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1

Ultrasound RF time series for tissue typing: first in vivo clinical results  

NASA Astrophysics Data System (ADS)

The low diagnostic value of ultrasound in prostate cancer imaging has resulted in an effort to enhance the tumor contrast using ultrasound-based technologies that go beyond traditional B-mode imaging. Ultrasound RF time series, formed by echo samples originating from the same location over a few seconds of imaging, has been proposed and experimentally used for tissue typing with the goal of cancer detection. In this work, for the first time we report the preliminary results of in vivo clinical use of spectral parameters extracted from RF time series in prostate cancer detection. An image processing pipeline is designed to register the ultrasound data to wholemount histopathology references acquired from prostate specimens that are removed in radical prostatectomy after imaging. Support vector machine classification is used to detect cancer in 524 regions of interest of size 5×5 mm, each forming a feature vector of spectral RF time series parameters. Preliminary ROC curves acquired based on RF time series analysis for individual cases, with leave-one-patient-out cross validation, are presented and compared with B-mode texture analysis.

Moradi, Mehdi; Mahdavi, S. Sara; Nir, Guy; Jones, Edward C.; Goldenberg, S. Larry; Salcudean, Septimiu E.

2013-03-01

2

Ultrasound-triggered Release of Recombinant Tissue-type Plasminogen Activator from Echogenic Liposomes  

PubMed Central

Echogenic liposomes (ELIP) were developed as ultrasound-triggered targeted drug or gene delivery vehicles (Lanza et al., 1997; Huang et al., 2001). Recombinant tissue-type Plasminogen Activator (rt-PA), a thrombolytic, has been loaded into ELIP (Tiukinhoy-Laing et al., 2007). These vesicles have the potential to be used for ultrasound-enhanced thrombolysis in the treatment of acute ischemic stroke, myocardial infarction, deep vein thrombosis, or pulmonary embolus. A clinical diagnostic ultrasound scanner (Philips HDI 5000) equipped with a linear array transducer (L12-5) was employed for in vitro studies using rt-PA-loaded ELIP (T-ELIP). The goal of this study was to quantify ultrasound-triggered drug release from rt-PA-loaded echogenic liposomes. T-ELIP samples were exposed to 6.9-MHz B-mode pulses at a low pressure amplitude (600 kPa) to track the echogenicity over time under four experimental conditions: 1) flow alone to monitor gas diffusion from the T-ELIP, 2) pulsed 6.0-MHz color Doppler exposure above the acoustically driven threshold (0.8 MPa) to force gas out of the liposome gently, 3) pulsed 6.0-MHz color Doppler above the rapid fragmentation threshold (2.6 MPa), or 4) Triton X-100 to rupture the T-ELIP chemically as a positive control. Release of rt-PA for each ultrasound exposure protocol was assayed spectrophotometrically. T-ELIP were echogenic in the flow model (5 ml/min) for thirty minutes. The thrombolytic drug remained associated with the liposome when exposed to low-amplitude B-mode pulses over 60 min and was released when exposed to color Doppler pulses or Triton X-100. The rt-PA released from the liposomes had similar enzymatic activity as the free drug. These T-ELIP are robust and echogenic during continuous fundamental 6.9-MHz B-mode imaging at a low exposure output level (600 kPa). Furthermore, a therapeutic concentration of rt-PA can be released by fragmenting the T-ELIP with pulsed 6.0-MHz color Doppler ultrasound above the rapid fragmentation threshold (1.59 MPa). PMID:19900755

Smith, Denise A.B.; Vaidya, Sampada S.; Kopechek, Jonathan A.; Huang, Shao-Ling; Klegerman, Melvin E.; McPherson, David D.; Holland, Christy K.

2009-01-01

3

Ultrasound-targeted transfection of tissue-type plasminogen activator gene carried by albumin nanoparticles to dog myocardium to prevent thrombosis after heart mechanical valve replacement  

PubMed Central

Background There are more than 300,000 prosthetic heart valve replacements each year worldwide. These patients are faced with a higher risk of thromboembolic events after heart valve surgery and long-term or even life-long anticoagulative and antiplatelet therapies are necessary. Some severe complications such as hemorrhaging or rebound thrombosis can occur when the therapy ceases. Tissue-type plasminogen activator (t-PA) is a thrombolytic agent. One of the best strategies is gene therapy, which offers a local high expression of t-PA over a prolonged time period to avoid both systemic hemorrhaging and local rebound thrombosis. There are some issues with t-PA that need to be addressed: currently, there is no up-to-date report on how the t-PA gene targets the heart in vivo and the gene vector for t-PA needs to be determined. Aims To fabricate an albumin nano-t-PA gene ultrasound-targeted agent and investigate its targeting effect on prevention of thrombosis after heart mechanic valve replacement under therapeutic ultrasound. Methods A dog model of mechanical tricuspid valve replacement was constructed. A highly expressive t-PA gene plasmid was constructed and packaged by nanoparticles prepared with bovine serum albumin. This nanopackaged t-PA gene plasmid was further cross-linked to ultrasonic microbubbles prepared with sucrose and bovine serum albumin to form the ultrasonic-targeted agent for t-PA gene transfection. The agent was given intravenously followed by a therapeutic ultrasound treatment (1 MHz, 1.5 w/cm2, 10 minutes) of the heart soon after valve replacement had been performed. The expression of t-PA in myocardium was detected with multiclonal antibodies to t-PA by the indirect immunohistochemical method. Venous blood t-PA and D-dimer contents were tested before and 1, 2, 4, and 8 weeks after the operation. Results The high expression of t-PA could be seen in myocardium with increases in blood t-PA and D-dimer contents and thrombosis was prevented 8 weeks after operation. Conclusion We successfully fabricated an albumin nano-t-PA gene ultrasound-targeted agent that could prevent dog thrombosis after mechanical heart valve replacement. Our study provides an experimental basis for prevention of human thrombosis-related diseases. PMID:22787391

Ji, Jun; Ji, Shang-Yi; Yang, Jian-An; He, Xia; Yang, Xiao-Han; Ling, Wen-Ping; Chen, Xiao-Ling

2012-01-01

4

Tissue mimicking materials for dental ultrasound  

PubMed Central

While acoustic tissue mimicking materials have been explored for a variety of soft and hard biological tissues, no dental hard tissue mimicking materials have been characterized. Tooth phantoms are necessary to better understand acoustic phenomenology within the tooth environment and to accelerate the advancement of dental ultrasound imaging systems. In this study, soda lime glass and dental composite were explored as surrogates for human enamel and dentin, respectively, in terms of compressional velocity, attenuation, and acoustic impedance. The results suggest that a tooth phantom consisting of glass and composite can effectively mimic the acoustic behavior of a natural human tooth. PMID:18396919

Singh, Rahul S.; Culjat, Martin O.; Grundfest, Warren S.; Brown, Elliott R.; White, Shane N.

2008-01-01

5

Tissue temperatures during ultrasound-assisted lipoplasty.  

PubMed

Removing excess subcutaneous fat with the assistance of ultrasonic energy has recently become a technique of interest in the United States after nearly a decade of use in Europe. There are a number of reported advantages of ultrasound-assisted lipoplasty over traditional liposuction, and there are also some theoretical concerns. Ultrasound-assisted lipoplasty involves the conversion of electrical energy to mechanical energy and transfer to the tissues through acoustic pressure waves, with the formation of heat as a by-product. Heat generated in this process dissipates through the body's own cooling mechanisms and conduction to the surrounding tissues, and it does not contribute to the clinical treatment of the adipose tissue. Reports of "burns" and ischemic skin injuries in the literature, and concerns for potential heat-related problems, prompted us to investigate whether significant temperature elevations occur in the clinical setting. Subcutaneous tissue temperature determinations during ultrasound-assisted lipoplasty were begun in February of 1996, and data were collected from 55 patients who had the procedure performed during a 6-month period. Intraoperatively, temperature measurements were made with a data-logging instrument and a needle microprobe inserted into the subcutaneous tissues. Temperatures were taken in the area of liposuction before the infusion of tumescent fluid, after tumescent fluid infusion, and at 5-minute intervals until the end of the procedure. The patient's core body temperature remained stable during the procedure within a narrow range (35.7 degrees C to 36.3 degrees C). There was a gradual increase in the temperature of the subcutaneous tissues over time during the application of ultrasonic energy; however, average subcutaneous temperatures remained below the core temperature (p < 0.05) at all time intervals. Room-temperature tumescent fluid further enhanced the thermal safety zone without lowering core body temperature. There were no temperature related complications in our study population and no untoward effects of performing temperature measurements. We conclude that there is no clinically significant elevation of subcutaneous temperatures during ultrasound-assisted lipoplasty. Reported ischemic skin complications are more likely the result of injury to the subdermal plexus rather than a temperature-induced thermal injury. Although heat is a natural by-product of the energy transfer involved in ultrasound-assisted lipoplasty, the risk of thermal injury is negligible when the procedure is performed by experienced operators. Complete understanding of the technique along with strict adherence to basic principles of flap vascularity will ensure safe and effective performance of ultrasound-assisted lipoplasty. PMID:9703095

Ablaza, V J; Gingrass, M K; Perry, L C; Fisher, J; Maxwell, G P

1998-08-01

6

Ultrasound properties of liver tissue during heating.  

PubMed

The objective of this work was to determine changes in the ultrasound properties of heated tissues, with potential application to monitoring of minimally invasive thermal therapy (MITT). Changes in backscatter coefficients and frequency-dependent attenuation coefficients were measured over the frequency range 2.5 MHz to 5 MHz from heated samples of store-bought fresh bovine liver, which was used as a tissue model. Individual liver samples were heated from 37 degrees C to either 50 degrees C, 55 degrees C, 60 degrees C, 65 degrees C or 70 degrees C by warm water. The backscatter coefficient increased during the first 3 min by a factor of 1.09 and 1.11 before the tissue reached 50 degrees C and 55 degrees C, respectively. A decrease in backscatter coefficient followed at 50 degrees C by a factor of 1.12 below the initial level and, at 55 degrees C, the backscatter coefficient dropped below the initial level by a factor of 1.19. The backscatter coefficient decreased within the first 2 min by a factor of 1.22 before the tissue reached 60 degrees C, then increased gradually to a factor of 1.05 below the initial level. At 65 degrees C and 70 degrees C, the changes in backscatter coefficient were highly variable, which may have been due to production of gas microbubbles in the heated tissues. The ultrasound attenuation coefficient increased by as much as 1.48 dB cm-1 over a 30-min period at 70 degrees C. First-order rate parameters derived from the attenuation results revealed one rate process at 50 degrees C and 55 degrees C and two rate processes at 60 degrees C, 65 degrees C and 70 degrees C. An activation energy of 1.00 x 10(4) cal mol-1 was derived from the second rate constants at 60 degrees C, 65 degrees C and 70 degrees C, which indicates that changes in attenuation may be due to protein denaturation. In conclusion, ultrasound image monitoring of thermal therapy treatment in liver may be feasible; however, the backscatter coefficient changes during heating are small and are of the same order as the variation in these changes from point to point in the tissue. PMID:9428138

Gertner, M R; Wilson, B C; Sherar, M D

1997-01-01

7

Physics of tissue harmonic imaging by ultrasound  

NASA Astrophysics Data System (ADS)

Tissue Harmonic Imaging (THI) is an imaging modality that is currently deployed on diagnostic ultrasound scanners. In THI the amplitude of the ultrasonic pulse that is used to probe the tissue is large enough that the pulse undergoes nonlinear distortion as it propagates into the tissue. One result of the distortion is that as the pulse propagates energy is shifted from the fundamental frequency of the source pulse into its higher harmonics. These harmonics will scatter off objects in the tissue and images formed from the scattered higher harmonics are considered to have superior quality to the images formed from the fundamental frequency. Processes that have been suggested as possibly responsible for the improved imaging in THI include: (1) reduced sensitivity to reverberation, (2) reduced sensitivity to aberration, and (3) reduction in side lobes. By using a combination of controlled experiments and numerical simulations, these three reasons have been investigated. A single element transducer and a clinical ultrasound scanner with a phased array transducer were used to image a commercial tissue-mimicking phantom with calibrated targets. The higher image quality achieved with THI was quantified in terms of spatial resolution and "clutter" signals. A three-dimensional model of the forward propagation of nonlinear sound beams in media with arbitrary spatial properties (a generalized KZK equation) was developed. A time-domain code for solving the KZK equation was validated with measurements of the acoustic field generated by the single element transducer and the phased array transducer. The code was used to investigate the impact of aberration using tissue-like media with three-dimensional variations in all acoustic properties. The three-dimensional maps of tissue properties were derived from the datasets available through the Visible Female project. The experiments and simulations demonstrated that second harmonic imaging (1) suffers less clutter associated with reverberation; (2) is not immune to aberration effects and (3) suffers less clutter due to reduced side-lobe levels. The results indicate that side lobe suppression is the most significant reason for the improvement of second harmonic imaging.

Jing, Yuan

8

Computer-aided tissue characterization using ultrasound-induced thermal effects: analytical formulation and in-vitro animal study  

NASA Astrophysics Data System (ADS)

Ultrasound radio-frequency (RF) time series analysis provides an effective tissue characterization method to differentiate between healthy and cancerous prostate tissues. In this paper, an analytical model is presented that partially describes the variations in tissue acoustic properties that accompany ultrasound RF time series acquisition procedures. These ultrasound-induced effects, which depend on tissue mechanical and thermophysical properties, are hypothesized to be among the major contributors to the tissue typing capabilities of the RF time series analysis. The model is used to derive two tissue characterization features. The two features are used with a support vector machine classifier to characterize three animal tissue types: chicken breast, bovine liver, and bovine steak. Accuracy values as high as 90% are achieved when the proposed features are employed to differentiate these tissue types. The proposed model may provide a framework to optimize the ultrasound RF time series analysis for future clinical procedures.

Daoud, Mohammad I.; Mousavi, Parvin; Imani, Farhad; Rohling, Robert; Abolmaesumi, Purang

2011-03-01

9

Tissue Bioeffects during Ultrasound-mediated Drug Delivery  

NASA Astrophysics Data System (ADS)

Ultrasound has been developed as both a valuable diagnostic tool and a potent promoter of beneficial tissue bioeffects for the treatment of cardiovascular disease. Vascular effects can be mediated by mechanical oscillations of circulating microbubbles, or ultrasound contrast agents, which may also encapsulate and shield a therapeutic agent in the bloodstream. Oscillating microbubbles can create stresses directly on nearby tissue or induce fluid effects that effect drug penetration into vascular tissue, lyse thrombi, or direct drugs to optimal locations for delivery. These investigations have spurred continued research into alternative therapeutic applications, such as bioactive gas delivery. This dissertation addresses a fundamental hypothesis in biomedical ultrasound: ultrasound-mediated drug delivery is capable of increasing the penetration of drugs across different physiologic barriers within the cardiovascular system, such as the vascular endothelium, blood clots, and smooth muscle cells.

Sutton, Jonathan

10

Drug Delivery to Extravascular Tissue by Ultrasound-activated Microbubbles  

NASA Astrophysics Data System (ADS)

Drugs will be delivered to tissue more efficiently if the vascular endothelial permeability is increased. Although recent studies have established that the permeability of single-cell membranes is increased by ultrasound in combination with contrast agents, it is not known whether this combination can also increase the permeability of an endothelial layer. To investigate endothelial layer permeability, we treated monolayers of human umbilical vein endothelial cells with ultrasound and the contrast agent BR14. Endothelial layer permeability was assessed by measuring the transendothelial electrical resistance (TEER) and the transendothelial transport of fluorescein. Ultrasound in combination with BR14 significantly decreased TEER to 68.0 ± 3.1% of initial values and temporally increased endothelial permeability for fluorescein by 38.1 ± 16.4 %. After treatment, no cell loss or damage was observed. In conclusion, ultrasound in combination with BR14 increased the endothelial layer permeability. This feature may be used for future ultrasound-guided drug delivery systems.

Kooiman, Klazina; Harteveld, Miranda; de Jong, Nico; van Wamel, Annemieke

2007-05-01

11

The thresholds and mechanisms of tissue injury by focused ultrasound  

NASA Astrophysics Data System (ADS)

Therapeutic ultrasound is used in clinics around the world to treat ailments such as uterine fibroids, kidney stones, and plantar fasciitis. While many of the therapeutic effects of ultrasound are elicited by hyperthermia, bubbles can also interact with tissue to produce beneficial effects. For example, bubbles are used in boiling histotripsy to de-bulk tissue and are used in shock wave lithotripsy to break kidney stones. However, the same bubbles that break the kidney stones also damage the kidney, which is why bubble damage is a concern in every ultrasound application including fetal imaging. Whether the aim is to emulsify a tumor or image a fetus, understanding the thresholds and mechanisms of tissue injury by bubbles in an ultrasound field is important for all ultrasound applications and was the goal of this dissertation. One specific application of therapeutic ultrasound, known as boiling histotripsy, uses shock wave heating to explosively expand a millimeter-size boiling bubble at the transducer focus and fractionate bulk tissue. Yet it was unclear how the millimeter-size boiling or vapor bubble broke down the tissue into its submicron components. In this dissertation, we experimentally tested the hypothesis that ultrasonic atomization, or the emission of fine droplets from an acoustically excited liquid film, is the mechanism by which the millimeter-size boiling bubble in boiling histotripsy fractionates tissue into its submicron components. Using high speed photography, we showed that tissue can behave as a liquid such that a miniature acoustic fountain forms and atomization occurs within a millimeter-size cavity that approximates the boiling or vapor bubble produced by boiling histotripsy. The end result of tissue atomization was a hole in the tissue surface. After showing that tissue can be eroded by atomization, a series of experiments were conducted to determine the tissue properties that influence atomization. The results indicated that highly collagenous tissues such as the liver capsule were difficult to atomize; however it was also shown that surface wetting could be used to enhance atomization by changing the focus of the inverted and reflected ultrasound wave. Finally, the role of bubbles in tissue atomization was investigated using a high static pressure chamber, where it was determined that bubbles are necessary for tissue fractionation. While the investigation into the mechanism of boiling histotripsy was the primary focus of this dissertation, we also established thermal and mechanical injury thresholds for renal tissue injury. This work was driven by the need to determine the safety of a specific therapeutic ultrasound application - renal stone repositioning by ultrasonic propulsion - for FDA approval to begin clinical trials. The end result of this dissertation was an increased understanding of how and at what levels bubbles in an ultrasound field can damage tissue, which is important for developing safe and reliable therapies.

Simon, Julianna

12

Ultrasound  

Cancer.gov

Ultrasound uses sound waves with frequencies above those humans can hear. A transducer sends sound waves traveling into the body which are reflected back from organs and tissues, allowing a picture to be made of the internal organs. Ultrasound can show

13

Breast tissue composition and breast density measurements from ultrasound tomography  

NASA Astrophysics Data System (ADS)

It is known that breast cancer risk is greater in women with higher breast densities. Currently, breast density is measured using mammographic percent density, defined as the ratio of fibroglandular to total breast area on a two dimensional mammogram. Alternatively, systems that use ultrasound tomography (UST) create tomographic sound speed images of the patient's breast. These volumetric images can be useful as a diagnostic aid because it is also known that sound speed of tissue is proportional to the density of the tissue. The purpose of this work is to expand on the comparisons of the two imaging modalities by introducing new ultrasound tomography measurements that separate and quantify the fatty and dense tissue distributions within the breast. A total of 249 patients were imaged using both imaging modalities. By using k-means clustering, correlations beyond the volume averaged sound speed of the ultrasound images and the mammographic percent density were investigated. Both the ultrasound and mammographic images were separated into dense and fatty regions. Various associations between the global breast properties as well as separate tissue components were found.

Sak, Mark; Duric, Neb; Boyd, Norman; Littrup, Peter; West, Erik; Li, Cuiping

2012-03-01

14

Incorporating tissue absorption and scattering in rapid ultrasound beam modeling  

NASA Astrophysics Data System (ADS)

We have developed a new approach for modeling the propagation of an ultrasound beam in inhomogeneous tissues such as encountered with high-intensity focused ultrasound (HIFU) for treatment of various diseases. This method, called the hybrid angular spectrum (HAS) approach, alternates propagation steps between the space and the spatial frequency domains throughout the inhomogeneous regions of the body; the use of spatial Fourier transforms makes this technique considerably faster than other modeling approaches (about 10 sec for a 141 x 141 x 121 model). In HIFU thermal treatments, the acoustic absorption property of the tissues is of prime importance since it leads to temperature rise and the achievement of desired thermal dose at the treatment site. We have recently added to the HAS method the capability of independently modeling tissue absorption and scattering, the two components of acoustic attenuation. These additions improve the predictive value of the beam modeling and more accurately describes the thermal conditions expected during a therapeutic ultrasound exposure. Two approaches to explicitly model scattering were developed: one for scattering sizes smaller than a voxel, and one when the scattering scale is several voxels wide. Some anatomically realistic examples that demonstrate the importance of independently modeling absorption and scattering are given, including propagation through the human skull for noninvasive brain therapy and in the human breast for treatment of breast lesions.

Christensen, Douglas; Almquist, Scott

2013-02-01

15

Characterizing Tissue with Acoustic Parameters Derived from Ultrasound Data  

SciTech Connect

In contrast to standard reflection ultrasound (US), transmission US holds the promise of more thorough tissue characterization by generating quantitative acoustic parameters. We compare results from a conventional US scanner with data acquired using an experimental circular scanner operating at frequencies of 0.3 - 1.5 MHz. Data were obtained on phantoms and a normal, formalin-fixed, excised breast. Both reflection and transmission-based algorithms were used to generate images of reflectivity, sound speed and attenuation.. Images of the phantoms demonstrate the ability to detect sub-mm features and quantify acoustic properties such as sound speed and attenuation. The human breast specimen showed full field evaluation, improved penetration and tissue definition. Comparison with conventional US indicates the potential for better margin definition and acoustic characterization of masses, particularly in the complex scattering environments of human breast tissue. The use of morphology, in the context of reflectivity, sound speed and attenuation, for characterizing tissue, is discussed.

Littrup, P; Duric, N; Leach, R R; Azevedo, S G; Candy, J V; Moore, T; Chambers, D H; Mast, J E; Johnson, S A; Holsapple, E

2002-01-23

16

Measurement of Mechanical Properties of Soft Tissue with Ultrasound Vibrometry  

NASA Astrophysics Data System (ADS)

The cardiovascular diseases atherosclerosis, coronary artery disease, hypertension and heart failure have been related to stiffening of vessels and myocardium. Noninvasive measurements of mechanical properties of cardiovascular tissue would facilitate detection and treatment of disease in early stages, thus reducing mortality and possibly reducing cost of treatment. While techniques capable of measuring tissue elasticity have been reported, the knowledge of both elasticity and viscosity is necessary to fully characterize mechanical properties of soft tissues. In this article, we summarize the Shearwave Dispersion Ultrasound Vibrometry (SDUV) method developed by our group and report on advances made in characterizing stiffness of large vessels and myocardium. The method uses radiation forceFadiation force to excite shear waves in soft tissue and pulse echo ultrasound to measure the motion. The speed of propagation of shear waves at different frequencies is used to generate dispersions curves for excised porcine left-ventricular free-wall myocardium and carotid arteries. An antisymmetric Lamb wave model was fitted to the LV myocardium dispersion curves to obtain elasticity and viscosity moduli. The results suggest that the speed of shear wave propagation in four orthogonal directions on the surface of the excised myocardium is similar. These studies show that the SDUV method has potential for clinical application in noninvasive quantification of elasticity and viscosity of vessels and myocardium.

Nenadich, I.; Bernal, M.; Greenleaf, J. F.

17

The tissue effects of ultrasound-assisted lipoplasty.  

PubMed

The objective of our study was to investigate the effects of ultrasonic energy on tissues, using a porcine model, performed under various instrumental and procedural parameters. Domestic pigs were anesthetized and prepared for surgery. An incision was made on the side of the hip randomly assigned to the right or left side. Tumescence solution was infiltrated via a blunt tip, small diameter cannula, followed by performance of standard liposuction. On the contralateral side, a similar incision was made. For ultrasonic liposuction experiments without the sheath, a percutaneous introducer was inserted into the incision, which was protected at the entry site from contact with the cannula. Tumescence solution was infiltrated via a blunt tip, small diameter cannula, and then the site was treated with ultrasonic energy at maximum output from the machine with liposuction concurrent through the hollow cannula. The experiments with the sheath did not require a pretreatment with tumescence solution but consisted of tumescence solution pumped through the sheath at a low infusion rate, with concurrent treatment utilizing ultrasonically assisted liposuction through the central lumen of the cannula. In all cases, the lipoaspirate was preserved for biochemical analysis. After treatment, the pigs were euthanized, and samples for histopathology were taken. The pigs were then perfused with a radio-opaque solution through the left ventricle following preperfusion with saline. The groups were ultrasound-assisted liposuction with sheath (n = 3), ultrasound-assisted without sheath (n = 4), and tumescence alone (n = 1), with standard liposuction performed on the contralateral side for all ultrasound-assisted liposuction animals. The lipoaspirates from the ultrasonically assisted liposuction with the sheath showed significantly less blood loss (measured as hemoglobin in the aspirate) than standard liposuction (p = 0.012) at comparable levels of fat (measured as triglycerides in the aspirate). The lipoaspirates from ultrasound-assisted liposuction without the sheath showed blood loss comparable to that experienced with standard liposuction. The ratio of hemoglobin to triglyceride was lowest in the ultrasound-assisted group with (p = 0.01) and without (p = 0.06) the sheath when compared to traditional liposuction. In both of these treated groups, the radiograms of the perfused areas showed significantly less vascular disruption when compared with suction-assisted liposuction. Histopathologic examination of specimens taken from various treated areas showed substantial tissue damage comparable in ultrasound- and suction-assisted liposuction treated groups. This preliminary experimental study showed that ultrasound-assisted lipoplasty is comparable to traditional suction-assisted lipoplasty. Treatment with ultrasound provided more significant hemoglobin/triglyceride ratios, indicative of more lipid aspirated per hemoglobin lost, and better preservation of vascular tissues as demonstrated by our perfusion studies. Treatment with the sheath showed a significantly lower hemoglobin release with a diminished volume infused into the subcutaneous space during the procedure. PMID:9655430

Kenkel, J M; Robinson, J B; Beran, S J; Tan, J; Howard, B K; Zocchi, M L; Rohrich, R J

1998-07-01

18

Ultrasound-guided tissue fractionation by high intensity focused ultrasound in an in vivo porcine liver model.  

PubMed

The clinical use of high intensity focused ultrasound (HIFU) therapy for noninvasive tissue ablation has been recently gaining momentum. In HIFU, ultrasound energy from an extracorporeal source is focused within the body to ablate tissue at the focus while leaving the surrounding organs and tissues unaffected. Most HIFU therapies are designed to use heating effects resulting from the absorption of ultrasound by tissue to create a thermally coagulated treatment volume. Although this approach is often successful, it has its limitations, such as the heat sink effect caused by the presence of a large blood vessel near the treatment area or heating of the ribs in the transcostal applications. HIFU-induced bubbles provide an alternative means to destroy the target tissue by mechanical disruption or, at its extreme, local fractionation of tissue within the focal region. Here, we demonstrate the feasibility of a recently developed approach to HIFU-induced ultrasound-guided tissue fractionation in an in vivo pig model. In this approach, termed boiling histotripsy, a millimeter-sized boiling bubble is generated by ultrasound and further interacts with the ultrasound field to fractionate porcine liver tissue into subcellular debris without inducing further thermal effects. Tissue selectivity, demonstrated by boiling histotripsy, allows for the treatment of tissue immediately adjacent to major blood vessels and other connective tissue structures. Furthermore, boiling histotripsy would benefit the clinical applications, in which it is important to accelerate resorption or passage of the ablated tissue volume, diminish pressure on the surrounding organs that causes discomfort, or insert openings between tissues. PMID:24843132

Khokhlova, Tatiana D; Wang, Yak-Nam; Simon, Julianna C; Cunitz, Bryan W; Starr, Frank; Paun, Marla; Crum, Lawrence A; Bailey, Michael R; Khokhlova, Vera A

2014-06-01

19

Statistical Parameter Estimation in Ultrasound Backscattering from Tissue Mimicking Media.  

NASA Astrophysics Data System (ADS)

Several tissue characterization parameters, including the effective scatterer number density and the backscatter coefficient, were derived from the statistical properties of ultrasonic echo signals. The effective scatterer number density is the actual scatterer number density in a medium multiplied by a frequency-dependent factor that depends on the differential scattering cross-sections of all scatterers. The method described in this thesis for determining the scatterer number density explicitly retains both the temporal nature of the data acquisition and the properties of the ultrasound field in the data reduction. Moreover, it accounts for the possibility that different sets of scatterers may dominate the echo signal at different frequencies. The random processes involved in forming ultrasound echo signals from random media give rise to an uncertainty in the estimated effective scatterer number density. This uncertainty is evaluated using error propagation. The statistical uncertainty depends on the effective number of scatterers contributing to the segmented echo signal, increasing when the effective number of scatterers increases. Tests of the scatterer number density data reduction method and the statistical uncertainty estimator were done using phantoms with known ultrasound scattering properties. Good agreement was found between measured values and those calculated from first-principles. The properties of the non-Gaussian and non-Rayleigh parameters of ultrasound echo signals are also studied. Both parameters depend on the measurement system, including the transducer field and pulse frequency content, as well as on the medium's properties. The latter is expressed in terms of the scatterer number density and the second and fourth moments of the medium's scattering function. A simple relationship between the non-Gaussian and non-Rayleigh parameters is derived and verified experimentally. Finally, a reference phantom method is proposed for measuring the effective scatterer number density in vivo. Various groups are using the frequency dependent backscatter coefficient (or the spatial autocorrelation function) to characterize scatterer sizes in biological tissue. Generally, sparse scatterer concentrations are assumed in relating scattering parameters to this tissue property. For dense scattering media, we study whether the frequency dependent backscatter coefficient changes with the scatterer volume fraction. Two scattering models suggested by Debye and Yagi are reviewed. In these models, the spatial autocorrelation function describing mass density and compressibility fluctuations in the scattering medium has a characteristic length that depends on the scatterer volume fraction as well as the scatterer size. The models predict the frequency dependence of the backscatter coefficient will vary with the scatterer volume fraction. Qualitative agreement between the model predictions and experimental results are seen for sephadex-in-agar phantoms.

Chen, Jian-Feng

20

Detection of soft tissue foreign bodies by nurse practitioner-performed ultrasound  

PubMed Central

Background This study aimed to evaluate the accuracy of emergency nurse practitioner (NP)-performed point-of-care ultrasound (POCUS) for the detection of soft tissue foreign bodies (FBs). Methods Following a 2-h training session, ten NPs were assessed on their ability to detect various FBs in an experimental model. FBs (wood, metal and plastic) were inserted randomly into eight experimental models (uncooked chicken thighs) by an independent observer. Control experimental models had no FB inserted, but all had a 1-cm incision made on their surface. NPs, blinded to the type of model, were then assessed on their ability to detect the FBs by ultrasound examination using high-frequency linear transducers (Toshiba Nemio). Models were also scanned by two experienced emergency physicians (EPs) as a further control. Results Overall, NP-performed POCUS detected 47 of the 60 foreign bodies with a sensitivity, specificity, positive predictive value and negative predictive value of 78.3%, 50%, 82% and 43%, respectively, compared with 83.3%, 75%, 90.9% and 60% for EPs. Sensitivity for detecting specific types of FB was 95%, 85% and 50% for wood, metal and plastic, respectively, for NP-performed POCUS, compared with 100%, 100% and 50% in the EP group. Conclusions NPs with no previous ultrasound experience can detect soft tissue FBs with accuracy comparable to that of EPs in an experimental model. Test sensitivity was high for wood and metal foreign bodies. Specificity was generally low. PMID:24476553

2014-01-01

21

Probability of cavitation for single ultrasound pulses applied to tissues and tissue-mimicking materials  

PubMed Central

In this article, the negative pressure values at which inertial cavitation consistently occurs in response to a single, 2-cycle, focused ultrasound pulse were measured in several media relevant to cavitation-based ultrasound therapy. The pulse was focused into a chamber containing one of the media, which included liquids, tissue-mimicking materials, and ex-vivo canine tissue. Focal waveforms were measured by two separate techniques using a fiber-optic hydrophone. Inertial cavitation was identified by high-speed photography in optically transparent media and an acoustic passive cavitation detector. The probability of cavitation (Pcav) for a single pulse as a function of peak negative pressure (p?) followed a sigmoid curve, with the probability approaching 1 when the pressure amplitude was sufficient. The statistical threshold (defined as Pcav = 0.5) was between p? = 26.0–30.0 MPa in all samples with a high water content, but varied between p? = 13.7 to > 36 MPa for other media. A model for radial cavitation bubble dynamics was employed to evaluate the behavior of cavitation nuclei at these pressure levels. A single bubble nucleus with an inertial cavitation threshold of p? = 28.2 MPa was estimated to have a 2.5 nm radius in distilled water. These data may be valuable for cavitation-based ultrasound therapy to predict the likelihood of cavitation at different pressure levels and dimensions of cavitation-induced lesions in tissue. PMID:23380152

Maxwell, Adam D.; Cain, Charles A.; Hall, Timothy L.; Fowlkes, J. Brian; Xu, Zhen

2012-01-01

22

Focal testicular lesions: colour Doppler ultrasound, contrast-enhanced ultrasound and tissue elastography as adjuvants to the diagnosis  

PubMed Central

The aim of this review is to illustrate the potential of different and newer ultrasound techniques beyond conventional B-mode imaging, including colour Doppler ultrasound, contrast-enhanced ultrasound (CEUS) and tissue elastography, in the characterisation of both benign and malignant intratesticular lesions. Normally, testicular malignancies, either primary or secondary, demonstrate an increase in colour Doppler signal. However, there is a diversity of benign testicular lesions that may mimic testicular malignancies. The use of CEUS improves characterisation of testicular lesions, and confirms lack of vascularity in benign abnormalities such as epidermoid cysts, infarctions, abscesses and changes following trauma. Tissue elastography allows further evaluation of the cellular consistency of the abnormality. Familiarity with the appearances seen with these ultrasound techniques in both benign and malignant abnormalities should aid in improving confidence in arriving at the correct diagnosis. PMID:22674702

Huang, D Y; Sidhu, P S

2012-01-01

23

Study of ultrasound stiffness imaging methods using tissue mimicking phantoms.  

