Preceding bronchial cutting for exposure of the pulmonary artery buried in scar tissue after chemoradiotherapy.

Science.gov (United States)

Nomori, Hiroaki; Cong, Yue; Sugimura, Hiroshi

2017-01-01

It is often difficult to expose the pulmonary artery buried in a scar tissue, especially in lung cancer patients that responded well to neoadjuvant chemoradiotherapy. Difficulty to access pulmonary artery branches may lead to potentially unnecessary pneumonectomy. To complete lobectomy in such cases, a technique with preceding bronchial cutting for exposure of the pulmonary artery is presented. After dissecting the pulmonary vein, the lobar bronchus is cut from the opposite side of the pulmonary artery with scissors. The back wall of the lobar bronchus is cut using a surgical knife from the luminal face, which can expose the pulmonary artery behind the bronchial stump and then complete lobectomy. Fourteen patients have been treated using the present technique, enabling complete resection by lobectomy (including sleeve lobectomy in 3 patients) without major bleeding. The present procedure can expose pulmonary artery buried in scar tissue, resulting in making the lobectomy safer.

Global gene expression profiling displays a network of dysregulated genes in non-atherosclerotic arterial tissue from patients with type 2 diabetes

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Skov Vibe

2012-02-01

Full Text Available Abstract Background Generalized arterial alterations, such as endothelial dysfunction, medial matrix accumulations, and calcifications are associated with type 2 diabetes (T2D. These changes may render the vessel wall more susceptible to injury; however, the molecular characteristics of such diffuse pre-atherosclerotic changes in diabetes are only superficially known. Methods To identify the molecular alterations of the generalized arterial disease in T2D, DNA microarrays were applied to examine gene expression changes in normal-appearing, non-atherosclerotic arterial tissue from 10 diabetic and 11 age-matched non-diabetic men scheduled for a coronary by-pass operation. Gene expression changes were integrated with GO-Elite, GSEA, and Cytoscape to identify significant biological pathways and networks. Results Global pathway analysis revealed differential expression of gene-sets representing matrix metabolism, triglyceride synthesis, inflammation, insulin signaling, and apoptosis. The network analysis showed a significant cluster of dysregulated genes coding for both intra- and extra-cellular proteins associated with vascular cell functions together with genes related to insulin signaling and matrix remodeling. Conclusions Our results identify pathways and networks involved in the diffuse vasculopathy present in non-atherosclerotic arterial tissue in patients with T2D and confirmed previously observed mRNA-alterations. These abnormalities may play a role for the arterial response to injury and putatively for the accelerated atherogenesis among patients with diabetes.

Evidence for reduced arterial plasma input, prolonged lung retention and reduced lung monoamine oxidase in smokers

International Nuclear Information System (INIS)

Logan, Jean; Fowler, Joanna S.

2005-01-01

We have previously found that smokers have reduced brain monoamine oxidase (MAO) A and B using positron emission tomography (PET) and the irreversible mechanism-based radiotracers [ 11 C]-labeled clorgyline (CLG) and deprenyl (DEP) and their deuterated analogs (D CLG, D DEP). More recently, we have estimated MAO A and B activity in other organs using the deuterium isotope effect to determine binding specificity for MAO and a three-compartment model to estimate k 3 , the model term proportional to MAO A activity. Here, we have investigated the robustness of the model term k 3 for estimating lung MAO A and B in light of our unexpected finding that lung MAO activity (k 3 ) was reduced for smokers relative to nonsmokers, although radiotracer uptake in the lungs was similar at peak and plateau for the two groups. Methods: Time-activity data from lung and arterial plasma were used from seven nonsmokers and seven smokers scanned previously with CLG and D CLG, and five nonsmokers and nine smokers scanned previously with DEP and D DEP. The measured time-activity curves for lung and plasma and the integrals for the arterial plasma time-activity curves were compared at an early time point (2.5 min) and at the end of the study (55 min). A three-compartment irreversible model was used to estimate the differences between smokers and nonsmokers, and the stability of the parameter (k 3 ) while varying model assumptions for the relative fractions of lung tissue, blood and air in the PET voxel. Results: The peak in the arterial plasma input function and the integral of the arterial plasma time-activity curve over the first 2.5 min after radiotracer injection were significantly lower for smokers relative to nonsmokers for all four tracers. However, although the peak and plateau of the lung time-activity curves were similar for smokers and nonsmokers, the decline in radioactivity from peak to plateau was slower for smokers for all tracers. Using a three-compartment irreversible model

Individual Case Analysis of Postmortem Interval Time on Brain Tissue Preservation.

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Jeffrey A Blair

Full Text Available At autopsy, the time that has elapsed since the time of death is routinely documented and noted as the postmortem interval (PMI. The PMI of human tissue samples is a parameter often reported in research studies and comparable PMI is preferred when comparing different populations, i.e., disease versus control patients. In theory, a short PMI may alleviate non-experimental protein denaturation, enzyme activity, and other chemical changes such as the pH, which could affect protein and nucleic acid integrity. Previous studies have compared PMI en masse by looking at many different individual cases each with one unique PMI, which may be affected by individual variance. To overcome this obstacle, in this study human hippocampal segments from the same individuals were sampled at different time points after autopsy creating a series of PMIs for each case. Frozen and fixed tissue was then examined by Western blot, RT-PCR, and immunohistochemistry to evaluate the effect of extended PMI on proteins, nucleic acids, and tissue morphology. In our results, immunostaining profiles for most proteins remained unchanged even after PMI of over 50 h, yet by Western blot distinctive degradation patterns were observed in different protein species. Finally, RNA integrity was lower after extended PMI; however, RNA preservation was variable among cases suggesting antemortem factors may play a larger role than PMI in protein and nucleic acid integrity.

Analysis of transit time flow of the right internal thoracic artery anastomosed to the left anterior descending artery compared to the left internal thoracic artery

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Milani, Rodrigo; de Moraes, Daniela; Sanches, Aline; Jardim, Rodrigo; Lumikoski, Thais; Miotto, Gabriela; Santana, Vitor Hugo; Brofman, Paulo Roberto

2014-01-01

Introduction We evaluated with transit time flow the performance of the right and left thoracic arteries when used as a graft for the left anterior descending artery. Methods Fifty patients undergoing surgery for myocardial revascularization without cardiopulmonary bypass were divided into two groups. In group A patients received graft of right internal mammary artery to the anterior interventricular branch. In group B patients received graft of left internal mammary artery to the same branch. At the end of the operation the flow was assessed by measuring transit time. Results In group A, mean age was 60.6±9.49 years. The average height and weight of the group was 80.4±10.32 kg and 169.2±6.86 cm. The average number of grafts per patient in this group was 3.28±1.49. The mean flow and distal resistance obtained in right internal thoracic artery was 42.1±23.4 ml/min and 2.8±0.9 respectively. In group B, the mean age was 59.8±9.7 years. The average height and weight of this group was 77.7±14.22 kg and 166.0±8.2 cm. The average number of grafts per patient in this group was 3.08 ±0.82. The mean flow and distal resistance observed in this group was 34.2±19.1 ml/min and 2.0±0.7. There were no deaths in this series. Conclusion Right internal mammary artery presented a similar behavior to left internal mammary artery when anastomosed to the anterior interventricular branch of the left coronary artery. There was no statistical difference between the measured flow obtained between both arteries. PMID:25140463

Three-dimensional analysis and classification of arteries in the skin and subcutaneous adipofascial tissue by computer graphics imaging.

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Nakajima, H; Minabe, T; Imanishi, N

1998-09-01

To develop new types of surgical flaps that utilize portions of the skin and subcutaneous tissue (e.g., a thin flap or an adipofascial flap), three-dimensional investigation of the vasculature in the skin and subcutaneous tissue has been anticipated. In the present study, total-body arterial injection and three-dimensional imaging of the arteries by computer graphics were performed. The full-thickness skin and subcutaneous adipofascial tissue samples, which were obtained from fresh human cadavers injected with radio-opaque medium, were divided into three distinct layers. Angiograms of each layer were introduced into a personal computer to construct three-dimensional images. On a computer monitor, each artery was shown color-coded according to the three portions: the deep adipofascial layer, superficial adipofascial layer, and dermis. Three-dimensional computerized images of each artery in the skin and subcutaneous tissue revealed the components of each vascular plexus and permitted their classification into six types. The distribution of types in the body correlated with the tissue mobility of each area. Clinically, appreciation of the three-dimensional structure of the arteries allowed the development of several new kinds of flaps.

Conformally integrated stent cell resonators for wireless monitoring of peripheral artery disease

KAUST Repository

Viswanath, Anupam

2013-01-01

This paper presents the design and in vitro evaluation of magnetoelastic sensors intended for wireless monitoring of tissue accumulation in peripheral artery stents. The sensors, shaped like stent cells, are fabricated from 28-μm thick foils of magnetoelastic Ni-Fe alloy and are conformally integrated with the stent. The typical sensitivity to viscosity is 427 ppm/cP over a 1.1-8.6 cP range. The sensitivity to mass loading is typically 63,000-65000 ppm/mg with resonant frequency showing an 8.1% reduction for an applied mass that is 15% of the unloaded mass of the sensor. © 2013 IEEE.

Combined Monte Carlo and path-integral method for simulated library of time-resolved reflectance curves from layered tissue models

Science.gov (United States)

Wilson, Robert H.; Vishwanath, Karthik; Mycek, Mary-Ann

2009-02-01

Monte Carlo (MC) simulations are considered the "gold standard" for mathematical description of photon transport in tissue, but they can require large computation times. Therefore, it is important to develop simple and efficient methods for accelerating MC simulations, especially when a large "library" of related simulations is needed. A semi-analytical method involving MC simulations and a path-integral (PI) based scaling technique generated time-resolved reflectance curves from layered tissue models. First, a zero-absorption MC simulation was run for a tissue model with fixed scattering properties in each layer. Then, a closed-form expression for the average classical path of a photon in tissue was used to determine the percentage of time that the photon spent in each layer, to create a weighted Beer-Lambert factor to scale the time-resolved reflectance of the simulated zero-absorption tissue model. This method is a unique alternative to other scaling techniques in that it does not require the path length or number of collisions of each photon to be stored during the initial simulation. Effects of various layer thicknesses and absorption and scattering coefficients on the accuracy of the method will be discussed.

Trans-activation function of a 3' truncated X gene-cell fusion product from integrated hepatitis B virus DNA in chronic hepatitis tissues

International Nuclear Information System (INIS)

Takada, Shinako; Koike, Katsuro

1990-01-01

To investigate the expression and transactivation function of the X gene in integrated hepatitis B virus (HBV) DNA from chronic hepatitis tissues, a series of transfectants containing cloned integrated HBV DNAs was made and analyzed for X mRNA expression and trans-activation activity by using a chloramphenicol acetyltransferase assay. Most of the integrated HBV DNAs expressed X mRNA and encoded a product with trans-activation activity in spite of the loss of the 3' end region of the X gene due to integration. From cDNA cloning and sequence analysis of X mRNA transcribed from native or integrated HBV DNA, the X protein was found to be translated from the X open reading frame without splicing. For integrated HBV DNA, transcription was extended to a cellular flanking DNA and an X gene-cell fusion transcript was terminated by using a cellular poly(A) signal. The amino acid sequence deduced from an X-cell fusion transcript indicated truncation of the carboxyl-terminal five amino acids, but the upstream region of seven amino acids conserved among hepadnaviruses was retained in the integrated HBV DNA, suggesting that this conserved region is essential for the transactivation function of the X protein. These findings support the following explanation for hepatocarcinogenesis by HBV DNA integration: the expression of a cellular oncogene(s) is transactivated at the time of chronic infection by the increasing amounts of the integrated HBV gene product(s), such as the X-cell fusion product

Classification of coronary artery tissues using optical coherence tomography imaging in Kawasaki disease

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Abdolmanafi, Atefeh; Prasad, Arpan Suravi; Duong, Luc; Dahdah, Nagib

2016-03-01

Intravascular imaging modalities, such as Optical Coherence Tomography (OCT) allow nowadays improving diagnosis, treatment, follow-up, and even prevention of coronary artery disease in the adult. OCT has been recently used in children following Kawasaki disease (KD), the most prevalent acquired coronary artery disease during childhood with devastating complications. The assessment of coronary artery layers with OCT and early detection of coronary sequelae secondary to KD is a promising tool for preventing myocardial infarction in this population. More importantly, OCT is promising for tissue quantification of the inner vessel wall, including neo intima luminal myofibroblast proliferation, calcification, and fibrous scar deposits. The goal of this study is to classify the coronary artery layers of OCT imaging obtained from a series of KD patients. Our approach is focused on developing a robust Random Forest classifier built on the idea of randomly selecting a subset of features at each node and based on second- and higher-order statistical texture analysis which estimates the gray-level spatial distribution of images by specifying the local features of each pixel and extracting the statistics from their distribution. The average classification accuracy for intima and media are 76.36% and 73.72% respectively. Random forest classifier with texture analysis promises for classification of coronary artery tissue.

Relation of epicardial adipose tissue with arterial compliance and stiffness in patients with hypertension.

Science.gov (United States)

Korkmaz, Levent; Cirakoglu, Omer Faruk; Ağaç, Mustafa Tarik; Erkan, Hakan; Korkmaz, Ayca Ata; Acar, Zeydin; Kul, Selim; Hatem, Engin; Çelik, Şükrü

2014-09-01

The main aim of the present study was to investigate the association between epicardial adipose tissue (EAT) and arterial function in patients with asymptomatic hypertension. Patients with hypertension (n = 155) were enrolled consecutively. Patients with decreased arterial compliance (AC) and increased cardioankle vascular index (CAVI) had higher EAT values compared with those with normal AC and CAVI (6.23 ± 1.67 vs 4.91 ± 1.40, P arterial function in patients with asymptomatic hypertension. The link between EAT and arterial stiffness deserves further investigation. © The Author(s) 2013.

Impaired activity of adherens junctions contributes to endothelial dilator dysfunction in ageing rat arteries.

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Chang, Fumin; Flavahan, Sheila; Flavahan, Nicholas A

2017-08-01

Ageing-induced endothelial dysfunction contributes to organ dysfunction and progression of cardiovascular disease. VE-cadherin clustering at adherens junctions promotes protective endothelial functions, including endothelium-dependent dilatation. Ageing increased internalization and degradation of VE-cadherin, resulting in impaired activity of adherens junctions. Inhibition of VE-cadherin clustering at adherens junctions (function-blocking antibody; FBA) reduced endothelial dilatation in young arteries but did not affect the already impaired dilatation in old arteries. After junctional disruption with the FBA, dilatation was similar in young and old arteries. Src tyrosine kinase activity and tyrosine phosphorylation of VE-cadherin were increased in old arteries. Src inhibition increased VE-cadherin at adherens junctions and increased endothelial dilatation in old, but not young, arteries. Src inhibition did not increase dilatation in old arteries treated with the VE-cadherin FBA. Ageing impairs the activity of adherens junctions, which contributes to endothelial dilator dysfunction. Restoring the activity of adherens junctions could be of therapeutic benefit in vascular ageing. Endothelial dilator dysfunction contributes to pathological vascular ageing. Experiments assessed whether altered activity of endothelial adherens junctions (AJs) might contribute to this dysfunction. Aortas and tail arteries were isolated from young (3-4 months) and old (22-24 months) F344 rats. VE-cadherin immunofluorescent staining at endothelial AJs and AJ width were reduced in old compared to young arteries. A 140 kDa VE-cadherin species was present on the cell surface and in TTX-insoluble fractions, consistent with junctional localization. Levels of the 140 kDa VE-cadherin were decreased, whereas levels of a TTX-soluble 115 kDa VE-cadherin species were increased in old compared to young arteries. Acetylcholine caused endothelium-dependent dilatation that was decreased in old

Molecular radiotherapy: The NUKFIT software for calculating the time-integrated activity coefficient

Energy Technology Data Exchange (ETDEWEB)

Kletting, P.; Schimmel, S.; Luster, M. [Klinik für Nuklearmedizin, Universität Ulm, Ulm 89081 (Germany); Kestler, H. A. [Research Group Bioinformatics and Systems Biology, Institut für Neuroinformatik, Universität Ulm, Ulm 89081 (Germany); Hänscheid, H.; Fernández, M.; Lassmann, M. [Klinik für Nuklearmedizin, Universität Würzburg, Würzburg 97080 (Germany); Bröer, J. H.; Nosske, D. [Bundesamt für Strahlenschutz, Fachbereich Strahlenschutz und Gesundheit, Oberschleißheim 85764 (Germany); Glatting, G. [Medical Radiation Physics/Radiation Protection, Medical Faculty Mannheim, Heidelberg University, Mannheim 68167 (Germany)

2013-10-15

Purpose: Calculation of the time-integrated activity coefficient (residence time) is a crucial step in dosimetry for molecular radiotherapy. However, available software is deficient in that it is either not tailored for the use in molecular radiotherapy and/or does not include all required estimation methods. The aim of this work was therefore the development and programming of an algorithm which allows for an objective and reproducible determination of the time-integrated activity coefficient and its standard error.Methods: The algorithm includes the selection of a set of fitting functions from predefined sums of exponentials and the choice of an error model for the used data. To estimate the values of the adjustable parameters an objective function, depending on the data, the parameters of the error model, the fitting function and (if required and available) Bayesian information, is minimized. To increase reproducibility and user-friendliness the starting values are automatically determined using a combination of curve stripping and random search. Visual inspection, the coefficient of determination, the standard error of the fitted parameters, and the correlation matrix are provided to evaluate the quality of the fit. The functions which are most supported by the data are determined using the corrected Akaike information criterion. The time-integrated activity coefficient is estimated by analytically integrating the fitted functions. Its standard error is determined assuming Gaussian error propagation. The software was implemented using MATLAB.Results: To validate the proper implementation of the objective function and the fit functions, the results of NUKFIT and SAAM numerical, a commercially available software tool, were compared. The automatic search for starting values was successfully tested for reproducibility. The quality criteria applied in conjunction with the Akaike information criterion allowed the selection of suitable functions. Function fit

H ∞ synchronization of the coronary artery system with input time-varying delay

International Nuclear Information System (INIS)

Li Xiao-Meng; Zhao Zhan-Shan; Sun Lian-Kun; Zhang Jing

2016-01-01

This paper investigates the H ∞ synchronization of the coronary artery system with input delay and disturbance. We focus on reducing the conservatism of existing synchronization strategies. Base on the triple integral forms of the Lyapunov–Krasovskii functional (LKF), we utilize single and double integral forms of Wirtinger-based inequality to guarantee that the synchronization feedback controller has good performance against time-varying delay and external disturbance. The effectiveness of our strategy can be exhibited by simulations under the different time-varying delays and different disturbances. (paper)

Histomorphometric Evaluation of the Small Coronary Arteries in Rats Exposed to Industrial Noise

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Ana Lousinha

2015-05-01

Full Text Available Morphological changes induced by industrial noise (IN have been experimentally observed in several organs. Histological observations of the coronary arteries showed prominent perivascular tissue and fibrosis among IN-exposed rats. The effects on the small arteries are unknown. Objective: To evaluate the histomorphometric changes induced by IN on rat heart small arteries. Methods: Twenty Wistar rats exposed to IN during a maximum period of seven months and 20 age-matched controls were studied. Hearts were transversely sectioned from ventricular apex to atria and a mid-ventricular fragment was selected for analysis. The histological images were obtained with an optical microscope using 400× magnifications. A total of 634 arterial vessels (298 IN-exposed and 336 controls were selected. The mean lumen-to-vessel wall (L/W and mean vessel wall-to-perivascular tissue (W/P ratios were calculated using image J software. Results: There were no differences between exposed and control animals in their L/W ratios (p = 0.687 and time variations in this ratio were non-significant (p = 0.110. In contrast, exposed animals showed lower W/P ratios than control animals (p < 0.001, with significant time variations (p = 0.004. Conclusions: Industrial noise induced an increase in the perivascular tissue of rat small coronary arteries, with significant development of periarterial fibrosis.

[Repair of soft tissue defect in hand or foot with lobulated medial sural artery perforator flap].

Science.gov (United States)

Fengjing, Zhao; Jianmin, Yao; Xingqun, Zhang; Liang, Ma; Longchun, Zhang; Yibo, Xu; Peng, Wang; Zhen, Zhu

2015-11-01

To explore the clinical effect of the lobulated medial sural artery perforator flap in repairing soft tissue defect in hand or foot. Since March 2012 to September 2014, 6 cases with soft tissue defects in hands or feet were treated by lobulated medial sural artery flaps pedicled with 1st musculo-cutaneous perforator and 2st musculo-cutaneous perforator of the medial sural artery. The size of the flaps ranged from 4.5 cm x 10.0 cm to 6.0 cm x 17.0 cm. 5 cases of lobulated flap survived smoothly, only 1 lobulated flap had venous articulo, but this flap also survived after the articulo was removed by vascular exploration. All flaps had desirable appearance and sensation and the two-point discrimination was 6 mm in mean with 4 to 12 months follow-up (average, 7 months). Linear scar was left in donor sites in 3 cases and skin scar in 3 cases. There was no malfunction in donor sites. Lobulated medial sural artery perforator flap is feasible and ideal method for the treatment of soft tissue defect in hand or foot with satisfactory effect.

Molecular radiotherapy: the NUKFIT software for calculating the time-integrated activity coefficient.

Science.gov (United States)

Kletting, P; Schimmel, S; Kestler, H A; Hänscheid, H; Luster, M; Fernández, M; Bröer, J H; Nosske, D; Lassmann, M; Glatting, G

2013-10-01

Calculation of the time-integrated activity coefficient (residence time) is a crucial step in dosimetry for molecular radiotherapy. However, available software is deficient in that it is either not tailored for the use in molecular radiotherapy and/or does not include all required estimation methods. The aim of this work was therefore the development and programming of an algorithm which allows for an objective and reproducible determination of the time-integrated activity coefficient and its standard error. The algorithm includes the selection of a set of fitting functions from predefined sums of exponentials and the choice of an error model for the used data. To estimate the values of the adjustable parameters an objective function, depending on the data, the parameters of the error model, the fitting function and (if required and available) Bayesian information, is minimized. To increase reproducibility and user-friendliness the starting values are automatically determined using a combination of curve stripping and random search. Visual inspection, the coefficient of determination, the standard error of the fitted parameters, and the correlation matrix are provided to evaluate the quality of the fit. The functions which are most supported by the data are determined using the corrected Akaike information criterion. The time-integrated activity coefficient is estimated by analytically integrating the fitted functions. Its standard error is determined assuming Gaussian error propagation. The software was implemented using MATLAB. To validate the proper implementation of the objective function and the fit functions, the results of NUKFIT and SAAM numerical, a commercially available software tool, were compared. The automatic search for starting values was successfully tested for reproducibility. The quality criteria applied in conjunction with the Akaike information criterion allowed the selection of suitable functions. Function fit parameters and their standard

SECONDARY PULMONARY ARTERIAL HYPERTENSION IN SYSTEMIC DISEASES OF CONNECTIVE TISSUE

Directory of Open Access Journals (Sweden)

N. A. Shostak

2016-01-01

Full Text Available Modern definition of pulmonary arterial hypertension (PAH as well as data on prevalence and incidence of secondary PAH in systemic disease of connective tissue is presented,  including data of USA, France and Scotland registers. The main chains of pathogenesis, classification approaches, clinical features and diagnostics are described. 

SECONDARY PULMONARY ARTERIAL HYPERTENSION IN SYSTEMIC DISEASES OF CONNECTIVE TISSUE

Directory of Open Access Journals (Sweden)

N. A. Shostak

2009-01-01

Full Text Available Modern definition of pulmonary arterial hypertension (PAH as well as data on prevalence and incidence of secondary PAH in systemic disease of connective tissue is presented,  including data of USA, France and Scotland registers. The main chains of pathogenesis, classification approaches, clinical features and diagnostics are described. 

Access to destinations : arterial data acquisition and network-wide travel time estimation (phase II).

Science.gov (United States)

2010-03-01

The objectives of this project were to (a) produce historic estimates of travel times on Twin-Cities arterials : for 1995 and 2005, and (b) develop an initial architecture and database that could, in the future, produce timely : estimates of arterial...

[Characteristics of porcine thoracic arteries fixed with polyepoxy compound].

Science.gov (United States)

Yu, Xi-Xun; Chen, Huai-Qing

2005-09-01

To investigate the characteristics of porcine thoracic arteries fixed with ethylene glycol diglycidyl ether (EX-810) and to provide the proper scaffold materials for tissue-engineered blood vessel. The porcine thoracic arteries were respectively treated with 40 ml/L EX-810 and 6.25 g/L glutaraldehyde, and then they were examined with naked-eye, light microscope and scanning electron microscope. The fixation index determination, the amino acid analysis and the biomechanics test were also performed. The antigenicity of vascular tissues can be diminished by EX-810 through getting rid of cell in the vascular tissues or reducing the level of free amino groups in the vascular tissues. The structural integrity of vascular tissues can be preserved after treatment with EX-810. It was also found that the EX-810-fixed porcine vascular tissues appeared more similar to the natural vascular tissues in color and mechanical properties, and were more pliable than the glutaraldehyde-fixed tissues. The EX-810-fixed porcine thoracic arteries with low cytotoxicity and low antigenicity showed favorable characteristic similar to those of natural vessel, and it should be a promising material for fabricating scaffold of tissue-engineered blood vessel.

Imaging experimental coronary artery thrombosis with indium-111 platelets

International Nuclear Information System (INIS)

Riba, A.L.; Thakur, M.L.; Gottschalk, A.; Zaret, B.L.

1979-01-01

The ability of cardiac scintigraphy with indium-111 ( 111 In)-labeled platelets to detect coronary artery thrombosis (CAT) was assessed in a canine model. Cardiac imaging and tissue distribution studies were performed shortly after administering 111 In-labeled platelets to 12 dogs (group 1) with acute CAT. Four dogs (group 2) with acute CAT were studied 2 and 22 hours after administering 111 In platelets. In addition, four dogs (group 3) with 24-hour-old CAT were similarly evaluated. In all group 1 animals, in vivo imaging 1 to 2 hours after 111 In platelet administration revealed intense uptake in the region of thrombus-containing left anterior descending arteries that was readily discernible from background blood pool activity. Sequential imaging of the four group 2 animals over a 22-hour period revealed no change in the scintigraphic pattern of the thrombosed arteries. In contrast, 111 In platelet imaging in the four group 3 animals with 24-hour-old CAT failed to reveal enhanced activity within the region of the thrombus-containing coronary artery. In the 12 group 1 animals, the CAT accumulated 69 +- 10 (mean +- SEM) times greater activity than present in blood and 651 +- 135 times greater activity than normal left ventricular myocardium. There was 24 +- 7 times greater 111 In activity in the damaged left anterior descending arteries compared with normal circumflex arteries. Similar uptake ratios were seen in group 2 animals. The 24-hour old thrombi from group 3 animals showed no enhanced 111 In uptake. This study demonstrates that experimental acute CAT can be detected readily with 111 In platelet cardiac scintigraphy

Arterial properties in acromegaly: relation to disease activity and associated cardiovascular risk factors.

Science.gov (United States)

Yaron, Marianna; Izkhakov, Elena; Sack, Jessica; Azzam, Ibrahim; Osher, Etty; Tordjman, Karen; Stern, Naftali; Greenman, Yona

2016-06-01

Acromegaly is associated with increased cardiovascular morbidity and mortality when inadequately treated, which may be secondary to associated comorbidities or to direct IGF-1 effects on the cardiovascular system. By using a control group carefully matched for traditional cardiovascular risk factors, we aimed to assess the direct contribution of disease activity and IGF-1 levels to arterial damage as assessed by measurements of arterial stiffness and endothelial function. Twenty-nine subjects with acromegaly (11 males, 52 ± 14 year; 15 active acromegaly) and 24 matched controls underwent evaluation of large and small artery compliance using applanation tonometry, pulse wave velocity (PWV), augmentation index (Alx), carotid ultrasonography intima-media thickness, (IMT) and flow-mediated dilatation (FMD). IGF-1 expressed as times the upper limit of the normal range (x ULN) was 2.2 ± 1.1 in patients with active disease versus 0.7 ± 0.2 in patients in remission. Irrespective of disease activity, FMD was lower in patients with acromegaly than in control subjects, (3.4 ± 2.7 % in active acromegaly, 4.4 ± 3.3 % in controlled acromegaly and 7.5 ± 3.8 % in controls; p = 0.004). There were no significant differences in PWV, Alx, and IMT between groups. A positive correlation was found between IGF-1× ULN and IMT (r = 0.4; P = 0.02). Asymmetric dimethylarginine (ADMA), a novel cardiovascular risk factor, was positively correlated to arterial stiffness (r = 0.46; p = 0.017) and negatively with small vessel compliance (r = -0.44, p = 0.02). Patients with acromegaly have significantly impaired endothelial function as assessed by FMD, but other tested vascular parameters were similar to a control group that was adequately matched for cardiovascular risk factors.

Sickle Mice Are Sensitive to Hypoxia/Ischemia-Induced Stroke but Respond to Tissue-Type Plasminogen Activator Treatment.

Science.gov (United States)

Sun, Yu-Yo; Lee, Jolly; Huang, Henry; Wagner, Mary B; Joiner, Clinton H; Archer, David R; Kuan, Chia-Yi

2017-12-01

The effects of lytic stroke therapy in patients with sickle cell anemia are unknown, although a recent study suggested that coexistent sickle cell anemia does not increase the risk of cerebral hemorrhage. This finding calls for systemic analysis of the effects of thrombolytic stroke therapy, first in humanized sickle mice, and then in patients. There is also a need for additional predictive markers of sickle cell anemia-associated vasculopathy. We used Doppler ultrasound to examine the carotid artery of Townes sickle mice tested their responses to repetitive mild hypoxia-ischemia- and transient hypoxia-ischemia-induced stroke at 3 or 6 months of age, respectively. We also examined the effects of tPA (tissue-type plasminogen activator) treatment in transient hypoxia-ischemia-injured sickle mice. Three-month-old sickle cell (SS) mice showed elevated resistive index in the carotid artery and higher sensitivity to repetitive mild hypoxia-ischemia-induced cerebral infarct. Six-month-old SS mice showed greater resistive index and increased flow velocity without obstructive vasculopathy in the carotid artery. Instead, the cerebral vascular wall in SS mice showed ectopic expression of PAI-1 (plasminogen activator inhibitor-1) and P-selectin, suggesting a proadhesive and prothrombotic propensity. Indeed, SS mice showed enhanced leukocyte and platelet adherence to the cerebral vascular wall, broader fibrin deposition, and higher mortality after transient hypoxia-ischemia. Yet, post-transient hypoxia-ischemia treatment with tPA reduced thrombosis and mortality in SS mice. Sickle mice are sensitive to hypoxia/ischemia-induced cerebral infarct but benefit from thrombolytic treatment. An increased resistive index in carotid arteries may be an early marker of sickle cell vasculopathy. © 2017 American Heart Association, Inc.

Plasma Tissue Factor Pathway Inhibitor Levels in Angiographically Defined Coronary Artery Disease Among Saudis

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Syed Shahid Habib

2013-05-01

Full Text Available Objectives: This study was aimed to determine plasma levels of total (TFPI-T and free (TFPI-F tissue factor pathway inhibitor, plasminogen activator inhibitor-1 (PAI-1, and tissue plasminogen activator (t-PA in a cohort of Saudi patients with chronic stable angiographically defined coronary artery disease (CAD and to determine its correlation with its severity.Methods: This cross sectional study was conducted in the department of physiology and department of cardiology, College of Medicine, and King Khalid University Hospital and King Saud University, Riyadh. Sixty known cases of CAD who had undergone angiography (35 males and 25 females were selected. A control group included 39 (20 males and 19 females healthy subjects. Fasting venous blood samples were analyzed for total (TFPI-T and free (TFPI-F tissue factor pathway inhibitor, plasminogen activator inhibitor-1 (PAI-1, and tissue plasminogen activator (t-PA. Gensini scores and vessel scores were determined for assessing CAD severity.Results: There were non-significant differences between age, body mass index (BMI and Blood pressure between the controls and CAD subjects. A comparison of hemostatic markers between control and CAD patients showed significantly higher levels of Fibrinogen, PAI-1, TFPI-T and TFPI-F in CAD patients compared to control subjects. But there was no difference in plasma t-PA levels. TFPI-T had a significant positive correlation with severity of disease determined by Gensini Scores (r=0.344; p=0.006 and vessel scores (r=0.338; p=0.015.Conclusion: Plasma levels of total tissue factor pathway inhibitor are significantly related with the presence and severity of CAD. Elevated levels of TFPI-T may be considered as useful diagnostic and prognostic markers in patients with CAD.

Mediastinal lymphadenopathy and pulmonary arterial hypertension in mixed connective tissue disease

International Nuclear Information System (INIS)

Guit, G.L.; Shaw, P.C.; Ehrlich, J.; Kroon, H.M.; Oudkerk, M.

1985-01-01

A case of mixed connective tissue disease (MCTD) is presented in which mediastinal lymphadenopathy was the most prominent radiological finding detected by plain chest radiographs and computed tomography. Pulmonary arterial hypertension, which is a rare and often fatal complication of MCTD, also developed in this patient

Carbon Dioxide Flush of an Integrated Minimized Perfusion Circuit Prior to Priming Prevents Spontaneous Air Release Into the Arterial Line During Clinical Use.

Science.gov (United States)

Stehouwer, Marco C; de Vroege, Roel; Hoohenkerk, Gerard J F; Hofman, Frederik N; Kelder, Johannes C; Buchner, Bas; de Mol, Bastian A; Bruins, Peter

2017-11-01

Recently, an oxygenator with an integrated centrifugal blood pump (IP) was designed to minimize priming volume and to reduce blood foreign surface contact even further. The use of this oxygenator with or without integrated arterial filter was compared with a conventional oxygenator and nonintegrated centrifugal pump. To compare the air removal characteristics 60 patients undergoing coronary artery bypass grafting were alternately assigned into one of three groups to be perfused with a minimized extracorporeal circuit either with the conventional oxygenator, the oxygenator with IP, or the oxygenator with IP plus integrated arterial filter (IAF). Air entering and leaving the three devices was measured accurately with a bubble counter during cardiopulmonary bypass. No significant differences between all groups were detected, considering air entering the devices. Our major finding was that in both integrated devices groups incidental spontaneous release of air into the arterial line in approximately 40% of the patients was observed. Here, detectable bolus air (>500 µm) was shown in the arterial line, whereas in the minimal extracorporeal circulation circuit (MECC) group this phenomenon was not present. We decided to conduct an amendment of the initial design with METC-approval. Ten patients were assigned to be perfused with an oxygenator with IP and IAF. Importantly, the integrated perfusion systems used in these patients were flushed with carbon dioxide (CO 2 ) prior to priming of the systems. In the group with CO 2 flush no spontaneous air release was observed in all cases and this was significantly different from the initial study with the group with the integrated device and IAF. This suggests that air spilling may be caused by residual air in the integrated device. In conclusion, integration of a blood pump may cause spontaneous release of large air bubbles (>500 µm) into the arterial line, despite the presence of an integrated arterial filter. CO 2 flushing of

Endovascular treatment of acute basilar artery occlusion: time to treatment is crucial

International Nuclear Information System (INIS)

Dorňák, T.; Herzig, R.; Kuliha, M.; Havlíček, R.; Školoudík, D.; Šaňák, D.; Köcher, M.; Procházka, V.; Lacman, J.; Charvát, F.; Krajina, A.

2015-01-01

Aim: To evaluate the safety and efficacy of multimodal endovascular treatment (EVT) of acute basilar artery occlusion (BAO), including bridging therapy [intravenous thrombolysis (IVT) with subsequent EVT], to compare particular EVT techniques and identify predictors of clinical outcome. Materials and methods: This retrospective, multi-centre study comprised 72 acute ischaemic stroke patients (51 males; mean age 59.1 ± 13.3 years) with radiologically confirmed BAO. The following data were collected: baseline characteristics, risk factors, pre-event antithrombotic treatment, neurological deficit at time of treatment, localization of occlusion, time to therapy, recanalization rate, post-treatment imaging findings. Thirty- and 90-day outcomes were evaluated using the modified Rankin scale with a good clinical outcome defined as 0–3 points. Results: Successful recanalization was achieved in 94.4% patients. Stepwise binary logistic regression analysis identified the presence of arterial hypertension (OR = 0.073 and OR = 0.067, respectively), National Institutes of Health Stroke Scale (NIHSS) at the time of treatment (OR = 0,829 and OR = 0.864, respectively), and time to treatment (OR = 0.556 and OR = 0.502, respectively) as significant independent predictors of 30- and 90-day clinical outcomes. Conclusion: Data from this multicentre study showed that multimodal EVT was an effective recanalization method in acute BAO. Bridging therapy shortens the time to treatment, which was identified as the only modifiable outcome predictor. - Highlights: • Various treatments are being used in recanalization of basilar artery occlusion. • Multimodal endovascular treatment is an effective recanalization method. • Time-to-treatment is the only modifiable outcome predictor. • Bridging therapy shortens time-to-treatment. • Arterial hypertension, neurologic deficit are associated with poor outcome

Is It Possible to Detect Activated Brown Adipose Tissue in Humans Using Single-Time-Point Infrared Thermography under Thermoneutral Conditions? Impact of BMI and Subcutaneous Adipose Tissue Thickness.

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Sergios Gatidis

Full Text Available To evaluate the feasibility to detect activated brown adipose tissue (BAT using single-time-point infrared thermography of the supraclavicular skin region under thermoneutral conditions. To this end, infrared thermography was compared with 18-F-FDG PET, the current reference standard for the detection of activated BAT.120 patients were enrolled in this study. After exclusion of 18 patients, 102 patients (44 female, 58 male, mean age 58±17 years were included for final analysis. All patients underwent a clinically indicated 18F-FDG-PET/CT examination. Immediately prior to tracer injection skin temperatures of the supraclavicular, presternal and jugular regions were measured using spatially resolved infrared thermography at room temperature. The presence of activated BAT was determined in PET by typical FDG uptake within the supraclavicular adipose tissue compartments. Local thickness of supraclavicular subcutaneous adipose tissue (SCAT was measured on CT. Measured skin temperatures were statistically correlated with the presence of activated BAT and anthropometric data.Activated BAT was detected in 9 of 102 patients (8.8%. Local skin temperature of the supraclavicular region was significantly higher in individuals with active BAT compared to individuals without active BAT. However, after statistical correction for the influence of BMI, no predictive value of activated BAT on skin temperature of the supraclavicular region could be observed. Supraclavicular skin temperature was significantly negatively correlated with supraclavicular SCAT thickness.We conclude that supraclavicular SCAT thickness influences supraclavicular skin temperature and thus makes a specific detection of activated BAT using single-time-point thermography difficult. Further studies are necessary to evaluate the possibility of BAT detection using alternative thermographic methods, e.g. dynamic thermography or MR-based thermometry taking into account BMI as a confounding factor.

A multiscale active structural model of the arterial wall accounting for smooth muscle dynamics.

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Coccarelli, Alberto; Edwards, David Hughes; Aggarwal, Ankush; Nithiarasu, Perumal; Parthimos, Dimitris

2018-02-01

Arterial wall dynamics arise from the synergy of passive mechano-elastic properties of the vascular tissue and the active contractile behaviour of smooth muscle cells (SMCs) that form the media layer of vessels. We have developed a computational framework that incorporates both these components to account for vascular responses to mechanical and pharmacological stimuli. To validate the proposed framework and demonstrate its potential for testing hypotheses on the pathogenesis of vascular disease, we have employed a number of pharmacological probes that modulate the arterial wall contractile machinery by selectively inhibiting a range of intracellular signalling pathways. Experimental probes used on ring segments from the rabbit central ear artery are: phenylephrine, a selective α 1-adrenergic receptor agonist that induces vasoconstriction; cyclopiazonic acid (CPA), a specific inhibitor of sarcoplasmic/endoplasmic reticulum Ca 2+ -ATPase; and ryanodine, a diterpenoid that modulates Ca 2+ release from the sarcoplasmic reticulum. These interventions were able to delineate the role of membrane versus intracellular signalling, previously identified as main factors in smooth muscle contraction and the generation of vessel tone. Each SMC was modelled by a system of nonlinear differential equations that account for intracellular ionic signalling, and in particular Ca 2+ dynamics. Cytosolic Ca 2+ concentrations formed the catalytic input to a cross-bridge kinetics model. Contractile output from these cellular components forms the input to the finite-element model of the arterial rings under isometric conditions that reproduces the experimental conditions. The model does not account for the role of the endothelium, as the nitric oxide production was suppressed by the action of L-NAME, and also due to the absence of shear stress on the arterial ring, as the experimental set-up did not involve flow. Simulations generated by the integrated model closely matched experimental

Vasodilatory effect and endothelial integrity in papaverine- and milrinone-treated human radial arteries.

Science.gov (United States)

Rudzinski, P; Wegrzyn, P; Lis, G J; Piatek, J; Konstanty-Kalandyk, J; Nosalski, R; Mikolajczyk, T; Jasinska, M; Pyka-Fosciak, G; Guzik, T; Litwin, J A; Korbut, R; Sadowski, J

2013-02-01

Prevention of the vasospasm is an important aspect of coronary artery bypass grafting (CABG) with the use of radial artery (RA) as the conduit. We compared the effect of two phosphodiesterase inhibitors papaverine and milrinone on vasodilation and endothelial integrity of human RA segments harvested from 20 CABG patients. Vasodilatory effect of the drugs were assessed by organ bath technique in RA rings precontracted with KCl and phenylephrine. Endothelial integrity was evaluated by CD34 immunofluorescence in frozen sections. Vasorelaxation induced by papaverine was significantly greater as compared to that induced by milrinone (90.47% ± 10.16% vs. 78.98% ± 19.56%, pmilrinone in the preservation of endothelial integrity (75.3% ± 12.9% vs. 51.8% ± 18.0%, pmilrinone for prevention of vasospasm in radial artery conduits used for CABG.

Central Artery Stiffness, Baroreflex Sensitivity, and Brain White Matter Neuronal Fiber Integrity in Older Adults

OpenAIRE

Tarumi, Takashi; de Jong, Daan L.K.; Zhu, David C.; Tseng, Benjamin Y.; Liu, Jie; Hill, Candace; Riley, Jonathan; Womack, Kyle B.; Kerwin, Diana R.; Lu, Hanzhang; Cullum, C. Munro; Zhang, Rong

2015-01-01

Cerebral hypoperfusion elevates the risk of brain white matter (WM) lesions and cognitive impairment. Central artery stiffness impairs baroreflex, which controls systemic arterial perfusion, and may deteriorate neuronal fiber integrity of brain WM. The purpose of this study was to examine the associations among brain WM neuronal fiber integrity, baroreflex sensitivity (BRS), and central artery stiffness in older adults. Fifty-four adults (65±6 years) with normal cognitive function or mild cog...

Time-driven activity-based costing of multivessel coronary artery bypass grafting across national boundaries to identify improvement opportunities: study protocol.

Science.gov (United States)

Erhun, F; Mistry, B; Platchek, T; Milstein, A; Narayanan, V G; Kaplan, R S

2015-08-25

Coronary artery bypass graft (CABG) surgery is a well-established, commonly performed treatment for coronary artery disease--a disease that affects over 10% of US adults and is a major cause of morbidity and mortality. In 2005, the mean cost for a CABG procedure among Medicare beneficiaries in the USA was $32, 201 ± $23,059. The same operation reportedly costs less than $2000 to produce in India. The goals of the proposed study are to (1) identify the difference in the costs incurred to perform CABG surgery by three Joint Commission accredited hospitals with reputations for high quality and efficiency and (2) characterise the opportunity to reduce the cost of performing CABG surgery. We use time-driven activity-based costing (TDABC) to quantify the hospitals' costs of producing elective, multivessel CABG. TDABC estimates the costs of a given clinical service by combining information about the process of patient care delivery (specifically, the time and quantity of labour and non-labour resources utilised to perform each activity) with the unit cost of each resource used to provide the care. Resource utilisation was estimated by constructing CABG process maps for each site based on observation of care and staff interviews. Unit costs were calculated as a capacity cost rate, measured as a $/min, for each resource consumed in CABG production. Multiplying together the unit costs and resource quantities and summing across all resources used will produce the average cost of CABG production at each site. We will conclude by conducting a variance analysis of labour costs to reveal opportunities to bend the cost curve for CABG production in the USA. All our methods were exempted from review by the Stanford Institutional Review Board. Results will be published in peer-reviewed journals and presented at scientific meetings. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Spontaneous coronary artery dissection and its association with heritable connective tissue disorders.

Science.gov (United States)

Henkin, Stanislav; Negrotto, Sara M; Tweet, Marysia S; Kirmani, Salman; Deyle, David R; Gulati, Rajiv; Olson, Timothy M; Hayes, Sharonne N

2016-06-01

Spontaneous coronary artery dissection (SCAD) is an under-recognised but important cause of myocardial infarction and sudden cardiac death. We sought to determine the role of medical and molecular genetic screening for connective tissue disorders in patients with SCAD. We performed a single-centre retrospective descriptive analysis of patients with spontaneous coronary artery disease who had undergone medical genetics evaluation 1984-2014 (n=116). The presence or absence of traits suggestive of heritable connective tissue disease was extracted. Genetic testing for connective tissue disorders and/or aortopathies, if performed, is also reported. Of the 116 patients (mean age 44.2 years, 94.8% women and 41.4% with non-coronary fibromuscular dysplasia (FMD)), 59 patients underwent genetic testing, of whom 3 (5.1%) received a diagnosis of connective tissue disorder: a 50-year-old man with Marfan syndrome; a 43-year-old woman with vascular Ehlers-Danlos syndrome and FMD; and a 45-year-old woman with vascular Ehlers-Danlos syndrome. An additional 12 patients (20.3%) had variants of unknown significance, none of which was thought to be a definite disease-causing mutation based on in silico analyses. Only a minority of patients with SCAD who undergo genetic evaluation have a likely pathogenic mutation identified on gene panel testing. Even fewer exhibit clinical features of connective tissue disorder. These findings underscore the need for further studies to elucidate the molecular mechanisms of SCAD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

The effects of 3-month atorvastatin therapy on arterial inflammation, calcification, abdominal adipose tissue and circulating biomarkers

Energy Technology Data Exchange (ETDEWEB)

Wu, Yen-Wen [National Taiwan University Hospital, Department of Internal Medicine, Taipei (China); National Taiwan University Hospital, Department of Nuclear Medicine, Taipei (China); Kao, Hsian-Li; Chen, Ming-Fong; Lin, Lian-Yu; Wang, Yi-Chih; Lin, Yen-Hung; Lin, Hung-Ju; Huang, Por-Jau [National Taiwan University Hospital, Department of Internal Medicine, Taipei (China); Huang, Chi-Lun [Tao-Yuan General Hospital, Department of Internal Medicine, Tao-Yuan (China); Tzen, Kai-Yuan; Yen, Ruoh-Fang [National Taiwan University Hospital, Department of Nuclear Medicine, Taipei (China); Chi, Yu-Chiao [National Taiwan University, Graduate Institute of Clinical Medicine, College of Medicine, Taipei (China); Yang, Wei-Shiung [National Taiwan University Hospital, Department of Internal Medicine, Taipei (China); National Taiwan University, Graduate Institute of Clinical Medicine, College of Medicine, Taipei (China)

2012-03-15

{sup 18}F-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT has the potential to track vascular inflammation and monitor therapeutic response. The purpose of this study was to determine the association between arterial inflammation, calcification and serological biomarkers in subjects with atherosclerosis, and to assess their therapeutic response to 12-week atorvastatin treatment. Forty-three statin-naive subjects with atherosclerosis received atorvastatin (40 mg/day) for 12 weeks and underwent {sup 18}F-FDG PET/CT, coronary calcification and abdominal adipose tissue volume measurements. A panel of serological biomarkers was analysed. Arterial inflammation was measured at seven arterial segments and normalized to venous FDG activity to produce target to background ratios (TBR). Thirty-four subjects without cardiovascular disease who repeated PET 1-4 years apart for routine health check-ups were retrospectively evaluated for comparison. The baseline mean TBR values in atherosclerotic patients were positively correlated with age (R = 0.36), body mass index (R = 0.54), abdominal visceral adipose tissue volume (R = 0.65), coronary calcification score (R = 0.40), levels of low-density lipoprotein cholesterol (R = 0.54), matrix metalloproteinase (MMP)-9 (R = 0.46) and fatty acid binding protein 4 (FABP4) (R = 0.67, all p < 0.05). The TBR as well as high-sensitivity C-reactive protein (hsCRP), E-selectin, MMP-9, monocyte chemotactic protein 1, FABP4 and follistatin values were reduced significantly after the 12-week atorvastatin treatment. The TBR reduction marginally correlated with changes in MMP-9 levels (R = 0.56, p = 0.05). The control group, whose median age was younger, by comparison had lower hsCRP and arterial TBR than the subjects with atherosclerosis (all p < 0.05), and moreover had a slight but insignificant increase in mean TBR at their 2.5{+-}0.8 year follow-up. The medium dose of atorvastatin over a 12-week period resulted in a significant

The effects of 3-month atorvastatin therapy on arterial inflammation, calcification, abdominal adipose tissue and circulating biomarkers

International Nuclear Information System (INIS)

Wu, Yen-Wen; Kao, Hsian-Li; Chen, Ming-Fong; Lin, Lian-Yu.; Wang, Yi-Chih; Lin, Yen-Hung; Lin, Hung-Ju; Huang, Por-Jau; Huang, Chi-Lun; Tzen, Kai-Yuan; Yen, Ruoh-Fang; Chi, Yu-Chiao; Yang, Wei-Shiung

2012-01-01

18 F-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT has the potential to track vascular inflammation and monitor therapeutic response. The purpose of this study was to determine the association between arterial inflammation, calcification and serological biomarkers in subjects with atherosclerosis, and to assess their therapeutic response to 12-week atorvastatin treatment. Forty-three statin-naive subjects with atherosclerosis received atorvastatin (40 mg/day) for 12 weeks and underwent 18 F-FDG PET/CT, coronary calcification and abdominal adipose tissue volume measurements. A panel of serological biomarkers was analysed. Arterial inflammation was measured at seven arterial segments and normalized to venous FDG activity to produce target to background ratios (TBR). Thirty-four subjects without cardiovascular disease who repeated PET 1-4 years apart for routine health check-ups were retrospectively evaluated for comparison. The baseline mean TBR values in atherosclerotic patients were positively correlated with age (R = 0.36), body mass index (R = 0.54), abdominal visceral adipose tissue volume (R = 0.65), coronary calcification score (R = 0.40), levels of low-density lipoprotein cholesterol (R = 0.54), matrix metalloproteinase (MMP)-9 (R = 0.46) and fatty acid binding protein 4 (FABP4) (R = 0.67, all p < 0.05). The TBR as well as high-sensitivity C-reactive protein (hsCRP), E-selectin, MMP-9, monocyte chemotactic protein 1, FABP4 and follistatin values were reduced significantly after the 12-week atorvastatin treatment. The TBR reduction marginally correlated with changes in MMP-9 levels (R = 0.56, p = 0.05). The control group, whose median age was younger, by comparison had lower hsCRP and arterial TBR than the subjects with atherosclerosis (all p < 0.05), and moreover had a slight but insignificant increase in mean TBR at their 2.5±0.8 year follow-up. The medium dose of atorvastatin over a 12-week period resulted in a significant reduction of

A 3D bioprinting system to produce human-scale tissue constructs with structural integrity.

