplasmic reticulum cisterns, concurrent with SOD inactivation and AR protein accumulation. Disease progression in rats with STZ‑induced DM included brain pathologies with vascular and neuron cell abnormalities, associated with the reduction of SOD, CAT and GPx activities and also AR accumulation.

  10. Non-gated vessel wall imaging of the internal carotid artery using radial scanning and fast spin echo sequence. Evaluation of vessel signal intensity by flow rate at 3.0 tesla

    International Nuclear Information System (INIS)

    Nakamura, Manami; Makabe, Takeshi; Ichikawa, Masaki; Hatakeyama, Ryohei; Sugimori, Hiroyuki; Sakata, Motomichi

    2013-01-01

    Vessel wall imaging using radial scanning does not use a blood flow suppression pulse with gated acquisition. It has been proposed that there may not be a flow void effect if the flow rate is slow; however, this has yet to be empirically tested. To clarify the relationship between the signal intensity of the vessel lumen and the blood flow rate in a flow phantom, we investigated the usefulness of vessel wall imaging at 3.0 tesla (T). We measured the signal intensity while changing the flow rate in the flow phantom. Radial scanning at 1.5 T showed sufficient flow voids at above medium flow rates. There was no significant difference in lumen signal intensity at the carotid artery flow rate. The signal intensity of the vessel lumen decreased sufficiently using the radial scan method at 3.0 T. We thus obtained sufficient flow void effects at the carotid artery flow rate. We conclude this technique to be useful for evaluating plaque if high contrast can be maintained for fixed tissue (such as plaque) and the vessel lumen. (author)

  11. Experimental study on in-vessel debris coolability during severe accident

    International Nuclear Information System (INIS)

    Kim, S. B.; Park, R. J.; Kim, H. D.

    2002-05-01

    A research program, called SONATA-IV(Simulation of Naturally Arrested Thermal Attack In-Vessel), has been performed to verify the gap cooling mechanism of corium in the lower plenum, and to develop management and mitigation strategies under severe accident conditions. For the proof-of-principles experiment, the LAVA(Lower-plenum Arrested Vessel Attack) experiments have been performed to gather proof of gap formation and to evaluate the gap effect on in-vessel cooling, using Al 2 O 3 /Fe (or Al 2 O 3 only) thermite melt as corium simulant. And also the CHFG(Critical Heat Flux in Gap) experiments have been performed to measure the critical power and to investigate the inherent cooling mechanism in the hemispherical narrow gap. In addition to the experiments, LILAC code was developed to analyze and predict the thermo-hydraulic phenomena of the corium relocated in the reactor lower plenum. It could be found from the LAVA and CHFG experimental results that continuous gap ranged from 1 to 5 mm was formed and that maximum heat removal capacity through a gap is a key factor in determining the potentials of the integrity of the vessel. After all the possibility of IVR(In-Vessel corium Retention) through gap cooling highly depends on the melt relocated into the lower plenum and the gap size. So, feasibility experiments have been performed for the assessment of improved IVR concepts using an internal engineered gap device and a dual strategy of In/Ex-vessel cooling using the LAVA facility. It is preliminarily concluded that these cooling measures lead to an enhanced cooling of the corium in the lower plenum of the reactor vessel. The additional studies will be performed to verify the quantitative heat removal capacity for these cooling measures in the 2nd phase of mid- and long term project period

  12. Combining endoscopes with PIV and digital holography for the study of vessel model mechanics

    International Nuclear Information System (INIS)

    Arévalo, Laura; Palero, Virginia; Andrés, Nieves; Arroyo, M P; Lobera, Julia

    2015-01-01

    In this work traditional fluid and solid mechanics measurement techniques have been combined with endoscopes for the study of blood vessel models’ mechanical properties. Endoscopes have been used as the imaging part of a high-speed PIV system to obtain the velocity field in a vessel model immersed in a container with a refractive index-matching liquid. In this way, we take advantage of the fact that the endoscope tip can be immersed in liquid. Endoscopes have also been used as the imaging and illuminating part of a digital holographic set-up for wall deformation measurement. The novelty of this work is that only one endoscope was used for illuminating and observing the vessel model, using the endoscope’s own illuminating system as the illumination source. The performance of endoscopes in different vessel models has been tested. The results of flow velocity and wall deformation in the different blood vessel models are presented. (paper)

  13. Correlations Between the Density of Tryptase Positive Mast Cells (DMCT and that of New Blood Vessels (CD105+ in Patients with Gastric Cancer

    Directory of Open Access Journals (Sweden)

    Micu Gianina Viorica

    2016-06-01

    Full Text Available Mast cells proteases, tryptase and chymase are directly involved in the growth and progression of solid tumors due to their important role in tumor angiogenesis. We examined the density of tryptase positive mast cells and the mean density of new blood vessels in gastric malignant tumors of patients with and without Helicobacter pylori infection, using immunohistochemical staining for tryptase (for mast cells and CD 105 (for new vessels. Tryptase and CD 105 expression was detected in gastrectomy specimens. In this study, mast cell density correlates with angiogenesis and the growth and progression of gastric cancer. It also shows that the participation of Helicobacter pylori infection in the growth and progress of gastric neoplasia is due to an increase of peritumoral angiogenesis, with subsequent local and distant tumor spread and perivascular growth, but without perineural and nodal involvement.

  14. Mechanism of /sup 67/Ga uptake by an experimental abscess. Permeability of plasma from blood vessel in abscess

    Energy Technology Data Exchange (ETDEWEB)

    Nitta, Kazuo; Ogawa, Hiroshi; Ando, Atsushi; Ando, Itsuko; Hiraki, Tatsunosuke; Hisada, Kinichi

    1985-06-01

    In the previous paper, we reported that /sup 67/Ga was accumulated in abscess and uptake rate of /sup 67/Ga in abscess increased with time after the injection of /sup 67/Ga-citrate. The present study was undertaken to elucidate the influence of blood flow on the accumulation of /sup 67/Ga in abscess. Five days after subcutaneous injection of 0.2 ml of turpentine to the rats, /sup 131/I-human serum albumin (HSA) was injected intravenously to the rats. At an appropriate time after the injection (10 min to 6 days), uptake rates of /sup 131/I-HSA in abscess and normal tissues were measured. Similarly, /sup 51/Cr-red blood cells (RBC) were injected intravenously to the above rats and the uptake rates of /sup 51/Cr-RBC were also measured. One, three, and 24 hours after injection of /sup 131/I-HSA, the uptake rates of /sup 131/I-HSA in abscess were 1.32 %dose/g, 1.84 %dose/g, and 0.82 %dose/g, respectively. However, the uptake rates of /sup 51/Cr-RBC in abscess was very small, and the value was 0.14 %dose/g at 24 hours after the injection. In the case of abscess, blood in the tissue fluid was very little, but the permeability of /sup 131/I-HSA from the blood vessel in the tissue was much larger than that of normal tissues. From these facts, it was deduced that the accelerated permeability caused the abscess accumulation of /sup 67/Ga.

  15. Reducing the data: Analysis of the role of vascular geometry on blood flow patterns in curved vessels

    Science.gov (United States)

    Alastruey, Jordi; Siggers, Jennifer H.; Peiffer, Véronique; Doorly, Denis J.; Sherwin, Spencer J.

    2012-03-01

    Three-dimensional simulations of blood flow usually produce such large quantities of data that they are unlikely to be of clinical use unless methods are available to simplify our understanding of the flow dynamics. We present a new method to investigate the mechanisms by which vascular curvature and torsion affect blood flow, and we apply it to the steady-state flow in single bends, helices, double bends, and a rabbit thoracic aorta based on image data. By calculating forces and accelerations in an orthogonal coordinate system following the centreline of each vessel, we obtain the inertial forces (centrifugal, Coriolis, and torsional) explicitly, which directly depend on vascular curvature and torsion. We then analyse the individual roles of the inertial, pressure gradient, and viscous forces on the patterns of primary and secondary velocities, vortical structures, and wall stresses in each cross section. We also consider cross-sectional averages of the in-plane components of these forces, which can be thought of as reducing the dynamics of secondary flows onto the vessel centreline. At Reynolds numbers between 50 and 500, secondary motions in the directions of the local normals and binormals behave as two underdamped oscillators. These oscillate around the fully developed state and are coupled by torsional forces that break the symmetry of the flow. Secondary flows are driven by the centrifugal and torsional forces, and these are counterbalanced by the in-plane pressure gradients generated by the wall reaction. The viscous force primarily opposes the pressure gradient, rather than the inertial forces. In the axial direction, and depending on the secondary motion, the curvature-dependent Coriolis force can either enhance or oppose the bulk of the axial flow, and this shapes the velocity profile. For bends with little or no torsion, the Coriolis force tends to restore flow axisymmetry. The maximum circumferential and axial wall shear stresses along the centreline

  16. Perfusion by Arterial Spin labelling following Single dose Tadalafil In Small vessel disease (PASTIS)

    DEFF Research Database (Denmark)

    Pauls, Mathilde M H; Clarke, Natasha; Trippier, Sarah

    2017-01-01

    vascular territories. The aim of this trial is to test the hypothesis that tadalafil increases cerebral blood flow in older people with small vessel disease. METHODS/DESIGN: Perfusion by Arterial Spin labelling following Single dose Tadalafil In Small vessel disease (PASTIS) is a phase II randomised double......-blind crossover trial. In two visits, 7-30 days apart, participants undergo arterial spin labelling to measure cerebral blood flow and a battery of cognitive tests, pre- and post-dosing with oral tadalafil (20 mg) or placebo. SAMPLE SIZE: 54 participants are required to detect a 15% increase in cerebral blood...

  17. Vasoactive receptors in abdominal blood vessels of the dogfish shark, Squalus acanthias.

    Science.gov (United States)

    Evans, D H

    2001-01-01

    Previous studies have demonstrated that the ventral aorta of the dogfish shark, Squalus acanthias, responds to a variety of cell-signaling agents. To investigate the generality of vasoactive receptors in the shark vasculature, in particular a conductance artery (anterior mesenteric) and vein (posterior intestinal), I measured the effect of acetylcholine, endothelin, nitric oxide, natriuretic peptides, and prostaglandins on tension in isolated rings from these vessels. Both vessels responded to these agents, and responses to receptor-specific ligands for endothelin and natriuretic peptide receptors suggest that B-type endothelin receptors are expressed in both vessels and that the artery expresses both A- and B-type natriuretic peptide receptors; however, the vein (like the ventral aorta) expresses only the B-type natriuretic peptide receptor. My data suggest that a suite of signaling systems is ubiquitous in both arteries and veins in at least this elasmobranch species. Their role in hemodynamics and osmoregulation (perfusion of gill and rectal gland) remains to be determined.

  18. [Experimental study on two-way application of traditional Chinese medicines capable of promoting blood circulation and removing blood stasis with neutral property in cold and hot blood stasis syndrome I].

    Science.gov (United States)

    Hao, Er-Wei; Deng, Jia-Gang; Du, Zheng-Cai; Yan, Ke; Zheng, Zuo-Wen; Wang, Qin; Huang, Li-Zhen; Bao, Chuan-Hong; Deng, Xiu-Qiong; Lu, Xiao-Yan; Tang, Zhi-Ling

    2012-11-01

    To study the action characteristics of "two-way application and conditioned dominance" of traditional Chinese medicines with neutral property by observing the action characteristic of 10 traditional Chinese medicines capable of promoting blood circulation and removing blood stasis with neutral property in the microcirculation in rats with heat stagnation and blood stasis syndrome. The rat model with heat stagnation and blood stasis syndrome was established by injecting carrageenan and dry yeast, and the rat model with cold stagnation and blood stasis syndrome was built by the body freezing method. Ten traditional Chinese medicines with neutral property, including 5 with hot property and 5 with cold property, were selected for intervention to observe blood flow rate and flow state indicators in rat auricles and make a comparative analysis on action characteristics of traditional Chinese medicines with neutral property. ANOVA showed that among the 10 traditional Chinese medicines with neutral property, 6 such as Typhae Pollen, Sappan Lignum and Vaccariae Semen can obviously increase the blood flow rate (P traditional Chinese medicines with cold property can increase the blood flow rate (P medicines showed no notable effect; among the 5 traditional Chinese medicines with hot property, Carthamus tinctorius and Ligusticum chuanxiong can increase the blood flow rate (P traditional Chinese medicines with natural and cold properties showed similar effect on heat stagnation and blood stasis syndrome and better effect in increasing blood flow rate than those with hot property; those with natural and hot properties showed similar effect and better effect in increasing blood flow rate than those with cold property. Under the condition of heat stagnation and blood stasis syndrome, traditional Chinese medicines with neutral property have the similar action characteristics with those with cold property; wile under the condition of cold stagnation and blood stasis syndrome

  19. Design characteristics of pantograph type in vessel fuel handling system in SFR

    International Nuclear Information System (INIS)

    Kim, S. H.; Koo, G. H.

    2012-01-01

    The pantograph type in vessel fuel handling system in a sodium cooled fast reactor (SFR), which requires installation space for the slot in the upper internal structure attached under the rotating plug, is composed of an in vessel transfer machine (IVTM), a single rotating plug, in vessel storage, and a fuel transfer port (FTP). The pantograph type IVTM can exchange fuel assemblies through a slot, the design requirement of which should be essentially considered in the design of the in vessel fuel handling system. In addition, the spent fuel assemblies temporarily stored in the in vessel storage of the reactor vessel are removed to the outside of the reactor vessel through the FTP. The fuel transfer basket is then provided in the FTP, and a fuel transfer is performed by using it. In this study, the design characteristics for a pantograph type in vessel fuel handling system are reviewed, and the preconceptual designs are studied

  20. Design characteristics of pantograph type in vessel fuel handling system in SFR

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. H.; Koo, G. H. [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    The pantograph type in vessel fuel handling system in a sodium cooled fast reactor (SFR), which requires installation space for the slot in the upper internal structure attached under the rotating plug, is composed of an in vessel transfer machine (IVTM), a single rotating plug, in vessel storage, and a fuel transfer port (FTP). The pantograph type IVTM can exchange fuel assemblies through a slot, the design requirement of which should be essentially considered in the design of the in vessel fuel handling system. In addition, the spent fuel assemblies temporarily stored in the in vessel storage of the reactor vessel are removed to the outside of the reactor vessel through the FTP. The fuel transfer basket is then provided in the FTP, and a fuel transfer is performed by using it. In this study, the design characteristics for a pantograph type in vessel fuel handling system are reviewed, and the preconceptual designs are studied.