PubMed

A pilot study was carried out to investigate the performance of ultrasound stiffness imaging methods namely Ultrasound Elastography Imaging (UEI) and Acoustic Radiation Force Impulse (ARFI) Imaging. Specifically their potential for characterizing different classes of solid mass lesions was analyzed using agar based tissue mimicking phantoms. Composite tissue mimicking phantom was prepared with embedded inclusions of varying stiffness from 50 kPa to 450 kPa to represent different stages of cancer. Acoustic properties such as sound speed, attenuation coefficient and acoustic impedance were characterized by pulse echo ultrasound test at 5 MHz frequency and they are ranged from (1564 ± 88 to 1671 ± 124 m/s), (0.6915 ± 0.123 to 0.8268 ± 0.755 db cm(-1)MHz(-1)) and (1.61 × 10(6) ± 0.127 to 1.76 × 10(6) ± 0.045 kg m(-2)s(-1)) respectively. The elastic property Young's Modulus of the prepared samples was measured by conducting quasi static uni axial compression test under a strain rate of 0.5mm/min upto 10 % strain, and the values are from 50 kPa to 450 kPa for a variation of agar concentration from 1.7% to 6.6% by weight. The composite phantoms were imaged by Siemens Acuson S2000 (Siemens, Erlangen, Germany) machine using linear array transducer 9L4 at 8 MHz frequency; strain and displacement images were collected by UEI and ARFI. Shear wave velocity 4.43 ± 0.35 m/s was also measured for high modulus contrast (18 dB) inclusion and X.XX m/s was found for all other inclusions. The images were pre processed and parameters such as Contrast Transfer Efficiency and lateral image profile were computed and reported. The results indicate that both ARFI and UEI represent the abnormalities better than conventional US B mode imaging whereas UEI enhances the underlying modulus contrast into improved strain contrast. The results are corroborated with literature and also with clinical patient images. PMID:24083832

Manickam, Kavitha; Machireddy, Ramasubba Reddy; Seshadri, Suresh

2014-02-01

24

The possibility of detecting magnetic moment generated by ultrasound in polarized tissues  

NASA Astrophysics Data System (ADS)

We propose a method to combine focused ultrasound and electromagnetic field to image the permittivity of biological tissues. It will be shown that magnetic moment can be generated in a polarized tissue by propagating ultrasound. The value of this magnetic moment is proportional to the relative permittivity of the tissue. If the magnetic moment is detectable by a pick-up coil, the described method has the potential for imaging the electrical permittivity of biological tissues. In this paper, we derive the expression for the ultrasound-generated magnetic moment and the voltage in the pick-up coil. We also provide an estimation of the voltage signal.

Xu, Yuan; Renzhiglova, Elena

2010-04-01

25

Window-modulated compounding Nakagami imaging for ultrasound tissue characterization.  

PubMed

Ultrasound Nakagami parametric imaging is a useful tool for tissue characterization. Previous literature has suggested using a square with side lengths corresponding to 3 times the transducer pulse length as the minimum window for constructing the Nakagami image. This criterion does not produce sufficiently smooth images for the Nakagami image to characterize homogeneous tissues. To improve image smoothness, we proposed window-modulated compounding (WMC) Nakagami imaging based on summing and averaging the Nakagami images formed using sliding windows with varying window side lengths from 1 to N times the transducer pulse length in 1 pulse length step. Simulations (the number densities of scatterers: 2-16 scatterers/mm(2)) and experiments on fully developed speckle phantoms (the scatterer diameters: 20-106 ?m) were conducted to suggest an appropriate number of frames N and to evaluate the image smoothness and resolution by analyzing the full width at half maximum (FWHM) of the parameter distribution and the widths of the image autocorrelation function (ACF), respectively. In vivo ultrasound measurements on rat livers without and with cirrhosis were performed to validate the practical performance of the WMC Nakagami image in tissue characterization. The simulation results showed that using a range of N from 7 to 10 as the number of frames for image compounding reduces the estimation error to less than 5%. Based on this criterion, the Nakagami parameter obtained from the WMC Nakagami image increased from 0.45 to 0.95 after increasing the number densities of scatterers from 2 to 16 scatterers/mm(2). The FWHM of the parameter distribution (bins=40) was 13.5±1.4 for the Nakagami image and 9.1±1.43 for the WMC Nakagami image, respectively (p-value<.05). The widths of the ACF for the Nakagami and WMC Nakagami images were 454±5.36 and 458±4.33, respectively (p-value>.05). In the phantom experiments, we also found that the FWHM of the parameter distribution for the WMC Nakagami image was smaller than that of the conventional Nakagami image (p-value<.05), and there was no significant difference of the ACF width between the Nakagami and WMC Nakagami images (p-value>.05). In the animal experiments, the Nakagami parameters obtained from the WMC Nakagami image for normal and cirrhotic rat livers were 0.62±0.08 and 0.92±0.07, respectively (p-value<.05). The results demonstrated that the WMC technique significantly improved the image smoothness of Nakagami imaging without resolution degradation, giving Nakagami model-based imaging the ability to visualize scatterer properties with enhanced image quality. PMID:24835004

Tsui, Po-Hsiang; Ma, Hsiang-Yang; Zhou, Zhuhuang; Ho, Ming-Chih; Lee, Yu-Hsin

2014-08-01

26

Intense focused ultrasound preferentially stimulates subcutaneous and focal neuropathic tissue: preliminary results  

PubMed Central

Objective Potential peripheral sources of pain from subcutaneous tissue can require invasive evocative tests for their localization and assessment. Here we describe studies whose ultimate goal is development of a non-invasive evocative test for subcutaneous, painful tissue. Design We used a rat model of a focal and subcutaneous neuroma to test the hypothesis that intense focused ultrasound can differentiate focal and subcutaneous neuropathic tissue from control tissue. To do so we first applied intense focused ultrasound (2 MHz, with individual pulses of 0.1 seconds in duration) to the rat’s neuroma while the rat was under light anesthesia. We started with low values of intensity which we increased until intense focused ultrasound stimulation caused the rat to reliably flick its paw. We then applied that same intense focused ultrasound protocol to control tissue away from the neuroma and assayed for the rat’s response to that stimulation. Results Intense focused ultrasound of sufficient strength (I_sata of 600 +/? 160 W/cm^2) applied to the neuroma caused the rat to flick its paw, while the same intense focused ultrasound applied millimeters to a centimeter away failed to induce a paw flick. Conclusion Successful stimulation of the neuroma by intense focused ultrasound required co-localization of the neuroma and intense focused ultrasound, supporting our hypothesis. PMID:23137045

McClintic, Abbi M.; Dickey, Trevor C.; Gofeld, Michael; Kliot, Michel; Loeser, John D.; Richebe, Philippe; Mourad, Pierre D.

2012-01-01

27

A Study of Cavitation Activity in Ex vivo Tissue Exposed to High Intensity Focused Ultrasound  

NASA Astrophysics Data System (ADS)

Cavitation is often avoided in Focused Ultrasound Surgery (FUS or HIFU) because it can render lesion formation unpredictable. However, cavitation is known to enhance heating. Emissions used as indicators for cavitation activity in ex vivo tissue are not fully understood. This study investigates a wide range of simultaneous acoustic emissions and other potential indicators of cavitation activity. A high frequency (?50MHz) data acquisition system is used to detect cavitation ex vivo. The passive cavitation detector (PCD) used is a broadband (0.1-10MHz) cavitation sensor. Its broadband nature allows simultaneous measurement of subharmonics, superharmonics and broadband emissions, all potential indicators of either inertial or both types of cavitation. The electrical impedance change of the transducer (1.69MHz, 15cm focal length, 1.79f-number), caused by backscattered ultrasound, has been monitored. Low frequency acoustic signals (<100kHz) have been recorded using a hydrophone (Reson TC4013, 1Hz-170kHz). The ultimate aim of this work is to investigate the possibility of detecting cavitation signals from HIFU during clinical treatments. Results of monitoring multiple cavitation signals during ex vivo HIFU exposure are presented. The relationship between impedance change and superharmonic emissions, indicating discrete acoustic emissions or scattering of ultrasound from bubbles, are discussed. Artefacts in B-mode ultrasound scans taken during HIFU exposures have been seen to correlate with impedance change and acoustic emissions. This is still under investigation. Cavitation thresholds in degassed water and ex vivo tissue have been investigated. This work paves the way for investigation of the enhancement of lesion formation from HIFU exposures by exploiting cavitation activity.

McLaughlan, James; Rivens, Ian; ter Haar, Gail

2007-05-01

28

Design of an optimum ultrasound pattern to minimize multiple-scattered light reflected from inhomogeneous tissue  

NASA Astrophysics Data System (ADS)

Pressure changes caused by an ultrasound pattern inside tissue will modify its density and hence its refractive index. We present an integrated computational imaging approach to minimize multiple-scattered reflected light from tissue. It is based on optimum modulation of the refractive index of tissue using an ultrasound pattern. We examine issues related the design of such pattern using COMSOL Multiphysics. An optimum ultrasound pattern could be used to design and implement an integrated- computational optical coherence tomography (IC-OCT) system with extended depth of imaging.

Pereira, Pedro F.; Sherif, Sherif S.

2012-02-01

29

Is therapeutic ultrasound effective in treating soft tissue lesions?  

PubMed Central

Of 76 patients with lateral epicondylitis, 38 were randomly allocated to receive ultrasound treatment and 38 placebo. All 76 were given 12 treatments each over four to six weeks. The conditions of 24 patients (63%) treated with ultrasound and 11 (29%) given placebo improved, the difference being significant at the 1% level. Improvement in particular clinical variables (pain score, weight lifting, grip strength) also showed an advantage for the patients given ultrasound treatment. A simple underwater radiation balance showed considerable fluctuation in ultrasonic output, and frequent checks of output were shown to be necessary. Ultrasound enhances recovery in most patients with lateral epicondylitis. PMID:3918652

Binder, A; Hodge, G; Greenwood, A M; Hazleman, B L; Page Thomas, D P

1985-01-01

30

Is therapeutic ultrasound effective in treating soft tissue lesions?  

PubMed

Of 76 patients with lateral epicondylitis, 38 were randomly allocated to receive ultrasound treatment and 38 placebo. All 76 were given 12 treatments each over four to six weeks. The conditions of 24 patients (63%) treated with ultrasound and 11 (29%) given placebo improved, the difference being significant at the 1% level. Improvement in particular clinical variables (pain score, weight lifting, grip strength) also showed an advantage for the patients given ultrasound treatment. A simple underwater radiation balance showed considerable fluctuation in ultrasonic output, and frequent checks of output were shown to be necessary. Ultrasound enhances recovery in most patients with lateral epicondylitis. PMID:3918652

Binder, A; Hodge, G; Greenwood, A M; Hazleman, B L; Page Thomas, D P

1985-02-16

31

Bulk ablation of soft tissue with intense ultrasound: Modeling and experiments  

E-print Network

. INTRODUCTION Thermal ablation using intense ultrasound is a therapy with potential utility for treatment, Ohio 45242 Peter G. Barthe and Michael H. Slayton Guided Therapy Systems, 33 S. Sycamore St., Mesa ablation of soft tissue using intense ultrasound, with potential applications in the thermal treatment

Mast, T. Douglas

32

Optical and acoustic monitoring of bubble cloud dynamics at a tissue-fluid interface in ultrasound tissue erosion  

PubMed Central

Short, high-intensity ultrasound pulses have the ability to achieve localized, clearly demarcated erosion in soft tissue at a tissue-fluid interface. The primary mechanism for ultrasound tissue erosion is believed to be acoustic cavitation. To monitor the cavitating bubble cloud generated at a tissue-fluid interface, an optical attenuation method was used to record the intensity loss of transmitted light through bubbles. Optical attenuation was only detected when a bubble cloud was seen using high speed imaging. The light attenuation signals correlated well with a temporally changing acoustic backscatter which is an excellent indicator for tissue erosion. This correlation provides additional evidence that the cavitating bubble cloud is essential for ultrasound tissue erosion. The bubble cloud collapse cycle and bubble dissolution time were studied using the optical attenuation signals. The collapse cycle of the bubble cloud generated by a high intensity ultrasound pulse of 4–14 ?s was ~40–300 ?s depending on the acoustic parameters. The dissolution time of the residual bubbles was tens of ms long. This study of bubble dynamics may provide further insight into previous ultrasound tissue erosion results. PMID:17471753

Xu, Zhen; Hall, Timothy L.; Fowlkes, J. Brian; Cain, Charles A.

2009-01-01

33

Is therapeutic ultrasound effective in treating soft tissue lesions?  

Microsoft Academic Search

Of 76 patients with lateral epicondylitis, 38 were randomly allocated to receive ultrasound treatment and 38 placebo. All 76 were given 12 treatments each over four to six weeks. The conditions of 24 patients (63%) treated with ultrasound and 11 (29%) given placebo improved, the difference being significant at the 1% level. Improvement in particular clinical variables (pain score, weight

A Binder; G Hodge; A M Greenwood; B L Hazleman; D P Page Thomas

1985-01-01

34

Multispectral photoacoustic imaging of tissue denaturation induced by high-intensity focused ultrasound treatment  

NASA Astrophysics Data System (ADS)

This paper presents an ex vivo study in imaging high-intensity focused ultrasound induced tissue denaturation with multispectral photoacoustic approach. Beef tissues treated by both water bath and high-intensity focused ultrasound were imaged and evaluated by photoacoustic imaging method, where light in multiple optical wavelengths between 700nm and 900nm is applied. Tissue denaturation after being treated by water bath and high-intensity focused ultrasound has been observed in multispectral photoacoustic images. The denaturation is more striking in relatively shorter optical wavelength photoacoustic images than in relatively longer optical wavelength photoacoustic images. This study suggests that multispectral photoacoustic imaging method is promising in the evaluation of tissue denaturation induced by high- intensity focused ultrasound treatment.

Sun, Yao; Li, King C. P.; O'Neill, Brian

2013-03-01

35

Validity and reliability of an ultrasound system for estimating adipose tissue.  

PubMed

When health professionals measure the fitness levels of clients, body composition is usually estimated. In field settings, body composition is commonly estimated with skinfolds or bioelectrical impedance analysis. Recently, a portable ultrasound device has been manufactured to estimate what percentage of body mass is composed of adipose tissue (AT%). A reported advantage of using ultrasound is that inter- and intrarater variations may be minimized when compared with the skinfold technique. Therefore, the purpose of this pilot study was twofold; 1) to determine the validity of a portable ultrasound device compared with skinfolds and 2) determine the reliability of the portable ultrasound device. Participants had their measurements taken in the following order: urine specific gravity, body mass, height, skinfolds and ultrasound determined. Participants had their urine specific gravity and ultrasound determined AT% estimates measured again 48 h later. The current pilot study found that the ultrasound was not a valid estimate of AT% when compared with the skinfold estimate (TE > 4%). In addition, the 1-site estimate from the ultrasound was more reliable than the 3-site estimate of AT%. These data are of importance to practitioners because it demonstrates that while the ultrasound is not a valid estimate compared with skinfolds, the 1-site estimate may be able to track changes in AT% over time, making the ultrasound an option for assessing changes in body composition. PMID:23879395

Loenneke, Jeremy P; Barnes, Jeremy T; Wagganer, Jason D; Wilson, Jacob M; Lowery, Ryan P; Green, Cody E; Pujol, Thomas J

2014-03-01

36

Ultrasound-modulated optical tomography in soft biological tissues  

E-print Network

. However, due to the diffusion of light, it is dificult to achieve simultaneously both good spatial resolution and good imaging depth with the pure optical imaging modalities. This work focuses on the ultrasound-modulated optical tomography - a hybrid...

Sakadzic, Sava

2007-09-17

37

Towards 3D ultrasound image based soft tissue tracking: a transrectal ultrasound prostate image alignment system.  

PubMed

The emergence of real-time 3D ultrasound (US) makes it possible to consider image-based tracking of subcutaneous soft tissue targets for computer guided diagnosis and therapy. We propose a 3D transrectal US based tracking system for precise prostate biopsy sample localisation. The aim is to improve sample distribution, to enable targeting of unsampled regions for repeated biopsies, and to make post-interventional quality controls possible. Since the patient is not immobilized, since the prostate is mobile and due to the fact that probe movements are only constrained by the rectum during biopsy acquisition, the tracking system must be able to estimate rigid transformations that are beyond the capture range of common image similarity measures. We propose a fast and robust multi-resolution attribute-vector registration approach that combines global and local optimization methods to solve this problem. Global optimization is performed on a probe movement model that reduces the dimensionality of the search space and thus renders optimization efficient. The method was tested on 237 prostate volumes acquired from 14 different patients for 3D to 3D and 3D to orthogonal 2D slices registration. The 3D-3D version of the algorithm converged correctly in 96.7% of all cases in 6.5s with an accuracy of 1.41mm (r.m.s.) and 3.84mm (max). The 3D to slices method yielded a success rate of 88.9% in 2.3s with an accuracy of 1.37mm (r.m.s.) and 4.3mm (max). PMID:18044549

Baumann, Michael; Mozer, Pierre; Daanen, Vincent; Troccaz, Jocelyne

2007-01-01

38

Histological and Ultrastructural Effects of Ultrasound-induced Cavitation on Human Skin Adipose Tissue  

PubMed Central

Background: In aesthetic medicine, the most promising techniques for noninvasive body sculpturing purposes are based on ultrasound-induced fat cavitation. Liporeductive ultrasound devices afford clinically relevant subcutaneous fat pad reduction without significant adverse reactions. This study aims at evaluating the histological and ultrastructural changes induced by ultrasound cavitation on the different cell components of human skin. Methods: Control and ultrasound-treated ex vivo abdominal full-thickness skin samples and skin biopsies from patients pretreated with or without ultrasound cavitation were studied histologically, morphometrically, and ultrastructurally to evaluate possible changes in adipocyte size and morphology. Adipocyte apoptosis and triglyceride release were also assayed. Clinical evaluation of the effects of 4 weekly ultrasound vs sham treatments was performed by plicometry. Results: Compared with the sham-treated control samples, ultrasound cavitation induced a statistically significant reduction in the size of the adipocytes (P < 0.001), the appearance of micropores and triglyceride leakage and release in the conditioned medium (P < 0.05 at 15 min), or adipose tissue interstitium, without appreciable changes in microvascular, stromal, and epidermal components and in the number of apoptotic adipocytes. Clinically, the ultrasound treatment caused a significant reduction of abdominal fat. Conclusions: This study further strengthens the current notion that noninvasive transcutaneous ultrasound cavitation is a promising and safe technology for localized reduction of fat and provides experimental evidence for its specific mechanism of action on the adipocytes.

Li, Alessandro Quattrini; Freschi, Giancarlo; Russo, Giulia Lo

2013-01-01

39

Transient temperature rise due to ultrasound absorption at a bone/soft-tissue interface  

NASA Astrophysics Data System (ADS)

Thermal effects due to high ultrasound absorption in bone pose an ongoing safety issue. Of considerable concern is the heating of the soft tissue adjacent to the bone surface. Mathematical models can be useful in predicting the transient temperature near the interface during insonation. This paper develops a model that provides the temperature field in terms of simple expressions that convey the functional dependence of the material properties, and are easily incorporated into standards and ultrasound machine software, yet are able to incorporate the material properties of both bone and soft tissue. The model contains an asymptotic theory based upon a ``high-attenuation'' assumption: the distance diffused by heat over the time of interest is large compared to the ultrasound attenuation length. Model predictions of temperature rise and location of maximum temperature were in close agreement with finite-element calculations, using parameters appropriate for radiation-force imaging and focused-ultrasound surgery.

Myers, Matthew R.

2004-06-01

40

Acoustically accessible window determination for ultrasound mediated treatment of glycogen storage disease type Ia patients  

NASA Astrophysics Data System (ADS)

Glycogen storage disease type Ia (GSDIa) is caused by an inherited single-gene defect resulting in an impaired glycogen to glucose conversion pathway. Targeted ultrasound mediated delivery (USMD) of plasmid DNA (pDNA) to liver in conjunction with microbubbles may provide a potential treatment for GSDIa patients. As the success of USMD treatments is largely dependent on the accessibility of the targeted tissue by the focused ultrasound beam, this study presents a quantitative approach to determine the acoustically accessible liver volume in GSDIa patients. Models of focused ultrasound beam profiles for transducers of varying aperture and focal lengths were applied to abdomen models reconstructed from suitable CT and MRI images. Transducer manipulations (simulating USMD treatment procedures) were implemented via transducer translations and rotations with the intent of targeting and exposing the entire liver to ultrasound. Results indicate that acoustically accessible liver volumes can be as large as 50% of the entire liver volume for GSDIa patients and on average 3 times larger compared to a healthy adult group due to GSDIa patients' increased liver size. Detailed descriptions of the evaluation algorithm, transducer-and abdomen models are presented, together with implications for USMD treatments of GSDIa patients and transducer designs for USMD applications.

Wang, Shutao; Raju, Balasundar I.; Leyvi, Evgeniy; Weinstein, David A.; Seip, Ralf

2012-10-01

41

An expectation maximization framework for an improved ultrasound-based tissue characterization  

NASA Astrophysics Data System (ADS)

Ultrasonic tissue characterization has been gaining increasing attention. This procedure is generally based on the analysis of the echo signal. As the ultrasound echo is degraded by the system Point Spread Function, deconvolution could be employed to provide a tissue response estimate, exploitable for a better characterization. In this context, we present a deconvolution framework expressively designed to improve tissue characterization. Thanks to a new model for tissue reflectivity the proposed framework overcomes limitations associated with standard ones. The performance was evaluated from several tissue-mimicking phantoms. Obtained results show relevant improvements in classification accuracy. From a comparison with standard schemes the superiority of the proposed algorithm was attested.

Alessandrini, Martino; Maggio, Simona; Porée, Jonathan; De Marchi, Luca; Speciale, Nicolò; Franceschini, Emilie; Bernard, Olivier; Basset, Olivier

2011-03-01

42

Model-based correction of tissue compression for tracked ultrasound in soft tissue image-guided surgery.  

PubMed

Acquisition of ultrasound data negatively affects image registration accuracy during image-guided therapy because of tissue compression by the probe. We present a novel compression correction method that models sub-surface tissue displacement resulting from application of a tracked probe to the tissue surface. Patient landmarks are first used to register the probe pose to pre-operative imaging. The ultrasound probe geometry is used to provide boundary conditions to a biomechanical model of the tissue. The deformation field solution of the model is inverted to non-rigidly transform the ultrasound images to an estimation of the tissue geometry before compression. Experimental results with gel phantoms indicated that the proposed method reduced the tumor margin modified Hausdorff distance (MHD) from 5.0 ± 1.6 to 1.9 ± 0.6 mm, and reduced tumor centroid alignment error from 7.6 ± 2.6 to 2.0 ± 0.9 mm. The method was applied to a clinical case and reduced the tumor margin MHD error from 5.4 ± 0.1 to 2.6 ± 0.1 mm and the centroid alignment error from 7.2 ± 0.2 to 3.5 ± 0.4 mm. PMID:24412172

Pheiffer, Thomas S; Thompson, Reid C; Rucker, Daniel C; Simpson, Amber L; Miga, Michael I

2014-04-01

43

Ultrasound Technologies for the Spatial Patterning of Cells and Extracellular Matrix Proteins and the Vascularization of Engineered Tissue  

NASA Astrophysics Data System (ADS)

Technological advancements in the field of tissue engineering could save the lives of thousands of organ transplant patients who die each year while waiting for donor organs. Currently, two of the primary challenges preventing tissue engineers from developing functional replacement tissues and organs are the need to recreate complex cell and extracellular microenvironments and to vascularize the tissue to maintain cell viability and function. Ultrasound is a form of mechanical energy that can noninvasively and nondestructively interact with tissues at the cell and protein level. In this thesis, novel ultrasound-based technologies were developed for the spatial patterning of cells and extracellular matrix proteins and the vascularization of three-dimensional engineered tissue constructs. Acoustic radiation forces associated with ultrasound standing wave fields were utilized to noninvasively control the spatial organization of cells and cell-bound extracellular matrix proteins within collagen-based engineered tissue. Additionally, ultrasound induced thermal mechanisms were exploited to site-specifically pattern various extracellular matrix collagen microstructures within a single engineered tissue construct. Finally, ultrasound standing wave field technology was used to promote the rapid and extensive vascularization of three-dimensional tissue constructs. As such, the ultrasound technologies developed in these studies have the potential to provide the field of tissue engineering with novel strategies to spatially pattern cells and extracellular matrix components and to vascularize engineered tissue, and thus, could advance the fabrication of functional replacement tissues and organs in the field of tissue engineering.

Garvin, Kelley A.

44

Quasi-static elastography and its application in investigation of focused ultrasound induced tissue lesions  

NASA Astrophysics Data System (ADS)

Monitoring of Focused Ultrasound (FUS) therapy has always been a key factor for a successful therapy. Although B-mode ultrasound has long been used for monitoring FUS therapy, the gray scale changes can not precisely reflect the lesion formation inside the tissue, while MR thermometry is considered to be too expensive. In this study, elastography had been performed using a commercial ultrasound system to investigate lesions produced by FUS irradiation in vitro. Several motion detection algorithms had been performed to improve the motion detection accuracy in the elastography. The effects of different algorithms on the motion detection accuracy were compared. Experimental results on the FUS induced lesion in swine muscle were introduced. The results indicated that lesions induced by small dosage of FUS inside the tissue can be successfully detected, which has a profound clinical meaning for the monitoring of FUS therapy.

Wang, Bin; Ling, Tao; Shen, Yong; Wang, Yan; Zheng, Hairong; Li, Faqi

2012-10-01

45

Real-time tissue tracking with B-mode ultrasound using speckle and visual servoing.  

PubMed

We present a method for real-time tracking of moving soft tissue with B-mode ultrasound (US). The method makes use of the speckle information contained in the US images to estimate the in-plane and out-of-plane motion of a fixed target relative to the ultrasound scan plane. The motion information is then used as closed-loop feedback to a robot which corrects for the target motion. The concept is demonstrated for translation motions in an experimental setup consisting of an ultrasound speckle phantom, a robot for simulating tissue motion, and a robot that performs motion stabilization from US images. This concept shows promise for US-guided procedures that require real-time motion tracking and compensation. PMID:18044546

Krupa, Alexandre; Fichtinger, Gabor; Hager, Gregory D

2007-01-01

46

Ultrasound and Doppler US in Evaluation of Superficial Soft-tissue Lesions  

PubMed Central

Improved developments in digital ultrasound technology and the use of high-frequency broadband transducers make ultrasound (US) imaging the first screening tool in investigating superficial tissue lesions. US is a safe (no ionizing radiation), portable, easily repeatable, and cheap form of imaging compared to other imaging modalities. US is an excellent imaging modality to determine the nature of a mass lesion (cystic or solid) and its anatomic relation to adjoining structures. Masses can be characterized in terms of their size, number, component, and vascularity with US and Doppler US especially with power Doppler US. US, however, is operator dependent and has a number of artifacts that can result in misinterpretation. In this review, we emphasize the role of ultrasound, particularly power Doppler, in superficial soft-tissue lesions. PMID:24744969

Toprak, Huseyin; Kilic, Erkan; Serter, Asli; Kocakoc, Ercan; Ozgocmen, Salih

2014-01-01

47

Fine-Needle Biopsy: Should This Be the First Choice in Endoscopic Ultrasound-Guided Tissue Acquisition?  

PubMed Central

Endoscopic ultrasound (EUS)-guided tissue acquisition is an indispensable technique for the diagnosis of many diseases of the gastrointestinal tract and adjacent structures. EUS-guided fine-needle aspiration (EUS-FNA) is known for its high accuracy and low complication rate. However, the outcome of EUS-FNA highly depends on several factors such as the location and characteristics of the lesion, endosonographer's experience, technique of sampling and sample preparation, type and size of the needle used, and presence of a cytopathologist for rapid on-site examination. EUS-guided fine-needle biopsy is useful to obtain core tissue samples with relatively fewer passes. Aspiration of core tissue with preserved architecture is beneficial for the diagnosis of certain diseases and the performance of ancillary testing such as tumor molecular profiling. Issues related to needle size, type, and their acquired samples for cytologic and histologic evaluation are discussed here. PMID:25325002

2014-01-01

48

Temperature dependence of the shear modulus of soft tissues assessed by ultrasound  

Microsoft Academic Search

Ultrasound-based techniques to monitor HIFU treatments, combining temperature and elasticity mapping, require better understanding of the thermal effects on soft tissues elasticity. Hence, the study aims to evaluate the temperature dependence of the shear modulus of bovine muscles. Nine ex vivo samples of bovine muscle were slowly heated into a thermally-controlled saline bath. Thermocouples were used to assess temperatures into

E. Sapin; J.-L. Gennisson; M. Pernot; M. Fink; M. Tanter

2009-01-01

49

Ultrasound-modulated optical tomography of biological tissue by use of contrast of laser speckles  

Microsoft Academic Search

Ultrasound-modulated optical tomography based on the measurement of laser-speckle contrast was investigated. An ultrasonic beam was focused into a biological-tissue sample to modulate the laser light passing through the ultrasonic column inside the tissue. The contrast of the speckle pattern formed by the transmitted light was found to depend on the ultrasonic modulation and could be used for imaging. Variation

Jun Li; Geng Ku; Lihong V. Wang

2002-01-01

50

Mechanical Model Analysis for Quantitative Evaluation of Liver Fibrosis Based on Ultrasound Tissue Elasticity Imaging  

NASA Astrophysics Data System (ADS)

Precise evaluation of the stage of chronic hepatitis C with respect to fibrosis has become an important issue to prevent the occurrence of cirrhosis and to initiate appropriate therapeutic intervention such as viral eradication using interferon. Ultrasound tissue elasticity imaging, i.e., elastography can visualize tissue hardness/softness, and its clinical usefulness has been studied to detect and evaluate tumors. We have recently reported that the texture of elasticity image changes as fibrosis progresses. To evaluate fibrosis progression quantitatively on the basis of ultrasound tissue elasticity imaging, we introduced a mechanical model of fibrosis progression and simulated the process by which hepatic fibrosis affects elasticity images and compared the results with those clinical data analysis. As a result, it was confirmed that even in diffuse diseases like chronic hepatitis, the patterns of elasticity images are related to fibrous structural changes caused by hepatic disease and can be used to derive features for quantitative evaluation of fibrosis stage.

Shiina, Tsuyoshi; Maki, Tomonori; Yamakawa, Makoto; Mitake, Tsuyoshi; Kudo, Masatoshi; Fujimoto, Kenji

2012-07-01

51

Direct In Vivo Visualization of Intravascular Destruction of Microbubbles by Ultrasound and its Local Effects on Tissue  

Microsoft Academic Search

Background—Our aim was to observe ultrasound-induced intravascular microbubble destruction in vivo and to characterize any resultant bioeffects. Methods and Results—Intravital microscopy was used to visualize the spinotrapezius muscle in 15 rats during ultrasound delivery. Microbubble destruction during ultrasound exposure caused rupture of #7-mm microvessels (mostly capillaries) and the production of nonviable cells in adjacent tissue. The number of microvessels ruptured

Danny M. Skyba; Richard J. Price; Andre Z. Linka; Thomas C. Skalak; Sanjiv Kaul

2010-01-01

52

Ultrasound phase-contrast transmission imaging of localized thermal variation in a breast tissue model  

NASA Astrophysics Data System (ADS)

The present numeric study examines an ultrasound phase contrast method for imaging localized temperature rises in tissue, such as heating experienced in thermal ablation treatments. We tested the method's ability to produce thermal images by simulating the signal from a planar ultrasound source directed through tissue containing skin, fat, and muscle layers. Phase-contrast imaging only requires phase shifts a fraction of a wavelength for detection, thus we tested for the feasibility of imaging at low (submegahertz) frequencies, allowing greater depth penetration and reduced scattering away from the image plane. The tradeoff for lower frequencies was a reduced spatial resolution. It was therefore necessary to determine the lowest possible frequency that could still provide information about the tissue structure and information about the temperature rise in the heated volume. After studying a tomographically reconstructed 4-mm cylindrical heated region in a 100-mm-thick section breast tissue model, thermal effects were detected at frequencies as low as 0.4 MHz, which allowed reconstruction resolution of about 2 mm2 over the image plane. This method may have applications for example in controlling focused ultrasound surgery of breast.