Science.gov (United States)

Kang, Hyun-Wook; Lee, Sang Jin; Ko, In Kap; Kengla, Carlos; Yoo, James J; Atala, Anthony

2016-03-01

A challenge for tissue engineering is producing three-dimensional (3D), vascularized cellular constructs of clinically relevant size, shape and structural integrity. We present an integrated tissue-organ printer (ITOP) that can fabricate stable, human-scale tissue constructs of any shape. Mechanical stability is achieved by printing cell-laden hydrogels together with biodegradable polymers in integrated patterns and anchored on sacrificial hydrogels. The correct shape of the tissue construct is achieved by representing clinical imaging data as a computer model of the anatomical defect and translating the model into a program that controls the motions of the printer nozzles, which dispense cells to discrete locations. The incorporation of microchannels into the tissue constructs facilitates diffusion of nutrients to printed cells, thereby overcoming the diffusion limit of 100-200 μm for cell survival in engineered tissues. We demonstrate capabilities of the ITOP by fabricating mandible and calvarial bone, cartilage and skeletal muscle. Future development of the ITOP is being directed to the production of tissues for human applications and to the building of more complex tissues and solid organs.

Epicardial adipose tissue and pericoronary fat thickness measured with 64-multidetector computed tomography: potential predictors of the severity of coronary artery disease

Directory of Open Access Journals (Sweden)

Muhammed Bora Demircelik

2014-06-01

Full Text Available OBJECTIVE:The aim of the present study was to investigate the relationship between pericoronary fat and the severity and extent of atherosclerosis, quantified using 64-multidetector computed tomography, in patients with suspected coronary artery disease.METHODS:The study population consisted of 131 patients who were clinically referred for noninvasive multislice computed tomography coronary angiography for the evaluation of coronary artery disease. Patients were classified as follows: no atherosclerosis, Group 1; nonobstructive atherosclerosis (luminal narrowing <50% in diameter, Group 2; and obstructive atherosclerosis (luminal narrowing ≥50% in a single vessel or obstructive atherosclerosis in the left main coronary artery and/or multiple vessels, Group 3. Epicardial adipose tissue was defined as the adipose tissue between the surface of the heart and the visceral layer of the pericardium (visceral epicardium. Epicardial adipose tissue thickness (mm was determined in the right ventricular anterior free wall. The mean thickness of the pericoronary fat surrounding the three coronary arteries was used for the analyses.RESULTS:The average thickness over all three regions was 13.2 ± 2.1 mm. The pericoronary fat thickness was significantly increased in Group 3 compared with Groups 2 and 1. The epicardial adipose tissue thickness was significantly increased in Group 3 compared with Groups 2 and 1. A receiver operating characteristic curve for obstructive coronary artery disease was assessed to verify the optimum cut-off point for pericoronary fat thickness, which was 13.8 mm. A receiver operating characteristic curve for obstructive coronary artery disease was also assessed to verify the optimum cut-off point for epicardial adipose tissue, which was 6.8 cm.CONCLUSION:We showed that the epicardial adipose tissue and pericoronary fat thickness scores were higher in patients with obstructive coronary artery diseases.

Epicardial adipose tissue and pericoronary fat thickness measured with 64-multidetector computed tomography: potential predictors of the severity of coronary artery disease

Energy Technology Data Exchange (ETDEWEB)

Demircelik, Muhammed Bora; Gurel, Ozgul Malcok; Selcoki, Yusuf; Atar, Inci Asli; Eryonucu, Beyhan, E-mail: drdemircelik@yahoo.com [Turgut Ozal Univercity, Department of Cardiology, Ankara (Turkey); Bozkurt, Alper; Akin, Kayihan [Turgut Ozal Univercity, Department of Radiology, Ankara (Turkey); Yilmaz, Omer Caglar [Ankara Occupational Diseases Hospital, Department of Cardiology, Ankara (Turkey)

2014-06-15

Objective: the aim of the present study was to investigate the relationship between pericoronary fat and the severity and extent of atherosclerosis, quantified using 64-multidetector computed tomography, in patients with suspected coronary artery disease. Methods: the study population consisted of 131 patients who were clinically referred for noninvasive multislice computed tomography coronary angiography for the evaluation of coronary artery disease. Patients were classified as follows: no atherosclerosis, Group 1; nonobstructive atherosclerosis (luminal narrowing < 50% in diameter), Group 2; and obstructive atherosclerosis (luminal narrowing ≧ 50%) in a single vessel or obstructive atherosclerosis in the left main coronary artery and/or multiple vessels, Group 3. Epicardial adipose tissue was defined as the adipose tissue between the surface of the heart and the visceral layer of the pericardium (visceral epicardium). Epicardial adipose tissue thickness (mm) was determined in the right ventricular anterior free wall. The mean thickness of the pericoronary fat surrounding the three coronary arteries was used for the analyses. Results: the average thickness over all three regions was 13.2 ± 2.1 mm. The pericoronary fat thickness was significantly increased in Group 3 compared with Groups 2 and 1. The epicardial adipose tissue thickness was significantly increased in Group 3 compared with Groups 2 and 1. A receiver operating characteristic curve for obstructive coronary artery disease was assessed to verify the optimum cut-off point for pericoronary fat thickness, which was 13.8 mm. A receiver operating characteristic curve for obstructive coronary artery disease was also assessed to verify the optimum cut-off point for epicardial adipose tissue, which was 6.8 cm. Conclusion: we showed that the epicardial adipose tissue and pericoronary fat thickness scores were higher in patients with obstructive coronary artery diseases. (author)

Epicardial adipose tissue and pericoronary fat thickness measured with 64-multidetector computed tomography: potential predictors of the severity of coronary artery disease

International Nuclear Information System (INIS)

Demircelik, Muhammed Bora; Gurel, Ozgul Malcok; Selcoki, Yusuf; Atar, Inci Asli; Eryonucu, Beyhan; Bozkurt, Alper; Akin, Kayihan; Yilmaz, Omer Caglar

2014-01-01

Objective: the aim of the present study was to investigate the relationship between pericoronary fat and the severity and extent of atherosclerosis, quantified using 64-multidetector computed tomography, in patients with suspected coronary artery disease. Methods: the study population consisted of 131 patients who were clinically referred for noninvasive multislice computed tomography coronary angiography for the evaluation of coronary artery disease. Patients were classified as follows: no atherosclerosis, Group 1; nonobstructive atherosclerosis (luminal narrowing < 50% in diameter), Group 2; and obstructive atherosclerosis (luminal narrowing ≧ 50%) in a single vessel or obstructive atherosclerosis in the left main coronary artery and/or multiple vessels, Group 3. Epicardial adipose tissue was defined as the adipose tissue between the surface of the heart and the visceral layer of the pericardium (visceral epicardium). Epicardial adipose tissue thickness (mm) was determined in the right ventricular anterior free wall. The mean thickness of the pericoronary fat surrounding the three coronary arteries was used for the analyses. Results: the average thickness over all three regions was 13.2 ± 2.1 mm. The pericoronary fat thickness was significantly increased in Group 3 compared with Groups 2 and 1. The epicardial adipose tissue thickness was significantly increased in Group 3 compared with Groups 2 and 1. A receiver operating characteristic curve for obstructive coronary artery disease was assessed to verify the optimum cut-off point for pericoronary fat thickness, which was 13.8 mm. A receiver operating characteristic curve for obstructive coronary artery disease was also assessed to verify the optimum cut-off point for epicardial adipose tissue, which was 6.8 cm. Conclusion: we showed that the epicardial adipose tissue and pericoronary fat thickness scores were higher in patients with obstructive coronary artery diseases. (author)

Characterization of human arterial tissue affected by atherosclerosis using multimodal nonlinear optical microscopy

Science.gov (United States)

Baria, Enrico; Cicchi, Riccardo; Rotellini, Matteo; Nesi, Gabriella; Massi, Daniela; Pavone, Francesco S.

2016-03-01

Atherosclerosis is a widespread cardiovascular disease caused by the deposition of lipids (such as cholesterol and triglycerides) on the inner arterial wall. The rupture of an atherosclerotic plaque, resulting in a thrombus, is one of the leading causes of death in the Western World. Preventive assessment of plaque vulnerability is therefore extremely important and can be performed by studying collagen organization and lipid composition in atherosclerotic arterial tissues. Routinely used diagnostic methods, such as histopathological examination, are limited to morphological analysis of the examined tissues, whereas an exhaustive characterization requires immune-histochemical examination and a morpho-functional approach. Instead, a label-free and non-invasive alternative is provided by nonlinear microscopy. In this study, we combined SHG and FLIM microscopy in order to characterize collagen organization and lipids in human carotid ex vivo tissues affected by atherosclerosis. SHG and TPF images, acquired from different regions within atherosclerotic plaques, were processed through image pattern analysis methods (FFT, GLCM). The resulting information on collagen and cholesterol distribution and anisotropy, combined with collagen and lipids fluorescence lifetime measured from FLIM images, allowed characterization of carotid samples and discrimination of different tissue regions. The presented method can be applied for automated classification of atherosclerotic lesions and plaque vulnerability. Moreover, it lays the foundation for a potential in vivo diagnostic tool to be used in clinical setting.

Spatial differences of cellular origins and in vivo hypoxia modify contractile properties of pulmonary artery smooth muscle cells: lessons for arterial tissue engineering.

Science.gov (United States)

Hall, S M; Soueid, A; Smith, T; Brown, R A; Haworth, S G; Mudera, V

2007-01-01

Tissue engineering of functional arteries is challenging. Within the pulmonary artery wall, smooth muscle cells (PASMCs) have site-specific developmental and functional phenotypes, reflecting differing contractile roles. The force generated by PASMCs isolated from the inner 25% and outer 50% of the media of intrapulmonary elastic arteries from five normal and eight chronically hypoxic (hypertensive) 14 day-old piglets was quantified in a three-dimensional (3D) collagen construct, using a culture force monitor. Outer medial PASMCs from normal piglets exerted more force (528 +/- 50 dynes) than those of hypoxic piglets (177 +/- 42 dynes; p engineering of major blood vessels.

Acute Effects of Lateral Thigh Foam Rolling on Arterial Tissue Perfusion Determined by Spectral Doppler and Power Doppler Ultrasound.

Science.gov (United States)

Hotfiel, Thilo; Swoboda, Bernd; Krinner, Sebastian; Grim, Casper; Engelhardt, Martin; Uder, Michael; Heiss, Rafael U

2017-04-01

Hotfiel, T, Swoboda, B, Krinner, S, Grim, C, Engelhardt, M, Uder, M, and Heiss, R. Acute effects of lateral thigh foam rolling on arterial tissue perfusion determined by spectral Doppler and power Doppler ultrasound. J Strength Cond Res 31(4): 893-900, 2017-Foam rolling has been developed as a popular intervention in training and rehabilitation. However, evidence on its effects on the cellular and physiological level is lacking. The aim of this study was to assess the effect of foam rolling on arterial blood flow of the lateral thigh. Twenty-one healthy participants (age, 25 ± 2 years; height, 177 ± 9 cm; body weight, 74 ± 9 kg) were recruited from the medical and sports faculty. Arterial tissue perfusion was determined by spectral Doppler and power Doppler ultrasound, represented as peak flow (Vmax), time average velocity maximum (TAMx), time average velocity mean (TAMn), and resistive index (RI), and with semiquantitative grading that was assessed by 4 blindfolded investigators. Measurement values were assessed under resting conditions and twice after foam rolling exercises of the lateral thigh (0 and 30 minutes after intervention). The trochanteric region, mid portion, and distal tibial insertion of the lateral thigh were representative for data analysis. Arterial blood flow of the lateral thigh increased significantly after foam rolling exercises compared with baseline (p ≤ 0.05). We detected a relative increase in Vmax of 73.6% (0 minutes) and 52.7% (30 minutes) (p power Doppler scores at all portions revealed increased average grading of 1.96 after intervention and 2.04 after 30 minutes compared with 0.75 at baseline. Our results may contribute to the understanding of local physiological reactions to self-myofascial release.

Epicardial adipose tissue as a predictor of coronary artery disease in asymptomatic subjects.

Science.gov (United States)

Bachar, Gil N; Dicker, Dror; Kornowski, Ran; Atar, Eli

2012-08-15

This study sought to elucidate the relation between epicardial adipose tissue (EAT) thickness measured by multidetector computed tomography and presence of coronary artery atherosclerosis. Recent studies have suggested that fat disposition in visceral organs and epicardial tissue could serve as a predictor of coronary artery disease (CAD). The sample included 190 asymptomatic subjects with ≥ 1 cardiovascular risk factor who were referred for cardiac computed tomographic angiography. Body mass index, blood pressure, fasting glucose level, and lipid profile were measured. Multidetector computed tomographic results were analyzed for atherosclerosis burden, calcium Agatston score, and EAT thickness: mean EAT values were 3.54 ± 1.59 mm in patients with atherosclerosis and 1.85 ± 1.28 mm in patients without atherosclerosis (p 50% diameter) coronary artery stenosis. There was a significant difference in EAT values between patients with and without metabolic syndrome (2.58 ± 1.63 vs 2.04 ± 1.46 mm, p 400 and <400 (3.38 ± 1.58 vs 2.02 ± 1.42 mm, p <0.0001). In conclusion, asymptomatic patients with CAD have significantly more EAT than patients without CAD. An EAT thickness of 2.4 mm is the optimal cutoff for prediction of presence of significant CAD. Copyright © 2012 Elsevier Inc. All rights reserved.

Catalase activity prevents exercise-induced up-regulation of vasoprotective proteins in venous tissue

OpenAIRE

Dao, Vu Thao-Vi; Floeren, Melanie; Kumpf, Stephanie; Both, Charlotte; Peter, B?rbel; Balz, Vera; Suvorava, Tatsiana; Kojda, Georg

2011-01-01

Abstract Physical activity induces favourable changes of arterial gene expression and protein activity, although little is known about its effect in venous tissue. Although our understanding of the initiating molecular signals is still incomplete, increased expression of endothelial nitric oxide synthase (eNOS) is considered a key event. This study sought to investigate the effects of two different training protocols on the expression of eNOS and extracellular superoxide dismutase (ecSOD) in ...

Target and Tissue Selectivity Prediction by Integrated Mechanistic Pharmacokinetic-Target Binding and Quantitative Structure Activity Modeling.

Science.gov (United States)

Vlot, Anna H C; de Witte, Wilhelmus E A; Danhof, Meindert; van der Graaf, Piet H; van Westen, Gerard J P; de Lange, Elizabeth C M

2017-12-04

Selectivity is an important attribute of effective and safe drugs, and prediction of in vivo target and tissue selectivity would likely improve drug development success rates. However, a lack of understanding of the underlying (pharmacological) mechanisms and availability of directly applicable predictive methods complicates the prediction of selectivity. We explore the value of combining physiologically based pharmacokinetic (PBPK) modeling with quantitative structure-activity relationship (QSAR) modeling to predict the influence of the target dissociation constant (K D ) and the target dissociation rate constant on target and tissue selectivity. The K D values of CB1 ligands in the ChEMBL database are predicted by QSAR random forest (RF) modeling for the CB1 receptor and known off-targets (TRPV1, mGlu5, 5-HT1a). Of these CB1 ligands, rimonabant, CP-55940, and Δ 8 -tetrahydrocanabinol, one of the active ingredients of cannabis, were selected for simulations of target occupancy for CB1, TRPV1, mGlu5, and 5-HT1a in three brain regions, to illustrate the principles of the combined PBPK-QSAR modeling. Our combined PBPK and target binding modeling demonstrated that the optimal values of the K D and k off for target and tissue selectivity were dependent on target concentration and tissue distribution kinetics. Interestingly, if the target concentration is high and the perfusion of the target site is low, the optimal K D value is often not the lowest K D value, suggesting that optimization towards high drug-target affinity can decrease the benefit-risk ratio. The presented integrative structure-pharmacokinetic-pharmacodynamic modeling provides an improved understanding of tissue and target selectivity.

Dynamic CT brain scanning in the haemodynamic evaluation of cerebral arterial occlusive disease

International Nuclear Information System (INIS)

Davis, S.M.; Melbourne Univ.; Tress, B.M.; Hopper, J.L.; Rossiter, S.C.; Kaye, A.H.

1987-01-01

Dynamic cerebral CT scanning (DCT) was used to quantitatively analyse the haemodynamic effects of extracranial and intracranial arterial occlusive lesions in 17 patients with TIA's or minor cerebral infarcts. Using DCT and gamma variate curve fitting, mean transit times were determined for the terminal internal carotid arteries, middle cerebral arteries and middle cerebral-supplied Sylvian cortex at the level of the Circle of Willis. Six patients were studied sequentially, four before and after transcranial bypass surgery. No arterial or tissue delays were found in patients without haemodynamic arterial lesions or cortical infarcts. Seven of nine patients with haemodynamic, extracranial carotid lesions showed ipsilateral delays in arterial or tissue transit times. Tissue delays usually correlated with CT or clinical evidence of infarction. Improved haemodynamics in patients re-studied correlated with the effects of surgery or clinical recovery. DCT has several important limitations but has the potential to provide additional haemodynamic information about the cerebral circulation in selected patients with cerebral arterial occlusive disease. (orig.)

Optical coherence tomography detection of shear wave propagation in inhomogeneous tissue equivalent phantoms and ex-vivo carotid artery samples

Science.gov (United States)

Razani, Marjan; Luk, Timothy W.H.; Mariampillai, Adrian; Siegler, Peter; Kiehl, Tim-Rasmus; Kolios, Michael C.; Yang, Victor X.D.

2014-01-01

In this work, we explored the potential of measuring shear wave propagation using optical coherence elastography (OCE) in an inhomogeneous phantom and carotid artery samples based on a swept-source optical coherence tomography (OCT) system. Shear waves were generated using a piezoelectric transducer transmitting sine-wave bursts of 400 μs duration, applying acoustic radiation force (ARF) to inhomogeneous phantoms and carotid artery samples, synchronized with a swept-source OCT (SS-OCT) imaging system. The phantoms were composed of gelatin and titanium dioxide whereas the carotid artery samples were embedded in gel. Differential OCT phase maps, measured with and without the ARF, detected the microscopic displacement generated by shear wave propagation in these phantoms and samples of different stiffness. We present the technique for calculating tissue mechanical properties by propagating shear waves in inhomogeneous tissue equivalent phantoms and carotid artery samples using the ARF of an ultrasound transducer, and measuring the shear wave speed and its associated properties in the different layers with OCT phase maps. This method lays the foundation for future in-vitro and in-vivo studies of mechanical property measurements of biological tissues such as vascular tissues, where normal and pathological structures may exhibit significant contrast in the shear modulus. PMID:24688822

Flow-Through Free Fibula Osteocutaneous Flap in Reconstruction of Tibial Bone, Soft Tissue, and Main Artery Segmental Defects.

Science.gov (United States)

Li, Zonghuan; Yu, Aixi; Qi, Baiwen; Pan, Zhenyu; Ding, Junhui

2017-08-01

The aim of this report was to present the use of flow-through free fibula osteocutaneous flap for the repair of complex tibial bone, soft tissue, and main artery segmental defects. Five patients with bone, soft tissue, and segmental anterior tibial artery defects were included. The lengths of injured tibial bones ranged from 4 to 7 cm. The sizes of impaired soft tissues were between 9 × 4 and 15 × 6 cm. The lengths of defect of anterior tibial artery segments ranged from 6 to 10 cm. Two patients had distal limb perfusion problems. Flow-through free fibula osteocutaneous flap was performed for all 5 patients. Patients were followed for 12 to 18 months. All wounds healed after 1-stage operation, and all flow-through flaps survived. The distal perfusion after vascular repair was normal in all patients. Superficial necrosis of flap edge was noted in 1 case. After the local debridement and partial thickness skin graft, the flap healed uneventfully, and the surgical operation did not increase injury to the donor site. Satisfactory bone union was achieved in all patients in 2 to 4 months postoperation. Enlargement of fibula graft was observed during follow-up from 12 to 18 months. The functions of adjacent joints were recovered, and all patients were able to walk normally. Flow-through free fibula osteocutaneous flap was shown to be an effective and efficient technique for repairing composite tibial bone, soft tissue, and main artery segmental defects. This 1-stage operation should be useful in clinical practice for the treatment of complex bone, soft tissue, and vessel defects.

Tissue Doppler echocardiography improves the diagnosis of coronary artery stenosis in stable angina pectoris

DEFF Research Database (Denmark)

Hoffmann, Soren; Jensen, Jan Skov; Iversen, Allan Zeeberg

2012-01-01

Aim To determine if colour tissue Doppler imaging (TDI) performed at rest in patients with suspected stable angina pectoris (SAP) is able to predict the presence of significant coronary artery disease (CAD). METHODS AND RESULTS: This study comprises 296 consecutive patients with clinically...... by colour TDI at six mitral annular sites and averaged to provide global estimates. Duke score (DS), including ST depression, chest pain, and exercise capacity, was used as the outcome of the exercise ECG. Patients with an area stenosis of ≥70% in at least one epicardial coronary artery were categorized...

Resistin Enhances Inflammatory Cytokine Production in Coronary Artery Tissues by Activating the NF-κB Signaling

Directory of Open Access Journals (Sweden)

Fang Gao

2016-01-01

Full Text Available Purpose. Kawasaki disease (KD is a systemic vasculitis and is a leading cause of coronary artery lesions (CALs in childhood. Our previous study has shown higher levels of serum Resistin in KD patients with coronary aneurysm. This study aimed at examining the association of Resistin with inflammatory cytokine expression in mouse model of coronary arteritis and determining the potential mechanisms. Methods. C57BL/6 mice were injected with Lactobacillus cell wall extract (LCWE to induce coronary arteritis. The relative levels of Resistin, TNF-α, IL-1β, and MMP-9 expression and inflammatory infiltrates in the coronary arteries were determined longitudinally by quantitative RT-PCR, ELISA, and histology. The effect of TLR4 and NF-κB activation on Resistin-induced TNF-α and IL-1β expression in human coronary artery endothelium cells (HCAECs was examined by quantitative RT-PCR. Results. Higher levels of Resistin, TNF-α, IL-1β, and MMP-9 expression were associated with the degrees of inflammatory infiltrates in the coronary artery walls of the LCWE-injected mice. Resistin enhanced TNF-α and IL-1β expression in HCAECs at 18 or 24 hours after stimulation. Pretreatment with anti-TLR4 attenuated Resistin-enhanced IL-1β, but not TNF-α, expression and pretreatment with parthenolide or QNZ demolished Resistin-enhanced TNF-α expression in HACECs. Pretreatment with parthenolide, but not QNZ, blocked Resistin-enhanced IL-1β expression in HCAECs. Conclusion. Resistin may enhance inflammation by cross-talking with TLR4/NF-κB signaling during the development of coronary arteritis in mice.

Human active X-specific DNA methylation events showing stability across time and tissues

Science.gov (United States)

Joo, Jihoon Eric; Novakovic, Boris; Cruickshank, Mark; Doyle, Lex W; Craig, Jeffrey M; Saffery, Richard

2014-01-01

The phenomenon of X chromosome inactivation in female mammals is well characterised and remains the archetypal example of dosage compensation via monoallelic expression. The temporal series of events that culminates in inactive X-specific gene silencing by DNA methylation has revealed a ‘patchwork' of gene inactivation along the chromosome, with approximately 15% of genes escaping. Such genes are therefore potentially subject to sex-specific imbalance between males and females. Aside from XIST, the non-coding RNA on the X chromosome destined to be inactivated, very little is known about the extent of loci that may be selectively silenced on the active X chromosome (Xa). Using longitudinal array-based DNA methylation profiling of two human tissues, we have identified specific and widespread active X-specific DNA methylation showing stability over time and across tissues of disparate origin. Our panel of X-chromosome loci subject to methylation on Xa reflects a potentially novel mechanism for controlling female-specific X inactivation and sex-specific dimorphisms in humans. Further work is needed to investigate these phenomena. PMID:24713664

Proteome Analysis of Human Arterial Tissue Discloses Associations Between the Vascular Content of Small Leucine-Rich Repeat Proteoglycans and Pulse Wave Velocity

DEFF Research Database (Denmark)

Lyck Hansen, Maria; Beck, Hans Christian; Irmukhamedov, Akhmadjon

2015-01-01

OBJECTIVES: We hypothesized that arterial stiffness is associated with changes in the arterial protein profile, particularly of extracellular matrix components. We aimed at determining differentially expressed proteins by quantitative proteome analysis in arterial tissue from patients with differ......OBJECTIVES: We hypothesized that arterial stiffness is associated with changes in the arterial protein profile, particularly of extracellular matrix components. We aimed at determining differentially expressed proteins by quantitative proteome analysis in arterial tissue from patients...... with different degrees of arterial stiffness. APPROACH AND RESULTS: Arterial stiffness, assessed by carotid-femoral pulse wave velocity (PWV), central blood pressure and augmentation index by pulse wave analysis were measured the day before surgery in a group of patients undergoing coronary artery bypass...... grafting. Protein extracts of well-defined, homogenous, nonatherosclerotic individual samples of the left mammary artery from 10 of these patients with high PWV and 9 with low PWV were compared by quantitative proteome analysis, using tandem mass tag labeling and nano-liquid chromatography mass...

Repeated Intra-Arterial Thrombectomy within 72 Hours in a Patient with a Clear Contraindication for Intravenous Thrombolysis

Directory of Open Access Journals (Sweden)

Mona Laible

2015-01-01

Full Text Available Introduction. Treating patients with acute ischemic stroke, proximal arterial vessel occlusion, and absolute contraindication for administering intravenous recombinant tissue plasminogen activator (rtPA poses a therapeutic challenge. Intra-arterial thrombectomy constitutes an alternative treatment option. Materials and Methods. We report a case of a 57-year-old patient with concomitant gastric adenocarcinoma, who received three intra-arterial thrombectomies in 72 hours due to repeated occlusion of the left medial cerebral artery (MCA. Findings. Intra-arterial recanalization of the left medial cerebral artery was performed three times with initially good success. However, two days later, the right medial cerebral artery became occluded. Owing to the overall poor prognosis at that time and knowing the wishes of the patient, we decided not to perform another intra-arterial recanalization procedure. Conclusion. To our knowledge, this is the first case illustrating the use of repeated intra-arterial recanalization in early reocclusion of intracranial vessels.

Study of the expression for apoptosis factors of thyroid cells after arterial embolization to treat hyperthyroidism caused by Graved' disease

International Nuclear Information System (INIS)

Zhao Wei; Yi Genfa; Hu Jihong; Xiang Shutian; Jiang Yongneng; Li Liyuan; Hu Zhengqin; Yang Huiying; Li Hong; Shen Lijuan; Zhang Huaxian

2007-01-01

Objective: To study the expressions of Fas, FasL, Bax,Bcl-2 and P53 in thyroid tissue and to analyzis (Semi-quantitative analysis)the relation between change of apoptosis in thyroid tissues and clinical therapeutic effect after thyroid arterial embolization in treating hyperthyroidism caused by Graves' disease with observation of apoptosis for 3 years. Methods: 15 patients undergone core needle biopsy of the thyroid gland were divided into three groups according to the amount of time elapsed after thyroid arterial embolization: A group, before thyroid arterial embolization, B group, 1 year group (including 7-day subgroup, 3-month subgroup, 6-month subgroup) and C group, 1 year subgroup and mom than 1 year subgroup after arterial embolization. Results: (1) After embolisation, 15 patients' symptoms and signs of hyperthyroidism disappeared or improved greatly with 9 long term released and 6 improved with small amount of ATD maintenance. (2) The positive staining of Fas and FasL located in endochylema and cell-membrane of thyroid tissue from patients treated with transcathter arterial embolization were higher than those not treated with transcathter arterial embolization (P 0.05). (4) The positive cell and the staining of P53 in thyroid tissue had significant difference before and after thyroid arterial embolization (P<0.05). Conclusions: The extra-expression and the increased expression of Fas, FasL, Bax, P53 in thyroid tissue of patient with GD treated by thyroid arterial embolization are correlated with the effects of interventional therapy. (authors)

Time-resolved MR angiography of the renal artery: morphology and perfusion

International Nuclear Information System (INIS)

Krause, U.J.; Pabst, T.; Koestler, H.; Helbig, C.; Kenn, W.; Hahn, D.

2002-01-01

Purpose: To prove the hypothesis that renal artery stenosis and changes in renal perfusion can be detected with contrast-enhanced time-resolved MR angiography in a single examination. Material and Methods: In 71 patients, 137 renal arteries and 14 accessory renal arteries were studied. The examinations were performed on a 1.5 T system. A T 1 -weighted gradient echo sequence with a temporal resolution of 7 s was used. Single dose of contrast material (0.1 mmol/kg Gd-DTPA) was injected with a power injector with a flow rate of 2 ml/s. Criterion for the assessment of renal perfusion was the slope ratio of the signal intensity time curve in both kidneys. Results: Forty renal artery stenoses and one occlusion of a renal artery were detected. In 48 kidneys (35%) segmental arteries were evaluated. The accuracy of the slope ratio (limit value 0.75) concerning the detection of unilateral renal artery stenosis was 92.6% (sensitivity 75%, specificity 95.7%). Conclusion: Time-resolved MR angiography can detect changes in renal perfusion in patients with unilateral renal artery stenosis. (orig.) [de

Estimating the arterial input function from dynamic contrast-enhanced MRI data with compensation for flow enhancement (II): Applications in spine diagnostics and assessment of crohn's disease

NARCIS (Netherlands)

van Schie, Jeroen J. N.; Lavini, Cristina; van Vliet, Lucas J.; Kramer, Gem; Pieters-van den Bos, Indra; Marcus, J. T.; Stoker, Jaap; Vos, Frans M.

2017-01-01

Pharmacokinetic (PK) models can describe microvascular density and integrity. An essential component of PK models is the arterial input function (AIF) representing the time-dependent concentration of contrast agent (CA) in the blood plasma supplied to a tissue. To evaluate a novel method for

Controlled destruction and temperature distributions in biological tissues subjected to monoactive electrocoagulation.

Science.gov (United States)

Erez, A; Shitzer, A

1980-02-01

An analysis of the temperature fields developed in a biological tissue undergoing a monoactive electrical coagulating process is presented, including thermal recovery following prolonged heating. The analysis is performed for the passage of alternating current and assumes a homogeneous and isotropic tissue model which is uniformly perfused by blood at arterial temperature. Solution for the one-dimensional spherical geometry is obtained by a Laplace transform and numerical integrations. Results obtained indicate the major role which blood perfusion plays in determining the effects of the coagulating process; tissue temperatures and depth of destruction are drastically reduced as blood perfusion increases. Metabolic heat generation rate is found to have negligible effects on tissue temperatures whereas electrode thermal inertia affects temperature levels appreciably. However, electrodes employed in practice would have a low thermal inertia which might be regarded as zero for all practical purposes. It is also found that the depth of tissue destruction is almost directly proportional to the electrical power and duration of application. To avoid excessively high temperatures and charring, it would be advantageous to reduce power and increase the time of application. Results of this study should be regarded as a first approximation to the rather complex phenomena associated with electrocoagulation. They may, nevertheless, serve as preliminary guidelines to practicing surgeons applying this technique.

Diagnostic pathway of integrated SPECT/CT for coronary artery disease

International Nuclear Information System (INIS)

Slart, Riemer H.J.A.; Tio, Rene A.; Zijlstra, Felix; Dierckx, Rudi A.

2009-01-01

Treatment strategy in patients with suspected coronary artery disease (CAD) is driven by symptomatology in combination with diagnostic evaluation of the extent and/or severity of atherosclerosis in the coronary arteries and ischemia in the myocardium, i.e., the anatomic and functional correlates of CAD. Whereas multislice row computed tomography (MSCT) has the advantage of detecting coronary atherosclerosis at its earliest stages, thereby allowing initiation of appropriate therapeutic measures well before development of obstructive CAD, myocardial perfusion imaging (MPI) SPECT can clarify the hemodynamic consequences of the anatomic findings on MSCT based on a functional assessment of myocardial blood flow. There is a lack of correlation between coronary artery calcium (CAC), coronary artery stenosis, and MPI SPECT. Therefore CAC scoring and stress MPI should be thus considered complementary approaches rather than exclusionary in the evaluation of the patient at risk for CAD. The integration of anatomic and functional information may provide additional information for the clinician by the improved risk stratification and diagnostic accuracy of integrated techniques. The majority of previous studies are based on a sequential flowchart, starting with either SPECT or CAC scoring that finally directs the therapeutic strategy. Patients at low risk for CAD can be selected for primary prevention, and patients at high risk for CAD can be directly selected for coronary angiography (CAG). The remaining group of patients at intermediate risk for CAD can be substratified into lower- and higher-risk categories based on the presence or absence of stress-induced ischemia on MPI SPECT and CAC scoring. An integration of SPECT and CAC as a starting point for CAD detection in symptomatic patients at intermediate risk for CAD may facilitate a tailored diagnostic as well as therapeutic approach. Finally, using SPECT/CT, MPI SPECT, and CAC findings may be completed with CT angiography

Subclavian artery dissection during catheterization in a patient after irradiation

International Nuclear Information System (INIS)

Kanazawa, Susumu; Hiraki, Yoshio; Fujie, Shunji; Sato, Nobuo.

1997-01-01

A 47-year-old woman with right breast cancer underwent partial mastectomy and had irradiations to the primary and metastatic sites, including the left supraclavicular region. During catheterization of the left internal mammary artery for arterial infusion therapy, the patient developed an iatrogenic dissection and subsequent occlusion of the left subclavian artery. Arterial infusion of tissue plasminogen activator into the artery resulted in recanalization and improvement of clinical signs and symptoms. (author)

Effect of electrocautery on endothelial integrity of the internal thoracic artery: ultrastructural analysis with transmission electron microscopy.

Science.gov (United States)

Onan, Burak; Yeniterzi, Mehmet; Onan, Ismihan Selen; Ersoy, Burak; Gonca, Suheyla; Gelenli, Elif; Solakoglu, Seyhun; Bakir, Ihsan

2014-10-01

The internal thoracic artery (ITA) is typically harvested from the chest wall by means of conventional electrocautery. We investigated the effects of electrocautery on endothelial-cell and vessel-wall morphology at the ultrastructural level during ITA harvesting. Internal thoracic artery specimens from 20 patients who underwent elective coronary artery bypass grafting were investigated in 2 groups. The ITA grafts were sharply dissected with use of a scalpel and clips in the control group (n=10) and were harvested by means of electrocautery in the study group (n=10). Each sample was evaluated for intimal, elastic-tissue, muscular-layer, and adventitial changes. Free flow was measured intraoperatively. Light microscopic examinations were performed after hematoxylin-eosin and Masson's trichrome staining. Transmission electron microscopy was used to evaluate ultrastructural changes in the endothelial cells and vessel walls of each ITA. In the sharp-dissection group, the endothelial surfaces were lined with normal amounts of original endothelium, endothelial cells were distinctly attached to the basal lamina, cytoplasmic organelles were evident, and intercellular junctional complexes were intact. Conversely, in the electrocautery group, the morphologic integrity of endothelial cells was distorted, with some cell separations and splits, contracted cells, numerous large cytoplasmic vacuoles, and no visible cytoplasmic organelles. The subendothelial layer exhibited disintegration. Free ITA flow was higher in the sharp-dissection group (P=0.04). The integrity of endothelial cells can be better preserved when the ITA is mobilized by means of sharp dissection, rather than solely by electrocautery; we recommend a combined approach.

Design and implementation of a simple on-line time-activity curve detector for [O-15] water PET studies

International Nuclear Information System (INIS)

Wollenweber, S.D.; Hichwa, R.D.; Ponto, L.L.B.

1996-01-01

A simple, automated on-line detector system has been fabricated and implemented to detect the arterial time-activity curve (TAC) for water PET studies. This system offers two significant improvements over existing systems: a pump mechanism is not required to control arterial blood flow through the detector and dispersion correction of the time-activity curve is unnecessary. The positrons emanating from a thin-walled, 0.134 cm inner-diameter plastic tube are detected by a 0.5 cm wide by 1.0 cm long by 0.1 cm thick plastic scintillator mounted to a miniature PMT. Photon background is shielded by a 2.0 cm thick cylindrical lead shield. Mean cerebral blood flow (mCBF) calculated from the TAC determined by 1-second automated sampling was compared to that calculated from every 5-second integrated manual samples. Improvements in timing resolution (1-sec vs. 5-sec) cause small but significant differences between the two sampling methods. Dispersion is minimized due to small tubing diameters, short lengths of tubing between the radial arterial sampling site and the detector and the presence of a 3-way valve 10 cm proximal to the detector

[Baroreflexes originated in vertebral artery zones upon peripheral vein tonus, systemic arterial blood pressure, and external respiration].

Science.gov (United States)

Agadzhanian, N A; Kupriianov, S V

2008-06-01

The investigation was intended to study the role ofbaroreceptors ofhemodynamically isolated zone of vertebral arteries in regulation of peripheral veins tonus, arterial pressure and external respiration. Pressure decrease in this vascular reflexogenic zone led to reflex responses of increase in femoral vein tonus, elevation of blood pressure level and stimulation of external respiration. The opposite reflex responses of cardio-respiratory functional system to initial pressure activation of vertebral arteries baroreceptors are observed. Basing on generalization of our own findings and similar physiological and morphological researches of other authors, it is established that afferentation from the vertebral artery zone is a reflexogenic factor of somatic muscles' veins tonus regulation. These reflexes of capacity vessels tonic activity changes are part of cardio-respiratory responses of maintaining the tissue gaseous exchange.

Prostatic Tissue Elimination After Prostatic Artery Embolization (PAE): A Report of Three Cases

Energy Technology Data Exchange (ETDEWEB)

Leite, Leandro Cardarelli; Assis, Andre Moreira de; Moreira, Airton Mota [University of Sao Paulo, Department of Radiology (Brazil); Harward, Sardis Honoria [The Dartmouth Institute for Health Policy and Clinical Practice (United States); Antunes, Alberto Azoubel [University of Sao Paulo, Discipline of Urology (Brazil); Carnevale, Francisco Cesar, E-mail: francisco.carnevale@criep.com.br [University of Sao Paulo, Department of Radiology (Brazil)

2017-06-15

PurposeWe report three cases of spontaneous prostatic tissue elimination through the urethra while voiding following technically successful prostatic artery embolization (PAE) as a treatment for lower urinary tract symptoms (LUTS) related to benign prostatic hyperplasia (BPH).MethodsAll patients were embolized with 100- to 300-μm microspheres alone or in combination with 300- to 500-μm microspheres.ResultsDuring follow-up prior to eliminating the tissue fragments, the three patients all presented with intermittent periods of LUTS improvement and aggravation. After expelling the prostatic tissue between 1 and 5 months of follow-up, significant improvements in LUTS and urodynamic parameters were observed in all patients.ConclusionsUrethral obstruction after PAE caused by sloughing prostate tissue is a potential complication of the procedure and should be considered in patients with recurrent LUTS in order to avoid inappropriate management.

Non-marfan idiopathic medionecrosis (cystic medial necrosis) presenting with multiple visceral artery aneurysms and diffuse connective tissue fragility: Two brothers

International Nuclear Information System (INIS)

Kubota, Jun; Tsunemura, Mami; Amano, Shigeko; Tokizawa, Shigemi; Oowada, Susumu; Shinkai, Hiroko; Maehara, Yasunobu; Endo, Keigo

1997-01-01

Two brothers with multiple visceral artery aneurysms or dilatations and diffuse connective tissue fragility who did not have clinical features of Marfan syndrome are reported. One presented with retroperitoneal hemorrhage during angiography, and idiopathic medionecrosis was proved by resection of the aneurysms. These cases belong to the heterogeneous group of Marfan syndrome. The angiographical features (multiple dilation of visceral arteries) suggests fragility of connective tissue and is predictive of hazards during and after a catheterization and operation

Non-marfan idiopathic medionecrosis (cystic medial necrosis) presenting with multiple visceral artery aneurysms and diffuse connective tissue fragility: Two brothers

Energy Technology Data Exchange (ETDEWEB)

Kubota, Jun [Gunma University School of Medicine, Department of Nuclear Medicine (Japan); Tsunemura, Mami [Gunma University School of Medicine, Department of Diagnostic Radiology (Japan); Amano, Shigeko [Gunma University School of Medicine, Department of Nuclear Medicine (Japan); Tokizawa, Shigemi [Gunma University School of Medicine, Department of Hygiene and Virology (Japan); Oowada, Susumu [Gunma University School of Medicine, Department of Second Surgery (Japan); Shinkai, Hiroko [Gunma Health Foundation (Japan); Maehara, Yasunobu [Gunma University School of Medicine, Department of Diagnostic Radiology (Japan); Endo, Keigo [Gunma University School of Medicine, Department of Nuclear Medicine (Japan)

1997-05-15

Two brothers with multiple visceral artery aneurysms or dilatations and diffuse connective tissue fragility who did not have clinical features of Marfan syndrome are reported. One presented with retroperitoneal hemorrhage during angiography, and idiopathic medionecrosis was proved by resection of the aneurysms. These cases belong to the heterogeneous group of Marfan syndrome. The angiographical features (multiple dilation of visceral arteries) suggests fragility of connective tissue and is predictive of hazards during and after a catheterization and operation.

A Mechanobiological model for damage-induced growth in arterial tissue with application to in-stent restenosis

Science.gov (United States)

Fereidoonnezhad, B.; Naghdabadi, R.; Sohrabpour, S.; Holzapfel, G. A.

In-stent restenosis (ISR) is one of the main drawbacks of stent implementation which limits the long-term success of the procedure. Morphological changes occurring within the arterial wall due to stent-induced mechanical injury are a major cause for activation of vascular smooth muscle cells (VSMCs), and the subsequent development of ISR. Considering the theory of volumetric mass growth and adopting a multiplicative decomposition of the deformation gradient into an elastic part and a growth part, we present a mechanobiological model for ISR. An evolution equation is developed for mass growth of the neointima, in which the activation of VSMCs due to stent-induced damage (injury) and the proliferation rate of the activated cells are considered. By introducing the mass evolution into the mass balance equation, we obtain the evolution of the growth tensor over time. The model is implemented in a finite element code and the procedure of angioplasty is simulated, whereby the features of the proposed growth model are illustrated.

Segmental hepatic artery at hepatic hilar area. Analysis by 3 dimensional integrated image of artery, portal vein and bile duct

Energy Technology Data Exchange (ETDEWEB)

Sakai, Hisamune; Okuda, Kouji; Yoshida, Jun; Kinoshita, Hisafumi; Aoyagi, Shigeaki [Kurume Univ., School of Medicine, Kurume, Fukuoka (Japan)

2006-11-15

Multiple individual variations in running and bifurcation of the hepatic artery, biliary duct and portal vein are known in hepatic hilar area. This paper describes the examination of such arterial variations by integrating the 3D images of those vessels obtained by multidetector-row CT (MDCT). Subjects are findings from 64 patients with cholangiocarcinoma, hepatocarcinoma or cholelithiasis. MDCT dynamic scanning, and percutaneous transhepatic biliary drainage-CT and/or drip infusion cholangiography-CT with the intravenous iopamidol and/or iotroxate megulumin, were done with GE LightSpeed Ultra 16 slice type equipment to compose the 3D images. Arterial variants of the bifurcation in the right and left lobe were found to be 18 cases/62 (29%) and 13/64 (20%), respectively. The left artery running at right side of portal venous umbilical region was seen in 9/64 (14%) and right artery running ''northward'', in 9/62 (14%). Previous realization of such individual 3D arterial variations as above is necessary for the precise microsurgery of the hilar area to preserve the essential vessel. (T.I.)

Segmental hepatic artery at hepatic hilar area. Analysis by 3 dimensional integrated image of artery, portal vein and bile duct

International Nuclear Information System (INIS)

Sakai, Hisamune; Okuda, Kouji; Yoshida, Jun; Kinoshita, Hisafumi; Aoyagi, Shigeaki

2006-01-01

Multiple individual variations in running and bifurcation of the hepatic artery, biliary duct and portal vein are known in hepatic hilar area. This paper describes the examination of such arterial variations by integrating the 3D images of those vessels obtained by multidetector-row CT (MDCT). Subjects are findings from 64 patients with cholangiocarcinoma, hepatocarcinoma or cholelithiasis. MDCT dynamic scanning, and percutaneous transhepatic biliary drainage-CT and/or drip infusion cholangiography-CT with the intravenous iopamidol and/or iotroxate megulumin, were done with GE LightSpeed Ultra 16 slice type equipment to compose the 3D images. Arterial variants of the bifurcation in the right and left lobe were found to be 18 cases/62 (29%) and 13/64 (20%), respectively. The left artery running at right side of portal venous umbilical region was seen in 9/64 (14%) and right artery running ''northward'', in 9/62 (14%). Previous realization of such individual 3D arterial variations as above is necessary for the precise microsurgery of the hilar area to preserve the essential vessel. (T.I.)

Factors influencing delay time and coronary arterial density during coronary angiography with DSCT.

Science.gov (United States)

Tang, Lijun; Zhu, Xiaomei; Xu, Yi; Yu, Tongfu; Xu, Hai; Tang, Jinhua; Dogra, Vikram; Wang, Dehang

2011-02-01

CT angiography (CTA) plays an important role in diagnosing coronary arterial disease. Delay time and density of the coronary arteries related with patient-specific factors are essential for getting an optimal CTA image. To investigate various factors influencing delay time and coronary arterial density during coronary CTA with dual source CT. One hundred and sixteen consecutive subjects who underwent cardiac DSCT with retrospective ECG-gating were included. Factors including gender, age, height, weight, transversal cardiac diameter (TCD), transversal thoracic diameter (TTD), heart rate (HR), body surface area (BSA = [weight × height/3600](1/2)) and cardiothoracic ratio (CTR = TCD/TTD) were recorded, measured and calculated before administration of contrast media during coronary CT angiography. Delay time was determined as duration from the beginning of the injection to the density in the descending aorta at the level of right main pulmonary artery reaching a threshold of 100 HU. Coronary arterial density was measured at the mid portion of the right coronary artery. Regression analysis and stepwise regression analysis were used to investigate the influence of these factors on delay time and coronary arterial density. Delay time decreased with an increasing HR and it was shorter in women than men. Delay time increased with an increasing TCD. Delay time could be predicted by the formula: DT = 16.651-0.110 × HR + 1.902 × gender + 0.394 × TCD (where DT is abbreviation for delay time, gender is 0 for women and 1 for men). Coronary arterial density decreased with an increasing HR and weight. Coronary arterial density could be predicted by the formula: CAD = 923.42-4.099 × HR-3.293 × weight (CAD = coronary arterial density). There was no relationship between the other factors mentioned above and delay time or coronary arterial density. Delay time is influenced by HR, gender and TCD. Coronary arterial density also changes with HR and weight. So HR, gender, TCD and

Conformally integrated stent cell resonators for wireless monitoring of peripheral artery disease

KAUST Repository

Viswanath, Anupam; Green, Scott Ryan; Kosel, Jü rgen; Gianchandani, Yogesh B.

2013-01-01

This paper presents the design and in vitro evaluation of magnetoelastic sensors intended for wireless monitoring of tissue accumulation in peripheral artery stents. The sensors, shaped like stent cells, are fabricated from 28-μm thick foils

Sphingosine-1-Phosphate Signaling Regulates Myogenic Responsiveness in Human Resistance Arteries.

Directory of Open Access Journals (Sweden)

Sonya Hui

Full Text Available We recently identified sphingosine-1-phosphate (S1P signaling and the cystic fibrosis transmembrane conductance regulator (CFTR as prominent regulators of myogenic responsiveness in rodent resistance arteries. However, since rodent models frequently exhibit limitations with respect to human applicability, translation is necessary to validate the relevance of this signaling network for clinical application. We therefore investigated the significance of these regulatory elements in human mesenteric and skeletal muscle resistance arteries. Mesenteric and skeletal muscle resistance arteries were isolated from patient tissue specimens collected during colonic or cardiac bypass surgery. Pressure myography assessments confirmed endothelial integrity, as well as stable phenylephrine and myogenic responses. Both human mesenteric and skeletal muscle resistance arteries (i express critical S1P signaling elements, (ii constrict in response to S1P and (iii lose myogenic responsiveness following S1P receptor antagonism (JTE013. However, while human mesenteric arteries express CFTR, human skeletal muscle resistance arteries do not express detectable levels of CFTR protein. Consequently, modulating CFTR activity enhances myogenic responsiveness only in human mesenteric resistance arteries. We conclude that human mesenteric and skeletal muscle resistance arteries are a reliable and consistent model for translational studies. We demonstrate that the core elements of an S1P-dependent signaling network translate to human mesenteric resistance arteries. Clear species and vascular bed variations are evident, reinforcing the critical need for further translational study.