  1. A Review of Algorithms for Retinal Vessel Segmentation

    Directory of Open Access Journals (Sweden)

    Monserrate Intriago Pazmiño

    2014-10-01

    Full Text Available This paper presents a review of algorithms for extracting blood vessels network from retinal images. Since retina is a complex and delicate ocular structure, a huge effort in computer vision is devoted to study blood vessels network for helping the diagnosis of pathologies like diabetic retinopathy, hypertension retinopathy, retinopathy of prematurity or glaucoma. To carry out this process many works for normal and abnormal images have been proposed recently. These methods include combinations of algorithms like Gaussian and Gabor filters, histogram equalization, clustering, binarization, motion contrast, matched filters, combined corner/edge detectors, multi-scale line operators, neural networks, ants, genetic algorithms, morphological operators. To apply these algorithms pre-processing tasks are needed. Most of these algorithms have been tested on publicly retinal databases. We have include a table summarizing algorithms and results of their assessment.

  2. Fuel removing method for high burnup fuel and device therefor

    International Nuclear Information System (INIS)

    Terakado, Shogo; Owada, Isao; Kanno, Yoshio; Aizawa, Sakue; Yamahara, Takeshi.

    1993-01-01

    A through hole is perforated at the center of a fuel rod in a cladding tube by a diamond drill in a water vessel. Further, the through hole is enlarged by the diamond drill. A pellet removing tool is attached to a drill chuck instead of the diamond drill. Then, the thin cylindrical fuel pellet remaining on the inner surface of the cladding tube is removed by using a pellet removing tool while applying vibrations. Subsequently, a wire brush having a slightly larger diameter than that of the inner diameter of the cladding tube is attached to the drill chuck and rotated to finish the inner surface, so that a small amount of pellets remained on the inner surface of the cladding tube is removed. Pellet powders in the water vessel are collected and recovered to the water container. This can remove high burnup fuels which are firmly sticked to the cladding tube, without giving thermal or mechanical influences on the cladding tube. (I.N.)

  3. Confinement Vessel Assay System: Design and Implementation Report

    International Nuclear Information System (INIS)

    Frame, Katherine C.; Bourne, Mark M.; Crooks, William J.; Evans, Louise; Mayo, Douglas R.; Gomez, Cipriano D.; Miko, David K.; Salazar, William R.; Stange, Sy; Vigil, Georgiana M.

    2012-01-01

    Los Alamos National Laboratory has a number of spherical confinement vessels remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1- to 2-inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the vessels. We have developed a neutron assay system for the purposes of Materials Control and Accountability (MC and A) measurements of the vessel prior to and after cleanout. We present our approach to confronting the challenges in designing, building, and testing such a system. The system was designed to meet a set of functional and operational requirements. A Monte Carlo model was developed to aid in optimizing the detector design as well as to predict the systematic uncertainty associated with confinement vessel measurements. Initial testing was performed to optimize and determine various measurement parameters, and then the system was characterized using 252 Cf placed a various locations throughout the measurement system. Measurements were also performed with a 252 Cf source placed inside of small steel and HDPE shells to study the effect of moderation. These measurements compare favorably with their MCNPX model equivalent, making us confident that we can rely on the Monte Carlo simulation to predict the systematic uncertainty due to variations in response to material that may be localized at different points within a vessel.

  4. Extravasal occlusion of large vessels with titanic clips: efficiency, indications, and contraindications.

    Science.gov (United States)

    Vasilenko, Yu V; Kim, A I; Kotov, S A

    2002-11-01

    The mechanism of extravasal occlusion of blood vessels with titanic clips "Atrauclip" and "Ligaclip extra" was studied in order to reveal indications and contraindications to their use. Occlusion with the clips of both types was ineffective in vessels with a diameter of >7.0 mm. Arteritis or the presence of an intravascular occlusion facility in the vessel were also the contraindications for clip occlusion. In overcases the procedure of occlusion with titanic clips was efficient and atraumatic.

  5. Hybrid Segmentation of Vessels and Automated Flow Measures in In-Vivo Ultrasound Imaging

    DEFF Research Database (Denmark)

    Moshavegh, Ramin; Martins, Bo; Hansen, Kristoffer Lindskov

    2016-01-01

    Vector Flow Imaging (VFI) has received an increasing attention in the scientific field of ultrasound, as it enables angle independent visualization of blood flow. VFI can be used in volume flow estimation, but a vessel segmentation is needed to make it fully automatic. A novel vessel segmentation...

  6. Careful treatment planning enables safe ablation of liver tumors adjacent to major blood vessels by percutaneous irreversible electroporation (IRE).

    Science.gov (United States)

    Kos, Bor; Voigt, Peter; Miklavcic, Damijan; Moche, Michael

    2015-09-01

    Irreversible electroporation (IRE) is a tissue ablation method, which relies on the phenomenon of electroporation. When cells are exposed to a sufficiently electric field, the plasma membrane is disrupted and cells undergo an apoptotic or necrotic cell death. Although heating effects are known IRE is considered as non-thermal ablation technique and is currently applied to treat tumors in locations where thermal ablation techniques are contraindicated. The manufacturer of the only commercially available pulse generator for IRE recommends a voltage-to-distance ratio of 1500 to 1700 V/cm for treating tumors in the liver. However, major blood vessels can influence the electric field distribution. We present a method for treatment planning of IRE which takes the influence of blood vessels on the electric field into account; this is illustrated on a treatment of 48-year-old patient with a metastasis near the remaining hepatic vein after a right side hemi-hepatectomy. Output of the numerical treatment planning method shows that a 19.9 cm3 irreversible electroporation lesion was generated and the whole tumor was covered with at least 900 V/cm. This compares well with the volume of the hypodense lesion seen in contrast enhanced CT images taken after the IRE treatment. A significant temperature raise occurs near the electrodes. However, the hepatic vein remains open after the treatment without evidence of tumor recurrence after 6 months. Treatment planning using accurate computer models was recognized as important for electrochemotherapy and irreversible electroporation. An important finding of this study was, that the surface of the electrodes heat up significantly. Therefore the clinical user should generally avoid placing the electrodes less than 4 mm away from risk structures when following recommendations of the manufacturer.

  7. Development of remote welding equipment and techniques for the TFTR vacuum vessel

    International Nuclear Information System (INIS)

    Masson, L.S.; Watts, K.D.; Larson, R.A.; Aldrich, W.C.

    1980-01-01

    In the event that the TFTR vacuum vessel is damaged or one of the toroidal field coils fails after the system has become substantially activated, it is necessary to remotely remove and replace the damaged section of the vessel using remote handling procedures. This paper describes a welding system developed through the final design stage to perform the remote welding necessary during the replacement operation. Information is presented describing the vessel configuration, the replacement sequence, the welding system requirements, welder configuration, supporting systems, the weld development program and future development requirements

  8. In silico particle margination in blood flow

    OpenAIRE

    Müller, Kathrin

    2015-01-01

    A profound knowledge of margination, the migration of blood components to the vessel wall in blood flow, is required in order to understand the genesis of various diseases, as e.g., cardiovascular diseases or bleeding disorders. Margination of particles is a pre-condition for potential adhesion. Adhesion to the vessel wall is required for platelets, the protein von Willebrand factor (VWF), but also for drug and imaging agent carriers in order to perform their particular tasks. In the haemosta...

  9. Tumor vessel normalization by the PI3K inhibitor HS-173 enhances drug delivery.

    Science.gov (United States)

    Kim, Soo Jung; Jung, Kyung Hee; Son, Mi Kwon; Park, Jung Hee; Yan, Hong Hua; Fang, Zhenghuan; Kang, Yeo Wool; Han, Boreum; Lim, Joo Han; Hong, Soon-Sun

    2017-09-10

    Tumor vessels are leaky and immature, which causes poor oxygen and nutrient supply to tumor vessels and results in cancer cell metastasis to distant organs. This instability of tumor blood vessels also makes it difficult for anticancer drugs to penetrate and reach tumors. Numerous tumor vessel normalization approaches have been investigated for improving drug delivery into tumors. In this study, we investigated whether phosphoinositide 3-kinase (PI3K) inhibitors are able to improve vascular structure and function over the prolonged period necessary to achieve effective vessel normalization. The PI3K inhibitors, HS-173 and BEZ235 potently suppressed tumor growth and hypoxia, and increased tumor apoptosis in animal models. PI3K inhibitors also induced a regular, flat monolayer of endothelial cells (ECs) in vessels, improving stability of vessel structure, and normalized tumor vessels by increasing vascular maturity, pericyte coverage, basement membrane thickness, and tight-junctions. These effects resulted in a decrease in tumor vessel tortuosity and vessel thinning, and improved vessel function and blood flow. The tumor vessel stabilization effect of the PI3K inhibitor HS-173 also decreased the number of metastatic lung nodules in vivo metastasis model. Furthermore, HS-173 improved the delivery of doxorubicin into the tumor region, enhancing its anticancer effects. Mechanistic studies suggested that PI3K inhibitor HS-173-induced vessel normalization reflected changes in endothelial Notch signaling. Taken together, our findings indicate that vessel normalization by PI3K inhibitors restrained tumor growth and metastasis while improving chemotherapy by enhancing drug delivery into the tumor, suggesting that HS-173 may have a therapeutic value as an enhancer or an anticancer drug. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Direct bolus imaging of cervical blood vessels by means of MRI

    International Nuclear Information System (INIS)

    Satoh, Toshihiko; Fujioka, Mutsuhisa; Watari, Tsutomu; Nishimura, Gen; Matsumoto, Toshihiko; Washiya, Sumio; Inoue, Kiyoshi; Horita, Masatoshi; Shimizu, Kohji.

    1991-01-01

    Direct bolus imaging (DBI) is one of the non-invasive method for flow measurements which is based on the bolus tracking technique. DBI permits the direct visualization of flow velocity profiles and vessel band width. We performed screening for cervical vessel disease in patients with vertigo by means of DBI. MR system used here was 0.5 T superconducting imager-SMT-50A (Shimazu Co. Ltd). Pulse sequence parameters were TR= 60 ms, TE= 50 ms, NEX= 1, acquisition matrix; 128 x 256, slice thickness= 5 mm, with cardiac gating. Pulse sequence employed a slice selective RF pulse at the level of C5 vertebral body to tag a disk of fluid perpendicular to the direction of flow, followed by a gradient reforcussed echo. We evaluated each peak high and band width of the common-carotid arteries and the vertebral arteries. Seventy nine of 83 cases had optimal examinations. Abnormal findings of DBI were seen in 15 of 79 cases, (including 2 of subclavian steal syndrome, 1 of carotid obstruction, 5 of vertebral obstruction, 1 of basilar artery obstruction, and 6 of hypoplasia of vertebral artery). The abnormal findings of DBI were well correlated with those of angiographic examinations. We concluded that DBI was suitable to the screening for cervical vessel diseases in patients with vertigo, and should be added to the routine MR studies. (author)

  11. Vascular Canals in Permanent Hyaline Cartilage: Development, Corrosion of Nonmineralized Cartilage Matrix, and Removal of Matrix Degradation Products.

    Science.gov (United States)

    Gabner, Simone; Häusler, Gabriele; Böck, Peter

    2017-06-01

    Core areas in voluminous pieces of permanent cartilage are metabolically supplied via vascular canals (VCs). We studied cartilage corrosion and removal of matrix degradation products during the development of VCs in nose and rib cartilage of piglets. Conventional staining methods were used for glycosaminoglycans, immunohistochemistry was performed to demonstrate collagens types I and II, laminin, Ki-67, von Willebrand factor, VEGF, macrophage marker MAC387, S-100 protein, MMPs -2,-9,-13,-14, and their inhibitors TIMP1 and TIMP2. VCs derived from connective tissue buds that bulged into cartilage matrix ("perichondrial papillae", PPs). Matrix was corroded at the tips of PPs or resulting VCs. Connective tissue stromata in PPs and VCs comprised an axial afferent blood vessel, peripherally located wide capillaries, fibroblasts, newly synthesized matrix, and residues of corroded cartilage matrix (collagen type II, acidic proteoglycans). Multinucleated chondroclasts were absent, and monocytes/macrophages were not seen outside the blood vessels. Vanishing acidity characterized areas of extracellular matrix degradation ("preresorptive layers"), from where the dismantled matrix components diffused out. Leached-out material stained in an identical manner to intact cartilage matrix. It was detected in the stroma and inside capillaries and associated downstream veins. We conclude that the delicate VCs are excavated by endothelial sprouts and fibroblasts, whilst chondroclasts are specialized to remove high volumes of mineralized cartilage. VCs leading into permanent cartilage can be formed by corrosion or inclusion, but most VCs comprise segments that have developed in either of these ways. Anat Rec, 300:1067-1082, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  12. Investigation of the blood behaviour and vascular diseases by using mathematical physic principles

    Science.gov (United States)

    Yardimci, Ahmet; Simsek, Buket

    2017-07-01

    In this paper we prepare a short survey for using of mathematical physic principles in blood flow and vascular diseases researches. The study of the behavior of blood flow in the blood vessels provides understanding on connection between flow and the development of dieseases such as atherosclerosis, thrombosis, aneurysms etc. and how the flow dynamics is changed under these conditions. Blood flow phenomena are often too complex that it would be possible to describe them entirely analytically, although simple models, such as Poiseuille model, can still provide some insight into blood flow. Blood is not an "ideal fluid" and energy is lost as flowing blood overcomes resistance. Resistance to blood flow is a function of viscosity, vessel radius, and vessel length. So, mathematical Physic principles are useful tools for blood flow research studies. Blood flow is a function of pressure gradient and resistance and resistance to flow can be estimates using Poiseuille's law. Reynold's number can be used to determine whether flow is laminar or turbulent.