Clement, Greg; Hynynen, Kullervo

2003-04-01

53

3-d ultrasound-guided robotic needle steering in biological tissue.  

PubMed

Robotic needle steering systems have the potential to greatly improve medical interventions, but they require new methods for medical image guidance. Three-dimensional (3-D) ultrasound is a widely available, low-cost imaging modality that may be used to provide real-time feedback to needle steering robots. Unfortunately, the poor visibility of steerable needles in standard grayscale ultrasound makes automatic segmentation of the needles impractical. A new imaging approach is proposed, in which high-frequency vibration of a steerable needle makes it visible in ultrasound Doppler images. Experiments demonstrate that segmentation from this Doppler data is accurate to within 1-2 mm. An image-guided control algorithm that incorporates the segmentation data as feedback is also described. In experimental tests in ex vivo bovine liver tissue, a robotic needle steering system implementing this control scheme was able to consistently steer a needle tip to a simulated target with an average error of 1.57 mm. Implementation of 3-D ultrasound-guided needle steering in biological tissue represents a significant step toward the clinical application of robotic needle steering. PMID:25014948

Adebar, Troy K; Fletcher, Ashley E; Okamura, Allison M

2014-12-01

54

Noninvasive surgery of prostate tissue by high-intensity focused ultrasound: an updated report  

NASA Astrophysics Data System (ADS)

High Intensity Focused Ultrasound (HIFU) has been clinically used for the treatment of benign prostatic hyperplasia (BPH) and it is experimentally applied for the treatment of localized prostate caner (PC). Recent advances in the transducer material and technology have permitted to combine the ultrasound visualization capability and HIFU on the same ceramic crystal. Also, the transducer efficiency has increased to a level that a smaller size intracavity probe can be made to produce sufficient acoustic power required for the focused ultrasound surgery of the prostate. Using this technology, 4 MHz mechanically scanning transrectal ultrasound probes has been designed. The transrectal probes are used with Sonablate (SB-200, manufactured by Focus Surgery, Inc., Indianapolis, IN) device. The SB-200 produces both transverse and longitudinal images of the prostate. The transverse and longitudinal images are used for selection of tissue volume, treatment planning and monitoring of tissue during the HIFU treatment cycle. The paper reviews the present operation of the device and recent clinical protocol that has improved efficiency, efficacy and safety of the device. The two years follow-up clinical results from the multi-site US Pilot Study (USPS) and The Male Health Centre are compared with the Kitasato-study (Kitasato School of Medicine, Sagamihara, Japan).

Sanghvi, Narendra T.; Syrus, J.; Foster, Richard S.; Bihrle, Richard; Casey, Richard W.; Uchida, Toyoak

2000-05-01

55

EGFP gene transfection into the synovial joint tissues of rats with rheumatoid arthritis by ultrasound-mediated microbubble destruction  

PubMed Central

The aim of the present study was to explore the feasibility of enhancing green fluorescent protein (EGFP) gene transfection into the synovial joint tissues of rats with rheumatoid arthritis (RA) by ultrasound-mediated microbubble destruction. An optimal SonoVue dose was determined using 40 normal rats categorized into five groups according to the various doses of microbubbles used. At 1 week after ultrasound irradiation, the rats were sacrificed. Damage to the joint synovial tissues was observed with hematoxylin and eosin histopathological staining under a microscope. A further 44 normal rats were used to establish a rat model of RA, and were then categorized into four groups: EGFP, ultrasound + EGFP, microbubbles + EGFP and ultrasound + microbubbles + EGFP. The last group was irradiated with ultrasound for 10 min following the injection of 300 ?l SonoVue and 10 ?g EGFP into the joint cavity. Rats were sacrificed after 3 days and synovial tissue was collected from the knee joints for observation of EGFP with fluorescence microscopy and analysis by quantitative polymerase chain reaction. EGFP expression was observed in the synovial tissues of all groups. However, high EGFP expression levels were observed in the ultrasound + microbubbles + EGFP group. No statistically significant differences (P>0.05) were observed in the EGFP expression levels between the EGFP, ultrasound + EGFP and microbubbles + EGFP groups. However, EGFP expression levels in the EGFP, ultrasound + EGFP and microbubbles + EGFP groups significantly differed (P<0.05) from that in the ultrasound + microbubbles + EGFP group. Therefore, ultrasound-mediated microbubble destruction improved EGFP transfection efficiency into the joint synovial tissues of rats with RA. PMID:24940446

JING, XIANG-XIANG; LIU, JIE; YANG, BING-ANG; FU, SHAO-QING; WU, TANG-NA; WANG, DONG-LIN

2014-01-01

56

High-resolution vascular tissue characterization in mice using 55 MHz ultrasound hybrid imaging  

PubMed Central

Ultrasound and Duplex ultrasonography in particular are routinely used to diagnose cardiovascular disease (CVD), which is the leading cause of morbidity and mortality worldwide. However, these techniques may not be able to characterize vascular tissue compositional changes due to CVD. This work describes an ultrasound-based hybrid imaging technique that can be used for vascular tissue characterization and the diagnosis of atherosclerosis. Ultrasound radiofrequency (RF) data were acquired and processed in time, frequency, and wavelet domains to extract six parameters including time integrated backscatter (TIB), time variance (Tvar), time entropy (TE), frequency integrated backscatter (FIB), wavelet root mean square value (Wrms), and wavelet integrated backscatter (WIB). Each parameter was used to reconstruct an image co-registered to morphological B-scan. The combined set of hybrid images were used to characterize vascular tissue in vitro and in vivo using three mouse models including control (C57BL/6), and atherosclerotic apolipoprotein E-knockout (APOE-KO) and APOE/A1 adenosine receptor double knockout (DKO) mice. The technique was tested using high-frequency ultrasound including single-element (center frequency = 55 MHz) and commercial array (center frequency = 40 MHz) systems providing superior spatial resolutions of 24 ?m and 40 ?m, respectively. Atherosclerotic vascular lesions in the APOE-KO mouse exhibited the highest values (contrast) of ?10.11 ± 1.92 dB, ?12.13 ± 2.13 dB, ?7.54 ± 1.45 dB, ?5.10 ± 1.06 dB, ?5.25 ± 0.94 dB, and ?10.23 ± 2.12 dB in TIB, Tvar, TE, FIB, Wrms, WIB hybrid images (n = 10, p < 0.05), respectively. Control segments of normal vascular tissue showed the lowest values of ?20.20 ± 2.71 dB, ?22.54 ± 4.54 dB, ?14.94 ± 2.05 dB, ?9.64 ± 1.34 dB, ?10.20 ± 1.27 dB, and ?19.36 ± 3.24 dB in same hybrid images (n = 6, p < 0.05). Results from both histology and optical images showed good agreement with ultrasound findings within a maximum error of 3.6% in lesion estimation. This study demonstrated the feasibility of a high-resolution hybrid imaging technique to diagnose atherosclerosis and characterize plaque components in mouse. In the future, it can be easily implemented on commercial ultrasound systems and eventually translated into clinics as a screening tool for atherosclerosis and the assessment of vulnerable plaques. PMID:23218908

Mahmoud, Ahmed M.; Sandoval, Cesar; Teng, Bunyen; Schnermann, Jurgen B.; Martin, Karen H.; Mustafa, S. Jamal; Mukdadi, Osama M.

2012-01-01

57

TissuesTissues TissuesTissues group of similar cell types thatgroup of similar cell types that  

E-print Network

with epithelial tissueMany organs are lined with epithelial tissue Simple Columnar Epithelial TissueSimple Columnar Epithelial Tissue ­­ large intestinelarge intestine TissuesTissues ­­ Epithelial Tissue Pseudostratified ColumarCiliated Pseudostratified Columar Epithelial TissueEpithelial Tissue -- tracheatrachea

Cochran-Stafira, D. Liane

58

Novel Nonlinear Optics and Quantum Optics Approaches for Ultrasound-Modulated Optical Tomography in Soft Biological Tissue  

E-print Network

tomography (UOT): a hybrid technique which combines the advantages of ultrasonic resolution and optical contrast. In this technique, focused ultrasound and optical radiation of high temporal coherence are simultaneously applied to soft biological tissue...

Zhang, Huiliang

2012-02-14

59

Ultrasound  

MedlinePLUS

... couldn't see my baby at my 7 week ultrasound. Why? At the 7th week of pregnancy, your baby is about ½ an ... 1 in 120 pregnancies at 15 to 20 weeks gestation. Most disappear during pregnancy or within several ...

60

Ultrasound evidence of altered lumbar connective tissue structure in human subjects with chronic low back pain  

PubMed Central

Background Although the connective tissues forming the fascial planes of the back have been hypothesized to play a role in the pathogenesis of chronic low back pain (LBP), there have been no previous studies quantitatively evaluating connective tissue structure in this condition. The goal of this study was to perform an ultrasound-based comparison of perimuscular connective tissue structure in the lumbar region in a group of human subjects with chronic or recurrent LBP for more than 12 months, compared with a group of subjects without LBP. Methods In each of 107 human subjects (60 with LBP and 47 without LBP), parasagittal ultrasound images were acquired bilaterally centered on a point 2 cm lateral to the midpoint of the L2-3 interspinous ligament. The outcome measures based on these images were subcutaneous and perimuscular connective tissue thickness and echogenicity measured by ultrasound. Results There were no significant differences in age, sex, body mass index (BMI) or activity levels between LBP and No-LBP groups. Perimuscular thickness and echogenicity were not correlated with age but were positively correlated with BMI. The LBP group had ~25% greater perimuscular thickness and echogenicity compared with the No-LBP group (ANCOVA adjusted for BMI, p < 0.01 and p < 0.001 respectively). Conclusion This is the first report of abnormal connective tissue structure in the lumbar region in a group of subjects with chronic or recurrent LBP. This finding was not attributable to differences in age, sex, BMI or activity level between groups. Possible causes include genetic factors, abnormal movement patterns and chronic inflammation. PMID:19958536

2009-01-01

61

TOMOGRAPHIC RECONSTRUCTION OF TISSUE PROPERTIES AND TEMPERATURE INCREASE FOR HIGH-INTENSITY FOCUSED ULTRASOUND APPLICATIONS  

PubMed Central

The acoustic and thermal properties as well as the temperature change within a tissue volume during high-intensity focused ultrasound ablation are critically important for treatment planning and monitoring. Described in this article is a tomographic reconstruction method used to determine the tissue properties and increase in temperature in a 3-D volume. On the basis of the iterative finite-element solution to the bioheat equation coupled with Tikhonov regularization techniques, our reconstruction algorithm solves the inverse problem of bioheat transfer and uses the time-dependent temperature measured on a tissue surface to obtain the acoustic absorption coefficient, thermal diffusivity and temperature increase within the subsurface volume. Numerical simulations were performed to validate the reconstruction algorithm. The method was initially conducted in ex vivo experiments in which time-dependent temperature on a tissue surface was measured using high-resolution, non-invasive infrared thermography. PMID:23849388

Yin, Lu; Gudur, Madhu Sudhan Reddy; Hsiao, Yi-Sing; Kumon, Ronald E.; Deng, Cheri X.; Jiang, Huabei

2013-01-01

62

Coregistered three-dimensional ultrasound and photoacoustic imaging system for ovarian tissue characterization  

PubMed Central

Ovarian cancer has the highest mortality of all gynecologic cancers, with a five-year survival rate of only 30% or less. Current imaging techniques are limited in sensitivity and specificity in detecting early stage ovarian cancer prior to its widespread metastasis. New imaging techniques that can provide functional and molecular contrasts are needed to reduce the high mortality of this disease. One such promising technique is photoacoustic imaging. We develop a 1280-element coregistered 3-D ultrasound and photoacoustic imaging system based on a 1.75-D acoustic array. Volumetric images over a scan range of 80 deg in azimuth and 20 deg in elevation can be achieved in minutes. The system has been used to image normal porcine ovarian tissue. This is an important step toward better understanding of ovarian cancer optical properties obtained with photoacoustic techniques. To the best of our knowledge, such data are not available in the literature. We present characterization measurements of the system and compare coregistered ultrasound and photoacoustic images of ovarian tissue to histological images. The results show excellent coregistration of ultrasound and photoacoustic images. Strong optical absorption from vasculature, especially highly vascularized corpora lutea and low absorption from follicles, is demonstrated. PMID:19895116

Aguirre, Andres; Guo, Puyun; Gamelin, John; Yan, Shikui; Sanders, Mary M.; Brewer, Molly; Zhu, Quing

2009-01-01

63

Integrated optical coherence tomography, ultrasound and photoacoustic imaging for ovarian tissue characterization  

PubMed Central

Ovarian cancer has the lowest survival rate of the gynecologic cancers because it is predominantly diagnosed in Stages III or IV due to the lack of reliable symptoms, as well as the lack of efficacious screening techniques. Detection before the malignancy spreads or at the early stage would greatly improve the survival and benefit patient health. In this report, we present an integrated optical coherence tomography (OCT), ultrasound (US) and photoacoustic imaging (PAI) prototype endoscopy system for ovarian tissue characterization. The overall diameter of the prototype endoscope is 5 mm which is suitable for insertion through a standard 5-12.5mm endoscopic laparoscopic port during minimally invasive surgery. It consists of a ball-lensed OCT sample arm probe, a multimode fiber having the output end polished at 45 degree angle so as to deliver the light perpendicularly for PAI, and a high frequency ultrasound transducer with 35MHz center frequency. System characterizations of OCT, US and PAI are presented. In addition, results obtained from ex vivo porcine and human ovarian tissues are presented. The optical absorption contrast provided by PAI, the high resolution subsurface morphology provided by OCT, and the deeper tissue structure imaged by US demonstrate the synergy of the combined endoscopy and the superior performance of this hybrid device over each modality alone in ovarian tissue characterization. PMID:21991547

Yang, Yi; Li, Xiang; Wang, Tianheng; Kumavor, Patrick D.; Aguirre, Andres; Shung, Kirk K.; Zhou, Qifa; Sanders, Melinda; Brewer, Molly; Zhu, Quing

2011-01-01

64

High frequency ultrasound measurements of the attenuation and backscatter from biological tissues  

NASA Astrophysics Data System (ADS)

There are now diagnostic ultrasonic imaging devices that operate at very high frequencies (VHF) of 20 MHz and beyond for clinical applications in ophthalmology, dermatology, and vascular surgery. To be able to better interpret these images and to further the development of these devices, knowledge of ultrasonic attenuation and scattering of biological tissues in this high frequency range is crucial. Though currently VHF ultrasound is applied mostly to the eye and skin tissue, in this thesis, VHF experiments were performed on porcine red blood cell suspensions and bovine myocardium, liver, and kidney because these tissues are easy to obtain, are similar in structure to their human counterparts and have been used in ultrasound experiments by many investigators but in a lower frequency range. Attenuation and backscatter coefficients of porcine blood and bovine tissues were measured, respectively, using substitution methods. Unfocused and focused transducers were employed in the experiments and corresponding results were compared. This dissertation presents the results of measurements of acoustic attenuation and backscatter from various biological materials (bovine myocardium, liver, and kidney, and porcine blood) in a wide frequency range (10 to 90 MHz) and compares them to previous lower frequency results. Based on the methods used to calculate the acoustic parameters, the frequency limits of the measurements are also defined.

Maruvada, Subha

65

Synergistic ablation of liver tissue and liver cancer cells with high-intensity focused ultrasound and ethanol.  

PubMed

We investigated the combined effect of ethanol and high-intensity focused ultrasound (HIFU), first, on heating and cavitation bubble activity in tissue-mimicking phantoms and porcine liver tissues and, second, on the viability of HepG2 liver cancer cells. Phantoms or porcine tissues were injected with ethanol and then subjected to HIFU at acoustic power ranging from 1.2 to 20.5 W (HIFU levels 1-7). Cavitation events and the temperature around the focal zone were measured with a passive cavitation detector and embedded type K thermocouples, respectively. HepG2 cells were subjected to 4% ethanol solution in growth medium (v/v) just before the cells were exposed to HIFU at 2.7, 8.7 or 12.0 W for 30 s. Cell viability was measured 2, 24 and 72 h post-treatment. The results indicate that ethanol and HIFU have a synergistic effect on liver cancer ablation as manifested by greater temperature rise and lesion volume in liver tissues and reduced viability of liver cancer cells. This effect is likely caused by reduction of the cavitation threshold in the presence of ethanol and the increased rate of ethanol diffusion through the cell membrane caused by HIFU-induced streaming, sonoporation and heating. PMID:24798386

Hoang, Nguyen H; Murad, Hakm Y; Ratnayaka, Sithira H; Chen, Chong; Khismatullin, Damir B

2014-08-01

66

Harmonic Band Spectrum Analysis of Backscattered Ultrasound from Lesioned and Normal Tissue  

NASA Astrophysics Data System (ADS)

HIFU dose curves (lesion size vs. exposure parameters) exhibit scatter because of local variations in the acoustic properties of tissue. Therefore, clinical applications of HIFU, such as cardiac and cancer ablation, will benefit from the ability to distinguish treated from normal tissue, which can provide the surgeon with lesion monitoring. However, HIFU lesions, especially protein-denaturing lesions (PDLs), may be difficult to visualize with conventional B-mode ultrasound. In this study, spectrum analysis of backscattered radiofrequency (RF) ultrasound was successful in imaging lesions. HIFU lesions were formed at 5 MHz for various intensities and durations in model tissues including degassed chicken breast in vitro, fresh rabbit liver ex vivo, and canine cardiac left ventricle in vivo. The tissues were scanned pre- and post-exposure using confocal array and single-element diagnostic probes incorporated into the HIFU transducer assembly. The diagnostic probes were excited with a monocycle pulse under conditions previously shown to generate a second harmonic comparable in amplitude to the fundamental, and RF echo-signal data were recorded. In an alternate set, the therapy and diagnostic transducers were operated pitch-catch, with the therapy transducer sending out a series of 0.4 ms pulses and the diagnostic transducer in passive receive mode. Spectrum analysis of the RF data was performed separately on first (fundamental) and second harmonic frequency bands. Linear regression fits to spectra computed for sliding regions-of-interest yielded 3 parameters: midband fit (integrated backscatter), y-intercept and slope; grayscale images were produced for each parameter. Differences among the B-mode and parameter images, and between the lesion site and adjacent untreated tissues, were characterized statistically. The results indicate that midband fit images of both the fundamental and harmonic offer improved contrast and lateral resolution compared to conventional images. PDLs and bubbly lesions that are not clearly visible in B-mode images can be imaged with harmonic band spectrum analysis.

Muratore, Robert; Lizzi, Frederic L.; Silverman, Ronald H.

2006-05-01

67

A Feed-forward Neural Network Algorithm to Detect Thermal Lesions Induced by High Intensity Focused Ultrasound in Tissue  

PubMed Central

Non-invasive ultrasound surgeries such as high intensity focused ultrasound have been developed to treat tumors or to stop bleeding. In this technique, incorporation of a suitable imaging modality to monitor and control the treatments is essential so several imaging methods such as X-ray, Magnetic resonance imaging and ultrasound imaging have been proposed to monitor the induced thermal lesions. Currently, the only ultrasound imaging technique that is clinically used for monitoring this treatment is standard pulse-echo B-mode ultrasound imaging. This paper describes a novel method for detecting high intensity focused ultrasound-induced thermal lesions using a feed forward neural-network. This study was carried on in vitro animal tissue samples. Backscattered radio frequency signals were acquired in real-time during treatment in order to detect induced thermal lesions. Changes in various tissue properties including tissue's attenuation coefficient, integrated backscatter, scaling parameter of Nakagami distribution, frequency dependent scatterer amplitudes and tissue vibration derived from the backscattered radio frequency data acquired 10 minutes after treatment regarding to before treatment were used in this study. These estimated parameters were used as features of the neural network. Estimated parameters of two sample tissues including two thermal lesions and their segmented B-mode images were used along with the pathological results as training data for the neural network. The results of the study shows that the trained feed forward neural network could effectively detect thermal lesions in vitro. Comparing the estimated size of the thermal lesion (9.6 mm × 8.5 mm) using neural network with the actual size of that from physical examination (10.1 mm × 9 mm) shows that we could detect high intensity focused ultrasound thermal lesions with the difference of 0.5 mm × 0.5 mm. PMID:23724369

Rangraz, Parisa; Behnam, Hamid; Shakhssalim, Naser; Tavakkoli, Jahan

2012-01-01

68

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

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

69

Adaptive motion estimation of shear shock waves in soft solids and tissue with ultrasound.  

PubMed

Shear shock waves in soft solids, such as in tissue, have different regions of complex motion that can change rapidly across a single wave profile, especially at the shock front. Conventional tracking algorithms are not well adapted to the task of simultaneously tracking the discontinuous shock front and smooth regions away from the shock. An adaptive algorithm based on the normalized cross-correlation and a correlation-weighted median filter is presented. The proposed adaptive algorithm combines two features: first, it adapts the window size to optimize the correlation value based on the deformation, and second, it rejects inaccurate estimates with a median-weighted filter. For simulated ultrasound data, where the displacements are known, it is shown that the estimated velocity error for the adaptive algorithm is less than 1/3 of the error for non-adaptive normalized cross-correlation. The addition of the weighted median filter to the adaptive algorithm significantly improves the shock tracking performance. The shock position and rise-time error is almost an order of magnitude better with the median-weighted filter. This algorithm is then used to track shock wave propagation with data acquired by a high-frame-rate ultrasound scanner in a tissue-mimicking agar and gelatin phantom. The shock front is not resolved with conventional algorithms but it is clearly visible with the proposed adaptive median-weighted algorithm. PMID:25167149

Pinton, Gianmarco; Gennisson, Jean-Luc; Tanter, Mickaël; Coulouvrat, François

2014-09-01

70

Considering Angle Selection When Using Ultrasound Electrode Displacement Elastography to Evaluate Radiofrequency Ablation of Tissues  

PubMed Central

Percutaneous radiofrequency ablation (RFA) is a minimally invasive treatment to thermally destroy tumors. Ultrasound-based electrode-displacement elastography is an emerging technique for evaluating the region of RFA-induced lesions. The angle between the imaging probe and the RFA electrode can influence electrode-displacement elastography when visualizing the ablation zone. We explored the angle effect on electrode-displacement elastography to measure the ablation zone. Phantoms embedded with meatballs were fabricated and then ablated using an RFA system to simulate RFA-induced lesions. For each phantom, a commercial ultrasound scanner with a 7.5?MHz linear probe was used to acquire raw image data at different angles, ranging from 30° to 90° at increments of 10°, to construct electrode-displacement images and facilitate comparisons with tissue section images. The results revealed that the ablation regions detected using electrode-displacement elastography were highly correlated with those from tissue section images when the angle was between 30° and 60°. However, the boundaries of lesions were difficult to distinguish, when the angle was larger than 60°. The experimental findings suggest that angle selection should be considered to achieve reliable electrode-displacement elastography to describe ablation zones. PMID:24971347

Li, Qiang; Chen, Pin-Yu; Wang, Chiao-Yin; Liu, Hao-Li; Teng, Jianfu

2014-01-01

71

Determination of Tissue Thermal Conductivity by Measuring and Modeling Temperature Rise Induced in Tissue by Pulsed Focused Ultrasound  

PubMed Central

A tissue thermal conductivity (Ks) is an important parameter which knowledge is essential whenever thermal fields induced in selected organs are predicted. The main objective of this study was to develop an alternative ultrasonic method for determining Ks of tissues in vitro suitable for living tissues. First, the method involves measuring of temperature-time T(t) rises induced in a tested tissue sample by a pulsed focused ultrasound with measured acoustic properties using thermocouples located on the acoustic beam axis. Measurements were performed for 20-cycle tone bursts with a 2 MHz frequency, 0.2 duty-cycle and 3 different initial pressures corresponding to average acoustic powers equal to 0.7 W, 1.4 W and 2.1 W generated from a circular focused transducer with a diameter of 15 mm and f-number of 1.7 in a two-layer system of media: water/beef liver. Measurement results allowed to determine position of maximum heating located inside the beef liver. It was found that this position is at the same axial distance from the source as the maximum peak-peak pressure calculated for each nonlinear beam produced in the two-layer system of media. Then, the method involves modeling of T(t) at the point of maximum heating and fitting it to the experimental data by adjusting Ks. The averaged value of Ks determined by the proposed method was found to be 0.5±0.02 W/(m·°C) being in good agreement with values determined by other methods. The proposed method is suitable for determining Ks of some animal tissues in vivo (for example a rat liver). PMID:24743838

Kujawska, Tamara; Secomski, Wojciech; Kruglenko, Eleonora; Krawczyk, Kazimierz; Nowicki, Andrzej

2014-01-01

72

Determination of tissue thermal conductivity by measuring and modeling temperature rise induced in tissue by pulsed focused ultrasound.  

PubMed

A tissue thermal conductivity (Ks) is an important parameter which knowledge is essential whenever thermal fields induced in selected organs are predicted. The main objective of this study was to develop an alternative ultrasonic method for determining Ks of tissues in vitro suitable for living tissues. First, the method involves measuring of temperature-time T(t) rises induced in a tested tissue sample by a pulsed focused ultrasound with measured acoustic properties using thermocouples located on the acoustic beam axis. Measurements were performed for 20-cycle tone bursts with a 2 MHz frequency, 0.2 duty-cycle and 3 different initial pressures corresponding to average acoustic powers equal to 0.7 W, 1.4 W and 2.1 W generated from a circular focused transducer with a diameter of 15 mm and f-number of 1.7 in a two-layer system of media: water/beef liver. Measurement results allowed to determine position of maximum heating located inside the beef liver. It was found that this position is at the same axial distance from the source as the maximum peak-peak pressure calculated for each nonlinear beam produced in the two-layer system of media. Then, the method involves modeling of T(t) at the point of maximum heating and fitting it to the experimental data by adjusting Ks. The averaged value of Ks determined by the proposed method was found to be 0.5±0.02 W/(m·°C) being in good agreement with values determined by other methods. The proposed method is suitable for determining Ks of some animal tissues in vivo (for example a rat liver). PMID:24743838

Kujawska, Tamara; Secomski, Wojciech; Kruglenko, Eleonora; Krawczyk, Kazimierz; Nowicki, Andrzej

2014-01-01

73

Ex Vivo characterization of canine liver tissue viscoelasticity after high-intensity focused ultrasound ablation.  

PubMed

The potential of elasticity imaging to detect high-intensity focused ultrasound (HIFU) lesions on the basis of their distinct biomechanical properties is promising. However, information on the quantitative mechanical properties of the tissue and the optimal intensity at which to determine the best contrast parameters is scarce. In this study, fresh canine livers were ablated using combinations of ISPTA intensities of 5.55, 7.16 and 9.07 kW/cm(2) and durations of 10 and 30 s ex vivo, resulting in six groups of ablated tissues. Biopsy samples were then interrogated using dynamic shear mechanical testing within the range of 0.1-10 Hz to characterize the tissue's post-ablation viscoelastic properties. All mechanical parameters were found to be frequency dependent. Compared with unablated cases, all six groups of ablated tissues had statistically significant higher complex shear modulus and shear viscosity. However, among the ablated groups, both complex shear modulus and shear viscosity were found to monotonically increase in groups 1-4 (5.55 kW/cm(2) for 10 s, 7.16 kW/cm(2) for 10 s, 9.07 kW/cm(2) for 10 s, and 5.55 kW/cm(2) for 30 s, respectively), but to decrease in groups 5 and 6 (7.16 kW/cm(2) for 30 s, and 9.07 kW/cm(2) for 30 s, respectively). For groups 5 and 6, the temperature was expected to exceed the boiling point, and therefore, the decreased stiffening could be due to the compromised integrity of the tissue microstructure. Future studies will entail estimation tissue mechanical properties in vivo and perform real-time monitoring of tissue alterations during ablation. PMID:24315395

Shahmirzadi, Danial; Hou, Gary Y; Chen, Jiangang; Konofagou, Elisa E

2014-02-01

74

Prediction of Difficult Laryngoscopy in Obese Patients by Ultrasound Quantification of Anterior Neck Soft Tissue1  

PubMed Central

Prediction of difficult laryngoscopy in obese patients is challenging. In 50 morbidly obese patients, we quantified the neck soft tissue from skin to anterior aspect of trachea at the vocal cords using ultrasound. Thyromental distance <6 cm, mouth opening <4 cm, limited neck mobility, Mallampati score >2, abnormal upper teeth, neck circumference >45 cm, and sleep apnoea were considered predictors of difficult laryngoscopy. Of the nine (18%) difficult laryngoscopy cases, seven had obstructive sleep apnoea history; whereas, only 2 of the 41 easy laryngoscopy patients did (P<0.001). Difficult laryngoscopy patients had larger neck circumference [50 (3.8) vs. 43.5 (2.2) cm; P<0.001] and more pre-tracheal soft tissue [28 (2.7) mm vs. 17.5 (1.8) mm; P<0.001] [mean (SD)]. Soft tissue values completely separated difficult and easy laryngoscopies. None of the other predictors correlated with difficult laryngoscopy. Thus, an abundance of pretracheal soft tissue at the level of vocal cords is a good predictor of difficult laryngoscopy in obese patients. PMID:14616599

Ezri, T.; Gewurtz, G.; Sessler, D.I.; Medalion, B.; Szmuk, P.; Hagberg, C.; Susmallian, S.

2005-01-01

75

High resolution imaging beyond the acoustic diffraction limit in deep tissue via ultrasound-switchable NIR fluorescence.  

PubMed

Fluorescence imaging in deep tissue with high spatial resolution is highly desirable because it can provide details about tissue's structural, functional, and molecular information. Unfortunately, current fluorescence imaging techniques are limited either in penetration depth (microscopy) or spatial resolution (diffuse light based imaging) as a result of strong light scattering in deep tissue. To overcome this limitation, we developed an ultrasound-switchable fluorescence (USF) imaging technique whereby ultrasound was used to switch on/off the emission of near infrared (NIR) fluorophores. We synthesized and characterized unique NIR USF contrast agents. The excellent switching properties of these agents, combined with the sensitive USF imaging system developed in this study, enabled us to image fluorescent targets in deep tissue with spatial resolution beyond the acoustic diffraction limit. PMID:24732947

Pei, Yanbo; Wei, Ming-Yuan; Cheng, Bingbing; Liu, Yuan; Xie, Zhiwei; Nguyen, Kytai; Yuan, Baohong

2014-01-01

76

Implementation of a rotational ultrasound biomicroscopy system equipped with a high-frequency angled needle transducer--ex vivo ultrasound imaging of porcine ocular posterior tissues.  