Connective Tissue Reflex Massage for Type 2 Diabetic Patients with Peripheral Arterial Disease: Randomized Controlled Trial

Science.gov (United States)

Castro-Sánchez, Adelaida María; Moreno-Lorenzo, Carmen; Matarán-Peñarrocha, Guillermo A.; Feriche-Fernández-Castanys, Belen; Granados-Gámez, Genoveva; Quesada-Rubio, José Manuel

2011-01-01

The objective of this study was to evaluate the efficacy of connective tissue massage to improve blood circulation and intermittent claudication symptoms in type 2 diabetic patients. A randomized, placebo-controlled trial was undertaken. Ninety-eight type 2 diabetes patients with stage I or II-a peripheral arterial disease (PAD) (Leriche-Fontaine classification) were randomly assigned to a massage group or to a placebo group treated using disconnected magnetotherapy equipment. Peripheral arterial circulation was determined by measuring differential segmental arterial pressure, heart rate, skin temperature, oxygen saturation and skin blood flow. Measurements were taken before and at 30 min, 6 months and 1 year after the 15-week treatment. After the 15-week program, the groups differed (P < .05) in differential segmental arterial pressure in right lower limb (lower one-third of thigh, upper and lower one-third of leg) and left lower limb (lower one-third of thigh and upper and lower one-third of leg). A significant difference (P < .05) was also observed in skin blood flow in digits 1 and 4 of right foot and digits 2, 4 and 5 of left foot. ANOVA results were significant (P < .05) for right and left foot oxygen saturation but not for heart rate and temperature. At 6 months and 1 year, the groups differed in differential segmental arterial pressure in upper third of left and right legs. Connective tissue massage improves blood circulation in the lower limbs of type 2 diabetic patients at stage I or II-a and may be useful to slow the progression of PAD. PMID:19933770

Connective Tissue Reflex Massage for Type 2 Diabetic Patients with Peripheral Arterial Disease: Randomized Controlled Trial

Directory of Open Access Journals (Sweden)

Adelaida María Castro-Sánchez

2011-01-01

Full Text Available The objective of this study was to evaluate the efficacy of connective tissue massage to improve blood circulation and intermittent claudication symptoms in type 2 diabetic patients. A randomized, placebo-controlled trial was undertaken. Ninety-eight type 2 diabetes patients with stage I or II-a peripheral arterial disease (PAD (Leriche-Fontaine classification were randomly assigned to a massage group or to a placebo group treated using disconnected magnetotherapy equipment. Peripheral arterial circulation was determined by measuring differential segmental arterial pressure, heart rate, skin temperature, oxygen saturation and skin blood flow. Measurements were taken before and at 30 min, 6 months and 1 year after the 15-week treatment. After the 15-week program, the groups differed (P<.05 in differential segmental arterial pressure in right lower limb (lower one-third of thigh, upper and lower one-third of leg and left lower limb (lower one-third of thigh and upper and lower one-third of leg. A significant difference (P<.05 was also observed in skin blood flow in digits 1 and 4 of right foot and digits 2, 4 and 5 of left foot. ANOVA results were significant (P<.05 for right and left foot oxygen saturation but not for heart rate and temperature. At 6 months and 1 year, the groups differed in differential segmental arterial pressure in upper third of left and right legs. Connective tissue massage improves blood circulation in the lower limbs of type 2 diabetic patients at stage I or II-a and may be useful to slow the progression of PAD.

Estimation of arterial arrival time and cerebral blood flow from QUASAR arterial spin labeling using stable spline.

Science.gov (United States)

Castellaro, Marco; Peruzzo, Denis; Mehndiratta, Amit; Pillonetto, Gianluigi; Petersen, Esben Thade; Golay, Xavier; Chappell, Michael A; Bertoldo, Alessandra

2015-12-01

QUASAR arterial spin labeling (ASL) permits the application of deconvolution approaches for the absolute quantification of cerebral perfusion. Currently, oscillation index regularized singular value decomposition (oSVD) combined with edge-detection (ED) is the most commonly used method. Its major drawbacks are nonphysiological oscillations in the impulse response function and underestimation of perfusion. The aim of this work is to introduce a novel method to overcome these limitations. A system identification method, stable spline (SS), was extended to address ASL peculiarities such as the delay in arrival of the arterial blood in the tissue. The proposed framework was compared with oSVD + ED in both simulated and real data. SS was used to investigate the validity of using a voxel-wise tissue T1 value instead of using a single global value (of blood T1 ). SS outperformed oSVD + ED in 79.9% of simulations. When applied to real data, SS exhibited a physiologically realistic range for perfusion and a higher mean value with respect to oSVD + ED (55.5 ± 9.5 SS, 34.9 ± 5.2 oSVD + ED mL/100 g/min). SS can represent an alternative to oSVD + ED for the quantification of QUASAR ASL data. Analysis of the retrieved impulse response function revealed that using a voxel wise tissue T1 might be suboptimal. © 2014 Wiley Periodicals, Inc.

Factors influencing delay time and coronary arterial density during coronary angiography with DSCT

International Nuclear Information System (INIS)

Lijun Tang; Xiaomei Zhu; Yi Xu; Tongfu Yu; Hai Xu; Jinhua Tang; Dehang Wang; Dogra, Vikram

2011-01-01

Background: CT angiography (CTA) plays an important role in diagnosing coronary arterial disease. Delay time and density of the coronary arteries related with patient-specific factors are essential for getting an optimal CTA image. Purpose: To investigate various factors influencing delay time and coronary arterial density during coronary CTA with dual source CT. Material and Methods: One hundred and sixteen consecutive subjects who underwent cardiac DSCT with retrospective ECG-gating were included. Factors including gender, age, height, weight, transversal cardiac diameter (TCD), transversal thoracic diameter (TTD), heart rate (HR), body surface area (BSA = [weight x height/3600]1/2) and cardiothoracic ratio (CTR = TCD/TTD) were recorded, measured and calculated before administration of contrast media during coronary CT angiography. Delay time was determined as duration from the beginning of the injection to the density in the descending aorta at the level of right main pulmonary artery reaching a threshold of 100 HU. Coronary arterial density was measured at the mid portion of the right coronary artery. Regression analysis and stepwise regression analysis were used to investigate the influence of these factors on delay time and coronary arterial density. Results: Delay time decreased with an increasing HR and it was shorter in women than men. Delay time increased with an increasing TCD. Delay time could be predicted by the formula: DT = 16.651-0.110 x HR + 1.902 x gender + 0.394 x TCD (where DT is abbreviation for delay time, gender is 0 for women and 1 for men). Coronary arterial density decreased with an increasing HR and weight. Coronary arterial density could be predicted by the formula: CAD = 923.42-4.099 x HR-3.293 x weight (CAD = coronary arterial density). There was no relationship between the other factors mentioned above and delay time or coronary arterial density. Conclusion: Delay time is influenced by HR, gender and TCD. Coronary arterial density

Central Artery Stiffness, Baroreflex Sensitivity, and Brain White Matter Neuronal Fiber Integrity in Older Adults

Science.gov (United States)

Tarumi, Takashi; de Jong, Daan L.K.; Zhu, David C.; Tseng, Benjamin Y.; Liu, Jie; Hill, Candace; Riley, Jonathan; Womack, Kyle B.; Kerwin, Diana R.; Lu, Hanzhang; Cullum, C. Munro; Zhang, Rong

2015-01-01

Cerebral hypoperfusion elevates the risk of brain white matter (WM) lesions and cognitive impairment. Central artery stiffness impairs baroreflex, which controls systemic arterial perfusion, and may deteriorate neuronal fiber integrity of brain WM. The purpose of this study was to examine the associations among brain WM neuronal fiber integrity, baroreflex sensitivity (BRS), and central artery stiffness in older adults. Fifty-four adults (65±6 years) with normal cognitive function or mild cognitive impairment (MCI) were tested. The neuronal fiber integrity of brain WM was assessed from diffusion metrics acquired by diffusion tensor imaging. BRS was measured in response to acute changes in blood pressure induced by bolus injections of vasoactive drugs. Central artery stiffness was measured by carotid-femoral pulse wave velocity (cfPWV). The WM diffusion metrics including fractional anisotropy (FA) and radial (RD) and axial (AD) diffusivities, BRS, and cfPWV were not different between the control and MCI groups. Thus, the data from both groups were combined for subsequent analyses. Across WM, fiber tracts with decreased FA and increased RD were associated with lower BRS and higher cfPWV, with many of the areas presenting spatial overlap. In particular, the BRS assessed during hypotension was strongly correlated with FA and RD when compared with hypertension. Executive function performance was associated with FA and RD in the areas that correlated with cfPWV and BRS. These findings suggest that baroreflex-mediated control of systemic arterial perfusion, especially during hypotension, may play a crucial role in maintaining neuronal fiber integrity of brain WM in older adults. PMID:25623500

Tissue at risk in the deep middle cerebral artery territory is critical to stroke outcome

Energy Technology Data Exchange (ETDEWEB)

Rosso, Charlotte; Samson, Yves [Pitie-Salpetriere Hospital, AP-HP, Urgences Cerebro-Vasculaires, Paris (France); UPMC, Univ Paris 06, Paris (France); Centre de Recherche de l' Institut du Cerveau et de la Moelle epiniere, ICM, UPMC Paris 6, Inserm, U975, CNRS, UMR 7225, COGIMAGE, Paris (France); Colliot, Olivier [UPMC, Univ Paris 06, Paris (France); Centre de Recherche de l' Institut du Cerveau et de la Moelle epiniere, ICM, UPMC Paris 6, Inserm, U975, CNRS, UMR 7225, COGIMAGE, Paris (France); Valabregue, Romain [UPMC, Univ Paris 06, Paris (France); Centre de Recherche de l' Institut du Cerveau et de la Moelle epiniere, ICM, UPMC Paris 6, Inserm, U975, CNRS, UMR 7225, Centre for NeuroImaging Research (CENIR), Paris (France); Crozier, Sophie [Pitie-Salpetriere Hospital, AP-HP, Urgences Cerebro-Vasculaires, Paris (France); Dormont, Didier [UPMC, Univ Paris 06, Paris (France); Centre de Recherche de l' Institut du Cerveau et de la Moelle epiniere, ICM, UPMC Paris 6, Inserm, U975, CNRS, UMR 7225, COGIMAGE, Paris (France); Pitie-Salpetriere Hospital, AP-HP, Department of Neuroradiology, Paris (France); Lehericy, Stephane [UPMC, Univ Paris 06, Paris (France); Centre de Recherche de l' Institut du Cerveau et de la Moelle epiniere, ICM, UPMC Paris 6, Inserm, U975, CNRS, UMR 7225, Centre for NeuroImaging Research (CENIR), Paris (France); Pitie-Salpetriere Hospital, AP-HP, Department of Neuroradiology, Paris (France)

2011-10-15

The clinical efficacy of thrombolysis in stroke patients is explained by the increased rate of recanalization, which limits infarct growth. However, the efficacy could also be explained by the protection of specific sites of the brain. Here, we investigate where is this outcome-related tissue at risk using voxel-based analysis. We included 68 acute stroke patients with middle cerebral artery (MCA) occlusion on the admission MRI performed within 6 h of symptoms onset (H6) and 16 controls. MCA recanalization was assessed using the magnetic resonance angiography performed at day 1 (D1). Apparent diffusion coefficient (ADC) changes were analyzed using a voxel-based method between patients vs. controls group at admission (H6) in non-recanalized vs. recanalized and in 3-month poor vs. good outcome patients at D1. Complete or partial MCA recanalization was observed in 52 of 68 patients. Good outcome at 3 months occurred in 40 patients (59%). In non-recanalized patients, ADC was decreased in the deep MCA and watershed arterial territory (the lenticular nucleus, internal capsule, and the overlying periventricular white matter). This decrease was not observed in recanalized patients at D1 or patients at H6. Fiber tracking suggested that the area is crossed by the cortico-spinal, cerebellar, and intra-hemispheric association tracts. Finally, this area almost co-localized with the area associated with poor outcome. A clinically relevant area of tissue at risk may occur in patients with MCA infarcts at the level of deep white matter fiber tracts. These findings suggest that neuroprotection research should be refocused on white matter. (orig.)

Tissue at risk in the deep middle cerebral artery territory is critical to stroke outcome

International Nuclear Information System (INIS)

Rosso, Charlotte; Samson, Yves; Colliot, Olivier; Valabregue, Romain; Crozier, Sophie; Dormont, Didier; Lehericy, Stephane

2011-01-01

The clinical efficacy of thrombolysis in stroke patients is explained by the increased rate of recanalization, which limits infarct growth. However, the efficacy could also be explained by the protection of specific sites of the brain. Here, we investigate where is this outcome-related tissue at risk using voxel-based analysis. We included 68 acute stroke patients with middle cerebral artery (MCA) occlusion on the admission MRI performed within 6 h of symptoms onset (H6) and 16 controls. MCA recanalization was assessed using the magnetic resonance angiography performed at day 1 (D1). Apparent diffusion coefficient (ADC) changes were analyzed using a voxel-based method between patients vs. controls group at admission (H6) in non-recanalized vs. recanalized and in 3-month poor vs. good outcome patients at D1. Complete or partial MCA recanalization was observed in 52 of 68 patients. Good outcome at 3 months occurred in 40 patients (59%). In non-recanalized patients, ADC was decreased in the deep MCA and watershed arterial territory (the lenticular nucleus, internal capsule, and the overlying periventricular white matter). This decrease was not observed in recanalized patients at D1 or patients at H6. Fiber tracking suggested that the area is crossed by the cortico-spinal, cerebellar, and intra-hemispheric association tracts. Finally, this area almost co-localized with the area associated with poor outcome. A clinically relevant area of tissue at risk may occur in patients with MCA infarcts at the level of deep white matter fiber tracts. These findings suggest that neuroprotection research should be refocused on white matter. (orig.)

Twenty-four-hour exposure to altered blood flow modifies endothelial Ca2+-activated K+ channels in rat mesenteric arteries

DEFF Research Database (Denmark)

Hilgers, Rob H P; Janssen, Ger M J; Fazzi, Gregorio E

2010-01-01

We tested the hypothesis that changes in arterial blood flow modify the function of endothelial Ca2+-activated K+ channels [calcium-activated K+ channel (K(Ca)), small-conductance calcium-activated K+ channel (SK3), and intermediate calcium-activated K+ channel (IK1)] before arterial structural...... remodeling. In rats, mesenteric arteries were exposed to increased [+90%, high flow (HF)] or reduced blood flow [-90%, low flow (LF)] and analyzed 24 h later. There were no detectable changes in arterial structure or in expression level of endothelial nitric-oxide synthase, SK3, or IK1. Arterial relaxing...... arteries, the balance between the NO/prostanoid versus EDHF response was unaltered. However, the contribution of IK1 to the EDHF response was enhanced, as indicated by a larger effect of TRAM-34 and a larger residual NS309-induced relaxation in the presence of UCL 1684. Reduction of blood flow selectively...

[Vascular aging, arterial hypertension and physical activity].

Science.gov (United States)

Schmidt-Trucksäss, A; Weisser, B

2011-11-01

The present review delineates the significance of intima-media-thickness, arterial stiffness and endothelial function for vascular aging. There is profound evidence for an increase in intima-media-thickness and vascular stiffness not only during healthy aging but induced also by cardiovascular risk factors. There is a central role of arterial hypertension for this progression in both structural factors. In addition, both parameters are strongly associated with cardiovascular risk. Endothelial function measured as postischemic flow-mediated vasodilatation is a functional parameter which is decreased both in healthy aging and by cardiovascular risk factors. Physical activity modifies the influence of aging and risk factors on endothelial function. A positive influence of endurance exercise on vascular stiffness and endothelial function has been demonstrated in numerous studies. In long-term studies, regular physical activity has been shown to reduce the progression of intima-media-thickness. Thus, arterial hypertension accelerates vascular aging, while physical activity has a positive influence on a variety of vascular parameters associated with vascular aging. © Georg Thieme Verlag KG Stuttgart · New York.

Technetium-99m-labeled recombinant tissue plasminogen activator for the imaging of emboli in vivo

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Akihiro; Itoh, Kazuo; Tsukamoto, Eriko; Furudate, Masayori; Kamiyama, Hiroyasu; Abe, Hiroshi [Hokkaido Univ., Sapporo (Japan). School of Medicine

1993-07-01

Tissue-type plasminogen activator (t-PA) effectively lyses activate thrombus by direct action. Recombinant t-PA (rt-PA) was labeled with technetium-99m ([sup 99m]Tc) to investigate the in vivo binding to fibrin clots in a feline cerebral embolism model created by insertion of an artificial fibrin clot within the carotid artery. [sup 99m]Tc-rt-PA administered intravenously provided clearer imaging of clots after priming with cold rt-PA, with uptake peaking 5-10 minutes after the injection. [sup 99m]Tc-labeled human serum albumin was not retained at clot sites. Systemically administered [sup 99m]Tc-rt-PA binds to fibrin clots within carotid arteries in our feline model. Our results suggest that the interaction of intrinsic plasminogen activator inhibitors with extrinsically administered rt-PA may regulate the demonstration of a clot, although the precise mechanism is unclear. (author).

Impact of in Vivo Ischemic Time on RNA Quality

DEFF Research Database (Denmark)

Olsen, Jesper; Kierkeby, Lene T.; Eiholm, Susanne

2015-01-01

immediately following the tumor removal. The time from clamping the main arterial supply to resection and removal of the tumor was used to estimate the in vivo ischemic time. We did not observe a significant difference in RNA quality between normal tissue and tumor tissue. We observed a significant......Considerable effort has been made to improve differentiated diagnostics as well as personalized treatment for colorectal cancer patients. High-quality fresh frozen tissue is often required to investigate relevant molecular signatures in these patients. In RNA expression studies, the “RNA integrity...... number” is widely accepted as a reliable marker of RNA quality. Here, we investigate the feasibility of obtaining high-quality tissue from a colon cancer biobank and the impact of in vivo ischemic time and various technical and clinicopathological factors on RNA quality. Biopsies were obtained...

"The Practical Perforator Flap": the sural artery flap for lower extremity soft tissue reconstruction in wounds of war

NARCIS (Netherlands)

O.J.F. van Waes (Oscar); J.A. Halm (Jens); J. Vermeulen (Jefrey); S. Ashford (Sofie)

2012-01-01

textabstractBackground: Sural artery perforator flaps have been described for use as both local flaps and in free tissue transfer. We present the use of this flap for compound soft tissue defects of the lower limb in civilian casualties of armed conflict in Afghanistan. Methods/results: Detailed

Efficacy and Cost-Effectiveness Analysis of Evidence-Based Nursing Interventions to Maintain Tissue Integrity to Prevent Pressure Ulcers and Incontinence-Associated Dermatitis.

Science.gov (United States)

Avşar, Pınar; Karadağ, Ayişe

2018-02-01

A reduction in tissue tolerance promotes the development of pressure ulcers (PUs) and incontinence-associated dermatitis (IAD). To determine the cost-effectiveness and efficacy of evidence-based (EB) nursing interventions on increasing tissue tolerance by maintaining tissue integrity. The study involved 154 patients in two intensive care units (77 patients, control group; 77 patients, intervention group). Data were collected using the following: patient characteristics form, Braden PU risk assessment scale, tissue integrity monitoring form, PU identification form, IAD and severity scale, and a cost table of the interventions. Patients in the intervention group were cared for by nurses trained in the use of the data collection tools and in EB practices to improve tissue tolerance. Routine nursing care was given to the patients in the control group. The researcher observed all patients in terms of tissue integrity and recorded the care-related costs. Deterioration of tissue integrity was observed in 18.2% patients in the intervention group compared to 54.5% in the control group (p cost to increase tissue tolerance prevention in the intervention and control groups was X¯ = $204.34 ± 41.07 and X¯ = $138.90 ± 1.70, respectively. It is recommended that EB policies and procedures are developed to improve tissue tolerance by maintaining tissue integrity. Although the cost of EB preventive initiatives is relatively high compared to those that are not EB, the former provide a significant reduction in the prevalence of tissue integrity deterioration. © 2017 Sigma Theta Tau International.

Dicer activity in neural crest cells is essential for craniofacial organogenesis and pharyngeal arch artery morphogenesis

Science.gov (United States)

Nie, Xuguang; Wang, Qin; Jiao, Kai

2014-01-01

MicroRNAs (miRNAs) play important roles in regulating gene expression during numerous biological/pathological processes. Dicer encodes an RNase III endonuclease that is essential for generating most, if not all, functional miRNAs. In this work, we applied a conditional gene inactivation approach to examine the function of Dicer during neural crest cell (NCC) development. Mice with NCC-specific inactivation of Dicer died perinatally. Cranial and cardiac NCC migration into target tissues was not affected by Dicer disruption, but their subsequent development was disturbed. NCC derivatives and their associated mesoderm-derived cells displayed massive apoptosis, leading to severe abnormalities during craniofacial morphogenesis and organogenesis. In addition, the 4th pharyngeal arch artery (PAA) remodeling was affected, resulting in interrupted aortic arch artery type B (IAA-B) in mutant animals. Taken together, our results show that Dicer activity in NCCs is essential for craniofacial development and pharyngeal arch artery morphogenesis. PMID:21256960

Sympathetic Innervation Promotes Arterial Fate by Enhancing Endothelial ERK Activity.

Science.gov (United States)

Pardanaud, Luc; Pibouin-Fragner, Laurence; Dubrac, Alexandre; Mathivet, Thomas; English, Isabel; Brunet, Isabelle; Simons, Michael; Eichmann, Anne

2016-08-19

Arterial endothelial cells are morphologically, functionally, and molecularly distinct from those found in veins and lymphatic vessels. How arterial fate is acquired during development and maintained in adult vessels is incompletely understood. We set out to identify factors that promote arterial endothelial cell fate in vivo. We developed a functional assay, allowing us to monitor and manipulate arterial fate in vivo, using arteries isolated from quails that are grafted into the coelom of chick embryos. Endothelial cells migrate out from the grafted artery, and their colonization of host arteries and veins is quantified. Here we show that sympathetic innervation promotes arterial endothelial cell fate in vivo. Removal of sympathetic nerves decreases arterial fate and leads to colonization of veins, whereas exposure to sympathetic nerves or norepinephrine imposes arterial fate. Mechanistically, sympathetic nerves increase endothelial ERK (extracellular signal-regulated kinase) activity via adrenergic α1 and α2 receptors. These findings show that sympathetic innervation promotes arterial endothelial fate and may lead to novel approaches to improve arterialization in human disease. © 2016 American Heart Association, Inc.

Formation of tissue factor activity following incubation of recombinant human tissue factor apoprotein with plasma lipoproteins

International Nuclear Information System (INIS)

Sakai, T.; Kisiel, W.

1990-01-01

Incubation of recombinant human tissue factor apoprotein (Apo-TF) with human plasma decreased the recalcified clotting time of this plasma in a time-and dose-dependent manner suggesting relipidation of the Apo-TF by plasma lipoproteins. Incubation of Apo-TF with purified preparations of human very low density, low density and high density lipoproteins resulted in tissue factor activity in a clotting assay. The order of effectiveness was VLDL greater than LDL much greater than HDL. Tissue factor activity generated by incubation of a fixed amount of Apo-TF with plasma lipoproteins was lipoprotein concentration-dependent and saturable. The association of Apo-TF with lipoprotein particles was supported by gel filtration studies in which 125 I-Apo-TF coeluted with the plasma lipoprotein in the void volume of a Superose 6 column in the presence and absence of calcium ions. In addition, void-volume Apo-TF-lipoprotein fractions exhibited tissue factor activity. These results suggest that the factor VIII-bypassing activity of bovine Apo-TF observed in a canine hemophilic model may be due, in part, to its association with plasma lipoproteins and expression of functional tissue factor activity

Real-Time Electrical Bioimpedance Characterization of Neointimal Tissue for Stent Applications

Directory of Open Access Journals (Sweden)

David Rivas-Marchena

2017-07-01

Full Text Available To follow up the restenosis in arteries stented during an angioplasty is an important current clinical problem. A new approach to monitor the growth of neointimal tissue inside the stent is proposed on the basis of electrical impedance spectroscopy (EIS sensors and the oscillation-based test (OBT circuit technique. A mathematical model was developed to analytically describe the histological composition of the neointima, employing its conductivity and permittivity data. The bioimpedance model was validated against a finite element analysis (FEA using COMSOL Multiphysics software. A satisfactory correlation between the analytical model and FEA simulation was achieved in most cases, detecting some deviations introduced by the thin “double layer” that separates the neointima and the blood. It is hereby shown how to apply conformal transformations to obtain bioimpedance electrical models for stack-layered tissues over coplanar electrodes. Particularly, this can be applied to characterize the neointima in real-time. This technique is either suitable as a main mechanism for restenosis follow-up or it can be combined with proposed intelligent stents for blood pressure measurements to auto-calibrate the sensibility loss caused by the adherence of the tissue on the micro-electro-mechanical sensors (MEMSs.

SU-G-IeP1-12: Size Selective Arterial Cerebral Blood Volume Mapping Using Multiple Inversion Time Arterial Spin Labeling

Energy Technology Data Exchange (ETDEWEB)

Jung, Y; Johnston, M; Whitlow, C [Wake Forest School of Medicine, Winston-salem, NC (United States); Liu, H [UT MD Anderson Cancer Center, Houston, TX (United States)

2016-06-15

Purpose: To demonstrate the feasibility of a novel method for size specific arterial cerebral blood volume (aCBV) mapping using pseudo-continuous arterial spin labeling (PCASL), with multiple TI. Methods: Multiple PCASL images were obtained from a subject with TI of [300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000] ms. Each TI pair was averaged six times. Two scans were performed: one without a flow crusher gradient and the other with a crusher gradient (10cm/s in three directions) to remove signals from large arteries. Scan times were 5min. without a crusher gradient and 5.5 min with a crusher gradient. Non-linear fitting algorithm finds the minimum mean squared solution of per-voxel based aCBV, cerebral blood flow, and arterial transit time, and fits the data into a hemodynamic model that represents superposition of blood volume and flow components within a single voxel. Results: aCBV maps with a crusher gradient represent signals from medium and small sized arteries, while those without a crusher gradient represent signals from all sized arteries, indicating that flow crusher gradients can be effectively employed to achieve size-specific aCBV mapping. Regardless of flow crusher, the CBF and ATT maps are very similar in appearance. Conclusion: Quantitative size selective blood volume mapping controlled by a flow crusher is feasible without additional information because the ASL quantification process doesn’t require an arterial input function measured from a large artery. The size specific blood volume mapping is not interfered by sSignals from large arteries do not interfere with size specific aCBV mapping in the applications of interest in for applications in which only medium or small arteries are of interest.

Real-time haptic cutting of high-resolution soft tissues.

Science.gov (United States)

Wu, Jun; Westermann, Rüdiger; Dick, Christian

2014-01-01

We present our systematic efforts in advancing the computational performance of physically accurate soft tissue cutting simulation, which is at the core of surgery simulators in general. We demonstrate a real-time performance of 15 simulation frames per second for haptic soft tissue cutting of a deformable body at an effective resolution of 170,000 finite elements. This is achieved by the following innovative components: (1) a linked octree discretization of the deformable body, which allows for fast and robust topological modifications of the simulation domain, (2) a composite finite element formulation, which thoroughly reduces the number of simulation degrees of freedom and thus enables to carefully balance simulation performance and accuracy, (3) a highly efficient geometric multigrid solver for solving the linear systems of equations arising from implicit time integration, (4) an efficient collision detection algorithm that effectively exploits the composition structure, and (5) a stable haptic rendering algorithm for computing the feedback forces. Considering that our method increases the finite element resolution for physically accurate real-time soft tissue cutting simulation by an order of magnitude, our technique has a high potential to significantly advance the realism of surgery simulators.

Does intravenous administration of recombinant tissue plasminogen activator for ischemic stroke can cause inferior myocardial infarction?

Directory of Open Access Journals (Sweden)

Mostafa Almasi

2016-06-01

Full Text Available Recombinant tissue plasminogen activator (rTPA is one of the main portions of acute ischemic stroke management, but unfortunately has some complications. Myocardial infarction (MI is a hazardous complication of administration of intravenous rTPA that has been reported recently. A 78-year-old lady was admitted for elective coronary artery bypass graft surgery. On the second day of admission, she developed acute left hemiparesis and intravenous rTPA was administered within 120 minutes. Three hours later, she has had chest pain. Rescue percutaneous coronary intervention was performed on right coronary artery due to diagnosis of inferior MI, and the symptoms were resolved.

Mechanical design in arteries.

Science.gov (United States)

Shadwick, R E

1999-12-01

The most important mechanical property of the artery wall is its non-linear elasticity. Over the last century, this has been well-documented in vessels in many animals, from humans to lobsters. Arteries must be distensible to provide capacitance and pulse-smoothing in the circulation, but they must also be stable to inflation over a range of pressure. These mechanical requirements are met by strain-dependent increases in the elastic modulus of the vascular wall, manifest by a J-shaped stress-strain curve, as typically exhibited by other soft biological tissues. All vertebrates and invertebrates with closed circulatory systems have arteries with this non-linear behaviour, but specific tissue properties vary to give correct function for the physiological pressure range of each species. In all cases, the non-linear elasticity is a product of the parallel arrangement of rubbery and stiff connective tissue elements in the artery wall, and differences in composition and tissue architecture can account for the observed variations in mechanical properties. This phenomenon is most pronounced in large whales, in which very high compliance in the aortic arch and exceptionally low compliance in the descending aorta occur, and is correlated with specific modifications in the arterial structure.

Biobanking of human pancreas cancer tissue: impact of ex-vivo procurement times on RNA quality.

Science.gov (United States)

Rudloff, Udo; Bhanot, Umesh; Gerald, William; Klimstra, David S; Jarnagin, William R; Brennan, Murray F; Allen, Peter J

2010-08-01

Tissue banking has become a major initiative at many oncology centers. The influence of warm ex-vivo ischemia times, storage times, and biobanking protocols on RNA integrity and subsequent microarray data is not well documented. A prospective institutional review board-approved protocol for the banking of abdominal neoplasms was initiated at Memorial Sloan-Kettering Cancer Center in 2001. Sixty-four representative pancreas cancer specimens snap-frozen at various ex-vivo procurement times (1 h) and banked during three time periods (2001-2004, 2004-2006, 2006-2008) were processed. RNA integrity was determined by microcapillary electrophoresis using the RNA integrity number (RIN) algorithm and by results of laser-capture microdissection (LCM). Overall, 42% of human pancreas cancer specimens banked under a dedicated protocol yielded RNA with a RIN of > or =7. Limited warm ex-vivo ischemia times did not negatively impact RNA quality (percentage of tissue with total RNA with RIN of > or =7 for 60 min, 42%), and long-term storage of banked pancreas cancer biospecimens did not negatively influence RNA quality (total RNA with RIN of > or =7 banked 2001-2004, 44%; 2004-2006, 38%; 2006-2008, 50%). RNA retrieved from pancreatic cancer samples with RIN of > or =7 subject to LCM yielded RNA suitable for further downstream applications. Fresh-frozen pancreas tissue banked within a standardized research protocol yields high-quality RNA in approximately 50% of specimens and can be used for enrichment by LCM. Quality of tissues of the biobank were not adversely impacted by limited variations of warm ischemia times or different storage periods. This study shows the challenges and investments required to initiate and maintain high-quality tissue repositories.

Integrative exercise and lifestyle intervention increases leisure-time activity in breast cancer patients

DEFF Research Database (Denmark)

Casla, Soraya; Hojman, Pernille; Cubedo, Ricardo

2014-01-01

BACKGROUND: Physical activity has been demonstrated to increase survival in breast cancer patients, but few breast cancer patients meet the general recommendations for physical activity. The aim of this pilot study was to investigate if a supervised integrated counseling and group-based exercise...... program could increase leisure-time activity in women with breast cancer. METHODS: This pilot project, designed as a single-arm study with pre-post testing, consisted of 24 classes of combined aerobic and strength exercise training as well as classes on dietary and health behavior. A total of 48 women...... with breast cancer who were undergoing or had recently completed anticancer treatment completed the study. Leisure-time physical activity, grip strength, functional capacity, quality of life (QoL), and depression were assessed at baseline, after intervention, and at the 12-week follow-up after intervention...

Lab-on-a-brane: A novel physiologically relevant planar arterial model to study transendothelial transport

Science.gov (United States)

Budhwani, Karim Ismail

The tremendous quality of life impact notwithstanding, cardiovascular diseases and Cancer add up to over US$ 700bn each year in financial costs alone. Aging and population growth are expected to further expand the problem space while drug research and development remain expensive. However, preclinical costs can be substantially mitigated by substituting animal models with in vitro devices that accurately model human cardiovascular transport. Here we present a novel physiologically relevant lab-on-a-brane that simulates in vivo pressure, flow, strain, and shear waveforms associated with normal and pathological conditions in large and small blood vessels for studying molecular transport across the endothelial monolayer. The device builds upon previously demonstrated integrated microfluidic loop design by: (a) introducing nanoscale pores in the substrate membrane to enable transmembrane molecular transport, (b) transforming the substrate membrane into a nanofibrous matrix for 3D smooth muscle cell (SMC) tissue culture, (c) integrating electrospinning fabrication methods, (d) engineering an invertible sandwich cell culture device architecture, and (e) devising a healthy co-culture mechanism for human arterial endothelial cell (HAEC) monolayer and multiple layers of human smooth muscle cells (HSMC) to accurately mimic arterial anatomy. Structural and mechanical characterization was conducted using confocal microscopy, SEM, stress/strain analysis, and infrared spectroscopy. Transport was characterized using FITC-Dextran hydraulic permeability protocol. Structure and transport characterization successfully demonstrate device viability as a physiologically relevant arterial mimic for testing transendothelial transport. Thus, our lab-on-a-brane provides a highly effective and efficient, yet considerably inexpensive, physiologically relevant alternative for pharmacokinetic evaluation; possibly reducing animals used in pre-clinical testing, clinical trials cost from false

Tissue Doppler echocardiography reveals distinct patterns of impaired myocardial velocities in different degrees of coronary artery disease

DEFF Research Database (Denmark)

Hoffmann, Soren; Mogelvang, Rasmus; Olsen, Niels Thue

2010-01-01

Aim To determine how the left ventricular wall motion assessed by echocardiographic Tissue Doppler Imaging (TDI) is affected by increasing severity of coronary artery disease (CAD) among patients with stable angina pectoris and preserved ejection fraction. METHODS AND RESULTS: This study comprise...

Exercise training improves endothelial function in resistance arteries of young prehypertensives.

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Beck, D T; Martin, J S; Casey, D P; Braith, R W

2014-05-01

Prehypertension is associated with reduced conduit artery endothelial function and perturbation of oxidant/antioxidant status. It is unknown whether endothelial dysfunction persists to resistance arteries and whether exercise training affects oxidant/antioxidant balance in young prehypertensives. We examined resistance artery function using venous occlusion plethysmography measurement of forearm (FBF) and calf blood flow (CBF) at rest and during reactive hyperaemia (RH), as well as lipid peroxidation (8-iso-PGF2α) and antioxidant capacity (Trolox-equivalent antioxidant capacity; TEAC) before and after exercise intervention or time control. Forty-three unmedicated prehypertensive and 15 matched normotensive time controls met screening requirements and participated in the study (age: 21.1±0.8 years). Prehypertensive subjects were randomly assigned to resistance exercise training (PHRT; n=15), endurance exercise training (PHET; n=13) or time-control groups (PHTC; n=15). Treatment groups exercised 3 days per week for 8 weeks. Peak and total FBF were lower in prehypertensives than normotensives (12.7±1.2 ml min(-1) per100 ml tissue and 89.1±7.7 ml min(-1) per 100 ml tissue vs 16.3±1.0 ml min(-1) per 100 ml tissue and 123.3±6.4 ml min(-1) per 100 ml tissue, respectively; Pendurance training are effective in improving resistance artery endothelial function and oxidant/antioxidant balance in young prehypertensives.

Whole body and tissue cholesterol turnover in the baboon

International Nuclear Information System (INIS)

Dell, R.B.; Mott, G.E.; Jackson, E.M.; Ramakrishnan, R.; Carey, K.D.; McGill, H.C. Jr.; Goodman, D.S.

1985-01-01

Cholesterol turnover was studied in four baboons by injecting [ 14 C]cholesterol 186 days and [ 3 H]cholesterol 4 days before necropsy, and fitting a two- or three-pool model to the resulting specific activity-time data. At necropsy, cholesterol mass and specific activity were determined for the total body and for many tissues. The principal aim of this study was to estimate the extent of cholesterol synthesis in the side pools of the model, by computing the amount of side pool synthesis needed to equal the measured total body cholesterol. Central pool synthesis varied from 61 to 89% of the total cholesterol production rate. Moreover, the finding that the measured total body cholesterol fell within the range obtained from the kinetic analysis by using reasonable assumptions, provides evidence for the physiological validity of the model. A second aim of this study was to explore cholesterol turnover in various tissues. A pool model predicts that rapidly turning over tissues will have higher specific activities at early times and lower specific activities at later times after injection of tracer relative to slowly turning over tissues, except where significant synthesis occurs. Results in all four baboons were similar. Turnover rates for the different tissues loosely fell into three groups which were turning over at fast, intermediate, and slow rates. Finally, the magnitude of variation of cholesterol specific activity was moderate for several distributed tissues (fat, muscle, arteries, and the alimentary tract), but was small for liver. Cholesterol turnover in serial biopsies of skin, muscle, and fat could, however, be fitted with a single pool to estimate tissue turnover rates

Molecular controls of arterial morphogenesis.

Science.gov (United States)

Simons, Michael; Eichmann, Anne

2015-05-08

Formation of arterial vasculature, here termed arteriogenesis, is a central process in embryonic vascular development as well as in adult tissues. Although the process of capillary formation, angiogenesis, is relatively well understood, much remains to be learned about arteriogenesis. Recent discoveries point to the key role played by vascular endothelial growth factor receptor 2 in control of this process and to newly identified control circuits that dramatically influence its activity. The latter can present particularly attractive targets for a new class of therapeutic agents capable of activation of this signaling cascade in a ligand-independent manner, thereby promoting arteriogenesis in diseased tissues. © 2015 American Heart Association, Inc.

Determination of plasminogen/plasmin system components and indicators of lipoproteins oxidative modification under arterial hypertension

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O. I. Yusova

2018-02-01

Full Text Available The present study was investigated of levels of oxidative modification of lipoproteins and content of plasminogen/plasmin system components – tissue-type plasminogen activator (t-PA and plasminogen activators inhibitor-1 (PAI-I, in patients with stage II arterial hypertension (AHT and resistant form. It was established that t-PA level in blood plasma of the patients is 2 times lower under stage II hypertension than normal and 2.5 times lower under resistant AHT. The inhibitor activity is 1.5 and 2 times higher consequently. It is concluded that patients with AHT have a decreased fibrinolytic potential, which can cause thrombotic states. Our evaluation showed a significant accumulation of products of lipid and protein oxidation, decrease of activity of antioxidant enzymes and changes of the activity of high density-lipoproteins-associated enzymes (decrease of paraoxonase-1 activity, increase of myeloperoxidase activity. Oxidized lipoproteins, t-PA and PAI-1 can be used as prognostic markers of development of complications and for evaluating the efficacy of therapy in patients with arterial hypertension.

Arterial Stiffness and Walk Time in Patients with End-Stage Renal Disease

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Abbi D. Lane

2013-04-01

Full Text Available Background: End-stage renal disease patients experience increased prevalence of cardiovascular disease. Heart-artery interaction may be shifted, impacting blood pressure lability, and exercise tolerance. The coupling ratio consists of the ratio of indexed arterial elastance (EaI, arterial load to ElvI, a measure of cardiac contractility or stiffness. Our purpose was to explore the relationship between elastances and functional capacity. We hypothesized that arterial stiffness (central pulse wave velocity, PWV and elastances would be correlated to shuttle walk time. Methods: We used applanation tonometry, ultrasonography, and a shuttle walk test to evaluate our hypothesis. Spearman's correlations were used to assess relationships between variables. Block regression was also performed. Results: Forty-two subjects on maintenance hemodialysis participated. Average age=44±5 years, body surface area=2.01 kg/m2. Mean EaI=4.45 and mean ElvI=6.89; the coupling ratio=0.82. Mean aortic pulse pressure=51 mmHg and PWV=9.6 m/s. PWV(r=-0.385 and EaI (r=-0.424 were significantly and inversely related to walking time while stroke volume index (SVI was positively correlated to shuttle walk time (r=0.337, pConclusions: We conclude that, like other clinical populations, both arterial and heart function predict walking ability and represent potential targets for intervention; arterial stiffness and SVI are strongly related to shuttle walk time in patients with ESRD.

Atomically resolved tissue integration.

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Karlsson, Johan; Sundell, Gustav; Thuvander, Mattias; Andersson, Martin

2014-08-13

In the field of biomedical technology, a critical aspect is the ability to control and understand the integration of an implantable device in living tissue. Despite the technical advances in the development of biomaterials, the elaborate interplay encompassing materials science and biology on the atomic level is not very well understood. Within implantology, anchoring a biomaterial device into bone tissue is termed osseointegration. In the most accepted theory, osseointegration is defined as an interfacial bonding between implant and bone; however, there is lack of experimental evidence to confirm this. Here we show that atom probe tomography can be used to study the implant-tissue interaction, allowing for three-dimensional atomic mapping of the interface region. Interestingly, our analyses demonstrated that direct contact between Ca atoms and the implanted titanium oxide surface is formed without the presence of a protein interlayer, which means that a pure inorganic interface is created, hence giving experimental support to the current theory of osseointegration. We foresee that this result will be of importance in the development of future biomaterials as well as in the design of in vitro evaluation techniques.

Comparison of New Technology Integrated and Nonintegrated Arterial Filters Used in Cardiopulmonary Bypass Surgery: A Randomized, Prospective, and Single Blind Study

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Özgür Gürsu

2013-01-01

Full Text Available Background. Innovative cardiopulmonary bypass (CPB settings have been developed in order to integrate the concepts of “surface-coating,” “blood-filtration,” and “miniaturization.” Objectives. To compare integrated and nonintegrated arterial line filters in terms of peri- and postoperative clinical variables, inflammatory response, and transfusion needs. Material and Methods. Thirty-six patients who underwent coronary bypass surgery were randomized into integrated (Group In and nonintegrated arterial line filter (Group NIn groups. Arterial blood samples for the assessments of complete hemogram, biochemical screening, interleukin-6, interleukin-2R, and C-reactive protein were analyzed before and after surgery. Need for postoperative dialysis, inotropic therapy and transfusion, in addition to extubation time, total amount of drainage (mL, length of intensive care unit, and hospital stay, and mortality rates was also recorded for each patient. Results. Prime volume was significantly higher and mean intraoperative hematocrit value was lower in Group NIn, but need for erythrocyte transfusion was significantly higher in Group NIn. C-reactive protein values did not differ significantly except for postoperative second day's results, which were found significantly lower in Group In than in Group NIn. Conclusion. Intraoperative hematocrit levels were higher and need for postoperative erythrocyte transfusion was decreased in Group In.

Smoking is associated with lower amounts of arterial type I collagen and decorin

DEFF Research Database (Denmark)

Faarvang, Anne-Sofie; Rørdam Preil, Simone; Switten Nielsen, Patricia

2016-01-01

correlation between extracellular matrix content in arterial tissue and cigarette smoking. METHODS: We studied the non-atherosclerotic arterial wall of the internal mammary artery from coronary artery by-pass surgery in 13 never-smokers and 11 active smokers. Using histomorphometric methods, the area fraction...... of collagen stainable material was determined. In addition, proteome analysis of matrix molecules and other proteins was performed. RESULTS: The area fraction of collagen stainable material in smokers vs. never-smokers was 29.1% ± 3.8% vs. 43.3% ± 3.6% (mean ± SEM, p = 0.012) in tunica intima, 39.7% ± 5.5% vs.......118, mean ± SEM, p = 0.038) and decorin (0.64 ± 0.04 vs. 0.98 ± 0.11, mean ± SEM, p = 0.009) in smokers. CONCLUSIONS: Arterial tissue from active smokers contains decreased amounts of collagen stainable material, as well as type 1 collagen and decorin. These findings may explain some effects of smoking...

Increased endothelial apoptotic cell density in human diabetic erectile tissue--comparison with clinical data.

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Costa, Carla; Soares, Raquel; Castela, Angela; Adães, Sara; Hastert, Véronique; Vendeira, Pedro; Virag, Ronald

2009-03-01

Erectile dysfunction (ED) is a common complication of diabetes. Endothelial cell (EC) dysfunction is one of the main mechanisms of diabetic ED. However, loss of EC integrity has never been assessed in human diabetic corpus cavernosum. To identify and quantify apoptotic cells in human diabetic and normal erectile tissue and to compare these results with each patient's clinical data and erection status. Eighteen cavernosal samples were collected, 13 from diabetics with ED and 5 from nondiabetic individuals. Cavernosal structure and cell proliferation status were evaluated by immunohistochemistry. Tissue integrity was assessed by terminal transferase dUTP nick end labeling assay, an index of apoptotic cell density (ACD) established and compared with each patient age, type of diabetes, arterial risk factors number, arterial/veno-occlusive disease, response to intracavernous vasoactive injections (ICI), and penile nitric oxide release test (PNORT). Establish an index of ACD and correlate those results with patient clinical data. Nondiabetic samples presented few scattered cells in apoptosis and an ACD of 7.15 +/- 0.44 (mean apoptotic cells/tissue area mm(2) +/- standard error). The diabetic group showed an increased ACD of 23.82 +/- 1.53, and apoptotic cells were located specifically at vascular sites. Rehabilitation of these endothelial lesions seemed impaired, as no evidence of EC proliferation was observed. Furthermore, higher ACD in diabetic individuals correlated to poor response to PNORT and to ICI. We provided evidence for the first time that loss of cavernosal EC integrity is a crucial event involved in diabetic ED. Furthermore, we were able to establish a threshold between ACD values and cavernosal tissue functionality, as assessed by PNORT and vasoactive ICI.

Reduced endothelial activation after exercise is associated with improved HbA1c in patients with type 2 diabetes and coronary artery disease.

Science.gov (United States)

Byrkjeland, Rune; Njerve, Ida U; Arnesen, Harald; Seljeflot, Ingebjørg; Solheim, Svein

2017-03-01

We have previously reported insignificant changes in HbA 1c after exercise in patients with both type 2 diabetes and coronary artery disease. In this study, we investigated the effect of exercise on endothelial function and possible associations between changes in endothelial function and HbA 1c . Patients with type 2 diabetes and coronary artery disease ( n = 137) were randomised to 12 months exercise or standard follow-up. Endothelial function was assessed by circulating biomarkers (E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, von Willebrand factor, tissue plasminogen activator antigen, asymmetric dimethylarginine and L-arginine/asymmetric dimethylarginine ratio). Differences between the randomised groups were analysed by analysis of covariance and correlations by Spearman's rho or Pearson's correlation. No effect of exercise on endothelial function was demonstrated. The changes in HbA 1c in the exercise group correlated with changes in E-selectin ( r = 0.56, p < 0.001), intercellular adhesion molecule-1 ( r = 0.27, p = 0.052), vascular cell adhesion molecule-1 ( r = 0.32, p = 0.022) and tissue plasminogen activator antigen ( r = 0.35, p =  0.011). HbA 1c decreased significantly more in patients with versus without a concomitant reduction in E-selectin ( p =  0.002), intercellular adhesion molecule-1 ( p =  0.011), vascular cell adhesion molecule-1 ( p =  0.028) and tissue plasminogen activator antigen ( p =  0.009). Exercise did not affect biomarkers of endothelial function in patients with both type 2 diabetes and coronary artery disease. However, changes in biomarkers of endothelial activation correlated with changes in HbA 1c , and reduced endothelial activation was associated with improved HbA 1c after exercise.

3,7-Bis(2-hydroxyethyl)icaritin, a potent inhibitor of phosphodiesterase-5, prevents monocrotaline-induced pulmonary arterial hypertension via NO/cGMP activation in rats.

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Lan, Tao-Hua; Chen, Xiao-Ling; Wu, Yun-Shan; Qiu, Hui-Liang; Li, Jun-Zhe; Ruan, Xin-Min; Xu, Dan-Ping; Lin, Dong-Qun

2018-06-15

Pulmonary arterial hypertension (PAH) is a chronic progressive disease which leads to elevated pulmonary arterial pressure and right heart failure. 3,7-Bis(2-hydroxyethyl)icaritin (ICT), an icariin derivatives, was reported to have potent inhibitory activity on phosphodiesterase type 5 (PDE5) which plays a crucial role in the pathogenesis of PAH. The present study was designed to investigate the effects of ICT on monocrotaline (MCT)-induced PAH rat model and reveal the underlying mechanism. MCT-induced PAH rat models were established with intragastric administration of ICT (10, 20, 40 mg/kg/d), Icariin (ICA) (40 mg/kg/d) and Sildenafil (25 mg/kg/d). The mean pulmonary arterial pressure (mPAP) and right ventricle hypertrophy index (RVHI) were measured. Pulmonary artery remodeling was assessed by H&E staining. Blood and lung tissue were collected to evaluate the level of endothelin 1 (ET-1), nitric oxide (NO), and cyclic guanosine monophosphate (cGMP). The expressions endothelial nitric oxide synthase (eNOS) and PDE5A in lung tissues were determined by Western blot analysis. The results showed that ICT reduced RVHI and mPAP, and reversed lung vascular remodeling in rats with MCT-induced PAH. ICT also reversed MCT-induced ET-1 elevation, NO and cGMP reduction in serum or lung tissue. Moreover, ICT administration significantly induced eNOS activation and PDE5A inhibition. ICT with lower dose had better effects than ICA. In summary, ICT is more effective in preventing MCT-induced PAH in rats via NO/cGMP activation compared with ICA. These findings demonstrate a novel mechanism of the action of ICT that may have value in prevention of PAH. Copyright © 2018 Elsevier B.V. All rights reserved.

Real-time simulation of contact and cutting of heterogeneous soft-tissues.

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Courtecuisse, Hadrien; Allard, Jérémie; Kerfriden, Pierre; Bordas, Stéphane P A; Cotin, Stéphane; Duriez, Christian

2014-02-01

This paper presents a numerical method for interactive (real-time) simulations, which considerably improves the accuracy of the response of heterogeneous soft-tissue models undergoing contact, cutting and other topological changes. We provide an integrated methodology able to deal both with the ill-conditioning issues associated with material heterogeneities, contact boundary conditions which are one of the main sources of inaccuracies, and cutting which is one of the most challenging issues in interactive simulations. Our approach is based on an implicit time integration of a non-linear finite element model. To enable real-time computations, we propose a new preconditioning technique, based on an asynchronous update at low frequency. The preconditioner is not only used to improve the computation of the deformation of the tissues, but also to simulate the contact response of homogeneous and heterogeneous bodies with the same accuracy. We also address the problem of cutting the heterogeneous structures and propose a method to update the preconditioner according to the topological modifications. Finally, we apply our approach to three challenging demonstrators: (i) a simulation of cataract surgery (ii) a simulation of laparoscopic hepatectomy (iii) a brain tumor surgery. Copyright © 2013 Elsevier B.V. All rights reserved.