  13. Evaluation of Peripheral Blood Circulation Disorder in Scleroderma Patients Using an Optical Sensor with a Pressurization Mechanism.

    Directory of Open Access Journals (Sweden)

    Yoshiki Yamakoshi

    Full Text Available Blood circulation function of peripheral blood vessels in skin dermis was evaluated employing an optical sensor with a pressurization mechanism using the blood outflow and reflow characteristics. The device contains a light source and an optical sensor. When applied to the skin surface, it first exerts the primary pressure (higher than the systolic blood pressure, causing an outflow of blood from the dermal peripheral blood vessels. After two heartbeats, the pressure is lowered (secondary pressure and blood reflows into the peripheral blood vessels. Hemoglobin concentration, which changes during blood outflow and reflow, is derived from the received light intensity using the Beer-Lambert law. This method was evaluated in 26 healthy female volunteers and 26 female scleroderma patients. In order to evaluate the blood circulation function of the peripheral blood vessels of scleroderma patients, pressurization sequence which consists of primary pressure followed by secondary pressure was adopted. Blood reflow during the first heartbeat period after applying the secondary pressure of 40mmHg was (mean±SD 0.059±0.05%mm for scleroderma patients and 0.173±0.104%mm for healthy volunteers. Blood reflow was significantly lower in scleroderma patients than in healthy volunteers (p<0.05. This result indicates that the information necessary for assessing blood circulation disorder of peripheral blood vessels in scleroderma patients is objectively obtained by the proposed method.

  14. Hypercholesterolemia induced cerebral small vessel disease.

    Science.gov (United States)

    Kraft, Peter; Schuhmann, Michael K; Garz, Cornelia; Jandke, Solveig; Urlaub, Daniela; Mencl, Stine; Zernecke, Alma; Heinze, Hans-Jochen; Carare, Roxana O; Kleinschnitz, Christoph; Schreiber, Stefanie

    2017-01-01

    While hypercholesterolemia plays a causative role for the development of ischemic stroke in large vessels, its significance for cerebral small vessel disease (CSVD) remains unclear. We thus aimed to understand the detailed relationship between hypercholesterolemia and CSVD using the well described Ldlr-/- mouse model. We used Ldlr-/- mice (n = 16) and wild-type (WT) mice (n = 15) at the age of 6 and 12 months. Ldlr-/- mice develop high plasma cholesterol levels following a high fat diet. We analyzed cerebral capillaries and arterioles for intravascular erythrocyte accumulations, thrombotic vessel occlusions, blood-brain barrier (BBB) dysfunction and microbleeds. We found a significant increase in the number of erythrocyte stases in 6 months old Ldlr-/- mice compared to all other groups (P hypercholesterolemia is related to a thrombotic CSVD phenotype, which is different from hypertension-related CSVD that associates with a hemorrhagic CSVD phenotype. Our data demonstrate a relationship between hypercholesterolemia and the development of CSVD. Ldlr-/- mice appear to be an adequate animal model for research into CSVD.

  15. Investigations of the mechanism of vitamin E removal from blood and the effect of NO2 on the pulmonary uptake of vitamin E

    International Nuclear Information System (INIS)

    Gardner, H.K.

    1987-01-01

    To examine the effect of NO 2 on vitamin E uptake by lung, we first investigated the mechanism of removal of vitamin E from blood. To accomplish this, a method for labeling serum with tritiated vitamin E was developed. Two other lipids, whose uptake is better understood, were also studied, and compared with vitamin E. Tritiated triacylglycerol was used to monitor lipoprotein lipase-mediated uptake, while tritiated cholesterol was used to monitor LDL receptor-mediated uptake. Blood curves derived from untreated, adult, male, Long-Evans rats indicated that all three lipids were removed biexponentially. The half-life for the Rapid component was 2.5-3.7 minutes for all lipids. The slower curve had half-lives of 42.3 minutes for triacylglycerol, 990.0 minutes for cholesterol, and 288.8 minutes for vitamin E. Biological screening of labeled serum demonstrated that the faster process was not simply the removal of lipoproteins damaged by the labeling process. Hepatectomy affected the rate of neither triacylglycerol nor cholesterol removal, but did slow vitamin E uptake, suggesting a distinct role for liver in vitamin E extraction

  16. Performance of the prism reactor's passive decay heat removal system

    International Nuclear Information System (INIS)

    Magee, P.M.; Hunsbedt, A.

    1989-01-01

    The PRISM modular reactor concept has a totally passive safety-grade decay heat removal system referred to as the Reactor Vessel Auxiliary Cooling System (RVACS) that rejects heat from the reactor by radiation and natural convection of air. The system is inherently reliable and is not subject to the failure modes commonly associated with active cooling systems. The thermal performance of RVACS exceeds requirements and significant thermal margins exist. RVACS has been shown to perform its function under many postulated accident conditions. The PRISM power plant is equipped with three methods for shutdown: condenser cooling in conjunction with intermediate sodium and steam generator systems, and auxiliary cooling system (ACS) which removes heat from the steam generator by natural convection of air and transport of heat from the core by natural convection in the primary and intermediate systems, and a safety- grade reactor vessel auxiliary cooling system (RVACS) which removes heat passively from the reactor containment vessel by natural convection of air. The combination of one active and two passive systems provides a highly reliable and economical shutdown heat removal system. This paper provides a summary of the RVACS thermal performance for expected operating conditions and postulated accident events. The supporting experimental work, which substantiates the performance predictions, is also summarized

  17. Microscopical and elemental FESEM and Phenom ProX-SEM-EDS analysis of osteocyte- and blood vessel-like microstructures obtained from fossil vertebrates of the Eocene Messel Pit, Germany.

    Science.gov (United States)

    Cadena, Edwin

    2016-01-01

    The Eocene (∾48 Ma) Messel Pit in Germany is a UNESCO World Heritage Site because of its exceptionally preserved fossils, including vertebrates, invertebrates, and plants. Messel fossil vertebrates are typically characterized by their articulated state, and in some cases the skin, hair, feathers, scales and stomach contents are also preserved. Despite the exceptional macroscopic preservation of Messel fossil vertebrates, the microstructural aspect of these fossils has been poorly explored. In particular, soft tissue structures such as hair or feathers have not been chemically analyzed, nor have bone microstructures. I report here the preservation and recovery of osteocyte-like and blood vessel-like microstructures from the bone of Messel Pit specimens, including the turtles Allaeochelys crassesculpta and Neochelys franzeni, the crocodile Diplocynodon darwini, and the pangolin Eomanis krebsi. I used a Field Emission Scanning Electron Microscope (FESEM) and a Phenom ProX desktop scanning electron microscope (LOT-QuantumDesign) equipped with a thermionic CeB6 source and a high sensitivity multi-mode backscatter electron (BSE) for microscopical and elemental characterization of these bone microstructures. Osteocyte-like and blood vessel-like microstructures are constituted by a thin layer (∾50 nm thickness), external and internal mottled texture with slightly marked striations. Circular to linear marks are common on the external surface of the osteocyte-like microstructures and are interpreted as microbial troughs. Iron (Fe) is the most abundant element found in the osteocyte-like and blood vessel-like microstructures, but not in the bone matrix or collagen fibril-like microstructures. The occurrence of well-preserved soft-tissue elements (at least their physical form) establishes a promising background for future studies on preservation of biomolecules (proteins or DNA) in Messel Pit fossils.

  18. Microscopical and elemental FESEM and Phenom ProX-SEM-EDS analysis of osteocyte- and blood vessel-like microstructures obtained from fossil vertebrates of the Eocene Messel Pit, Germany

    Directory of Open Access Journals (Sweden)

    Edwin Cadena

    2016-01-01

    Full Text Available The Eocene (∾48 Ma Messel Pit in Germany is a UNESCO World Heritage Site because of its exceptionally preserved fossils, including vertebrates, invertebrates, and plants. Messel fossil vertebrates are typically characterized by their articulated state, and in some cases the skin, hair, feathers, scales and stomach contents are also preserved. Despite the exceptional macroscopic preservation of Messel fossil vertebrates, the microstructural aspect of these fossils has been poorly explored. In particular, soft tissue structures such as hair or feathers have not been chemically analyzed, nor have bone microstructures. I report here the preservation and recovery of osteocyte-like and blood vessel-like microstructures from the bone of Messel Pit specimens, including the turtles Allaeochelys crassesculpta and Neochelys franzeni, the crocodile Diplocynodon darwini, and the pangolin Eomanis krebsi. I used a Field Emission Scanning Electron Microscope (FESEM and a Phenom ProX desktop scanning electron microscope (LOT-QuantumDesign equipped with a thermionic CeB6 source and a high sensitivity multi-mode backscatter electron (BSE for microscopical and elemental characterization of these bone microstructures. Osteocyte-like and blood vessel-like microstructures are constituted by a thin layer (∾50 nm thickness, external and internal mottled texture with slightly marked striations. Circular to linear marks are common on the external surface of the osteocyte-like microstructures and are interpreted as microbial troughs. Iron (Fe is the most abundant element found in the osteocyte-like and blood vessel-like microstructures, but not in the bone matrix or collagen fibril-like microstructures. The occurrence of well-preserved soft-tissue elements (at least their physical form establishes a promising background for future studies on preservation of biomolecules (proteins or DNA in Messel Pit fossils.

  19. Effects of angiopoietin-1 on inflammatory injury in endothelial progenitor cells and blood vessels.

    Science.gov (United States)

    Wang, Yi-Qing; Song, Jing-Jin; Han, Xiao; Liu, Yi-Ye; Wang, Xi-Huang; Li, Zhi-Ming; Tzeng, Chi-Meng

    2014-01-01

    Endothelial progenitor cells (EPCs) and angiopoietin-1 (Ang-1) play important roles in vasculogenesis and angiogenesis, respectively. Thus, targeting both aspects of cardiovascular tissue regeneration may offer promising therapeutic options for cardiovascular disorders. To this end, we constructed a lentiviral vector (pNL) with the Ang-1 gene and transfected EPCs with it (Ang-1-EPCs) to investigate vasculogenesis in both cellular and animal models. Compared to controls, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) increased significantly in both untreated EPCs and in the pNL vector group. After Ang-1 transcription, ICAM-1 and VCAM-1 decreased considerably in those treatment groups. Ang-1-modified EPCs alleviated inflammatory responses induced by tumor-necrosis factor-α (TNF-α) in vitro. Moreover, Ang-1-EPC implantation inhibited neointimal hyperplasia after balloon catheter injury in rats, dramatically diminishing the intimal-media (I/M) ratio and decreasing the neointimal area. Proliferating cell nuclear antigen expression in the Ang-1-EPC group was lower than the EPC non-treatment group as well, suggesting that Ang-1-EPC improved cell survival during inflammation and promoted endothelialization in damaged blood vessels.

  20. After-heat removing device

    International Nuclear Information System (INIS)

    Iwashige, Kengo; Otsuka, Masaya; Yokoyama, Iwao; Yamakawa, Masanori.

    1990-01-01

    The present invention concerns an after-heat removing device for first reactors. A heat accumulation portion provided in a cooling channel of an after-heat removing device is disposed before a coil-like heat conduction pipe for cooling of the after-heat removing device. During normal reactor operation, the temperature in the heat accumulation portion is near the temperature of the high temperature plenum due to heat conduction and heat transfer from the high temperature plenum. When the reactor is shutdown and the after-heat removing device is started, coolants cooled in the air cooler start circulation. The coolants arriving at the heat accumulation portion deprive heat from the heat accumulation portion and, ion turn, increase their temperature and then reach the cooling coil. Subsequently, the heat calorie possessed in the heat accumulation portion is reduced and the after-heat removing device is started for the operation at a full power. This can reduce the thermal shocks applied to the cooling coil or structures in a reactor vessel upon starting the after-heat removing device. (I.N.)

  1. Fission product aerosol removal test by containment spray under accident management conditions (3)

    International Nuclear Information System (INIS)

    Watanabe, Atsushi; Nagasaka, Hideo; Yokobori, Seiichi; Akinaga, Makoto

    2000-01-01

    In order to demonstrate the effective FP aerosol removal by containment spray under Japanese AM conditions, two system integral tests and two separate effect tests were carried out using a full-height simulation test facility. In case of PWR LOCA, aerosol concentration in the upper containment vessel decreased even under low spray flow rate. In case of BWR LOCA with water injection into RPV, the aerosol concentration in the entire vessel also decreased rapidly after aerosol supply stopping. In both cases, the removal rate estimated from the NUREG-1465 was coincided with test results. The aerosol washing effect by spray was confirmed to be predominant by conducting suppression chamber isolation test. It turned out that the effect of aerosol solubility and density on aerosol removal by spray was quite small by conducting insoluble aerosol injection test. After the modification of aerosol removal model by the spray and hygroscopic aerosol model in original MELCOR 1.8.4, calculated aerosol concentration transient in the containment vessel agreed well with the test data. (author)

  2. MR angiography of the cerebral vessels with inflow-increased visualization by overcontiguous imaging and advanced processing

    International Nuclear Information System (INIS)

    McLachian, S.; Simon, H.E.; de Graaf, R.; Ho, A.M.; Ruccio, W.J.; Steidley, J.W.; Pradhan, R.B.