PubMed

The mechanical scanning of a single element transducer has been mostly utilized for high-frequency ultrasound imaging. However, it requires space for the mechanical motion of the transducer. In this paper, a rotational scanning ultrasound biomicroscopy (UBM) system equipped with a high-frequency angled needle transducer is designed and implemented in order to minimize the space required. It was applied to ex vivo ultrasound imaging of porcine posterior ocular tissues through a minimal incision hole of 1 mm in diameter. The retina and sclera for the one eye were visualized in the relative rotating angle range of 270°~330° and at a distance range of 6~7 mm, whereas the tissues of the other eye were observed in relative angle range of 160°~220° and at a distance range of 7.5~9 mm. The layer between retina and sclera seemed to be bent because the distance between the transducer tip and the layer was varied while the transducer was rotated. Certin features of the rotation system such as the optimal scanning angle, step angle and data length need to be improved for ensure higher accuracy and precision. Moreover, the focal length should be considered for the image quality. This implementation represents the first report of a rotational scanning UBM system. PMID:25254305

Bok, Tae-Hoon; Kim, Juho; Bae, Jinho; Lee, Chong Hyun; Paeng, Dong-Guk

2014-01-01

77

Implementation of a Rotational Ultrasound Biomicroscopy System Equipped with a High-Frequency Angled Needle Transducer -- Ex Vivo Ultrasound Imaging of Porcine Ocular Posterior Tissues  

PubMed Central

The mechanical scanning of a single element transducer has been mostly utilized for high-frequency ultrasound imaging. However, it requires space for the mechanical motion of the transducer. In this paper, a rotational scanning ultrasound biomicroscopy (UBM) system equipped with a high-frequency angled needle transducer is designed and implemented in order to minimize the space required. It was applied to ex vivo ultrasound imaging of porcine posterior ocular tissues through a minimal incision hole of 1 mm in diameter. The retina and sclera for the one eye were visualized in the relative rotating angle range of 270° ? 330° and at a distance range of 6 ? 7 mm, whereas the tissues of the other eye were observed in relative angle range of 160° ? 220° and at a distance range of 7.5 ? 9 mm. The layer between retina and sclera seemed to be bent because the distance between the transducer tip and the layer was varied while the transducer was rotated. Certin features of the rotation system such as the optimal scanning angle, step angle and data length need to be improved for ensure higher accuracy and precision. Moreover, the focal length should be considered for the image quality. This implementation represents the first report of a rotational scanning UBM system. PMID:25254305

Bok, Tae-Hoon; Kim, Juho; Bae, Jinho; Lee, Chong Hyun; Paeng, Dong-Guk

2014-01-01

78

Pulsed ultrasound enhances the delivery of nitric oxide from bubble liposomes to ex vivo porcine carotid tissue  

PubMed Central

Ultrasound-mediated drug delivery is a novel technique for enhancing the penetration of drugs into diseased tissue beds noninvasively. By encapsulating drugs into microsized and nanosized liposomes, the therapeutic can be shielded from degradation within the vasculature until delivery to a target site by ultrasound exposure. Traditional in vitro or ex vivo techniques to quantify this delivery profile include optical approaches, cell culture, and electrophysiology. Here, we demonstrate an approach to characterize the degree of nitric oxide (NO) delivery to porcine carotid tissue by direct measurement of ex vivo vascular tone. An ex vivo perfusion model was adapted to assess ultrasound-mediated delivery of NO. This potent vasodilator was coencapsulated with inert octafluoropropane gas to produce acoustically active bubble liposomes. Porcine carotid arteries were excised post mortem and mounted in a physiologic buffer solution. Vascular tone was assessed in real time by coupling the artery to an isometric force transducer. NO-loaded bubble liposomes were infused into the lumen of the artery, which was exposed to 1 MHz pulsed ultrasound at a peak-to-peak acoustic pressure amplitude of 0.34 MPa. Acoustic cavitation emissions were monitored passively. Changes in vascular tone were measured and compared with control and sham NO bubble liposome exposures. Our results demonstrate that ultrasound-triggered NO release from bubble liposomes induces potent vasorelaxation within porcine carotid arteries (maximal relaxation 31%±8%), which was significantly stronger than vasorelaxation due to NO release from bubble liposomes in the absence of ultrasound (maximal relaxation 7%±3%), and comparable with relaxation due to 12 ?M sodium nitroprusside infusions (maximal relaxation 32%±3%). This approach is a valuable mechanistic tool for assessing the extent of drug release and delivery to the vasculature caused by ultrasound. PMID:25336947

Sutton, JT; Raymond, JL; Verleye, MC; Pyne-Geithman, GJ; Holland, CK

2014-01-01

79

Intraoperative ultrasound for guidance and tissue shift correction in image-guided neurosurgery.  

PubMed

We present a surgical guidance system that incorporates pre-operative image information (e.g., MRI) with intraoperative ultrasound (US) imaging to detect and correct for brain tissue deformation during image-guided neurosurgery (IGNS). Many interactive IGNS implementations employ pre-operative images as a guide to the surgeons throughout the procedure. However, when a craniotomy is involved, tissue movement during a procedure can be a significant source of error in these systems. By incorporating intraoperative US imaging, the target volume can be scanned at any time, and two-dimensional US images may be compared directly to the corresponding slice from the pre-operative image. Homologous points may be mapped from the intraoperative to the pre-operative image space with an accuracy of better than 2 mm, enabling the surgeon to use this information to assess the accuracy of the guidance system along with the progress of the procedure (e.g., extent of lesion removal) at any time during the operation. Anatomical features may be identified on both the pre-operative and intraoperative images and used to generate a deformation map, which can be used to warp the pre-operative image to match the intraoperative US image. System validation is achieved using a deformable multi-modality imaging phantom, and preliminary clinical results are presented. PMID:10798702

Comeau, R M; Sadikot, A F; Fenster, A; Peters, T M

2000-04-01

80

Real-Time Monitoring Of Regional Tissue Elasticity During FUS Focused Ultrasound Therapy Using Harmonic Motion Imaging  

NASA Astrophysics Data System (ADS)

The feasibility of the Harmonic Motion Imaging (HMI) technique for simultaneous monitoring and generation of focused ultrasound therapy using two separate focused ultrasound transducer elements has previously been shown. In this study, a new HMI technique is described that images tissue displacement induced by a harmonic radiation force induced using a single focused ultrasound element. First, wave propagation simulation models were used to compare the use of a single Amplitude-Modulated (AM) focused beam versus two overlapping focused beams as previously implemented for HMI. Simulation results indicated that, unlike in the two-beam configuration, the AM beam produced a consistent, stable focus for the applied harmonic radiation force. The AM beam thus offered the unique advantage of sustaining the application of the spatially-invariant radiation force. Experiments were then performed on gelatin gel phantoms and tissue in vitro bovine liver. The radiation force was generated by a 4.68 MHz focused transducer using a low-frequency Amplitude-Modulated (AM) RF-signal. RF data were acquired at 7.5 MHz with a PRF of 6.5 kHz and displacements were estimated using a 1D cross-correlation algorithm on successive RF signals. Furthermore, taking advantage of the real-time capability of our method, the change in the elastic properties was monitored during focused ultrasound (FUS) ablation of tissue in vitro bovine liver. Based on the harmonic displacements, their temperature-dependence, and the calculated acoustic radiation force, the change in the relative, regional stiffness could be monitored during heating and ablation, both using the displacement amplitude and the resulting phase shift change of the displacement relative to the radiation force temporal profile. In conclusion, the feasibility of using an AM radiation force for HMI for simultaneous monitoring and treatment during ultrasound therapy was demonstrated in phantoms and tissues in vitro. Further study of this method will include, ex vivo and in vivo, stiffness and temperature.

Maleke, Caroline; Pernot, Mathieu; Konofagou, Elisa

2006-05-01

81

Heating of tissues in vivo by pulsed focused ultrasound to stimulate enhanced HSP expression  

NASA Astrophysics Data System (ADS)

The main aim of this work was numerical modeling of temperature fields induced in soft tissues in vivo by pulsed focused ultrasound during neurodegenerative disease treatment and experimental verification of the proposed model for a rat liver. The new therapeutic approach to neurodegenerative diseases consists of stimulation of enhanced expression of the Heat Shock Proteins (HSP) which are responsible for immunity of cells to stress. During therapy the temperature rise in tissues in vivo should not exceed 6 °C above level of the thermal norm (37 °C). First, the 3D acoustic pressure field, and the rate of heat production per unit volume due to that field, were calculated using our 3D numerical solver capable of predicting nonlinear propagation of pulsed high intensity waves generated from circular focused acoustic sources in multilayer configuration of attenuating media. The two-layer configuration of media (water--rat liver) assumed in calculations fairly well approximated both the real anatomic dimensions of rat liver and the geometric scheme of our experimental set-up. A numerical solution of the Pennes bio-heat transfer equation which accounted for the effects of heat diffusion, blood perfusion and metabolism rates, was employed to calculate the temperature fields induced in the rat liver by the ultrasonic beam. The numerical simulation results were verified experimentally using a thermocouple inserted in the liver of a rat under anesthesia at the beam focus. The quantitative analysis of the obtained results enabled estimation of the effects of several acoustic and thermal parameters of the rat liver in vivo on the temperature rise, as well as determination of exposure time for ultrasonic beams with varied acoustic power generated by a 2-MHz circular transducer of 15-mm diameter and 25-mm focal length, in order to avoid the tissue overheating that leads to cells necrosis, which would be unacceptable in neurodegenerative disease treatment.

Kujawska, Tamara; Wójcik, Janusz; Nowicki, Andrzej

2011-09-01

82

Classification algorithm of ovarian tissue based on co-registered ultrasound and photoacoustic tomography  

NASA Astrophysics Data System (ADS)

Human ovarian tissue features extracted from photoacoustic spectra data, beam envelopes and co-registered ultrasound and photoacoustic images are used to characterize cancerous vs. normal processes using a support vector machine (SVM) classifier. The centers of suspicious tumor areas are estimated from the Gaussian fitting of the mean Radon transforms of the photoacoustic image along 0 and 90 degrees. Normalized power spectra are calculated using the Fourier transform of the photoacoustic beamformed data across these suspicious areas, where the spectral slope and 0-MHz intercepts are extracted. Image statistics, envelope histogram fitting and maximum output of 6 composite filters of cancerous or normal patterns along with other previously used features are calculated to compose a total of 17 features. These features are extracted from 169 datasets of 19 ex vivo ovaries. Half of the cancerous and normal datasets are randomly chosen to train a SVM classifier with polynomial kernel and the remainder is used for testing. With 50 times data resampling, the SVM classifier, for the training group, gives 100% sensitivity and 100% specificity. For the testing group, it gives 89.68+/- 6.37% sensitivity and 93.16+/- 3.70% specificity. These results are superior to those obtained earlier by our group using features extracted from photoacoustic raw data or image statistics only.

Li, Hai; Kumavor, Patrick D.; Alqasemi, Umar; Zhu, Quing

2014-03-01

83

Quality assurance for ultrasound scanners using a durable tissue-mimicking phantom and radial MTF  

NASA Astrophysics Data System (ADS)

For the use in routine technical quality assurance (TQA) we developed a tissue-mimicking phantom and an evaluation algorithm. Key properties of US phantom materials are sound velocity and acoustic attenuation. For daily clinical use the material also has to be nontoxic, durable and easy in handling and maintenance. The base material of our phantom is Poly(vinyl alcohol) (PVA), a synthetic polymer. By freezing the phantom body during the production process, it changes its sound velocity to closely match the one of the human body. The phantom's base form is a cuboid containing a large anechoic cylindric target. In routine QA it is required to gain comparable and reproducible results from a single image. To determine spatial resolution of phantom images, we calculate a modulation transfer function (MTF). We developed an algorithm, that calculates a radial MTF from a circular structure representing spatial resolution averaged across all directions. For evaluation of the algorithm, we created a set of synthetic images. A comparison of the results from a traditional slanted edge algorithm and our solution showed a close correlation. The US phantom was imaged with a commercial US-scanner at different sound frequencies. The computed MTFs of higher frequency images show higher transfer percentages in all spatial frequencies than the MTFs of lower frequency images. The results suggest that the proposed method produces clear statements about the spatial resolution of evaluated imaging devices. We therefore consider the method as suitable for application in technical quality assurance of diagnostic ultrasound scanners.

Kaar, Marcus; Semturs, Friedrich; Figl, Michael; Hoffmann, Rainer; Hummel, Johann

2014-03-01

84

Role of Anterior Neck Soft Tissue Quantifications by Ultrasound in Predicting Difficult Laryngoscopy  

PubMed Central

Background The aim of this study was to determine if ultrasound (US) measurements of anterior neck soft tissue thickness at hyoid bone (DSHB), thyrohyoid membrane (DSEM), and anterior commissure (DSAC) levels can be used to predict difficult laryngoscopy. Material/Methods We included 203 patients age 20–65 years scheduled to undergo general anesthesia in this prospective observational study. Correlation analysis and receiver operating characteristic curve (ROC) analysis were used to determine the roles of screening tests [interincisor gap (IIG), thyromental distance (TMD), modified Mallampati score (MMS)] and US measurements (DSHB, DSEM, DSAC) in predicting difficult laryngoscopy. Results There were 28 out of 203 patients categorized as difficult laryngoscopy. DSHB, DSEM, DSAC, and MMS were greater in the difficult laryngoscopy group (P<0.0001). There was a strong positive correlation between DSEM and DSHB (r=0.74); moderate positive correlations between DSEM and DSAC (r=0.60), DSHB and DSAC (r=0.69); small positive correlations between MMS and DSHB (r=0.32), MMS and DSEM (r=0.27), MMS and DSAC (r=0.32), all P values ?0.0001; very small positive correlation between TMD and IIG (r=0.18, P=0.0089); small negative correlation between IIG and MMS (r=?0.27, P=0.0001); and very small negative correlations between MMS and TMD (r=?0.20, P=0.004), IIG and DSAC (r=?0.18, P=0.011), IIG and DSHB (r=?0.15, P=0.034). The areas under the ROC curve (AUCs) of MMS, DSHB, DSEM, and DSAC were significantly larger compared with the reference line (P<0.0001). Conclusions Anterior neck soft tissue thicknesses measured by US at hyoid bone, thyrohyoid membrane, and anterior commissure levels are independent predictors of difficult laryngoscopy. Combinations of those screening tests or risk factors with US measurements might increase the ability to predict difficult laryngoscopy. PMID:25403231

Wu, Jinhong; Dong, Jing; Ding, Yingchun; Zheng, Jijian

2014-01-01

85

Delivery of Colloidal Particles and Red Blood Cells to Tissue Through Microvessel Ruptures Created by Targeted Microbubble Destruction With Ultrasound  

Microsoft Academic Search

Background—We have previously shown that the application of ultrasound to thin-shelled microbubbles flowing through small microvessels (,7 mm in diameter) produces vessel wall ruptures in vivo. Because many intravascular drug- and gene-delivery vehicles are limited by the endothelial barrier, we hypothesized that this phenomenon could be used to deliver drug-bearing vehicles to tissue. Methods and Results—An exteriorized rat spinotrapezius muscle

Richard J. Price; Danny M. Skyba; Sanjiv Kaul; Thomas C. Skalak

2010-01-01

86

Evaluation of an algorithm for semiautomated segmentation of thin tissue layers in high-frequency ultrasound images  

Microsoft Academic Search

An algorithm consisting of speckle reduction by median filtering, contrast enhancement using top- and bottom-hat morphological filters, and segmentation with a discrete dynamic contour (DDC) model was implemented for nondestructive measurements of soft tissue layer thickness. Algorithm performance was evaluated by segmenting simulated images of three-layer phantoms and high-frequency (40 MHz) ultrasound images of porcine aortic valve cusps in vitro.

Qiang Qiu; J. Dunmore-Buyze; D. R. Boughner; J. C. Lacofield

2006-01-01

87

Herpes Simplex Type 1 DNA in Human Brain Tissue  

Microsoft Academic Search

Herpes simplex virus type 1 (HSV-1) is known to reside latently in the trigeminal ganglia of man. Reactivation of this virus causes skin lesions and may occasionally infect other tissues, including the brain. To determine whether the brain tissue of humans free of clinical signs of HSV-1 infection contains any trace of HSV-1, we examined the DNA from brain tissue

Nigel W. Fraser; William C. Lawrence; Zofia Wroblewska; Donald H. Gilden; Hilary Koprowski

1981-01-01

88

Ex vivo viscoelastic characterization of head and neck tissue abnormalities using ultrasound-stimulated vibro-acoustography (USVA)  

NASA Astrophysics Data System (ADS)

In the absence of an imaging technique that offers a highly dynamic range detection of malignant tissue intra-operatively, surgeons are often forced to excise excess healthy tissue to ensure clear margins of resection. Techniques that are currently used in the detection of tumor regions include palpation, optical coherence tomography (OCT) elastography, dye injections, and conventional ultrasound to pinpoint the affected area. However, these methods suffer from limitations such as minimal specificity, low contrast, and limited depth of penetration. Lack of specificity and low contrast result in the production of vague disease margins and fail to provide a reliable guidance tool for surgeons. The proposed work presents an alternative diagnostic technique, ultrasound-stimulated vibro-acoustography (USVA), which may potentially provide surgeons with detailed intra-operative imagery characterized by enhanced structural boundaries and well-defined borders based on the viscoelastic properties of tissues. We demonstrate selective imaging using ex vivo tissue samples of head and neck squamous cell carcinoma (HNSCC) with the presence of both malignant and normal areas. Spatially resolved maps of varying acoustic properties were generated and show good contrast between the areas of interest. While the results are promising, determining the precision and sensitivity of the USVA imaging system in identifying boundary regions as well as intensities of ex vivo tissue targets may provide additional information to non-invasively assess confined regions of diseased tissues from healthy areas.

Maccabi, Ashkan; Garritano, James; Arshi, Armin; Saddik, George; Tajudeen, Bobby A.; St. John, Maie; Grundfest, Warren S.; Taylor, Zachary D.

2014-03-01

89

A high-frame-rate ultrasound system for the study of tissue motions.  

PubMed

In this article, a technique for measuring fast periodic motion is proposed. The sequencing used in this technique is similar to the one used in conventional color Doppler systems. However, a phase correction algorithm is introduced which compensates for the acquisition delays. Criteria for the types of motion which could be detected correctly by the system are developed and presented. Effective frame rates of several hundred hertz to a few kilohertz have been achieved with the system. Applications of the system in tissue elastography are presented together with experimental results from tissue mimicking phantoms. PMID:20639148

Baghani, Ali; Brant, Alex; Salcudean, Septimiu; Rohling, Robert

2010-07-01

90

Spatial and Temporal Controlled Tissue Heating on a Modified Clinical Ultrasound Scanner for Generating Mild Hyperthermia in Tumors  

PubMed Central

A new system is presented for generating controlled tissue heating with a clinical ultrasound scanner, and initial in vitro and in vivo results are presented that demonstrate both transient and sustained heating in the mild-hyperthermia range of 37–42ºC. The system consists of a Siemens Antares™ ultrasound scanner, a custom dual-frequency 3-row transducer array and an external temperature feedback control system. The transducer has 2 outer rows that operate at 1.5 MHz for tissue heating and a center row that operates at 5 MHz for B-mode imaging to guide the therapy. We compare the field maps obtained using a hydrophone against calculations of the ultrasound beam based on monochromatic and linear assumptions. Using the finite-difference time-domain (FDTD) method, we compare predicted time-dependent thermal profiles to measured profiles for soy tofu as a tissue-mimicking phantom. In vitro results show differential heating of 6ºC for chicken breast and tofu. In vivo tests of the system were performed on three mice bearing Met-1 tumors, which is a model of aggressive, metastatic and highly vascular breast cancer. In superficially implanted tumors, we demonstrate controlled heating to 42ºC. We show that the system is able to maintain the temperature to within 0.1ºC of the desired temperature both in vitro and in vivo. PMID:20064754

Kruse, Dustin E.; Lai, Chun-Yen; Stephens, Douglas N.; Sutcliffe, Patrick; Paoli, Eric E.; Barnes, Stephen H.; Ferrara, Katherine W.

2009-01-01

91

TEMPORAL AND SPATIAL MONITORING OF TEMPERATURE-RELATED TISSUE CHANGES USING FOCUSED ULTRASOUND PHASED ARRAYS  

E-print Network

ultrasound-based system could serve as a more applicable alternative to MR techniques for thermal therapy during the application of thermal treatment, such as in the case of Focused Ultrasound Surgery (FUS monitoring. Our plan is to use the same array for the therapy sonication and monitoring of the treatment

Konofagou, Elisa E.

92

Magnetic resonance guided focused ultrasound surgery of uterine fibroids—The tissue effects of GnRH agonist pre-treatment  

Microsoft Academic Search

ObjectiveThe purpose of this study was to determine the ablative effect of magnetic resonance guided focused ultrasound (MRgFUS) on fibroid tissue following the administration of gonadotrophin releasing hormone (GnRH) agonist.

O. C. Smart; J. T. Hindley; L. Regana; W. M. W. Gedroyc

2006-01-01

93

Partial shrinkage of venous tissues near valves using High Intensity Focused Ultrasound  

NASA Astrophysics Data System (ADS)

The cross-section of a vein can be reduced by exposing the collagen of the vein wall to high temperature (85° C) for a few seconds. Partial shrinkage of the vein is appropriate for correcting deformations of valvular tissues that can cause the abnormal blood reflux which is the main cause of varicose veins and Superficial Venous Insufficiency. Due to its suitability for inducing localized heating, High Intensity Focused Ultrasound (HIFU) is a good method for correcting valvular tissue. In the present study, the feasibility of using HIFU for inducing partial shrinkage of the saphenous vein wall is demonstrated. The position and size of valvular deformations are well suited to being heated and, consequently, reduced with HIFU. The resulting shrinkage of deformations should restore normal function of the valve. An experimental protocol was used in which several in vitro segments of human saphenous vein were exposed with a monochromatic signal produced by a real-time imaging HIFU probe. The probe has a focal length of 45 mm, a diameter of 52.5 mm and operates at 3 MHz. Ultrasonic imaging, obtained with an 8-MHz 128-element linear array placed at the centre of the HIFU probe, was used to target the vein. The segment was inserted in a porcine muscle sample, and both were placed into a PVC cylinder. Individual sonications of the vein wall were performed for acoustic power values ranging between 8.75 and 35 W at a constant sonication duration of 5 s. Different durations ranging between 3 and 7 s at constant power were also tested. Finally, a long duration of 18 s was tested while the focal point was displaced along the vein wall at a speed of 0.5 mm/s. Results showed that shrinkage of the vein wall was observed using echographic and macroscopic analysis. In particular, the vein diameter was reduced by 15% for a sonication-duration of 18 s with continuous displacement of the focal point. Results showed that HIFU is suitable for partial shrinkage of the saphenous vein and suggest that correction of dysfunctional valvular tissue is feasible.

Pichardo, Samuel; Curiel, Laura; Milleret, René; Pichot, Olivier; Lacoste, François; Chapelon, Jean-Yves

2005-03-01

94

Toward MR-guided High Intensity Focused Ultrasound for Pre-surgical Localization: Focused Ultrasound Lesions in Cadaveric Breast Tissue  

PubMed Central

Purpose To investigate MR-HIFU as a surgical guide for non-palpable breast tumors by assessing the palpability of MR-HIFU created lesions in ex vivo cadaveric breast tissue. Materials and Methods MR-HIFU ablations spaced 5mm apart were made in 18 locations using the ExAblate2000 system. Ablations formed a square perimeter in mixed adipose and fibroglandular tissue. Ablation was monitored using T1wFSE images. MR-ARFI was used to remotely palpate each ablation location, measuring tissue displacement before and after thermal sonications. Displacement profiles centered at each ablation spot were plotted for comparison. The cadaveric breast was manually palpated to assess stiffness of ablated lesions and dissected for gross examination. This study was repeated on three cadaveric breasts. Results MR-ARFI showed a collective post ablation reduction in peak displacement of 54.8% ([4.41 ± 1.48]?m pre, [1.99 ± 0.82]?m post), and shear wave velocity increase of 65.5%, ([10.69± 1.60] mm pre, [16.33± 3.10] mm post), suggesting tissue became stiffer after the ablation. Manual palpation and dissection of the breast showed increased palpability, a darkening of ablation perimeter, and individual ablations were visible in mixed adipose/fibroglandular tissue. Conclusion The results of this preliminary study show MR-HIFU has the ability to create palpable lesions in ex vivo cadaveric breast tissue, and may potentially be used to pre-operatively localize non-palpable breast tumors. PMID:22170814

Bitton, Rachel R; Kaye, Elena; Dirbas, Frederick M; Daniel, Bruce L; Pauly, Kim Butts

2011-01-01

95

Visualization of multimodal polymer-shelled contrast agents using ultrasound contrast sequences: an experimental study in a tissue mimicking flow phantom  

PubMed Central

Background A multimodal polymer-shelled contrast agent (CA) with target specific potential was recently developed and tested for its acoustic properties in a single element transducer setup. Since the developed polymeric CA has different chemical composition than the commercially available CAs, there is an interest to study its acoustic response when using clinical ultrasound systems. The aim of this study was therefore to investigate the acoustic response by studying the visualization capability and shadowing effect of three polymer-shelled CAs when using optimized sequences for contrast imaging. Methods The acoustic response of three types of the multimodal CA was evaluated in a tissue mimicking flow phantom setup by measuring contrast to tissue ratio (CTR) and acoustic shadowing using five image sequences optimized for contrast imaging. The measurements were performed over a mechanical index (MI) range of 0.2-1.2 at three CA concentrations (106, 105, 104 microbubbles/ml). Results The CTR-values were found to vary with the applied contrast sequence, MI and CA. The highest CTR-values were obtained when a contrast sequence optimized for higher MI imaging was used. At a CA concentration of 106 microbubbles/ml, acoustic shadowing was observed for all contrast sequences and CAs. Conclusions The CAs showed the potential to enhance ultrasound images generated by available contrast sequences. A CA concentration of 106 MBs/ml implies a non-linear relation between MB concentration and image intensity. PMID:23987142

2013-01-01

96

Monitoring tissue inflammation and responses to drug treatments in early stages of mice bone fracture using 50 MHz ultrasound  

PubMed Central

Bone fracture induces moderate inflammatory responses that are regulated by cyclooxygenase-2 (COX-2) or 5-lipoxygenase (5-LO) for initiating tissue repair and bone formation. Only a handful of non-invasive techniques focus on monitoring acute inflammation of injured bone currently exists. In the current study, we monitored in vivo inflammation levels during the initial 2 weeks of the inflammatory stage after mouse bone fracture utilizing 50 MHz ultrasound. The acquired ultrasonic images were correlated well with histological examinations. After the bone fracture in the tibia, dynamic changes in the soft tissue at the medial-posterior compartment near the fracture site were monitored by ultrasound on the days of 0, 2, 4, 7, and 14. The corresponding echogenicity increased on the 2nd, 4th, and 7th day, and subsequently declined to basal levels after the 14th day. An increase of cell death was identified by the positive staining of deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) assay and was consistent with ultrasound measurements. The increases of both COX-2 and Leukotriene B4 receptor 1 (BLT1, 5- LO-relative receptor), which are regulators for tissue inflammation, in the immunohistochemistry staining revealed their involvement in bone fracture injury. Monitoring the inflammatory response to various non-steroidal anti-inflammatory drugs (NSAIDs) treatments was investigated by treating injured mice with a daily oral intake of aspirin (Asp), indomethacin (IND), and a selective COX-2 inhibitor (SC-236). The Asp treatment significantly reduced fracture-increased echogenicity (hyperechogenicity, p < 0.05) in ultrasound images as well as inhibited cell death, and expression of COX-2 and BLT1. In contrast, treatment with IND or SC-236 did not reduce the hyperechogenicity, as confirmed by cell death (TUNEL) and expression levels of COX-2 or BLT1. Taken together, the current study reports the feasibility of a noninvasive ultrasound method capable of monitoring post-fracture tissue inflammation that positively correlates with histological findings. Results of this study also suggest that this approach may be further applied to elucidate the underlying mechanisms of inflammatory processes and to develop therapeutic strategies for facilitating fracture healing. PMID:23871514

Chen, Yen-Chu; Lin, Yi-Hsun; Wang, Shyh-Hau; Lin, Shih-Ping; Shung, K. Kirk; Wu, Chia-Ching

2014-01-01

97

A Tissue-Mimicking Ultrasound Test Object Using Droplet Vaporization to Create Point Targets  

PubMed Central

Ultrasound test objects containing reference point targets could be useful for evaluating ultrasound systems and phase aberration correction methods. Polyacrylamide gels containing albumin-stabilized droplets (3.6 µm mean diameter) of dodecafluoropentane (DDFP) are being developed for this purpose. Perturbation by ultrasound causes spontaneous vaporization of the superheated droplets to form gas bubbles, a process termed acoustic droplet vaporization (ADV). The resulting bubbles (20 to 160 µm diameter) are small compared with acoustic wavelengths in diagnostic ultrasound and are theoretically suitable for use as point targets (phase errors <20° for typical f-numbers). Bubbles distributed throughout the material are convenient for determining the point spread function in an imaging plane or volume. Cooling the gel causes condensation of the DDFP droplets, which may be useful for storage. Studying ADV in such viscoelastic media could provide insight into potential bioeffects from rapid bubble formation. PMID:21937339

Carneal, Catherine M.; Kripfgans, Oliver D.; Krucker, Jochen; Carson, Paul L.; Fowlkes, J. Brian

2012-01-01

98

The effects of Magnetic Resonance Imaging-guided High-Intensity Focused Ultrasound ablation on human cadaver breast tissue.  

PubMed

Magnetic Resonance Imaging-guided High-Intensity Focused Ultrasound (MR-HIFU) is a promising technique for non-invasive breast tumor ablation. The purpose of this study was to investigate the effects of HIFU ablation and thermal exposure on ex vivo human breast tissue. HIFU ablations were performed in three unembalmed cadaveric breast specimens using a clinical MR-HIFU system. Sonications were performed in fibroglandular and adipose tissue. During HIFU ablation, time-resolved anatomical MR images were acquired to monitor macroscopic tissue changes. Furthermore, the breast tissue temperature was measured using a thermocouple to investigate heating and cooling under HIFU exposure. After HIFU ablation, breast tissue samples were excised and prepared for histopathological analysis. In addition, thermal exposure experiments were performed to distinguish between different levels of thermal damage using immunohistochemical staining. Irreversible macroscopic deformations up to 3.7 mm were observed upon HIFU ablation both in fibroglandular and in adipose tissue. No relationship was found between the sonication power or the maximum tissue temperature and the size of the deformations. Temperature measurements after HIFU ablation showed a slow decline in breast tissue temperature. Histopathological analysis of sonicated regions demonstrated ablated tissue and morphologically complete cell death. After thermal exposure, samples exposed to three different temperatures could readily be distinguished. In conclusion, the irreversible macroscopic tissue deformations in ex vivo human breast tissue observed during HIFU ablation suggest that it might be relevant to monitor tissue deformations during MR-HIFU treatments. Furthermore, the slow decrease in breast tissue temperature after HIFU ablation increases the risk of heat accumulation between successive sonications. Since cell death was inflicted after already 5 minutes at 75°C, MR-HIFU may find a place in non-invasive treatment of breast tumors. PMID:23583321

Merckel, Laura G; Deckers, Roel; Baron, Paul; Bleys, Ronald L A W; van Diest, Paul J; Moonen, Chrit T W; Mali, Willem P Th M; van den Bosch, Maurice A A J; Bartels, Lambertus W

2013-10-01

99

Quantitative imaging of young's modulus of soft tissues from ultrasound water jet indentation: a finite element study.  

PubMed

Indentation testing is a widely used approach to evaluate mechanical characteristics of soft tissues quantitatively. Young's modulus of soft tissue can be calculated from the force-deformation data with known tissue thickness and Poisson's ratio using Hayes' equation. Our group previously developed a noncontact indentation system using a water jet as a soft indenter as well as the coupling medium for the propagation of high-frequency ultrasound. The novel system has shown its ability to detect the early degeneration of articular cartilage. However, there is still lack of a quantitative method to extract the intrinsic mechanical properties of soft tissue from water jet indentation. The purpose of this study is to investigate the relationship between the loading-unloading curves and the mechanical properties of soft tissues to provide an imaging technique of tissue mechanical properties. A 3D finite element model of water jet indentation was developed with consideration of finite deformation effect. An improved Hayes' equation has been derived by introducing a new scaling factor which is dependent on Poisson's ratios v, aspect ratio a/h (the radius of the indenter/the thickness of the test tissue), and deformation ratio d/h. With this model, the Young's modulus of soft tissue can be quantitatively evaluated and imaged with the error no more than 2%. PMID:22927890

Lu, Min-Hua; Mao, Rui; Lu, Yin; Liu, Zheng; Wang, Tian-Fu; Chen, Si-Ping

2012-01-01

100

Histotripsy in focused ultrasound surgery: Mechanical ablation of tissue using controlled acoustic cavitation  

NASA Astrophysics Data System (ADS)

This research has investigated non-invasive tissue ablation techniques in ultrasonic surgery that are mediated primarily by the mechanical effects of controlled acoustic cavitation, thereby de-emphasizing the role of thermal coagulation during treatment of diseased tissues. This approach is referred to as "histotripsy," in which soft tissues are broken apart by mechanical agitation, in analogy to established lithotripsy procedures whereby renal stones are similarly comminuted. During histotripsy, cavitation microbubbles are formed endogenously in the treatment volume due to the intense rarefactional pressures (> 20 MPa) incurred. The actions of these microbubbles can impart severe yet highly localized mechanical damage to surrounding cellular architecture. The primary goal of this research was to investigate acoustic methods to control these powerful cavitation effects in order to produce therapeutic soft tissue lesions with minimal thermal invasiveness to surrounding collateral structures. Toward this end, an acoustic pulsing scheme was developed to actively sustain cavitation activity through the use of short-duration (e.g., 15 mus), high-intensity (e.g., 40 kW/cm2 ISPPA) pulses delivered at low repetition frequencies (e.g., 0.17 kHz). This approach maintained the microbubble population during treatment without producing significant temperature elevations (e.g., DeltaT = 5°C). Cavitation-mediated damage morphology in porcine myocardium and renal parenchyma consisted of well-circumscribed, 0.5-1 cm3 voids containing homogenized tissue slurry. Standard histological staining revealed extremely fine pulverization that often bisected single cells. This type of damage morphology offers particular advantages over thermal ablation in applications where diseased or impeding tissue must be physically removed, not merely treated and left in situ. In general, the ability to sustain effective cavitation during histotripsy was strongly influenced by acoustic pulse conditions, as measured by four specific metrics: (i) the prevalence of homogenate within the lesion; (ii) the Young's modulus following treatment; (iii) the degree of spatio-temporal variability in acoustic backscatter; (iv) the duration of light scattering from bubble surfaces inside the lesion, measured using fiber-optic techniques. Consistent trends were observed in the behavior of all four metrics as acoustic input conditions were adjusted, lending supportive evidence that the histotripsy process can be controlled through application of rationally-based pulsing strategies designed to manage resident microbubble activity.