Contribution to the pathogenesis of radiation-induced injury to large arteries

International Nuclear Information System (INIS)

Zidar, Nina; Ferluga, Dusan; Hvala, Asta; Popovic, Mara; Soba, Erika

1997-01-01

We report a case of a 35-year-old man who died of a brain infarct 20 months after radiotherapy for carcinoma of the tonsil with metastases to the cervical lymph nodes. Histology revealed mild atherosclerosis, necrotizing vasculitis, and occlusive thrombosis of the internal carotid artery. Significant changes were observed in the vasa vasorum; swelling and detachment of the endothelium, subendothelial oedema, hyaline change, fibrinoid necrosis of the vessel walls with mononuclear cellular infiltration, accompanied by focal haemorrhages and chronic inflammation in the periadventitial soft tissue. We believe that these changes of the vasa vasorum and necrotizing vasculitis are causally related and that vasculitis represents focal ischaemic necroses with inflammatory reaction. Our findings support the hypothesis, based on experimental studies, that injury to the vasa vasorum is an important mechanism in the development of radiation-induced vasculopathy of large arteries. They also suggest an evolution of the injury to the vasa vasorum and periadventitial tissue from the early lesions described in our patient, to late stages resulting in dense periadventitial fibrosis as reported previously. We suggest that injury to the vasa vasorum and the consequent ischaemic lesions of the arterial wall are morphological features distinguishing radiation-induced arterial injury from spontaneous atherosclerosis. (author)

Pericyte protection by edaravone after tissue plasminogen activator treatment in rat cerebral ischemia

Science.gov (United States)

Deguchi, Kentaro; Liu, Ning; Liu, Wentao; Omote, Yoshio; Kono, Syoichiro; Yunoki, Taijun; Deguchi, Shoko; Yamashita, Toru; Ikeda, Yoshio; Abe, Koji

2014-01-01

Pericytes play a pivotal role in contraction, mediating inflammation and regulation of blood flow in the brain. In this study, changes of pericytes in the neurovascular unit (NVU) were examined in relation to the effects of exogenous tissue plasminogen activator (tPA) and a free radical scavenger, edaravone. Immunohistochemistry and Western blot analyses showed that the overlap between platelet-derived growth factor receptor β-positive pericytes and N-acetylglucosamine oligomers (NAGO)-positive endothelial cells increased significantly at 4 days after 90 min of transient middle cerebral artery occlusion (tMCAO). The number of pericytes and the overlap with NAGO decreased with tPA but recovered with edaravone 4 days after tMCAO with proliferation. Thus, tPA treatment damaged pericytes, resulting in the detachment from astrocytes and a decrease in glial cell line-derived neurotrophic factor secretion. However, treatment with edaravone greatly improved tPA-induced damage to pericytes. The present study demonstrates that exogenous tPA strongly damages pericytes and destroys the integrity of the NVU, but edaravone treatment can greatly ameliorate such damage after acute cerebral ischemia in rats. © 2014 The Authors. Journal of Neuroscience Research Published by Wiley Periodicals, Inc. PMID:24938625

Integral dose and evaluation of irradiated tissue volume

International Nuclear Information System (INIS)

Sivachenko, T.P.; Kalina, V.K.; Belous, A.K.; Gaevskij, V.I.

1984-01-01

Two parameters having potentialities of radiotherapy planning improvement are under consideration. One of these two parameters in an integral dose. An efficiency of application of special tables for integral dose estimation is noted. These tables were developed by the Kiev Physician Improvement Institute and the Cybernetics Institute of the Ukrainian SSR Academy of Science. The meaning of the term of ''irradiated tissue volume'' is specified, and the method of calculation of the irradiated tissue effective mass is considered. It is possible to evaluate with higher accuracy tolerance doses taking into account the irradiated mass

Relation of time to complete redistribution and the severity of coronary artery disease

International Nuclear Information System (INIS)

Nishimura, Tsunehiko; Uehara, Toshiisa; Hayashida, Kohei; Kozuka, Takahiro; Saito, Muneyasu; Sumiyoshi, Tetsuya

1985-01-01

The relation between the severity of coronary artery disease and the time to complete redistribution (RD) was investigated in 66 patients with angina pectoris (AP) (28 SVD, 18 DVD and 20 TVD) and 104 patients with myocardial infarction (MI) (45 SVD, 36 DVD and 23 TVD). Stress thallium scan was performed immediately, 30 minutes (early) and 4 hours (delayed) after exercise. RD was classified into three groups (complete, incomplete and no RD). Early complete RD was observed in 15 (23 %) of AP and 3 (3 %) of MI cases. In both cases, the incidence of early RD was higher in SVD compared to DVD and TVD. And diffuse slow washout calculated from exercise and RD study disturbed the incidence of early RD in DVD and TVD. In the early RD cases of AP, coronary stenosis showed mild and collateral was not correlated, however, in the complete or incomplete RD of MI, coronary stenosis showed severe (> 90 %) and the frequency of collateral was higher compared to no RD cases. In MI cases, complete, incomplete and no RD were observed in 22 %, 25 % and 53 %, respectively. In the latter, a- or dys-kinesis at infarct zone was often observed which showed myocardial viability. In conclusion, early RD was observed about 20 % of coronary artery disease and the time to complete RD was closely related to the severity of coronary artery disease. In addition, the sensitivity for detecting transient thallium defect was influenced by the delay in beginning imaging. (author)

Brachial artery vasomotion and transducer pressure effect on measurements by active contour segmentation on ultrasound

Energy Technology Data Exchange (ETDEWEB)

Cary, Theodore W.; Sultan, Laith R.; Sehgal, Chandra M., E-mail: sehgalc@uphs.upenn.edu [Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Reamer, Courtney B.; Mohler, Emile R. [Department of Medicine, Division of Cardiovascular Medicine, Section of Vascular Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

2014-02-15

Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging.

Carbogen inhalation increases oxygen transport to hypoperfused brain tissue in patients with occlusive carotid artery disease: increased oxygen transport to hypoperfused brain

DEFF Research Database (Denmark)

Ashkanian, Mahmoud; Gjedde, Albert; Mouridsen, Kim

2009-01-01

to inhaled oxygen (the mixture known as carbogen). In the present study, we measured CBF by positron emission tomography (PET) during inhalation of test gases (O(2), carbogen, and atmospheric air) in healthy volunteers (n = 10) and in patients with occlusive carotid artery disease (n = 6). Statistical...... and Sa(O2) are readily obtained with carbogen, while oxygen increases only Sa(O2). Thus, carbogen improves oxygen transport to brain tissue more efficiently than oxygen alone. Further studies with more subjects are, however, needed to investigate the applicability of carbogen for long-term inhalation...

Calcium as a signal integrator in developing epithelial tissues.

Science.gov (United States)

Brodskiy, Pavel A; Zartman, Jeremiah J

2018-05-16

Decoding how tissue properties emerge across multiple spatial and temporal scales from the integration of local signals is a grand challenge in quantitative biology. For example, the collective behavior of epithelial cells is critical for shaping developing embryos. Understanding how epithelial cells interpret a diverse range of local signals to coordinate tissue-level processes requires a systems-level understanding of development. Integration of multiple signaling pathways that specify cell signaling information requires second messengers such as calcium ions. Increasingly, specific roles have been uncovered for calcium signaling throughout development. Calcium signaling regulates many processes including division, migration, death, and differentiation. However, the pleiotropic and ubiquitous nature of calcium signaling implies that many additional functions remain to be discovered. Here we review a selection of recent studies to highlight important insights into how multiple signals are transduced by calcium transients in developing epithelial tissues. Quantitative imaging and computational modeling have provided important insights into how calcium signaling integration occurs. Reverse-engineering the conserved features of signal integration mediated by calcium signaling will enable novel approaches in regenerative medicine and synthetic control of morphogenesis.

Angiographic picture of soft tissue desmoid fibromas

International Nuclear Information System (INIS)

Nikitaev, N.S.; Kuznetsova, M.A.

1987-01-01

Arteriography was performed in 35 patients with soft tissue desmoid fibromas. Angiographic semiotics of this disease was described. The frequency of detectability of symptoms in the arterial, parenchymatous and venous phases was analyzed. A tumor in the arterial phase was shown to be of normevascular or moderately hypervascular type without noticeable winding of the nutrient arteries, such features of malignancy as lacunae and ''tumor'' vessels being absent. In the parenchymatous phase desmoid tumors were shown to accumulate moderately a contrast substance, a tumor contour at a vast length was ill defined and poorly marked from surrounding tissues. The venous phase was less noticeable and the time of its appearance was usually within normal. In general by most of its parameters the angiographic picture of agressive fibromatosis corresponded to that of benign tumors and could be used for differential diagnosis of desmoid fibromas and some types of tissue sarcomas

Inflammatory processes during arteriogenesis : the contribution of the innate immune system to collateral artery growth

NARCIS (Netherlands)

de Groot, D.

2011-01-01

The central theme of the work presented in the thesis is restoration of tissue perfusion by collateral artery growth. During collateral artery growth, or arteriogenesis, unused pre-existing vascular anastomoses remodel into functional arteries. These arteries are able to take over the perfusion of

Activation of factor VII bound to tissue factor: A key early step in the tissue factor pathway of blood coagulation

International Nuclear Information System (INIS)

Rao, L.V.M.; Rapaport, S.I.

1988-01-01

Whether the factor VII/tissue factor complex that forms in tissue factor-dependent blood coagulation must be activated to factor VIIa/tissue factor before it can activate its substrates, factor X and IX, has been a difficult question to answer because the substrates, once activated, back-activate factor VII. The earlier studies suggested that human factor VII/tissue factor cannot activate factor IX. Studies have now been extended to the activation of factor X. Reaction mixtures were made with purified factor VII, X, and tissue factor; in some experiments antithrombin III and heparin were added to prevent back-activation of factor VII. Factor X was activated at similar rates in reaction mixtures containing either VII or factor VIIa after an initial 30-sec lag with factor VII. In reaction mixtures with factor VII a linear activation of factor X was established several minutes before cleavage of 125 I-labeled factor VII to the two-chain activated molecule was demonstrable on gel profiles. These data suggest that factor VII/tissue factor cannot activate measurable amounts of factor X over several minutes. Overall, the results support the hypothesis that a rapid preferential activation of factor VII bound to tissue factor by trace amounts of factor Xa is a key early step in tissue factor-dependent blood coagulation

Inverse relationship between physical activity and arterial stiffness in adults with hypertension.

Science.gov (United States)

O'Donovan, Cuisle; Lithander, Fiona E; Raftery, Tara; Gormley, John; Mahmud, Azra; Hussey, Juliette

2014-02-01

Physical activity has beneficial effects on arterial stiffness among healthy adults. There is a lack of data on this relationship in adults with hypertension. The majority of studies which have examined physical activity and arterial stiffness have used subjective measures of activity. The aim of this study was to investigate the relationship between objectively measured habitual physical activity and arterial stiffness in individuals with newly diagnosed essential hypertension. Adults attending an outpatient hypertension clinic were recruited into this cross sectional study. Physical activity was measured using a triaxial accelerometer. Pulse wave velocity (PWV) and augmentation index (AIx) were measured using applanation tonometry. Participant's full lipid profile and glucose were determined through the collection of a fasting blood sample. Fifty-three adults [51(14) years, 26 male] participated, 16 of whom had the metabolic syndrome. Inactivity was positively correlated with PWV (r = .53, P arterial stiffness among adults with hypertension.

Activation of factor VII bound to tissue factor: a key early step in the tissue factor pathway of blood coagulation.

OpenAIRE

Rao, L V; Rapaport, S I

1988-01-01

Whether the factor VII/tissue factor complex that forms in tissue factor-dependent blood coagulation must be activated to factor VIIa/tissue factor before it can activate its substrates, factor X and factor IX, has been a difficult question to answer because the substrates, once activated, back-activate factor VII. Our earlier studies suggested that human factor VII/tissue factor cannot activate factor IX. Studies have now been extended to the activation of factor X. Reaction mixtures were ma...

Combination of dynamic and integral methods for generating reproducible functional CBF images

International Nuclear Information System (INIS)

Lammertsma, A.A.; Cunningham, V.J.; Deiber, M.P.; Heather, J.D.; Bloomfield, P.M.; Nutt, J.; Frackowiak, R.S.; Jones, T.

1990-01-01

A new method to measure regional CBF is presented, applying both dynamic and integral analyses to a dynamic sequence of positron emission tomographic scans collected during and following the administration of H2(15)O (inhalation of C15O2). The dynamic analysis is used to correct continuously monitored arterial whole-blood activity for delay and dispersion relative to tissue scans. An integral analysis including corrections for this delay and dispersion is then used to calculate CBF on a pixel-by-pixel basis. Normal values and reproducibility over a 2-h period are presented, together with the results of validation and simulation studies. The results indicate that the single-tissue compartment model adequately describes the distribution of H2(15)O in the brain, without recourse to postulating a nonexchanging water pool

Biobanking of Fresh-Frozen Cancer Tissue: RNA Is Stable Independent of Tissue Type with Less Than 1 Hour of Cold Ischemia.

Science.gov (United States)

Song, Sang Yong; Jun, Jonghyun; Park, Miyeon; Park, Seo Kyu; Choi, Wonju; Park, Kyunghee; Jang, Kee-Taek; Lee, Myoyong

2018-02-01

The effects of preanalytical variables in tissue processing and storage periods on RNA quality of tissues have been well documented in each type of cancer. However, few studies have been performed on a comparative assessment of the impacts across different cancer tissues, even though it is well known that RNase activity is highly variable in various tissue types and RNase-rich tissues have been found to yield low-quality RNA. We investigated the impacts of cold ischemia times and long-term storage on RNA integrity in various types of cancer tissue, which had been fresh-frozen and collected at the Samsung Medical Center Biobank. RNA quality was also evaluated with regard to histopathological variables. We analyzed RNA integrity number (RIN) data, which had been obtained from our quality control (QC) processes over the last 7 years. Approximately 2% of samples were randomly selected and processed to measure RIN quarterly and after 6 years of storage for QC purposes. Fresh-frozen tumor tissues yielded high-quality RNA regardless of tumor type and histopathological features. Up to 1-hour cold ischemia times and up to 6-year storage times did not adversely influence RNA integrity. Only 3 samples showed RIN of <7 out of a total of 396 analyzed tumor tissues. Tissue quality was not adversely affected by long-term storage or limited variations of cold ischemia times. The low-quality samples could be correlated with the structural composition or intratumoral heterogeneity of tissues. The strict application of standardized protocols for tissue collection is the key for high-quality biobanking.

Sphenopalatine Artery Ligation for Epistaxis: Factors Influencing Outcome and Impact of Timing of Surgery.

Science.gov (United States)

McDermott, Ailbhe M; O'Cathain, Eadaoin; Carey, Brian William; O'Sullivan, Peter; Sheahan, Patrick

2016-03-01

Sphenopalatine artery ligation is a commonly employed surgical intervention for control of posterior epistaxis unresponsive to nasal packing. The objective of the present study was to evaluate the outcome of sphenopalatine artery ligation for control of epistaxis at our institution and the impact of timing and other factors on outcome. Case series with chart review. Academic tertiary referral center. Case notes were reviewed for 45 consecutive patients undergoing sphenopalatine artery ligation for control of epistaxis between October 2008 and October 2014. Forty-one patients had nasal packing prior to sphenopalatine artery ligation, with 33 undergoing ≥2 packings. Postoperatively, 6 patients had rebleeding, which was treated with repacking (n = 4) and return to the operating room (n = 2). The overall success rate of sphenopalatine artery ligation was 87% (39 of 45). Rebleeding rate was not affected by concomitant septoplasty, anterior ethmoidal artery ligation, or postoperative nasal packing. Patients undergoing SPA ligation within the first 24 hours of admission had a significantly shorter hospital length of stay (3 vs 6 days, P = .02) and treatment cost (€5905 vs €10,001, P = .03). Length of stay was not influenced by sphenopalatine artery ligation after ≤1 nasal pack versus ≥2 packs. Timing of sphenopalatine artery ligation did not affect blood transfusion requirement (P = .84). Sphenopalatine artery ligation is an effective management strategy for surgical control of refractory epistaxis. Early timing of sphenopalatine artery ligation may lead to reductions in length of stay. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

Catalase activity prevents exercise-induced up-regulation of vasoprotective proteins in venous tissue.

Science.gov (United States)

Dao, Vu Thao-Vi; Floeren, Melanie; Kumpf, Stephanie; Both, Charlotte; Peter, Bärbel; Balz, Vera; Suvorava, Tatsiana; Kojda, Georg

2011-11-01

Physical activity induces favourable changes of arterial gene expression and protein activity, although little is known about its effect in venous tissue. Although our understanding of the initiating molecular signals is still incomplete, increased expression of endothelial nitric oxide synthase (eNOS) is considered a key event. This study sought to investigate the effects of two different training protocols on the expression of eNOS and extracellular superoxide dismutase (ecSOD) in venous and lung tissue and to evaluate the underlying molecular mechanisms. C57Bl/6 mice underwent voluntary exercise or forced physical activity. Changes of vascular mRNA and protein levels and activity of eNOS, ecSOD and catalase were determined in aorta, heart, lung and vena cava. Both training protocols similarly increased relative heart weight and resulted in up-regulation of aortic and myocardial eNOS. In striking contrast, eNOS expression in vena cava and lung remained unchanged. Likewise, exercise up-regulated ecSOD in the aorta and in left ventricular tissue but remained unchanged in lung tissue. Catalase expression in lung tissue and vena cava of exercised mice exceeded that in aorta by 6.9- and 10-fold, respectively, suggesting a lack of stimulatory effects of hydrogen peroxide. In accordance, treatment of mice with the catalase inhibitor aminotriazole for 6 weeks resulted in significant up-regulation of eNOS and ecSOD in vena cava. These data suggest that physiological venous catalase activity prevents exercise-induced up-regulation of eNOS and ecSOD. Furthermore, therapeutic inhibition of vascular catalase might improve pulmonary rehabilitation. © 2011 The Authors Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

Catheter placement via the occipital artery to achieve superselective intra-arterial chemotherapy for oral cancer

International Nuclear Information System (INIS)

Iwai, Toshinori; Mitsudo, Kenji; Fukui, Takafumi

2008-01-01

Superselective intra-arterial chemotherapy via the superficial temporal artery (STA) has become useful for oral cancer. However, this method can not be performed if catheter placement via the STA is impossible. Therefore, we report a surgical method for catheter placement via the occipital artery (OA) to achieve retrograde superselective intra-arterial chemotherapy. Preoperatively, three-dimensional computed tomography angiography was performed to identify the course of the external carotid artery and the relationship between OA and the target artery. Ten patients with oral cancer underwent catheter placement via the OA with Doppler ultrasound and Harmonic Scalpel under local anesthesia. Catheter placement via the OA was superselectively successful in all the patients. The mean exposure time of OA and mean operating time were 17.5 min and 70.5 min, respectively. Catheter placement via the OA is useful when catheter placement via the STA is impossible. Three-dimensional vascular mapping and the use of Doppler ultrasound and Harmonic Scalpel can shorten the surgical time. (author)

Renal contrast-enhanced MR angiography: timing errors and accurate depiction of renal artery origins.

Science.gov (United States)

Schmidt, Maria A; Morgan, Robert

2008-10-01

To investigate bolus timing artifacts that impair depiction of renal arteries at contrast material-enhanced magnetic resonance (MR) angiography and to determine the effect of contrast agent infusion rates on artifact generation. Renal contrast-enhanced MR angiography was simulated for a variety of infusion schemes, assuming both correct and incorrect timing between data acquisition and contrast agent injection. In addition, the ethics committee approved the retrospective evaluation of clinical breath-hold renal contrast-enhanced MR angiographic studies obtained with automated detection of contrast agent arrival. Twenty-two studies were evaluated for their ability to depict the origin of renal arteries in patent vessels and for any signs of timing errors. Simulations showed that a completely artifactual stenosis or an artifactual overestimation of an existing stenosis at the renal artery origin can be caused by timing errors of the order of 5 seconds in examinations performed with contrast agent infusion rates compatible with or higher than those of hand injections. Lower infusion rates make the studies more likely to accurately depict the origin of the renal arteries. In approximately one-third of all clinical examinations, different contrast agent uptake rates were detected on the left and right sides of the body, and thus allowed us to confirm that it is often impossible to optimize depiction of both renal arteries. In three renal arteries, a signal void was found at the origin in a patent vessel, and delayed contrast agent arrival was confirmed. Computer simulations and clinical examinations showed that timing errors impair the accurate depiction of renal artery origins. (c) RSNA, 2008.

Short linear shadows connecting pulmonary segmental arteries to oblique fissures in volumetric thin-section CT images: comparing CT, micro-CT and histopathology

International Nuclear Information System (INIS)

Guan, Chun-Shuang; Ma, Da-Qing; Chen, Jiang-Hong; Chen, Bu-Dong; Cui, Dun; Zhang, Yan-Song; Liu, Wei-Hua

2016-01-01

To retrospectively evaluate short linear shadows connecting pulmonary segmental arteries to oblique fissures in thin-section CT images and determine their anatomical basis. CT scanning was performed on 108 patients and 11 lung specimens with no lung diseases around the oblique fissures or hilar. Two radiologists evaluated the imaging. The parameters included length, thickness of short linear shadows, pulmonary segmental artery variations, and traction interlobar fissures, etc. The short linear shadows were not related to sex, age, or smoking history. The lengths of the short linear shadows were generally within 10 mm. The thicknesses of the short linear shadows ranged from 1 to 2 mm. Of the patients, 26.9 % showed pulmonary segmental artery variations; 66.7 % of short linear shadows pulled oblique fissures. In three-dimensional images, the short linear shadows appeared as arc planes, with one side edge connected to the oblique fissure, one side edge connected to a pulmonary segmental artery. On the tissue slices, the short linear shadow exhibited a band structure composed of connective tissues, small blood vessels, and small lymphatic vessels. Short linear shadows are a type of normal intrapulmonary membranes and can maintain the integrity of the oblique fissures and hilar structure. (orig.)

Real-time three-dimensional ultrasound-assisted axillary plexus block defines soft tissue planes.

Science.gov (United States)

Clendenen, Steven R; Riutort, Kevin; Ladlie, Beth L; Robards, Christopher; Franco, Carlo D; Greengrass, Roy A

2009-04-01

Two-dimensional (2D) ultrasound is commonly used for regional block of the axillary brachial plexus. In this technical case report, we described a real-time three-dimensional (3D) ultrasound-guided axillary block. The difference between 2D and 3D ultrasound is similar to the difference between plain radiograph and computer tomography. Unlike 2D ultrasound that captures a planar image, 3D ultrasound technology acquires a 3D volume of information that enables multiple planes of view by manipulating the image without movement of the ultrasound probe. Observation of the brachial plexus in cross-section demonstrated distinct linear hyperechoic tissue structures (loose connective tissue) that initially inhibited the flow of the local anesthesia. After completion of the injection, we were able to visualize the influence of arterial pulsation on the spread of the local anesthesia. Possible advantages of this novel technology over current 2D methods are wider image volume and the capability to manipulate the planes of the image without moving the probe.

The kunitz protease inhibitor domain of protease nexin-2 inhibits factor XIa and murine carotid artery and middle cerebral artery thrombosis

Science.gov (United States)

Wu, Wenman; Li, Hongbo; Navaneetham, Duraiswamy; Reichenbach, Zachary W.; Tuma, Ronald F.

2012-01-01

Coagulation factor XI (FXI) plays an important part in both venous and arterial thrombosis, rendering FXIa a potential target for the development of antithrombotic therapy. The kunitz protease inhibitor (KPI) domain of protease nexin-2 (PN2) is a potent, highly specific inhibitor of FXIa, suggesting its possible role in the inhibition of FXI-dependent thrombosis in vivo. Therefore, we examined the effect of PN2KPI on thrombosis in the murine carotid artery and the middle cerebral artery. Intravenous administration of PN2KPI prolonged the clotting time of both human and murine plasma, and PN2KPI inhibited FXIa activity in both human and murine plasma in vitro. The intravenous administration of PN2KPI into WT mice dramatically decreased the progress of FeCl3-induced thrombus formation in the carotid artery. After a similar initial rate of thrombus formation with and without PN2KPI treatment, the propagation of thrombus formation after 10 minutes and the amount of thrombus formed were significantly decreased in mice treated with PN2KPI injection compared with untreated mice. In the middle cerebral artery occlusion model, the volume and fraction of ischemic brain tissue were significantly decreased in PN2KPI-treated compared with untreated mice. Thus, inhibition of FXIa by PN2KPI is a promising approach to antithrombotic therapy. PMID:22674803

Three-dimensional whole-brain perfusion quantification using pseudo-continuous arterial spin labeling MRI at multiple post-labeling delays: accounting for both arterial transit time and impulse response function.

Science.gov (United States)

Qin, Qin; Huang, Alan J; Hua, Jun; Desmond, John E; Stevens, Robert D; van Zijl, Peter C M

2014-02-01

Measurement of the cerebral blood flow (CBF) with whole-brain coverage is challenging in terms of both acquisition and quantitative analysis. In order to fit arterial spin labeling-based perfusion kinetic curves, an empirical three-parameter model which characterizes the effective impulse response function (IRF) is introduced, which allows the determination of CBF, the arterial transit time (ATT) and T(1,eff). The accuracy and precision of the proposed model were compared with those of more complicated models with four or five parameters through Monte Carlo simulations. Pseudo-continuous arterial spin labeling images were acquired on a clinical 3-T scanner in 10 normal volunteers using a three-dimensional multi-shot gradient and spin echo scheme at multiple post-labeling delays to sample the kinetic curves. Voxel-wise fitting was performed using the three-parameter model and other models that contain two, four or five unknown parameters. For the two-parameter model, T(1,eff) values close to tissue and blood were assumed separately. Standard statistical analysis was conducted to compare these fitting models in various brain regions. The fitted results indicated that: (i) the estimated CBF values using the two-parameter model show appreciable dependence on the assumed T(1,eff) values; (ii) the proposed three-parameter model achieves the optimal balance between the goodness of fit and model complexity when compared among the models with explicit IRF fitting; (iii) both the two-parameter model using fixed blood T1 values for T(1,eff) and the three-parameter model provide reasonable fitting results. Using the proposed three-parameter model, the estimated CBF (46 ± 14 mL/100 g/min) and ATT (1.4 ± 0.3 s) values averaged from different brain regions are close to the literature reports; the estimated T(1,eff) values (1.9 ± 0.4 s) are higher than the tissue T1 values, possibly reflecting a contribution from the microvascular arterial blood compartment

Is epicardial adipose tissue, assessed by echocardiography, a reliable method for visceral adipose tissue prediction?

Science.gov (United States)

Silaghi, Alina Cristina; Poantă, Laura; Valea, Ana; Pais, Raluca; Silaghi, Horatiu

2011-03-01

Epicardial adipose tissue is an ectopic fat storage at the heart surface in direct contact with the coronary arteries. It is considered a metabolically active tissue, being a local source of pro-inflammatory factors that contribute to the pathogenesis of coronary artery disease. The AIM of our study was to establish correlations between echocardiographic assessment of epicardial adipose tissue and anthropometric and ultrasound measurements of the central and peripheral fat depots. The study was conducted on 22 patients with or without coronaropathy. Epicardial adipose tissue was measured using Aloka Prosound α 10 machine with a 3.5-7.5 MHz variable-frequency transducer and subcutaneous and visceral fat with Esaote Megas GPX machine and 3.5-7.5 MHz variable frequency transducer. Epicardial adipose tissue measured by echocardiography is correlated with waist circumference (p < 0.05), visceral adipose tissue thickness measured by ultrasonography (US) and is not correlated with body mass index (p = 0.315), hip and thigh circumference or subcutaneous fat thickness measured by US. Our study confirms that US assessment of epicardial fat correlates with anthropometric and US measurements of the central fat, representing an indirect but reliable marker of the visceral fat.

Integrated Detection and Prediction of Influenza Activity for Real-Time Surveillance: Algorithm Design.

Science.gov (United States)

Spreco, Armin; Eriksson, Olle; Dahlström, Örjan; Cowling, Benjamin John; Timpka, Toomas

2017-06-15

Influenza is a viral respiratory disease capable of causing epidemics that represent a threat to communities worldwide. The rapidly growing availability of electronic "big data" from diagnostic and prediagnostic sources in health care and public health settings permits advance of a new generation of methods for local detection and prediction of winter influenza seasons and influenza pandemics. The aim of this study was to present a method for integrated detection and prediction of influenza virus activity in local settings using electronically available surveillance data and to evaluate its performance by retrospective application on authentic data from a Swedish county. An integrated detection and prediction method was formally defined based on a design rationale for influenza detection and prediction methods adapted for local surveillance. The novel method was retrospectively applied on data from the winter influenza season 2008-09 in a Swedish county (population 445,000). Outcome data represented individuals who met a clinical case definition for influenza (based on International Classification of Diseases version 10 [ICD-10] codes) from an electronic health data repository. Information from calls to a telenursing service in the county was used as syndromic data source. The novel integrated detection and prediction method is based on nonmechanistic statistical models and is designed for integration in local health information systems. The method is divided into separate modules for detection and prediction of local influenza virus activity. The function of the detection module is to alert for an upcoming period of increased load of influenza cases on local health care (using influenza-diagnosis data), whereas the function of the prediction module is to predict the timing of the activity peak (using syndromic data) and its intensity (using influenza-diagnosis data). For detection modeling, exponential regression was used based on the assumption that the beginning

A new graphic plot analysis for determination of neuroreceptor binding in positron emission tomography studies.

Science.gov (United States)

Ito, Hiroshi; Yokoi, Takashi; Ikoma, Yoko; Shidahara, Miho; Seki, Chie; Naganawa, Mika; Takahashi, Hidehiko; Takano, Harumasa; Kimura, Yuichi; Ichise, Masanori; Suhara, Tetsuya

2010-01-01

In positron emission tomography (PET) studies with radioligands for neuroreceptors, tracer kinetics have been described by the standard two-tissue compartment model that includes the compartments of nondisplaceable binding and specific binding to receptors. In the present study, we have developed a new graphic plot analysis to determine the total distribution volume (V(T)) and nondisplaceable distribution volume (V(ND)) independently, and therefore the binding potential (BP(ND)). In this plot, Y(t) is the ratio of brain tissue activity to time-integrated arterial input function, and X(t) is the ratio of time-integrated brain tissue activity to time-integrated arterial input function. The x-intercept of linear regression of the plots for early phase represents V(ND), and the x-intercept of linear regression of the plots for delayed phase after the equilibrium time represents V(T). BP(ND) can be calculated by BP(ND)=V(T)/V(ND)-1. Dynamic PET scanning with measurement of arterial input function was performed on six healthy men after intravenous rapid bolus injection of [(11)C]FLB457. The plot yielded a curve in regions with specific binding while it yielded a straight line through all plot data in regions with no specific binding. V(ND), V(T), and BP(ND) values calculated by the present method were in good agreement with those by conventional non-linear least-squares fitting procedure. This method can be used to distinguish graphically whether the radioligand binding includes specific binding or not.

Functional real-time optoacoustic imaging of middle cerebral artery occlusion in mice.

Directory of Open Access Journals (Sweden)

Moritz Kneipp

Full Text Available BACKGROUND AND PURPOSE: Longitudinal functional imaging studies of stroke are key in identifying the disease progression and possible therapeutic interventions. Here we investigate the applicability of real-time functional optoacoustic imaging for monitoring of stroke progression in the whole brain of living animals. MATERIALS AND METHODS: The middle cerebral artery occlusion (MCAO was used to model stroke in mice, which were imaged preoperatively and the occlusion was kept in place for 60 minutes, after which optoacoustic scans were taken at several time points. RESULTS: Post ischemia an asymmetry of deoxygenated hemoglobin in the brain was observed as a region of hypoxia in the hemisphere affected by the ischemic event. Furthermore, we were able to visualize the penumbra in-vivo as a localized hemodynamically-compromised area adjacent to the region of stroke-induced perfusion deficit. CONCLUSION: The intrinsic sensitivity of the new imaging approach to functional blood parameters, in combination with real time operation and high spatial resolution in deep living tissues, may see it become a valuable and unique tool in the development and monitoring of treatments aimed at suspending the spread of an infarct area.

Multi-modal assessment of neurovascular coupling during cerebral ischaemia and reperfusion using remote middle cerebral artery occlusion

DEFF Research Database (Denmark)

Sutherland, Brad A; Fordsmann, Jonas C; Martin, Chris

2017-01-01

. Male Wistar rats were subjected to remote middle cerebral artery occlusion, where a long filament was advanced intraluminally through a guide cannula in the common carotid artery. Transcallosal stimulation evoked increases in blood flow, tissue oxygenation and neuronal activity, which were diminished...... that neurovascular dysfunction was not sustained. These data show for the first time that the rat remote middle cerebral artery occlusion model coupled with transcallosal stimulation provides a novel method for continuous assessment of hyperacute neurovascular coupling changes during ischaemia and reperfusion......Hyperacute changes in cerebral blood flow during cerebral ischaemia and reperfusion are important determinants of injury. Cerebral blood flow is regulated by neurovascular coupling, and disruption of neurovascular coupling contributes to brain plasticity and repair problems. However, it is unknown...

Connective tissue integrity is lost in vitamin B-6-deficient chicks

Science.gov (United States)

Masse, P. G.; Yamauchi, M.; Mahuren, J. D.; Coburn, S. P.; Muniz, O. E.; Howell, D. S.

1995-01-01

The objective of the present investigation was to characterize further the connective tissue disorder produced by pyridoxine (vitamin B-6) deficiency, as previously evidenced by electron microscopy. Following the second post-natal week, fast growing male chicks were deprived of pyridoxine for a 1-mo period. Six weeks post-natally, blood concentrations in the experimental deficiency group had declined to deficiency levels as registered by low concentrations of pyridoxal phosphate (coenzyme form) in erythrocytes, but did not reach levels associated with neurological symptoms. Light microscopic study showed abnormalities in the extracellular matrix of the connective tissues. Collagen cross-links and the aldehyde contents were not significantly lower in cartilage and tendon collagens of vitamin B-6-deficient animals than in age-matched controls; also, their proteoglycan degrading protease and collagenase activities measured in articular cartilages were not greater. Thus, proteolysis was an unlikely alternative mechanism to account for the loss of connective tissue integrity. These results point to the need for further investigation into adhesive properties of collagen associated proteoglycans or other proteins in vitamin B-6-deficient connective tissue.

Effect of implanted radioactive 125I seeds on normal tissue structures of bronchus, esophagus, pulmonary artery, pulmonary vein and alveolus in dogs

International Nuclear Information System (INIS)

Qi Liangchen; Han Zhenguo; Yang Bin; Heersitai

2008-01-01

Objective: To investigate the effect of implanted radioactive 125 I seeds on normal tissue structures of bronchus, esophagus, pulmonary artery, pulmonary vein and alveolus in dogs. Methods: Nine healthy male dogs weighing 17-21 kg were randomly divided into three groups: 30 d, 60 d experimental groups and control group. Radioactive 125 I seeds (3.7 x 10 7 Bg, 1.0 mCi) were implanted into the sides of bronchus, esophagus, pulmonary artery, pulmonary vein respectively, the samples of bronchus, esophagus, pulmonary artery, pulmonary vein were taken 30 and 60 d after transplantation, HE staining was used to observe the pathologic changes of the tissues under light microscope. Results: The damages of normal bronchus, esophagus, pulmonary artery, pulmonary vein and alveolus after radioactive 125 I seeds implantation in 30 d group were weaker than those in control group and 60 d group, there were no complications such as perforation, hemorrhage, necrosis, etc. Histopathological score indicated that the scores of bronchus, esophagus and alveolar in 30 d group and 60 d group were higher than those in control group (P 0.05); there was no significant difference in histopathological score of pulmonary vein among all groups (P>0.05). Conclusion: The implanted radioactive 125 I seeds can damage all kinds of tissues at different degrees, but this kind of damage is reversible, the dog may repair the damage through its own repair ability, its clinical application is safe. (authors)

Time-specific measurements of energy deposition from radiation fields in simulated sub-micron tissue volumes

International Nuclear Information System (INIS)

Famiano, M.A.

1997-01-01

A tissue-equivalent spherical proportional counter is used with a modified amplifier system to measure specific energy deposited from a uniform radiation field for short periods of time (∼1 micros to seconds) in order to extrapolate to dose in sub-micron tissue volumes. The energy deposited during these time intervals is compared to biological repair processes occurring within the same intervals after the initial energy deposition. The signal is integrated over a variable collection time which is adjusted with a square-wave pulse. Charge from particle passages is collected on the anode during the period in which the integrator is triggered, and the signal decays quickly to zero after the integrator feedback switch resets; the process repeats for every triggering pulse. Measurements of energy deposited from x rays, 137 Cs gamma rays, and electrons from a 90 Sr/ 90 Y source for various time intervals are taken. Spectral characteristics as a function of charge collection time are observed and frequency plots of specific energy and collection time-interval are presented. In addition, a threshold energy flux is selected for each radiation type at which the formation of radicals (based on current measurements) in mammalian cells equals the rate at which radicals are repaired

C-14-activity incorporation into the protein of fetal organs of guinea pigs with different maternal placental blood flow and fetal arterial O2-saturation

International Nuclear Information System (INIS)

Duenzl, B.

1981-01-01

In anaesthesised gravid guinea-pigs the dilate, end section of a placental radial artery was connected to the A.carotis via a flow meter and a throttle in order to measure and widely alter the maternal placental blood flow. Blood samples are taken from the fetal A.carotis, the fetal arterial O 2 -saturation and the Hb-content were determined. By altering the maternal placental blood circulation the fetal arterial O 2 -concentration can stabilised at various levels. In order to study the protein synthesis, under these conditions one infused 185 kBq C-14-leucine over a period of 3 hours into the jugular vein of the fetus. During infusion the radioactive concentrations in whole plasma and plasma water were measured. After the infusion the radioactive concentrations in the tissue fluid, the intracellular fluid and the acid-insoluble tissue fraction (protein) of the heart, kidenys, liver, the muscles of the upper end lower part of the body, the brain and the placenta were measured. The following deductions were drawn from the findings: The maternal placental blood flow vitally influences the activity incorporation per activity concentration in the plasma water. These findings agree with the hypotheses that the maternal blood circulation has an essential influence on the fetal proteins synthesis and that this influence can be attributed to the connection between placenta connection blood flow and oxygen saturation of fetal arterial blood. (orig.) [de

A Trifunctional, Modular Biomaterial Coating : Nonadhesive to Bacteria, Chlorhexidine-Releasing and Tissue-Integrating

NARCIS (Netherlands)

Sjollema, Jelmer; Keul, Heidrun; van der Mei, Henny; Dijkstra, Rene; Rustema-Abbing, Minie; de Vries, Joop; Loontjens, Ton; Dirks, Ton; Busscher, Henk

Various potential anti-infection strategies can be thought of for biomaterial implants and devices. Permanent, tissue-integrated implants such as artificial joint prostheses require a different anti-infection strategy than, for instance, removable urinary catheters. The different requirements set to

Endotoxin induction of an inhibitor of plasminogen activator in bovine pulmonary artery endothelial cells

Energy Technology Data Exchange (ETDEWEB)

1986-01-05

The effects of bacterial lipopolysaccharide (endotoxin) on the fibrinolytic activity of bovine pulmonary artery endothelial cells were examined. Endotoxin suppressed the net fibrinolytic activity of cell extracts and conditioned media in a dose-dependent manner. The effects of endotoxin required at least 6 h for expression. Cell extracts and conditioned media contained a 44-kDa urokinase-like plasminogen activator. Media also contained multiple plasminogen activators with molecular masses of 65-75 and 80-100 kDa. Plasminogen activators in extracts and media were unchanged by treatment of cells with endotoxin. Diisopropyl fluorophosphate (DFP)-abolished fibrinolytic activity of extracts and conditioned media. DFP-treated samples from endotoxin-treated but not untreated cells inhibited urokinase and tissue plasminogen activator, but not plasmin. Inhibitory activity was lost by incubation at pH 3 or heating to 56/sup 0/C for 10 min. These treatments did not affect inhibitory activity of fetal bovine serum. Incubation of /sup 125/I-urokinase with DFP-treated medium from endotoxin-treated cells produced an inactive complex with an apparent molecular mass of 80-85 kDa.

Superselective intra-arterial infusion via the superficial temporal artery and occipital artery for gingival carcinoma of the mandible. Simultaneous catheter placement to the maxillary artery and facial artery

International Nuclear Information System (INIS)

Iwai, Toshinori; Mitsudo, Kenji; Fukui, Takafumi

2009-01-01

Superselective intra-arterial infusion via the superficial temporal artery (STA) has become useful for oral cancer. Approaching via the occipital artery (OA) enables superselective intra-arterial infusion when catheter placement via the STA is impossible. Therefore, simultaneous catheter placement via the STA and OA is possible. We report a surgical method of simultaneous catheter placement via the STA and OA to achieve retrograde superselective intra-arterial infusion for gingival carcinoma of the mandible. Preoperatively, three-dimensional computed tomography angiography was performed to identify the route of the external carotid artery and branches such as the STA, OA, maxillary artery, and facial artery (FA). Thirteen patients with mandibular gingival cancer underwent catheter placement via the STA and OA under local anesthesia. Catheter placement via the STA and OA was superselectively successful in all the patients. The mean operating time was 150.8 min. Catheter placed to the FA via the OA was dislocated during the treatment in one patient, and so the catheter was replaced. This method is useful to enable superselective intra-arterial chemotherapy to the whole gingival carcinoma of the mandible from the start of treatment compared with approaching via the STA. (author)

[Correlation between EGLN1 gene, protein express in lung tissue of rats and pulmonary artery pressure at different altitude].

Science.gov (United States)

Li, S H; Li, S; Sun, L; Bai, Z Z; Yang, Q Y; Ga, Q; Jin, G E

2016-08-23

To investigate the correlation between pulmonary artery pressure (PAP) and the expression level of Egl nine homologue 1 (EGLN1) gene or its protein in lung tissue of rats at different altitudes. Totally 121 male Wistar rats were randomly divided into low altitude group (n=11), moderate altitude group and high altitude group, the rats in moderate altitude and high altitude group were further divided into 1(st) day, 3(rd) days, 7(th) days, 15(th) day and 30(th) day group according to the exposure time to hypoxic environment, each group 11 rats. The low altitude group, the PAP of rats were determined by physiological signal acquisition system, and tissue samples were collected in liquid nitrogen container for storage at an altitude of 498 m area. Moderate altitude group rats were placed in altitude of 2 260 meters of natural environment, 5 high altitude groups rats were placed in the hypobaric hypoxic chamber, simulating altitude of 4 500 meters. The PAP of rats in moderate altitude group and high altitude group were also determined by physiological signal acquisition system, and tissue samples were collected when rats were exposed to hypoxia at 1(st), 3(rd), 7(th), 15(th) and 30(th) day; Western blot was used to determine expression levels of EGLN1 protein, and person correlation analysis was used to analyze whether the protein was related to the formation of pulmonary arterial hypertension (PH) under hypoxia. Real-time quantitive PCR method determined expression levels of EGLN1 mRNA in lung tissues, and the relative expression method was used to analyze PCR data, and finally assess whether the EGLN1 gene was the initial cause of the formation of PH during hypoxia. The mean PAP of rats was (20.0±3.2) mmHg (1 mmHg=0.133 kPa) in low altitude group; in moderate altitude group, mean PAP began to increase slightly when rats were exposed to hypoxia on the 15(th) day and reached at (22.7±4.1) mmHg on hypoxic 30(th) day, but compared with the low altitude group, there was

Placental vascular responses are dependent on surrounding tissue

DEFF Research Database (Denmark)

Brøgger, Torbjørn Halle

. Materials and methods. From fresh born placentas, stem villi arteries were carefully dissected. The artery branches were divided. The surrounding tissue was removed from one end and was left untouched in the other end.Then, using wire myography, they were investigated in terms of contractility...... and sensitivity to physiological relevant human-like agonists. Results. Sensitivity to PGF2α, Tx-analog, 5-HT and endothelin-1 was significantly lower in arteries with intact surrounding tissue compared to arteries stripped of the tissue. The maximal force development was also significantly lower in arteries...... with surrounding tissue when they were depolarized high extracellular [K+] or stimulated with PGF2α or endotheline-1. Conclusion. The perivascular tissue significantly alters stem villi arteries' sensitivity and force development in a suppressive way. This implicates a new aspect of blood flow regulation...

Long Pulse Integrator of Variable Integral Time Constant

International Nuclear Information System (INIS)

Wang Yong; Ji Zhenshan; Du Xiaoying; Wu Yichun; Li Shi; Luo Jiarong

2010-01-01

A kind of new long pulse integrator was designed based on the method of variable integral time constant and deducting integral drift by drift slope. The integral time constant can be changed by choosing different integral resistors, in order to improve the signal-to-noise ratio, and avoid output saturation; the slope of integral drift of a certain period of time can be calculated by digital signal processing, which can be used to deduct the drift of original integral signal in real time to reduce the integral drift. The tests show that this kind of long pulse integrator is good at reducing integral drift, which also can eliminate the effects of changing integral time constant. According to experiments, the integral time constant can be changed by remote control and manual adjustment of integral drift is avoided, which can improve the experiment efficiency greatly and can be used for electromagnetic measurement in Tokamak experiment. (authors)

Differentially expressed genes in embryonic cardiac tissues of mice lacking Folr1 gene activity

Directory of Open Access Journals (Sweden)

Schwartz Robert J

2007-11-01

Full Text Available Abstract Background Heart anomalies are the most frequently observed among all human congenital defects. As with the situation for neural tube defects (NTDs, it has been demonstrated that women who use multivitamins containing folic acid peri-conceptionally have a reduced risk for delivering offspring with conotruncal heart defects 123. Cellular folate transport is mediated by a receptor or binding protein and by an anionic transporter protein system. Defective function of the Folr1 (also known as Folbp1; homologue of human FRα gene in mice results in inadequate transport, accumulation, or metabolism of folate during cardiovascular morphogenesis. Results We have observed cardiovascular abnormalities including outflow tract and aortic arch arterial defects in genetically compromised Folr1 knockout mice. In order to investigate the molecular mechanisms underlying the failure to complete development of outflow tract and aortic arch arteries in the Folr1 knockout mouse model, we examined tissue-specific gene expression difference between Folr1 nullizygous embryos and morphologically normal heterozygous embryos during early cardiac development (14-somite stage, heart tube looping (28-somite stage, and outflow track septation (38-somite stage. Microarray analysis was performed as a primary screening, followed by investigation using quantitative real-time PCR assays. Gene ontology analysis highlighted the following ontology groups: cell migration, cell motility and localization of cells, structural constituent of cytoskeleton, cell-cell adhesion, oxidoreductase, protein folding and mRNA processing. This study provided preliminary data and suggested potential candidate genes for further description and investigation. Conclusion The results suggested that Folr1 gene ablation and abnormal folate homeostasis altered gene expression in developing heart and conotruncal tissues. These changes affected normal cytoskeleton structures, cell migration and

Validation and augmentation of Inrix arterial travel time data using independent sources : [research summary].

Science.gov (United States)

2015-02-01

Although the freeway travel time data has been validated extensively in recent : years, the quality of arterial travel time data is not well known. This project : presents a comprehensive validation scheme for arterial travel time data based : on GPS...

A curve-fitting approach to estimate the arterial plasma input function for the assessment of glucose metabolic rate and response to treatment.

NARCIS (Netherlands)

Vriens, D.; Geus-Oei, L.F. de; Oyen, W.J.G.; Visser, E.P.

2009-01-01

For the quantification of dynamic (18)F-FDG PET studies, the arterial plasma time-activity concentration curve (APTAC) needs to be available. This can be obtained using serial sampling of arterial blood or an image-derived input function (IDIF). Arterial sampling is invasive and often not feasible

High arterial compliance in cirrhosis is related to low adrenaline and elevated circulating calcitonin gene related peptide but not to activated vasoconstrictor systems

DEFF Research Database (Denmark)

Henriksen, Jens Henrik Sahl; Møller, S; Schifter, S

2001-01-01

catecholamines, renin activity, endothelin-1, and calcitonin gene related peptide (CGRP) at baseline and during oxygen inhalation. RESULTS: COMP(art) was significantly increased in cirrhotic patients compared with controls (1.32 v 1.06 ml/mm Hg; padrenaline levels (r=-0.......001) and central circulation time (r=-0.49; padrenaline (-16%; p... to COMP(art) disappeared. The relation of COMP(art) to CGRP and circulatory variables remained unchanged. CONCLUSION: Elevated arterial compliance in cirrhosis is related to low adrenaline, high CGRP, and systemic hyperdynamics but not to indicators of the activated vasoconstrictor systems (noradrenaline...

Real-time ultrasound-tagging to track the 2D motion of the common carotid artery wall in vivo

Energy Technology Data Exchange (ETDEWEB)

Zahnd, Guillaume, E-mail: g.zahnd@erasmusmc.nl [Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus MC, Rotterdam 3000 CA (Netherlands); Salles, Sébastien; Liebgott, Hervé; Vray, Didier [Université de Lyon, CREATIS, CNRS UMR 5220, INSERM U1044, INSA-Lyon, Université Lyon 1, Lyon 69100 (France); Sérusclat, André [Department of Radiology, Louis Pradel Hospital, Lyon 69500 (France); Moulin, Philippe [Department of Endocrinology, Louis Pradel Hospital, Hospices Civils de Lyon, Université Lyon 1, Lyon 69100, France and INSERM UMR 1060, Lyon 69500 (France)

2015-02-15

Purpose: Tracking the motion of biological tissues represents an important issue in the field of medical ultrasound imaging. However, the longitudinal component of the motion (i.e., perpendicular to the beam axis) remains more challenging to extract due to the rather coarse resolution cell of ultrasound scanners along this direction. The aim of this study is to introduce a real-time beamforming strategy dedicated to acquire tagged images featuring a distinct pattern in the objective to ease the tracking. Methods: Under the conditions of the Fraunhofer approximation, a specific apodization function was applied to the received raw channel data, in real-time during image acquisition, in order to introduce a periodic oscillations pattern along the longitudinal direction of the radio frequency signal. Analytic signals were then extracted from the tagged images, and subpixel motion tracking of the intima–media complex was subsequently performed offline, by means of a previously introduced bidimensional analytic phase-based estimator. Results: The authors’ framework was applied in vivo on the common carotid artery from 20 young healthy volunteers and 6 elderly patients with high atherosclerosis risk. Cine-loops of tagged images were acquired during three cardiac cycles. Evaluated against reference trajectories manually generated by three experienced analysts, the mean absolute tracking error was 98 ± 84 μm and 55 ± 44 μm in the longitudinal and axial directions, respectively. These errors corresponded to 28% ± 23% and 13% ± 9% of the longitudinal and axial amplitude of the assessed motion, respectively. Conclusions: The proposed framework enables tagged ultrasound images of in vivo tissues to be acquired in real-time. Such unconventional beamforming strategy contributes to improve tracking accuracy and could potentially benefit to the interpretation and diagnosis of biomedical images.