    1989-01-01

    The purpose of this study was to increase the visualization of cerebral vessels with MR angiography by using an inflow technique from transverse sections. Difficulties with visualization include the tortuous nature of the vessels and slow blood flow. The MR method is a transverse two-dimensional multiple single-section sequence with a velocity-compensated gradient echo and presaturation. A S15 imager with 10-mTm gradients and a prototype angiographic package is used. Overcontiguous acquisition yields smaller effective center-to-center sections. Interpolation is used to generate interleaved plane projections. A combination of image parameter swill reduce the level of the stationary tissue relative to the flowing blood. For vessels that are not perpendicular to the section, overlapping the sections by 25%--33% is shown to reduce the staircase appearance without affecting the apparent size of the vessels. Interpolation of the MR images will further reduce this artifact, giving the vessels a smooth structure. MR angiography of the brain performed with an inflow technique allows the visualization of vessels in the brain even if the vessels follow tortuous paths. Presaturation and user-defined regions of interest can be used for ease of interpretation

  3. PULPAL BLOOD FLOW CHANGES IN ABUTMENT TEETH OF REMOVABLE PARTIAL DENTURES

    Science.gov (United States)

    Kunt, Göknil Ergün; Kökçü, Deniz; Ceylan, Gözlem; Yılmaz, Nergiz; Güler, Ahmet Umut

    2009-01-01

    The purpose of this study was to investigate the effect of tooth supported (TSD) and toothtissue supported (TTSD) removable partial denture wearing on pulpal blood flow (PBF) of the abutment teeth by using Laser Doppler Flowmeter (LDF). Measurements were carried out on 60 teeth of 28 patients (28 teeth and 12 patients of TTSD group, 32 teeth and 16 patients of TSD group) who had not worn any type of removable partial dentures before, had no systemic problems and were non smokers. PBF values were recorded by LDF before insertion (day 0) and after insertion of dentures at day 1, day 7 and day 30. Statistical analysis was performed by student t test and covariance analyses of repeated measurements. In the group TTSD, the mean values of PBF decreased statistically significantly at day 1 after insertion when compared with PBF values before insertion (p<0,01). There was no statistically significant difference among PBF mean values on 1st, 7th and 30th day. However, in the group TSD, there was no statistically significant difference among PBF mean values before insertion and on 1st, 7th and 30th day. In other words, PBF mean values in group TSD continued without changing statistically significant on 1st, 7th and 30th day. TTSD wearing may show negative effect on the abutment teeth due to decreasing basal PBF. PMID:20001995

  4. Pulpal blood flow changes in abutment teeth of removable partial dentures

    Directory of Open Access Journals (Sweden)

    Göknil Ergün Kunt

    2009-11-01

    Full Text Available The purpose of this study was to investigate the effect of tooth supported (TSD and toothtissue supported (TTSD removable partial denture wearing on pulpal blood flow (PBF of the abutment teeth by using Laser Doppler Flowmeter (LDF.Measurements were carried out on 60 teeth of 28 patients (28 teeth and 12 patients of TTSD group, 32 teeth and 16 patients of TSD group who had not worn any type of removable partial dentures before, had no systemic problems and were non smokers. PBF values were recorded by LDF before insertion (day 0 and after insertion of dentures at day 1, day 7 and day 30. Statistical analysis was performed by student t test and covariance analyses of repeated measurements.In the group TTSD, the mean values of PBF decreased statistically significantly at day 1 after insertion when compared with PBF values before insertion (p<0,01. There was no statistically significant difference among PBF mean values on 1st, 7th and 30th day. However, in the group TSD, there was no statistically significant difference among PBF mean values before insertion and on 1st, 7th and 30th day. In other words, PBF mean values in group TSD continued without changing statistically significant on 1st, 7th and 30th day.TTSD wearing may show negative effect on the abutment teeth due to decreasing basal PBF.

  5. Vessel Enhancement and Segmentation of 4D CT Lung Image Using Stick Tensor Voting

    Science.gov (United States)

    Cong, Tan; Hao, Yang; Jingli, Shi; Xuan, Yang

    2016-12-01

    Vessel enhancement and segmentation plays a significant role in medical image analysis. This paper proposes a novel vessel enhancement and segmentation method for 4D CT lung image using stick tensor voting algorithm, which focuses on addressing the vessel distortion issue of vessel enhancement diffusion (VED) method. Furthermore, the enhanced results are easily segmented using level-set segmentation. In our method, firstly, vessels are filtered using Frangi's filter to reduce intrapulmonary noises and extract rough blood vessels. Secondly, stick tensor voting algorithm is employed to estimate the correct direction along the vessel. Then the estimated direction along the vessel is used as the anisotropic diffusion direction of vessel in VED algorithm, which makes the intensity diffusion of points locating at the vessel wall be consistent with the directions of vessels and enhance the tubular features of vessels. Finally, vessels can be extracted from the enhanced image by applying level-set segmentation method. A number of experiments results show that our method outperforms traditional VED method in vessel enhancement and results in satisfied segmented vessels.

  6. Cleaning, disassembly, and requalification of the FFTF in vessel handling machine

    International Nuclear Information System (INIS)

    Coops, W.J.

    1977-10-01

    The Engineering Model In Vessel Handling Machine (IVHM) was successfully removed, cleaned, disassembled, inspected, reassembled and reinstalled into the sodium test vessel at Richland, Washington. This was the first time in the United States a full size operational sodium wetted machine has been cleaned by the water vapor nitrogen process and requalified for operation. The work utilized an atmospheric control system during removal, a tank type water vapor nitrogen cleaning system and an open ''hands on'' disassembly and assembly stand. Results of the work indicate the tools, process and equipment are adequate for the non-radioactive maintenance sequence. Additionally, the work proves that a machine of this complexity can be successfully cleaned, maintained and re-used without the need to replace a large percentage of the sodium wetted parts

  7. Nuclear power plant equipped with hydrogen removing system

    International Nuclear Information System (INIS)

    Ezawa, Shin-ichi; Yamanari, Shozo; Okura, Minoru; Kamizuma, Nobuaki.

    1998-01-01

    A γ-shield and container spray pipelines are disposed to an upper dry well in a reactor container incorporating a reactor pressure vessel. A plurality of catalytic hydrogen removing devices are disposed close to a wall on the side of the pressure vessel in the dry well and a wall on the side of the outer wall of the reactor container. The plurality of catalytic hydrogen removing devices are disposed substantially equally in horizontal direction and circumferential direction of the side walls. If container spray water is sprayed, the atmospheric gases in the reactor are compulsory circulated. In addition, since the temperature of the γ-shield is higher than the atmospheric temperature, spontaneous circulation is caused. As a result, rising currents of gases are formed at regions in the vicinity of the γ-shield. The catalytic hydrogen removing devices are disposed to the places where the rising currents are formed. (I.N.)

  8. Lung vessel segmentation in CT images using graph-cuts

    Science.gov (United States)

    Zhai, Zhiwei; Staring, Marius; Stoel, Berend C.

    2016-03-01

    Accurate lung vessel segmentation is an important operation for lung CT analysis. Filters that are based on analyzing the eigenvalues of the Hessian matrix are popular for pulmonary vessel enhancement. However, due to their low response at vessel bifurcations and vessel boundaries, extracting lung vessels by thresholding the vesselness is not sufficiently accurate. Some methods turn to graph-cuts for more accurate segmentation, as it incorporates neighbourhood information. In this work, we propose a new graph-cuts cost function combining appearance and shape, where CT intensity represents appearance and vesselness from a Hessian-based filter represents shape. Due to the amount of voxels in high resolution CT scans, the memory requirement and time consumption for building a graph structure is very high. In order to make the graph representation computationally tractable, those voxels that are considered clearly background are removed from the graph nodes, using a threshold on the vesselness map. The graph structure is then established based on the remaining voxel nodes, source/sink nodes and the neighbourhood relationship of the remaining voxels. Vessels are segmented by minimizing the energy cost function with the graph-cuts optimization framework. We optimized the parameters used in the graph-cuts cost function and evaluated the proposed method with two manually labeled sub-volumes. For independent evaluation, we used 20 CT scans of the VESSEL12 challenge. The evaluation results of the sub-volume data show that the proposed method produced a more accurate vessel segmentation compared to the previous methods, with F1 score 0.76 and 0.69. In the VESSEL12 data-set, our method obtained a competitive performance with an area under the ROC curve of 0.975, especially among the binary submissions.

  9. Fast vessel segmentation in retinal images using multi-scale enhancement and second-order local entropy

    Science.gov (United States)

    Yu, H.; Barriga, S.; Agurto, C.; Zamora, G.; Bauman, W.; Soliz, P.

    2012-03-01

    Retinal vasculature is one of the most important anatomical structures in digital retinal photographs. Accurate segmentation of retinal blood vessels is an essential task in automated analysis of retinopathy. This paper presents a new and effective vessel segmentation algorithm that features computational simplicity and fast implementation. This method uses morphological pre-processing to decrease the disturbance of bright structures and lesions before vessel extraction. Next, a vessel probability map is generated by computing the eigenvalues of the second derivatives of Gaussian filtered image at multiple scales. Then, the second order local entropy thresholding is applied to segment the vessel map. Lastly, a rule-based decision step, which measures the geometric shape difference between vessels and lesions is applied to reduce false positives. The algorithm is evaluated on the low-resolution DRIVE and STARE databases and the publicly available high-resolution image database from Friedrich-Alexander University Erlangen-Nuremberg, Germany). The proposed method achieved comparable performance to state of the art unsupervised vessel segmentation methods with a competitive faster speed on the DRIVE and STARE databases. For the high resolution fundus image database, the proposed algorithm outperforms an existing approach both on performance and speed. The efficiency and robustness make the blood vessel segmentation method described here suitable for broad application in automated analysis of retinal images.

  10. In- and ex-vessel flooding as part of the severe accident strategy in the KERENA reactor

    International Nuclear Information System (INIS)

    Levi, P.; Fischer, M.

    2011-01-01

    Currently, AREVA NP is finalizing the basic design of the KERENA reactor, an advanced boiling water reactor with a net electric output of about 1250 MWe. The safety concept in the KERENA reactor is founded on reliable active and passive systems for water supply and heat removal. The passive systems are based on simple physics and do not require operator action. Therefore, a severe accident (SA) with core damage, caused by the subsequent and multiple failures of the safety systems, has an extremely low probability. Despite this, the KERENA design is intended to involve measures that can limit and stop the progression of the severe accident which further reduces the frequency and extent of radioactive releases into the environment. These additional measures include in-vessel and ex-vessel flooding. Flooding is intended to remove the heat from the core or from the reactor pressure vessel (RPV) and transfer it into the containment. There the heat is removed by the active RHR (residual heat removal) system or by the passive CCCs (containment cooling condensers). Both flooding measures are passive and actuated independent of each other by different signals. The study shows that the in-vessel flooding is capable of arresting the core melt progression before a large molten pool can develop. In the unlikely event that the passive in-vessel flooding cannot be actuated or fails, the core will melt and relocate into the lower head of the RPV. In this case, as a further line of defense, decay heat removal can be achieved through the RPV wall into the water in the cavity. In order to assess whether the ex-vessel cooling can ensure RPV wall integrity a dedicated thermodynamics code has been developed which considers heat transfer from the molten corium pool into the RPV wall and the resulting wall ablation. As an input for the code the stratification behavior of the oxidic and metallic phase of the molten pool is examined. In the case of a light metallic phase on top, high heat

  11. Ultrasonically enhanced fractionation of milk fat in a litre-scale prototype vessel.

    Science.gov (United States)

    Leong, Thomas; Johansson, Linda; Mawson, Raymond; McArthur, Sally L; Manasseh, Richard; Juliano, Pablo

    2016-01-01

    The ultrasonic fractionation of milk fat in whole milk to fractions with distinct particle size distributions was demonstrated using a stage-based ultrasound-enhanced gravity separation protocol. Firstly, a single stage ultrasound gravity separation was characterised after various sonication durations (5-20 min) with a mass balance, where defined volume partitions were removed across the height of the separation vessel to determine the fat content and size distribution of fat droplets. Subsequent trials using ultrasound-enhanced gravity separation were carried out in three consecutive stages. Each stage consisted of 5 min sonication, with single and dual transducer configurations at 1 MHz and 2 MHz, followed by aliquot collection for particle size characterisation of the formed layers located at the bottom and top of the vessel. After each sonication stage, gentle removal of the separated fat layer located at the top was performed. Results indicated that ultrasound promoted the formation of a gradient of vertically increasing fat concentration and particle size across the height of the separation vessel, which became more pronounced with extended sonication time. Ultrasound-enhanced fractionation provided fat enriched fractions located at the top of the vessel of up to 13 ± 1% (w/v) with larger globules present in the particle size distributions. In contrast, semi-skim milk fractions located at the bottom of the vessel as low as 1.2 ± 0.01% (w/v) could be produced, containing proportionally smaller sized fat globules. Particle size differentiation was enhanced at higher ultrasound energy input (up to 347 W/L). In particular, dual transducer after three-stage operation at maximum energy input provided highest mean particle size differentiation with up to 0.9 μm reduction in the semi-skim fractions. Higher frequency ultrasound at 2 MHz was more effective in manipulating smaller sized fat globules retained in the later stages of skimming than 1 MHz. While 2 MHz

  12. Prestressed concrete vessels suitable for helium high temperature reactors

    International Nuclear Information System (INIS)

    Lockett, G.E.; Kinkead, A.N.