Parsons, Jessica Erin

101

Real-time interlaced ultrasound and photoacoustic system for in vivo ovarian tissue imaging  

NASA Astrophysics Data System (ADS)

In this paper, we report an ultrafast co-registered ultrasound and photoacoustic imaging system based on FPGA parallel processing. The system features 128-channel parallel acquisition and digitization, along with FPGA-based reconfigurable processing for real-time co-registered imaging of up to 15 frames per second that is only limited by the laser pulse repetition frequency of 15 Hz. We demonstrated the imaging capability of the system by live imaging of a mouse tumor model in vivo, and imaging of human ovaries ex vivo. A compact transvaginal probe that includes the PAT illumination using a fiber-optic assembly was used for this purpose. The system has the potential ability to assist a clinician to perform transvaginal ultrasound scanning and to localize the ovarian mass, while simultaneously mapping the light absorption of the ultrasound detected mass to reveal its vasculature using the co-registered PAT.

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

2013-03-01

102

How can Tissue Types be Identified? A Lesson on Identifying and Classifying Animal Tissues  

NSDL National Science Digital Library

The purpose of this inquiry is for students to develop and test a scheme to identify the major types of tissues and to identify similarities and differences in animal tissue types. This is an advanced lab recommended for second year Biology students, 11th or 12th grade. Students should have knowledge of cells and cell organelles. Upon completion of this activity, students will be able to: discuss how tissues can be categorized and recognized, recognize the differences between major types of tissues, and develop a scheme to identify/categorize tissues into related groups. This teaching resource was developed by a K-12 science teacher in the American Physiological SocietyÃÂs 2006 Frontiers in Physiology Program. For more information on this program, please visit www.frontiersinphys.org.

Ramona Lundberg (Deuel High School)

2006-08-01

103

Nondestructive Evaluation of Tissue Engineered Articular Cartilage Using Time-Resolved Fluorescence Spectroscopy and Ultrasound Backscatter Microscopy  

PubMed Central

The goal of this study is to evaluate the ability of a bimodal technique integrating time-resolved fluorescence spectroscopy (TRFS) and ultrasound backscatter microscopy (UBM) for nondestructive detection of changes in the biochemical, structural, and mechanical properties of self-assembled engineered articular cartilage constructs. The cartilage constructs were treated with three chemical agents (collagenase, chondroitinase-ABC, and ribose) to induce changes in biochemical content (collagen and glycosaminoglycan [GAG]) of matured constructs (4 weeks); and to subsequently alter the mechanical properties of the construct. The biochemical changes were evaluated using TRFS. The microstructure and the thickness of the engineered cartilage samples were characterized by UBM. The optical and ultrasound results were validated against those acquired via conventional techniques including collagen and GAG quantification and measurement of construct stiffness. Current results demonstrated that a set of optical parameters (e.g., average fluorescence lifetime and decay constants) showed significant correlation (p<0.05) with biochemical and mechanical data. The high-resolution ultrasound images provided complementary cross-section information of the cartilage samples morphology. Therefore, the technique was capable of nondestructively evaluating the composition of extracellular matrix and the microstructure of engineered tissue, demonstrating great potential as an alternative to traditional destructive assays. PMID:22010819

Responte, Donald; Xie, Hongtao; Liu, Jing; Fatakdawala, Hussain; Hu, Jerry; Athanasiou, Kyriacos A.

2012-01-01

104

5A-3 Spatial and Temporal Controlled Tissue Heating on a Modified Clinical Ultrasound Scanner for Generating Mild Hyperthermia in Tumors  

Microsoft Academic Search

We present a new system for generating controlled tissue heating with a clinical ultrasound scanner and initial in vitro and in vivo results that demonstrate both transient and sustained heating in the mild- hyperthermia range of 37-42degC. The system consists of a Siemens Antarestrade ultrasound scanner, a custom dual-frequency 3-row transducer array, and an external temperature feedback control system. The

Dustin E. Kruse; Douglas N. Stephens; Eric E. Paoli; Stephen H. Barnes; Katherine W. Ferrara

2007-01-01

105

Ultrasound characterization of the seminal vesicles in infertile patients with type 2 diabetes mellitus.  

PubMed

Male patients with type 2 diabetes mellitus (DM) may experience infertility because the disease affects negatively many aspects of reproduction, including seminal vesicle (SV) function. The aim of this study was to evaluate the ultrasound characteristics of the SVs of infertile patients with DM because no such data are available in these patients. To accomplish this, 25 infertile patients with type 2 DM and no other known causes of sperm parameter abnormalities were selected. Two different control groups were also enrolled: healthy men with idiopathic infertility (n=25) and infertile patients with male accessory gland infections (MAGI) (n=25), a well-studied clinical model of SV inflammation. Patients and controls underwent prostate-vesicular transrectal ultrasonography after 1 day of sexual abstinence before and 1h after ejaculation. The following SV ultrasound parameters were recorded: (1) body antero-posterior diameter (ADP); (2) fundus APD; (3) parietal thickness of the right and left SVs; (4) number of polycyclic areas within both SVs; (5) fundus/body ratio; (6) difference of the parietal thickness between the right and the left SV; and (7) pre- and post-ejaculatory APD difference. Patients with DM had a significantly (p<0.05) higher F/B ratio compared to controls and patients with MAGI. Only patients with MAGI had a significantly (p<0.05) higher number of polycyclic areas. Controls and MAGI patients have a similar pre- and post-ejaculatory difference of the body SV APD, whereas this difference was significantly (p<0.05) lower in patients with DM. In conclusion, this study showed that infertile patients with DM have peculiar SV ultrasound features suggestive of functional atony. PMID:20800402

La Vignera, Sandro; Vicari, Enzo; Condorelli, Rosita; D'Agata, Rosario; Calogero, Aldo E

2011-11-01

106

Study on the refractive index matching effect of ultrasound on optical clearing of bio-tissues based on the derivative total reflection method  

PubMed Central

In recent years, the tissue optical clearing (OC) technique in the biomedicine field has drawn lots of attention. Various physical and chemical methods have been introduced to improve the efficacy of OC. In this study, the effect of the combination of glycerol and ultrasound treatment on OC of in vitro porcine muscle tissues has been investigated. The refractive index (RI) matching mechanism of OC was directly observed based on the derivative total reflection method. A theoretical model was used to simulate the proportion of tissue fluid in the illuminated area. Moreover, the total transmittance spectra have been obtained by a spectrometer over the range from 450 nm to 700 nm. The administration of glycerol and ultrasound has led to an increase of the RI of background medium and a more RI matching environment was achieved. The experimental results support the validity of the ultrasound treatment for OC. The RI matching mechanism has been firstly quantitatively analyzed based on the derivative total reflection method.

Zeng, Huanhuan; Wang, Jin; Ye, Qing; Deng, Zhichao; Mei, Jianchun; Zhou, Wenyuan; Zhang, Chunping; Tian, Jianguo

2014-01-01

107

Assessment of Shear Modulus of Tissue Using Ultrasound Radiation Force Acting on a Spherical Acoustic Inhomogeneity  

PubMed Central

An ultrasound-based method to locally assess the shear modulus of a medium is reported. The proposed approach is based on the application of an impulse acoustic radiation force to an inhomogeneity in the medium and subsequent monitoring of the spatio-temporal response. In our experimental studies, a short pulse produced by a 1.5-MHz highly focused ultrasound transducer was used to initiate the motion of a rigid sphere embedded into an elastic medium. Another 25 MHz focused ultrasound transducer operating in pulse-echo mode was used to track the displacement of the sphere. The experiments were performed in gel phantoms with varying shear modulus to demonstrate the relationship between the displacement of the sphere and shear modulus of the surrounding medium. Because the magnitude of acoustic force applied to sphere depends on the acoustic material properties and, therefore, cannot be used to assess the absolute value of shear modulus, the temporal behavior of the displacement of the sphere was analyzed. The results of this study indicate that there is a strong correlation between the shear modulus of a medium and spatio-temporal characteristics of the motion of the rigid sphere embedded in this medium. PMID:19942525

Karpiouk, Andrei B.; Aglyamov, Salavat R.; Ilinskii, Yury A.; Zabolotskaya, Eugenia A.; Emelianov, Stanislav Y.

2011-01-01

108

Method of and Apparatus for Histological Human Tissue Characterization Using Ultrasound  

NASA Technical Reports Server (NTRS)

A method and apparatus for determining important histological characteristics of tissue, including a determination of the tissue's health. Electrical pulses are converted into meaningful numerical representations through the use of Fourier Transforms. These numerical representations are then used to determine important histological characteristics of tissue. This novel invention does not require rectification and thus provides for detailed information from the ultrasonic scan.

Yost, William T. (Inventor); Cantrell, John H. (Inventor); TalEr, George A. (Inventor)

1999-01-01

109

Method of and Apparatus for Histological Human Tissue Characterization Using Ultrasound  

NASA Technical Reports Server (NTRS)

A method and apparatus for determining important histological characteristics of tissue, including a determination of the tissue's health is discussed. Electrical pulses are converted into meaningful numerical representations through the use of Fourier Transforms. These numerical representations are then used to determine important histological characteristics of tissue. This novel invention does not require rectification and thus provides for detailed information from the ultrasonic scan.

Yost, William T. (Inventor); Cantrell, John H. (Inventor); Taler, George A. (Inventor)

1998-01-01

110

DNA methylation age of human tissues and cell types  

PubMed Central

Background It is not yet known whether DNA methylation levels can be used to accurately predict age across a broad spectrum of human tissues and cell types, nor whether the resulting age prediction is a biologically meaningful measure. Results I developed a multi-tissue predictor of age that allows one to estimate the DNA methylation age of most tissues and cell types. The predictor, which is freely available, was developed using 8,000 samples from 82 Illumina DNA methylation array datasets, encompassing 51 healthy tissues and cell types. I found that DNA methylation age has the following properties: first, it is close to zero for embryonic and induced pluripotent stem cells; second, it correlates with cell passage number; third, it gives rise to a highly heritable measure of age acceleration; and, fourth, it is applicable to chimpanzee tissues. Analysis of 6,000 cancer samples from 32 datasets showed that all of the considered 20 cancer types exhibit significant age acceleration, with an average of 36 years. Low age-acceleration of cancer tissue is associated with a high number of somatic mutations and TP53 mutations, while mutations in steroid receptors greatly accelerate DNA methylation age in breast cancer. Finally, I characterize the 353 CpG sites that together form an aging clock in terms of chromatin states and tissue variance. Conclusions I propose that DNA methylation age measures the cumulative effect of an epigenetic maintenance system. This novel epigenetic clock can be used to address a host of questions in developmental biology, cancer and aging research. PMID:24138928

2013-01-01

111

Shock-induced heating and millisecond boiling in gels and tissue due to high intensity focused ultrasound  

PubMed Central

Nonlinear propagation causes high intensity ultrasound waves to distort and generate higher harmonics, which are more readily absorbed and converted to heat than the fundamental frequency. Although such nonlinear effects have previously been investigated and found not to significantly alter high intensity focused ultrasound (HIFU) treatments, two results reported here change this paradigm. One is that at clinically relevant intensity levels, HIFU waves not only become distorted but form shock waves in tissue. The other is that the generated shock waves heat the tissue to boiling in much less time than predicted for undistorted or weakly distorted waves. In this study, a 2-MHz HIFU source operating at peak intensities up to 25,000 W/cm2 was used to heat transparent tissue-mimicking phantoms and ex vivo bovine liver samples. Initiation of boiling was detected using high-speed photography, a 20-MHz passive cavitation detector, and fluctuation of the drive voltage at the HIFU source. The time to boil obtained experimentally was used to quantify heating rates and was compared to calculations using weak shock theory and the shock amplitudes obtained from nonlinear modeling and from measurements with a fiber optic hydrophone. As observed experimentally and predicted by calculations, shocked focal waveforms produced boiling in as little as 3 ms and the time to initiate boiling was sensitive to small changes in HIFU output. Nonlinear heating due to shock waves is therefore important to HIFU and clinicians should be aware of the potential for very rapid boiling since it alters treatments. PMID:20018433

Canney, Michael S.; Khokhlova, Vera A.; Bessonova, Olga V.; Bailey, Michael R.; Crum, Lawrence A.

2009-01-01

112

Tracking of the advance of the coagulation front in a laser irradiated tissue using ultrasound imaging  

E-print Network

-Chair of Committee) ( -6~1 Gerard Cote (Member) Nasser K rnavaz (Co-Chair 'o)nrnitt ray Kuo (I of Department) December JJJP3 Major Subject: Bioengineering ABSTIIACT Trarking ol thc Advance of tlic Coagiilat ion Front in a I. asr r 1rrarliatcrl Tiss... Department for providing the facilities to digitize my ultrasound irliages. I would like to thank Dr. Miller and the Bioengineering Program for all the facilities provided for lny research work. All of the above would not have been possible...

Jagathesan, Shoban Srikrishna

2012-06-07

113

Optimization of Contrast-to-Tissue Ratio by Adaptation of Transmitted Ternary Signal in Ultrasound Pulse Inversion Imaging  

PubMed Central

Ultrasound contrast imaging has provided more accurate medical diagnoses thanks to the development of innovating modalities like the pulse inversion imaging. However, this latter modality that improves the contrast-to-tissue ratio (CTR) is not optimal, since the frequency is manually chosen jointly with the probe. However, an optimal choice of this command is possible, but it requires precise information about the transducer and the medium which can be experimentally difficult to obtain, even inaccessible. It turns out that the optimization can become more complex by taking into account the kind of generators, since the generators of electrical signals in a conventional ultrasound scanner can be unipolar, bipolar, or tripolar. Our aim was to seek the ternary command which maximized the CTR. By combining a genetic algorithm and a closed loop, the system automatically proposed the optimal ternary command. In simulation, the gain compared with the usual ternary signal could reach about 3.9?dB. Another interesting finding was that, in contrast to what is generally accepted, the optimal command was not a fixed-frequency signal but had harmonic components. PMID:23573167

Girault, Jean-Marc

2013-01-01

114

Two Types of Soft Tissue Sarcoma of Uncertain Histogenesis  

PubMed Central

A brief account is given of two types of rare soft tissue sarcoma of uncertain histogenesis. The danger of mistaking the epitheloid sarcoma for a benign lesion is emphasized. ImagesFigs. 3-4Figs. 5-6Figs. 7-8Figs. 1-2Figs. 9-10 PMID:5144520

Mackenzie, D. H.

1971-01-01

115

Two types of brown adipose tissue in humans.  

PubMed

During the last years the existence of metabolically active brown adipose tissue in adult humans has been widely accepted by the research community. Its unique ability to dissipate chemical energy stored in triglycerides as heat makes it an attractive target for new drugs against obesity and its related diseases. Hence the tissue is now subject to intense research, the hypothesis being that an expansion and/or activation of the tissue is associated with a healthy metabolic phenotype. Animal studies provide evidence for the existence of at least two types of brown adipocytes. Apart from the classical brown adipocyte that is found primarily in the interscapular region where it constitutes a thermogenic organ, a second type of brown adipocyte, the so-called beige adipocyte, can appear within white adipose tissue depots. The fact that the two cell types develop from different precursors suggests that they might be recruited and stimulated by different cues and therefore represent two distinct targets for therapeutic intervention. The aim of this commentary is to discuss recent work addressing the question whether also humans possess two types of brown adipocytes and to highlight some issues when looking for molecular markers for such cells. PMID:24575372

Lidell, Martin E; Betz, Matthias J; Enerbäck, Sven

2014-01-01

116

Two types of brown adipose tissue in humans  

PubMed Central

During the last years the existence of metabolically active brown adipose tissue in adult humans has been widely accepted by the research community. Its unique ability to dissipate chemical energy stored in triglycerides as heat makes it an attractive target for new drugs against obesity and its related diseases. Hence the tissue is now subject to intense research, the hypothesis being that an expansion and/or activation of the tissue is associated with a healthy metabolic phenotype. Animal studies provide evidence for the existence of at least two types of brown adipocytes. Apart from the classical brown adipocyte that is found primarily in the interscapular region where it constitutes a thermogenic organ, a second type of brown adipocyte, the so-called beige adipocyte, can appear within white adipose tissue depots. The fact that the two cell types develop from different precursors suggests that they might be recruited and stimulated by different cues and therefore represent two distinct targets for therapeutic intervention. The aim of this commentary is to discuss recent work addressing the question whether also humans possess two types of brown adipocytes and to highlight some issues when looking for molecular markers for such cells. PMID:24575372

Lidell, Martin E; Betz, Matthias J; Enerbäck, Sven

2014-01-01

117

Feasibility of optoacoustic visualization of high-intensity focused ultrasound-induced thermal lesions in live tissue  

NASA Astrophysics Data System (ADS)

A 3-D optoacoustic imaging system was used to visualize thermal lesions produced in vivo using high-intensity focused ultrasound (HIFU). A 7.5-MHz, surgical, focused transducer with a radius of curvature of 35 mm and an aperture diameter of 23 mm was used to generate HIFU. A pulsed laser, which could operate at 755 nm and 1064 nm, was used to illuminate excised tissue and mice using a bifurcated fiber bundle resulting in two wide beams of light. Tomographic images were obtained while the specimens were rotated within a sphere outlined by a concave arc-shaped array of 64 piezo-composite transducers. These images were then combined to reconstruct 3-D volume images (voxel resolution 0.5 mm), which were acquired before and after HIFU exposure. In vivo optoacoustic images acquired at 1064 nm provided visualization of HIFU lesions. The lesion was indicated by a negative optoacoustic contrast. The molecular nature of such contrast may possibly be associated with reduction of the optical absorption due to reduced concentration of blood, tissue dehydration, denaturation of proteins and porphyrins, and reduction of thermoacoustic efficiency in the thermally treated tissue. These preliminary results demonstrate the potential of optoacoustic imaging to assess and monitor the progress of HIFU therapy.

Chitnis, Parag V.; Brecht, Hans-Peter; Su, Richard; Oraevsky, Alexander A.

2010-03-01

118

Backward-mode multiwavelength photoacoustic scanner using a planar Fabry-Perot polymer film ultrasound sensor for high-resolution three-dimensional imaging of biological tissues  

Microsoft Academic Search

A multiwavelength backward-mode planar photoacoustic scanner for 3D imaging of soft tissues to depths of several millimeters with a spatial resolution in the tens to hundreds of micrometers range is described. The system comprises a tunable optical parametric oscillator laser system that provides nanosecond laser pulses between 600 and 1200 nm for generating the photoacoustic signals and an optical ultrasound

Edward Zhang; Jan Laufer; Paul Beard

2008-01-01

119

The role of acoustic nonlinearity in tissue heating behind the rib cage using high intensity focused ultrasound phased array  

PubMed Central

The goal of this study was to investigate theoretically the effects of nonlinear propagation in a high intensity focused ultrasound (HIFU) field produced by a therapeutic phased array and the resultant heating of tissue behind a rib cage. Three configurations of focusing were simulated: in water, in water with ribs in the beam path, and in water with ribs backed by a layer of soft tissue. The Westervelt equation was used to model the nonlinear HIFU field and a 1 MHz phased array consisting of 254 circular elements was used as a boundary condition to the model. The temperature rise in tissue was modelled using the bioheat equation, and thermally necrosed volumes were calculated using the thermal dose formulation. The shapes of lesions predicted by the modelling were compared with those previously obtained in in vitro experiments at low power sonications. Intensity levels at the face of the array elements that corresponded to formation of high amplitude shock fronts in the focal region were determined as 10 W·cm?2 in the free field in water and 40 W·cm?2 in the presence of ribs. It was shown that exposures with shocks provided a substantial increase in tissue heating, and its better spatial localization in the main focal region only. The relative effects of overheating ribs and splitting of the focus due to the periodic structure of the ribs were therefore reduced. These results suggest that utilizing nonlinear propagation and shock formation effects can be beneficial for inducing confined HIFU lesions when irradiating through obstructions such as ribs. Design of compact therapeutic arrays to provide maximum power outputs with lower intensity levels at the elements is necessary to achieve shock wave regimes for clinically relevant sonication depths in tissue. PMID:23528338

Yuldashev, Petr V.; Shmeleva, Svetlana M.; Ilyin, Sergey A.; Sapozhnikov, Oleg A.; Gavrilov, Leonid R.; Khokhlova, Vera A.

2013-01-01

120

An improved tissue-mimicking polyacrylamide hydrogel phantom for visualizing thermal lesions with high-intensity focused ultrasound.  

PubMed

A recipe was created to improve the tissue-mimicking (TM) bovine serum albumin (BSA) polyacrylamide hydrogel (PAG) reported in our previous study (Choi MJ, Guntur SR, Lee KI, Paeng DG, Coleman AJ. Ultrasound Med Biol 2013; 29:439-448). In that work, the concentration of acrylamide in TM BSA PAG was increased to make its attenuation coefficient the same as that of a tissue. However, this increase made the PAG stiffer and less homogeneous. In addition, the increase in acrylamide caused a significant increase in temperature over the denaturation threshold of BSA during polymerization, which required forced cooling so that the PAG did not become opaque at room temperature after polymerization. To eliminate those shortcomings, we substituted the increased acrylamide with a viscous polysaccharide liquid (corn syrup). The concentration of corn syrup was optimized to 20% (w/v, tested in the volume of 50 mL), so that the acoustic properties of the PAG would be close to those of human liver. The improved TM (iTM) BSA PAG constructed in this study had a speed of sound of 1588 ± 9 m/s, an attenuation coefficient of 0.51 ± 0.06 dB cm(-1) at 1 MHz and a backscattering coefficient of 0.22 ± 0.09 × 10(-3) sr(-1) cm(-1) MHz(-1). The density and acoustic impedance were 1057 kg/m(3) and 1.68 MRayl, respectively, and the non-linear parameter (B/A) was 5.9 ± 0.3. The thermal, optical and mechanical properties were almost the same as those of the BSA PAG (Lafon et al.2005). Experimental verification indicated that the thermal lesions visualized in the proposed iTM BSA PAG by high-intensity focused ultrasound were highly reproducible. In conclusion, iTM BSA PAG was proven to eliminate TM BSA PAG shortcomings effectively and is expected to be a promising test phantom for clinical high-intensity focused ultrasound device. PMID:25220272

Guntur, Sitaramanjaneya Reddy; Choi, Min Joo

2014-11-01

121

Heart rate, conduction and ultrasound abnormalities in adults with joint hypermobility syndrome/Ehlers-Danlos syndrome, hypermobility type.  

PubMed

Joint hypermobility syndrome (JHS) and Ehlers-Danlos syndrome, hypermobility type (EDS-HT) are two clinically overlapping heritable connective tissue disorders strongly associating with pain, fatigue and other secondary aspects. Though not considered a diagnostic criterion for most EDS subtypes, cardiovascular involvement is a well-known complication in EDS. A case-control study was carried out on 28 adults with JHS/EDS-HT diagnosed according to current criteria, compared to 29 healthy subjects evaluating resting electrocardiographic (ECG), 24-h ECG and resting heart ultrasound data. Results obtained in the ECG studies showed a moderate excess in duration of the PR interval and P wave, an excess of heart conduction and rate abnormalities and an increased rate of mitral and tricuspid valve insufficiency often complicating with "true" mitral valve prolapse in the ecocardiographic study. These variable ECG subclinical anomalies reported in our sample may represent the resting surrogate of such a subnormal cardiovascular response to postural changes that are known to be present in patients with JHS/EDS-HT. Our findings indicate the usefulness of a full cardiologic evaluation of adults with JHS/EDS-HT for the correct management. PMID:24752348

Camerota, Filippo; Castori, Marco; Celletti, Claudia; Colotto, Marco; Amato, Silvia; Colella, Alessandra; Curione, Mario; Danese, Chiara

2014-07-01

122

Ultrasound assisted synthesis and characterization of M50 type nanostructured steel  

SciTech Connect

A nanophase multicomponent (Fe-Cr-Mo-V-C) type steel was prepared via the ultrasound decomposition of organometallic precursors. The synthesis involved the sonication of a mixture of iron pentacarbonyl, bis(ethylbenzene)chromium, bis(ethyl benzene)molybdenum and vanadium hexacarbonyl in decalin at 0{degrees}C. The as-synthesized powders are amorphous as determined by XRD. The nanopowders were compacted into a dense bulk sample which was then characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive analysis x-ray (EDAX). The major peaks in the X-ray spectra of the consolidated sample were assigned to {alpha}-Fe and the line broadening analysis revealed the crystallite size in the sample to be 27 nm. The hardness of the sample was estimated to be 66.3 Rockwell C.

Gonsalves, K.E.; Chen, X.; Rangarajan, S.P. [Univ. of Connecticut, Storrs, CT (United States)] [and others

1995-12-31

123

Ultrasound studies.  

PubMed

This article focuses on the clinical use of ultrasound with the obstetric, gynecologic, and trauma patient by reviewing recent case studies of the use of ultrasound for diagnostic purposes. The article also summarizes the American Institute of Ultrasound in Medicine (AIUM) guidelines for use in several types of patients. The AIUM is a multidisciplinary association whose purpose is to "advance the art and science of ultrasound in medicine and research through educational, scientific, literary, and professional activities." The organization provides guidelines in conjunction with many professional organizations, such as the American College of Cardiology and the American College of Obstetrics and Gynecology. AIUM also serves as an accrediting body for ultrasound practices. PMID:20193883

Smith-Francis, Melan; Orr, Patty

2010-03-01

124

Natural course of small adrenal lesions in multiple endocrine neoplasia type 1: an endoscopic ultrasound imaging study  

Microsoft Academic Search

Objective: Adrenal lesion is one of the features of multiple endocrine neoplasia type 1 (MEN1). This study aimed to assess prevalence, natural course and clinical relevance of small adrenal lesions without clinical symptoms, endocrine activity, or mechanical problems and thus without clear indication for surgical therapy by endoscopic ultrasound (EUS). Design and methods: Forty-nine patients with familial MEN1 were studied.

S Schaefer; M Shipotko; S Meyer; D Ivan; K J Klose; J Waldmann; P Langer; P H Kann

2008-01-01

125

Study of Tissue Phantoms, Tissues, and Contrast Agent with the Biophotoacoustic Radar and Comparison to Ultrasound Imaging for Deep Subsurface Imaging  

NASA Astrophysics Data System (ADS)

In this study, the imaging capability of our wide-spectrum frequency-domain photoacoustic (FD-PA) imaging alias "photoacoustic radar" methodology for imaging of soft tissues is explored. A practical application of the mathematical correlation processing method with relatively long (1 ms) frequency-modulated optical excitation is demonstrated for reconstruction of the spatial location of the PA sources. Image comparison with ultrasound (US) modality was investigated to see the complementarity between the two techniques. The obtained results with a phased array probe on tissue phantoms and their comparison to US images demonstrated that the FD-PA technique has strong potential for deep subsurface imaging with excellent contrast and high signal-to-noise ratio. FD-PA images of blood vessels in a human wrist and an in vivo subcutaneous tumor in a rat model are presented. As in other imaging modalities, the employment of contrast agents is desirable to improve the capability of medical diagnostics. Therefore, this study also evaluated and characterized the use of Food and Drug Administration (FDA)-approved superparamagnetic iron oxide nanoparticles (SPION) as PA contrast agents.

Alwi, R.; Telenkov, S.; Mandelis, A.; Gu, F.

2012-11-01

126

Thresholds for nonlinear effects in high- intensity focused ultrasound propagation and tissue heating.  

PubMed

For a variety of reasons, including their simplicity and ability to capitalize upon superposition, linear acoustic propagation models are preferable to nonlinear ones in modeling the propagation of high-intensity focused ultrasound (HIFU) beams. However, under certain conditions, nonlinear models are necessary to accurately model the beam propagation and heating. In analyzing the performance of a HIFU system, it is advantageous to know before the analysis whether a linear model suffices. This paper examines the problem of determining the thresholds at which nonlinear effects become important. It is demonstrated that nonlinear interaction has different effects on different physical and derived quantities, such as compressional pressure, rarefactional pressure, intensity, heat rate, temperature rise, and thermal lesion volume. Thresholds are determined as a function of the dimensionless gain, nonlinearity, and absorption parameters. The relative difference between linear and nonlinear predictions is plotted as a series of contours, enabling practitioners to locate their system in parameter space and determine whether nonlinearity significantly affects the quantities of interest. PMID:21041132

Soneson, Joshua E; Myers, Matthew R

2010-11-01

127

Characterization of tissue-simulating phantom materials for ultrasound-guided needle procedures  

NASA Astrophysics Data System (ADS)

Needle biopsies are standard protocols that are commonly performed under ultrasound (US) guidance or computed tomography (CT)1. Vascular access such as central line insertions, and many spinal needle therapies also rely on US guidance. Phantoms for these procedures are crucial as both training tools for clinicians and research tools for developing new guidance systems. Realistic imaging properties and material longevity are critical qualities for needle guidance phantoms. However, current commercially available phantoms for use with US guidance have many limitations, the most detrimental of which include harsh needle tracks obfuscating US images and a membrane comparable to human skin that does not allow seepage of inner media. To overcome these difficulties, we tested a variety of readily available media and membranes to evaluate optimal materials to fit our current needs. It was concluded that liquid hand soap was the best medium, as it instantly left no needle tracks, had an acceptable depth of US penetration and portrayed realistic imaging conditions, while because of its low leakage, low cost, acceptable durability and transparency, the optimal membrane was 10 gauge vinyl.

Buchanan, Susan; Moore, John; Lammers, Deanna; Baxter, John; Peters, Terry

2012-02-01

128

Miniaturized fiber-optic ultrasound probes for endoscopic tissue analysis by micro-opto-mechanical technology.  