Mast cells in atherosclerotic cardiovascular disease - Activators and actions.

Science.gov (United States)

Kovanen, Petri T; Bot, Ilze

2017-12-05

Mast cells are potent actors involved in inflammatory reactions in various tissues, including both in the intimal and the adventitial layers of atherosclerotic arteries. In the arterial intima, the site of atherogenesis, mast cells are activated to degranulate, and thereby triggered to release an abundance of preformed inflammatory mediators, notably histamine, heparin, neutral proteases and cytokines stored in their cytoplasmic secretory granules. Depending on the stimulus, mast cell activation may also launch prolonged synthesis and secretion of single bioactive molecules, such as cytokines and derivatives of arachidonic acid. The mast cell-derived mediators may impede the functions of different types of cells present in atherosclerotic lesions, and also compromise the structural and functional integrity of the intimal extracellular matrix. In the adventitial layer of atherosclerotic coronary arteries, mast cells locate next to peptidergic sensory nerve fibers, which, by releasing neuropeptides may activate mast cells to release vasoactive compounds capable of triggering local vasoconstriction. The concerted actions of arterial mast cells have the potential to contribute to the initiation and progression of atherosclerosis, and ultimately to destabilization and rupture of an advanced atherosclerotic plaque with ensuing atherothrombotic complications. Copyright © 2017 Elsevier B.V. All rights reserved.

A microRNA activity map of human mesenchymal tumors: connections to oncogenic pathways; an integrative transcriptomic study

Directory of Open Access Journals (Sweden)

Fountzilas Elena

2012-07-01

Full Text Available Abstract Background MicroRNAs (miRNAs are nucleic acid regulators of many human mRNAs, and are associated with many tumorigenic processes. miRNA expression levels have been used in profiling studies, but some evidence suggests that expression levels do not fully capture miRNA regulatory activity. In this study we integrate multiple gene expression datasets to determine miRNA activity patterns associated with cancer phenotypes and oncogenic pathways in mesenchymal tumors – a very heterogeneous class of malignancies. Results Using a computational method, we identified differentially activated miRNAs between 77 normal tissue specimens and 135 sarcomas and we validated many of these findings with microarray interrogation of an independent, paraffin-based cohort of 18 tumors. We also showed that miRNA activity is imperfectly correlated with miRNA expression levels. Using next-generation miRNA sequencing we identified potential base sequence alterations which may explain differential activity. We then analyzed miRNA activity changes related to the RAS-pathway and found 21 miRNAs that switch from silenced to activated status in parallel with RAS activation. Importantly, nearly half of these 21 miRNAs were predicted to regulate integral parts of the miRNA processing machinery, and our gene expression analysis revealed significant reductions of these transcripts in RAS-active tumors. These results suggest an association between RAS signaling and miRNA processing in which miRNAs may attenuate their own biogenesis. Conclusions Our study represents the first gene expression-based investigation of miRNA regulatory activity in human sarcomas, and our findings indicate that miRNA activity patterns derived from integrated transcriptomic data are reproducible and biologically informative in cancer. We identified an association between RAS signaling and miRNA processing, and demonstrated sequence alterations as plausible causes for differential miRNA activity

Integration of a capacitive pressure sensing system into the outer catheter wall for coronary artery FFR measurements

Science.gov (United States)

Stam, Frank; Kuisma, Heikki; Gao, Feng; Saarilahti, Jaakko; Gomes Martins, David; Kärkkäinen, Anu; Marrinan, Brendan; Pintal, Sebastian

2017-05-01

The deadliest disease in the world is coronary artery disease (CAD), which is related to a narrowing (stenosis) of blood vessels due to fatty deposits, plaque, on the arterial walls. The level of stenosis in the coronary arteries can be assessed by Fractional Flow Reserve (FFR) measurements. This involves determining the ratio between the maximum achievable blood flow in a diseased coronary artery and the theoretical maximum flow in a normal coronary artery. The blood flow is represented by a pressure drop, thus a pressure wire or pressure sensor integrated in a catheter can be used to calculate the ratio between the coronary pressure distal to the stenosis and the normal coronary pressure. A 2 Fr (0.67mm) outer diameter catheter was used, which required a high level of microelectronics miniaturisation to fit a pressure sensing system into the outer wall. The catheter has an eccentric guidewire lumen with a diameter of 0.43mm, which implies that the thickest catheter wall section provides less than 210 microns height for flex assembly integration consisting of two dies, a capacitive MEMS pressure sensor and an ASIC. In order to achieve this a very thin circuit flex was used, and the two chips were thinned down to 75 microns and flip chip mounted face down on the flex. Many challenges were involved in obtaining a flex layout that could wrap into a small tube without getting the dies damaged, while still maintaining enough flexibility for the catheter to navigate the arterial system.

Physical Activity and Characteristics of the Carotid Artery Wall in High-Risk Patients-The SMART (Second Manifestations of Arterial Disease) Study.

Science.gov (United States)

Boss, H Myrthe; van der Graaf, Yolanda; Visseren, Frank L J; Van den Berg-Vos, Renske M; Bots, Michiel L; de Borst, Gert Jan; Cramer, Maarten J; Kappelle, L Jaap; Geerlings, Mirjam I

2017-07-23

Physical activity reduces the risk of vascular disease. This benefit is not entirely explained through an effect on vascular risk factors. We examined the relationship of physical activity and characteristics of the carotid artery wall in patients with vascular disease or risk factors. Cross-sectional analyses were performed in 9578 patients from the SMART (Second Manifestations of Arterial Disease) study, a prospective cohort study among patients with vascular disease or risk factors. Physical activity was assessed using questionnaires. Carotid intima-media thickness and carotid artery stenosis of both common carotid arteries was measured. In a subset of 3165 participants carotid diastolic diameter and distension were assessed. Carotid stiffness was expressed as the distensibility coefficient and Young's elastic modulus. Regression analyses adjusted for vascular risk factors showed that physical activity was inversely associated with diastolic diameter (fifth versus first quintile B=-0.13 mm; 95% CI, -0.21 to -0.05) and decreased risk of carotid artery stenosis (relative risk, 0.58; 95% CI, 0.48-0.69). A light level of physical activity was associated with less carotid stiffness (second versus first quintile; Young's elastic modulus B=-0.11 kPa -1 ×10 -3 ; 95% CI, -0.16 to -0.06; distensibility coefficient B=0.93 kPa×10 3 ; 95% CI, 0.34-1.51), but there was no additional benefit with increasing levels of physical activity. In patients with vascular disease, physical activity was inversely associated with common carotid intima-media thickness, but not in patients with vascular risk factors. In patients with vascular disease or risk factors, increased physical activity was associated with smaller carotid diastolic diameter, decreased risk of carotid artery stenosis, and less carotid stiffness, but it only showed benefits on carotid intima-media thickness in patients with vascular disease. © 2017 The Authors. Published on behalf of the American Heart

Assessment of post-implantation integration of engineered tissues using fluorescence lifetime spectroscopy

Science.gov (United States)

Elahi, Sakib F.; Lee, Seung Y.; Lloyd, William R.; Chen, Leng-Chun; Kuo, Shiuhyang; Zhou, Ying; Kim, Hyungjin M.; Kennedy, Robert; Marcelo, Cynthia; Feinberg, Stephen E.; Mycek, Mary-Ann

2018-02-01

Clinical translation of engineered tissue constructs requires noninvasive methods to assess construct health and viability after implantation in patients. However, current practices to monitor post-implantation construct integration are either qualitative (visual assessment) or destructive (tissue histology). As label-free fluorescence lifetime sensing can noninvasively characterize pre-implantation construct viability, we employed a handheld fluorescence lifetime spectroscopy probe to quantitatively and noninvasively assess tissue constructs that were implanted in a murine model. We designed the system to be suitable for intravital measurements: portability, localization with precise maneuverability, and rapid data acquisition. Our model tissue constructs were manufactured from primary human cells to simulate patient variability and were stressed to create a range of health states. Secreted amounts of three cytokines that relate to cellular viability were measured in vitro to assess pre-implantation construct health. In vivo optical sensing assessed tissue integration of constructs at one-week and three-weeks post-implantation. At one-week post-implantation, optical parameters correlated with in vitro pre-implantation secretion levels of all three cytokines (p clinical optical diagnostic tools based on label-free fluorescence lifetime sensing of endogenous tissue fluorophores could noninvasively monitor post-implantation integration of engineered tissues.

Validity of a Questionnaire to Assess the Physical Activity Level in Coronary Artery Disease Patients

Science.gov (United States)

Guiraud, Thibaut; Granger, Richard; Bousquet, Marc; Gremeaux, Vincent

2012-01-01

The aim of the study is to compare, in coronary artery disease patients, physical activity (PA) assessed with the Dijon Physical Activity Questionnaire (DPAQ) and the true PA objectively measured using an accelerometer. Seventy patients wore an accelerometer (MyWellness Key actimeter) throughout 1 week after a cardiac rehabilitation program that…

Bacteria of leg atheromatous arteries responsible for inflammation.

Science.gov (United States)

Olszewski, Waldemar Lech; Rutkowska, Joanna; Moscicka-Wesolowska, Maria; Swoboda-Kopec, Ewa; Stelmach, Ewa; Zaleska, Marzanna; Zagozda, Malgorzata

2016-09-01

Ischaemia of the lower limbs is frequently followed by inflammation and, in advanced cases, necrosis of peripheral tissues. Whether this is caused by arterial hypoperfusion only or by the presence of bacteria in the arterial walI as well remains unclear. The aim of the study was to prove the presence and source of bacteria in arterial specimens and evaluate their chemotactic properties resulting in the formation of periarterial cellular infiltrates. Bacterial culture and testing for 16sRNA were performed in fragments of popliteal artery harvested from amputated limbs. Carotid artery plaques served as controls. Fragments of arteries were transplanted into scid mice to evaluate their chemotactic activity for macrophages. a) higher prevalence of isolates and 16sRNA in atherosclerotic popliteal than carotid arteries, b) high density of plaque and periarterial infiltrates and mRNA level for pro-inflammatory cytokines in popliteal arteries, c) prevalent microbes were Staphylococcus aureus, S. epidermidis and Enterococci, d) foot skin and arterial bacterial phenotypes and DNA revealed evident similarities, and e) more intensive mouse macrophage accumulation in popliteal than carotid implants into scid mice. The presence of bacteria in the lower limb arterial wall was documented. They may predispose to inflammation secondary to ischaemic changes.

Telerobotic system concept for real-time soft-tissue imaging during radiotherapy beam delivery.

Science.gov (United States)

Schlosser, Jeffrey; Salisbury, Kenneth; Hristov, Dimitre

2010-12-01

The curative potential of external beam radiation therapy is critically dependent on having the ability to accurately aim radiation beams at intended targets while avoiding surrounding healthy tissues. However, existing technologies are incapable of real-time, volumetric, soft-tissue imaging during radiation beam delivery, when accurate target tracking is most critical. The authors address this challenge in the development and evaluation of a novel, minimally interfering, telerobotic ultrasound (U.S.) imaging system that can be integrated with existing medical linear accelerators (LINACs) for therapy guidance. A customized human-safe robotic manipulator was designed and built to control the pressure and pitch of an abdominal U.S. transducer while avoiding LINAC gantry collisions. A haptic device was integrated to remotely control the robotic manipulator motion and U.S. image acquisition outside the LINAC room. The ability of the system to continuously maintain high quality prostate images was evaluated in volunteers over extended time periods. Treatment feasibility was assessed by comparing a clinically deployed prostate treatment plan to an alternative plan in which beam directions were restricted to sectors that did not interfere with the transabdominal U.S. transducer. To demonstrate imaging capability concurrent with delivery, robot performance and U.S. target tracking in a phantom were tested with a 15 MV radiation beam active. Remote image acquisition and maintenance of image quality with the haptic interface was successfully demonstrated over 10 min periods in representative treatment setups of volunteers. Furthermore, the robot's ability to maintain a constant probe force and desired pitch angle was unaffected by the LINAC beam. For a representative prostate patient, the dose-volume histogram (DVH) for a plan with restricted sectors remained virtually identical to the DVH of a clinically deployed plan. With reduced margins, as would be enabled by real-time

Telerobotic system concept for real-time soft-tissue imaging during radiotherapy beam delivery

International Nuclear Information System (INIS)

Schlosser, Jeffrey; Salisbury, Kenneth; Hristov, Dimitre

2010-01-01

Purpose: The curative potential of external beam radiation therapy is critically dependent on having the ability to accurately aim radiation beams at intended targets while avoiding surrounding healthy tissues. However, existing technologies are incapable of real-time, volumetric, soft-tissue imaging during radiation beam delivery, when accurate target tracking is most critical. The authors address this challenge in the development and evaluation of a novel, minimally interfering, telerobotic ultrasound (U.S.) imaging system that can be integrated with existing medical linear accelerators (LINACs) for therapy guidance. Methods: A customized human-safe robotic manipulator was designed and built to control the pressure and pitch of an abdominal U.S. transducer while avoiding LINAC gantry collisions. A haptic device was integrated to remotely control the robotic manipulator motion and U.S. image acquisition outside the LINAC room. The ability of the system to continuously maintain high quality prostate images was evaluated in volunteers over extended time periods. Treatment feasibility was assessed by comparing a clinically deployed prostate treatment plan to an alternative plan in which beam directions were restricted to sectors that did not interfere with the transabdominal U.S. transducer. To demonstrate imaging capability concurrent with delivery, robot performance and U.S. target tracking in a phantom were tested with a 15 MV radiation beam active. Results: Remote image acquisition and maintenance of image quality with the haptic interface was successfully demonstrated over 10 min periods in representative treatment setups of volunteers. Furthermore, the robot's ability to maintain a constant probe force and desired pitch angle was unaffected by the LINAC beam. For a representative prostate patient, the dose-volume histogram (DVH) for a plan with restricted sectors remained virtually identical to the DVH of a clinically deployed plan. With reduced margins, as

Real-time integration of 3-D multimodality data in interventional neuroangiography

NARCIS (Netherlands)

Ruijters, D.; Babic, D.; Homan, R.; Mielekamp, P.; Haar Romenij, ter B.M.; Suetens, P.

2009-01-01

We describe a novel approach to using soft-tissue data sets, such as computer tomography on magnetic resonance, in the minimally invasive image guidance of intra-arterial and intravenous endovascular devices in neuroangiography interventions. Minimally invasive x-ray angiography procedures rely on

Integrated approaches to spatiotemporally directing angiogenesis in host and engineered tissues.

Science.gov (United States)

Kant, Rajeev J; Coulombe, Kareen L K

2018-03-15

The field of tissue engineering has turned towards biomimicry to solve the problem of tissue oxygenation and nutrient/waste exchange through the development of vasculature. Induction of angiogenesis and subsequent development of a vascular bed in engineered tissues is actively being pursued through combinations of physical and chemical cues, notably through the presentation of topographies and growth factors. Presenting angiogenic signals in a spatiotemporal fashion is beginning to generate improved vascular networks, which will allow for the creation of large and dense engineered tissues. This review provides a brief background on the cells, mechanisms, and molecules driving vascular development (including angiogenesis), followed by how biomaterials and growth factors can be used to direct vessel formation and maturation. Techniques to accomplish spatiotemporal control of vascularization include incorporation or encapsulation of growth factors, topographical engineering, and 3D bioprinting. The vascularization of engineered tissues and their application in angiogenic therapy in vivo is reviewed herein with an emphasis on the most densely vascularized tissue of the human body - the heart. Vascularization is vital to wound healing and tissue regeneration, and development of hierarchical networks enables efficient nutrient transfer. In tissue engineering, vascularization is necessary to support physiologically dense engineered tissues, and thus the field seeks to induce vascular formation using biomaterials and chemical signals to provide appropriate, pro-angiogenic signals for cells. This review critically examines the materials and techniques used to generate scaffolds with spatiotemporal cues to direct vascularization in engineered and host tissues in vitro and in vivo. Assessment of the field's progress is intended to inspire vascular applications across all forms of tissue engineering with a specific focus on highlighting the nuances of cardiac tissue

Label-free imaging of arterial cells and extracellular matrix using a multimodal CARS microscope

Science.gov (United States)

Wang, Han-Wei; Le, Thuc T.; Cheng, Ji-Xin

2008-04-01

A multimodal nonlinear optical imaging system that integrates coherent anti-Stokes Raman scattering (CARS), sum-frequency generation (SFG), and two-photon excitation fluorescence (TPEF) on the same platform was developed and applied to visualize single cells and extracellular matrix in fresh carotid arteries. CARS signals arising from CH 2-rich membranes allowed visualization of endothelial cells and smooth muscle cells of the arterial wall. Additionally, CARS microscopy allowed vibrational imaging of elastin and collagen fibrils which are also rich in CH 2 bonds. The extracellular matrix organization was further confirmed by TPEF signals arising from elastin's autofluorescence and SFG signals arising from collagen fibrils' non-centrosymmetric structure. Label-free imaging of significant components of arterial tissues suggests the potential application of multimodal nonlinear optical microscopy to monitor onset and progression of arterial diseases.

Preliminary analysis of proteome alterations in non-aneurysmal, internal mammary artery tissue from patients with abdominal aortic aneurysms

DEFF Research Database (Denmark)

Kidholm, Christina Lund; Beck, Hans Christian; Madsen, Julie Bukh

2018-01-01

with AAA and 33 sex- and age-matched controls without AAA. Samples were selected from a biobank of leftover internal mammary arterial tissue gathered at coronary by-pass operations. Results We identified and quantitated 877 proteins, of which 44 were differentially expressed between the two groups (nominal...

The effects of frozen tissue storage conditions on the integrity of RNA and protein.

Science.gov (United States)

Auer, H; Mobley, J A; Ayers, L W; Bowen, J; Chuaqui, R F; Johnson, L A; Livolsi, V A; Lubensky, I A; McGarvey, D; Monovich, L C; Moskaluk, C A; Rumpel, C A; Sexton, K C; Washington, M K; Wiles, K R; Grizzle, W E; Ramirez, N C

2014-10-01

Unfixed tissue specimens most frequently are stored for long term research uses at either -80° C or in vapor phase liquid nitrogen (VPLN). There is little information concerning the effects such long term storage on tissue RNA or protein available for extraction. Aliquots of 49 specimens were stored for 5-12 years at -80° C or in VPLN. Twelve additional paired specimens were stored for 1 year under identical conditions. RNA was isolated from all tissues and assessed for RNA yield, total RNA integrity and mRNA integrity. Protein stability was analyzed by surface-enhanced or matrix-assisted laser desorption ionization time of flight mass spectrometry (SELDI-TOF-MS, MALDI-TOF-MS) and nano-liquid chromatography electrospray ionization tandem mass spectrometry (nLC-ESI-MS/MS). RNA yield and total RNA integrity showed significantly better results for -80° C storage compared to VPLN storage; the transcripts that were preferentially degraded during VPLN storage were these involved in antigen presentation and processing. No consistent differences were found in the SELDI-TOF-MS, MALDI-TOF-MS or nLC-ESI-MS/MS analyses of specimens stored for more than 8 years at -80° C compared to those stored in VPLN. Long term storage of human research tissues at -80° C provides at least the same quality of RNA and protein as storage in VPLN.

Beneficial Effects of Renal Denervation on Pulmonary Vascular Remodeling in Experimental Pulmonary Artery Hypertension.

Science.gov (United States)

Qingyan, Zhao; Xuejun, Jiang; Yanhong, Tang; Zixuan, Dai; Xiaozhan, Wang; Xule, Wang; Zongwen, Guo; Wei, Hu; Shengbo, Yu; Congxin, Huang

2015-07-01

Activation of both the sympathetic nervous system and the renin-angiotensin-aldosterone system is closely associated with pulmonary arterial hypertension. We hypothesized that renal denervation decreases renin-angiotensin-aldosterone activity and inhibits the progression of pulmonary arterial hypertension. Twenty-two beagles were randomized into 3 groups. The dogs' pulmonary dynamics were measured before and 8 weeks after injection of 0.1mL/kg dimethylformamide (control dogs) or 2mg/kg dehydromonocrotaline (pulmonary arterial hypertension and pulmonary arterial hypertension + renal denervation dogs). Eight weeks after injection, neurohormone levels and pulmonary tissue morphology were measured. Levels of plasma angiotensin II and endothelin-1 were significantly increased after 8 weeks in the pulmonary arterial hypertension dogs and were higher in the lung tissues of these dogs than in those of the control and renal denervation dogs (mean [standard deviation] angiotensin II: 65 [9.8] vs 38 [6.7], 46 [8.1]; endothelin-1: 96 [10.3] vs 54 [6.2], 67 [9.4]; P < .01). Dehydromonocrotaline increased the mean pulmonary arterial pressure (16 [3.4] mmHg vs 33 [7.3] mmHg; P < .01), and renal denervation prevented this increase. Pulmonary smooth muscle cell proliferation was higher in the pulmonary arterial hypertension dogs than in the control and pulmonary arterial hypertension + renal denervation dogs. Renal denervation attenuates pulmonary vascular remodeling and decreases pulmonary arterial pressure in experimental pulmonary arterial hypertension. The effect of renal denervation may contribute to decreased neurohormone levels. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Role of high-resolution image integration to visualize left phrenic nerve and coronary arteries during epicardial ventricular tachycardia ablation.

Science.gov (United States)

Yamashita, Seigo; Sacher, Frédéric; Mahida, Saagar; Berte, Benjamin; Lim, Han S; Komatsu, Yuki; Amraoui, Sana; Denis, Arnaud; Derval, Nicolas; Laurent, François; Montaudon, Michel; Hocini, Mélèze; Haïssaguerre, Michel; Jaïs, Pierre; Cochet, Hubert

2015-04-01

Epicardial ventricular tachycardia (VT) ablation is associated with risks of coronary artery (CA) and phrenic nerve (PN) injury. We investigated the role of multidetector computed tomography in visualizing CA and PN during VT ablation. Ninety-five consecutive patients (86 men; age, 57 ± 15) with VT underwent cardiac multidetector computed tomography. The PN detection rate and anatomic variability were analyzed. In 49 patients undergoing epicardial mapping, real-time multidetector computed tomographic integration was used to display CAs/PN locations in 3-dimensional mapping systems. Elimination of local abnormal ventricular activities (LAVAs) was used as ablation end point. The distribution of CAs/PN with respect to LAVA was analyzed and compared between VT etiologies. Multidetector computed tomography detected PN in 81 patients (85%). Epicardial LAVAs were observed in 44 of 49 patients (15 ischemic cardiomyopathy, 15 nonischemic cardiomyopathy, and 14 arrhythmogenic right ventricular cardiomyopathy) with a mean of 35 ± 37 LAVA points/patient. LAVAs were located within 1 cm from CAs and PN in 35 (80%) and 18 (37%) patients, respectively. The prevalence of LAVA adjacent to CAs was higher in nonischemic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy than in ischemic cardiomyopathy (100% versus 86% versus 53%; P < 0.01). The prevalence of LAVAs adjacent to PN was higher in nonischemic cardiomyopathy than in ischemic cardiomyopathy (93% versus 27%; P < 0.001). Epicardial ablation was performed in 37 patients (76%). Epicardial LAVAs could not be eliminated because of the proximity to CAs or PN in 8 patients (18%). The epicardial electrophysiological VT substrate is often close to CAs and PN in patients with nonischemic cardiomyopathy. High-resolution image integration is potentially useful to minimize risks of PN and CA injury during epicardial VT ablation. © 2015 American Heart Association, Inc.

Hyperthyroidism enhances 5-HT-induced contraction of the rat pulmonary artery: role of calcium-activated chloride channel activation.

Science.gov (United States)

Oriowo, Mabayoje A; Oommen, Elsie; Khan, Islam

2011-11-01

Experimentally-induced hyperthyroidism in rodents is associated with signs and symptoms of pulmonary hypertension. The main objective of the present study was to investigate the effect of thyroxine-induced pulmonary hypertension on the contractile response of the pulmonary artery to 5-HT and the possible underlying signaling pathway. 5-HT concentration-dependently contracted artery segments from control and thyroxine-treated rats with pD(2) values of 5.04 ± 0.19 and 5.34 ± 0.14, respectively. The maximum response was significantly greater in artery segments from thyroxine-treated rats. Neither BW 723C86 (5-HT(2B)-receptor agonist) nor CP 93129 (5-HT(1B)-receptor agonist) contracted ring segments of the pulmonary artery from control and thyroxine-treated rats at concentrations up to 10(-4)M. There was no significant difference in the level of expression of 5-HT(2A)-receptor protein between the two groups. Ketanserin (3 × 10(-8)M) produced a rightward shift of the concentration-response curve to 5-HT in both groups with equal potency (-logK(B) values were 8.1 ± 0.2 and 7.9 ± 0.1 in control and thyroxine-treated rats, respectively). Nifedipine (10(-6)M) inhibited 5-HT-induced contractions in artery segments from control and thyroxine-treated rats and was more effective against 5-HT-induced contraction in artery segments for thyroxine-treated rats. The calcium-activated chloride channel blocker, niflumic acid (10(-4)M) also inhibited 5-HT-induced contractions in artery segments from control and thyroxine-treated rats and was more effective against 5-HT-induced contraction in artery segments for thyroxine-treated rats. It was concluded that hyperthyroidism enhanced 5-HT-induced contractions of the rat pulmonary artery by a mechanism involving increased activity of calcium-activated chloride channels. Copyright © 2011 Elsevier B.V. All rights reserved.

Placental vascular responses are dependent on surrounding tissue

DEFF Research Database (Denmark)

Brøgger, Torbjørn Halle

-depth understanding of the mechanism regulating blood flow and perfusion is necessary if we are to come up with new ideas for intervention and treatment. Method: From fresh born placentas stem villi arteries were carefully dissected. The artery branches were divided. The surrounding tissue was removed from one end...... and was left untouched in the other end. Then using wire myography they were investigated in terms of contractility and sensitivity to physiological relevant human-like agonists. Results: Sensitivity to PGF2α, Tx-analog, 5-HT and endothelin-1 was significantly lower in arteries with intact surrounding tissue...... compared to arteries stripped of the tissue. The maximal force development was also significantly lower in arteries with surrounding tissue, when they were depolarized high extracellular [K+] or stimulated with PGF2α or endotheline-1. Conclusion: The perivascular tissue significantly alters stem villi...

An integrated finite-element approach to mechanics, transport and biosynthesis in tissue engineering

NARCIS (Netherlands)

Sengers, B.G.; Oomens, C.W.J.; Baaijens, F.P.T.

2004-01-01

A finite-element approach was formulated, aimed at enabling an integrated study of mechanical and biochemical factors that control the functional development of tissue engineered constructs. A nonlinear biphasic displacement-velocity-pressure description was combined with adjective and diffusive

ITE inhibits growth of human pulmonary artery endothelial cells.

Science.gov (United States)

Pang, Ling-Pin; Li, Yan; Zou, Qing-Yun; Zhou, Chi; Lei, Wei; Zheng, Jing; Huang, Shi-An

2017-10-01

Pulmonary arterial hypertension (PAH), a deadly disorder is associated with excessive growth of human pulmonary artery endothelial (HPAECs) and smooth muscle (HPASMCs) cells. Current therapies primarily aim at promoting vasodilation, which only ameliorates clinical symptoms without a cure. 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) is an endogenous aryl hydrocarbon receptor (AhR) ligand, and mediates many cellular function including cell growth. However, the roles of ITE in human lung endothelial cells remain elusive. Herein, we tested a hypothesis that ITE inhibits growth of human pulmonary artery endothelial cells via AhR. Immunohistochemistry was performed to localize AhR expression in human lung tissues. The crystal violet method and MTT assay were used to determine ITE's effects on growth of HPAECs. The AhR activation in HPAECs was confirmed using Western blotting and RT-qPCR. The role of AhR in ITE-affected proliferation of HPAECs was assessed using siRNA knockdown method followed by the crystal violet method. Immunohistochemistry revealed that AhR was present in human lung tissues, primarily in endothelial and smooth muscle cells of pulmonary veins and arteries, as well as in bronchial and alveolar sac epithelia. We also found that ITE dose- and time-dependently inhibited proliferation of HPAECs with a maximum inhibition of 83% at 20 µM after 6 days of treatment. ITE rapidly decreased AhR protein levels, while it increased mRNA levels of cytochrome P450 (CYP), family 1, member A1 (CYP1A1) and B1 (CYP1B1), indicating activation of the AhR/CYP1A1 and AhR/CYP1B1 pathways in HPAECs. The AhR siRNA significantly suppressed AhR protein expression, whereas it did not significantly alter ITE-inhibited growth of HPAECs. ITE suppresses growth of HPAECs independent of AhR, suggesting that ITE may play an important role in preventing excessive growth of lung endothelial cells.

Tissue-Muscle Perfusion Scintigraphy of the Lower Limbs in a Patient with Type 2 Diabetes Mellitus and Peripheral Arterial Disease

Directory of Open Access Journals (Sweden)

Irfan Ahmet

2016-02-01

Full Text Available The estimation of tissue perfusion as a hemodynamic consequence of peripheral arterial disease (PAD in diabetic patients is of great importance in the management of these patients.We present a noninvasive, functional method of 99mTc-MIBI (methoxy-isobutyl-isonitrile tissue-muscle perfusion scintigraphy (TMPS of the lower limbs, which assesses tissue perfusion in basal conditions (“rest” study and exercise conditions (“stress” study. Emphasis is given on perfusion reserve (PR as an important indicator of preservation of microcirculation and its local autoregulatory mechanisms in PAD. We present a case of a 71-year-old male diabetic patient with skin ulcers of the right foot and an ankle-brachial index >1.2 (0.9-1.1. Dynamic phase TMPS of the lower limbs showed decreased and late arterial vascularization of the right calf (RC with lower percentage of radioactivity in the 1st minute: RC 66%, left calf (LC 84%. PR was borderline with a value of 57% for LC and decreased for RC (42%. Functional assessment of hemodynamic consequences of PAD is important in evaluating both advanced and early PAD, especially the asymptomatic form. The method used to determine the TMPS of the lower limbs, can differentiate subtle changes in microcirculation and tissue perfusion

Transcatheter Arterial Embolization of Arterial Esophageal Bleeding with the Use of N-Butyl Cyanoacrylate

Energy Technology Data Exchange (ETDEWEB)

Park, Ji Hoon; Kim, Hyo Cheol; Chung, Jin Wook; Jae, Hwan Jun; Park, Jae Hyung [Seoul National University Hospita, Seoul (Korea, Republic of)

2009-08-15

To evaluate the clinical efficacy and safety of a transcatheter arterial embolization (TAE) with N-butyl cyanoacrylate (NBCA) for the treatment of arterial esophageal bleeding. Between August 2000 and April 2008, five patients diagnosed with arterial esophageal bleeding by conventional angiography, CT angiography or endoscopy, underwent a TAE with NBCA. We mixed NBCA with iodized oil at ratios of 1:1 to 1:4 to supply radiopacity and achieve a proper polymerization time. After embolization, we evaluated the angiographic and clinical success, recurrent bleeding, and procedure-related complications. The bleeding esophageal artery directly originated from the aorta in four patients and from the left inferior phrenic artery in one patient. Although four patients had an underlying coagulopathy at the time of the TAE, angiographic and clinical success was achieved in all five patients. In addition, no procedurerelated complications such as esophageal infarction were observed during this study. NBCA can be an effective and feasible embolic agent in patients with active arterial esophageal bleeding, even with pre-existing coagulopathy.

Transcatheter Arterial Embolization of Arterial Esophageal Bleeding with the Use of N-Butyl Cyanoacrylate

International Nuclear Information System (INIS)

Park, Ji Hoon; Kim, Hyo Cheol; Chung, Jin Wook; Jae, Hwan Jun; Park, Jae Hyung

2009-01-01

To evaluate the clinical efficacy and safety of a transcatheter arterial embolization (TAE) with N-butyl cyanoacrylate (NBCA) for the treatment of arterial esophageal bleeding. Between August 2000 and April 2008, five patients diagnosed with arterial esophageal bleeding by conventional angiography, CT angiography or endoscopy, underwent a TAE with NBCA. We mixed NBCA with iodized oil at ratios of 1:1 to 1:4 to supply radiopacity and achieve a proper polymerization time. After embolization, we evaluated the angiographic and clinical success, recurrent bleeding, and procedure-related complications. The bleeding esophageal artery directly originated from the aorta in four patients and from the left inferior phrenic artery in one patient. Although four patients had an underlying coagulopathy at the time of the TAE, angiographic and clinical success was achieved in all five patients. In addition, no procedurerelated complications such as esophageal infarction were observed during this study. NBCA can be an effective and feasible embolic agent in patients with active arterial esophageal bleeding, even with pre-existing coagulopathy

TISSUES 2.0: an integrative web resource on mammalian tissue expression.

Science.gov (United States)

Palasca, Oana; Santos, Alberto; Stolte, Christian; Gorodkin, Jan; Jensen, Lars Juhl

2018-01-01

Physiological and molecular similarities between organisms make it possible to translate findings from simpler experimental systems—model organisms—into more complex ones, such as human. This translation facilitates the understanding of biological processes under normal or disease conditions. Researchers aiming to identify the similarities and differences between organisms at the molecular level need resources collecting multi-organism tissue expression data. We have developed a database of gene–tissue associations in human, mouse, rat and pig by integrating multiple sources of evidence: transcriptomics covering all four species and proteomics (human only), manually curated and mined from the scientific literature. Through a scoring scheme, these associations are made comparable across all sources of evidence and across organisms. Furthermore, the scoring produces a confidence score assigned to each of the associations. The TISSUES database (version 2.0) is publicly accessible through a user-friendly web interface and as part of the STRING app for Cytoscape. In addition, we analyzed the agreement between datasets, across and within organisms, and identified that the agreement is mainly affected by the quality of the datasets rather than by the technologies used or organisms compared. http://tissues.jensenlab.org/

Using Online Lectures to Make Time for Active Learning

Science.gov (United States)

Prunuske, Amy J.; Batzli, Janet; Howell, Evelyn; Miller, Sarah

2012-01-01

To make time in class for group activities devoted to critical thinking, we integrated a series of short online lectures into the homework assignments of a large, introductory biology course at a research university. The majority of students viewed the online lectures before coming to class and reported that the online lectures helped them to complete the in-class activity and did not increase the amount of time they devoted to the course. In addition, students who viewed the online lecture performed better on clicker questions designed to test lower-order cognitive skills. The in-class activities then gave the students practice analyzing the information in groups and provided the instructor with feedback about the students’ understanding of the material. On the basis of the results of this study, we support creating hybrid course models that allow students to learn the fundamental information outside of class time, thereby creating time during the class period to be dedicated toward the conceptual understanding of the material. PMID:22714412

Multifunctional Hydrogel with Good Structure Integrity, Self-Healing, and Tissue-Adhesive Property Formed by Combining Diels-Alder Click Reaction and Acylhydrazone Bond.

Science.gov (United States)

Yu, Feng; Cao, Xiaodong; Du, Jie; Wang, Gang; Chen, Xiaofeng

2015-11-04

Hydrogel, as a good cartilage tissue-engineered scaffold, not only has to possess robust mechanical property but also has to have an intrinsic self-healing property to integrate itself or the surrounding host cartilage. In this work a double cross-linked network (DN) was designed and prepared by combining Diels-Alder click reaction and acylhydrazone bond. The DA reaction maintained the hydrogel's structural integrity and mechanical strength in physiological environment, while the dynamic covalent acylhydrazone bond resulted in hydrogel's self-healing property and controlled the on-off switch of network cross-link density. At the same time, the aldehyde groups contained in hydrogel further promote good integration of the hydrogel to surrounding tissue based on aldehyde-amine Schiff-base reaction. This kind of hydrogel has good structural integrity, autonomous self-healing, and tissue-adhesive property and simultaneously will have a good application in tissue engineering and tissue repair field.

Modeling, implementation, and validation of arterial travel time reliability.

Science.gov (United States)

2013-11-01

Previous research funded by Florida Department of Transportation (FDOT) developed a method for estimating : travel time reliability for arterials. This method was not initially implemented or validated using field data. This : project evaluated and r...

Real-time optoacoustic monitoring of temperature in tissues

International Nuclear Information System (INIS)

Larina, Irina V; Larin, Kirill V; Esenaliev, Rinat O

2005-01-01

To improve the safety and efficacy of thermal therapy, it is necessary to map tissue temperature in real time with submillimetre spatial resolution. Accurate temperature maps may provide the necessary control of the boundaries of the heated regions and minimize thermal damage to surrounding normal tissues. Current imaging modalities fail to monitor tissue temperature in real time with high resolution and accuracy. We investigated a non-invasive optoacoustic method for accurate, real-time monitoring of tissue temperature during thermotherapy. In this study, we induced temperature gradients in tissue and tissue-like samples and monitored the temperature distribution using the optoacoustic technique. The fundamental harmonic of a Q-switched Nd : YAG laser (λ = 1064 nm) was used for optoacoustic wave generation and probing of tissue temperature. The tissue temperature was also monitored with a multi-sensor temperature probe inserted in the samples. Good agreement between optoacoustically measured and actual tissue temperatures was obtained. The accuracy of temperature monitoring was better than 1 0 C, while the spatial resolution was about 1 mm. These data suggest that the optoacoustic technique has the potential to be used for non-invasive, real-time temperature monitoring during thermotherapy

Not only the sugar, early infarct sign, hyperDense middle cerebral artery, age, neurologic deficit score but also atrial fibrillation is predictive for symptomatic intracranial hemorrhage after intravenous recombinant tissue plasminogen activator

Directory of Open Access Journals (Sweden)

Sombat Muengtaweepongsa

2017-01-01

Full Text Available Background: Symptomatic intracranial hemorrhage (sICH is the most unwanted adverse event in patients with acute ischemic stroke who received intravenous recombinant tissue plasminogen activator (i.v. rt-PA. Many tool scores are available to predict the probability of sICH. Among those scores, the Sugar, Early infarct sign, hyperDense middle cerebral artery, Age, Neurologic deficit (SEDAN gives the highest area under the curve-receiver operating characteristic value. Objective: We aimed to examine any factors other than the SEDAN score to predict the probability of sICH. Methods: Patients with acute ischemic stroke treated with i.v. rt-PA within 4.5 h time window from January 2010 to July 2012 were evaluated. Compiling demographic data, risk factors, and comorbidity (hypertension, diabetes mellitus, dyslipidemia, atrial fibrillation (AF, ischemic heart disease, valvular heart disease, previous stroke, gout, smoking cigarette, drinking alcoholic beverage, family history of stroke, and family history of ischemic heart disease, computed tomography scan of patients prior to treatment with rt-PA, and assessing the National Institutes of Health Stroke Scale (NIHSS score for the purpose of calculating SEDAN score were analyzed. Results: Of 314 patients treated with i.v. rt-PA, there were 46 ICH cases (14.6% with 14 sICH (4.4% and 32 asymptomatic intracranial hemorrhage cases (10.2%. The rate of sICH occurrence was increased in accordance with the increase in the SEDAN score and AF. Age over 75 years, early infarction, hyperdense cerebral artery, baseline blood sugar more than 12 mmol/l, NIHSS as 10 or more, and AF were the risk factors to develop sICH after treated with rt-PA at 1.535, 2.501, 1.093, 1.276, 1.253, and 2.492 times, respectively. Conclusions: Rather than the SEDAN score, AF should be a predictor of sICH in patients with acute ischemic stroke after i.v. rt-PA treatment in Thai population.

Ruminant Metabolic Systems Biology: Reconstruction and Integration of Transcriptome Dynamics Underlying Functional Responses of Tissues to Nutrition and Physiological Statea

Science.gov (United States)

Bionaz, Massimo; Loor, Juan J.

2012-01-01

High-throughput ‘omics’ data analysis via bioinformatics is one key component of the systems biology approach. The systems approach is particularly well-suited for the study of the interactions between nutrition and physiological state with tissue metabolism and functions during key life stages of organisms such as the transition from pregnancy to lactation in mammals, ie, the peripartal period. In modern dairy cows with an unprecedented genetic potential for milk synthesis, the nature of the physiologic and metabolic adaptations during the peripartal period is multifaceted and involves key tissues such as liver, adipose, and mammary. In order to understand such adaptation, we have reviewed several works performed in our and other labs. In addition, we have used a novel bioinformatics approach, Dynamic Impact Approach (DIA), in combination with partly previously published data to help interpret longitudinal biological adaptations of bovine liver, adipose, and mammary tissue to lactation using transcriptomics datasets. Use of DIA with transcriptomic data from those tissues during normal physiological adaptations and in animals fed different levels of energy prepartum allowed visualization and integration of most-impacted metabolic pathways around the time of parturition. The DIA is a suitable tool for applying the integrative systems biology approach. The ultimate goal is to visualize the complexity of the systems at study and uncover key molecular players involved in the tissue’s adaptations to physiological state or nutrition. PMID:22807626

Phantom with Pulsatile Arteries to Investigate the Influence of Blood Vessel Depth on Pulse Oximeter Signal Strength

OpenAIRE

Stuban, Norbert; Niwayama, Masatsugu; Santha, Hunor

2012-01-01

This paper describes a three-layer head phantom with artificial pulsating arteries at five different depths (1.2 mm, 3.7 mm, 6.8 mm, 9.6 mm and 11.8 mm). The structure enables formation of spatially and temporally varying tissue properties similar to those of living tissues. In our experiment, pressure pulses were generated in the arteries by an electronically controlled pump. The physical and optical parameters of the layers and the liquid in the artificial arteries were similar to those of ...

Laser microtexturing of implant surfaces for enhanced tissue integration

Energy Technology Data Exchange (ETDEWEB)

Ricci, J.L. [Univ. of Medicine and Dentistry of New Jersey, Newark, NJ (United States). Dept. of Orthodontics; Alexander, H. [Orthogen Corp., Springfield, NJ (United States)

2001-07-01

The success or failure of bone and soft tissue-fixed medical devices, such as dental and orthopaedic implants, depends on a complex combination of biological and mechanical factors. These factors are intimately associated with the interface between the implant surface and the surrounding tissue, and are largely determined by the composition, surface chemistry, and surface microgeometry of the implant. The relative contributions of these factors are difficult to assess. This study addresses the contribution of surface microtexture, on a controlled level, to tissue integration. (orig.)

Biomarkers of coagulation, fibrinolysis, endothelial function, and inflammation in arterialized venous blood

DEFF Research Database (Denmark)

Gram, Anne Sofie; Skov, Jane; Ploug, Thorkil

2014-01-01

Effects of venous blood arterialization on cardiovascular risk markers are still unknown. We evaluated biomarkers of inflammation, coagulation, fibrinolysis, and endothelial function in arterialized compared with regular venous blood. Cubital venipunctures were obtained from 10 healthy volunteers....... Arterialization was generated by 10 min heating of the contralateral hand. Concentrations of albumin, C-reactive protein (CRP), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor type 1 (PAI-1), and von Willebrand factor (vWF) were measured by validated assays. Concentrations of albumin......, CRP, and vWF were significantly lower in arterialized than in venous blood (albumin: 43.8 g/l and 44.8 g/l, P = 0.02). Differences in CRP and vWF became insignificant after adjusting for albumin. The endogenous thrombin potential (ETP) was significantly higher in arterialized than in venous blood...

Phantom with pulsatile arteries to investigate the influence of blood vessel depth on pulse oximeter signal strength.

Science.gov (United States)

Stuban, Norbert; Niwayama, Masatsugu; Santha, Hunor

2012-01-01

This paper describes a three-layer head phantom with artificial pulsating arteries at five different depths (1.2 mm, 3.7 mm, 6.8 mm, 9.6 mm and 11.8 mm). The structure enables formation of spatially and temporally varying tissue properties similar to those of living tissues. In our experiment, pressure pulses were generated in the arteries by an electronically controlled pump. The physical and optical parameters of the layers and the liquid in the artificial arteries were similar to those of real tissues and blood. The amplitude of the pulsating component of the light returning from the phantom tissues was measured at each artery depth mentioned above. The build-up of the in-house-developed pulse oximeter used for performing the measurements and the physical layout of the measuring head are described. The radiant flux generated by the LED on the measuring head was measured to be 1.8 mW at 910 nm. The backscattered radiant flux was measured, and found to be 0.46 nW (0.26 ppm), 0.55 nW (0.31 ppm), and 0.18 nW (0.10 ppm) for the 1.2 mm, 3.7 mm and 6.8 mm arteries, respectively. In the case of the 9.6 mm and 11.8 mm arteries, useful measurement data were not obtained owing to weak signals. We simulated the phantom with the arteries at the above-mentioned five depths and at two additional ones (2.5 mm and 5.3 mm in depth) using the Monte Carlo method. The measurement results were verified by the simulation results. We concluded that in case of 11 mm source-detector separation the arteries at a depth of about 2.5 mm generate the strongest pulse oximeter signal level in a tissue system comprising three layers of thicknesses: 1.5 mm (skin), 5.0 mm (skull), and >50 mm (brain).

Phantom with Pulsatile Arteries to Investigate the Influence of Blood Vessel Depth on Pulse Oximeter Signal Strength

Directory of Open Access Journals (Sweden)

Hunor Santha

2012-01-01

Full Text Available This paper describes a three-layer head phantom with artificial pulsating arteries at five different depths (1.2 mm, 3.7 mm, 6.8 mm, 9.6 mm and 11.8 mm. The structure enables formation of spatially and temporally varying tissue properties similar to those of living tissues. In our experiment, pressure pulses were generated in the arteries by an electronically controlled pump. The physical and optical parameters of the layers and the liquid in the artificial arteries were similar to those of real tissues and blood. The amplitude of the pulsating component of the light returning from the phantom tissues was measured at each artery depth mentioned above. The build-up of the in-house-developed pulse oximeter used for performing the measurements and the physical layout of the measuring head are described. The radiant flux generated by the LED on the measuring head was measured to be 1.8 mW at 910 nm. The backscattered radiant flux was measured, and found to be 0.46 nW (0.26 ppm, 0.55 nW (0.31 ppm, and 0.18 nW (0.10 ppm for the 1.2 mm, 3.7 mm and 6.8 mm arteries, respectively. In the case of the 9.6 mm and 11.8 mm arteries, useful measurement data were not obtained owing to weak signals. We simulated the phantom with the arteries at the above-mentioned five depths and at two additional ones (2.5 mm and 5.3 mm in depth using the Monte Carlo method. The measurement results were verified by the simulation results. We concluded that in case of 11 mm source-detector separation the arteries at a depth of about 2.5 mm generate the strongest pulse oximeter signal level in a tissue system comprising three layers of thicknesses: 1.5 mm (skin, 5.0 mm (skull, and > 50 mm (brain.

Late Posthemorrhagic Structural and Functional Changes in Pulmonary Circulation Arteries

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S. A. Andreyeva

2008-01-01

Full Text Available Objective: to reveal the major regularities and mechanisms of morphological changes in the rat pulmonary circulation arteries in the late posthemorrhagic period and to compare them with age-related features of the vessels. Materials and methods: experiments to generate graduated hemorrhagic hypotension with the blood pressure being maintained at 40 mm Hg were carried out on young (5—6-month albino male Wistar rats. Throughout hypotension and 60 days after blood loss, the blood was tested to determine low and average molecular-weight substances by spectrophotometry and the pro- and antioxidative systems by chemiluminescence. Pulmonary circulation arteries were morphologically studied in young animals, rats in the late posthemorrhagic period and old (24—25-month rats. Results. Sixty-minute hemorrhagic hypotension leads to the development of endotoxemia and imbalance of the pro- and antioxidative systems, the signs of which are observed in the late periods (2 months after hypotension. At the same time, the posthemorrhagic period is marked by the significant pulmonary circulation arterial morphological changes comparable with their age-related alterations in old rat. This shows up mainly in the reorganization of a connective tissue component in the vascular wall: the elevated levels of individual collagen fibers, their structural changes, elastic medial membrane destruction and deformity. At the same time, there is a change in the morphometric parameters of vessels at all study stages while their lowered flow capacity is only characteristic for intraorgan arteries. Conclusion: The increased activity of free radical oxidation and endotoxemia may be believed to be one of the causes of morphological changes in pulmonary circulation arteries in the late posthemorrhagic period, which is similar to age-related vascular alterations. Key words: hemorrhagic hypotension, pulmonary circulation arteries, free radical oxidation, endotoxemia, remodeling, late

[Effects of introduction of short peptides before carotid artery occlusion on behaviour and caspase-3 activity in the brain of old rats].

Science.gov (United States)

Mendzheritskiĭ, A M; Karantysh, G V; Ivonina, K O

2011-01-01

The comparative research of effect of Pinealon and Cortexin on behavior and activity of caspase-3 in a brain of old rats in a model of carotid arteries occlusion was conducted. It is shown that introduction of short peptides promotes a survival rate of the animals that have modeled occlusion of carotid arteries. Under Pinealon before occlusion of carotid arteries, behavioral dream has been increased and a position-finding behavior, a motivational behavior and a motor performance have been reduced. The rats that were introduced Cortexin before carotid arteries occlusion demonstrated the raise of behavioral dream time. At introduction of Pinealon activity of caspase-3 moderately raises in false-operated animals and in a model of occlusion of carotid arteries.

Pulsatility of Lenticulostriate Arteries Assessed by 7 Tesla Flow MRI-Measurement, Reproducibility, and Applicability to Aging Effect.

Science.gov (United States)

Schnerr, Roald S; Jansen, Jacobus F A; Uludag, Kamil; Hofman, Paul A M; Wildberger, Joachim E; van Oostenbrugge, Robert J; Backes, Walter H

2017-01-01

Characterization of flow properties in cerebral arteries with 1.5 and 3 Tesla MRI is usually limited to large cerebral arteries and difficult to evaluate in the small perforating arteries due to insufficient spatial resolution. In this study, we assessed the feasibility to measure blood flow waveforms in the small lenticulostriate arteries with 7 Tesla velocity-sensitive MRI. The middle cerebral artery was included as reference. Imaging was performed in five young and five old healthy volunteers. Flow was calculated by integrating time-varying velocity values over the vascular cross-section. MRI acquisitions were performed twice in each subject to determine reproducibility. From the flow waveforms, the pulsatility index and damping factor were deduced. Reproducibility values, in terms of the intraclass correlation coefficients, were found to be good to excellent. Measured pulsatility index of the lenticulostriate arteries significantly increased and damping factor significantly decreased with age. In conclusion, we demonstrate that blood flow through the lenticostriate arteries can be precisely measured using 7 Tesla MRI and reveal effects of arterial stiffness due to aging. These findings hold promise to provide relevant insights into the pathologies involving perforating cerebral arteries.