    1967-02-01

    In considering prestressed concrete vessels for use with helium cooled high temperature reactors, a number of new problems arise and projected designs involve new approaches and new solutions. These reactors, having high coolant outlet temperature from the core and relatively high power densities, can be built into compact designs which permit usefully high working pressures. Consequently, steam generators and circulating units tend to be small. Although circuit activity can be kept quite low with coated particle fuels, designs which involve entry for subsequent repair are not favoured, and coupled with the preferred aim of using fully shop fabricated units within the designs with removable steam generators which involve no tube welding inside the vessel. A particular solution uses a number of slim cylindrical assemblies housed in the wall of the pressure vessel and this vessel design concept is presented. The use of helium requires very high sealing standards and one of the important requirements is a vessel design which permits leak testing during construction, so that a repair seal can be made to any faulty part in a liner seam. Very good demountable joint seals can be made without particular difficulty and Dragon experience is used to provide solutions which are suitable for prestressed concrete vessel penetrations. The concept layout is given of a vessel meeting these requirements; the basis of design is outlined and special features of importance discussed. (author)

  13. Multimodal imaging of vascular network and blood microcirculation by optical diagnostic techniques

    International Nuclear Information System (INIS)

    Kuznetsov, Yu L; Kalchenko, V V; Meglinski, I V

    2011-01-01

    We present a multimodal optical diagnostic approach for simultaneous non-invasive in vivo imaging of blood and lymphatic microvessels, utilising a combined use of fluorescence intravital microscopy and a method of dynamic light scattering. This approach makes it possible to renounce the use of fluorescent markers for visualisation of blood vessels and, therefore, significantly (tenfold) reduce the toxicity of the technique and minimise side effects caused by the use of contrast fluorescent markers. We demonstrate that along with the ability to obtain images of lymph and blood microvessels with a high spatial resolution, current multimodal approach allows one to observe in real time permeability of blood vessels. This technique appears to be promising in physiology studies of blood vessels, and especially in the study of peripheral cardiovascular system in vivo. (optical technologies in biophysics and medicine)

  14. Title: variations and sensitivities of some blood pressure monitors ...

    African Journals Online (AJOL)

    Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels. Accuracy in blood pressure meters is of essence to health, especially in blood pressure monitoring and treatment. The aim of this research was to compare the readings and the sensitivities of some blood pressure monitors in use ...

  15. ITER in-vessel system design and performance

    International Nuclear Information System (INIS)

    Parker, R.R.

    1999-01-01

    This paper reviews the design and performance of the in-vessel components of ITER as developed for the EDA Final Design Report (FDR). The double-wall vessel is the first confinement boundary and is designed to maintain its integrity under all normal and off-normal conditions, e.g., the most intense VDE's and seismic events. The shielding blanket consists of modules connected to a toroidal backplate by flexible connectors which allow differential displacements due to temperature differences. Breeding blanket modules replace the shield modules for the Enhanced Performance Phase. The divertor is based on a cassette structure which is convenient for remote installation and removal. High heat flux (HHF) components are mechanically attached and can be removed and replaced in the hot cell. Operation of the divertor is based on achieving partially detached plasma conditions along and near the separatrix. Nominal heat loads of 5-10 MW/m 2 are expected and these are accommodated by HHF technology developed during the EDA. Disruptions and VDE's can lead to melting of the first wall armour but no damage to the underlying structure. Stresses in the main structural components remain within allowables for all postulated disruption and seismic events. (author)

  16. ITER in-vessel system design and performance

    International Nuclear Information System (INIS)

    Parker, R.R.

    2001-01-01

    This paper reviews the design and performance of the in-vessel components of ITER as developed for the EDA Final Design Report (FDR). The double-wall vessel is the first confinement boundary and is designed to maintain its integrity under all normal and off-normal conditions, e.g., the most intense VDE's and seismic events. The shielding blanket consists of modules connected to a toroidal backplate by flexible connectors which allow differential displacements due to temperature differences. Breeding blanket modules replace the shield modules for the Enhanced Performance Phase. The divertor is based on a cassette structure which is convenient for remote installation and removal. High heat flux (HHF) components are mechanically attached and can be removed and replaced in the hot cell. Operation of the divertor is based on achieving partially detached plasma conditions along and near the separatrix. Nominal heat loads of 5-10 MW/m 2 are expected and these are accommodated by HHF technology developed during the EDA. Disruptions and VDE's can lead to melting of the first wall armour but no damage to the underlying structure. Stresses in the main structural components remain within allowables for all postulated disruption and seismic events. (author)

  17. Evaluation of HFIR vessel surveillance data and hydro-test conditions

    International Nuclear Information System (INIS)

    Cheverton, R.D.; Nanstad, R.K.

    1994-01-01

    Surveillance specimens for the High Flux Isotope Reactor (HFIR) pressure vessel were removed and tested during 1993, after the vessel had accumulated 701,469 MWd of operation. The data agree well with HFIR surveillance data obtained in previous years. In conjunction with this effort, the vessel hydro-test conditions were reevaluated and found to be more than adequate. In view of this result, and because there are economic incentives for reducing the frequency of hydro testing, an analysis was performed to determine the minimum permissible frequency. The value obtained is substantially less than that presently specified. It was also determined that a somewhat lower cooling-tower-basin temperature is acceptable (improves operational flexibility). In 1986, after ∼20 years of reactor operation, it was discovered that the vessel embrittlement rate was substantially greater than expected. Possible reasons for the accelerated rate are reviewed in this report

  18. 40 CFR 229.3 - Transportation and disposal of vessels.

    Science.gov (United States)

    2010-07-01

    ... procedures; (iv) Information on the potential effect of the vessel disposal on the marine environment; and (v... practicable all materials which may degrade the marine environment, including without limitation (i) emptying... and tanks are essentially free of petroleum, and (ii) removing from the hulls other pollutants and all...

  19. System for removing contaminants from plastic resin

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2010-11-23

    A resin recycling system that produces essentially contaminant-free synthetic resin material in an environmentally safe and economical manner. The system includes receiving the resin in container form. A grinder grinds the containers into resin particles. The particles are exposed to a solvent in one or more solvent wash vessels, the solvent contacting the resin particles and substantially removing contaminants on the resin particles. A separator is used to separate the resin particles and the solvent. The resin particles are then placed in solvent removing element where they are exposed to a solvent removing agent which removes any residual solvent remaining on the resin particles after separation.

  20. Post-accident fuel relocation and heat removal in the LMFBR

    International Nuclear Information System (INIS)

    Kazimi, M.S.; Tsai, S.S.; Gasser, R.D.

    1976-08-01

    Assessment of the dynamics of post-accident fuel relocation and heat removal is an important aspect of the evaluation of the consequences of a hypothetical accident in an LMFBR. Such an assessment is of particular importance in the evaluation of the post-accident radiological doses around the reactor site. In the present evaluation particular attention is given to the design features of the Clinch River Breeder Reactor Plant (CRBR). Fuel relocation and heat removal, assuming certain conditions have resulted in core disruption, are discussed. The discussion of events and phenomena involved in the relocation processes is centered around the resulting patterns of heat source distribution. The factors influencing fuel relocation and distribution in the inlet and outlet plena of the reactor vessel are discussed. The current technology of in-vessel heat removal is applied to the design of the CRBR reactor. Both fuel debris cooling limits and overall coolant flow in the reactor under natural convection conditions are explored. Some of the uncertainties in ex-vessel fuel behavior are addressed. In particular, the effect of melting the cavity bed on the rate of growth of a molten fuel pool is investigated

  1. Visual function and retinal vessel diameters during hyperthermia in man

    DEFF Research Database (Denmark)

    Jensen, Bettina Hagström; Bram, Thue; Kappelgaard, Per

    2017-01-01

    .01), a 10.6-mmHg mean reduction in diastolic blood pressure (p vein...... laser ophthalmoscopy was used to measure retinal trunk vessel diameters. Assessment was made at baseline, during hyperthermia and after cooling. RESULTS: The induction of a mean increase in core body temperature of 1.02°C was associated with a 7.15-mmHg mean reduction in systolic blood pressure (p

  2. TMI-2 reactor vessel plenum final lift

    International Nuclear Information System (INIS)

    Wilson, D.C.

    1986-01-01

    Removal of the plenum assembly from the TMI-2 reactor vessel was necessary to gain access to the core region for defueling. The plenum was lifted from the reactor vessel by the polar crane using three specially designed pendant assemblies. It was then transferred in air to the flooded deep end of the refueling canal and lowered onto a storage stand where it will remain throughout the defueling effort. The lift and transfer were successfully accomplished on May 15, 1985 in just under three hours by a lift team located in a shielded area within the reactor building. The success of the program is attributed to extensive mockup and training activities plus thorough preparations to address potential problems. 54 refs

  3. Safety studies on heat transport and afterheat removal for GCR accident conditions

    International Nuclear Information System (INIS)

    Hishida, Makoto

    1996-01-01

    The IAEA coordinated an international research program on 'Heat Transport and Afterheat Removal for GCRs under Accident Conditions (CRP-3)'. America, China, France, Germany, Japan, Netherlands and Russia participate the program. Final goal of the program is to show clearly to the world one of the most important salient features of the HTGR, that is the HTGR reactor can be cooled down by passive measures without causing any damage to the nuclear reactor system even in accidental conditions, and to make clear the boundaries (or restrictions) for the passive cooling regime. The first 5 year term of the coordinate program started in 1993 and established a goal to improve common knowledge for decay heat removal and to improve our tools, like computer codes and analytical models for the prediction of the performance of decay heat removal system. We are now performing benchmark problems for these purposes. The present efforts are concentrated on the benchmark for the passive heat removal performance outside the reactor vessel, partly because we have two different type of the HTGR in the world, the pebble bed type and the block type reactor. They have quite different heat dissipation behavior inside the reactor vessel. However, they have quite similar residual heat removal process outside the reactor vessel. For the first step of the international cooperation, we selected the common problem. After finishing the present benchmark we are planning to proceed to tackle the inside heat removal problem. (J.P.N.)

  4. Laser speckle contrast imaging of skin blood perfusion responses induced by laser coagulation

    Energy Technology Data Exchange (ETDEWEB)

    Ogami, M; Kulkarni, R; Wang, H; Reif, R; Wang, R K [University of Washington, Department of Bioengineering, Seattle, Washington 98195 (United States)

    2014-08-31

    We report application of laser speckle contrast imaging (LSCI), i.e., a fast imaging technique utilising backscattered light to distinguish such moving objects as red blood cells from such stationary objects as surrounding tissue, to localise skin injury. This imaging technique provides detailed information about the acute perfusion response after a blood vessel is occluded. In this study, a mouse ear model is used and pulsed laser coagulation serves as the method of occlusion. We have found that the downstream blood vessels lacked blood flow due to occlusion at the target site immediately after injury. Relative flow changes in nearby collaterals and anastomotic vessels have been approximated based on differences in intensity in the nearby collaterals and anastomoses. We have also estimated the density of the affected downstream vessels. Laser speckle contrast imaging is shown to be used for highresolution and fast-speed imaging for the skin microvasculature. It also allows direct visualisation of the blood perfusion response to injury, which may provide novel insights to the field of cutaneous wound healing. (laser biophotonics)

  5. Laser speckle contrast imaging of skin blood perfusion responses induced by laser coagulation

    Science.gov (United States)

    Ogami, M.; Kulkarni, R.; Wang, H.; Reif, R.; Wang, R. K.

    2014-08-01

    We report application of laser speckle contrast imaging (LSCI), i.e., a fast imaging technique utilising backscattered light to distinguish such moving objects as red blood cells from such stationary objects as surrounding tissue, to localise skin injury. This imaging technique provides detailed information about the acute perfusion response after a blood vessel is occluded. In this study, a mouse ear model is used and pulsed laser coagulation serves as the method of occlusion. We have found that the downstream blood vessels lacked blood flow due to occlusion at the target site immediately after injury. Relative flow changes in nearby collaterals and anastomotic vessels have been approximated based on differences in intensity in the nearby collaterals and anastomoses. We have also estimated the density of the affected downstream vessels. Laser speckle contrast imaging is shown to be used for highresolution and fast-speed imaging for the skin microvasculature. It also allows direct visualisation of the blood perfusion response to injury, which may provide novel insights to the field of cutaneous wound healing.

  6. Design study on steam generator integration into the VVER reactor pressure vessel

    International Nuclear Information System (INIS)

    Hort, J.; Matal, O.

    2004-01-01

    The primary circuit of VVER (PWR) units is arranged into loops where the heat generated by the reactor is removed by means of main circulating pumps, loop pipelines and steam generators, all located outside the reactor pressure vessel. If the primary circuit and reactor core were integrated into one pressure vessel, as proposed, e.g., within the IRIS project (WEC), a LOCA situation would be limited by the reactor pressure vessel integrity only. The aim of this design study regarding the integration of the steam generator into the reactor pressure vessel was to identify the feasibility limits and some issues. Fuel elements and the reactor pressure vessel as used in the Temelin NPP were considered for the analysis. From among the variants analyzed, the variant with steam generators located above the core and vertically oriented circulating pumps at the RPV lower bottom seems to be very promising for future applications

  7. Effects of the tumor-vasculature-disrupting agent verubulin and two heteroaryl analogues on cancer cells, endothelial cells, and blood vessels.