PubMed

A new Micro-Opto-Mechanical System (MOMS) technology for the fabrication of optoacoustic probes on optical fiber is presented. The technology is based on the thermoelastic emission of ultrasonic waves from patterned carbon films for generation and on extrinsic polymer Fabry-Perot acousto-optical transducers for detection, both fabricated on miniaturized single-crystal silicon frames used to mount the ultrasonic transducers on the tip of an optical fiber. Thanks to the fabrication process adopted, high miniaturization levels are reached in the MOMS devices, demonstrating fiber-optic emitters and detectors with minimum diameter around 350 and 250 ?m respectively. A thorough functional testing of the ultrasound emitters mounted on 200 and 600 ?m diameter optical fibers is presented, in which the fiber-optic emitter with a diameter of 200 ?m shows generated acoustic pressures with peak-to-peak value up to 2.8 MPa with rather flat emission spectra extended beyond 150 MHz. The possibility to use the presented optoacoustic sources in conjunction with the fiber-optic acousto-optical detectors within a minimally invasive probe is also demonstrated by successfully measuring the ultrasonic echo reflected from a rigid surface immersed in water with various concentration of scatterers. The resulting spectra highlight the possibility to discriminate the effects due to frequency selective attenuation in a very wide range of frequencies within a biological medium using the presented fiber-optic probes. PMID:24573502

Vannacci, E; Belsito, L; Mancarella, F; Ferri, M; Veronese, G P; Roncaglia, A; Biagi, E

2014-06-01

129

Tissue type plasminogen activator regulates myeloid-cell dependent neoangiogenesis during tissue regeneration  

PubMed Central

Ischemia of the heart, brain, and limbs is a leading cause of morbidity and mortality worldwide. Treatment with tissue type plasminogen activator (tPA) can dissolve blood clots and can ameliorate the clinical outcome in ischemic diseases. But the underlying mechanism by which tPA improves ischemic tissue regeneration is not well understood. Bone marrow (BM)–derived myeloid cells facilitate angiogenesis during tissue regeneration. Here, we report that a serpin-resistant form of tPA by activating the extracellular proteases matrix metalloproteinase-9 and plasmin expands the myeloid cell pool and mobilizes CD45+CD11b+ proangiogenic, myeloid cells, a process dependent on vascular endothelial growth factor-A (VEGF-A) and Kit ligand signaling. tPA improves the incorporation of CD11b+ cells into ischemic tissues and increases expression of neoangiogenesis-related genes, including VEGF-A. Remarkably, transplantation of BM-derived tPA-mobilized CD11b+ cells and VEGFR-1+ cells, but not carrier-mobilized cells or CD11b? cells, accelerates neovascularization and ischemic tissue regeneration. Inhibition of VEGF signaling suppresses tPA-induced neovascularization in a model of hind limb ischemia. Thus, tPA mobilizes CD11b+ cells from the BM and increases systemic and local (cellular) VEGF-A, which can locally promote angiogenesis during ischemic recovery. tPA might be useful to induce therapeutic revascularization in the growing field of regenerative medicine. PMID:20110420

Ohki, Makiko; Ohki, Yuichi; Ishihara, Makoto; Nishida, Chiemi; Tashiro, Yoshihiko; Akiyama, Haruyo; Komiyama, Hiromitsu; Lund, Leif R.; Nitta, Atsumi; Yamada, Kiyofumi; Zhu, Zhenping; Ogawa, Hideoki; Yagita, Hideo; Okumura, Ko; Nakauchi, Hiromitsu; Werb, Zena; Heissig, Beate

2010-01-01

130

Needle Steering in Biological Tissue using Ultrasound-based Online Curvature Estimation  

E-print Network

are commonly per- formed for diagnostic and therapeutic purposes. Accurate placement of the needle tip. The average targeting error using our new adaptive method is 40% lower than using the conventional non-adaptive duty-cycled needle steering method. I. INTRODUCTION Needle insertion in soft tissues is a common step

North Carolina at Chapel Hill, University of

131

Experimental ultrasound characterization of tissue-mimicking phantoms with high scatterer volume  

E-print Network

theoretical scattering models such that the fluid-filled sphere model [5] [6] or the solid sphere model [7 the tissues by an ensemble of fluid or solid spheres. The aforementioned models (Gaussian model, fluid and monitor diseases, such as cancer. The Gaussian Model (GM) and Fluid-Filled Sphere Model (FFSM) have been

Boyer, Edmond

132

Assessment of the effects of ultrasound-mediated glucose on permeability of normal, benign, and cancerous human lung tissues with the Fourier-domain optical coherence tomography  

NASA Astrophysics Data System (ADS)

The objective of this study was to evaluate the effects of ultrasound-mediated analyte diffusion on permeability of normal, benign, and cancerous human lung tissue in vitro and to find more effective sonophoretic (SP) delivery in combination with the optical clearing agents (OCAs) method to distinguish normal and diseased lung tissues. The permeability coefficients of SP in combination with OCAs diffusion in lung tissue were measured with Fourier-domain optical coherence tomography (FD-OCT). 30% glucose and SP with a frequency of 1 MHz and an intensity of 0.80 W/cm2 over a 3 cm probe was simultaneously applied for 15 min. Experimental results show that the mean permeability coefficients of 30% glucose/SP were found to be (2.01±0.21)×10-5 cm/s from normal lung (NL) tissue, (2.75±0.28)×10-5 cm/s from lung benign granulomatosis (LBG) tissue, (4.53±0.49)×10-5 cm/s from lung adenocarcinoma tumor (LAT) tissue, and (5.81±0.62)×10-5 cm/s from lung squamous cell carcinoma (LSCC) tissue, respectively. The permeability coefficients of 30% glucose/SP increase approximately 36.8%, 125.4%, and 189.1% for the LBG, LAT, and LSCC tissue compared with that for the NL tissue, respectively. There were statistically significant differences in permeability coefficients of 30% glucose/SP between LBG and NL tissue (p<0.05), between LAT and NL tissue (p<0.05), and between LSCC and NL tissue (p<0.05). The results suggest that the OCT functional imaging technique to combine an ultrasound-OCAs combination method could become a powerful tool in early diagnosis and monitoring of changed microstructure of pathologic human lung tissue.

Wei, Huajiang; Wu, Guoyong; Guo, Zhouyi; Yang, Hongqin; He, Yonghong; Xie, Shusen; Guo, Xiao

2012-11-01

133

Virtual Touch Tissue Quantification of Acoustic Radiation Force Impulse: A New Ultrasound Elastic Imaging in the Diagnosis of Thyroid Nodules  

PubMed Central

Objective Virtual touch tissue quantification (VTQ) of acoustic radiation force impulse (ARFI) is a new quantitative technique to measure tissue stiffness. The study was aimed to assess the usefulness of VTQ in the diagnosis of thyroid nodules. Methods 173 pathologically proven thyroid nodules in 142 patients were included and all were examined by conventional ultrasound (US), conventional elasticity imaging (EI) and VTQ of ARFI. The tissue stiffness for VTQ was expressed as shear wave velocity (SWV) (m/s). Receiver-operating characteristic curve (ROC) analyses were performed to assess the diagnostic performance. Intra- and inter-observer reproducibility of VTQ measurement was assessed. Results The SWVs of benign and malignant thyroid nodules were 2.34±1.17 m/s (range: 0.61–9.00 m/s) and 4.82±2.53 m/s (range: 2.32–9.00 m/s) respectively (P<0.001). The mean SWV ratios between each nodule and the adjacent thyroid tissue were 1.19±0.67 (range: 0.31–6.87) for benign and 2.50±1.54 (range: 0.85–6.69) for malignant nodules (P<0.001). ROC analyses indicated that the area under the curve was 0.861 (95% CI : 0.804, 0.918) (P<0.001) for SWV and 0.831(95% CI : 0.761, 0.900)(P<0.001) for the SWV ratio. The cutoff points for the differential diagnosis were 2.87 m/s for SWV and 1.59 for SWV ratio. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for EI were 65.9%, 66.7%, 66.5%, 40.3%, and 85.1%, respectively, and were 63.6%–75%, 82.2%–88.4%, 80.3%–82.1%, 58.9%–65.1%, and 87.7%–90.5%, respectively, for VTQ. The diagnostic value of VTQ is the highest for nodules >20 mm and lowest for those ?10 mm. The correlation coefficients were 0.904 for intraobserver measurement and 0.864 for interobserver measurement. Conclusions VTQ of ARFI provides quantitative and reproducible information about the tissue stiffness, which is useful for the differentiation between benign and malignant thyroid nodules. The diagnostic performance of VTQ is higher than that of conventional EI. PMID:23152855

Zhang, Yi-Feng; Xu, Hui-Xiong; He, Yong; Liu, Chang; Guo, Le-Hang; Liu, Lin-Na; Xu, Jun-Mei

2012-01-01

134

Increased tissue kallikrein levels in type 2 diabetes  

Microsoft Academic Search

Aims\\/hypothesis  We measured components of the kallikrein–kinin system in human type 2 diabetes mellitus and the effects of statin therapy\\u000a on the circulating kallikrein–kinin system.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Circulating levels of bradykinin and kallidin peptides, and high and low molecular weight kininogens, as well as plasma and\\u000a tissue kallikrein, and kallistatin were measured in non-diabetic and diabetic patients before coronary artery bypass graft\\u000a surgery.

D. J. Campbell; A. Kladis; Y. Zhang; A. J. Jenkins; D. L. Prior; M. Yii; J. F. Kenny; M. J. Black; D. J. Kelly

2010-01-01

135

Multimodal ultrasound-photoacoustic imaging of tissue engineering scaffolds and blood oxygen saturation in and around the scaffolds.  

PubMed

Preclinical, noninvasive imaging of tissue engineering polymeric scaffold structure and/or the physiological processes such as blood oxygenation remains a challenge. In vitro or ex vivo, the widely used scaffold characterization modalities such as porosimetry, electron or optical microscopy, and X-ray microcomputed tomography have limitations or disadvantages-some are invasive or destructive, others have limited tissue penetration (few hundred micrometers) and/or show poor contrast under physiological conditions. Postmortem histological analysis, the most robust technique for the evaluation of neovascularization is obviously not appropriate for acquiring physiological or longitudinal data. In this study, we have explored the potential of ultrasound (US)-coregistered photoacoustic (PA) imaging as a noninvasive multimodal imaging modality to overcome some of the above challenges and/or provide complementary information. US-PA imaging was employed to characterize poly(lactic-co-glycolic acid) (PLGA) polymer scaffolds or single-walled carbon nanotube (SWCNT)-incorporated PLGA (SWCNT-PLGA) polymer scaffolds as well as blood oxygen saturation within and around the scaffolds. Ex vivo, PLGA and SWCNT-PLGA scaffolds were placed at 0.5, 2, and 6 mm depths in chicken breast tissues. PLGA scaffolds could be localized with US imaging, but generate no PA signal (excitation wavelengths 680 and 780 nm). SWCNT-PLGA scaffolds generated strong PA signals at both wavelengths due to the presence of the SWCNTs and could be localized with both US and PA imaging depths between 0.5-6 mm (lateral resolution = 90 ?m, axial resolution = 40 ?m). In vivo, PLGA and SWCNT-PLGA scaffolds were implanted in subcutaneous pockets at 2 mm depth in rats, and imaged at 7 and 14 days postsurgery. The anatomical position of both the scaffolds could be determined from the US images. Only SWCNT-PLGA scaffolds could be easily detected in the US-PA images. SWCNT-PLGA scaffolds had significant four times higher PA signal intensity compared with the surrounding tissue and PLGA scaffolds. In vivo blood oxygen saturation maps around and within the PLGA scaffolds could be obtained by PA imaging. There was no significant difference in oxygen saturation for the PLGA scaffolds at the two time points. The blood oxygen saturation maps complemented the histological analysis of neovascularization of the PLGA scaffolds. PMID:24107069

Talukdar, Yahfi; Avti, Pramod; Sun, John; Sitharaman, Balaji

2014-05-01

136

Overexpression of type VI collagen in neoplastic lung tissues.  

PubMed

Type VI collagen (COL6), an extracellular matrix protein, is important in maintaining the integrity of lung tissue. An increase in COL6 mRNA and protein deposition was found in the lungs of patients with pulmonary fibrosis, a chronic inflammatory condition with a strong association with lung cancer. In the present study, we demonstrated overexpression of COL6 in the lungs of non-small cell lung cancers. We hypothesized that excessive COL6 in the lung interstitium may exert stimulatory effects on the adjacent cells. In vitro stimulation of monocytes with COL6 resulted in the production of IL-23, which may promote tumor development in an environment of IL-23-mediated lung inflammation, where tissue modeling occurs concurrently with excessive COL6 production. In addition, COL6 was capable of stimulating signaling pathways that activate focal adhesion kinase and extracellular signal?regulated kinase 1/2 in lung epithelial cells, which may also facilitate the development of lung neoplasms. Taken together, our data suggest the potential role of COL6 in promoting lung neoplasia in diseased lungs where COL6 is overexpressed. PMID:25176343

Voiles, Larry; Lewis, David E; Han, Ling; Lupov, Ivan P; Lin, Tsang-Long; Robertson, Michael J; Petrache, Irina; Chang, Hua-Chen

2014-11-01

137

Overexpression of type VI collagen in neoplastic lung tissues  

PubMed Central

Type VI collagen (COL6), an extracellular matrix protein, is important in maintaining the integrity of lung tissue. An increase in COL6 mRNA and protein deposition was found in the lungs of patients with pulmonary fibrosis, a chronic inflammatory condition with a strong association with lung cancer. In the present study, we demonstrated overexpression of COL6 in the lungs of non-small cell lung cancers. We hypothesized that excessive COL6 in the lung interstitium may exert stimulatory effects on the adjacent cells. In vitro stimulation of monocytes with COL6 resulted in the production of IL-23, which may promote tumor development in an environment of IL-23-mediated lung inflammation, where tissue modeling occurs concurrently with excessive COL6 production. In addition, COL6 was capable of stimulating signaling pathways that activate focal adhesion kinase and extracellular signal-regulated kinase 1/2 in lung epithelial cells, which may also facilitate the development of lung neoplasms. Taken together, our data suggest the potential role of COL6 in promoting lung neoplasia in diseased lungs where COL6 is overexpressed. PMID:25176343

VOILES, LARRY; LEWIS, DAVID E.; HAN, LING; LUPOV, IVAN P.; LIN, TSANG-LONG; ROBERTSON, MICHAEL J.; PETRACHE, IRINA; CHANG, HUA-CHEN

2014-01-01

138

Origins of the specificity of tissue-type plasminogen activator.  

PubMed Central

The role of subsite interactions in defining the stringent substrate specificity of tissue-type plasminogen activator (t-PA) has been examined by using an fd phage library that displayed random hexapeptide sequences and contained 2 x 10(8) independent recombinants. Forty-four individual hexapeptides were isolated and identified as improved substrates for t-PA. A peptide containing one of the selected amino acid sequences was cleaved by t-PA 5300 times more efficiently than a peptide that contained the primary sequence of the actual cleavage site in plasminogen. These results suggest that small peptides can mimic determinants that mediate specific proteolysis, emphasize the importance of subsite interactions in determining protease specificity, and have important implications for the evolution of protease cascades. Images Fig. 1 Fig. 2 PMID:7644467

Ding, L; Coombs, G S; Strandberg, L; Navre, M; Corey, D R; Madison, E L

1995-01-01

139

Post-processing of polymer foam tissue scaffolds with high power ultrasound: a route to increased pore interconnectivity, pore size and fluid transport.  

PubMed

The aim of this work is to demonstrate that the structural and fluidic properties of polymer foam tissue scaffolds, post-fabrication but prior to the introduction of cells, can be engineered via exposure to high power ultrasound. Our analysis is supported by measurements of fluid uptake during insonification and imaging of the scaffold microstructure via X-ray computed tomography, scanning electron microscopy and acoustic microscopy. The ultrasonic treatment is performed with a frequency of 30 kHz, average intensities up to 80,000 Wm(-2) and exposure times up to 20 h. The treatment is found to increase the mean pore size by over 10%. More striking is the improvement in fluid uptake: for scaffolds with only 40% water uptake via standard immersion techniques, we can routinely achieve full saturation of the scaffold over approximately one hour of exposure. These desirable modifications occur with negligible loss of scaffold integrity and mass, and are optimized when the ultrasound treatment is coupled to a pre-wetting stage with ethanol. Our findings suggest that high power ultrasound is highly targeted towards flow obstructions in the scaffold architecture, thereby providing an efficient means to promote pore interconnectivity and fluid transport in thick foam tissue scaffolds. PMID:24094193

Watson, N J; Johal, R K; Glover, Z; Reinwald, Y; White, L J; Ghaemmaghami, A M; Morgan, S P; Rose, F R A J; Povey, M J W; Parker, N G

2013-12-01

140

Anterior thigh composition measured using ultrasound imaging to quantify relative thickness of muscle and non-contractile tissue: a potential biomarker for musculoskeletal health.  

PubMed

This study aimed to use ultrasound imaging to provide objective data on the effects of ageing and gender on relative thickness of quadriceps muscle and non-contractile tissue thickness (subcutaneous fat, SF, combined with perimuscular fascia). In 136 healthy males and females (aged 18-90?years n = 63 aged 18-35?years; n = 73 aged 65-90) images of the anterior thigh (dominant) were taken in relaxed supine using B-mode ultrasound imaging. Thickness of muscle, SF and perimuscular fascia were measured, and percentage thickness of total anterior thigh thickness calculated. Independent t-tests compared groups. Correlation between tissue thickness and BMI was examined using Pearson's coefficient. Muscle thickness was: 39? ± ?8?mm in young males, 29? ± ?6?mm in females, 25? ± ?4?mm in older males and 20? ± ?5?mm in females. Percentage muscle to thigh thickness was greater in young participants (p = 0.001). Percentage SF and fascia was 17? ± ?6% in young and 26? ± ?8% in older males, 32? ± ?7% in young and 44? ± ?7% in older females. BMI was similar for age and correlated moderately with non-contractile tissue (r = 0.54; p < 0.001) and poorly with muscle (r = -0.01; p = 0.93). In conclusion, this novel application of ultrasound imaging as a simple and rapid means of assessing thigh composition (relative thickness of muscle and non-contractile tissue) may help inform health status, e.g. in older people at risk of frailty and loss of mobility, and aid monitoring effects of weight loss or gain, deconditioning and exercise. PMID:25243984

Agyapong-Badu, Sandra; Warner, Martin; Samuel, Dinesh; Narici, Marco; Cooper, Cyrus; Stokes, Maria

2014-10-01

141

Opto-acoustic diagnostics of the thermal action of high-intensity focused ultrasound on biological tissues: the possibility of its applications and model experiments  

SciTech Connect

The possibility of using the opto-acoustic (OA) method for monitoring high-intensity ultrasonic therapy is studied. The optical properties of raw and boiled liver samples used as the undamaged model tissue and tissue destroyed by ultrasound, respectively, are measured. Experiments are performed with samples consisting of several alternating layers of raw and boiled liver of different thickness. The position and transverse size of the thermal lesion were determined from the temporal shape of the OA signals. The results of measurements are compared with the real size and position of the thermal lesion determined from the subsequent cuts of the sample. It is shown that the OA method permits the diagnostics of variations in biological tissues upon ultrasonic therapy. (special issue devoted to multiple radiation scattering in random media)

Khokhlova, Tanya D; Pelivanov, Ivan M; Solomatin, Vladimir S; Karabutov, Aleksander A [International Laser Center, M. V. Lomonosov Moscow State University, Moscow (Russian Federation); Sapozhnikov, Oleg A [Department of Physics, M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

2006-12-31

142

Ultrasound thermometry in hyperthermia  

Microsoft Academic Search

A hyperthermia thermometry system using an ultrasound nonlinear effect caused by superposed pulses was developed. A feasibility study was made to obtain temperature mapping of tissue phantoms and of anesthetized pigs heated by an ultrasound applicator. The thermometry system consists of a mechanical sector scanner and a mainframe with a color monitor. The distribution of the temperature rise is calculated

S. Ueno; M. Hashimoto; H. Fukukita; T. Yano

1990-01-01

143

Is tissue harmonic ultrasound imaging (THI) of the prostatic urethra and rectum superior to brightness (B) mode imaging? An observer study.  

PubMed

Quality ultrasound images are an essential part of prostate brachytherapy procedure. The authors have previously reported that tissue harmonic ultrasound images (THI) are superior to brightness (B) mode for the prostate. The objective of the current study was to compare both imaging modes for visualization of the prostatic urethra and rectum. B and THI mode transrectal ultrasound images were acquired for ten patients. The prostatic urethra and rectal wall were contoured by a radiation oncologist (RO) and five observers on randomly presented images. The contours on one patient were repeated four additional times by four observers. All the images were qualitatively scored using a five-level Likert scale. The values of the Pearson product-moment correlation coefficients showed that the observers were in close agreement with the RO. Two sample paired student t-test showed that the rectum volumes with THI were significantly smaller than B-mode, but no significant difference for urethra. Two-factor analysis of variances showed significant observer variability in defining the rectum and urethra in both imaging modes. Observer consistency of the rectum volumes, estimated by standard deviations as percentages of means was significantly improved for THI. The Likert scale based qualitative assessment supported quantitative observations. The significant improvement in image quality of the prostate (reported previously) and rectum with THI may offer better-quality treatment plans for prostate brachytherapy and potential improvement in local control. PMID:24792688

Sandhu, Gurpreet K; Angyalfi, Steve; Dunscombe, Peter B; Khan, Rao F

2014-09-01

144

Ultrasound-based subject-specific parameters improve fascicle behaviour estimation in Hill-type muscle model.  

PubMed

The estimation of muscle fascicle behaviour is decisive in a Hill-type model as they are related to muscle force by the force-length-velocity relationship and the tendon force-strain relationship. This study was aimed at investigating the influence of subject-specific tendon force-strain relationship and initial fascicle geometry (IFG) on the estimation of muscle forces and fascicle behaviour during isometric contractions. Ultrasonography was used to estimate the in vivo muscle fascicle behaviour and compare the muscle fascicle length and pennation angle estimated from the Hill-type model. The calibration-prediction process of the electromyography-driven model was performed using generic or subject-specific tendon definition with or without IFG as constraint. The combination of subject-specific tendon definition and IFG led to muscle fascicle behaviour closer to ultrasound data and significant lower forces of the ankle dorsiflexor and plantarflexor muscles compared to the other conditions. Thus, subject-specific ultrasound measurements improve the accuracy of Hill-type models on muscle fascicle behaviour. PMID:23520994

Gerus, Pauline; Rao, Guillaume; Berton, Eric

2015-02-01

145

High intensity focused ultrasound (HIFU) and ethanol induced tissue ablation: Thermal lesion volume and temperature ex vivo  

NASA Astrophysics Data System (ADS)

HIFU is the upcoming technology for noninvasive or minimally invasive tumor ablation via the localized acoustic energy deposition at the focal region within the tumor target. The presence of cavitation bubbles had been shown to improve the therapeutic effect of HIFU. In this study, we have investigated the effect of HIFU on temperature rise and cavitation bubble activity in ethanol-treated porcine liver and kidney tissues. We have also explored changes in the viability and proliferation rate of HepG2, SW1376, and FB1 cancer cells with their exposure to ethanol and HIFU. Tissues were submerged in 95% ethanol for five hours and then exposed to HIFU generated by a 1.1 MHz transducer or injected into focal spot before HIFU exposure. Cavitation events were measured by a passive cavitation detection technique for a range of acoustic power from 1.17 W to 20.52 W. The temperature around the focal zone was measured by type K or type E thermocouples embedded in the samples. In experiments with cancer cells, 2.7 millions cells were treated with concentration of ethanol at concentration 2%, 4%, 10%, 25%, and 50% and the cell were exposed to HIFU with power of 2.73 W, 8.72 W, and 12.0 W for 30 seconds. Our data show that the treatment of tissues with ethanol reduces the threshold power for inertial cavitation and increases the temperature rise. The exposure of cancer cells to various HIFU power only showed a higher number of viable cells 24 to 72 hours after HIFU exposure. On the other hand, both the viability and proliferation rate were significantly decreased in cells treated with ethanol and then HIFU at 8.7 W and 12.0 W even at ethanol concentration of 2 and 4 percent. In conclusion, the results of our study indicate that percutaneous ethanol injection (PEI) and HIFU have a synergistic effect on cancer cells ablation.

Hoang, Nguyen Hai

146

Quantification of petroleum-type hydrocarbons in avian tissue  

USGS Publications Warehouse

Summary: Methods were developed for the analysis of 16 hydrocarbons in avian tissue. Mechanical extraction with pentane was followed by clean-up on Florisil and Silicar. Residues were determined by gas--liquid chromatography and gas-liquid, chromatography-mass spectrometry. The method was applied to the analysis of liver, kidney, fat, and brain tissue of mallard ducks (Anas platyrhynchos) fed a mixture of hydrocarbons. Measurable concentrations of all compounds analyzed were present in all tissues except brain. Highest concentrations were in fat.

Gay, M.L.; Belisle, A.A.; Patton, J.F.

1980-01-01

147

Femtosecond-assisted preparation of donor tissue for Boston type 1 keratoprosthesis  

PubMed Central

We describe a technique for femtosecond laser-assisted preparation of donor tissue for Boston type 1 keratoprosthesis to provide accurate double punching of the donor tissue for optimized alignment in the visual axis. The technique was reproducibly performed in four donor corneas mounted in an artificial anterior chamber. This technique can provide optically centered donor tissue with smooth trephinated edges. PMID:21845027

Moshirfar, Majid; Neuffer, Marcus C; Kinard, Krista; Lependu, Monette T; Sikder, Shameema

2011-01-01

148

Femtosecond-assisted preparation of donor tissue for Boston type 1 keratoprosthesis.  

PubMed

We describe a technique for femtosecond laser-assisted preparation of donor tissue for Boston type 1 keratoprosthesis to provide accurate double punching of the donor tissue for optimized alignment in the visual axis. The technique was reproducibly performed in four donor corneas mounted in an artificial anterior chamber. This technique can provide optically centered donor tissue with smooth trephinated edges. PMID:21845027

Moshirfar, Majid; Neuffer, Marcus C; Kinard, Krista; Lependu, Monette T; Sikder, Shameema

2011-01-01

149

Distinctive types of leaf tissue damage influence nutrient supply to growing tissues within seagrass shoots  

Microsoft Academic Search

Herbivory is now recognized as an important structuring agent in seagrass meadows but the attack pattern and tissue damage\\u000a of consumers are highly variable. Nutritional preferences of herbivores and\\/or easy access to resources may cause differences\\u000a in biomass loss among tissues that damage the plant in functionally distinctive ways. The two main Mediterranean herbivores,\\u000a the fish Sarpa salpa (L.) and

Patricia PradoCatherine; Catherine J. Collier; Javier Romero; Teresa Alcoverro

2011-01-01

150

3D conformal MRI-controlled transurethral ultrasound prostate therapy: validation of numerical simulations and demonstration in tissue-mimicking gel phantoms.  

PubMed

MRI-controlled transurethral ultrasound therapy uses a linear array of transducer elements and active temperature feedback to create volumes of thermal coagulation shaped to predefined prostate geometries in 3D. The specific aims of this work were to demonstrate the accuracy and repeatability of producing large volumes of thermal coagulation (>10 cc) that conform to 3D human prostate shapes in a tissue-mimicking gel phantom, and to evaluate quantitatively the accuracy with which numerical simulations predict these 3D heating volumes under carefully controlled conditions. Eleven conformal 3D experiments were performed in a tissue-mimicking phantom within a 1.5T MR imager to obtain non-invasive temperature measurements during heating. Temperature feedback was used to control the rotation rate and ultrasound power of transurethral devices with up to five 3.5 × 5 mm active transducer elements. Heating patterns shaped to human prostate geometries were generated using devices operating at 4.7 or 8.0 MHz with surface acoustic intensities of up to 10 W cm(-2). Simulations were informed by transducer surface velocity measurements acquired with a scanning laser vibrometer enabling improved calculations of the acoustic pressure distribution in a gel phantom. Temperature dynamics were determined according to a FDTD solution to Pennes' BHTE. The 3D heating patterns produced in vitro were shaped very accurately to the prostate target volumes, within the spatial resolution of the MRI thermometry images. The volume of the treatment difference falling outside ± 1 mm of the target boundary was, on average, 0.21 cc or 1.5% of the prostate volume. The numerical simulations predicted the extent and shape of the coagulation boundary produced in gel to within (mean ± stdev [min, max]): 0.5 ± 0.4 [-1.0, 2.1] and -0.05 ± 0.4 [-1.2, 1.4] mm for the treatments at 4.7 and 8.0 MHz, respectively. The temperatures across all MRI thermometry images were predicted within -0.3 ± 1.6 °C and 0.1 ± 0.6 °C, inside and outside the prostate respectively, and the treatment time to within 6.8 min. The simulations also showed excellent agreement in regions of sharp temperature gradients near the transurethral and endorectal cooling devices. Conformal 3D volumes of thermal coagulation can be precisely matched to prostate shapes with transurethral ultrasound devices and active MRI temperature feedback. The accuracy of numerical simulations for MRI-controlled transurethral ultrasound prostate therapy was validated experimentally, reinforcing their utility as an effective treatment planning tool. PMID:21030751

Burtnyk, Mathieu; N'Djin, William Apoutou; Kobelevskiy, Ilya; Bronskill, Michael; Chopra, Rajiv

2010-11-21

151

Hip Ultrasound  

MedlinePLUS

... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

152

Ultrasound - Breast  

MedlinePLUS

... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

153

Abdominal Ultrasound  

MedlinePLUS

... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

154

Scrotal Ultrasound  

MedlinePLUS

... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

155

Ultrasound -- Vascular  

MedlinePLUS

... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

156

valuation of the in vivo contrast using fast spin echo MRI sequences between tissues and thermal lesions in rabbit produced by high intensity focused ultrasound  

NASA Astrophysics Data System (ADS)

In this paper the goal was to measure the contrast to noise ratio (CNR) of fast spin echo (FSE) magnetic resonance imaging (MRI) sequences in detecting thermal lesions created by high intensity focused ultrasound (HIFU) in rabbit kidney, liver, heart, and brain and lamb pancreas. A spherically focused transducer was used which is navigated inside MRI by a custom made positioning device. A simple simulation model was developed which predicts the CNR for the two FSE MRI sequences. The maximum contrast measured with T1-W FSE ranges from 10 to 25. For all 5 tissues of interest if one uses TR between 400 and 500 ms the contrast is maximized. The T1, and T2 value of lesion depends strongly on the host tissue and is always lower than the host tissue. The greater the difference in T1 value, the greater the CNR. The simulated model for predicting the CNR was proven successful. The CNR measured with T2-W FSE varies between 12 and 15 for all 5 tissues. With T2-W FSE if one uses TE between 40 and 50 ms, the contrast is maximized.

Damianou, Christakis; Ioannides, Kleanthis; Hadjisavas, Venediktos; Milonas, Nikos; Couppis, Andreas; Iosif, Demitris

2010-03-01

157

Topographical Control of Ocular Cell Types for Tissue Engineering  

PubMed Central

Visual impairment affects over 285 million people worldwide and has a major impact on an individual’s quality of life. Tissue engineering has the potential to increase quality of life for many of these patients by preventing vision loss or restoring vision using cell-based therapies. However, these strategies will require an understanding of the microenvironmental factors that influence cell behavior. The eye is a well-organized organ whose structural complexity is essential for proper function. Interactions between ocular cells and their highly ordered extracellular matrix are necessary for maintaining key tissue properties including corneal transparency and retinal lamination. Therefore, it is not surprising that culturing these cells in vitro on traditional flat substrates result in irregular morphology. Instead, topographically patterned biomaterials better mimic native extracellular matrix and have been shown to elicit in vivo-like morphology and gene expression which is essential for tissue engineering. Herein we review multiple methods for producing well-controlled topography and discuss optimal biomaterial scaffold design for cells of the cornea, retina, and lens. PMID:23744715

McHugh, Kevin J.; Saint-Geniez, Magali; Tao, Sarah L.

2014-01-01

158

Cell type-specific gene expression differences in complex tissues.  

PubMed

We describe cell type-specific significance analysis of microarrays (csSAM) for analyzing differential gene expression for each cell type in a biological sample from microarray data and relative cell-type frequencies. First, we validated csSAM with predesigned mixtures and then applied it to whole-blood gene expression datasets from stable post-transplant kidney transplant recipients and those experiencing acute transplant rejection, which revealed hundreds of differentially expressed genes that were otherwise undetectable. PMID:20208531

Shen-Orr, Shai S; Tibshirani, Robert; Khatri, Purvesh; Bodian, Dale L; Staedtler, Frank; Perry, Nicholas M; Hastie, Trevor; Sarwal, Minnie M; Davis, Mark M; Butte, Atul J

2010-04-01

159

Cranial Ultrasound/Head Ultrasound  

MedlinePLUS

... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

160

Type of MRI contrast, tissue gadolinium, and fibrosis.  

PubMed

It has been presupposed that the thermodynamic stability constant (Ktherm) of gadolinium-based MRI chelates relate to the risk of precipitating nephrogenic systemic fibrosis. The present study compared low-Ktherm gadodiamide with high-Ktherm gadoteridol in cultured fibroblasts and rats with uninephrectomies. Gadolinium content was assessed using scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy in paraffin-embedded tissues. In vitro, fibroblasts demonstrated dose-dependent fibronectin generation, transforming growth factor-? production, and expression of activated myofibroblast stress fiber protein ?-smooth muscle actin. There were negligible differences with respect to toxicity or proliferation between the two contrast agents. In the rodent model, gadodiamide treatment led to greater skin fibrosis and dermal cellularity than gadoteridol. In the kidney, both contrast agents led to proximal tubule vacuolization and increased fibronectin accumulation. Despite large detectable gadolinium signals in the spleen, skin, muscle, and liver from the gadodiamide-treated group, contrast-induced fibrosis appeared to be limited to the skin and kidney. These findings support the hypothesis that low-Ktherm chelates have a greater propensity to elicit nephrogenic systemic fibrosis and demonstrate that certain tissues are resistant to these effects. PMID:25100280

Do, Catherine; Barnes, Jeffrey L; Tan, Chunyan; Wagner, Brent

2014-10-01

161

Computational study on the propagation of strongly focused nonlinear ultrasound in tissue with rib-like structures.  

PubMed

The presence of a rib cage is a significant hindrance to the potential applications of focused ultrasound as a noninvasive extracorporeal surgery modality for various internal organs. Here the influence of ribs on the propagation of strongly focused high-intensity nonlinear ultrasound beam inside the body is studied. Based on the spheroidal beam equation, a three-dimensional numerical algorithm is developed to solve the nonlinear acoustic field generated by a focused ultrasonic transducer with a large aperture angle. Idealized ribs, of rectangular cross sectional, with high absorption and impedance, and various dimensions, are used to simulate human anatomical configurations. The changes in the spatial distribution of acoustic intensity and the reduction of the acoustic pressure amplitude and heat deposition rate due to the presence of "ribs" are investigated. It is somewhat surprising that in some cases, the axial peak positions shift less than 2?mm and more than 80% of the sound energy can propagate through the space of the rib cage in the strongly focused sound field. This study also includes quantitative analyses of the effects of different rib configurations and transducers of various f-numbers. The results can be used as reference information for further study and clinical applications. PMID:23927211

Lin, Jiexing; Liu, Xiaozhou; Gong, Xiufen; Ping, Zihong; Wu, Junru

2013-08-01

162

On the KZK-type equation for modulated ultrasound fields Egor Dontsov and Bojan Guzina  

E-print Network

and the carrier frequency is o(1). The model is relevant to a variety of diagnostic techniques where the acoustic techniques that make use of the acoustic radiation force [1] such as vibro-acoustography [2], shear wave for local tissue interrogation in terms of its shear stiffness properties [2, 3, 4, 8, 9]. Here it is noted

Guzina, Bojan

163

The role of acoustic nonlinearity in tissue heating behind a rib cage using a high-intensity focused ultrasound phased array  

NASA Astrophysics Data System (ADS)

The goal of this study was to investigate theoretically the effects of nonlinear propagation in a high-intensity focused ultrasound (HIFU) field produced by a therapeutic phased array and the resultant heating of tissue behind a rib cage. Three configurations of focusing were simulated: in water, in water with ribs in the beam path and in water with ribs backed by a layer of soft tissue. The Westervelt equation was used to model the nonlinear HIFU field, and a 1 MHz phased array consisting of 254 circular elements was used as a boundary condition to the model. The temperature rise in tissue was modelled using the bioheat equation, and thermally necrosed volumes were calculated using the thermal dose formulation. The shapes of lesions predicted by the modelling were compared with those previously obtained in in vitro experiments at low-power sonications. Intensity levels at the face of the array elements that corresponded to the formation of high-amplitude shock fronts in the focal region were determined as 10 W cm-2 in the free field in water and 40 W cm-2 in the presence of ribs. It was shown that exposures with shocks provided a substantial increase in tissue heating, and its better spatial localization in the main focal region only. The relative effects of overheating ribs and splitting of the focus due to the periodic structure of the ribs were therefore reduced. These results suggest that utilizing nonlinear propagation and shock formation effects can be beneficial for inducing confined HIFU lesions when irradiating through obstructions such as ribs. Design of compact therapeutic arrays to provide maximum power outputs with lower intensity levels at the elements is necessary to achieve shock wave regimes for clinically relevant sonication depths in tissue.