Stress-sensitive tissue regeneration in viscoelastic biomaterials subjected to modulated tensile strain.

Science.gov (United States)

Belfiore, Laurence A; Floren, Michael L; Paulino, Alexandre T; Belfiore, Carol J

2011-09-01

This research contribution addresses the mechanochemistry of intra-tissue mass transfer for nutrients, oxygen, growth factors, and other essential ingredients that anchorage-dependent cells require for successful proliferation on biocompatible surfaces. The unsteady state reaction-diffusion equation (i.e., modified diffusion equation) is solved according to the von Kármán-Pohlhausen integral method of boundary layer analysis when nutrient consumption and tissue regeneration are stimulated by harmonically imposed stress. The mass balance with diffusion and stress-sensitive kinetics represents a rare example where the Damköhler and Deborah numbers appear together in an effort to simulate the development of mass transfer boundary layers in porous viscoelastic biomaterials. The Boltzmann superposition integral is employed to calculate time-dependent strain in terms of the real and imaginary components of dynamic compliance for viscoelastic solids that transmit harmonic excitation to anchorage-dependent cells. Rates of nutrient consumption under stress-free conditions are described by third-order kinetics which include local mass densities of nutrients, oxygen, and attached cells that maintain dynamic equilibrium with active protein sites in the porous matrix. Thinner nutrient mass transfer boundary layers are stabilized at shorter dimensionless diffusion times when the stress-free intra-tissue Damköhler number increases above its initial-condition-sensitive critical value. The critical stress-sensitive intra-tissue Damköhler number, above which it is necessary to consider the effect of harmonic strain on nutrient consumption and tissue regeneration, is proportional to the Deborah number and corresponds to a larger fraction of the stress-free intra-tissue Damköhler number in rigid biomaterials. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparison of renal artery, soft tissue, and nerve damage after irrigated versus nonirrigated radiofrequency ablation.

Science.gov (United States)

Sakakura, Kenichi; Ladich, Elena; Fuimaono, Kristine; Grunewald, Debby; O'Fallon, Patrick; Spognardi, Anna-Maria; Markham, Peter; Otsuka, Fumiyuki; Yahagi, Kazuyuki; Shen, Kai; Kolodgie, Frank D; Joner, Michael; Virmani, Renu

2015-01-01

The long-term efficacy of radiofrequency ablation of renal autonomic nerves has been proven in nonrandomized studies. However, long-term safety of the renal artery (RA) is of concern. The aim of our study was to determine if cooling during radiofrequency ablation preserved the RA while allowing equivalent nerve damage. A total of 9 swine (18 RAs) were included, and allocated to irrigated radiofrequency (n=6 RAs, temperature setting: 50°C), conventional radiofrequency (n=6 RAs, nonirrigated, temperature setting: 65°C), and high-temperature radiofrequency (n=6 RAs, nonirrigated, temperature setting: 90°C) groups. RAs were harvested at 10 days, serially sectioned from proximal to distal including perirenal tissues and examined after paraffin embedding, and staining with hematoxylin-eosin and Movat pentachrome. RAs and periarterial tissue including nerves were semiquantitatively assessed and scored. A total of 660 histological sections from 18 RAs were histologically examined by light microscopy. Arterial medial injury was significantly less in the irrigated radiofrequency group (depth of medial injury, circumferential involvement, and thinning) than that in the conventional radiofrequency group (Pradiofrequency group (Pradiofrequency group and conventional radiofrequency group (P=0.36), there was a trend toward less nerve damage in the irrigated compared with conventional. Compared to conventional radiofrequency, circumferential medial damage in highest-temperature nonirrigated radiofrequency group was significantly greater (Pradiofrequency ablation, and there is a trend toward less nerve damage. © 2014 American Heart Association, Inc.

Systematic optimization of multiplex zymography protocol to detect active cathepsins K, L, S, and V in healthy and diseased tissue: compromise among limits of detection, reduced time, and resources.

Science.gov (United States)

Dumas, Jerald E; Platt, Manu O

2013-07-01

Cysteine cathepsins are a family of proteases identified in cancer, atherosclerosis, osteoporosis, arthritis, and a number of other diseases. As this number continues to rise, so does the need for low cost, broad use quantitative assays to detect their activity and can be translated to the clinic in the hospital or in low resource settings. Multiplex cathepsin zymography is one such assay that detects subnanomolar levels of active cathepsins K, L, S, and V in cell or tissue preparations observed as clear bands of proteolytic activity after gelatin substrate SDS-PAGE with conditions optimal for cathepsin renaturing and activity. Densitometric analysis of the zymogram provides quantitative information from this low cost assay. After systematic modifications to optimize cathepsin zymography, we describe reduced electrophoresis time from 2 h to 10 min, incubation assay time from overnight to 4 h, and reduced minimal tissue protein necessary while maintaining sensitive detection limits; an evaluation of the pros and cons of each modification is also included. We further describe image acquisition by Smartphone camera, export to Matlab, and densitometric analysis code to quantify and report cathepsin activity, adding portability and replacing large scale, darkbox imaging equipment that could be cost prohibitive in limited resource settings.

Systematic optimization of multiplex zymography protocol to detect active cathepsins K, L, S, and V in healthy and diseased tissue: compromise between limits of detection, reduced time, and resources

Science.gov (United States)

Dumas, Jerald E.; Platt, Manu O.

2013-01-01

Cysteine cathepsins are a family of proteases identified in cancer, atherosclerosis, osteoporosis, arthritis and a number of other diseases. As this number continues to rise, so does the need for low cost, broad use quantitative assays to detect their activity and can be translated to the clinic in the hospital or in low resource settings. Multiplex cathepsin zymography is one such assay that detects subnanomolar levels of active cathepsins K, L, S, and V in cell or tissue preparations observed as cleared bands of proteolytic activity after gelatin substrate SDS-PAGE with conditions optimal for cathepsin renaturing and activity. Densitometric analysis of the zymogram provides quantitative information from this low cost assay. After systematic modifications to optimize cathepsin zymography, we describe reduced electrophoresis time from 2 hours to 10 minutes, incubation assay time from overnight to 4 hours, and reduced minimal tissue protein necessary while maintaining sensitive detection limits; an evaluation of the pros and cons of each modification is also included. We further describe image acquisition by smartphone camera, export to Matlab, and densitometric analysis code to quantify and report cathepsin activity, adding portability and replacing large scale, darkbox imaging equipment that could be cost prohibitive in limited resource settings. PMID:23532386

Primary extracranial vertebral artery aneurysms.

Science.gov (United States)

Morasch, Mark D; Phade, Sachin V; Naughton, Peter; Garcia-Toca, Manuel; Escobar, Guillermo; Berguer, Ramon

2013-05-01

Extracranial vertebral artery aneurysms are uncommon and are usually associated with trauma or dissection. Primary cervical vertebral aneurysms are even rarer and are not well described. The presentation and natural history are unknown and operative management can be difficult. Accessing aneurysms at the skull base can be difficult and, because the frail arteries are often afflicted with connective tissue abnormalities, direct repair can be particularly challenging. We describe the presentation and surgical management of patients with primary extracranial vertebral artery aneurysms. In this study we performed a retrospective, multi-institutional review of patients with primary aneurysms within the extracranial vertebral artery. Between January 2000 and January 2011, 7 patients, aged 12-56 years, were noted to have 9 primary extracranial vertebral artery aneurysms. All had underlying connective tissue or another hereditary disorder, including Ehler-Danlos syndrome (n=3), Marfan's disease (n=2), neurofibromatosis (n=1), and an unspecified connective tissue abnormality (n=1). Eight of 9 aneurysms were managed operatively, including an attempted bypass that ultimately required vertebral ligation; the contralateral aneurysm on this patient has not been treated. Open interventions included vertebral bypass with vein, external carotid autograft, and vertebral transposition to the internal carotid artery. Special techniques were used for handling the anastomoses in patients with Ehler-Danlos syndrome. Although endovascular exclusion was not performed in isolation, 2 hybrid procedures were performed. There were no instances of perioperative stroke or death. Primary extracranial vertebral artery aneurysms are rare and occur in patients with hereditary disorders. Operative intervention is warranted in symptomatic patients. Exclusion and reconstruction may be performed with open and hybrid techniques with low morbidity and mortality. Copyright © 2013 Elsevier Inc. All rights

Biobanking for cancer research: Preservation of tissue integrity - Some technical considerations

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S K Shankar

2012-01-01

Full Text Available Biobanking and biomarker discovery have become an integral part of neuro-oncology research. Towards achieving this end, the essential requirement is optimizing methods of tissue preservation of human tissues removed at surgery for diagnostic purposes and banking them for subserving future research. Owing to recent advances in molecular diagnostic tools, this clinical material has become a precious source for proteomic and genomic studies. The advent of biotechnological tools such as microarray, proteomics, and genomics has made it essential to preserve not just morphology but also the quality of nucleic acids and proteins, changing the traditional workflow of a pathology laboratory. It is therefore essential to develop simple technologies for tissue fixation and storage ensure that receptor and molecular integrity is reasonably maintained. Knowledge of the basic chemistry of tissue fixatives, the biochemical changes that take place in biological material by utilizing different techniques of fixation is essential while undertaking molecular, genomic, and proteomic studies on fresh and archival tissues.

An Algorithmic Approach to Total Breast Reconstruction with Free Tissue Transfer

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Seong Cheol Yu

2013-05-01

Full Text Available As microvascular techniques continue to improve, perforator flap free tissue transfer is now the gold standard for autologous breast reconstruction. Various options are available for breast reconstruction with autologous tissue. These include the free transverse rectus abdominis myocutaneous (TRAM flap, deep inferior epigastric perforator flap, superficial inferior epigastric artery flap, superior gluteal artery perforator flap, and transverse/vertical upper gracilis flap. In addition, pedicled flaps can be very successful in the right hands and the right patient, such as the pedicled TRAM flap, latissimus dorsi flap, and thoracodorsal artery perforator. Each flap comes with its own advantages and disadvantages related to tissue properties and donor-site morbidity. Currently, the problem is how to determine the most appropriate flap for a particular patient among those potential candidates. Based on a thorough review of the literature and accumulated experiences in the author’s institution, this article provides a logical approach to autologous breast reconstruction. The algorithms presented here can be helpful to customize breast reconstruction to individual patient needs.

Transcutaneous measurement of the arterial input function in positron emission tomography

International Nuclear Information System (INIS)

Litton, J.E.; Eriksson, L.

1990-01-01

Positron emission tomography (PET) provides a powerful tool in medical research. Biochemical function can be both precisely localized and quantitatively measured. To achieve reliable quantitation it is necessary to know the time course of activity concentration in the arterial blood during the measurement. In this study the arterial blood curve from the brachial artery is compared to the activity measured in the internal carotid artery with a new transcutaneous detector

Evolution of shear stress, protein expression, and vessel area in an animal model of arterial dilatation in hemodialysis grafts

Science.gov (United States)

Misra, Sanjay; Fu, Alex A.; Misra, Khamal D.; Glockner, James F.; Mukhopadyay, Debabrata

2010-01-01

Purpose To evaluate the wall shear stress, protein expression of matrix metalloproteinases-2 (MMP-2), -9 (MMP-9), and the inhibitors (tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), and -2 (TIMP-2)), and vessel area over time in a porcine model for hemodialysis polytetrafluoroethylene (PTFE) grafts. Materials and methods In 21 pigs, subtotal renal infarction was performed and 28 days later, a PTFE graft was placed to connect the carotid artery to the ipsilateral jugular vein. Phase contrast MR was used to measure blood flow and vessel area at 1, 3, 7, and 14 days after graft placement. Wall shear stress was estimated from Poiseuille’s law. Animals were sacrificed at day 3 (N=7), day 7 (N=7), and day 14 (N=7) and expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 were determined at the grafted and control arteries. Results The mean wall shear stress of the grafted artery was higher than the control artery at all time points (P<0.05). It peaked by day 3 and decreased by days 7–14 as the vessel area nearly doubled. By days 7–14, there was a significant increase in active MMP-2 followed by a significant increase in pro and active MMP-9 by day 14 (P<0.05, grafted artery versus control). TIMP-1 expression peaked by day 7 and then decreased while TIMP-2 expression was decreased at days 7–14. Conclusions The wall shear stress of the grafted artery peaks by day 3 with increased MMP-2 activity by days 7–14 followed by pro and active MMP-9 by day 14 and the vessel area nearly doubled. PMID:20123196

Real-time in vivo tissue characterization with diffuse reflectance spectroscopy during transthoracic lung biopsy: a clinical feasibility study

NARCIS (Netherlands)

Spliethoff, Jarich; Prevoo, Warner; Meier, Mark A.J.; de Jong, Jeroen; Evers, Daniel; Evers, Daniel J.; Sterenborg, Hendricus J.C.M.; Lucassen, Gerald; Lucassen, Gerald W.; Hendriks, Benno H.W.; Ruers, Theo J.M.

2016-01-01

Purpose: This study presents the first in vivo real-time tissue characterization during image-guided percutaneous lung biopsies using diffuse reflectance spectroscopy (DRS) sensing at the tip of a biopsy needle with integrated optical fibers. Experimental Design: Tissues from 21 consented patients

Correlation between the dielectric properties and biological activities of human ex vivo hepatic tissue

International Nuclear Information System (INIS)

Wang, Hang; You, Fusheng; Fu, Feng; Dong, Xiuzhen; Shi, Xuetao; He, Yong; Yang, Min; Yan, Qingguo

2015-01-01

Dielectric properties are vital biophysical features of biological tissues, and biological activity is an index to ascertain the active state of tissues. This study investigated the potential correlation between the dielectric properties and biological activities of human hepatic tissue with prolonged ex vivo time through correlation and regression analyses. The dielectric properties of 26 cases of normal human hepatic tissue at 10 Hz to 100 MHz were measured from 15 min after isolation to 24 h at 37 °C with 90% humidity. Cell morphologies, including nucleus area (NA) and alteration rate of intercellular area (ICAR), were analyzed as indicators of biological activities. Conductivity, complex resistivity, and NA exhibited opposing changes 1 h after isolation. Relative permittivity and ex vivo time were not closely correlated (p > 0.05). The dielectric properties measured at low frequencies (i.e. <1 MHz) were more sensitive than those measured at high frequencies in reflecting the biological activity of ex vivo tissue. Highly significant correlations were found between conductivity, resistivity and the ex vivo time (p < 0.05) as well as conductivity and the cell morphology (p < 0.05). The findings indicated that establishing the correlation between the dielectric properties and biological activities of human hepatic tissue is of great significance for promoting the role of dielectric properties in biological science, particularly in human biology. (paper)

Effect of transcervical resection of adhesion combined with low-dose aspirin on uterine artery blood flow and Smad2/3 in endometrial tissue

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Qian-Wen Chen

2016-11-01

Full Text Available Objective: To study the effect of transcervical resection of adhesion combined with lowdose aspirin on uterine artery blood flow and Smad2/3 in endometrial tissue. Methods: A total of 78 patients with severe intrauterine adhesions who received transcervical resection of adhesion in our hospital between June 2012 and October 2014 were prospectively studied and randomly divided into two groups, observation group received postoperative estrogenprogestogen combined with low-dose aspirin therapy, and control group received postoperative estrogen-progestogen therapy. Ultrasound examination was conducted before and after treatment to determine uterine artery and endometrial blood flow parameters, intrauterine adhesion tissue was collected to detect the expression levels of Smad2 and Smad3 as well as downstream molecules, and serum was collected to determine the levels of cytokines. Results: On the ovulation day after 3 cycles of treatment, uterine artery RI and PI of observation group were significantly lower than those of control group, and endometrial VI, FI and VFI were significantly higher than those of control group; uPA expression level in intrauterine adhesion tissue of observation group was significantly higher than that of control group, Smad2, Smad3, PAI-1, ADAM15 and ADAM17 expression levels were significantly lower than those of control group, and serum TGF-β, VEGF, CTGF, IGF-I and TNF-α levels were significantly lower than those of control group. Conclusions: Transcervical resection of adhesion combined with low-dose aspirin therapy can improve the postoperative uterine artery and endometrial blood flow state, inhibit extracellular matrix deposition mediated by Smad2/3 signaling pathway and prevent intrauterine re-adhesion in patients with intrauterine adhesions.

Temporary Arterial Embolization of Liver Parenchyma with Degradable Starch Microspheres (EmboCept{sup ®}S) in a Swine Model

Energy Technology Data Exchange (ETDEWEB)

Pieper, Claus C., E-mail: claus.christian.pieper@ukb.uni-bonn.de; Meyer, Carsten, E-mail: Carsten.Meyer@ukb.uni-bonn.de [University of Bonn, Department of Radiology (Germany); Vollmar, Brigitte, E-mail: brigitte.vollmar@med.uni-rostock.de [University of Rostock, Institute for Experimental Surgery (Germany); Hauenstein, Karlheinz, E-mail: karlheinz.hauenstein@med.uni-rostock.de [University of Rostock, Department of Diagnostic and Interventional Radiology (Germany); Schild, Hans H., E-mail: Hans.Schild@ukb.uni-bonn.de [University of Bonn, Department of Radiology (Germany); Wilhelm, Kai E., E-mail: Kai.Wilhelm@ek-bonn.de [Johanniter Hospital, Evangelische Kliniken Bonn (Germany)

2015-04-15

BackgroundThis study aimed to evaluate the embolic properties, time to reperfusion, and histologic changes in temporary embolization of liver tissue with degradable starch microspheres (DSM) in a swine model.MethodsIn four adult minipigs, DSMs were injected into the right or left hepatic artery on the lobar level until complete stasis of the blood flow was detectable angiographically. The time required to complete angiographically determined reperfusion was noted. The animals were killed 3 h after complete reperfusion, and samples were taken from the liver. Histologic examinations of the embolized liver parenchyma and untreated tissue were performed.ResultsHepatic arterial embolization using DSMs was technically successful in all cases, with complete blood flow stasis shown by control angiography. A single vial of DSMs (450 mg/7.5 ml) was sufficient to embolize a whole liver lobe in all cases. Angiography showed complete reconstitution of hepatic arterial perfusion after a mean time to reperfusion of 32 ± 6.1 min (range, 26–39 min). Hematoxylin and eosin staining showed no histologically detectable differences between untreated tissue and parenchyma embolized with DSMs except for mild sinusoidal congestion in one case. Indirect in situ DNA nick end labeling staining (TUNEL) showed only single positive hepatocytes, indicating apoptosis.ConclusionTemporary embolization of the hepatic artery using DSMs is feasible with complete reperfusion after 30 min in pigs. Even after complete arterial blood flow stasis, no extensive tissue damage to the embolized liver parenchyma was observed at histologic examinations in this short-term study.

Use of focused ultrasonication in activity-based profiling of deubiquitinating enzymes in tissue.

Science.gov (United States)

Nanduri, Bindu; Shack, Leslie A; Rai, Aswathy N; Epperson, William B; Baumgartner, Wes; Schmidt, Ty B; Edelmann, Mariola J

2016-12-15

To develop a reproducible tissue lysis method that retains enzyme function for activity-based protein profiling, we compared four different methods to obtain protein extracts from bovine lung tissue: focused ultrasonication, standard sonication, mortar & pestle method, and homogenization combined with standard sonication. Focused ultrasonication and mortar & pestle methods were sufficiently effective for activity-based profiling of deubiquitinases in tissue, and focused ultrasonication also had the fastest processing time. We used focused-ultrasonicator for subsequent activity-based proteomic analysis of deubiquitinases to test the compatibility of this method in sample preparation for activity-based chemical proteomics. Copyright © 2016 Elsevier Inc. All rights reserved.

Skin autofluorescence is increased in patients with carotid artery stenosis and peripheral artery disease

NARCIS (Netherlands)

Noordzij, Marjon J.; Lefrandt, Joop D.; Loeffen, Erik A. H.; Saleem, Ben R.; Meerwaldt, Robbert; Lutgers, Helen L.; Smit, Andries J.; Zeebregts, Clark J.

Advanced glycation end products (AGEs) have a pivotal role in atherosclerosis. We evaluated skin autofluorescence (SAF), a non-invasive measurement of tissue AGE accumulation, in patients with carotid artery stenosis with and without coexisting peripheral artery occlusive disease (PAOD). SAF was

WE-FG-206-05: New Arterial Spin Labeling Method for Simultaneous Estimation of Arterial Cerebral Blood Volume, Cerebral Blood Flow and Arterial Transit Time

Energy Technology Data Exchange (ETDEWEB)

Johnston, M; Whitlow, C; Jung, Y [Wake Forest School of Medicine, Winston-Salem, NC (United States); Liu, H [UT MD Anderson Cancer Center, Houston, TX (United States)

2016-06-15

Purpose: To demonstrate the feasibility of a novel Arterial Spin Labeling (ASL) method for simultaneously measuring cerebral blood flow (CBF), arterial transit time (ATT), and arterial cerebral blood volume (aCBV) without the use of a contrast agent. Methods: A series of multi-TI ASL images were acquired from one healthy subject on a 3T Siemens Skyra, with the following parameters: PCASL labeling with variable TI [300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000] ms, labeling bolus 1400 ms when TI allows, otherwise 100 ms less than TI, TR was minimized for each TI, two sinc shaped pre-saturation pulses were applied in the imaging plane immediately before 2D EPI acquisition. 64×64×24 voxels, 5 mm slice thickness, 1 mm gap, full brain coverage, 6 averages per TI, no crusher gradients, 11 ms TE, scan time of 4:56. The perfusion weighted time-series was created for each voxel and fit to a novel model. The model has two components: 1) the traditional model developed by Buxton et al., accounting for CBF and ATT, and 2) a box car function characterizing the width of the labeling bolus, with variable timing and height in proportion to the aCBV. All three parameters were fit using a nonlinear fitting routine that constrained all parameters to be positive. The main purpose of the high-temporal resolution TI sampling for the first second of data acquisition was to precisely estimate the blood volume component for better detection of arrival time and magnitude of signal. Results: Whole brain maps of CBF, ATT, and aCBV were produced, and all three parameters maps are consistent with similar maps described in the literature. Conclusion: Simultaneous mapping of CBF, ATT, and aCBV is feasible with a clinically tractable scan time (under 5 minutes).

Role of Doppler ultrasonography evaluation of superior mesenteric artery flow volume in the assessment of Crohn's disease activity

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Fabiana Paiva Martins

2013-09-01

Full Text Available Objective To investigate superior mesenteric artery flow measurement by Doppler ultrasonography as a means of characterizing inflammatory activity in Crohn's disease. Materials and Methods Forty patients were examined and divided into two groups – disease activity and remission – according to their Crohn's disease activity index score. Mean superior mesenteric artery flow volume was calculated for each group and correlated with Crohn's disease activity index score. Results The mean superior mesenteric artery flow volume was significantly greater in the patients with active disease (626 ml/min ± 236 × 376 ml/min ± 190; p = 0.001. As a cut off corresponding to 500 ml/min was utilized, the superior mesenteric artery flow volume demonstrated sensitivity of 83% and specificity of 82% for the diagnosis of Crohn's disease activity. Conclusion The present results suggest that patients with active Crohn's disease have increased superior mesenteric artery flow volume as compared with patients in remission. Superior mesenteric artery flow measurement had a good performance in the assessment of disease activity in this study sample.

An integrated sample preparation to determine coccidiostats and emerging Fusarium-mycotoxins in various poultry tissues with LC-MS/MS.

Science.gov (United States)

Jestoi, Marika; Rokka, Mervi; Peltonen, Kimmo

2007-05-01

The usefulness of an existing sample preparation technique used for ionophoric coccidiostats (lasalocid, monensin, salinomycin and narasin) was applied in the analysis of emerging Fusarium-mycotoxins beauvericin (BEA) and enniatins (ENNs) in poultry tissues (liver and meat). Also, maduramicin and liver as a new sample matrix was introduced. The developed methods were validated and applied for the determination of coccidiostats and BEA/ENNs in Finnish poultry tissues in 2004-2005. The validation parameters demonstrated that the integrated sample preparation technique is applicable to the parallel determination of these contaminants in poultry tissues. Of the samples analysed (276 meat and 43 liver), only trace levels of LAS, MON, SAL, NAR and MAD were detected in 7, 3, 5, 6 and 4% of the samples, respectively. Interestingly, for the first time, traces of BEA and ENNs could also be detected in animal tissues. BEA and ENNs A, A1, B and B1 were found in 2, 0.3, 0.6, 4 and 3% of the samples, respectively. The simultaneous presence of coccidiostats and mycotoxins was detected in three turkey samples in 2004.

Comparison of the effects of streptokinase and tissue plasminogen activator on regional wall motion after first myocardial infarction: analysis by the centerline method with correction for area at risk.

Science.gov (United States)

Cross, D B; Ashton, N G; Norris, R M; White, H D

1991-04-01

In a trial of streptokinase versus recombinant tissue-type plasminogen activator (rt-PA) for a first myocardial infarction, 270 patients were randomized. Regional left ventricular function was assessed in 214 patients at 3 weeks. The infarct-related artery was the left anterior descending artery in 78 patients, the right coronary artery in 122 and a dominant left circumflex artery in 14. Analysis was by the centerline method with a novel correction for the area of myocardium at risk, whereby the search region was determined by the anatomic distribution of the infarct-related artery. Infarct-artery patency at 3 weeks was 73% in the streptokinase group and 71% in the rt-PA group. Global left ventricular function did not differ between the two groups. Mean chord motion (+/- SD) in the most hypokinetic half of the defined search region was similar in the streptokinase and rt-PA groups (-2.4 +/- 1.5 versus -2.3 +/- 1.3, p = 0.63). There were no differences in hyperkinesia of the noninfarct zone. Compared with conventional centerline analysis, regional wall motion in the defined area at risk was significantly more abnormal. The two methods correlated strongly, however (r = 0.99, p less than 0.0001), and both methods produced similar overall results. Patients with a patent infarct-related artery and those with an occluded artery at the time of catheterization had similar levels of global function (ejection fraction 58 +/- 12% versus 57 +/- 12%, p = 0.58).(ABSTRACT TRUNCATED AT 250 WORDS)

Doses to Carotid Arteries After Modern Radiation Therapy for Hodgkin Lymphoma

DEFF Research Database (Denmark)

Maraldo, M.V.; Brodin, Nils Patrik; Aznar, Marianne Camille

2013-01-01

Hodgkin lymphoma (HL) survivors are at an increased risk of stroke because of carotid artery irradiation. However, for early-stage HL involved node radiation therapy (INRT) reduces the volume of normal tissue exposed to high doses. Here, we evaluate 3-dimensional conformal radiation therapy (3D......-CRT), volumetric-modulated arc therapy (VMAT), and proton therapy (PT) delivered as INRT along with the extensive mantle field (MF) by comparing doses to the carotid arteries and corresponding risk estimates....

Epicardial and Subcutaneous Adipose Tissue Fatty Acids Profiles in Diabetic and Non-Diabetic Patients Candidate for Coronary Artery Bypass Graft

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Masoud Pezeshkian

2013-01-01

Full Text Available Introduction: We have recently shown that in high cholesterol-fed rabbits, the sensitivity of epicardial adipose tissue to changes in dietary fat is higher than that of subcutaneous adipose tissue. Although the effects of diabetes on epicardial adipose tissue thickness have been studied, the influence of diabetes on profile of epicardial free fatty acids (FFAs has not been studied. The aim of this study is to investigate the effect of diabetes on the FFAs composition in serum and in the subcutaneous and epicardial adipose tissues in patients undergoing coronary artery bypass graft (CABG. Methods: Forty non-diabetic and twenty eight diabetic patients candidate for CABG with > 75% stenosis participated in this study.Fasting blood sugar (FBS and lipid profiles were assayed by auto analyzer. Phospholipids and non-estrified FFA of serum and the fatty acids profile of epicardial and subcutaneous adipose tissues were determined using gas chromatography method. Results: In the phospholipid fraction of diabetic patients’ serum, the percentage of 16:0, 18:3n-9, 18:2n-6 and monounsaturated fatty acids (MUFAs was lower than the corresponding values of the non-diabetics; whereas, 18:0 value was higher. A 100% increase in the amount of 18:0 and 35% decrease in the level of 18:1n-11 was observed in the diabetic patients’ subcutaneous adipose tissue. In epicardial adipose tissue, the increase of 18:0 and conjugated linolenic acid (CLA and decrease of 18:1n-11, ω3 (20:5n-3 and 22:6n-3 were significant; but, the contents of arachidonic acid and its precursor linoleic acid were not affected by diabetes. Conclusion: The fatty acids’ profile of epicardial and subcutaneous adipose tissues is not equally affected by diabetes. The significant decrease of 16:0 and ω3 fatty acids and increase of trans and conjugated fatty acids in epicardial adipose tissue in the diabetic patients may worsen the formation of atheroma in the related arteries.

Fit for purpose frozen tissue collections by RNA integrity number-based quality control assurance at the Erasmus MC tissue bank.

Science.gov (United States)

Kap, Marcel; Oomen, Monique; Arshad, Shazia; de Jong, Bas; Riegman, Peter

2014-04-01

About 5000 frozen tissue samples are collected each year by the Erasmus Medical Center tissue bank. Two percent of these samples are randomly selected annually for RNA isolation and RNA Integrity Number (RIN) measurement. A similar quality assessment was conducted during centralization of a 20-year-old tissue collection from the cancer institute, a 15-year-old liver sample archive (-80°C), and a 13-year-old clinical pathology frozen biopsy archive (Liquid Nitrogen). Samples were divided into either high-quality (RIN ≥6.5) or low-quality overall categories, or into four "fit-for-purpose" quality groups: RIN procurement protocols used for these samples needed immediate evaluation. When the distribution of RIN values of the different collections were compared, no significant differences were found, despite differences in average storage time and temperature. According to the principle of "fit-for-purpose" distribution, the vast majority of samples are considered good enough for most downstream techniques. In conclusion, an annual tissue bank quality control procedure provides useful information on tissue sample quality and sheds light on where and if improvements need to be made.

Studies on reconstruction of the carotid artery in the neck using arterial vessels irradiated by a large amount of high voltage electron beam

International Nuclear Information System (INIS)

Matsumura, Hiroshi

1978-01-01

High voltage electron beam of 2,000,000 rad was irradiated to the common carotid arteries excised from dogs. After keeping them in a frozen state, they were replaced with the common carotid arteries of other adult dogs. The border of the artery transplanted could not be identified from the x-ray films 7 - 36 months after transplantation. There was no stenosis or dilation in the artery on either x-ray films or in histopathological examinations. There was no tissue reaction in the homologous transplantation, but all the cells died and the nuclei of muscular fibers of the tunica media disappeared. However, the internal elastica and other elastic fibers were unchanged. Cells proliferated from the original artery to form a false inner coat. Noradrenergic nerves and the vasa vasorum did not enter the graft. Thus, the arteries transplanted were only substitutive vessels. A rabbit abdominal aorta which was transplanted to a dog common carotid artery, showed sacculated dilation or obstruction. In the case of obstruction, severe tissue reaction was recognized. In the case of sacculated dilation, thinning of the arterial wall at the dilated part and fragmentation of the elastic fibers of the tunica media were observed, and other tissues also tended to be destructed and absorbed. (Ichikawa, K.)

Real-time simulation of the nonlinear visco-elastic deformations of soft tissues.

Science.gov (United States)

Basafa, Ehsan; Farahmand, Farzam

2011-05-01

Mass-spring-damper (MSD) models are often used for real-time surgery simulation due to their fast response and fairly realistic deformation replication. An improved real time simulation model of soft tissue deformation due to a laparoscopic surgical indenter was developed and tested. The mechanical realization of conventional MSD models was improved using nonlinear springs and nodal dampers, while their high computational efficiency was maintained using an adapted implicit integration algorithm. New practical algorithms for model parameter tuning, collision detection, and simulation were incorporated. The model was able to replicate complex biological soft tissue mechanical properties under large deformations, i.e., the nonlinear and viscoelastic behaviors. The simulated response of the model after tuning of its parameters to the experimental data of a deer liver sample, closely tracked the reference data with high correlation and maximum relative differences of less than 5 and 10%, for the tuning and testing data sets respectively. Finally, implementation of the proposed model and algorithms in a graphical environment resulted in a real-time simulation with update rates of 150 Hz for interactive deformation and haptic manipulation, and 30 Hz for visual rendering. The proposed real time simulation model of soft tissue deformation due to a laparoscopic surgical indenter was efficient, realistic, and accurate in ex vivo testing. This model is a suitable candidate for testing in vivo during laparoscopic surgery.

Unruptured Cerebral Aneurysm Detected after Intravenous Tissue Plasminogen Activator for Stroke

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Yukihiro Yoneda

2009-06-01

Full Text Available Therapeutic guidelines of intravenous thrombolysis with tissue plasminogen activator (tPA for hyperacute ischemic stroke are very strict. Because of potential higher risk of bleeding complications, the presence of unruptured cerebral aneurysm is a contraindication for systemic thrombolysis with tPA. According to the standard CT criteria, a 66-year-old woman who suddenly developed aphasia and hemiparesis received intravenous tPA within 3 h after ischemic stroke. Magnetic resonance angiography during tPA infusion was performed and the presence of a small unruptured cerebral aneurysm was suspected at the anterior communicating artery. Delayed cerebral angiography confirmed an aneurysm with a size of 7 mm. The patient did not experience any adverse complications associated with the aneurysm. Clinical experiences of this kind of accidental off-label thrombolysis may contribute to modify the current rigid tPA guidelines for stroke.

Evidence for an enduring ischaemic penumbra following central retinal artery occlusion, with implications for fibrinolytic therapy.

Science.gov (United States)

McLeod, David; Beatty, Stephen

2015-11-01

The rationale behind hyperacute fibrinolytic therapy for cerebral and retinal arterial occlusion is to rescue ischaemic cells from irreversible damage through timely restitution of tissue perfusion. In cerebral stroke, an anoxic tissue compartment (the "infarct core") is surrounded by a hypoxic compartment (the "ischaemic penumbra"). The latter comprises electrically-silent neurons that undergo delayed apoptotic cell death within 1-6 h unless salvaged by arterial recanalisation. Establishment of an equivalent hypoxic compartment within the inner retina following central retinal artery occlusion (CRAO) isn't widely acknowledged. During experimental CRAO, electroretinography reveals 3 oxygenation-based tissue compartments (anoxic, hypoxic and normoxic) that contribute 32%, 27% and 41% respectively to the pre-occlusion b-wave amplitude. Thus, once the anoxia survival time (≈2 h) expires, the contribution from the infarcted posterior retina is irreversibly extinguished, but electrical activity continues in the normoxic periphery. Inbetween these compartments, an annular hypoxic zone (the "penumbra obscura") endures in a structurally-intact but functionally-impaired state until retinal reperfusion allows rapid recovery from electrical silence. Clinically, residual circulation of sufficient volume flow rate generates the heterogeneous fundus picture of "partial" CRAO. Persistent retinal venous hypoxaemia signifies maximal extraction of oxygen by an enduring "polar penumbra" that permeates or largely replaces the infarct core. On retinal reperfusion some days later, the retinal venous oxygen saturation reverts to normal and vision improves. Thus, penumbral inner retina, marginally oxygenated by the choroid or by residual circulation, isn't at risk of delayed apoptotic infarction (unlike hypoxic cerebral cortex). Emergency fibrinolytic intervention is inappropriate, therefore, once the duration of CRAO exceeds 2 h. Copyright © 2015 Elsevier Ltd. All rights reserved.

Contribution of α-adrenoceptors to depolarization and contraction evoked by continuous asynchronous sympathetic nerve activity in rat tail artery

Science.gov (United States)

Brock, J A; McLachlan, E M; Rayner, S E

1997-01-01

The effects of continuous but asynchronous nerve activity induced by ciguatoxin (CTX-1) on the membrane potential and contraction of smooth muscle cells have been investigated in rat proximal tail arteries isolated in vitro. These effects have been compared with those produced by the continuous application of phenylephrine (PE).CTX-1 (0.4 nM) and PE (10 μM) produced a maintained depolarization of the arterial smooth muscle that was almost completely blocked by α-adrenoceptor blockade. In both cases, the depolarization was more sensitive to the selective α2-adrenoceptor antagonist, idazoxan (0.1 μM), than to the selective α1-adrenoceptor antagonist, prazosin (0.01 μM).In contrast, the maintained contraction of the tail artery induced by CTX-1 (0.2 nM) and PE (2 and 10 μM) was more sensitive to prazosin (0.01) μM, than to idazoxan (0.01 μM). In combination, these antagonists almost completely inhibited contraction to both agents.Application of the calcium channel antagonist, nifedipine (1 μM), had no effect on the depolarization induced by either CTX-1 or PE but maximally reduced the force of the maintained contraction to both agents by about 50%.We conclude that the constriction of the tail artery induced by CTX-1, which mimics the natural discharge of postganglionic perivascular axons, is due almost entirely to α-adrenoceptor activation. The results indicate that neuronally released noradrenaline activates more than one α-adrenoceptor subtype. The depolarization is dependent primarily on α2-adrenoceptor activation whereas the contraction is dependent primarily on α1-adrenoceptor activation. The links between α-adrenoceptor activation and the voltage-dependent and voltage-independent mechanisms that deliver Ca2+ to the contractile apparatus appear to be complex. PMID:9113373

Time-symmetric integration in astrophysics

Science.gov (United States)

Hernandez, David M.; Bertschinger, Edmund

2018-04-01

Calculating the long-term solution of ordinary differential equations, such as those of the N-body problem, is central to understanding a wide range of dynamics in astrophysics, from galaxy formation to planetary chaos. Because generally no analytic solution exists to these equations, researchers rely on numerical methods that are prone to various errors. In an effort to mitigate these errors, powerful symplectic integrators have been employed. But symplectic integrators can be severely limited because they are not compatible with adaptive stepping and thus they have difficulty in accommodating changing time and length scales. A promising alternative is time-reversible integration, which can handle adaptive time-stepping, but the errors due to time-reversible integration in astrophysics are less understood. The goal of this work is to study analytically and numerically the errors caused by time-reversible integration, with and without adaptive stepping. We derive the modified differential equations of these integrators to perform the error analysis. As an example, we consider the trapezoidal rule, a reversible non-symplectic integrator, and show that it gives secular energy error increase for a pendulum problem and for a Hénon-Heiles orbit. We conclude that using reversible integration does not guarantee good energy conservation and that, when possible, use of symplectic integrators is favoured. We also show that time-symmetry and time-reversibility are properties that are distinct for an integrator.

Adipose tissue and skeletal muscle blood flow during mental stress

Energy Technology Data Exchange (ETDEWEB)

Linde, B.; Hjemdahl, P.; Freyschuss, U.; Juhlin-Dannfelt, A.

1989-01-01

Mental stress (a modified Stroop color word conflict test (CWT)) increased adipose tissue blood flow (ATBF; 133Xe clearance) by 70% and reduced adipose tissue vascular resistance (ATR) by 25% in healthy male volunteers. The vasculatures of adipose tissue (abdomen as well as thigh), skeletal muscle of the calf (133Xe clearance), and the entire calf (venous occlusion plethysmography) responded similarly. Arterial epinephrine (Epi) and glycerol levels were approximately doubled by stress. Beta-Blockade by metoprolol (beta 1-selective) or propranolol (nonselective) attenuated CWT-induced tachycardia similarly. Metoprolol attenuated stress-induced vasodilation in the calf and tended to do so in adipose tissue. Propranolol abolished vasodilation in the calf and resulted in vasoconstriction during CWT in adipose tissue. Decreases in ATR, but not in skeletal muscle or calf vascular resistances, were correlated to increases in arterial plasma glycerol (r = -0.42, P less than 0.05), whereas decreases in skeletal muscle and calf vascular resistances, but not in ATR, were correlated to increases in arterial Epi levels (r = -0.69, P less than 0.01; and r = -0.43, P less than 0.05, respectively). The results suggest that mental stress increases nutritive blood flow in adipose tissue and skeletal muscle considerably, both through the elevation of perfusion pressure and via vasodilatation. Withdrawal of vasoconstrictor nerve activity, vascular beta 2-adrenoceptor stimulation by circulating Epi, and metabolic mechanisms (in adipose tissue) may contribute to the vasodilatation.

Adipose tissue and skeletal muscle blood flow during mental stress

International Nuclear Information System (INIS)

Linde, B.; Hjemdahl, P.; Freyschuss, U.; Juhlin-Dannfelt, A.

1989-01-01

Mental stress [a modified Stroop color word conflict test (CWT)] increased adipose tissue blood flow (ATBF; 133Xe clearance) by 70% and reduced adipose tissue vascular resistance (ATR) by 25% in healthy male volunteers. The vasculatures of adipose tissue (abdomen as well as thigh), skeletal muscle of the calf (133Xe clearance), and the entire calf (venous occlusion plethysmography) responded similarly. Arterial epinephrine (Epi) and glycerol levels were approximately doubled by stress. Beta-Blockade by metoprolol (beta 1-selective) or propranolol (nonselective) attenuated CWT-induced tachycardia similarly. Metoprolol attenuated stress-induced vasodilation in the calf and tended to do so in adipose tissue. Propranolol abolished vasodilation in the calf and resulted in vasoconstriction during CWT in adipose tissue. Decreases in ATR, but not in skeletal muscle or calf vascular resistances, were correlated to increases in arterial plasma glycerol (r = -0.42, P less than 0.05), whereas decreases in skeletal muscle and calf vascular resistances, but not in ATR, were correlated to increases in arterial Epi levels (r = -0.69, P less than 0.01; and r = -0.43, P less than 0.05, respectively). The results suggest that mental stress increases nutritive blood flow in adipose tissue and skeletal muscle considerably, both through the elevation of perfusion pressure and via vasodilatation. Withdrawal of vasoconstrictor nerve activity, vascular beta 2-adrenoceptor stimulation by circulating Epi, and metabolic mechanisms (in adipose tissue) may contribute to the vasodilatation

Systemic Arterial-to-Pulmonary Artery Shunt Utilization

African Journals Online (AJOL)

multiruka1

In certain circumstances, such as cyanotic neonates with tetralogy of Fallot (4) or cyanotic patients with. Tetralogy of Fallot and hypoplastic pulmonary arteries. (5), better outcomes are obtained if definitive surgery. (total correction or palliation) is preceded by creation of a systemic arterial-to-pulmonary artery shunt (SAPAS).

The future of collateral artery research

NARCIS (Netherlands)

Hakimzadeh, Nazanin; Verberne, Hein J.; Siebes, Maria; Piek, Jan J.

2014-01-01

In the event of obstructive coronary artery disease, collateral arteries have been deemed an alternative blood source to preserve myocardial tissue perfusion and function. Monocytes play an important role in modulating this process, by local secretion of growth factors and extracellular matrix

Transit time corrected arterial spin labeling technique aids to overcome delayed transit time effect

International Nuclear Information System (INIS)

Yun, Tae Jin; Sohn, Chul-Ho; Yoo, Roh-Eul; Kang, Kyung Mi; Choi, Seung Hong; Kim, Ji-hoon; Park, Sun-Won; Hwang, Moonjung; Lebel, R.M.

2018-01-01

This study aimed to evaluate the usefulness of transit time corrected cerebral blood flow (CBF) maps based on multi-phase arterial spin labeling MR perfusion imaging (ASL-MRP). The Institutional Review Board of our hospital approved this retrospective study. Written informed consent was waived. Conventional and multi-phase ASL-MRPs and dynamic susceptibility contrast MR perfusion imaging (DSC-MRP) were acquired for 108 consecutive patients. Vascular territory-based volumes of interest were applied to CBF and time to peak (TTP) maps obtained from DSC-MRP and CBF maps obtained from conventional and multi-phase ASL-MRPs. The concordances between normalized CBF (nCBF) from DSC-MRP and nCBF from conventional and transition time corrected CBF maps from multi-phase ASL-MRP were evaluated using Bland-Altman analysis. In addition, the dependence of difference between nCBF (ΔnCBF) values obtained from DSC-MRP and conventional ASL-MRP (or multi-phase ASL-MRP) on TTP obtained from DSC-MRP was also analyzed using regression analysis. The values of nCBFs from conventional and multi-phase ASL-MRPs had lower values than nCBF based on DSC-MRP (mean differences, 0.08 and 0.07, respectively). The values of ΔnCBF were dependent on TTP values from conventional ASL-MRP technique (F = 5.5679, P = 0.0384). No dependency of ΔnCBF on TTP values from multi-phase ASL-MRP technique was revealed (F = 0.1433, P > 0.05). The use of transit time corrected CBF maps based on multi-phase ASL-MRP technique can overcome the effect of delayed transit time on perfusion maps based on conventional ASL-MRP. (orig.)

Transit time corrected arterial spin labeling technique aids to overcome delayed transit time effect

Energy Technology Data Exchange (ETDEWEB)

Yun, Tae Jin; Sohn, Chul-Ho; Yoo, Roh-Eul; Kang, Kyung Mi; Choi, Seung Hong; Kim, Ji-hoon [Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Park, Sun-Won [Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University Boramae Medical Center, Department of Radiology, Seoul (Korea, Republic of); Hwang, Moonjung [GE Healthcare Korea, Seoul (Korea, Republic of); Lebel, R.M. [GE Healthcare Canada, Calgary (Canada)

2018-03-15

This study aimed to evaluate the usefulness of transit time corrected cerebral blood flow (CBF) maps based on multi-phase arterial spin labeling MR perfusion imaging (ASL-MRP). The Institutional Review Board of our hospital approved this retrospective study. Written informed consent was waived. Conventional and multi-phase ASL-MRPs and dynamic susceptibility contrast MR perfusion imaging (DSC-MRP) were acquired for 108 consecutive patients. Vascular territory-based volumes of interest were applied to CBF and time to peak (TTP) maps obtained from DSC-MRP and CBF maps obtained from conventional and multi-phase ASL-MRPs. The concordances between normalized CBF (nCBF) from DSC-MRP and nCBF from conventional and transition time corrected CBF maps from multi-phase ASL-MRP were evaluated using Bland-Altman analysis. In addition, the dependence of difference between nCBF (ΔnCBF) values obtained from DSC-MRP and conventional ASL-MRP (or multi-phase ASL-MRP) on TTP obtained from DSC-MRP was also analyzed using regression analysis. The values of nCBFs from conventional and multi-phase ASL-MRPs had lower values than nCBF based on DSC-MRP (mean differences, 0.08 and 0.07, respectively). The values of ΔnCBF were dependent on TTP values from conventional ASL-MRP technique (F = 5.5679, P = 0.0384). No dependency of ΔnCBF on TTP values from multi-phase ASL-MRP technique was revealed (F = 0.1433, P > 0.05). The use of transit time corrected CBF maps based on multi-phase ASL-MRP technique can overcome the effect of delayed transit time on perfusion maps based on conventional ASL-MRP. (orig.)

A simple method for regional cerebral blood flow measurement by one-point arterial blood sampling and 123I-IMP microsphere model (part 2). A study of time correction of one-point blood sample count

International Nuclear Information System (INIS)

Masuda, Yasuhiko; Makino, Kenichi; Gotoh, Satoshi

1999-01-01

In our previous paper regarding determination of the regional cerebral blood flow (rCBF) using the 123 I-IMP microsphere model, we reported that the accuracy of determination of the integrated value of the input function from one-point arterial blood sampling can be increased by performing correction using the 5 min: 29 min ratio for the whole-brain count. However, failure to carry out the arterial blood collection at exactly 5 minutes after 123 I-IMP injection causes errors with this method, and there is thus a time limitation. We have now revised out method so that the one-point arterial blood sampling can be performed at any time during the interval between 5 minutes and 20 minutes after 123 I-IMP injection, with addition of a correction step for the sampling time. This revised method permits more accurate estimation of the integral of the input functions. This method was then applied to 174 experimental subjects: one-point blood samples collected at random times between 5 and 20 minutes, and the estimated values for the continuous arterial octanol extraction count (COC) were determined. The mean error rate between the COC and the actual measured continuous arterial octanol extraction count (OC) was 3.6%, and the standard deviation was 12.7%. Accordingly, in 70% of the cases, the rCBF was able to be estimated within an error rate of 13%, while estimation was possible in 95% of the cases within an error rate of 25%. This improved method is a simple technique for determination of the rCBF by 123 I-IMP microsphere model and one-point arterial blood sampling which no longer shows a time limitation and does not require any octanol extraction step. (author)

Restraint stress enhances arterial thrombosis in vivo--role of the sympathetic nervous system.

Science.gov (United States)

Stämpfli, Simon F; Camici, Giovanni G; Keller, Stephan; Rozenberg, Izabela; Arras, Margarete; Schuler, Beat; Gassmann, Max; Garcia, Irene; Lüscher, Thomas F; Tanner, Felix C

2014-01-01

Stress is known to correlate with the incidence of acute myocardial infarction. However, the molecular mechanisms underlying this correlation are not known. This study was designed to assess the effect of experimental stress on arterial thrombus formation, the key event in acute myocardial infarction. Mice exposed to 20 h of restraint stress displayed an increased arterial prothrombotic potential as assessed by photochemical injury-induced time to thrombotic occlusion. This increase was prevented by chemical sympathectomy performed through 6-hydroxydopamine (6-OHDA). Blood-born tissue factor (TF) activity was enhanced by stress and this increase could be prevented by 6-OHDA treatment. Vessel wall TF, platelet count, platelet aggregation, coagulation times (PT, aPTT), fibrinolytic system (t-PA and PAI-1) and tail bleeding time remained unaltered. Telemetric analysis revealed only minor hemodynamic changes throughout the stress protocol. Plasma catecholamines remained unaffected after restraint stress. Tumor necrosis factor alpha (TNF-α) plasma levels were unchanged and inhibition of TNF-α had no effect on stress-enhanced thrombosis. These results indicate that restraint stress enhances arterial thrombosis via the sympathetic nervous system. Blood-borne TF contributes, at least in part, to the observed effect whereas vessel wall TF, platelets, circulating coagulation factors, fibrinolysis and inflammation do not appear to play a role. These findings shed new light on the understanding of stress-induced cardiovascular events.

Timing of Incident Stroke Risk After Cervical Artery Dissection Presenting Without Ischemia.