    Science.gov (United States)

    Mahal, Katharina; Resch, Marcus; Ficner, Ralf; Schobert, Rainer; Biersack, Bernhard; Mueller, Thomas

    2014-04-01

    Two analogues of the discontinued tumor vascular-disrupting agent verubulin (Azixa®, MPC-6827, 1) featuring benzo-1,4-dioxan-6-yl (compound 5 a) and N-methylindol-5-yl (compound 10) residues instead of the para-anisyl group on the 4-(methylamino)-2-methylquinazoline pharmacophore, were prepared and found to exceed the antitumor efficacy of the lead compound. They were antiproliferative with single-digit nanomolar IC50 values against a panel of nine tumor cell lines, while not affecting nonmalignant fibroblasts. Indole 10 surpassed verubulin in seven tumor cell lines including colon, breast, ovarian, and germ cell cancer cell lines. In line with docking studies indicating that compound 10 may bind the colchicine binding site of tubulin more tightly (Ebind =-9.8 kcal mol(-1) ) than verubulin (Ebind =-8.3 kcal mol(-1) ), 10 suppressed the formation of vessel-like tubes in endothelial cells and destroyed the blood vessels in the chorioallantoic membrane of fertilized chicken eggs at nanomolar concentrations. When applied to nude mice bearing a highly vascularized 1411HP germ cell xenograft tumor, compound 10 displayed pronounced vascular-disrupting effects that led to hemorrhages and extensive central necrosis in the tumor. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Photoacoustic discrimination of viable and thermally coagulated blood using a two-wavelength method for burn injury monitoring

    International Nuclear Information System (INIS)

    Talbert, Robert J; Holan, Scott H; Viator, John A

    2007-01-01

    Discriminating viable from thermally coagulated blood in a burn wound can be used to profile burn depth, thus aiding the removal of necrotic tissue. In this study, we used a two-wavelength photoacoustic imaging method to discriminate coagulated and non-coagulated blood in a dermal burn phantom. Differences in the optical absorption spectra of coagulated and non-coagulated blood produce different values of the ratio of peak photoacoustic amplitude at 543 and 633 nm. The absorption values obtained from spectroscopic measurements indicate that the ratio of photoacoustic pressure for 543 and 633 nm for non-coagulated blood was 15.7:1 and 1.6:1 for coagulated blood. Using planar blood layers, we found the photoacoustic ratios to be 13.5:1 and 1.6:1, respectively. Using the differences in the ratios of coagulated and non-coagulated blood, we propose a scheme using statistical classification analysis to identify the different blood samples. Based upon these distinctly different ratios, we identified the planar blood samples with an error rate of 0%. Using a burn phantom with cylindrical vessels containing coagulated and non-coagulated blood, we achieved an error rate of 11.4%. These results have shown that photoacoustic imaging could prove to be a valuable tool in the diagnosis of burns

  9. Inversion prepared coronary MR angiography: direct visualization of coronary blood flow

    International Nuclear Information System (INIS)

    Katoh, M.; Spuentrup, E.; Buecker, A.; Guenther, R.W.; Stuber, M.; Manning, W.J.; Botnar, R.M.

    2005-01-01

    Purpose: visualization of coronary blood flow by means of a slice-selective inversion pre-pulse in concert with bright-blood coronary MRA. Materials and methods: coronary magnetic resonance angiography (MRA) of the right coronary artery (RCA) was performed in eight healthy adult subjects on a 1.5 Tesla MR system (Gyroscan ACS-NT, Philips Medical Systems, Best, NL) using a free-breathing navigator-gated and cardiac-triggered 3D steady-state free-precession (SSFP) sequence with radial k-space sampling. Imaging was performed with and without a slice-selective inversion pre-pulse, which was positioned along the main axis of the coronary artery but perpendicular to the imaging volume. Objective image quality parameters such as SNR, CNR, maximal visible vessel length, and vessel border definition were analyzed. Results: in contrast to conventional bright-blood 3D coronary MRA, the selective inversion pre-pulse provided a direct measure of coronary blood flow. In addition, CNR between the RCA and right ventricular blood pool was increased and the vessels had a tendency towards better delineation. Blood SNR and CNR between right coronary blood and epicardial fat were comparable in both sequences. (orig.)

  10. Preparation of the Shippingport reactor pressure vessel shipping package

    International Nuclear Information System (INIS)

    Yannitell, D.M.

    1988-01-01

    Shippingport Station Decommissioning Project is the removal and shipment the Reactor Pressure Vessel (PRV) and its associated Neutron Shield Tank (NST) to the government owned Hanford Reservation in Richland, Washington. Engineering studies considered the alternatives for removal and shipment of the RPV/NST. These included segmentation for subsequent truck shipments, and one-piece removal with barge or rail shipment. Although the analysis indicated that current technology could be utilized to accomplish either alternative, one-piece removal of the RPV was selected as the safest, most cost effective method. When compared to segmentation, it was estimated that one-piece removal would reduce the duration of the Project by 1 year, reduce cost by $4 M, and result in a savings of radiation exposure of 150 man-Rem. Rail transportation of an integral RPV/NST package is not feasible due to the physical size of the package. 5 refs., 1 fig

  11. Radiation embrittlement of Spanish nuclear reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Bros, J.; Ballesteros, A.; Lopez, A.

    1993-01-01

    Commercial pressurized water reactor (PWR) and boiling water reactor (BWR) nuclear power plants contain a series of pressure vessel steel surveillance capsules as the principal means of monitoring radiation effects on the pressure vessel. Changes in fracture toughness are more severe in surveillance capsules than in reactor vessel materials because of their proximity of the reactor core. Therefore, it is possible to predict changes in fracture toughness of the reactor vessel materials. This paper describes the status of the reactor vessel surveillance program relating to Spanish nuclear power plants. To date, twelve capsules have been removed and analyzed from seven of the nine Spanish reactors in operation. The results obtained from the analysis of these capsules are compared with the predictions of the Nuclear Regulatory Commission (NRC) Regulatory Guide 1.99, Rev. 2, by means of measured and expected increase of the nil-ductility transition reference temperature (RT NDT ). The comparison is made considering the different variables normally included in the studies of radiation response of reactor pressure vessel materials, such as copper content of steel, level of neutron fluence above 1 MeV, base metal or weld metal, and so forth. The surveillance data have been used for determining the adjusted reference temperatures and upper shelf energies at any time. The results have shown that the seven pressure vessels are in excellent condition to continue operating with safety against brittle fracture beyond the design life, without the need to recuperate the degraded properties of the materials by annealing of the vessel

  12. Development of a dynamic in vitro model of a stented blood vessel to evaluate the effects of stent strut material selection and surface coating on smooth muscle cell response

    Science.gov (United States)

    Winn, Bradley Huegh

    Cardiovascular disease is the leading cause of mortality in The United States and Europe, accounting for approximately half of all deaths. The most common form of cardiovascular disease is atherosclerosis, which is characterized by the formation of fatty atheromatous plaques that can grow to occlude the vessel lumen, thus causing ischemia distal to the occlusion. This is commonly treated using balloon angioplasty, which is usually done in conjunction with the deployment of a stent. Stent deployment helps hold the vessel open following the local injury caused by balloon inflation and prevents elastic recoil and subsequent negative remodeling. Stenting has been shown to significantly reduce restenosis rates from approximately 20-50% without a stent to about 10-30% with stent deployment. However, restenosis still remains the main cause of long-term stent failure. In basic terms, a balloon angioplasty procedure is a forceful displacement of an atherosclerotic lesion serving to widen the vessel lumen to increase blood flow. This procedure causes stretching of the vessel wall, tears in the atherosclerotic plaques, and general damage to the vessel in turn signaling a complex cascade of thrombosis, inflammation, intimal thickening, and vascular remodeling. Stent deployment also further complicates the immunological response by triggering a foreign body response from the implantation of a biomaterial into the body. When performing an angioplasty procedure, particularly in conjunction with stent deployment, a certain degree of vascular injury is inevitable. However, the initial injury can be further complicated by the body's local reaction to the implanted biomaterial, the severity of which can ultimately dictate the degree of restenosis and subsequently affect procedural success. The proliferative response of VSMCs to the various afore mentioned stimuli results in the formation of often copious amounts of neointimal tissue, generally known as intimal hyperplasia. The

  13. [Intervention of chronic hepatitis B liver fibrosis patients in different stages by syndrome typing and different activating blood removing stasis methods: a clinical study].

    Science.gov (United States)

    Liu, Shi-yi; Zhang, Yin-qiang; Liu, Yan-ling; Guo, Peng; Zhou, Chun-mei

    2013-11-01

    To observe the clinical efficacy of treating chronic hepatitis B liver fibrosis (CHBLF) in different stages by syndrome typing and different activating blood removing stasis methods (ABRSM). Totally 100 CHBLF patients of vital qi deficiency blood stasis syndrome (VQDBSS) treated at the Department of Liver Diseases, Xiyuan Hospital, China Academy of Chinese Medical Sciences from July 2008 to December 2011, were randomly assigned to the treatment group and the control group, 50 in each group. Those in the treatment group were treated by self-formulated decoctions for activating blood nourishing blood (ABNB), activating blood removing stasis (ABRS), and activating blood softening hard mass (ABSHM) according to their stages of disease conditions (mild, moderate, and severe). Those in the control group were treated with Compound Biejia Ruangan Tablet (CBRT). Integrals of Chinese medical syndromes, liver functions [mainly including alanine aminotransferase (ALT), albumin/globulin (A/ G)], ultrasonographic examinations of liver (mainly including echoes of liver, width of spleens, width of portal vein), four indicators of serum hepatic fibrosis [including serum hyaluronic acid (HA), laminin (LN), type IV collagen (IV-C), type III collagen peptide (P-III-P)] were statistically analyzed. The therapeutic course was 6 months for all. Compared with before treatment in the same group, the integrals of Chinese medical syndromes both decreased after treatment in the two groups (P serum biochemical indicators.

  14. Tumor Vessel Compression Hinders Perfusion of Ultrasonographic Contrast Agents

    Directory of Open Access Journals (Sweden)

    Mirco Galiè

    2005-05-01

    Full Text Available Contrast-enhanced ultrasound (CEUS is an advanced approach to in vivo assessment of tumor vascularity and is being increasingly adopted in clinical oncology. It is based on 1- to 10 μm-sized gas microbubbles, which can cross the capillary beds of the lungs and are effective echo enhancers. It is known that high cell density, high transendothelial fluid exchange, and poorly functioning lymphatic circulation all provoke solid stress, which compresses vessels and drastically reduces tumor blood flow. Given their size, we supposed that the perfusion of microbubbles is affected by anatomic features of tumor vessels more than are contrast agents traditionally used in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI. Here, we compared dynamic information obtained from CEUS and DCE-MRI on two experimental tumor models exhibiting notable differences in vessel anatomy. We found that tumors with small, flattened vessels show a much higher resistance to microbubble perfusion than to MRI contrast agents, and appear scarcely vascularized at CEUS examination, despite vessel volume adequate for normal function. Thus, whereas CEUS alone could induce incorrect diagnosis when tumors have small or collapsed vessels, integrated analysis using CEUS and DCE-MRI allows in vivo identification of tumors with a vascular profile frequently associated with malignant phenotypes.

  15. [Anatomical study and clinical application of a leg flap pedicle-included with cutaneous nerve and its concomitant vessels].

    Science.gov (United States)

    Liu, B; Hao, X; Goan, M

    2000-05-01

    To investigate the blood supply patterns and the clinical liability of a leg flap pedicle-included with cutaneous nerve and its concomitant vessels. Fresh cadaver legs with thirty-two in infants and two in adults were anatomically examined after the intravenous injection of the red Chlorinated Poly Vingl Choride (CPVC). Five patients with the soft tissue defects were selected for the treatment with the flap pedicle-included with the cutaneous nerve and its concomitant vessels. Four main cutaneous nerves were found in the leg after they perforated the deep fascia out. They were companioned with their concomitant vessels with different blood-supply pateeerns, which the upper part of the leg was in an axial pattern and the lower part was in a "chain-type anastomosing" pattern. Following the above-mentioned findings, five cases were successfully treated with this led flap. The leg flap should be designed along the cutaneous nerve and its concomitant vessels. When the flap is applied in the area of blood supply with "chain-type anastomosing" pattern, the deep fascia should also be included in the flap.

  16. Effect on osmotic fragility of red blood cells of whole blood submitted ...

    African Journals Online (AJOL)

    Administrator

    2011-10-19

    Oct 19, 2011 ... hertz (Hz)], vibration magnitude measured as amplitude. [displacement of the ... the work in the OP and the body position/posture on the platform. ... place through the pressure applied from outside on blood vessels when ...

  17. Fetal blood drawing.

    Science.gov (United States)

    Hobbins, J C; Mahoney, M J

    1975-07-19

    A small sample of fetal blood suitable for studies of haemoglobin synthesis was obtained from a placental vessel under endoscopic visualisation in 23 of 26 patients in whom the procedure was attempted prior to second-trimester abortion. Fetal blood loss, calculated in 23 cases, was between 0-2 ml. and 2-5 ml., and fetal blood-volume depletion varied from 0-5% to 15%. No short-term ill-effects were demonstrated in mother or fetus in any of 16 patients in whom the injection of aborti-facient was postponed for between 16 and 24 hours after the procedure.

  18. Platform image processing to study the structural properties of retinal vessel

    Directory of Open Access Journals (Sweden)

    Miguel Ángel MERCHÁN

    2013-05-01

    Full Text Available This paper presents a technological platform specialized in assessing retinal vessel caliber and describing the relationship of the results obtained to cardiovascular risk. Retinal circulation is an area of active research by numerous groups, and there is general experimental agreement on the analysis of the patterns of the retinal blood vessels in the normal human retina. The development of automated tools designed to improve performance and decrease interobserver variability, therefore, appears necessary. 