Yuldashev, Petr V.; Shmeleva, Svetlana M.; Ilyin, Sergey A.; Sapozhnikov, Oleg A.; Gavrilov, Leonid R.; Khokhlova, Vera A.

2013-04-01

164

Tissue Fibrinolytic Activity in Different Types of Varicose Veins  

Microsoft Academic Search

The fibrinolytic activity of the venous wall was investigated by using Todd's technique 1 in 92 patients with different types of varicosis.A control group consisted of 19 patients with apparently normal superficial veins who had had a saphenectomy prior to an aortocoronary bypass operation. Fibrinolytic activity was mainly localized in the adventitia of varicose and nor mal veins. It significantly

Viola Hach; Monika Fink; Norbert Blees; Inge Scharrer

1986-01-01

165

Tissue preconditioning may explain concentric lesions in Balo's type of multiple sclerosis  

Microsoft Academic Search

Summary Lesions of Balo´'s concentric sclerosis are characterized by alternating layers of myelinated and demyelinated tissue. The reason for concentric demyelination in this variant of multiple sclerosis is unclear. In the present study we investigated the immunopathology in autopsy tissue of 14 patients with acute multiple sclerosis or fulminant exacerbations of chronic multiple sclerosis with Balo´-type lesions in the CNS,

Christine Stadelmann; Sam Ludwin; Takeshi Tabira; Andras Guseo; Claudia F. Lucchinetti; Lorant Leel-Ossy; Artemio T. Ordinario; Wolfgang Bruck; Hans Lassmann

2005-01-01

166

Section-thickness profiling for brachytherapy ultrasound guidance  

Microsoft Academic Search

Purpose: Ultrasound (US) elevation beamwidth causes a certain type of image artifact around the anechoic areas of the tissue. It is generally assumed that the US image is of zero thickness, which contradicts the fact that the acoustic beam can only be mechanically focused at a depth resulting in a finite, non-uniformed elevation beamwidth. We suspect that elevation beamwidth artifacts

Mohammad Peikari; Thomas K. Chen; Everette C. Burdette; Gabor Fichtinger

2011-01-01

167

21 CFR 1271.85 - What donor testing is required for different types of cells and tissues?  

Code of Federal Regulations, 2010 CFR

...testing is required for different types of cells and tissues? 1271.85 Section 1271...THE FOOD AND DRUG ADMINISTRATION HUMAN CELLS, TISSUES, AND CELLULAR AND TISSUE-BASED...testing is required for different types of cells and tissues? (a) All donors...

2010-04-01

168

21 CFR 1271.85 - What donor testing is required for different types of cells and tissues?  

Code of Federal Regulations, 2011 CFR

...testing is required for different types of cells and tissues? 1271.85 Section 1271...THE FOOD AND DRUG ADMINISTRATION HUMAN CELLS, TISSUES, AND CELLULAR AND TISSUE-BASED...testing is required for different types of cells and tissues? (a) All donors...

2011-04-01

169

Cell-Type-Specific Genome-wide Expression Profiling after Laser Capture Microdissection of Living Tissue  

SciTech Connect

The purpose of this technical feasibility study was to develop and evaluate robust microgenomic tools for investigations of genome-wide expression of very small numbers of cells isolated from whole tissue sections. Tissues contain large numbers of cell-types that play varied roles in organ function and responses to endogenous and exogenous toxicants whether bacterial, viral, chemical or radiation. Expression studies of whole tissue biopsy are severely limited because heterogeneous cell-types result in an averaging of molecular signals masking subtle but important changes in gene expression in any one cell type(s) or group of cells. Accurate gene expression analysis requires the study of specific cell types in their tissue environment but without contamination from surrounding cells. Laser capture microdissection (LCM) is a new technology to isolate morphologically distinct cells from tissue sections. Alternative methods are available for isolating single cells but not yet for their reliable genome-wide expression analyses. The tasks of this feasibility project were to: (1) Develop efficient protocols for laser capture microdissection of cells from tissues identified by antibody label, or morphological stain. (2) Develop reproducible gene-transcript analyses techniques for single cell-types and determine the numbers of cells needed for reliable genome-wide analyses. (3) Validate the technology for epithelial and endothelial cells isolated from the gastrointestinal tract of mice.

Marchetti, F; Manohar, C F

2005-02-09

170

Adaptive Thermal Therapy using Planar Ultrasound Transducers with Real-time MR Temperature Feedback: Demonstration in Gel Phantoms and Ex-vivo Tissues  

NASA Astrophysics Data System (ADS)

MRI-guided transurethral ultrasound therapy offers a minimally invasive approach for the treatment of localized prostate cancer. The main goal of this study was to evaluate active temperature feedback on a clinical 1.5T MR imager to control conformal thermal therapy. MR thermometry was performed during heating in both thermal gel phantoms and ex-vivo tissue with a single-element transurethral heating applicator. The applicator rotation rate and power were controlled based on MRI-temperature measurements. The influence of a cooling gradient (to simulate cooling of the rectum or urethra) was also investigated in gel phantoms. The 55°C isotherm generated during heating closely matched the targeted prostate shape, with an average distance error of 0.9 mm ± 0.4 mm in turkey breasts, 1.3 mm ± 0.5 mm in gel phantoms without rectal cooling and 1.4 mm ± 0.6 mm in gel phantoms with rectal cooling. Accurate, MRI-guided, active feedback has been successfully demonstrated experimentally and has the capability to adjust for unpredictable and varying tissue properties during the treatment.

Tang, Kee; Choy, Vanessa; Chopra, Rajiv; Bronskill, Michael

2007-05-01

171

In vivo characterization of tissue thermal properties of the kidney during local hyperthermia induced by MR-guided high-intensity focused ultrasound.  

PubMed

The purpose of this study was to evaluate quantitatively in vivo the tissue thermal properties during high-intensity focused ultrasound (HIFU) heating. For this purpose, a total of 52 localized sonications were performed in the kidneys of six pigs with HIFU monitored in real time by volumetric MR thermometry. The kidney perfusion was modified by modulation of the flow in the aorta by insertion of an inflatable angioplasty balloon. The resulting temperature data were analyzed using the bio-heat transfer model in order to validate the model under in vivo conditions and to estimate quantitatively the absorption (?), thermal diffusivity (D) and perfusion (w(b)) of renal tissue. An excellent correspondence was observed between the bio-heat transfer model and the experimental data. The absorption and thermal diffusivity were independent of the flow, with mean values (± standard deviation) of 20.7 ± 5.1 mm(3) K J(-1) and 0.23 ± 0.11 mm(2) s(-1), respectively, whereas the perfusion decreased significantly by 84% (p < 0.01) with arterial flow (mean values of w(b) of 0.06 ± 0.02 and 0.008 ± 0.007 mL(-1) mL s(-1)), as predicted by the model. The quantitative analysis of the volumetric temperature distribution during nondestructive HIFU sonication allows the determination of the thermal parameters, and may therefore improve the quality of the planning of noninvasive therapy with MR-guided HIFU. PMID:21834004

Cornelis, François; Grenier, Nicolas; Moonen, Chrit T; Quesson, Bruno

2011-08-01

172

Technical Advances in Endoscopic Ultrasound (EUS)-Guided Tissue Acquisition for Pancreatic Cancers: How Can We Get the Best Results with EUS-Guided Fine Needle Aspiration?  

PubMed Central

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is one of the least invasive and most effective modality in diagnosing pancreatic adenocarcinoma in solid pancreatic lesions, with a higher diagnostic accuracy than cystic tumors. EUS-FNA has been shown to detect tumors less than 3 mm, due to high spatial resolution allowing the detection of very small lesions and vascular invasion, particularly in the pancreatic head and neck, which may not be detected on transverse computed tomography. Furthermore, this minimally invasive procedure is often ideal in the endoscopic procurement of tissue in patients with unresectable tumors. While EUS-FNA has been increasingly used as a diagnostic tool, most studies have collectively looked at all primary pancreatic solid lesions, including lymphomas and pancreatic neuroendocrine neoplasms, whereas very few studies have examined the diagnostic utility of EUS-FNA of pancreatic ductal carcinoma only. As with any novel and advanced endoscopic procedure that may incorporate several practices and approaches, endoscopists have adopted diverse techniques to improve the tissue procurement practice and increase diagnostic accuracy. In this article, we present a review of literature to date and discuss currently practiced EUS-FNA technique, including indications, technical details, equipment, patient selection, and diagnostic accuracy. PMID:24143320

Kedia, Prashant; Gaidhane, Monica

2013-01-01

173

Contrast-enhanced, real-time volumetric ultrasound imaging of tissue perfusion: preliminary results in a rabbit model of testicular torsion  

NASA Astrophysics Data System (ADS)

Contrast-enhanced ultrasound (US) imaging is potentially applicable to the clinical investigation of a wide variety of perfusion disorders. Quantitative analysis of perfusion is not widely performed, and is limited by the fact that data are acquired from a single tissue plane, a situation that is unlikely to accurately reflect global perfusion. Real-time perfusion information from a tissue volume in an experimental rabbit model of testicular torsion was obtained with a two-dimensional matrix phased array US transducer. Contrast-enhanced imaging was performed in 20 rabbits during intravenous infusion of the microbubble contrast agent Definity® before and after unilateral testicular torsion and contralateral orchiopexy. The degree of torsion was 0° in 4 (sham surgery), 180° in 4, 360° in 4, 540° in 4, and 720° in 4. An automated technique was developed to analyze the time history of US image intensity in experimental and control testes. Comparison of mean US intensity rate of change and of ratios between mean US intensity rate of change in experimental and control testes demonstrated good correlation with testicular perfusion and mean perfusion ratios obtained with radiolabeled microspheres, an accepted 'gold standard'. This method is of potential utility in the clinical evaluation of testicular and other organ perfusion.

Paltiel, H. J.; Padua, H. M.; Gargollo, P. C.; Cannon, G. M., Jr.; Alomari, A. I.; Yu, R.; Clement, G. T.

2011-04-01

174

OPTIMIZATION OF THE CONTRAST TISSUE RATIO IN ULTRA-SOUND CONTRAST IMAGING BY AN ADAPTIVE TRANSMIT FRE-  

E-print Network

. We show, through experiments, that our adaptive imaging technique increases the CTR of 2 dB compared that maximizes the contrast tissue ratio (CTR). The method is proposed with the contrast imaging and the harmonic way. 2. Methods and Materials 2.1 Methods The optimization aims to maximize the power

Boyer, Edmond

175

Ultrasound mediated delivery of drugs and genes to solid tumors  

PubMed Central

It has long been shown that therapeutic ultrasound can be used effectively to ablate solid tumors, and a variety of cancers are presently being treated in the clinic using these types of ultrasound exposures. There is, however, an ever-increasing body of preclinical literature that demonstrates how ultrasound energy can also be used non-destructively for increasing the efficacy of drugs and genes for improving cancer treatment. In this review, a summary of the most important ultrasound mechanisms will be given with a detailed description of how each one can be employed for a variety of applications. This includes the manner by which acoustic energy deposition can be used to create changes in tissue permeability for enhancing the delivery of conventional agents, as well as for deploying and activating drugs and genes via specially tailored vehicles and formulations. PMID:18474406

Frenkel, Victor

2008-01-01

176

Immunohistochemical localization of short chain cartilage collagen (type X) in avian tissues  

Microsoft Academic Search

Monoclonal antibodies were produced against the recently described short chain cartilage collagen (type X collagen), and one (AC9) was extensively characterized and used for immunohistochemical localization studies on chick tissues. By competition enzyme-linked immunosorbent assay, antibody AC9 was observed to bind to an epitope within the helical domain of type X collagen and did not react with the other collagen

THOMAS M. SCHMID; THOMAS F. LINSENMAYER

1985-01-01

177

One-pot three-component Mannich-type reactions using Sulfamic acid catalyst under ultrasound irradiation  

Microsoft Academic Search

Sulfamic acid (NH2SO3H, SA) was used as an efficient, inexpensive, non-toxic and recyclable green catalyst for the ultrasound-assisted one-pot Mannich reaction of aldehydes with ketones and amines. This ultrasound protocol has advantages of high yield, mild condition, no environmental pollution, and simple work-up procedures. Most importantly, ?-aminocarbonyl compounds with ortho-substituted aromatic amines are obtained in acceptable to good yields by

Hongyao Zeng; Hua Li; Huawu Shao

2009-01-01

178

Obstetrical Ultrasound  

MedlinePLUS

... For most ultrasound exams, you will be positioned lying face-up on an examination table that can ... ovaries. Transvaginal ultrasound is usually performed with you lying on your back, possibly with your feet in ...

179

Ultrasound Characteristics of Thyroglossal Duct Anomalies  

Microsoft Academic Search

The purpose of this study was to determine the value of ultrasound examination in the diagnosis of thyroglossal duct anomalies. The ultrasound and palpation findings in 24 patients with a thyroglossal duct anomaly were reviewed. Cysts, tracts and ectopic thyroid tissue appeared to produce a characteristic ultrasound pattern in most cases. This study includes 5 patients with non-symptomatic lesions which

Robert J. Baatenburg de Jong; Robert J. Rongen; Johan S. Laméris; Paul Knegt; Carel D. A. Verwoerd

1993-01-01

180

Thyroid ultrasound  

PubMed Central

Thyroid ultrasonography has established itself as a popular and useful tool in the evaluation and management of thyroid disorders. Advanced ultrasound techniques in thyroid imaging have not only fascinated the radiologists but also attracted the surgeons and endocrinologists who are using these techniques in their daily clinical and operative practice. This review provides an overview of indications for ultrasound in various thyroid diseases, describes characteristic ultrasound findings in these diseases, and illustrates major diagnostic pitfalls of thyroid ultrasound. PMID:23776892

Chaudhary, Vikas; Bano, Shahina

2013-01-01

181

Ultrasound Techniques for Space Applications  

NASA Technical Reports Server (NTRS)

Ultrasound has proven to be a safe non-invasive technique for imaging organs and measuring cardiovascular function. It has unique advantages for application to problems with man in space including evaluation of cardiovascular function both in serial studies and during critical operations. In addition, specialized instrumentation may be capable of detecting the onset of decompression sickness during EVA activities. A spatial location and three-dimensional reconstruction system is being developed to improve the accuracy and reproducibility for serial comparative ultrasound studies of cardiovascular function. The three-dimensional method permits the acquisition of ultrasonic images from many views that can be recombined into a single reconstruction of the heart or vasculature. In addition to conventional imaging and monitoring systems, it is sometimes necessary or desirable to develop instrumentation for special purposes. One example of this type of development is the design of a pulsed-Doppler system to monitor cerebral blood flow during critical operations such as re-entry. A second example is the design of a swept-frequency ultrasound system for the detection of bubbles in the circulatory system and/or soft tissues as an early indication of the onset of decompression sickness during EVA activities. This system exploits the resonant properties of bubbles and can detect both fundamental and second harmonic emissions from the insonified region.

Rooney, James A.

1985-01-01

182

Evaluation of serial changes in tissue characteristics during statin-induced plaque regression using virtual histology-intravascular ultrasound studies.  

PubMed

Treatment of all coronary arteries is important to improve the prognosis of acute coronary syndrome after early reperfusion of the culprit lesion. Early statin treatment has been reported to cause regression of plaques away from the site of the culprit lesion in patients with acute coronary syndrome. However, the precise mechanism of coronary plaque regression is not well understood. We studied the effects of statins on the regression of coronary plaques away from the culprit lesions in 120 patients with acute coronary syndrome. We used virtual histology-intravascular ultrasound studies to evaluate nonpercutaneous coronary intervention lesions at admission and short-term (2 to 3 weeks) and medium-term (8 to 10 months) follow-up. According to the medium-term evaluation findings, the subjects were divided into 2 groups: a plaque regression group (n = 94) and a plaque progression group (n = 26). In the regression group, the fibrofatty component had decreased at the short-term (-20.0% vs baseline) and had decreased further at the medium-term (-26.7%) evaluations. The fibrous component had also decreased at the short-term (-5.1%) and medium-term (-8.5%) evaluations. In contrast, the necrotic core component showed a tendency to increase in the short term (+12.5%) but then decreased at the medium-term evaluation (-6.3%). In the progression group, the fibrofatty and fibrous components had increased at the short-term (+37.5%, +11.3%) and medium-term (+50.5%, +13.2%) evaluations; however, the necrotic core had decreased at the short-term (-19.0%) and medium-term (-23.8%) evaluations. In conclusion, regarding the course of coronary plaque regression by statin therapy, the plaques began to reduce the volume of fibrofatty and fibrous components in the early phase, associated with a transiently increased necrotic core component. Furthermore, even in the case of plaque progression, statins caused a reduction in the necrotic core. PMID:23411102

Taguchi, Isao; Oda, Kazuhiko; Yoneda, Shuichi; Kageyama, Michiya; Kanaya, Tomoaki; Toyoda, Shigeru; Abe, Shichiro; Node, Koichi; Inoue, Teruo

2013-05-01

183

The Role of Adipose Tissue and Lipotoxicity in the Pathogenesis of Type 2 Diabetes  

Microsoft Academic Search

The widespread epidemics of obesity and type 2 diabetes mellitus (T2DM) suggest that both conditions are closely linked. An\\u000a increasing body of evidence has shifted our view of adipose tissue from a passive energy depot to a dynamic “endocrine organ”\\u000a that tightly regulates nutritional balance by means of a complex crosstalk of adipocytes with their microenvironment. Dysfunctional\\u000a adipose tissue, particularly

Kenneth Cusi

2010-01-01

184

The effect of medical exercise therapy on a patient with chronic supraspinatus tendinitis. Diagnostic ultrasound--tissue regeneration: a case study.  

PubMed

There is an increased focus on the importance of using active exercise regimes for treating dysfunction in the musculoskeletal system. However, we have little exact knowledge on how to dose and grade exercises or the effect of exercise on the regeneration of low metabolic tissue structures in vivo. This case study deals with both topics and emphasizes the use of exercise only when treating a 73-year-old patient with a 1-year history of shoulder pain. His evaluation indicated chronic supraspinatus syndrome. Different treatment methods had no effect, and medical exercise therapy was tried as a last resort. The patient recovered after 21/2 months with four treatments per week. Diagnostic ultrasound taken before treatment and after a 51/2-month period showed that the supraspinatus tendon had regenerated. These findings are encouraging, supporting the possibility of tendon repair with biomechanical stresses from exercise. To our knowledge, it has never been shown in vivo that it is possible for a low metabolic structure to regenerate using exercise only. Instead of having surgery with an uncertain outcome, today the patient is free of symptoms and living a normal life enjoying his sporting activities nearly 4 years after he finished the treatment. PMID:7849752

Torstensen, T A; Meen, H D; Stiris, M

1994-12-01

185

Assessment of ultrasound-assisted extraction as sample pre-treatment for the measurement of lead isotope ratios in marine biological tissues by multicollector inductively coupled plasma-mass spectrometry  

NASA Astrophysics Data System (ADS)

In this work, ultrasound-assisted extraction (UAE) was evaluated as a sample preparation procedure for lead isotope ratio measurements in marine biological tissues by multicollector inductively coupled plasma-mass spectrometry. 20 mg of marine biological tissue and 1 mL of acid extractant were sonicated for 3 min at 60% ultrasound amplitude. Matrix separation was performed in the supernatant using a chromatographic exchange resin (Sr-Spec™). Total elimination of organic matter was achieved during the separation step. Microwave-assisted digestion and dry-ashing were used for comparative purposes. No significant differences were found in lead isotope ratios at 95% of confidence level. UAE emerges as an advantageous alternative to classical methods for sample preparation owing to its simplicity and rapidity ( i.e. operation steps were reduced), low reagent consumption and low contamination risks.

Costas-Rodríguez, M.; Lavilla, Isela; Bendicho, Carlos

2011-06-01

186

Oncogenic osteomalacia associated with phosphaturic mesenchymal tumour, mixed connective tissue type of the knee.  

PubMed

One of the most unusual and uncommon types of osteomalacia is the oncogenic osteomalacia that is predominantly caused by a soft tissue or bone tumour, mostly by a phosphaturic mesenchymal tumour, mixed connective tissue type (PMTMCT). We report a case of a 27-year-old male presented with complaints of progressive and generalized muscle weakness, bone pains and multiple fractures. Intra-articular PMTMCT of the knee was diagnosed and surgically removed. We describe histopathological features of PMTMCT and review the most recent studies concerning this diagnostic problem. PMID:20200786

Szumera-Cie?kiewicz, Anna; Ptaszy?ski, Konrad; Pawe?as, Andrzej; Rutkowski, Piotr

2009-01-01

187

Ultrasound in analytical chemistry  

Microsoft Academic Search

Ultrasound is a type of energy which can help analytical chemists in almost all their laboratory tasks, from cleaning to detection.\\u000a A generic view of the different steps which can be assisted by ultrasound is given here. These steps include preliminary operations\\u000a usually not considered in most analytical methods (e.g. cleaning, degassing, and atomization), sample preparation being the\\u000a main area

F. Priego Capote; M. D. Luque de Castro

2007-01-01

188

Posttranslational Modifications in Type I Collagen from Different Tissues Extracted from Wild Type and Prolyl 3-Hydroxylase 1 Null Mice*  

PubMed Central

Type I collagen extracted from tendon, skin, and bone of wild type and prolyl 3-hydroxylase 1 (P3H1) null mice shows distinct patterns of 3-hydroxylation and glycosylation of hydroxylysine residues. The A1 site (Pro-986) in the ?1-chain of type I collagen is almost completely 3-hydroxylated in every tissue of the wild type mice. In contrast, no 3-hydroxylation of this proline residue was found in P3H1 null mice. Partial 3-hydroxylation of the A3 site (Pro-707) was present in tendon and bone, but absent in skin in both ?-chains of the wild type animals. Type I collagen extracted from bone of P3H1 null mice shows a large reduction in 3-hydroxylation of the A3 site in both ?-chains, whereas type I collagen extracted from tendon of P3H1 null mice shows little difference as compared with wild type. These results demonstrate that the A1 site in type I collagen is exclusively 3-hydroxylated by P3H1, and presumably, this enzyme is required for the 3-hydroxylation of the A3 site of both ?-chains in bone but not in tendon. The increase in glycosylation of hydroxylysine in P3H1 null mice in bone was found to be due to an increased occupancy of normally glycosylated sites. Despite the severe disorganization of collagen fibrils in adult tissues, the D-period of the fibrils is unchanged. Tendon fibrils of newborn P3H1 null mice are well organized with only a slight increase in diameter. The absence of 3-hydroxyproline and/or the increased glycosylation of hydroxylysine in type I collagen disturbs the lateral growth of the fibrils. PMID:23861401

Pokidysheva, Elena; Zientek, Keith D.; Ishikawa, Yoshihiro; Mizuno, Kazunori; Vranka, Janice A.; Montgomery, Nathan T.; Keene, Douglas R.; Kawaguchi, Tatsuya; Okuyama, Kenji; Bächinger, Hans Peter

2013-01-01

189

Cell-type-specific isolation of ribosome-associated mRNA from complex tissues  

PubMed Central

Gene profiling techniques allow the assay of transcripts from organs, tissues, and cells with an unprecedented level of coverage. However, most of these approaches are still limited by the fact that organs and tissues are composed of multiple cell types that are each unique in their patterns of gene expression. To identify the transcriptome from a single cell type in a complex tissue, investigators have relied upon physical methods to separate cell types or in situ hybridization and immunohistochemistry. Here, we describe a strategy to rapidly and efficiently isolate ribosome-associated mRNA transcripts from any cell type in vivo. We have created a mouse line, called RiboTag, which carries an Rpl22 allele with a floxed wild-type C-terminal exon followed by an identical C-terminal exon that has three copies of the hemagglutinin (HA) epitope inserted before the stop codon. When the RiboTag mouse is crossed to a cell-type-specific Cre recombinase-expressing mouse, Cre recombinase activates the expression of epitope-tagged ribosomal protein RPL22ha, which is incorporated into actively translating polyribosomes. Immunoprecipitation of polysomes with a monoclonal antibody against HA yields ribosome-associated mRNA transcripts from specific cell types. We demonstrate the application of this technique in brain using neuron-specific Cre recombinase-expressing mice and in testis using a Sertoli cell Cre recombinase-expressing mouse. PMID:19666516

Sanz, Elisenda; Yang, Linghai; Su, Thomas; Morris, David R.; McKnight, G. Stanley; Amieux, Paul S.

2009-01-01

190

X-ray scattering for classifying tissue types associated with breast disease  

SciTech Connect

Collagen types I and III can be characterized at the molecular level (at the tens to hundreds of nanometers scale) using small angle x-ray scattering (SAXS). Although collagen fibril structural parameters at this length scale have shown differences between diseased and nondiseased breast tissues, a comprehensive analysis involving a multitude of features with a large (>50) patient cohort has not previously been investigated. Breast tissue samples were excised from 80 patients presenting with either a breast lump or reduction mammoplasty. From these, invasive carcinoma, benign tissue, and normal parenchyma were analyzed. Parameters related to collagen structure, including longitudinal (axial) and lateral (equatorial) features, polar angle features, total scattering intensity, and tissue heterogeneity effects, were extracted from the SAXS patterns and examined. The amplitude of the third-order axial peak and the total scattering intensity (amorphous scatter) showed the most separation between tissue groups and a classification model using these two parameters demonstrated an accuracy of over 95% between invasive carcinoma and mammoplasty patients. Normal tissue taken from disease-free patients (mammoplasty) and normal tissue taken from patients with presence of disease showed significant differences, suggesting that SAXS may provide different diagnostic information from that of conventional histopathology.

Sidhu, Sabeena; Siu, Karen K. W.; Falzon, Gregory; Nazaretian, Simon; Hart, Stewart A.; Fox, Jane G.; Susil, Beatrice J.; Lewis, Robert A. [Monash Centre for Synchrotron Science, and School of Physics, Monash University, Clayton, Victoria 3800 (Australia); School of Science and Technology, University of New England, Armidale, New South Wales 2351 (Australia); Department of Anatomical Pathology, The Royal Women's Hospital, Carlton, Victoria 3053, Australia, Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria 3800, Australia, and Department of Pathology, Monash Medical Centre, Clayton, Victoria 3168 (Australia); Department of Surgery, Monash Medical Centre, Clayton, Victoria 3168, Australia and Monash Breast Unit, Monash Medical Centre, Moorabin, Victoria 3165 (Australia); Department of Surgery, Monash Medical Centre, Clayton, Victoria 3168, Australia and Monash Breast Unit, Monash Medical Centre, Moorabin, Victoria 3165 (Australia); Department of Pathology, Monash Medical Centre, Clayton, Victoria 3168, Australia and Monash Breast Unit, Monash Medical Centre, Moorabin, Victoria 3165 (Australia); Monash Centre for Synchrotron Science, and School of Physics, Monash University, Clayton, Victoria 3800 (Australia)

2008-10-15

191

Tissue-specific expression of the human type II collagen gene in mice  

SciTech Connect

Type II collagen is crucial to the development of form in vertebrates as it is the major protein of cartilage. To study the factors regulating its expression the authors introduced a cosmid containing the human type II collagen gene, including 4.5 kilobases of 5' and 2.2 kilobases of 3' flanking DNA, into embryonic stem cells in vitro. The transformed cells contribute to all tissues in chimeric mice allowing the expression of the exogenous gene to be studied in vivo. Human type II collagen mRNA is restricted to tissues showing transcription from the endogenous gene and human type II collagen is found in extracellular matrix surrounding chondrocytes in cartilage. The results indicate that the cis-acting requirements for correct temporal and spatial regulation of the gene are contained with the introduced DNA.

Lovell-Badge, R.H.; Bygrave, A.; Bradley, A.; Robertson, E.; Tilly, R.; Cheah, K.S.E.

1987-05-01

192

Combined Ultrasound and MR Imaging to Guide Focused Ultrasound Therapies in the Brain  

PubMed Central

Purpose Several emerging therapies with potential for use in the brain harness effects produced by acoustic cavitation – the interaction between ultrasound and microbubbles either generated during sonication or introduced into the vasculature. Systems developed for transcranial MRI-guided focused ultrasound (MRgFUS) thermal ablation can enable their clinical translation, but methods for real-time monitoring and control are currently lacking. Acoustic emissions produced during sonication can provide information about the location, strength, and type of the microbubble oscillations within the ultrasound field, and they can be mapped in real-time using passive imaging approaches. Here, we tested whether such mapping can be achieved transcranially within a clinical brain MRgFUS system. Materials and Methods We integrated an ultrasound imaging array into the hemisphere transducer of the MRgFUS device. Passive cavitation maps were obtained during sonications combined with a circulating microbubble agent at 20 targets in the cingulate cortex in three macaques. The maps were compared with MRI-evident tissue effects. Results The system successfully mapped microbubble activity during both stable and inertial cavitation, which was correlated with MRI-evident transient blood-brain barrier disruption and vascular damage, respectively. The location of this activity was coincident with the resulting tissue changes within the expected resolution limits of the system. Conclusion While preliminary, these data clearly demonstrate, for the first time, that is possible to construct maps of stable and inertial cavitation transcranially, in a large animal model, and under clinically relevant conditions. Further, these results suggest that this hybrid ultrasound/MRI approach can provide comprehensive guidance for targeted drug delivery via blood-brain barrier disruption and other emerging ultrasound treatments, facilitating their clinical translation. We anticipate it will also prove to be an important research tool that will further the development of a broad range of microbubble-enhanced therapies. PMID:23788054

Arvanitis, Costas D.; Livingstone, Margaret S.; McDannold, Nathan

2013-01-01

193

[Tissue typing and donor-recipient selection in dogs for experimental organ transplants].  

PubMed

About first results of a tissue typing for donor recipient selection in dog is reported on obtaining an optimum degree of histocompatibility. The modified NIH-test according to Brand and coworker was carried out. The sera for typing were prepared by means of artificial or natural immunisation. Serologic and genetic problems are discussed. Possibilities on perfection are shown for donor recipient selection in dogs. PMID:7415346

Schimmack, L; Kaden, J; Groth, J; Engelmann, C

1980-01-01

194

Controlling collagen fiber microstructure in three-dimensional hydrogels using ultrasound  

PubMed Central

Type I collagen is the primary fibrillar component of the extracellular matrix, and functional properties of collagen arise from variations in fiber structure. This study investigated the ability of ultrasound to control collagen microstructure during hydrogel fabrication. Under appropriate conditions, ultrasound exposure of type I collagen during polymerization altered fiber microstructure. Scanning electron microscopy and second-harmonic generation microscopy revealed decreased collagen fiber diameters in response to ultrasound compared to sham-exposed samples. Results of mechanistic investigations were consistent with a thermal mechanism for the effects of ultrasound on collagen fiber structure. To control collagen microstructure site-specifically, a high frequency, 8.3-MHz, ultrasound beam was directed within the center of a large collagen sample producing dense networks of short, thin collagen fibrils within the central core of the gel and longer, thicker fibers outside the beam area. Fibroblasts seeded onto these gels migrated rapidly into small, circularly arranged aggregates only within the beam area, and clustered fibroblasts remodeled the central, ultrasound-exposed collagen fibrils into dense sheets. These investigations demonstrate the capability of ultrasound to spatially pattern various collagen microstructures within an engineered tissue noninvasively, thus enhancing the level of complexity of extracellular matrix microenvironments and cellular functions achievable within three-dimensional engineered tissues. PMID:23927189

Garvin, Kelley A.; VanderBurgh, Jacob; Hocking, Denise C.; Dalecki, Diane

2013-01-01

195

Improved centration of the type 1 Boston Keratoprosthesis in donor carrier tissue.  