Science.gov (United States)

Morris, Nicholas A; Merkler, Alexander E; Gialdini, Gino; Kamel, Hooman

2017-03-01

Cervical artery dissection is a common cause of stroke in young people. The temporal profile of stroke risk after cervical artery dissection presenting without ischemia remains uncertain. We performed a crossover cohort study using administrative claims data on all emergency department visits and acute care hospitalizations from 2005 to 2011 in CA, 2006 to 2013 in NY, and 2005 to 2013 in FL. Using previously validated International Classification of Diseases, Ninth Revision, Clinical Modification codes, we identified patients with a cervical artery dissection and no previous or concurrent stroke or transient ischemic attack diagnosis. We compared the risk of stroke in successive 2-week periods during the 12 weeks after dissection versus the corresponding 2-week period 1 year later. Absolute risk increases were calculated using McNemar test for matched data. In a sensitivity analysis, we limited our population to patients presenting with typical symptoms of cervical artery dissection. We identified 2791 patients with dissection without ischemia. The absolute increase in stroke risk was 1.25% (95% confidence interval, 0.84-1.67%) in the first 2 weeks after dissection compared with the same time period 1 year later. The absolute risk increase was 0.18% (95% confidence interval, 0.02-0.34%) during weeks 3 to 4 and was no longer significant during the remainder of the 12-week postdissection period. Our findings were similar in a sensitivity analysis identifying patients who presented with typical symptoms of acute dissection. The risk of stroke after cervical artery dissection unaccompanied by ischemia at time of diagnosis seems to be limited to the first 2 weeks. © 2017 American Heart Association, Inc.

Absolute quantitative autoradiography of low concentrations of [125I]-labeled proteins in arterial tissue

International Nuclear Information System (INIS)

Schnitzer, J.J.; Morrel, E.M.; Colton, C.K.; Smith, K.A.; Stemerman, M.B.

1987-01-01

We developed a method for absolute quantitative autoradiographic measurement of very low concentrations of [ 125 I]-labeled proteins in arterial tissue using Kodak NTB-2 nuclear emulsion. A precise linear relationship between measured silver grain density and isotope concentration was obtained with uniformly labeled standard sources composed of epoxy-embedded gelatin containing glutaraldehyde-fixed [ 125 I]-albumin. For up to 308-day exposures of 1 micron-thick tissue sections, background grain densities ranged from about two to eight grains/1000 micron 2, and the technique was sensitive to as little as about one grain/1000 micron 2 above background, which correspond to a radioactivity concentration of about 2 x 10(4) cpm/ml. A detailed statistical analysis of variability was performed and the sum of all sources of variation quantified. The half distance for spatial resolution was 1.7 micron. Both visual and automated techniques were employed for quantitative grain density analysis. The method was illustrated by measurement of in vivo transmural [ 125 I]-low-density lipoprotein [( 125 I]-LDL) concentration profiles in de-endothelialized rabbit thoracic aortic wall

Myogenic activation and calcium sensitivity of cannulated rat mesenteric small arteries

NARCIS (Netherlands)

VanBavel, E.; Wesselman, J. P.; Spaan, J. A.

1998-01-01

Pressure-induced activation of vascular smooth muscle may involve electromechanical as well as nonelectromechanical coupling mechanisms. We compared calcium-tone relations of cannulated rat mesenteric small arteries during pressure-induced activation, depolarization (16 to 46 mmol/L K+), and

Primary observation of clinical curative effect of superselective uterine artery embolization for treatment of placenta increta

International Nuclear Information System (INIS)

Wang Changfu; Zhang Heping; Zhang Hongxia; Jin Haiying; Wang Binjie; He Xiang; Zhang Jie; Li Changbo

2008-01-01

Objective: To explore the curative effect on superselective uterine artery embolization for treatment of placenta increta. Methods: Pelvic arteriography was performed to confirm bleeding vessels. Then a 5 F Cobra catheter was inserted superselectively into uterine artery ipsilateral to bleeding, through which methotrexatum (MTX) and gelatin sponge were injected for embolization. After the procedure, bleeding, blood pressure, dischargement of placenta tissue, uterine recuperation, and plasma β-HCG were monitored. Results: Bleeding vessels were confirmed in all of the 5 cases of placenta increta. Uterine artery embolization was successful at sole procedure. The operation time was 25.0 to 60.0 min, with the mean time (37.4 ± 5.8) min. Vaginal bleeding stoped in 3.0 to 12.0 minutes after embolization and the mean time was (5.7 ± 2.4) min. Blood pressure returned to normal after operation and vital signs were stable. Placenta tissue discharged on the 5th day to the 4th week after embolization and the mean time was 17 d. The uterus recuperated and blood β-HCG recovered simutaneously. The menstruation and ovulation during follow-up returned to normal. Conclusion: Superselective uterine artery embolization for treatment of placenta increta has advantages such as short operation time, minimal invasion, definite curative effect and reservation of uterus, which is worthy in clinical application. (authors)

The Influence of Tissue Ischemia Time on RNA Integrity and Patient-Derived Xenografts (PDX) Engraftment Rate in a Non-Small Cell Lung Cancer (NSCLC) Biobank.

Science.gov (United States)

Guerrera, Francesco; Tabbò, Fabrizio; Bessone, Luca; Maletta, Francesca; Gaudiano, Marcello; Ercole, Elisabetta; Annaratone, Laura; Todaro, Maria; Boita, Monica; Filosso, Pier Luigi; Solidoro, Paolo; Delsedime, Luisa; Oliaro, Alberto; Sapino, Anna; Ruffini, Enrico; Inghirami, Giorgio

2016-01-01

Bio-repositories are invaluable resources to implement translational cancer research and clinical programs. They represent one of the most powerful tools for biomolecular studies of clinically annotated cohorts, but high quality samples are required to generate reliable molecular readouts and functional studies. The objective of our study was to define the impact of cancer tissue ischemia time on RNA and DNA quality, and for the generation of Patient-Derived Xenografts (PDXs). One-hundred thirty-five lung cancer specimens were selected among our Institutional BioBank samples. Associations between different warm (surgical) and cold (ex-vivo) ischemia time ranges and RNA quality or PDXs engraftment rates were assessed. RNA quality was determined by RNA integrity number (RINs) values. Fresh viable tissue fragments were implanted subcutaneously in NSG mice and serially transplanted. RNAs with a RIN>7 were detected in 51% of the sample (70/135), with values of RIN significantly lower (OR 0.08, P = 0.01) in samples preserved for more than 3 hours before cryopreservation. Higher quality DNA samples had a concomitant high RIN. Sixty-three primary tumors (41 adenocarcinoma) were implanted with an overall engraftment rate of 33%. Both prolonged warm (>2 hours) and ex-vivo ischemia time (>10 hours) were associated to a lower engraftment rate (OR 0.09 P = 0.01 and OR 0.04 P = 0.008, respectively). RNA quality and PDXs engraftment rate were adversely affected by prolonged ischemia times. Proper tissue collection and processing reduce failure rate. Overall, NSCLC BioBanking represents an innovative modality, which can be successfully executed in routine clinical settings, when stringent Standard Operating Procedures are adopted.

Hippocampal “Time Cells”: Time versus Path Integration

Science.gov (United States)

Kraus, Benjamin J.; Robinson, Robert J.; White, John A.; Eichenbaum, Howard; Hasselmo, Michael E.

2014-01-01

SUMMARY Recent studies have reported the existence of hippocampal “time cells,” neurons that fire at particular moments during periods when behavior and location are relatively constant. However, an alternative explanation of apparent time coding is that hippocampal neurons “path integrate” to encode the distance an animal has traveled. Here, we examined hippocampal neuronal firing patterns as rats ran in place on a treadmill, thus “clamping” behavior and location, while we varied the treadmill speed to distinguish time elapsed from distance traveled. Hippocampal neurons were strongly influenced by time and distance, and less so by minor variations in location. Furthermore, the activity of different neurons reflected integration over time and distance to varying extents, with most neurons strongly influenced by both factors and some significantly influenced by only time or distance. Thus, hippocampal neuronal networks captured both the organization of time and distance in a situation where these dimensions dominated an ongoing experience. PMID:23707613

The flavonoid fisetin attenuates postischemic immune cell infiltration, activation and infarct size after transient cerebral middle artery occlusion in mice

Science.gov (United States)

Gelderblom, Mathias; Leypoldt, Frank; Lewerenz, Jan; Birkenmayer, Gabriel; Orozco, Denise; Ludewig, Peter; Thundyil, John; Arumugam, Thiruma V; Gerloff, Christian; Tolosa, Eva; Maher, Pamela; Magnus, Tim

2012-01-01

The development of the brain tissue damage in ischemic stroke is composed of an immediate component followed by an inflammatory response with secondary tissue damage after reperfusion. Fisetin, a flavonoid, has multiple biological effects, including neuroprotective and antiinflammatory properties. We analyzed the effects of fisetin on infarct size and the inflammatory response in a mouse model of stroke, temporary middle cerebral artery occlusion, and on the activation of immune cells, murine primary and N9 microglial and Raw264.7 macrophage cells and human macrophages, in an in vitro model of inflammatory immune cell activation by lipopolysaccharide (LPS). Fisetin not only protected brain tissue against ischemic reperfusion injury when given before ischemia but also when applied 3 hours after ischemia. Fisetin also prominently inhibited the infiltration of macrophages and dendritic cells into the ischemic hemisphere and suppressed the intracerebral immune cell activation as measured by intracellular tumor necrosis factor α (TNFα) production. Fisetin also inhibited LPS-induced TNFα production and neurotoxicity of macrophages and microglia in vitro by suppressing nuclear factor κB activation and JNK/Jun phosphorylation. Our findings strongly suggest that the fisetin-mediated inhibition of the inflammatory response after stroke is part of the mechanism through which fisetin is neuroprotective in cerebral ischemia. PMID:22234339

Time-dependent effect of orchidectomy on vascular nitric oxide and thromboxane A2 release. Functional implications to control cell proliferation through activation of the epidermal growth factor receptor.

Directory of Open Access Journals (Sweden)

Marta del Campo

Full Text Available This study analyzes whether the release of nitric oxide (NO and thromboxane A2 (TXA2 depends on the time lapsed since gonadal function is lost, and their correlation with the proliferation of vascular smooth muscle cells (VSMC mediated by the epidermal growth factor receptor (EGFR. For this purpose, aortic and mesenteric artery segments from control and 6-weeks or 5-months orchidectomized rats were used to measure NO and TXA2 release. The results showed that the basal and acetylcholine (ACh-induced NO release were decreased 6 weeks post-orchidectomy both in aorta and mesenteric artery, but were recovered 5 months thereafter up to levels similar to those found in arteries from control rats. The basal and ACh-induced TXA2 release increased in aorta and mesenteric artery 6 weeks post-orchidectomy, and was maintained at high levels 5 months thereafter. Since we previously observed that orchidectomy, which decreased testosterone level, enlarged the muscular layer of mesenteric arteries, the effect of testosterone on VSMC proliferation was analyzed. The results showed that treatment of cultured VSMC with testosterone downregulated mitogenic signaling pathways initiated by the ligand-dependent activation of the EGFR. In contrast, the EGFR pathways were constitutively active in mesenteric arteries of long-term orchidectomized rats. Thus, the exposure of mesenteric arteries from control rats to epidermal growth factor (EGF induced the activation of EGFR signaling pathways. However, the addition of EGF to arteries from orchidectomized rats failed to induce a further activation of these pathways. In conclusion, this study shows that the release of NO depends on the time lapsed since the gonadal function is lost, while the release of TXA2 is already increased after short periods post-orchidectomy. The alterations in these signaling molecules could contribute to the constitutive activation of the EGFR and its downstream signaling pathways after long period

Endovascular Management of Central Retinal Arterial Occlusion.

Science.gov (United States)

Agarwal, Nitin; Gala, Nihar B; Baumrind, Benjamin; Hansberry, David R; Thabet, Ahmad M; Gandhi, Chirag D; Prestigiacomo, Charles J

2016-11-01

Central retinal artery occlusion (CRAO) is an ophthalmologic emergency due to the sudden cessation of circulation to the inner retinal layer. Without immediate treatment, permanent blindness may ensue. Several treatment options exist, ranging from noninvasive medical management to thrombolysis. Nonetheless, ongoing debate exists regarding the best therapeutic strategy. The authors present the case of a 78-year-old woman with a medical history of hypercholesterolemia and rheumatoid arthritis who experienced complete loss of vision in her left eye. Following ophthalmologic evaluation demonstrating left CRAO, anterior chamber paracentesis was performed. Endovascular intervention was performed via local intra-arterial fibrinolysis with alteplase. Her vision returned to 20/20 following the procedure. In general, conventional therapies have not significantly improved patient outcomes. Several management options exist for CRAO. In general, conservative measures have not been reported to yield better patient outcomes as compared to the natural history of this medical emergency. Endovascular approaches are another option as observed with this case reported. In cases of CRAO, therapeutic strategies such as intra-arterial fibrinolysis utilize a local infusion of reactive tissue plasminogen activator directly at the site of occlusion via catheterization of the ophthalmic artery. Although several case series do show promising results after treating CRAO with intra-arterial fibrinolysis, further studies are required given the reports of complications.

Baroreflex and neurovascular responses to skeletal muscle mechanoreflex activation in humans: an exercise in integrative physiology.

Science.gov (United States)

Drew, Rachel C

2017-12-01

Cardiovascular adjustments to exercise resulting in increased blood pressure (BP) and heart rate (HR) occur in response to activation of several neural mechanisms: the exercise pressor reflex, central command, and the arterial baroreflex. Neural inputs from these feedback and feedforward mechanisms integrate in the cardiovascular control centers in the brain stem and modulate sympathetic and parasympathetic neural outflow, resulting in the increased BP and HR observed during exercise. Another specific consequence of the central neural integration of these inputs during exercise is increased sympathetic neural outflow directed to the kidneys, causing renal vasoconstriction, a key reflex mechanism involved in blood flow redistribution during increased skeletal muscle work. Studies in humans have shown that muscle mechanoreflex activation inhibits cardiac vagal outflow, decreasing the sensitivity of baroreflex control of HR. Metabolite sensitization of muscle mechanoreceptors can lead to reduced sensitivity of baroreflex control of HR, with thromboxane being one of the metabolites involved, via greater inhibition of cardiac vagal outflow without affecting baroreflex control of BP or baroreflex resetting. Muscle mechanoreflex activation appears to play a predominant role in causing renal vasoconstriction, both in isolation and in the presence of local metabolites. Limited investigations in older adults and patients with cardiovascular-related disease have provided some insight into how the influence of muscle mechanoreflex activation on baroreflex function and renal vasoconstriction is altered in these populations. However, future research is warranted to better elucidate the specific effect of muscle mechanoreflex activation on baroreflex and neurovascular responses with aging and cardiovascular-related disease. Copyright © 2017 the American Physiological Society.

Cardiovascular risk factors and collateral artery formation.

Science.gov (United States)

de Groot, D; Pasterkamp, G; Hoefer, I E

2009-12-01

Arterial lumen narrowing and vascular occlusion is the actual cause of morbidity and mortality in atherosclerotic disease. Collateral artery formation (arteriogenesis) refers to an active remodelling of non-functional vascular anastomoses to functional collateral arteries, capable to bypass the site of obstruction and preserve the tissue that is jeopardized by ischaemia. Hemodynamic forces such as shear stress and wall stress play a pivotal role in collateral artery formation, accompanied by the expression of various cytokines and invasion of circulating leucocytes. Arteriogenesis hence represents an important compensatory mechanism for atherosclerotic vessel occlusion. As arteriogenesis mostly occurs when lumen narrowing by atherosclerotic plaques takes place, presence of cardiovascular risk factors (e.g. hypertension, hypercholesterolaemia and diabetes) is highly likely. Risk factors for atherosclerotic disease affect collateral artery growth directly and indirectly by altering hemodynamic forces or influencing cellular function and proliferation. Adequate collateralization varies significantly among atherosclerotic patients, some profit from the presence of extensive collateral networks, whereas others do not. Cardiovascular risk factors could increase the risk of adverse cardiovascular events in certain patients because of the reduced protection through an alternative vascular network. Likewise, drugs primarily thought to control cardiovascular risk factors might contribute or counteract collateral artery growth. This review summarizes current knowledge on the influence of cardiovascular risk factors and the effects of cardiovascular medication on the development of collateral vessels in experimental and clinical studies.

Intrinsic regulation of blood flow in adipose tissue

DEFF Research Database (Denmark)

Henriksen, O; Nielsen, Steen Levin; Paaske, W

1976-01-01

Previous studies on intact human subcutaneous tissue have shown, that blood flow remains constant during minor changes in perfusion pressure. This so-called autoregulatory response has not been demonstrable in isolated preparations of adipose tissue. In the present study on isolated, denervated...... subcutaneous tissue in female rabbits only 2 of 12 expts. revealed an autoregulatory response during reduction in arterial perfusion pressure. Effluent blood flow from the tissue in the control state was 15.5 ml/100 g-min (S.D. 6.4, n = 12) corresponding to slight vasodilatation of the exposed tissue...... vasoconstriction with pronounced flow reduction. These two reactions may be important for local regulation of blood flow in subcutaneous tissue during orthostatic changes in arterial and venous pressure. It is concluded that the response in adipose tissue to changes in arterial pressure (autoregulation), venous...

Evaluation of arterial embolization therapy of hepatocellular carcinoma by computed tomography

Energy Technology Data Exchange (ETDEWEB)

Ohishi, H; Ohue, S; Ide, K [Nara Medical Univ., Kashihara (Japan)

1981-11-01

The therapeutic effect of arterial embolization performed to 18 patients with hepatocellular carcinoma was evaluated by means of computed tomography (CT). 1) After embolization, the tumor was observed to have been reduced in size in all the cases. The relative attenuation coefficients of the tumor region to surrounding liver tissue was decreased at initial stage after arterial embolization, however, it showed a tendency of more elevation than the initial stage in the cases performed follow-up CT. The decrease of the attenuation values at the initial stage suggests the ischemic necrosis, while its elevation is considered attributable to subsequent histologic change and tumor shrinkage. 2) The follow-up CT examination after the arterial embolization on hepatocellular carcinoma provides significant facility for evaluation of its effectiveness and judgement of the time for the repeat arterial embolization.

Tissue integration in oral and maxillo-facial reconstruction

International Nuclear Information System (INIS)

Van Steenberghe, D.

1986-01-01

These proceedings on tissue-integrated prostheses in the rehabilitation of the head and neck area cover both basic scientific and clinical aspects in intra- as well as extra-oral applications. Also the discussions and conclusions of the 'State-of-the-Art' meeting are included. (Auth.)

Effect of preoperative oral S-1 combined with regional intra-arterial chemotherapy on malignant molecule expression in locally advanced unresectable gastric cancer tissue

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Lei Liu

2016-11-01

Full Text Available Objective: To study the effect of preoperative oral S-1 combined with regional intra-arterial chemotherapy on malignant molecule expression in locally advanced unresectable gastric cancer tissue. Methods: A total of 144 patients with locally advanced gastric cancer receiving surgical resection after neoadjuvant chemotherapy in our hospital between May 2012 and August 2015 were selected and randomly divided into experimental group who received preoperative oral S-1 combined with regional intra-arterial chemotherapy and control group who received preoperative intravenous systemic chemotherapy. The levels of serum tumor markers were determined after chemotherapy, and the expression levels of tumor suppressor genes and cell cycle-related molecules in tumor tissue were determined after surgical resection. Results: After neoadjuvant chemotherapy, the serum G-17, TK-1, CEA, CA19-9, CA12-5, CA72-4 and CK, CK-MB, ALT, AST levels of experimental group were significantly lower than those of control group; after surgical resection, the p16, p27, PTEN and TXNIP mRNA levels in tumor tissue of experimental group were significantly higher than those of control group while CyclinB2, CyclinD1, CyclinE, CDK1 and CDK2 mRNA levels were significantly lower than those of control group. Conclusions: Preoperative oral S-1 combined with regional intra-arterial chemotherapy can more effectively kill gastric cancer cells, reduce tumor load, inhibit cell cycle and promote cell apoptosis.

Activation of the Arterial Program Drives Development of Definitive Hemogenic Endothelium with Lymphoid Potential

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Mi Ae Park

2018-05-01

Full Text Available Summary: Understanding the pathways guiding the development of definitive hematopoiesis with lymphoid potential is essential for advancing human pluripotent stem cell (hPSC technologies for the treatment of blood diseases and immunotherapies. In the embryo, lymphoid progenitors and hematopoietic stem cells (HSCs arise from hemogenic endothelium (HE lining arteries but not veins. Here, we show that activation of the arterial program through ETS1 overexpression or by modulating MAPK/ERK signaling pathways at the mesodermal stage of development dramatically enhanced the formation of arterial-type HE expressing DLL4 and CXCR4. Blood cells generated from arterial HE were more than 100-fold enriched in T cell precursor frequency and possessed the capacity to produce B lymphocytes and red blood cells expressing high levels of BCL11a and β-globin. Together, these findings provide an innovative strategy to aid in the generation of definitive lymphomyeloid progenitors and lymphoid cells from hPSCs for immunotherapy through enhancing arterial programming of HE. : Park et al. find that activation of the arterial program through ETS1 overexpression or by modulating MAPK/ERK signaling pathways at the mesodermal stage of development dramatically enhances formation of arterial-type hemogenic endothelium (HE from hPSCs. Blood cells generated from arterial HE are highly enriched in definitive lymphomyeloid progenitors. Keywords: human pluripotent stem cells, hemogenic endothelium, T cells, hematopoietic stem cells, hematopoiesis, ETS1, MAPK/ERK signaling

Arterial Transit Time-corrected Renal Blood Flow Measurement with Pulsed Continuous Arterial Spin Labeling MR Imaging.

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Shimizu, Kazuhiro; Kosaka, Nobuyuki; Fujiwara, Yasuhiro; Matsuda, Tsuyoshi; Yamamoto, Tatsuya; Tsuchida, Tatsuro; Tsuchiyama, Katsuki; Oyama, Nobuyuki; Kimura, Hirohiko

2017-01-10

The importance of arterial transit time (ATT) correction for arterial spin labeling MRI has been well debated in neuroimaging, but it has not been well evaluated in renal imaging. The purpose of this study was to evaluate the feasibility of pulsed continuous arterial spin labeling (pcASL) MRI with multiple post-labeling delay (PLD) acquisition for measuring ATT-corrected renal blood flow (ATC-RBF). A total of 14 volunteers were categorized into younger (n = 8; mean age, 27.0 years) and older groups (n = 6; 64.8 years). Images of pcASL were obtained at three different PLDs (0.5, 1.0, and 1.5 s), and ATC-RBF and ATT were calculated using a single-compartment model. To validate ATC-RBF, a comparative study of effective renal plasma flow (ERPF) measured by 99m Tc-MAG3 scintigraphy was performed. ATC-RBF was corrected by kidney volume (ATC-cRBF) for comparison with ERPF. The younger group showed significantly higher ATC-RBF (157.68 ± 38.37 mL/min/100 g) and shorter ATT (961.33 ± 260.87 ms) than the older group (117.42 ± 24.03 mL/min/100 g and 1227.94 ± 226.51 ms, respectively; P renal ASL-MRI as debated in brain imaging.

Biosensor cell assay for measuring real-time aldosterone-induced release of histamine from mesenteric arteries

DEFF Research Database (Denmark)

Dalgaard, Emil G; Andersen, Kenneth; Svenningsen, Per

2017-01-01

as a sensitive biosensor assay for histamine release from isolated mouse mesenteric arteries. Activation of the H1 receptor by histamine was measured as an increased number of intracellular Ca(2+) transient peaks using fluorescence imaging RESULTS: The developed biosensor was sensitive to histamine...... in physiological relevant concentrations and responded to substances released by the artery preparation. Aldosterone treatment of mesenteric arteries from wild type mice for 50 minutes resulted in an increased number of intracellular Ca(2+) transient peaks in the biosensor cells, which was significantly inhibited...... by the histamine H1 blocker pyrilamine. Mesenteric arteries from mast cell deficient SASH mice induced similar pyrilamine-sensitive Ca(2+) transient response in the biosensor cells. Mesenteric arteries from wild type and SASH mice expressed histamine decarboxylase mRNA, indicating that mast cells are not the only...

Energetic and spatial constraints of arterial networks

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Sandro Rossitti

1995-06-01

Full Text Available The principle of minimum work (PMW is a parametric optimization model for the growth and adaptation of arterial trees. A balance between energy dissipation due to frictional resistance of laminar flow (shear stress and the minimum volume of the blood and vessel wall tissue is achieved when the vessel radii are adjusted to the cube root of the volumetric flow. The PMW is known to apply over several magnitudes of vessel calibers, and in many different organs, including the brain, in humans and in animals. Animal studies suggest that blood flow in arteries is approximately proportional to the cube of the vessel radius, and that arteries alter their caliber in response to sustained changes of blood flow according to PMW. Remodelling of the retinal arteriolar network to long-term changes in blood flow was observed in humans. Remodelling of whole arterial networks occurs in the form of increase or diminishing of vessel calibers. Shear stress induced endothelial mediation seems to be the regulating mechanism for the maintenance of this optimum blood flow/vessel diameter relation. Arterial trees are also expected to be nearly space filing. The vascular system is constructed in such a way that, while blood vessels occupy only a small percentage of the body volume leaving the bulk to tissue, they also crisscross organs so tightly that every point in the tissue lies on the boundary between an artery and a vein. This review describes how the energetic optimum principle for least energy cost for blood flow is also compatible with the spatial constraints of arterial networks according to concepts derived from fractal geometry.

Characterization of HBV integration patterns and timing in liver cancer and HBV-infected livers.

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Furuta, Mayuko; Tanaka, Hiroko; Shiraishi, Yuichi; Unida, Takuro; Imamura, Michio; Fujimoto, Akihiro; Fujita, Masahi; Sasaki-Oku, Aya; Maejima, Kazuhiro; Nakano, Kaoru; Kawakami, Yoshiiku; Arihiro, Koji; Aikata, Hiroshi; Ueno, Masaki; Hayami, Shinya; Ariizumi, Shun-Ichi; Yamamoto, Masakazu; Gotoh, Kunihito; Ohdan, Hideki; Yamaue, Hiroki; Miyano, Satoru; Chayama, Kazuaki; Nakagawa, Hidewaki

2018-05-18

Integration of Hepatitis B virus (HBV) into the human genome can cause genetic instability, leading to selective advantages for HBV-induced liver cancer. Despite the large number of studies for HBV integration into liver cancer, little is known about the mechanism of initial HBV integration events owing to the limitations of materials and detection methods. We conducted an HBV sequence capture, followed by ultra-deep sequencing, to screen for HBV integrations in 111 liver samples from human-hepatocyte chimeric mice with HBV infection and human clinical samples containing 42 paired samples from non-tumorous and tumorous liver tissues. The HBV infection model using chimeric mice verified the efficiency of our HBV-capture analysis and demonstrated that HBV integration could occur 23 to 49 days after HBV infection via microhomology-mediated end joining and predominantly in mitochondrial DNA. Overall HBV integration sites in clinical samples were significantly enriched in regions annotated as exhibiting open chromatin, a high level of gene expression, and early replication timing in liver cells. These data indicate that HBV integration in liver tissue was biased according to chromatin accessibility, with additional selection pressures in the gene promoters of tumor samples. Moreover, an integrative analysis using paired non-tumorous and tumorous samples and HBV-related transcriptional change revealed the involvement of TERT and MLL4 in clonal selection. We also found frequent and non-tumorous liver-specific HBV integrations in FN1 and HBV-FN1 fusion transcript. Extensive survey of HBV integrations facilitates and improves the understanding of the timing and biology of HBV integration during infection and HBV-related hepatocarcinogenesis.

A novel method to determine perineal artery occlusion among male bicyclists.

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Parthiban, Sujeeth; Hotaling, James M; Kathrins, Martin; Baftiri, Amit P; Freels, Sally; Niederberger, Craig S

2015-01-01

Background. Perineal pressure due to bicycle riding has been associated with erectile dysfunction. We developed a novel method to measure the occlusive force exerted over the perineal arteries and determined perineal artery occlusion by a variety of seat designs. Methods. Doppler ultrasonography facilitated perineal artery localization and determination of the force required for perineal artery occlusion in 20 healthy men. Flexiforce(®) sensors were affixed over the proximal and distal aspects of the perineal arteries bilaterally. Individuals completed bicycle rides in the road- and stationary-settings with six distinct seat designs, including those with and without an anterior "nose." Results. The occlusion time proportion of the total ride time was calculated for each trial. The overall occlusion time proportion was 0.59 (95% CI [0.45-0.73]) across all seats and settings. The "no-nose" bicycle seat and the stationary-setting demonstrated significantly lower occlusion proportion times than the traditional nose bicycle seat and road-setting, respectively. However, all bicycle seats yielded an occlusion time proportion of 0.41 or greater. Discussion. Our method of real-time, non-invasive force measurement localized to the perineal arteries may be used to validate future bicycle seat design. It also underscores the significant risk of perineal artery insufficiency in men who are avid bicyclists. This risk may be minimized by using newer "no-nose" bicycle seats.

Visit-to-Visit Blood Pressure Variability in Young Adulthood and Hippocampal Volume and Integrity at Middle Age: The CARDIA Study (Coronary Artery Risk Development in Young Adults).

Science.gov (United States)

Yano, Yuichiro; Reis, Jared P; Levine, Deborah A; Bryan, R Nick; Viera, Anthony J; Shimbo, Daichi; Tedla, Yacob G; Allen, Norrina B; Schreiner, Pamela J; Bancks, Michael P; Sidney, Stephen; Pletcher, Mark J; Liu, Kiang; Greenland, Philip; Lloyd-Jones, Donald M; Launer, Lenore J

2017-12-01

The aims of this study are to assess the relationships of visit-to-visit blood pressure (BP) variability in young adulthood to hippocampal volume and integrity at middle age. We used data over 8 examinations spanning 25 years collected in the CARDIA study (Coronary Artery Risk Development in Young Adults) of black and white adults (age, 18-30 years) started in 1985 to 1986. Visit-to-visit BP variability was defined as by SD BP and average real variability (ARV BP , defined as the absolute differences of BP between successive BP measurements). Hippocampal tissue volume standardized by intracranial volume (%) and integrity assessed by fractional anisotropy were measured by 3-Tesla magnetic resonance imaging at the year-25 examination (n=545; mean age, 51 years; 54% women and 34% African Americans). Mean systolic BP (SBP)/diastolic BP levels were 110/69 mm Hg at year 0 (baseline), 117/73 mm Hg at year 25, and ARV SBP and SD SBP were 7.7 and 7.9 mm Hg, respectively. In multivariable-adjusted linear models, higher ARV SBP was associated with lower hippocampal volume (unstandardized regression coefficient [standard error] with 1-SD higher ARV SBP : -0.006 [0.003]), and higher SD SBP with lower hippocampal fractional anisotropy (-0.02 [0.01]; all P young adulthood may be useful in assessing the potential risk for reductions in hippocampal volume and integrity in midlife. © 2017 American Heart Association, Inc.

Benchmarking Telestroke Proficiency: Page-to-Needle Time Among Neurovascular Fellows and Attendings.

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Jagolino-Cole, Amanda L; Bozorgui, Shima; Ankrom, Christy M; Bambhroliya, Arvind B; Cossey, Tiffany D; Trevino, Alyssa D; Savitz, Sean I; Wu, Tzu-Ching; Vahidy, Farhaan S

2017-09-01

Formal telestroke training for neurovascular fellows (NVFs) is necessary because of growing use of telestroke technologies in the management of acute ischemic stroke; yet, educational approaches and training benchmarks are not formalized. Time between telestroke consultant page and tissue-type plasminogen activator administration (page-to-needle time, PTNT) can provide an objective measure of proficiency. We compared PTNT between NVFs and neurovascular attendings (NVAs) and evaluated changes in PTNT with experience. We identified suspected acute ischemic stroke patients in our telestroke registry from July 2013 to December 2015 who received tissue-type plasminogen activator. Using multivariable quantile regression, we estimated the difference and 95% confidence interval in median PTNT between NVFs and NVAs. We also report the coefficient of change in PTNT over increasing number of telestroke consults. NVFs evaluated 53.7% of 618 tissue-type plasminogen activator cases over telestroke. NVAs had significantly shorter PTNT compared with NVFs, with a difference in median PTNT of -9 minutes (95% confidence interval, -12.3 to -5.7). This difference persisted when adjusted for relative tissue-type plasminogen activator contraindications. For each additional telestroke consult, PTNT decreased by 0.07 minutes for NVFs or NVAs ( P =0.02 and importance of integrating telestroke training into supervised neurovascular fellowships to increase proficiency prior to independent practice and suggest that PTNT can be a benchmark for tracking proficiency. © 2017 American Heart Association, Inc.

[Evaluation and Optimization of Microvascular Arterial Anastomoses by Transit Time Flow Measurement].

Science.gov (United States)

Herberhold, S; Röttker, J; Bartmann, D; Solbach, A; Keiner, S; Welz, A; Bootz, F; Laffers, W

2016-03-01

INDRODUCTION: The regular application of transit time flow measurement in microvascular anastomoses during heart surgery has lead to improvements of the outcome of coronary artery bypass grafts. Our study was meant to discover whether this measurement method was also applicable for evaluation and optimization of microvascular arterial anastomoses of radial forearm flaps. In this prospective examination a combining ultrasound imaging and transit time flow measurement device (VeriQ, MediStim) was used during surgery to assess anastomotic quality of 15 radial forearm flaps. Pulsatility index (PI) and mean blood flow were measured immediately after opening the arterial anastomosis as well as 15 min afterwards. Furthermore, application time and description of handling were recorded seperately for every assessment. Mean blood flow immediately after opening the anastomosis and 15 min later were 3.9 and 3.4 ml/min resepectively showing no statistically significant difference (p=0.96). There was no significance in the increase of pulsatility index from 22.1 to 27.2 (p=0.09) during the same time range, either. Due to measurement results showing atypical pulse curves in 2 cases decision for surgical revision of the anastomoses was made. All forearm flaps showed good vascularisation during follow-up. Time for device set up, probe placement and measurements was about 20 min. Handling was described to be uncomplicated without exception. There were no noteworthy problems. Transit time flow measurement contributes to the improvement of anastomotic quality and therefore to the overall outcome of radial forearm flaps. The examined measurement method provides objective results and is useful for documentation purposes. © Georg Thieme Verlag KG Stuttgart · New York.

Connective tissue-activating peptide III: a novel blood biomarker for early lung cancer detection.

Science.gov (United States)

Yee, John; Sadar, Marianne D; Sin, Don D; Kuzyk, Michael; Xing, Li; Kondra, Jennifer; McWilliams, Annette; Man, S F Paul; Lam, Stephen

2009-06-10

There are no reliable blood biomarkers to detect early lung cancer. We used a novel strategy that allows discovery of differentially present proteins against a complex and variable background. Mass spectrometry analyses of paired pulmonary venous-radial arterial blood from 16 lung cancer patients were applied to identify plasma proteins potentially derived from the tumor microenvironment. Two differentially expressed proteins were confirmed in 64 paired venous-arterial blood samples using an immunoassay. Twenty-eight pre- and postsurgical resection peripheral blood samples and two independent, blinded sets of plasma from 149 participants in a lung cancer screening study (49 lung cancers and 100 controls) and 266 participants from the National Heart Lung and Blood Institute Lung Health Study (45 lung cancer and 221 matched controls) determined the accuracy of the two protein markers to detect subclinical lung cancer. Connective tissue-activating peptide III (CTAP III)/ neutrophil activating protein-2 (NAP-2) and haptoglobin were identified to be significantly higher in venous than in arterial blood. CTAP III/NAP-2 levels decreased after tumor resection (P = .01). In two independent population cohorts, CTAP III/NAP-2 was significantly associated with lung cancer and improved the accuracy of a lung cancer risk prediction model that included age, smoking, lung function (FEV(1)), and an interaction term between FEV(1) and CTAP III/NAP-2 (area under the curve, 0.84; 95% CI, 0.77 to 0.91) compared to CAPIII/NAP-2 alone. We identified CTAP III/NAP-2 as a novel biomarker to detect preclinical lung cancer. The study underscores the importance of applying blood biomarkers as part of a multimodal lung cancer risk prediction model instead of as stand-alone tests.

Three-dimensional bioprinting of thick vascularized tissues

Science.gov (United States)

Kolesky, David B.; Homan, Kimberly A.; Skylar-Scott, Mark A.; Lewis, Jennifer A.

2016-03-01

The advancement of tissue and, ultimately, organ engineering requires the ability to pattern human tissues composed of cells, extracellular matrix, and vasculature with controlled microenvironments that can be sustained over prolonged time periods. To date, bioprinting methods have yielded thin tissues that only survive for short durations. To improve their physiological relevance, we report a method for bioprinting 3D cell-laden, vascularized tissues that exceed 1 cm in thickness and can be perfused on chip for long time periods (>6 wk). Specifically, we integrate parenchyma, stroma, and endothelium into a single thick tissue by coprinting multiple inks composed of human mesenchymal stem cells (hMSCs) and human neonatal dermal fibroblasts (hNDFs) within a customized extracellular matrix alongside embedded vasculature, which is subsequently lined with human umbilical vein endothelial cells (HUVECs). These thick vascularized tissues are actively perfused with growth factors to differentiate hMSCs toward an osteogenic lineage in situ. This longitudinal study of emergent biological phenomena in complex microenvironments represents a foundational step in human tissue generation.

Analysis of tracer transit in rat brain after carotid artery and femoral vein administrations using linear system theory.

Science.gov (United States)

Rudin, M; Beckmann, N; Sauter, A

1997-01-01

Determination of tissue perfusion rates by MRI bolus tracking methods relies on the central volume principle which states that tissue blood flow is given by the tissue blood volume divided by the mean tracer transit time (MTT). Accurate determination of the MTT requires knowledge of the arterial input function which in MRI experiments is usually not known, especially when using small animals. The problem of unknown arterial input can be circumvented in animal experiments by directly injecting the contrast agent into a feeding artery of the tissue of interest. In the present article the passage of magnetite nanoparticles through the rat cerebral cortex is analyzed after injection into the internal carotid artery. The results are discussed in the framework of linear system theory using a one-compartment model for brain tissue and by using the well characterized gamma-variate function to describe the tissue concentration profile of the contrast agent. The results obtained from the intra-arterial tracer administration experiments are then compared with the commonly used intra-venous injection of the contrast agent in order to estimate the contribution of the peripheral circulation to the MTT values in the latter case. The experiments were analyzed using a two-compartment model and the gamma-variate function. As an application perfusion rates in normal and ischemic cerebral cortex of hypertensive rats were estimated in a model of focal cerebral ischemia. The results indicate that peripheral circulation has a significant influence on the MTT values and thus on the perfusion rates, which cannot be neglected.

Cerebral perfusion characteristics show differences in younger versus older children with sickle cell anaemia: Results from a multiple-inflow-time arterial spin labelling study.

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Kawadler, Jamie M; Hales, Patrick W; Barker, Simon; Cox, Timothy C S; Kirkham, Fenella J; Clark, Chris A

2018-03-30

Sickle cell anaemia (SCA) is associated with chronic anaemia and oxygen desaturation, which elevate cerebral blood flow (CBF) and increase the risk of neurocognitive complications. Arterial spin labelling (ASL) provides a methodology for measuring CBF non-invasively; however, ASL techniques using only a single inflow time are not sufficient to fully characterize abnormal haemodynamic behaviour in SCA. This study investigated haemodynamic parameters from a multi-inflow-time ASL acquisition in younger (8-12 years) and older (13-18 years) children with SCA with and without silent cerebral infarction (SCI+/-) (n = 20 and 19 respectively, 6 and 4 SCI+ respectively) and healthy controls (n = 9 and 7 respectively). Compared with controls, CBF was elevated globally in both groups of patients. In the younger SCA patients, blood oxygen content was negatively correlated with CBF in the middle and posterior cerebral artery territories and significantly positively correlated with bolus arrival time (BAT) in the anterior and middle cerebral artery territories. In older children, SCA patients had significantly shorter BAT than healthy controls and there was a significant negative correlation between CBF and oxygen content only in the territory of the posterior cerebral artery, with a trend for a correlation in the anterior cerebral artery but no relationship for the middle cerebral artery territory. In the younger group, SCI+ patients had significantly higher CBF in the posterior cerebral artery territory (SCI+ mean = 92.78 ml/100 g/min; SCI- mean = 72.71 ml/100 g/min; F = 4.28, p = 0.04), but this no longer reached significance when two children with abnormal transcranial Doppler and one with haemoglobin SC disease were excluded, and there were no significant differences between patients with and without SCI in the older children. With age, there appears to be increasing disparity between patients and controls in terms of the relationship between CBF and oxygen

Modulation of macrophage activation state protects tissue from necrosis during critical limb ischemia in thrombospondin-1-deficient mice.

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Nicolas Bréchot

Full Text Available BACKGROUND: Macrophages, key regulators of healing/regeneration processes, strongly infiltrate ischemic tissues from patients suffering from critical limb ischemia (CLI. However pro-inflammatory markers correlate with disease progression and risk of amputation, suggesting that modulating macrophage activation state might be beneficial. We previously reported that thrombospondin-1 (TSP-1 is highly expressed in ischemic tissues during CLI in humans. TSP-1 is a matricellular protein that displays well-known angiostatic properties in cancer, and regulates inflammation in vivo and macrophages properties in vitro. We therefore sought to investigate its function in a mouse model of CLI. METHODS AND FINDINGS: Using a genetic model of tsp-1(-/- mice subjected to femoral artery excision, we report that tsp-1(-/- mice were clinically and histologically protected from necrosis compared to controls. Tissue protection was associated with increased postischemic angiogenesis and muscle regeneration. We next showed that macrophages present in ischemic tissues exhibited distinct phenotypes in tsp-1(-/- and wt mice. A strong reduction of necrotic myofibers phagocytosis was observed in tsp-1(-/- mice. We next demonstrated that phagocytosis of muscle cell debris is a potent pro-inflammatory signal for macrophages in vitro. Consistently with these findings, macrophages that infiltrated ischemic tissues exhibited a reduced postischemic pro-inflammatory activation state in tsp-1(-/- mice, characterized by a reduced Ly-6C expression and a less pro-inflammatory cytokine expression profile. Finally, we showed that monocyte depletion reversed clinical and histological protection from necrosis observed in tsp-1(-/- mice, thereby demonstrating that macrophages mediated tissue protection in these mice. CONCLUSION: This study defines targeting postischemic macrophage activation state as a new potential therapeutic approach to protect tissues from necrosis and promote tissue

Dll4-Notch signaling determines the formation of native arterial collateral networks and arterial function in mouse ischemia models.

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Cristofaro, Brunella; Shi, Yu; Faria, Marcella; Suchting, Steven; Leroyer, Aurelie S; Trindade, Alexandre; Duarte, Antonio; Zovein, Ann C; Iruela-Arispe, M Luisa; Nih, Lina R; Kubis, Nathalie; Henrion, Daniel; Loufrani, Laurent; Todiras, Mihail; Schleifenbaum, Johanna; Gollasch, Maik; Zhuang, Zhen W; Simons, Michael; Eichmann, Anne; le Noble, Ferdinand

2013-04-01

Arteriogenesis requires growth of pre-existing arteriolar collateral networks and determines clinical outcome in arterial occlusive diseases. Factors responsible for the development of arteriolar collateral networks are poorly understood. The Notch ligand Delta-like 4 (Dll4) promotes arterial differentiation and restricts vessel branching. We hypothesized that Dll4 may act as a genetic determinant of collateral arterial networks and functional recovery in stroke and hind limb ischemia models in mice. Genetic loss- and gain-of-function approaches in mice showed that Dll4-Notch signaling restricts pial collateral artery formation by modulating arterial branching morphogenesis during embryogenesis. Adult Dll4(+/-) mice showed increased pial collateral numbers, but stroke volume upon middle cerebral artery occlusion was not reduced compared with wild-type littermates. Likewise, Dll4(+/-) mice showed reduced blood flow conductance after femoral artery occlusion, and, despite markedly increased angiogenesis, tissue ischemia was more severe. In peripheral arteries, loss of Dll4 adversely affected excitation-contraction coupling in arterial smooth muscle in response to vasopressor agents and arterial vessel wall adaption in response to increases in blood flow, collectively contributing to reduced flow reserve. We conclude that Dll4-Notch signaling modulates native collateral formation by acting on vascular branching morphogenesis during embryogenesis. Dll4 furthermore affects tissue perfusion by acting on arterial function and structure. Loss of Dll4 stimulates collateral formation and angiogenesis, but in the context of ischemic diseases such beneficial effects are overruled by adverse functional changes, demonstrating that ischemic recovery is not solely determined by collateral number but rather by vessel functionality.

Dll4-Notch signaling determines the formation of native arterial collateral networks and arterial function in mouse ischemia models

Science.gov (United States)

Cristofaro, Brunella; Shi, Yu; Faria, Marcella; Suchting, Steven; Leroyer, Aurelie S.; Trindade, Alexandre; Duarte, Antonio; Zovein, Ann C.; Iruela-Arispe, M. Luisa; Nih, Lina R.; Kubis, Nathalie; Henrion, Daniel; Loufrani, Laurent; Todiras, Mihail; Schleifenbaum, Johanna; Gollasch, Maik; Zhuang, Zhen W.; Simons, Michael; Eichmann, Anne; le Noble, Ferdinand

2013-01-01

Arteriogenesis requires growth of pre-existing arteriolar collateral networks and determines clinical outcome in arterial occlusive diseases. Factors responsible for the development of arteriolar collateral networks are poorly understood. The Notch ligand Delta-like 4 (Dll4) promotes arterial differentiation and restricts vessel branching. We hypothesized that Dll4 may act as a genetic determinant of collateral arterial networks and functional recovery in stroke and hind limb ischemia models in mice. Genetic loss- and gain-of-function approaches in mice showed that Dll4-Notch signaling restricts pial collateral artery formation by modulating arterial branching morphogenesis during embryogenesis. Adult Dll4+/- mice showed increased pial collateral numbers, but stroke volume upon middle cerebral artery occlusion was not reduced compared with wild-type littermates. Likewise, Dll4+/- mice showed reduced blood flow conductance after femoral artery occlusion, and, despite markedly increased angiogenesis, tissue ischemia was more severe. In peripheral arteries, loss of Dll4 adversely affected excitation-contraction coupling in arterial smooth muscle in response to vasopressor agents and arterial vessel wall adaption in response to increases in blood flow, collectively contributing to reduced flow reserve. We conclude that Dll4-Notch signaling modulates native collateral formation by acting on vascular branching morphogenesis during embryogenesis. Dll4 furthermore affects tissue perfusion by acting on arterial function and structure. Loss of Dll4 stimulates collateral formation and angiogenesis, but in the context of ischemic diseases such beneficial effects are overruled by adverse functional changes, demonstrating that ischemic recovery is not solely determined by collateral number but rather by vessel functionality. PMID:23533173

Imaging arterial cells, atherosclerosis, and restenosis by multimodal nonlinear optical microscopy

Science.gov (United States)

Wang, Han-Wei; Simianu, Vlad; Locker, Matthew J.; Sturek, Michael; Cheng, Ji-Xin

2008-02-01

By integrating sum-frequency generation (SFG), and two-photon excitation fluorescence (TPEF) on a coherent anti-Stokes Raman scattering (CARS) microscope platform, multimodal nonlinear optical (NLO) imaging of arteries and atherosclerotic lesions was demonstrated. CARS signals arising from CH II-rich membranes allowed visualization of endothelial cells and smooth muscle cells in a carotid artery. Additionally, CARS microscopy allowed vibrational imaging of elastin and collagen fibrils which are rich in CH II bonds in their cross-linking residues. The extracellular matrix organization was further confirmed by TPEF signals arising from elastin's autofluorescence and SFG signals arising from collagen fibrils' non-centrosymmetric structure. The system is capable of identifying different atherosclerotic lesion stages with sub-cellular resolution. The stages of atherosclerosis, such as macrophage infiltration, lipid-laden foam cell accumulation, extracellular lipid distribution, fibrous tissue deposition, plaque establishment, and formation of other complicated lesions could be viewed by our multimodal CARS microscope. Collagen percentages in the region adjacent to coronary artery stents were resolved. High correlation between NLO and histology imaging evidenced the validity of the NLO imaging. The capability of imaging significant components of an arterial wall and distinctive stages of atherosclerosis in a label-free manner suggests the potential application of multimodal nonlinear optical microscopy to monitor the onset and progression of arterial diseases.

Noninvasive Real-Time Assessment of Cell Viability in a Three-Dimensional Tissue.

Science.gov (United States)

Mahfouzi, Seyed Hossein; Amoabediny, Ghassem; Doryab, Ali; Safiabadi-Tali, Seyed Hamid; Ghanei, Mostafa

2018-04-01

Maintaining cell viability within 3D tissue engineering scaffolds is an essential step toward a functional tissue or organ. Assessment of cell viability in 3D scaffolds is necessary to control and optimize tissue culture process. Monitoring systems based on respiration activity of cells (e.g., oxygen consumption) have been used in various cell cultures. In this research, an online monitoring system based on respiration activity was developed to monitor cell viability within acellular lung scaffolds. First, acellular lung scaffolds were recellularized with human umbilical cord vein endothelial cells, and then, cell viability was monitored during a 5-day period. The real-time monitoring system generated a cell growth profile representing invaluable information on cell viability and proliferative states during the culture period. The cell growth profile obtained by the monitoring system was consistent with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide analysis and glucose consumption measurement. This system provided a means for noninvasive, real-time, and repetitive investigation of cell viability. Also, we showed the applicability of this monitoring system by introducing shaking as an operating parameter in a long-term culture.

Coronary artery to left ventricle fistula

Directory of Open Access Journals (Sweden)

Kumar Vivek

2005-11-01

Full Text Available Abstract Background Coronary cameral fistulas are an uncommon entity, the etiology of which may be congenital or traumatic. They involve abnormal termination of a coronary artery, usually the right coronary, into a cardiac chamber, usually the right ventricle. Case Presentation We describe a case of female patient with severe aortic stenosis and interventricular septal hypertrophy that underwent bioprosthetic aortic valve replacement with concomitant septal myectomy. On subsequent follow-up an abnormal flow traversing the septum into the left ventricle was identified and Doppler interrogation demonstrated a continuous flow, with a predominantly diastolic component, consistent with coronary arterial flow. Conclusion The literature on coronary cameral fistulas is reviewed and the etiology of the diagnostic findings discussed. In our patient, a coronary artery to left ventricle fistula was the most likely explanation secondary to trauma to the septal perforator artery during myectomy. Since the patient was asymptomatic at the time of diagnosis no intervention was recommended and has done well on follow-up.