  19. Human and nonhuman primate meninges harbor lymphatic vessels that can be visualized noninvasively by MRI.

    Science.gov (United States)

    Absinta, Martina; Ha, Seung-Kwon; Nair, Govind; Sati, Pascal; Luciano, Nicholas J; Palisoc, Maryknoll; Louveau, Antoine; Zaghloul, Kareem A; Pittaluga, Stefania; Kipnis, Jonathan; Reich, Daniel S

    2017-10-03

    Here, we report the existence of meningeal lymphatic vessels in human and nonhuman primates (common marmoset monkeys) and the feasibility of noninvasively imaging and mapping them in vivo with high-resolution, clinical MRI. On T2-FLAIR and T1-weighted black-blood imaging, lymphatic vessels enhance with gadobutrol, a gadolinium-based contrast agent with high propensity to extravasate across a permeable capillary endothelial barrier, but not with gadofosveset, a blood-pool contrast agent. The topography of these vessels, running alongside dural venous sinuses, recapitulates the meningeal lymphatic system of rodents. In primates, meningeal lymphatics display a typical panel of lymphatic endothelial markers by immunohistochemistry. This discovery holds promise for better understanding the normal physiology of lymphatic drainage from the central nervous system and potential aberrations in neurological diseases.

  20. Correlation between expressions of hypoxia -inducible factor (HIF-1α, blood vessels density, cell proliferation, and apoptosis intensity in canine fibromas and fibrosarcomas

    Directory of Open Access Journals (Sweden)

    Madej Janusz A.

    2014-03-01

    Full Text Available The study aimed to demonstrate the expression of hypoxia-inducible factor (HIF-1α in soft tissue mesenchymal tumours (fibroma and fibrosarcoma in dogs. An attempt was made to correlate the obtained results with density of blood vessels (expression of von Willebrand Factor, vWF, expression of Ki-67 proliferation antigen, and with intensity of apoptosis in studied tumours. The study was performed on paraffin sections of 15 fibromas and 40 fibrosarcomas sampled from 55 female dogs aged 6 to 16 years. Immunohistochemical staining against HIF-1α, vWF, and Ki-67 was performed. Apoptosis was detected with the use of TUNEL reaction. A significantly higher HIF-1α expression was noted in fibrosarcomas in comparison to fibromas (P < 0.0001. HIF-1α expression in fibromas manifested strong positive correlation with tumour vascularity (r = 0.67, P = 0.007. Moreover, HIF-1α expression in fibrosarcomas manifested a moderate positive correlation with tumour malignancy grade (r = 0.44, P = 0.004, tumour vascularity (r = 0.52, P < 0.001, Ki-67 antigen expression (r = 0.42; P = 0.007, and TUNELpositive cells (r = 0.37, P = 0.017. Expression of HIF-1α was detected in 86.7% of fibroma type tumours and in 100% of fibrosarcomas. In all studied tumours expression of HIF-1α manifested positive correlation with the density of blood vessels, and in fibrosarcomas it correlated also with malignancy grade, intensity of Ki-67 expression, and with intensity of apoptosis in tumour cells.

  1. High-Temperature Gas-cooled Reactor steam-cycle/cogeneration lead plant reactor vessel: system design description

    International Nuclear Information System (INIS)

    1983-01-01

    The Reactor Vessel System contains the primary coolant inventory within a gas-tight pressure boundary, and provides the necessary flow paths and overpressure protection for this pressure boundary. The Reactor Vessel System also houses the components of the Reactor System, the Heat Transport System, and the Auxiliary Heat Removal System. The scope of the Reactor Vessel System includes the prestressed concrete reactor vessel (PCRV) structure with its reinforcing steel and prestressing components; liners, penetrations, closures, and cooling water tubes attached to the concrete side of the liner; the thermal barrier (insulation) on the primary coolant side of the liner; instrumentation for structural monitoring; and a pressure relief system. Specifications are presented

  2. Organically modified clay removes oil from water

    International Nuclear Information System (INIS)

    Alther, G.R.

    1995-01-01

    When bentonite or other clays and zeolite are modified with quaternary amines, they become organophilic. Such modified bentonites are used to remove mechanically emulsified oil and grease, and other sparingly soluble organics. Types of oil found in water can include fats, lubricants, cutting fluids, heavy hydrocarbons such as tars, grease, crude oil, diesel oils; and light hydrocarbons such as kerosene, jet fuel, and gasoline. If the organoclay is granulated, it is placed into a liquid phase carbon filter vessel to remove FOGs (Free Oil and Grease) and chlorinated hydrocarbons. In this application the clay is mixed with anthrazite to prevent early plugging of the filter by oil or grease droplets. In batch systems a powdered organoclay is employed. Organoclay removes mechanically emulsified oil and grease at 5--7 times the rate of activated carbon, or 50% of its dry weight. Oil and grease and other large sparingly soluble chlorinated hydrocarbons and NOMs (Natural Organic Matter) blind the pores of activated carbon (and ion-exchange resins), reducing its effectiveness significantly. It is therefore economically advantageous for the end user to prepolish the water before it enters carbon vessels. Operating costs can often be reduced by 50% or more

  3. Direct numerical simulation of cellular-scale blood flow in microvascular networks

    Science.gov (United States)

    Balogh, Peter; Bagchi, Prosenjit

    2017-11-01

    A direct numerical simulation method is developed to study cellular-scale blood flow in physiologically realistic microvascular networks that are constructed in silico following published in vivo images and data, and are comprised of bifurcating, merging, and winding vessels. The model resolves large deformation of individual red blood cells (RBC) flowing in such complex networks. The vascular walls and deformable interfaces of the RBCs are modeled using the immersed-boundary methods. Time-averaged hemodynamic quantities obtained from the simulations agree quite well with published in vivo data. Our simulations reveal that in several vessels the flow rates and pressure drops could be negatively correlated. The flow resistance and hematocrit are also found to be negatively correlated in some vessels. These observations suggest a deviation from the classical Poiseuille's law in such vessels. The cells are observed to frequently jam at vascular bifurcations resulting in reductions in hematocrit and flow rate in the daughter and mother vessels. We find that RBC jamming results in several orders of magnitude increase in hemodynamic resistance, and thus provides an additional mechanism of increased in vivo blood viscosity as compared to that determined in vitro. Funded by NSF CBET 1604308.

  4. Preliminary Performance Analysis Program Development for Safety System with Safeguard Vessel

    International Nuclear Information System (INIS)

    Kang, Han-Ok; Lee, Jun; Park, Cheon-Tae; Yoon, Ju-Hyeon; Park, Keun-Bae

    2007-01-01

    SMART is an advanced modular integral type pressurized water reactor for a seawater desalination and an electricity production. Major components of the reactor coolant system such as the pressurizer, Reactor Coolant Pump (RCP), and steam generators are located inside the reactor vessel. The SMART can fundamentally eliminate the possibility of large break loss of coolant accidents (LBLOCAs), improve the natural circulation capability, and better accommodate and thus enhance a resistance to a wide range of transients and accidents. The safety goals of the SMART are enhanced through highly reliable safety systems such as the passive residual heat removal system (PRHRS) and the safeguard vessel coupled with the passive safety injection feature. The safeguard vessel is a steel-made, leak-tight pressure vessel housing the RPV, SIT, and the associated valves and pipelines. A primary function of the safeguard vessel is to confine any radioactive release from the primary circuit within the vessel under DBAs related to loss of the integrity of the primary system. A preliminary performance analysis program for a safety system using the safeguard vessel is developed in this study. The developed program is composed of several subroutines for the reactor coolant system, passive safety injection system, safeguard vessel including the pressure suppression pool, and PRHRS. A small break loss of coolant accident at the upper part of a reactor is analyzed and the results are discussed

  5. Novel algorithm by low complexity filter on retinal vessel segmentation

    Science.gov (United States)

    Rostampour, Samad

    2011-10-01

    This article shows a new method to detect blood vessels in the retina by digital images. Retinal vessel segmentation is important for detection of side effect of diabetic disease, because diabetes can form new capillaries which are very brittle. The research has been done in two phases: preprocessing and processing. Preprocessing phase consists to apply a new filter that produces a suitable output. It shows vessels in dark color on white background and make a good difference between vessels and background. The complexity is very low and extra images are eliminated. The second phase is processing and used the method is called Bayesian. It is a built-in in supervision classification method. This method uses of mean and variance of intensity of pixels for calculate of probability. Finally Pixels of image are divided into two classes: vessels and background. Used images are related to the DRIVE database. After performing this operation, the calculation gives 95 percent of efficiency average. The method also was performed from an external sample DRIVE database which has retinopathy, and perfect result was obtained

  6. Effects of 532 nm pulsed-KTP laser parameters on vessel ablation in the avian chorioallantoic membrane: implications for vocal fold mucosa.

    Science.gov (United States)

    Broadhurst, Matthew S; Akst, Lee M; Burns, James A; Kobler, James B; Heaton, James T; Anderson, R Rox; Zeitels, Steven M

    2007-02-01

    Selective vascular ablation (photoangiolysis) using pulsed lasers that target hemoglobin is an effective treatment strategy for many vocal fold lesions. However, vessel rupture with extravasation of blood reduces selectivity for vessels, which is frequently observed with the 0.45-ms, 585-nm pulsed dye laser. Previous studies have shown that vessel rupture is the result of vaporization of blood, an event that varies with laser pulse width and pulse fluence (energy per unit area). Clinical observations using a 532-nm wavelength pulsed potassium-titanyl-phosphate (KTP) laser revealed less laser-induced hemorrhage than the pulsed dye laser. This study investigated settings for the pulsed KTP laser to achieve selective vessel destruction without rupture using the avian chorioallantoic membrane under conditions similar to flexible laryngoscopic delivery of the laser in clinical practice. The chick chorioallantoic membrane offers convenient access to many small blood vessels similar in size to those targeted in human vocal fold. Using a 532-nm pulsed KTP laser, pulse width, pulse energy, and working distance from the optical delivery fiber were varied to assess influence on the ability to achieve vessel coagulation without vessel wall rupture. Third-order vessels (n = 135) were irradiated: Energy (471-550 mJ), pulse width (10, 15, 30 ms), and fiber-to-tissue distance (1 mm, 3 mm) were varied systematically. Selective vessel destruction without vessel wall rupture was more often achieved by increasing pulse width, increasing the fiber-to-tissue distance, and decreasing energy. Vessel destruction without rupture was consistently achieved using 15- or 30-ms pulses with a fiber-to-tissue distance of 3 mm (pulse fluence of 13-16 J/cm). This study substantiates our clinical observation that a 532-nm pulsed KTP laser was effective for ablating microcirculation while minimizing vessel wall rupture and hemorrhage.

  7. ITER in-vessel system design and performance

    Science.gov (United States)

    Parker, R. R.

    2000-03-01

    The article reviews the design and performance of the in-vessel components of ITER as developed for the Engineering Design Activities (EDA) Final Design Report. The double walled vacuum vessel is the first confinement boundary and is designed to maintain its integrity under all normal and off-normal conditions, e.g. the most intense vertical displacement events (VDEs) and seismic events. The shielding blanket consists of modules connected to a toroidal backplate by flexible connectors which allow differential displacements due to temperature non-uniformities. Breeding blanket modules replace the shield modules for the Enhanced Performance Phase. The divertor concept is based on a cassette structure which is convenient for remote installation and removal. High heat flux (HHF) components are mechanically attached and can be removed and replaced in the hot cell. Operation of the divertor is based on achieving partially detached plasma conditions along and near the separatrix. Nominal heat loads of 5-10 MW/m2 are expected on the target. These are accommodated by HHF technology developed during the EDA. Disruptions and VDEs can lead to melting of the first wall armour but no damage to the underlying structure. Stresses in the main structural components remain within allowable ranges for all postulated disruption and seismic events.

  8. ITER in-vessel system design and performance

    International Nuclear Information System (INIS)

    Parker, R.R.

    2000-01-01

    The article reviews the design and performance of the in-vessel components of ITER as developed for the Engineering Design Activities (EDA) Final Design Report. The double walled vacuum vessel is the first confinement boundary and is designed to maintain its integrity under all normal and off-normal conditions, e.g. the most intense vertical displacement events (VDEs) and seismic events. The shielding blanket consists of modules connected to a toroidal backplate by flexible connectors which allow differential displacements due to temperature non-uniformities. Breeding blanket modules replace the shield modules for the Enhanced Performance Phase. The divertor concept is based on a cassette structure which is convenient for remote installation and removal. High heat flux (HHF) components are mechanically attached and can be removed and replaced in the hot cell. Operation of the divertor is based on achieving partially detached plasma conditions along and near the separatrix. Nominal heat loads of 5-10 MW/m 2 are expected on the target. These are accommodated by HHF technology developed during the EDA. Disruptions and VDEs can lead to melting of the first wall armour but no damage to the underlying structure. Stresses in the main structural components remain within allowable ranges for all postulated disruption and seismic events. (author)

  9. Modification of a Kowa RC-2 fundus camera for self-photography without the use of mydriatics. [for blood vessel monitoring during space flight

    Science.gov (United States)

    Philpott, D. E.; Harrison, G.; Turnbill, C.; Bailey, P. F.

    1979-01-01

    Research on retinal circulation during space flight required the development of a simple technique to provide self monitoring of blood vessel changes in the fundus without the use of mydriatics. A Kowa RC-2 fundus camera was modified for self-photography by the use of a bite plate for positioning and cross hairs for focusing the subject's retina relative to the film plane. Dilation of the pupils without the use of mydriatics was accomplished by dark-adaption of the subject. Pictures were obtained without pupil constriction by the use of a high speed strobe light. This method also has applications for clinical medicine.

  10. Obstacle detection method, obstacle removing method, device and production line for practicing the methods

    International Nuclear Information System (INIS)

    Yoneyama, Takao; Ishimatsu, Tsuneo; Komata, Hisashi; Suzuki, Keisaburo.

    1997-01-01

    The present invention provides techniques for detecting and removing obstacles, which can be applied to pipelines and vessels to be used in structures such as nuclear power structures and electric power generation facilities. Namely, when the pipelines or vessels are in any of the stages, namely, production, installation, before the use after installation and before the reuse after inspection, obstacles remaining in the pipelines and vessels are blown off by using a fluid jetting mechanism (air compressor). Elastic waves generated when the blown off obstacles abut against the pipelines and vessels are detected by using a sensor. As a result, the remaining obstacles can be detected during any one of the stages described above. The blowing is repeated till the absence of the obstacles is confirmed by elastic wave signals detected by the sensor. As a result, the remaining obstacles can be removed. (I.S.)

  11. Expression of nm23-H1 gene product in esophageal squamous cell carcinoma and its association with vessel invasion and survival

    International Nuclear Information System (INIS)

    Tomita, Masaki; Ayabe, Takanori; Matsuzaki, Yasunori; Edagawa, Masao; Maeda, Masayuki; Shimizu, Tetsuya; Hara, Masaki; Onitsuka, Toshio

    2001-01-01

    We assessed the nm23-H1 gene product expression and its relationship with lymphatic and blood vessel invasion in patients with esophageal squamous cell carcinoma. Formalin-fixed and paraffin-embedded tissue sections from 45 patients who were treated surgically were used in this study. Pathologists graded lymphatic and blood vessel invasion in each of the tissue samples. Expression of nm23-Hl gene product was determined using a specific monoclonal antibody. Expression of nm23-H1 gene product was present in 17 (37.8%) cases. We found an inverse correlation between nm23-H1 gene product expression and lymphatic vessel invasion, whereas no correlation between nm23-H1 gene product expression and blood vessel invasion. Overall survival rate was not different between nm23-H1 gene product positive and negative patients (p = 0.21). However, reduced expression of nm23-H1 gene product was associated with shorter overall survival in patients with involved lymph nodes (p < 0.05), but not in patients without involved lymph nodes (p = 0.87). In patients with esophageal squamous cell carcinoma, there appears to be an inverse relationship between nm23-H1 gene product expression and lymphatic vessel invasion. Furthermore, nm23-H1 gene product expression might be a prognostic marker in patients with involved lymph nodes. Our data does not demonstrate any correlation between nm23-H1 gene product expression and blood vessel invasion

  12. Flaw density examinations of a clad boiling water reactor pressure vessel segment

    International Nuclear Information System (INIS)

    Cook, K.V.; McClung, R.W.

    1986-01-01

    Flaw density is the greatest uncertainty involved in probabilistic analyses of reactor pressure vessel failure. As part of the Heavy-Section Steel Technology (HSST) Program, studies have been conducted to determine flaw density in a section of reactor pressure vessel cut from the Hope Creek Unit 2 vessel [nominally 0.7 by 3 m (2 by 10 ft)]. This section (removed from the scrapped vessel that was never in service) was evaluated nondestructively to determine the as-fabricated status. We had four primary objectives: (1) evaluate longitudinal and girth welds for flaws with manual ultrasonics, (2) evaluate the zone under the nominal 6.3-mm (0.25-in.) clad for cracking (again with manual ultrasonics), (3) evaluate the cladding for cracks with a high-sensitivity fluorescent penetrant method, and (4) determine the source of indications detected

  13. Electromechanical Model of Blood Flow in Vessels

    OpenAIRE

    Ivo Cap; Barbora Czippelova

    2008-01-01

    The present paper deals with some theoretical derivations connected with very efficient method of solution of hydrodynamic problems of blood flow in human cardiovascular system. The electromechanical analogy of liquid flow in a tube and electromagnetic wave propagating along an electric transmission line is discussed. We have derived a detailed circuit-like model of an elementary section of the elastic tube with viscose Newtonian liquid. The analogy harmonic current electrical cir...

  14. Segmentation of vessels cluttered with cells using a physics based model.

    Science.gov (United States)

    Schmugge, Stephen J; Keller, Steve; Nguyen, Nhat; Souvenir, Richard; Huynh, Toan; Clemens, Mark; Shin, Min C

    2008-01-01

    Segmentation of vessels in biomedical images is important as it can provide insight into analysis of vascular morphology, topology and is required for kinetic analysis of flow velocity and vessel permeability. Intravital microscopy is a powerful tool as it enables in vivo imaging of both vasculature and circulating cells. However, the analysis of vasculature in those images is difficult due to the presence of cells and their image gradient. In this paper, we provide a novel method of segmenting vessels with a high level of cell related clutter. A set of virtual point pairs ("vessel probes") are moved reacting to forces including Vessel Vector Flow (VVF) and Vessel Boundary Vector Flow (VBVF) forces. Incorporating the cell detection, the VVF force attracts the probes toward the vessel, while the VBVF force attracts the virtual points of the probes to localize the vessel boundary without being distracted by the image features of the cells. The vessel probes are moved according to Newtonian Physics reacting to the net of forces applied on them. We demonstrate the results on a set of five real in vivo images of liver vasculature cluttered by white blood cells. When compared against the ground truth prepared by the technician, the Root Mean Squared Error (RMSE) of segmentation with VVF and VBVF was 55% lower than the method without VVF and VBVF.

  15. Effect of transcutaneous electrical muscle stimulation and passive cycling movements on blood pressure and removal of urea and phosphate during hemodialysis.

    Science.gov (United States)

    Farese, Stefan; Budmiger, Raphael; Aregger, Fabienne; Bergmann, Ivo; Frey, Felix J; Uehlinger, Dominik E

    2008-10-01

    Intradialytic exercise has been described to improve blood pressure stability and dialysis efficacy. However, comorbid conditions in the dialysis population often preclude the widespread use of active intradialytic exercise. Therefore, we investigated the effect of intradialytic transcutaneous muscle stimulation (TEMS) and passive cycling movements (PCMs) on blood pressure and dialysis efficacy in patients. Prospective, controlled, randomized, crossover investigation. Ten patients were randomly allocated to TEMS, PCMs, or no intervention (NI) for 9 consecutive dialysis sessions. Participants were studied with NI, PCMs using a motor-driven ergometer, and bilateral TEMS of the leg musculature. Individual dialysis prescriptions were unchanged during the investigation. The effect of TEMS and PCMs on blood pressure and dialysis efficacy in patients was assessed. Mean blood pressure increased from 121/64 +/- 21/15 mm Hg with NI to 132/69 +/- 21/15 mm Hg (P TEMS. Urea and phosphate removal during dialysis were significantly (P TEMS (19.4 +/- 3.7 g/dialysis and 1,197 +/- 265 mg/dialysis) or PCMs (20.1 +/- 3.4 g/dialysis and 1,172 +/- 315 mg/dialysis) than with NI (15.1 +/- 3.9 g/dialysis and 895 +/- 202 mg/dialysis). Body weight, ultrafiltration, Kt/V, and increases in hemoglobin and albumin levels during dialysis did not differ among the NI, PCMs, and TEMS groups. The study design does not allow extension of the findings to prolonged treatment. Future studies during longer observation periods will have to prove the persistence of these acute findings. Both TEMS and PCMs deserve future investigations in dialysis patients because they increase intradialytic blood pressure and facilitate urea and phosphate removal when applied short term.

  16. Establishing the diffuse correlation spectroscopy signal relationship with blood flow.

    Science.gov (United States)

    Boas, David A; Sakadžić, Sava; Selb, Juliette; Farzam, Parisa; Franceschini, Maria Angela; Carp, Stefan A

    2016-07-01

    Diffuse correlation spectroscopy (DCS) measurements of blood flow rely on the sensitivity of the temporal autocorrelation function of diffusively scattered light to red blood cell (RBC) mean square displacement (MSD). For RBCs flowing with convective velocity [Formula: see text], the autocorrelation is expected to decay exponentially with [Formula: see text], where [Formula: see text] is the delay time. RBCs also experience shear-induced diffusion with a diffusion coefficient [Formula: see text] and an MSD of [Formula: see text]. Surprisingly, experimental data primarily reflect diffusive behavior. To provide quantitative estimates of the relative contributions of convective and diffusive movements, we performed Monte Carlo simulations of light scattering through tissue of varying vessel densities. We assumed laminar vessel flow profiles and accounted for shear-induced diffusion effects. In agreement with experimental data, we found that diffusive motion dominates the correlation decay for typical DCS measurement parameters. Furthermore, our model offers a quantitative relationship between the RBC diffusion coefficient and absolute tissue blood flow. We thus offer, for the first time, theoretical support for the empirically accepted ability of the DCS blood flow index ([Formula: see text]) to quantify tissue perfusion. We find [Formula: see text] to be linearly proportional to blood flow, but with a proportionality modulated by the hemoglobin concentration and the average blood vessel diameter.

  17. The blood-tendon barrier: identification and characterisation of a novel tissue barrier in tendon blood vessels

    Directory of Open Access Journals (Sweden)

    C Lehner

    2016-05-01

    Full Text Available Tissue barriers function as “gate keepers” between different compartments (usually blood and tissue and are formed by specialised membrane-associated proteins, localising to the apicolateral plasma membrane domain of epithelial and endothelial cells. By sealing the paracellular space, the free diffusion of solutes and molecules across epithelia and endothelia is impeded. Thereby, tissue barriers contribute to the establishment and maintenance of a distinct internal and external environment, which is crucial during organ development and allows maintenance of an organ-specific homeostatic milieu. So far, various epithelial and endothelial tissue barriers have been described, including the blood-brain barrier, the blood-retina barrier, the blood-testis barrier, the blood-placenta barrier, and the cerebrospinal fluid (CSF-brain barrier, which are vital for physiological function and any disturbance of these barriers can result in severe organ damage or even death. Here, we describe the identification of a novel barrier, located in the vascular bed of tendons, which we term the blood-tendon barrier (BTB. By using immunohistochemistry, transmission electron microscopy, and tracer studies we demonstrate the presence of a functional endothelial barrier within tendons restricting the passage of large blood-borne molecules into the surrounding tendon tissue. We further provide in vitro evidence that the BTB potentially contributes to the creation of a distinct internal tissue environment impacting upon the proliferation and differentiation of tendon-resident cells, effects which might be fundamental for the onset of tendon pathologies.

  18. Distribution of normal superficial ocular vessels in digital images.

    Science.gov (United States)

    Banaee, Touka; Ehsaei, Asieh; Pourreza, Hamidreza; Khajedaluee, Mohammad; Abrishami, Mojtaba; Basiri, Mohsen; Daneshvar Kakhki, Ramin; Pourreza, Reza

    2014-02-01

    To investigate the distribution of different-sized vessels in the digital images of the ocular surface, an endeavor which may provide useful information for future studies. This study included 295 healthy individuals. From each participant, four digital photographs of the superior and inferior conjunctivae of both eyes, with a fixed succession of photography (right upper, right lower, left upper, left lower), were taken with a slit lamp mounted camera. Photographs were then analyzed by a previously described algorithm for vessel detection in the digital images. The area (of the image) occupied by vessels (AOV) of different sizes was measured. Height, weight, fasting blood sugar (FBS) and hemoglobin levels were also measured and the relationship between these parameters and the AOV was investigated. These findings indicated a statistically significant difference in the distribution of the AOV among the four conjunctival areas. No significant correlations were noted between the AOV of each conjunctival area and the different demographic and biometric factors. Medium-sized vessels were the most abundant vessels in the photographs of the four investigated conjunctival areas. The AOV of the different sizes of vessels follows a normal distribution curve in the four areas of the conjunctiva. The distribution of the vessels in successive photographs changes in a specific manner, with the mean AOV becoming larger as the photos were taken from the right upper to the left lower area. The AOV of vessel sizes has a normal distribution curve and medium-sized vessels occupy the largest area of the photograph. Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  19. Modeling the Thermal Mechanical Behavior of a 300 K Vacuum Vessel that is Cooled by Liquid Hydrogen in Film Boiling

    International Nuclear Information System (INIS)

    Yang, S.Q.; Green, M.A.; Lau, W.

    2004-01-01

    This report discusses the results from the rupture of a thin window that is part of a 20-liter liquid hydrogen vessel. This rupture will spill liquid hydrogen onto the walls and bottom of a 300 K cylindrical vacuum vessel. The spilled hydrogen goes into film boiling, which removes the thermal energy from the vacuum vessel wall. This report analyzes the transient heat transfer in the vessel and calculates the thermal deflection and stress that will result from the boiling liquid in contact with the vessel walls. This analysis was applied to aluminum and stainless steel vessels

  20. Coxsackie- and adenovirus receptor (CAR) is expressed in lymphatic vessels in human skin and affects lymphatic endothelial cell function in vitro

    International Nuclear Information System (INIS)

    Vigl, Benjamin; Zgraggen, Claudia; Rehman, Nadia; Banziger-Tobler, Nadia E.; Detmar, Michael; Halin, Cornelia

    2009-01-01

    Lymphatic vessels play an important role in tissue fluid homeostasis, intestinal fat absorption and immunosurveillance. Furthermore, they are involved in pathologic conditions, such as tumor cell metastasis and chronic inflammation. In comparison to blood vessels, the molecular phenotype of lymphatic vessels is less well characterized. Performing comparative gene expression analysis we have recently found that coxsackie- and adenovirus receptor (CAR) is significantly more highly expressed in cultured human, skin-derived lymphatic endothelial cells (LECs), as compared to blood vascular endothelial cells. Here, we have confirmed these results at the protein level, using Western blot and FACS analysis. Immunofluorescence performed on human skin confirmed that CAR is expressed at detectable levels in lymphatic vessels, but not in blood vessels. To address the functional significance of CAR expression, we modulated CAR expression levels in cultured LECs in vitro by siRNA- and vector-based transfection approaches. Functional assays performed with the transfected cells revealed that CAR is involved in distinct cellular processes in LECs, such as cell adhesion, migration, tube formation and the control of vascular permeability. In contrast, no effect of CAR on LEC proliferation was observed. Overall, our data suggest that CAR stabilizes LEC-LEC interactions in the skin and may contribute to lymphatic vessel integrity