Baicalin Attenuates Hypoxia-Induced Pulmonary Arterial Hypertension to Improve Hypoxic Cor Pulmonale by Reducing the Activity of the p38 MAPK Signaling Pathway and MMP-9

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Shuangquan Yan

2016-01-01

Full Text Available Baicalin has a protective effect on hypoxia-induced pulmonary hypertension in rats, but the mechanism of this effect remains unclear. Thus, investigating the potential mechanism of this effect was the aim of the present study. Model rats that display hypoxic pulmonary hypertension and cor pulmonale under control conditions were successfully generated. We measured a series of indicators to observe the levels of pulmonary arterial hypertension, pulmonary arteriole remodeling, and right ventricular remodeling. We assessed the activation of p38 mitogen-activated protein kinase (MAPK in the pulmonary arteriole walls and pulmonary tissue homogenates using immunohistochemistry and western blot analyses, respectively. The matrix metalloproteinase- (MMP- 9 protein and mRNA levels in the pulmonary arteriole walls were measured using immunohistochemistry and in situ hybridization. Our results demonstrated that baicalin not only reduced p38 MAPK activation in both the pulmonary arteriole walls and tissue homogenates but also downregulated the protein and mRNA expression levels of MMP-9 in the pulmonary arteriole walls. This downregulation was accompanied by the attenuation of pulmonary hypertension, arteriole remodeling, and right ventricular remodeling. These results suggest that baicalin may attenuate pulmonary hypertension and cor pulmonale, which are induced by chronic hypoxia, by downregulating the p38 MAPK/MMP-9 pathway.

Integrating physiological regulation with stem cell and tissue homeostasis

Science.gov (United States)

Nakada, Daisuke; Levi, Boaz P.; Morrison, Sean J.

2015-01-01

Summary Stem cells are uniquely able to self-renew, to undergo multilineage differentiation, and to persist throughout life in a number of tissues. Stem cells are regulated by a combination of shared and tissue-specific mechanisms and are distinguished from restricted progenitors by differences in transcriptional and epigenetic regulation. Emerging evidence suggests that other aspects of cellular physiology, including mitosis, signal transduction, and metabolic regulation also differ between stem cells and their progeny. These differences may allow stem cells to be regulated independently of differentiated cells in response to circadian rhythms, changes in metabolism, diet, exercise, mating, aging, infection, and disease. This allows stem cells to sustain homeostasis or to remodel relevant tissues in response to physiological change. Stem cells are therefore not only regulated by short-range signals that maintain homeostasis within their tissue of origin, but also by long-range signals that integrate stem cell function with systemic physiology. PMID:21609826

Applying the payoff time framework to carotid artery disease management.

Science.gov (United States)

Yuo, Theodore H; Roberts, Mark S; Braithwaite, R Scott; Chang, Chung-Chou H; Kraemer, Kevin L

2013-11-01

and Asymptomatic stenosis of the carotid arteries is associated with stroke. Carotid revascularization can reduce the future risk of stroke but can also trigger an immediate stroke. The objective was to model the generic relationship between immediate risk, long-term benefit, and life expectancy for any one-time prophylactic treatment and then apply the model to the use of revascularization in the management of asymptomatic carotid disease. In the "payoff time" framework, the possibility of losing quality-adjusted life-years (QALYs) because of revascularization failure is conceptualized as an "investment" that is eventually recouped over time, on average. Using this framework, we developed simple mathematical forms that define relationships between the following: perioperative probability of stroke (P); annual stroke rate without revascularization (r0); annual stroke rate after revascularization, conditional on not having suffered perioperative stroke (r1); utility levels assigned to the asymptomatic state (ua) and stroke state (us); and mortality rates (λ). In patients whose life expectancy is below a critical life expectancy (CLE = P/(1-P)r0-r1, the "investment" will never pay off, and revascularization will lead to loss of QALYs, on average. CLE is independent of utilities assigned to the health states if a rank ordering exists in which ua > us. For clinically relevant values (P = 3%, r0 = 1%, r1 = 0.5%), the CLE is approximately 6.4 years, which is longer than published guidelines regarding patient selection for revascularization. In managing asymptomatic carotid disease, the payoff time framework specifies a CLE beneath which patients, on average, will not benefit from revascularization. This formula is suitable for clinical use at the patient's bedside and can account for patient variability, the ability of clinicians who perform revascularization, and the particular revascularization technology that is chosen.

Integrated watershed analysis: adapting to changing times

Science.gov (United States)

Gordon H. Reeves

2013-01-01

Resource managers are increasingly required to conduct integrated analyses of aquatic and terrestrial ecosystems before undertaking any activities. Th ere are a number of research studies on the impacts of management actions on these ecosystems, as well as a growing body of knowledge about ecological processes that aff ect them, particularly aquatic ecosystems, which...

From cells to tissue: A continuum model of epithelial mechanics

Science.gov (United States)

Ishihara, Shuji; Marcq, Philippe; Sugimura, Kaoru

2017-08-01

A two-dimensional continuum model of epithelial tissue mechanics was formulated using cellular-level mechanical ingredients and cell morphogenetic processes, including cellular shape changes and cellular rearrangements. This model incorporates stress and deformation tensors, which can be compared with experimental data. Focusing on the interplay between cell shape changes and cell rearrangements, we elucidated dynamical behavior underlying passive relaxation, active contraction-elongation, and tissue shear flow, including a mechanism for contraction-elongation, whereby tissue flows perpendicularly to the axis of cell elongation. This study provides an integrated scheme for the understanding of the orchestration of morphogenetic processes in individual cells to achieve epithelial tissue morphogenesis.

Forearm arterial anatomy and flow characteristics: a prospective observational study.

Science.gov (United States)

Pancholy, Samir B; Heck, Laura A; Patel, Tejas

2015-04-01

Morphometric data on Caucasian radial and ulnar arteries are limited, with no data on flow interdependence in the forearm arterial circuit. A total of 250 upper extremities in 125 patients were evaluated. Ultrasonography was performed and radial and ulnar artery lumen diameters were measured. Ulnar artery (UA) was compressed at the level of the wrist, and flow parameters in radial artery (RA) were recorded using duplex Doppler ultrasound. Radial and ulnar artery diameters were comparable at the level of the distal forearm (RA = 2.03 ± 0.28 mm, UA = 2.07 ± 0.27 mm; P=.14). There was no significant difference in radial or ulnar artery diameter between the dominant upper extremity and the non-dominant upper extremity. Upon compression of the ulnar artery, radial artery velocity-time integral (VTI) increased from 8.4 ± 3.8 cm to 12.8 ± 5.5 cm, which was statistically significant (Pforearm is comparable to UA. RA-VTI and likely flow significantly increase by compression of the UA. The smaller the radial artery, the larger the increase in radial artery flow with ulnar compression.

Tissue expander-stimulated lengthening of arteries for the treatment of midaortic syndrome in children.

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Kim, Heung Bae; Vakili, Khashayar; Ramos-Gonzalez, Gabriel J; Stein, Deborah R; Ferguson, Michael A; Porras, Diego; Lock, James E; Chaudry, Gulraiz; Alomari, Ahmad; Fishman, Steven J

2018-01-17

Midaortic syndrome (MAS) is a rare condition characterized by stenosis of the abdominal aorta. Patients with disease refractory to medical management will usually require either endovascular therapy or surgery with use of prosthetic graft material for bypass or patch angioplasty. We report our early experience with a novel approach using a tissue expander (TE) to lengthen the normal native arteries in children with MAS, allowing primary aortic repair without the need for prosthetic graft material. We conducted a retrospective review of patients with MAS undergoing the TE-stimulated lengthening of arteries (TESLA) procedure at our institution from 2010 to 2014. Data are presented as mean (range). Five patients aged 4.8 years (3-8 years) underwent the TESLA procedure. Stages of this procedure include the following: stage I, insertion of retroaortic TE; stage II, serial TE injections; and stage III, final repair with excision of aortic stenosis and primary end-to-end aortic anastomosis. Stage II was completed in 4 months (1-9 months) with 12 (7-20) TE injections. Goal lengthening was achieved in all patients. Stage III could not be completed in one patient because of extreme aortic inflammation, which precluded safe excision of the aortic stenosis and required use of a prosthetic bypass graft. The other four patients completed stage III with two (one to three) additional vessels also requiring reconstruction (renal or mesenteric arteries). At 3.2 years (1-6 years) of follow-up, all patients are doing well. The TESLA procedure allows surgical correction of MAS without the need for prosthetic grafts in young children who are still growing. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Use of an Intra-Arterial Catheter as a Provisional Conduit for Regulated Outflow Management in the Setting of Artery-Only Digital Replantation.

Science.gov (United States)

DeFazio, Michael V; Han, Kevin D; Paryavi, Ebrahim

2017-12-01

Successful replantation of distal digital segments necessitates the establishment of sufficient outflow to minimize congestion and progressive tissue necrosis. In cases where only arterial anastomosis is feasible, an artificial outlet must be provided to maintain physiological requirements until microvenous circulation regenerates. This can be accomplished using any number of "exsanguination techniques" designed to facilitate egress through ongoing passive blood loss. Although reportedly effective, these measures are imprecise and carry a substantial risk of infection, scarring, and/or uncontrolled hemorrhage. Herein, we describe a preemptive alternative for provisional venous drainage, whereby direct catheterization of a distal arterial branch is used to enhance the precision of outflow management following artery-only digital replantation. The establishment of intravascular access, using the technique described, permits remote manipulation of the microcirculatory environment through timed administration of heparinized saline and regulated removal of controlled volumes of blood.

Doppler ultrasonography of the pectinis oculi artery in harpy eagles ...

African Journals Online (AJOL)

Low RI and PI values found in the harpy eagle´s pectinis oculi artery compared with the American pekin ducks one and other tissue suggest indeed a high metabolic activity in pecten oculi and corroborates the hypothesis of a nutritional function and/or intraocular pressure regulation. Keywords: Avian posterior segment, ...

Differential Temporal Evolution Patterns in Brain Temperature in Different Ischemic Tissues in a Monkey Model of Middle Cerebral Artery Occlusion

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Zhihua Sun

2012-01-01

Full Text Available Brain temperature is elevated in acute ischemic stroke, especially in the ischemic penumbra (IP. We attempted to investigate the dynamic evolution of brain temperature in different ischemic regions in a monkey model of middle cerebral artery occlusion. The brain temperature of different ischemic regions was measured with proton magnetic resonance spectroscopy (1H MRS, and the evolution processes of brain temperature were compared among different ischemic regions. We found that the normal (baseline brain temperature of the monkey brain was 37.16°C. In the artery occlusion stage, the mean brain temperature of ischemic tissue was 1.16°C higher than the baseline; however, this increase was region dependent, with 1.72°C in the IP, 1.08°C in the infarct core, and 0.62°C in the oligemic region. After recanalization, the brain temperature of the infarct core showed a pattern of an initial decrease accompanied by a subsequent increase. However, the brain temperature of the IP and oligemic region showed a monotonously and slowly decreased pattern. Our study suggests that in vivo measurement of brain temperature could help to identify whether ischemic tissue survives.

Doppler ultrasonography of the pectinis oculi artery in harpy eagles (Harpia harpyja

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Wanderlei de Moraes

2017-03-01

Full Text Available Twenty harpy eagles (Harpia harpyja without systemic or ocular diseases were examined to measure blood velocity parameters of the pectinis oculi artery using Doppler ultrasonography. Pectinate artery resistive index (RI and pulsatility index (PI were investigated using ocular Doppler ultrasonography. The mean RI and PI values across all eyes were 0.44±0.10 and 0.62±0.20 respectively. Low RI and PI values found in the harpy eagle´s pectinis oculi artery compared with the American pekin ducks one and other tissue suggest indeed a high metabolic activity in pecten oculi and corroborates the hypothesis of a nutritional function and/or intraocular pressure regulation.

Intravital live cell triggered imaging system reveals monocyte patrolling and macrophage migration in atherosclerotic arteries

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McArdle, Sara; Chodaczek, Grzegorz; Ray, Nilanjan; Ley, Klaus

2015-02-01

Intravital multiphoton imaging of arteries is technically challenging because the artery expands with every heartbeat, causing severe motion artifacts. To study leukocyte activity in atherosclerosis, we developed the intravital live cell triggered imaging system (ILTIS). This system implements cardiac triggered acquisition as well as frame selection and image registration algorithms to produce stable movies of myeloid cell movement in atherosclerotic arteries in live mice. To minimize tissue damage, no mechanical stabilization is used and the artery is allowed to expand freely. ILTIS performs multicolor high frame-rate two-dimensional imaging and full-thickness three-dimensional imaging of beating arteries in live mice. The external carotid artery and its branches (superior thyroid and ascending pharyngeal arteries) were developed as a surgically accessible and reliable model of atherosclerosis. We use ILTIS to demonstrate Cx3cr1GFP monocytes patrolling the lumen of atherosclerotic arteries. Additionally, we developed a new reporter mouse (Apoe-/-Cx3cr1GFP/+Cd11cYFP) to image GFP+ and GFP+YFP+ macrophages "dancing on the spot" and YFP+ macrophages migrating within intimal plaque. ILTIS will be helpful to answer pertinent open questions in the field, including monocyte recruitment and transmigration, macrophage and dendritic cell activity, and motion of other immune cells.

Incorporating real-time traffic and weather data to explore road accident likelihood and severity in urban arterials.

Science.gov (United States)

Theofilatos, Athanasios

2017-06-01

The effective treatment of road accidents and thus the enhancement of road safety is a major concern to societies due to the losses in human lives and the economic and social costs. The investigation of road accident likelihood and severity by utilizing real-time traffic and weather data has recently received significant attention by researchers. However, collected data mainly stem from freeways and expressways. Consequently, the aim of the present paper is to add to the current knowledge by investigating accident likelihood and severity by exploiting real-time traffic and weather data collected from urban arterials in Athens, Greece. Random Forests (RF) are firstly applied for preliminary analysis purposes. More specifically, it is aimed to rank candidate variables according to their relevant importance and provide a first insight on the potential significant variables. Then, Bayesian logistic regression as well finite mixture and mixed effects logit models are applied to further explore factors associated with accident likelihood and severity respectively. Regarding accident likelihood, the Bayesian logistic regression showed that variations in traffic significantly influence accident occurrence. On the other hand, accident severity analysis revealed a generally mixed influence of traffic variations on accident severity, although international literature states that traffic variations increase severity. Lastly, weather parameters did not find to have a direct influence on accident likelihood or severity. The study added to the current knowledge by incorporating real-time traffic and weather data from urban arterials to investigate accident occurrence and accident severity mechanisms. The identification of risk factors can lead to the development of effective traffic management strategies to reduce accident occurrence and severity of injuries in urban arterials. Copyright © 2017 Elsevier Ltd and National Safety Council. All rights reserved.

Three-dimensional visualization of functional brain tissue and functional magnetic resonance imaging-integrated neuronavigation in the resection of brain tumor adjacent to motor cortex

International Nuclear Information System (INIS)

Han Tong; Cui Shimin; Tong Xiaoguang; Liu Li; Xue Kai; Liu Meili; Liang Siquan; Zhang Yunting; Zhi Dashi

2011-01-01

Objective: To assess the value of three -dimensional visualization of functional brain tissue and the functional magnetic resonance imaging (fMRI)-integrated neuronavigation in the resection of brain tumor adjacent to motor cortex. Method: Sixty patients with tumor located in the central sulcus were enrolled. Thirty patients were randomly assigned to function group and 30 to control group. Patients in function group underwent fMRI to localize the functional brain tissues. Then the function information was transferred to the neurosurgical navigator. The patients in control group underwent surgery with navigation without function information. The therapeutic effect, excision rate. improvement of motor function, and survival quality during follow-up were analyzed. Result: All patients in function group were accomplished visualization of functional brain tissues and fMRI-integrated neuronavigation. The locations of tumors, central sulcus and motor cortex were marked during the operation. The fMRI -integrated information played a great role in both pre- and post-operation. Pre-operation: designing the location of the skin flap and window bone, determining the relationship between the tumor and motor cortex, and designing the pathway for the resection. Post- operation: real-time navigation of relationship between the tumor and motor cortex, assisting to localize the motor cortex using interoperation ultra-sound for correcting the displacement by the CSF outflow and collapsing tumor. The patients in the function group had better results than the patients in the control group in therapeutic effect (u=2.646, P=0.008), excision rate (χ = 7.200, P<0.01), improvement of motor function (u=2.231, P=0.026), and survival quality (KPS u c = 2.664, P=0.008; Zubrod -ECOG -WHO u c =2.135, P=0.033). Conclusions: Using preoperative three -dimensional visualization of cerebral function tissue and the fMRI-integrated neuronavigation technology, combining intraoperative accurate

High-density lipoprotein-based therapy reduces the hemorrhagic complications associated with tissue plasminogen activator treatment in experimental stroke.

Science.gov (United States)

Lapergue, Bertrand; Dang, Bao Quoc; Desilles, Jean-Philippe; Ortiz-Munoz, Guadalupe; Delbosc, Sandrine; Loyau, Stéphane; Louedec, Liliane; Couraud, Pierre-Olivier; Mazighi, Mikael; Michel, Jean-Baptiste; Meilhac, Olivier; Amarenco, Pierre

2013-03-01

We have previously reported that intravenous injection of high-density lipoproteins (HDLs) was neuroprotective in an embolic stroke model. We hypothesized that HDL vasculoprotective actions on the blood-brain barrier (BBB) may decrease hemorrhagic transformation-associated with tissue plasminogen activator (tPA) administration in acute stroke. We used tPA alone or in combination with HDLs in vivo in 2 models of focal middle cerebral artery occlusion (MCAO) (embolic and 4-hour monofilament MCAO) and in vitro in a model of BBB. Sprague-Dawley rats were submitted to MCAO, n=12 per group. The rats were then randomly injected with tPA (10 mg/kg) or saline with or without human plasma purified-HDL (10 mg/kg). The therapeutic effects of HDL and BBB integrity were assessed blindly 24 hours later. The integrity of the BBB was also tested using an in vitro model of human cerebral endothelial cells under oxygen-glucose deprivation. tPA-treated groups had significantly higher mortality and rate of hemorrhagic transformation at 24 hours in both MCAO models. Cotreatment with HDL significantly reduced stroke-induced mortality versus tPA alone (by 42% in filament MCAO, P=0.009; by 73% in embolic MCAO, P=0.05) and tPA-induced intracerebral parenchymal hematoma (by 92% in filament MCAO, by 100% in embolic MCAO; Phemorrhagic transformation in rat models of MCAO. Both in vivo and in vitro results support the vasculoprotective action of HDLs on BBB under ischemic conditions.

Comparing the Effect of Continuous and Intermittent Irrigation Techniques on Complications of Arterial Catheter and Partial Thromboplastin Time in Patients Following Coronary Artery Bypass Grafting Surgery

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Sedigheh Arta

2017-04-01

Full Text Available Background: Different approaches are available to irrigate the arterial catheter, such as continuous and intermittent techniques. However, there is a disagreement regarding the most appropriate method. Aim: this study aimed to compare the effect of two continuous and intermittent irrigation methods on complications of arterial catheter and partial thromboplastin time (PTT in patients with coronary artery bypass (CABG surgery. Method: This randomized clinical trial was conducted on 60 participants undergoing coronary artery bypass grafting surgery in open-heart surgery ICU at Imam Reza hospital in Mashhad, Iran, in 2016. In continuous group, the arterial catheter was continuously irrigated with heparin solution at the rate of 2cc/h, and in the intermittent group with a syringe containing 5cc heparin solution every 3 hours. In both groups, catheter was monitored and recorded every 3 hours (until 48 hours and 3 times from enrollment in terms of complications of partial thromboplastin time. Data were analyzed using SPSS version 16. Results: The findingsof independent t-test showed that the two groups are homogeneous in age (P =0.48. The result of Fisher's exact test revealed no significant difference between the two groups in terms of average incidence of complications during the first 24 hours (P=0.55 and second 24 hours (P=0.55 after catheterization. Also during the 48 hours after surgery, independent t-test results showed no statistically significant difference in partial thromboplastin time (P=0.53 between the two groups. Implications for Practice: According to the results of the research based on the lack of difference between continuous and intermittent irrigation methods up to 48 hours after catheter replacement in terms of arterial catheter complications, further long-term follow-up researches are recommended.

Arterial wave reflection decreases gradually from supine to upright

DEFF Research Database (Denmark)

van den Bogaard, Bas; Westerhof, Berend E; Best, Hendrik

2011-01-01

BACKGROUND. An increase in total peripheral resistance (TPR) usually increases arterial wave reflection. During passive head-up tilt (HUT), however, arterial wave reflection decreases with increasing TPR. This study addressed whether arterial wave reflection gradually decreases during HUT. METHODS....... In 10 healthy volunteers (22-39 years, nine males), we recorded finger arterial pressures in supine position (0°), and 30°and 70°degrees HUT and active standing (90°). Aortic pressure was constructed from the finger pressure signal and hemodynamics were calculated. Arterial wave reflection...... from 0.9 dyn s/cm(5) at 0? to 1.2, 1.4 and 1.4 dyn s/cm(5) at 30°, 70° and 90° (p wave reflection...

Connective tissue activation. XVII

International Nuclear Information System (INIS)

Weiss, J.J.; Donakowski, C.; Anderson, B.; Meyers, S.; Castor, C.W.

1980-01-01

The platelet-derived connective tissue activating peptide (CTAP-III) has been shown to be an important factor stimulating the metabolism and proliferation of human connective tissue cell strains, including synovial tissue cells. The quantities of CTAP-III affecting the cellular changes and the amounts in various biologic fluids and tissues are small. The objectives of this study were to develop a radioimmunoassay (RIA) for CTAP-III and to ascertain the specificities of the anti-CTAP-III sera reagents. The antisera were shown not to cross-react with a number of polypeptide hormones. However, two other platelet proteins β-thromboglobulin and low affinity platelet factor-4, competed equally as well as CTAP-III for anti-CTAP-III antibodies in the RIA system. Thus, the three platelet proteins are similar or identical with respect to those portions of the molecules constituting the reactive antigenic determinants. The levels of material in normal human platelet-free plasma that inhibited anti-CTAP-III- 125 I-CTAP-III complex formation were determined to be 34+-13 (S.D.) ng/ml. (Auth.)

Connective tissue injury in calf muscle tears and return to play: MRI correlation.

Science.gov (United States)

Prakash, Ashutosh; Entwisle, Tom; Schneider, Michal; Brukner, Peter; Connell, David

2017-10-26

The aim of our study was to assess a group of patients with calf muscle tears and evaluate the integrity of the connective tissue boundaries and interfaces. Further, we propose a novel MRI grading system based on integrity of the connective tissue and assess any correlation between the grading score and time to return to play. We have also reviewed the anatomy of the calf muscles. We retrospectively evaluated 100 consecutive patients with clinical suspicion and MRI confirmation of calf muscle injury. We evaluated each calf muscle tear with MRI for the particular muscle injured, location of injury within the muscle and integrity of the connective tissue structure at the interface. The muscle tears were graded 0-3 depending on the degree of muscle and connective tissue injury. The time to return to play for each patient and each injury was found from the injury records and respective sports doctors. In 100 patients, 114 injuries were detected. Connective tissue involvement was observed in 63 out of 100 patients and failure (grade 3 injury) in 18. Mean time to return to play with grade 0 injuries was 8 days, grade 1 tears was 17 days, grade 2 tears was 25 days and grade 3 tears was 48 days (pmuscle tears. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Massive hemothorax due to inferior phrenic artery injury after blunt trauma.

Science.gov (United States)

Aoki, Makoto; Shibuya, Kei; Kaneko, Minoru; Koizumi, Ayana; Murata, Masato; Nakajima, Jun; Hagiwara, Shuichi; Kanbe, Masahiko; Koyama, Yoshinori; Tsushima, Yoshito; Oshima, Kiyohiro

2015-01-01

Injury to the inferior phrenic artery after blunt trauma is an extremely rare event, and it may occur under unanticipated conditions. This case report describes an injury to the left inferior phrenic artery caused by blunt trauma, which was complicated by massive hemothorax, and treated with transcatheter arterial embolization (TAE). An 81 year-old female hit by a car while walking at the traffic intersection was transferred to the emergency department, computed tomography scanning revealed active extravasations of the contrast medium within the retrocrural space and from branches of the internal iliac artery. The patient underwent repeated angiography, and active extravasation of contrast medium was observed between the retrocrural space and the right pleural space originating from the left inferior phrenic artery. The injured left inferior phrenic artery was successfully embolized with N-butyl cyanoacrylate, resulting in stabilization of the patient's clinical condition. Inferior phrenic artery injury should be recognized as a rare phenomenon and causative factor for hemothorax. TAE represents a safe and effective treatment for this complication and obviates the need for a thoracotomy.

Matriptase activation connects tissue factor-dependent coagulation initiation to epithelial proteolysis and signaling.

Science.gov (United States)

Le Gall, Sylvain M; Szabo, Roman; Lee, Melody; Kirchhofer, Daniel; Craik, Charles S; Bugge, Thomas H; Camerer, Eric

2016-06-23

The coagulation cascade is designed to sense tissue injury by physical separation of the membrane-anchored cofactor tissue factor (TF) from inactive precursors of coagulation proteases circulating in plasma. Once TF on epithelial and other extravascular cells is exposed to plasma, sequential activation of coagulation proteases coordinates hemostasis and contributes to host defense and tissue repair. Membrane-anchored serine proteases (MASPs) play critical roles in the development and homeostasis of epithelial barrier tissues; how MASPs are activated in mature epithelia is unknown. We here report that proteases of the extrinsic pathway of blood coagulation transactivate the MASP matriptase, thus connecting coagulation initiation to epithelial proteolysis and signaling. Exposure of TF-expressing cells to factors (F) VIIa and Xa triggered the conversion of latent pro-matriptase to an active protease, which in turn cleaved the pericellular substrates protease-activated receptor-2 (PAR2) and pro-urokinase. An activation pathway-selective PAR2 mutant resistant to direct cleavage by TF:FVIIa and FXa was activated by these proteases when cells co-expressed pro-matriptase, and matriptase transactivation was necessary for efficient cleavage and activation of wild-type PAR2 by physiological concentrations of TF:FVIIa and FXa. The coagulation initiation complex induced rapid and prolonged enhancement of the barrier function of epithelial monolayers that was dependent on matriptase transactivation and PAR2 signaling. These observations suggest that the coagulation cascade engages matriptase to help coordinate epithelial defense and repair programs after injury or infection, and that matriptase may contribute to TF-driven pathogenesis in cancer and inflammation.

Coronary artery wall imaging in mice using osmium tetroxide and micro-computed tomography (micro-CT)

International Nuclear Information System (INIS)

Pai, Vinay M.; Kozlowski, Megan; Donahue, Danielle; Miller, Elishiah; Xiao, Xianghui; Chen, Marcus Y.; Yu, Zu-Xi; Connelly, Patricia; Jeffries, Kenneth; Wen, Han

2012-01-01

The high spatial resolution of micro-computed tomography (micro-CT) is ideal for 3D imaging of coronary arteries in intact mouse heart specimens. Previously, micro-CT of mouse heart specimens utilized intravascular contrast agents that hardened within the vessel lumen and allowed a vascular cast to be made. However, for mouse coronary artery disease models, it is highly desirable to image coronary artery walls and highlight plaques. For this purpose, we describe an ex vivo contrast-enhanced micro-CT imaging technique based on tissue staining with osmium tetroxide (OsO 4 ) solution. As a tissue-staining contrast agent, OsO 4 is retained in the vessel wall and surrounding tissue during the fixation process and cleared from the vessel lumens. Its high X-ray attenuation makes the artery wall visible in CT. Additionally, since OsO 4 preferentially binds to lipids, it highlights lipid deposition in the artery wall. We performed micro-CT of heart specimens of 5- to 25-week-old C57BL/6 wild-type mice and 5- to 13-week-old apolipoprotein E knockout (apoE -/- ) mice at 10 μm resolution. The results show that walls of coronary arteries as small as 45 μm in diameter are visible using a table-top micro-CT scanner. Similar image clarity was achieved with 1/2000th the scan time using a synchrotron CT scanner. In 13-week-old apoE mice, lipid-rich plaques are visible in the aorta. Our study shows that the combination of OsO 4 and micro-CT permits the visualization of the coronary artery wall in intact mouse hearts.

Imagenology of the bio integration of polymers synthesized by plasma in pith tissue

International Nuclear Information System (INIS)

Morales, J.; Olayo, R.; Escalona, A.; Morales, A.; Mondragon, R.; Diaz, A.; Rios, C.; Salgado, H.; Cruz, G.; Olayo, M.G.

2007-01-01

The general characteristics of the bio integration of pyrrole derived polymers in spinal marrows with traumatic lesions are evaluated by visual mediums. Histological images of spinal marrow tinted by the Eosin/Hematoxyline technique are used and images obtained by computerized axial tomography and nuclear magnetic resonance with those that are carried out some three-dimensional reconstructions of the injured area. It intends an algorithm that relates the area of the bottom-tissue relationship with the sum of the tissue areas and of the implanted polymer. Some computational procedures for segmentation of spinal marrow on the integration of the polymer to the tissue of the injured marrow are presented. (Author)

Purification and characterization of a 3'-phosphoadenylylsulfate:chondroitin 6-sulfotransferase from arterial tissue.

Science.gov (United States)

Hollmann, J; Niemann, R; Buddecke, E

1986-01-01

A 3'-phosphoadenylylsulfate:chondroitin sulfotransferase (EC 2.8.2.5) was purified to homogeneity (about 760-fold) from the cytosolic fraction of calf arterial tissue by Con A-Sepharose, ion exchange and affinity chromatography. The enzyme has a molecular mass of 38000 Da, optimal activity at pH 6.0 (100%) and 7.25 (75%), requires divalent cations for maximal activity (Mn2+ greater than Mg2+, Ca2+) and exhibits specificity towards desulfated chondroitin sulfate and oligosaccharides derived therefrom. The enzyme transfers sulfate groups from [35S]phosphoadenylylsulfate exclusively to C-6 OH groups of N-acetylgalactosamine units of the acceptor substrates. Maximal sulfate transfer occurs at 2mM chondroitin disaccharide units (100%), the transfer rates decreasing with decreasing chain length in the order deca (55%), octa (17%) and hexasaccharides (4%). Lineweaver-Burk plots revealed equal maximal velocities for chondroitin, deca-, octa- and hexasaccharide, but decreasing Km values. Chondroitin 4-sulfate has 21% of the acceptor potency exhibited by chondroitin, whereas dermatan sulfate, heparan sulfate and hyaluronate and the chondroitin tetrasaccharide showed no acceptor properties. Analysis of the reaction products formed by prolonged enzymatic sulfation of a reduced chondroitin hexasaccharide [GlcA-GalNAc]2-GlcA-GalNAc-ol revealed that the preterminal N-acetylgalactosamine from the non-reducing end and the internal N-acetylgalactosamine but not the N-acetylgalactosaminitol were sulfated and that no hexasaccharide disulfate was formed by the action of chondroitin 6-sulfotransferase. Chondroitin 6-sulfotransferase is considered to possess a binding region capable of accommodating a nonsulfated oligosaccharide sequence of at least six sugars and is believed to act in the course of chondroitin sulfate synthesis in cooperation with, but shortly after, the enzymes involved in the chain elongation reaction.

Slack length reduces the contractile phenotype of the Swine carotid artery.

Science.gov (United States)

Rembold, Christopher M; Garvey, Sean M; Tejani, Ankit D

2013-01-01

Contraction is the primary function of adult arterial smooth muscle. However, in response to vessel injury or inflammation, arterial smooth muscle is able to phenotypically modulate from the contractile state to several 'synthetic' states characterized by proliferation, migration and/or increased cytokine secretion. We examined the effect of tissue length (L) on the phenotype of intact, isometrically held, initially contractile swine carotid artery tissues. Tissues were studied (1) without prolonged incubation at the optimal length for force generation (1.0 Lo, control), (2) with prolonged incubation for 17 h at 1.0 Lo, or (3) with prolonged incubation at slack length (0.6 Lo) for 16 h and then restoration to 1.0 Lo for 1 h. Prolonged incubation at 1.0 Lo minimally reduced the contractile force without substantially altering the mediators of contraction (crossbridge phosphorylation, shortening velocity or stimulated actin polymerization). Prolonged incubation of tissues at slack length (0.6 Lo), despite return of length to 1.0 Lo, substantially reduced contractile force, reduced crossbridge phosphorylation, nearly abolished crossbridge cycling (shortening velocity) and abolished stimulated actin polymerization. These data suggest that (1) slack length treatment significantly alters the contractile phenotype of arterial tissue, and (2) slack length treatment is a model to study acute phenotypic modulation of intact arterial smooth muscle. Copyright © 2013 S. Karger AG, Basel.

Tissue and plasma enzyme activities in juvenile green iguanas.

Science.gov (United States)

Wagner, R A; Wetzel, R

1999-02-01

To determine activities of intracellular enzymes in 8 major organs in juvenile green iguanas and to compare tissue and plasma activities. 6 green iguanas iguanas, but high values may not always indicate overt muscle disease. The AMS activity may be specific for the pancreas, but the wide range of plasma activity would likely limit its diagnostic usefulness. Activities of AST and LDH may reflect tissue damage or inflammation, but probably do not reflect damage to specific tissues or organs.

Monolitic integrated circuit for the strobed charge-to-time converter

International Nuclear Information System (INIS)

Bel'skij, V.I.; Bushnin, Yu.B.; Zimin, S.A.; Punzhin, Yu.N.; Sen'ko, V.A.; Soldatov, M.M.; Tokarchuk, V.P.

1985-01-01

The developed and comercially produced semiconducting circuit - gating charge-to-time converter KR1101PD1 is described. The considered integrated circuit is a short pulse charge-to-time converter with integration of input current. The circuit is designed for construction of time-to-pulse analog-to-digital converters utilized in multichannel detection systems when studying complex topology processes. Input resistance of the circuit is 0.1 Ω permissible input current is 50 mA, maximum measured charge is 300-1000 pC

A curve-fitting approach to estimate the arterial plasma input function for the assessment of glucose metabolic rate and response to treatment.

Science.gov (United States)

Vriens, Dennis; de Geus-Oei, Lioe-Fee; Oyen, Wim J G; Visser, Eric P

2009-12-01

For the quantification of dynamic (18)F-FDG PET studies, the arterial plasma time-activity concentration curve (APTAC) needs to be available. This can be obtained using serial sampling of arterial blood or an image-derived input function (IDIF). Arterial sampling is invasive and often not feasible in practice; IDIFs are biased because of partial-volume effects and cannot be used when no large arterial blood pool is in the field of view. We propose a mathematic function, consisting of an initial linear rising activity concentration followed by a triexponential decay, to describe the APTAC. This function was fitted to 80 oncologic patients and verified for 40 different oncologic patients by area-under-the-curve (AUC) comparison, Patlak glucose metabolic rate (MR(glc)) estimation, and therapy response monitoring (Delta MR(glc)). The proposed function was compared with the gold standard (serial arterial sampling) and the IDIF. To determine the free parameters of the function, plasma time-activity curves based on arterial samples in 80 patients were fitted after normalization for administered activity (AA) and initial distribution volume (iDV) of (18)F-FDG. The medians of these free parameters were used for the model. In 40 other patients (20 baseline and 20 follow-up dynamic (18)F-FDG PET scans), this model was validated. The population-based curve, individually calibrated by AA and iDV (APTAC(AA/iDV)), by 1 late arterial sample (APTAC(1 sample)), and by the individual IDIF (APTAC(IDIF)), was compared with the gold standard of serial arterial sampling (APTAC(sampled)) using the AUC. Additionally, these 3 methods of APTAC determination were evaluated with Patlak MR(glc) estimation and with Delta MR(glc) for therapy effects using serial sampling as the gold standard. Excellent individual fits to the function were derived with significantly different decay constants (P AUC from APTAC(AA/iDV), APTAC(1 sample), and APTAC(IDIF) with the gold standard (APTAC(sampled)) were 0

Lateral abdominal wall hematoma as a rare complication after carotid artery stenting: a case report

Directory of Open Access Journals (Sweden)

Satomi Jyunichiro

2009-11-01

Full Text Available Abstract Abdominal wall hematoma is a rare and life-threatening complication after carotid artery stenting (CAS, but it can occur when activated clotting time is prolonged. We report a right lateral abdominal wall hematoma caused by rupture of the superficial circumflex iliac artery after CAS in a 72-year-old man with severe stenosis of the origin of the right internal carotid artery. We performed CAS for the targeted lesion while activated clotting time exceeded 300 seconds. After 2 hours, he complained of right lateral abdominal pain. Abdominal computed tomography revealed an extensive hematoma in the right lateral abdominal wall. Activated clotting time was 180 seconds at this point. Seven hours later, he developed hypotension and hemoglobin level dropped to 11.3 g/dl. Subsequent computed tomography showed enlargement of the hematoma. Emergent selective angiography of the external iliac artery revealed active bleeding from the right superficial circumflex iliac artery. Transcatheter arterial embolization with Gelfoam and microcoils was performed successfully. With more CAS procedures being performed, it is important for endovascular surgeons and radiologists to consider the possibility of abdominal wall hematoma in this situation.

Interlaced photoacoustic and ultrasound imaging system with real-time coregistration for ovarian tissue characterization

Science.gov (United States)

Alqasemi, Umar; Li, Hai; Yuan, Guangqian; Kumavor, Patrick; Zanganeh, Saeid; Zhu, Quing

2014-07-01

Coregistered ultrasound (US) and photoacoustic imaging are emerging techniques for mapping the echogenic anatomical structure of tissue and its corresponding optical absorption. We report a 128-channel imaging system with real-time coregistration of the two modalities, which provides up to 15 coregistered frames per second limited by the laser pulse repetition rate. In addition, the system integrates a compact transvaginal imaging probe with a custom-designed fiber optic assembly for in vivo detection and characterization of human ovarian tissue. We present the coregistered US and photoacoustic imaging system structure, the optimal design of the PC interfacing software, and the reconfigurable field programmable gate array operation and optimization. Phantom experiments of system lateral resolution and axial sensitivity evaluation, examples of the real-time scanning of a tumor-bearing mouse, and ex vivo human ovaries studies are demonstrated.

Optimization of three-dimensional time-of-flight magnetic resonance angiography of the intracranial arteries

International Nuclear Information System (INIS)

Harada, Kuniaki; Honmou, Osamu; Odawara, Yoshihiro; Bando, Michio; Houkin, Kiyohiro

2006-01-01

The signal-to-noise ratio obtained from arteries in three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography is often too low to allow clinical diagnosis because the radiofrequency pulse decreases the magnetization of protons in the blood and suppresses the in-flow effect in the slab. The present study adjusted the position of the head coil to boost arterial signal intensity. Ten healthy volunteers, eight men and two women aged 24-78 years, underwent 3D TOF MR angiography of the intracranial arteries with the same standard GE transmit-receive birdcage head coil using both normal and half position (lower edge of the coil level with the mouth) methods. Our subjects were divided into Group 1 consisted of five relatively young volunteers aged 24-42 years (mean 31.2 years), and Group 2 consisted of five older volunteers aged 70-78 years (mean 73 years). The following four arteries were chosen for analysis: the internal carotid artery (ICA), the proximal middle cerebral artery segment (M 1 ), and the two distal middle cerebral artery segments (M 2 , M 3 ). The half position method increased the signal-to-noise ratio in the ICA, M 1 , M 2 , and M 3 by 15%, 25%, 36%, and 44%, respectively. In general, this method resulted in the generation of stronger signals in the M 2 and M 3 in younger subjects and in all arteries examined in older subjects. The half position method can provide better MR angiograms in certain brain regions of younger people, and in all brain regions in older patients. (author)

Acute transplant renal artery thrombosis due to distal renal artery stenosis: A case report and review of the literature

OpenAIRE

Fallahzadeh, Mohammad Kazem; Yatavelli, Rajini Kanth; Kumar, Ajay; Singh, Neeraj

2014-01-01

Background: Acute renal artery thrombosis is a devastating complication of renal transplantation that can result in graft loss if not detected early. Surgical and technical errors are the major cause of renal artery thrombosis. In this article, for the first time, we are reporting a case of acute renal artery thrombosis that developed early post-transplantation due to distal renal artery stenosis. Case Presentation: A 71-year-old woman presented with nausea, vomiting and decreased urine outpu...

Simultaneous inference of phenotype-associated genes and relevant tissues from GWAS data via Bayesian integration of multiple tissue-specific gene networks.

Science.gov (United States)

Wu, Mengmeng; Lin, Zhixiang; Ma, Shining; Chen, Ting; Jiang, Rui; Wong, Wing Hung

2017-12-01

Although genome-wide association studies (GWAS) have successfully identified thousands of genomic loci associated with hundreds of complex traits in the past decade, the debate about such problems as missing heritability and weak interpretability has been appealing for effective computational methods to facilitate the advanced analysis of the vast volume of existing and anticipated genetic data. Towards this goal, gene-level integrative GWAS analysis with the assumption that genes associated with a phenotype tend to be enriched in biological gene sets or gene networks has recently attracted much attention, due to such advantages as straightforward interpretation, less multiple testing burdens, and robustness across studies. However, existing methods in this category usually exploit non-tissue-specific gene networks and thus lack the ability to utilize informative tissue-specific characteristics. To overcome this limitation, we proposed a Bayesian approach called SIGNET (Simultaneously Inference of GeNEs and Tissues) to integrate GWAS data and multiple tissue-specific gene networks for the simultaneous inference of phenotype-associated genes and relevant tissues. Through extensive simulation studies, we showed the effectiveness of our method in finding both associated genes and relevant tissues for a phenotype. In applications to real GWAS data of 14 complex phenotypes, we demonstrated the power of our method in both deciphering genetic basis and discovering biological insights of a phenotype. With this understanding, we expect to see SIGNET as a valuable tool for integrative GWAS analysis, thereby boosting the prevention, diagnosis, and treatment of human inherited diseases and eventually facilitating precision medicine.

Sharp Dissection versus Electrocautery for Radial Artery Harvesting

Science.gov (United States)

Marzban, Mehrab; Arya, Reza; Mandegar, Mohammad Hossein; Karimi, Abbas Ali; Abbasi, Kiomars; Movahed, Namvar; Abbasi, Seyed Hesameddin

2006-01-01

Radial arteries have been increasingly used during the last decade as conduits for coronary artery revascularization. Although various harvesting techniques have been described, there has been little comparative study of arterial damage and patency. A radial artery graft was used in 44 consecutive patients, who were randomly divided into 2 groups. In the 1st group, the radial artery was harvested by sharp dissection and in the 2nd, by electrocautery. These groups were compared with regard to radial artery free flow, harvest time, number of clips used, complications, and endothelial damage. Radial artery free flow before and after intraluminal administration of papaverine was significantly greater in the electrocautery group (84.3 ± 50.7 mL/min and 109.7 ± 68.5 mL/min) than in the sharp-dissection group (52.9 ± 18.3 mL/min and 69.6 ± 28.2 mL/ min) (P =0.003). Harvesting time by electrocautery was significantly shorter (25.4 ± 4.3 min vs 34.4 ± 5.9 min) (P =0.0001). Electrocautery consumed an average of 9.76 clips, versus 22.45 clips consumed by sharp dissection. The 2 groups were not different regarding postoperative complications, except for 3 cases of temporary paresthesia of the thumb in the electrocautery group; histopathologic examination found no endothelial damage. We conclude that radial artery harvesting by electrocautery is faster and more economical than harvesting by sharp dissection and is associated with better intraoperative flow and good preservation of endothelial integrity. PMID:16572861

Contribution of NADPH Oxidase to Membrane CD38 Internalization and Activation in Coronary Arterial Myocytes

Science.gov (United States)

Xu, Ming; Li, Xiao-Xue; Ritter, Joseph K.; Abais, Justine M.; Zhang, Yang; Li, Pin-Lan

2013-01-01

The CD38-ADP-ribosylcyclase-mediated Ca2+ signaling pathway importantly contributes to the vasomotor response in different arteries. Although there is evidence indicating that the activation of CD38-ADP-ribosylcyclase is associated with CD38 internalization, the molecular mechanism mediating CD38 internalization and consequent activation in response to a variety of physiological and pathological stimuli remains poorly understood. Recent studies have shown that CD38 may sense redox signals and is thereby activated to produce cellular response and that the NADPH oxidase isoform, NOX1, is a major resource to produce superoxide (O2 ·−) in coronary arterial myocytes (CAMs) in response to muscarinic receptor agonist, which uses CD38-ADP-ribosylcyclase signaling pathway to exert its action in these CAMs. These findings led us hypothesize that NOX1-derived O2 ·− serves in an autocrine fashion to enhance CD38 internalization, leading to redox activation of CD38-ADP-ribosylcyclase activity in mouse CAMs. To test this hypothesis, confocal microscopy, flow cytometry and a membrane protein biotinylation assay were used in the present study. We first demonstrated that CD38 internalization induced by endothelin-1 (ET-1) was inhibited by silencing of NOX1 gene, but not NOX4 gene. Correspondingly, NOX1 gene silencing abolished ET-1-induced O2 ·− production and increased CD38-ADP-ribosylcyclase activity in CAMs, while activation of NOX1 by overexpression of Rac1 or Vav2 or administration of exogenous O2 ·− significantly increased CD38 internalization in CAMs. Lastly, ET-1 was found to markedly increase membrane raft clustering as shown by increased colocalization of cholera toxin-B with CD38 and NOX1. Taken together, these results provide direct evidence that Rac1-NOX1-dependent O2 ·− production mediates CD38 internalization in CAMs, which may represent an important mechanism linking receptor activation with CD38 activity in these cells. PMID:23940720

Time-of-flight depth image enhancement using variable integration time

Science.gov (United States)

Kim, Sun Kwon; Choi, Ouk; Kang, Byongmin; Kim, James Dokyoon; Kim, Chang-Yeong

2013-03-01

Time-of-Flight (ToF) cameras are used for a variety of applications because it delivers depth information at a high frame rate. These cameras, however, suffer from challenging problems such as noise and motion artifacts. To increase signal-to-noise ratio (SNR), the camera should calculate a distance based on a large amount of infra-red light, which needs to be integrated over a long time. On the other hand, the integration time should be short enough to suppress motion artifacts. We propose a ToF depth imaging method to combine advantages of short and long integration times exploiting an imaging fusion scheme proposed for color imaging. To calibrate depth differences due to the change of integration times, a depth transfer function is estimated by analyzing the joint histogram of depths in the two images of different integration times. The depth images are then transformed into wavelet domains and fused into a depth image with suppressed noise and low motion artifacts. To evaluate the proposed method, we captured a moving bar of a metronome with different integration times. The experiment shows the proposed method could effectively remove the motion artifacts while preserving high SNR comparable to the depth images acquired during long integration time.

Time to achieve target mean arterial pressure during resuscitation from experimental anaphylactic shock in an animal model. A comparison of adrenaline alone or in combination with different volume expanders.

Science.gov (United States)

Tajima, K; Zheng, F; Collange, O; Barthel, G; Thornton, S N; Longrois, D; Levy, B; Audibert, G; Malinovsky, J M; Mertes, P M

2013-11-01

Anaphylactic shock is a rare, but potentially lethal complication, combining life-threatening circulatory failure and massive fluid shifts. Treatment guidelines rely on adrenaline and volume expansion by intravenous fluids, but there is no solid evidence for the choice of one specific type of fluid over another. Our purpose was to compare the time to achieve target mean arterial pressure upon resuscitation using adrenaline alone versus adrenaline with different resuscitation fluids in an animal model and to compare the tissue oxygen pressures (PtiO2) with the various strategies. Twenty-five ovalbumin-sensitised Brown Norway rats were allocated to five groups after anaphylactic shock induction: vehicle (CON), adrenaline alone (AD), or adrenaline with isotonic saline (AD+IS), hydroxyethyl starch (AD+HES) or hypertonic saline (AD+HS). Time to reach a target mean arterial pressure value of 75 mmHg, cardiac output, skeletal muscle PtiO2, lactate/pyruvate ratio and cumulative doses of adrenaline were recorded. Non-treated rats died within 15 minutes. The target mean arterial pressure value was reached faster with AD+HES (median: 10 minutes, range: 7.5 to 12.5 minutes) and AD+IS (median: 17.5 minutes, range: 5 to 25 minutes) versus adrenaline alone (median: 25 minutes, range: 20-30 minutes). There were also reduced adrenaline requirements in these groups. The skeletal muscle PtiO2 was restored only in the AD+HES group. Although direct extrapolation to humans should be made with caution, our results support the combined use of adrenaline and volume expansion for resuscitation from anaphylactic shock. When used with adrenaline the most effective fluid was hydroxyethyl starch, whereas hypertonic saline was the least effective.

A school excursion to a museum can promote physical activity in children by integrating movement into curricular activities

DEFF Research Database (Denmark)

Mygind, Lærke; Kryger, Tine; Sidenius, Gry

2017-01-01

Since children spend a large proportion of their time in institutional settings such as schools, health promotion researchers have identified this as an important setting to promote physical activity (PA). Apart from physical education, PA could be integrated into the school curriculum in other...... consisted of an excursion day to a museum. While an increase in light physical activity and reduction in the amount of sedentary time was observed, students did not spend more time in moderate to vigorous PA (MVPA) during the visit to the museum than on a regular school day. However, over the full excursion...... day, the students accumulated more MVPA. One school used active transportation to and from the museum, which contributed to significantly more MVPA compared to the other schools. An excursion to a museum significantly reduced sedentary time, but was in itself not sufficient to increase MVPA....

A school excursion to a museum can promote physical activity in children by integrating movement into curricular activities

DEFF Research Database (Denmark)

Mygind, Lærke; Kryger, Tine B; Sidenius, Gry

2018-01-01

day, the students accumulated more MVPA. One school used active transportation to and from the museum, which contributed to significantly more MVPA compared to the other schools. An excursion to a museum significantly reduced sedentary time, but was in itself not sufficient to increase MVPA.......Since children spend a large proportion of their time in institutional settings such as schools, health promotion researchers have identified this as an important setting to promote physical activity (PA). Apart from physical education, PA could be integrated into the school curriculum in other...... consisted of an excursion day to a museum. While an increase in light physical activity and reduction in the amount of sedentary time was observed, students did not spend more time in moderate to vigorous PA (MVPA) during the visit to the museum than on a regular school day. However, over the full excursion...