PubMed

The type 1 Boston Keratoprosthesis preparation requires a 3-mm central punch and an 8.5 mm or larger punch in the carrier tissue. These punches are ideally concentric, but we have found difficulty in achieving concentric punches when the larger punch is performed first. We present a modification in the preparation procedure to help minimize centration error. PMID:20823936

Khalifa, Yousuf M; Moshirfar, Majid

2010-01-01

196

Improved centration of the type 1 Boston Keratoprosthesis in donor carrier tissue  

PubMed Central

The type 1 Boston Keratoprosthesis preparation requires a 3-mm central punch and an 8.5 mm or larger punch in the carrier tissue. These punches are ideally concentric, but we have found difficulty in achieving concentric punches when the larger punch is performed first. We present a modification in the preparation procedure to help minimize centration error. PMID:20823936

Khalifa, Yousuf M; Moshirfar, Majid

2010-01-01

197

Analysis of Artificial Radiocarbon in Different Skeletal and Dental Tissue Types to Evaluate Date of Death  

Microsoft Academic Search

Radiocarbon dating, with special reference to the modern bomb-curve, can provide useful information to elucidate the date of death of skeletonized human remains. Interpretation can be enhanced with analysis of different types of tissues within a single skeleton because of the known variability of formation times and remodeling rates. Analysis of radiocarbon content of teeth, especially the enamel in tooth

D H Ubelaker; B A Buchholz; J Stewart

2005-01-01

198

Molecular Imaging with Targeted Contrast Ultrasound  

Microsoft Academic Search

Molecular imaging with contrast-enhanced ultrasound uses targeted microbubbles that are retained in diseased tissue. The resonant properties of these microbubbles produce acoustic signals in an ultrasound field. The microbubbles are targeted to diseased tissue by using certain chemical constituents in the microbubble shell or by attaching disease-specific ligands such as antibodies to the microbubble. In this review, we discuss the

Mark Piedra; Achim Allroggen; Jonathan R. Lindner

2009-01-01

199

Interventional ultrasound  

SciTech Connect

This book discusses: Introduction to interventional ultrasound/handling of aspirated material/general principles of fine needle aspiration cytology/procedure and principles in ultrasonically guided puncture/puncture of focal liver lesions/intraoperative puncture of the liver guided by ultrasound/Interventional ultrasound in cancer therapy/Interventional echocardiography/Fine-needle aspiration biopsy: Are there any risks./Puncture of renal mass lesions/Intrauterine needle diagnosis/Percutaneous nephrolithotomy.

Holm, H.H.; Kristensen, J.K.

1985-01-01

200

Multiplatform analysis of 12 cancer types reveals molecular classification within and across tissues of origin.  

PubMed

Recent genomic analyses of pathologically defined tumor types identify "within-a-tissue" disease subtypes. However, the extent to which genomic signatures are shared across tissues is still unclear. We performed an integrative analysis using five genome-wide platforms and one proteomic platform on 3,527 specimens from 12 cancer types, revealing a unified classification into 11 major subtypes. Five subtypes were nearly identical to their tissue-of-origin counterparts, but several distinct cancer types were found to converge into common subtypes. Lung squamous, head and neck, and a subset of bladder cancers coalesced into one subtype typified by TP53 alterations, TP63 amplifications, and high expression of immune and proliferation pathway genes. Of note, bladder cancers split into three pan-cancer subtypes. The multiplatform classification, while correlated with tissue-of-origin, provides independent information for predicting clinical outcomes. All data sets are available for data-mining from a unified resource to support further biological discoveries and insights into novel therapeutic strategies. PMID:25109877

Hoadley, Katherine A; Yau, Christina; Wolf, Denise M; Cherniack, Andrew D; Tamborero, David; Ng, Sam; Leiserson, Max D M; Niu, Beifang; McLellan, Michael D; Uzunangelov, Vladislav; Zhang, Jiashan; Kandoth, Cyriac; Akbani, Rehan; Shen, Hui; Omberg, Larsson; Chu, Andy; Margolin, Adam A; Van't Veer, Laura J; Lopez-Bigas, Nuria; Laird, Peter W; Raphael, Benjamin J; Ding, Li; Robertson, A Gordon; Byers, Lauren A; Mills, Gordon B; Weinstein, John N; Van Waes, Carter; Chen, Zhong; Collisson, Eric A; Benz, Christopher C; Perou, Charles M; Stuart, Joshua M

2014-08-14

201

Using Data Fusion to Characterize Breast Tissue  

SciTech Connect

New ultrasound data, obtained with a circular experimental scanner, are compared with data obtained with standard X-ray CT. Ultrasound data obtained by scanning fixed breast tissue were used to generate images of sound speed and reflectivity. The ultrasound images exhibit approximately 1 mm resolution and about 20 dB of dynamic range. All data were obtained in a circular geometry. X-ray CT scans were used to generate X-ray images corresponding to the same 'slices' obtained with the ultrasound scanner. The good match of sensitivity, resolution and angular coverage between the ultrasound and X-ray data makes possible a direct comparison of the three types of images. We present the results of such a comparison for an excised breast fixed in formalin. The results are presented visually using various types of data fusion. A general correspondence between the sound speed, reflectivity and X-ray morphologies is found. The degree to which data fusion can help characterize tissue is assessed by examining the quantitative correlations between the ultrasound and X-ray images.

Littrup, P; Duric, N; Leach, R R; Azevedo, S G; Candy, J V; Moore, T; Chambers, D H; Mast, J E; Johnson, S A; Holsapple, E

2002-01-23

202

Broadband miniature fiber optic ultrasound generator.  

PubMed

This paper presents the design, fabrication and characterization of a broadband miniature fiber optic ultrasound generator based on photoacoustic (PA) ultrasound generation principle for biomedical ultrasound imaging and ultrasound non-destructive test (NDT) applications. A novel PA generation material, gold nanocomposite, was synthesized by directly reducing gold nanoparticles within polydimethylsiloxane (PDMS) through a one-pot protocol. The fiber optic ultrasound generator was fabricated by coating the gold nanocomposite on the tip of the optical fiber. The efficiency of the PA generation using gold nanocomposite was increased 10(5) compared to using aluminum thin film and 10(3) compared to using graphite mixed within epoxy. The ultrasound profile and the acoustic distribution have been characterized. The amplitude of the generated ultrasound signal was as high as 0.64 MPa and the bandwidth was more than 20 MHz. This paper also demonstrated its capability for ultrasound imaging of a tissue specimen. PMID:25089431

Zou, Xiaotian; Wu, Nan; Tian, Ye; Wang, Xingwei

2014-07-28

203

Complex heterogeneous tissue constructs containing multiple cell types prepared by inkjet printing technology.  

PubMed

This study was designed to develop a versatile method for fabricating complex and heterogeneous three-dimensional (3D) tissue constructs using simultaneous ink-jetting of multiple cell types. Human amniotic fluid-derived stem cells (hAFSCs), canine smooth muscle cells (dSMCs), and bovine aortic endothelial cells (bECs), were separately mixed with ionic cross-linker calcium chloride (CaCl(2)), loaded into separate ink cartridges and printed using a modified thermal inkjet printer. The three cell types were delivered layer-by-layer to pre-determined locations in a sodium alginate-collagen composite located in a chamber under the printer. The reaction between CaCl(2) and sodium alginate resulted in a rapid formation of a solid composite gel and the printed cells were anchored in designated areas within the gel. The printing process was repeated for several cycles leading to a complex 3D multi-cell hybrid construct. The biological functions of the 3D printed constructs were evaluated in vitro and in vivo. Each of the printed cell types maintained their viability and normal proliferation rates, phenotypic expression, and physiological functions within the heterogeneous constructs. The bioprinted constructs were able to survive and mature into functional tissues with adequate vascularization in vivo. These findings demonstrate the feasibility of fabricating complex heterogeneous tissue constructs containing multiple cell types using inkjet printing technology. PMID:23063369

Xu, Tao; Zhao, Weixin; Zhu, Jian-Ming; Albanna, Mohammad Z; Yoo, James J; Atala, Anthony

2013-01-01

204

Interventional ultrasound  

SciTech Connect

This book contains 12 chapters and several case studies. Some of the chapter titles are: The Interplay of Ultrasound and Computed Tomography in the Planning and Execution of Interventional Procedures: Ulltrasound Guided Biopsy; Interventioal Genitourinary Sonography; Diagnosis and Treatment of Pericardial Effusion Using Ultrasonic Guidance; and New Ultrasound-Guided Interventional Procedures--Cholecystostomy, Pancreatography, Gastrostomy.

VanSonnenberg, E. (Univ. of California, San Diego School of Medicine, La Jolla, CA (US))

1987-01-01

205

Genomic imprinting variations in the mouse type 3 deiodinase gene between tissues and brain regions.  

PubMed

The Dio3 gene, which encodes for the type 3 deiodinase (D3), controls thyroid hormone (TH) availability. The lack of D3 in mice results in tissue overexposure to TH and a broad neuroendocrine phenotype. Dio3 is an imprinted gene, preferentially expressed from the paternally inherited allele in the mouse fetus. However, heterozygous mice with paternal inheritance of the inactivating Dio3 mutation exhibit an attenuated phenotype when compared with that of Dio3 null mice. To investigate this milder phenotype, the allelic expression of Dio3 was evaluated in different mouse tissues. Preferential allelic expression of Dio3 from the paternal allele was observed in fetal tissues and neonatal brain regions, whereas the biallelic Dio3 expression occurred in the developing eye, testes, and cerebellum and in the postnatal brain neocortex, which expresses a larger Dio3 mRNA transcript. The newborn hypothalamus manifests the highest degree of Dio3 expression from the paternal allele, compared with other brain regions, and preferential allelic expression of Dio3 in the brain relaxed in late neonatal life. A methylation analysis of two regulatory regions of the Dio3 imprinted domain revealed modest but significant differences between tissues, but these did not consistently correlate with the observed patterns of Dio3 allelic expression. Deletion of the Dio3 gene and promoter did not result in significant changes in the tissue-specific patterns of Dio3 allelic expression. These results suggest the existence of unidentified epigenetic determinants of tissue-specific Dio3 imprinting. The resulting variation in the Dio3 allelic expression between tissues likely explains the phenotypic variation that results from paternal Dio3 haploinsufficiency. PMID:25232934

Martinez, M Elena; Charalambous, Marika; Saferali, Aabida; Fiering, Steven; Naumova, Anna K; St Germain, Donald; Ferguson-Smith, Anne C; Hernandez, Arturo

2014-11-01

206

Contourlet Transform for Texture Representation of Ultrasound Thyroid Images  

E-print Network

Contourlet Transform for Texture Representation of Ultrasound Thyroid Images Stamos Katsigiannis analysis. This paper investigates the texture representation of thyroid tissue via features based ultrasound thyroid textures have been utilized. The maximum classification accuracy was 93%, showing that CT

Athens, University of

207

SNPsea: an algorithm to identify cell types, tissues and pathways affected by risk loci  

PubMed Central

Summary: We created a fast, robust and general C++ implementation of a single-nucleotide polymorphism (SNP) set enrichment algorithm to identify cell types, tissues and pathways affected by risk loci. It tests trait-associated genomic loci for enrichment of specificity to conditions (cell types, tissues and pathways). We use a non-parametric statistical approach to compute empirical P-values by comparison with null SNP sets. As a proof of concept, we present novel applications of our method to four sets of genome-wide significant SNPs associated with red blood cell count, multiple sclerosis, celiac disease and HDL cholesterol. Availability and implementation: http://broadinstitute.org/mpg/snpsea Contact: soumya@broadinstitute.org Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24813542

Slowikowski, Kamil; Hu, Xinli; Raychaudhuri, Soumya

2014-01-01

208

Validation of four-dimensional ultrasound for targeting in minimally-invasive beating-heart surgery  

NASA Astrophysics Data System (ADS)

Ultrasound is garnering significant interest as an imaging modality for surgical guidance, due to its affordability, real-time temporal resolution and ease of integration into the operating room. Minimally-invasive intracardiac surgery performed on the beating-heart prevents direct vision of the surgical target, and procedures such as mitral valve replacement and atrial septal defect closure would benefit from intraoperative ultrasound imaging. We propose that placing 4D ultrasound within an augmented reality environment, along with a patient-specific cardiac model and virtual representations of tracked surgical tools, will create a visually intuitive platform with sufficient image information to safely and accurately repair tissue within the beating heart. However, the quality of the imaging parameters, spatial calibration, temporal calibration and ECG-gating must be well characterized before any 4D ultrasound system can be used clinically to guide the treatment of moving structures. In this paper, we describe a comprehensive accuracy assessment framework that can be used to evaluate the performance of 4D ultrasound systems while imaging moving targets. We image a dynamic phantom that is comprised of a simple robot and a tracked phantom to which point-source, distance and spherical objects of known construction can be attached. We also follow our protocol to evaluate 4D ultrasound images generated in real-time by reconstructing ECG-gated 2D ultrasound images acquired from a tracked multiplanar transesophageal probe. Likewise, our evaluation framework allows any type of 4D ultrasound to be quantitatively assessed.

Pace, Danielle F.; Wiles, Andrew D.; Moore, John; Wedlake, Chris; Gobbi, David G.; Peters, Terry M.

2009-02-01

209

Ultrasound-enhanced delivery of targeted echogenic liposomes in a novel ex vivo mouse aorta model  

PubMed Central

The goal of this study was to determine whether targeted, Rhodamine-labeled echogenic liposomes (Rh-ELIP) containing nanobubbles could be delivered to the arterial wall, and whether 1 MHz continuous wave ultrasound would enhance this delivery profile. Aortae excised from apolipoprotein-E-deficient (n = 8) and wild-type (n = 8) mice were mounted in a pulsatile flow system through which Rh-ELIP were delivered in a stream of bovine serum albumin. Half the aortae from each group were treated with 1-MHz continuous wave ultrasound at 0.49 MPa peak-to-peak pressure, and half underwent sham exposure. Ultrasound parameters were chosen to promote stable cavitation and avoid inertial cavitation. A broadband hydrophone was used to monitor cavitation activity. After treatment, aortic sections were prepared for histology and analyzed by an individual blinded to treatment conditions. Delivery of Rh-ELIP to the vascular endothelium was observed, and subendothelial penetration of Rh-ELIP was present in five of five ultrasound-treated aortae and was absent in those not exposed to ultrasound. However, the degree of penetration in the ultrasound-exposed aortae was variable. There was no evidence of ultrasound-mediated tissue damage in any specimen. Ultrasound-enhanced delivery within the arterial wall was demonstrated in this novel model, which allows quantitative evaluation of therapeutic delivery. PMID:20202474

Hitchcock, Kathryn E.; Caudell, Danielle N.; Sutton, Jonathan T.; Klegerman, Melvin E.; Vela, Deborah; Pyne-Geithman, Gail J.; Abruzzo, Todd; Cyr, Peppar E. P.; Geng, Yong-Jian; McPherson, David D.; Holland, Christy K.

2010-01-01

210

Urokinase-type plasminogen activator receptor in gastric cancer: tissue expression and prognostic role  

Microsoft Academic Search

The urokinase-type plasminogen activator (UPA) and its inhibitor PAI-1 are thought to play an important part in gastric cancer (GC) invasion and metastasis. Little is known about the behavior and prognostic impact of the receptor for UPA (UPAR). The aims of the present study were: (1) to measure UPAR, UPA and PAI-1 levels in GC and in non-malignant tissue distant

Mario Plebani; Làszlo Herszènyi; Paolo Carraro; Massimo De Paoli; Giovanni Roveroni; Romilda Cardin; Zsolt Tulassay; Remo Naccarato; Fabio Farinati

1997-01-01

211

A- and B-type lamins are differentially expressed in normal human tissues  

Microsoft Academic Search

A selection of normal human tissues was investigated for the presence of lamins B1, B2, and A-type lamins, using a panel\\u000a of antibodies specific for the individual lamin subtypes. By use of immunoprecipitation and two-dimensional immunoblotting\\u000a techniques we demonstrated that these antibodies do not cross-react with other lamin subtypes and that a range of different\\u000a phosphorylation isoforms is recognized by

Jos L. V. Broers; Barbie M. Machiels; Helma J. H. Kuijpers; Frank Smedts; Ronald van den Kieboom; Yves Raymond; Frans C. S. Ramaekers

1997-01-01

212

Increased Plasma Tissue-Type Plasminogen Activator Levels in Patients with Chronic Thrombocytopenia  

Microsoft Academic Search

Plasma fibrinolytic factors were measured in 14 patients with chronic idiopathic thrombocytopenic purpura (ITP), in 5 patients with chronic central thrombocytopenia and in 16 healthy volunteers. The von Willebrand factor (vWF), tissue-type plasminogen activator (t-PA) and D-dimer (DD) antigens were found to be significantly higher in both patient groups than in the control group. No difference appeared in euglobulin fibrinolytic

M. Hanss; D. Ville; M. Dechavanne

1990-01-01

213

New tetrachromic VOF stain (Type III-G.S) for normal and pathological fish tissues.  

PubMed

A new VOF Type III-G.S stain was applied to histological sections of different organs and tissues of healthy and pathological larvae, juvenile and adult fish species (Solea senegalensis; Sparus aurata; Diplodus sargo; Pagrus auriga; Argyrosomus regius and Halobatrachus didactylus). In comparison to the original Gutiérrez VOF stain, more acid dyes of contrasting colours and polychromatic/metachromatic properties were incorporated as essential constituents of the tetrachromic VOF stain. This facilitates the selective staining of different basic tissues and improves the morphological analysis of histochemical approaches of the cell components. The VOF Type III -6.5 stain is composed of a mixture of several dyes of varying size and molecular weight (Orange Gtissues to be selectively differentiated and stained. Muscle fibers, collagen, reticulin and elastin fibers, erythrocytes, cartilage, bone, mucous cells, oocytes and larvae were selectively stained and differentiated. Dyes with small size and molecular weight (i.e Orange G), penetrate all tissue structures rapidly, but are only tightly retained in densely textured tissues (i.e erythrocytes). Methyl Blue is an interesting triarylmethane dye (large size and molecular weight), which is incorporated in this new VOF tetrachrome stain, and acquires histochemical significance when used at acid pH (2.8) because collagen and reticulin fibers, as well basophilic and metachromatic substances (strongly ionized sulphated glycoconjugates) can be identified. Muscle tissues show an evident green colour (Fast Green or Light Green affinities), even those isolated and/or diffuse muscle fibers present in the digestive submucosa layer. Connective tissues showed a specific and strong blue colour (Methyl Blue affinity) or mixed blue-red staining (Methyl Blue and Acid Fucshin affinities). Very noticeable is the staining of the mucous cells, as well as the hyaline capsule of the viral lymphocystic cells, which were stained blue-purple (carboxylated and/or strongly ionized sulphated groups). Cartilaginous tissues showed a blue or purple (Methyl Blue affinity) staining, and a specific red colour (Acid Fucshin affinity) was evident during calcification or in bone structures (i.e skeleton, fins, gills, teeth). PMID:15967749

Sarasquete, C; Gutiérrez, M

2005-01-01

214

Assessment of three types of spaceflight hardware for tissue culture studies: Comparison of skeletal tissue growth and differentiation  

SciTech Connect

Three different types of spaceflight hardware, the BioProcessing Module (BPM), the Materials Dispersion Apparatus (MDA), and the Fluid Processing Apparatus (FPA), were assessed for their ability to support pre-metatarsal growth and differentiation in experiments conducted on five space shuttle flights. BPM-cultured pre-metatarsal tissue showed no difference in flight and ground control lengths. Flight and ground controls cultured in the MDA grew 135 {mu}m and 141 {mu}m, respectively, in an 11 day experiment. Only five control rods and three flight rods mineralized. In another MDA experiment, pre-metatarsals were cultured at 4{degree}C (277K) or 20{degree}C (293K) for the 16 day mission, then cultured an additional 16 days in laboratory dishes at 37{degree}C (310K). The 20{degree}C (293K) cultures died post-flight. The 4{degree}C (277K) flight pre-metatarsals grew 417 {mu}m more than the 4{degree}C (277K) ground controls post-flight. In 5 and 6 day experiments done in FPAs, flight rods grew longer than ground control rods. In a 14 day experiment, ground control and flight rods also expanded in length, but there was no difference between them. The pre-metatarsals cultured in the FPAs did not mineralize, or terminally differentiate. These experiments demonstrate, that while supporting pre-metatarsal growth in length, the three types of hardware are not suitable to support routine differentiation. {copyright} {ital 1997 American Institute of Physics.}

Klement, B.J. [Space Medicine and Life Sciences Research Center Department of Anatomy Morehouse School of Medicine 720 Westview Dr. SW Atlanta, Georgia30310-1495 (United States); Spooner, B.S. [NASA Specialized Center of Research and Training Division of Biology Ackert Hall Kansas State University Manhattan, Kansas66506 (United States)

1997-01-01

215

A cytogenetic analysis of 2 cases of phosphaturic mesenchymal tumor of mixed connective tissue type.  

PubMed

Phosphaturic mesenchymal tumor of mixed connective tissue type is a rare, histologically distinctive mesenchymal neoplasm associated with tumor-induced osteomalacia resulting from production of the phosphaturic hormone fibroblast growth factor 23. Because of its rarity, specific genetic alterations that contribute to the pathogenesis of these tumors have yet to be elucidated. Herein, we report the abnormal karyotypes from 2 cases of confirmed phosphaturic mesenchymal tumor of mixed connective tissue type. G-banded analysis demonstrated the first tumor to have a karyotype of 46,Y,t(X;3;14)(q13;p25;q21)[15]/46XY[5], and the second tumor to have a karyotype of 46, XY,add(2)(q31),add(4)(q31.1)[2]/92,slx2[3]/46,sl,der(2)t(2;4)(q14.2;p14),der(4)t(2;4)(q14.2;p14),add(4)(q31.1)[10]/46,sdl,add(13)(q34)[4]/92,sdl2x2[1]. These represent what is, to our knowledge, the first examples of abnormal karyotypes obtained from phosphaturic mesenchymal tumor of mixed connective tissue type. PMID:22503486

Graham, Rondell P; Hodge, Jennelle C; Folpe, Andrew L; Oliveira, Andre M; Meyer, Kevin J; Jenkins, Robert B; Sim, Franklin H; Sukov, William R

2012-08-01

216

Tissue-Specific Remodeling of the Mitochondrial Proteome in Type 1 Diabetic Akita Mice  

PubMed Central

OBJECTIVE To elucidate the molecular basis for mitochondrial dysfunction, which has been implicated in the pathogenesis of diabetes complications. RESEARCH DESIGN AND METHODS Mitochondrial matrix and membrane fractions were generated from liver, brain, heart, and kidney of wild-type and type 1 diabetic Akita mice. Comparative proteomics was performed using label-free proteome expression analysis. Mitochondrial state 3 respirations and ATP synthesis were measured, and mitochondrial morphology was evaluated by electron microscopy. Expression of genes that regulate mitochondrial biogenesis, substrate utilization, and oxidative phosphorylation (OXPHOS) were determined. RESULTS In diabetic mice, fatty acid oxidation (FAO) proteins were less abundant in liver mitochondria, whereas FAO protein content was induced in mitochondria from all other tissues. Kidney mitochondria showed coordinate induction of tricarboxylic acid (TCA) cycle enzymes, whereas TCA cycle proteins were repressed in cardiac mitochondria. Levels of OXPHOS subunits were coordinately increased in liver mitochondria, whereas mitochondria of other tissues were unaffected. Mitochondrial respiration, ATP synthesis, and morphology were unaffected in liver and kidney mitochondria. In contrast, state 3 respirations, ATP synthesis, and mitochondrial cristae density were decreased in cardiac mitochondria and were accompanied by coordinate repression of OXPHOS and peroxisome proliferator–activated receptor (PPAR)-? coactivator (PGC)-1? transcripts. CONCLUSIONS Type 1 diabetes causes tissue-specific remodeling of the mitochondrial proteome. Preservation of mitochondrial function in kidney, brain, and liver, versus mitochondrial dysfunction in the heart, supports a central role for mitochondrial dysfunction in diabetic cardiomyopathy. PMID:19542201

Bugger, Heiko; Chen, Dong; Riehle, Christian; Soto, Jamie; Theobald, Heather A.; Hu, Xiao X.; Ganesan, Balasubramanian; Weimer, Bart C.; Abel, E. Dale

2009-01-01

217

Dysmorphic choroid plexuses and hydrocephalus associated with increased nuchal translucency: Early ultrasound markers of de novo thanatophoric dysplasia type II with cloverleaf skull (Kleeblattschaedel).  

PubMed

Prenatal diagnosis of thanatophoric dysplasia (TD) type II presenting in the first trimester with increased nuchal translucency (NT) and cloverleaf skull (Kleeblattschaedel) have been scantly reported in the medical record. Abnormal choroid plexus has been seen in association with fetal anomalies. Here we described a case of increased NT associated with indented choroid plexuses, early onset hydrocephalus and cloverleaf skull in a fetus subsequently diagnosed at early second trimester to carry a de novo mutation encoding for TD type II. The findings of dysmorphic choroid plexus, early onset hydrocephalus and cloverleaf skull at first trimester scan may be early, useful ultrasound markers of TD type II. Molecular analysis to control for possible overlapping syndromes were performed and resulted negative. Postmortem X-ray and 3D-CT scan confirmed the cloverleaf skull, narrow thorax, straight femur with rhizomelic shortening of the limbs and the presence of a communicating hydrocephalus. PMID:24517215

Tonni, Gabriele; Palmisano, Marcella; Ginocchi, Vladimiro; Ventura, Alessandro; Baldi, Maurizia; Baffico, Ave Maria

2014-11-01

218

Macrophage-inducible C-type lectin underlies obesity-induced adipose tissue fibrosis.  

PubMed

In obesity, a paracrine loop between adipocytes and macrophages augments chronic inflammation of adipose tissue, thereby inducing systemic insulin resistance and ectopic lipid accumulation. Obese adipose tissue contains a unique histological structure termed crown-like structure (CLS), where adipocyte-macrophage crosstalk is known to occur in close proximity. Here we show that Macrophage-inducible C-type lectin (Mincle), a pathogen sensor for Mycobacterium tuberculosis, is localized to macrophages in CLS, the number of which correlates with the extent of interstitial fibrosis. Mincle induces obesity-induced adipose tissue fibrosis, thereby leading to steatosis and insulin resistance in liver. We further show that Mincle in macrophages is crucial for CLS formation, expression of fibrosis-related genes and myofibroblast activation. This study indicates that Mincle, when activated by an endogenous ligand released from dying adipocytes, is involved in adipose tissue remodelling, thereby suggesting that sustained interactions between adipocytes and macrophages within CLS could be a therapeutic target for obesity-induced ectopic lipid accumulation. PMID:25236782

Tanaka, Miyako; Ikeda, Kenji; Suganami, Takayoshi; Komiya, Chikara; Ochi, Kozue; Shirakawa, Ibuki; Hamaguchi, Miho; Nishimura, Satoshi; Manabe, Ichiro; Matsuda, Takahisa; Kimura, Kumi; Inoue, Hiroshi; Inagaki, Yutaka; Aoe, Seiichiro; Yamasaki, Sho; Ogawa, Yoshihiro

2014-01-01

219

Characterization of Human Papillomavirus Type 154 and Tissue Tropism of Gammapapillomaviruses  

PubMed Central

The novel human papillomavirus type 154 (HPV154) was characterized from a wart on the crena ani of a three-year-old boy. It was previously designated as the putative HPV type FADI3 by sequencing of a subgenomic FAP amplicon. We obtained the complete genome by combined methods including rolling circle amplification (RCA), genome walking through an adapted method for detection of integrated papillomavirus sequences by ligation-mediated PCR (DIPS-PCR), long-range PCR, and finally by cloning of four overlapping amplicons. Phylogenetically, the HPV154 genome clustered together with members of the proposed species Gammapapillomavirus 11, and demonstrated the highest identity in L1 to HPV136 (68.6%). The HPV154 was detected in 3% (2/62) of forehead skin swabs from healthy children. In addition, the different detection sites of 62 gammapapillomaviruses were summarized in order to analyze their tissue tropism. Several of these HPV types have been detected from multiple sources such as skin, oral, nasal, and genital sites, suggesting that the gammapapillomaviruses are generalists with a broader tissue tropism than previously appreciated. The study expands current knowledge concerning genetic diversity and tropism among HPV types in the rapidly growing gammapapillomavirus genus. PMID:24551244

Ure, Agustin Enrique; Forslund, Ola

2014-01-01

220

Presence of six different lesion types suggests diverse mechanisms of tissue injury in neuromyelitis optica.  

PubMed

Neuromyelitis optica (NMO) is an autoimmune disease targeting aquaporin 4 (AQP4), localized mainly at the astrocytic foot processes. Loss of AQP4 and glial fibrillary acidic protein (GFAP) was reported, but the pathological significance of astrocytopathy is still controversial. Here we show that active lesions in NMO display a wide spectrum of pathology even within a single tissue block of an individual patient. We have distinguished six different lesion types. The first reflects complement deposition at the surface of astrocytes, associated with granulocyte infiltration and astrocyte necrosis and followed by demyelination, global tissue destruction and the formation of cystic, necrotic lesions (lesion type 2). Such destructive lesions lead to Wallerian degeneration in lesion-related tracts (lesion type 3). Around active NMO lesions AQP4 may selectively be lost in the absence of aquaporin 1 (AQP1) loss or other structural damage (lesion type 4). Another pattern is characterized by clasmatodendrosis of astrocytes, defined by cytoplasmic swelling and vacuolation, beading and dissolution of their processes and nuclear alterations resembling apoptosis, which was associated with internalization of AQP4 and AQP1 and astrocyte apoptosis in the absence of complement activation. Such lesions give rise to extensive astrocyte loss, which may occur in part in the absence of any other tissue injury, such as demyelination or axonal degeneration (lesion type 5). Finally, lesions with a variable degree of astrocyte clasmatodendrosis are found, which show plaque-like primary demyelination that is associated with oligodendrocyte apoptosis, but with preservation of axons (lesion type 6). In active multiple sclerosis (MS) lesions astrocytes reveal changes of reactive protoplasmatic or fibrillary gliosis. Only in a subset of lesions, in patients with aggressive disease, loss of AQP4 is observed in the initial stage of their formation, which is associated with retraction of astrocyte processes in the absence of complement deposition, granulocyte infiltration or loss of AQP1 or astrocytes. Our data underline the primary assault of astrocytes in NMO lesions, but also indicate that different mechanisms of tissue injury operate in parallel in the same patient and even within the same lesion. PMID:23579868

Misu, Tatsuro; Höftberger, Romana; Fujihara, Kazuo; Wimmer, Isabella; Takai, Yoshiki; Nishiyama, Shuhei; Nakashima, Ichiro; Konno, Hidehiko; Bradl, Monika; Garzuly, Ferenc; Itoyama, Yasuto; Aoki, Masashi; Lassmann, Hans

2013-06-01

221

Diagnosis of phosphaturic mesenchymal tumor (mixed connective tissue type) by cytopathology.  

PubMed

Oncogenic osteomalacia (OO) is a rare paraneoplastic condition in which a bone or soft tissue tumor induces biochemical and clinical signs and symptoms of osteomalacia (or rickets) most often by the production of the phosphaturic protein, fibroblast growth factor-23. Phosphaturic mesenchymal tumor, mixed connective tissue type (PMTMCT) is a rare, histologically distinct tumor that represents the most common cause of OO. As the clinical diagnosis of OO is typically suspected on the basis of clinical and biochemical features and the presence of a bone or soft tissue tumor, cytologic examination might potentially provide the necessary pathologic confirmation of OO. In this case of a 46-year-old female with clinical stigmata of OO and a right distal humeral mass, we report that the fine-needle aspiration findings of short, cytologically bland spindled cells embedded in a fine, fibrillary stromal-rich matrix and the presence of osteoclast-type giant cells associated with the stromal matrix provide strong pathological evidence for PMTMCT and assist in pathologically confirming the clinical impression of OO, thus alleviating the need for a more invasive diagnostic surgical procedure. PMID:22927293

William, Josette; Laskin, William; Nayar, Ritu; De Frias, Denise

2012-08-01

222

Benign breast lesions: Ultrasound  

PubMed Central

Benign breast diseases constitute a heterogeneous group of lesions arising in the mammary epithelium or in other mammary tissues, and they may also be linked to vascular, inflammatory or traumatic pathologies. Most lesions found in women consulting a physician are benign. Ultrasound (US) diagnostic criteria indicating a benign lesion are described as well as US findings in the most frequent benign breast lesions. PMID:23396888

Masciadri, N.; Ferranti, C.

2011-01-01

223

Musculoskeletal Ultrasound  

MedlinePLUS

... For other ultrasound exams, the patient is positioned lying face-up or face-down on an examination ... infants and children are performed with the child lying on his or her back on the examination ...

224

Transvaginal ultrasound  

MedlinePLUS

... ovary, ultrasound imaging of pelvic structures. In: Lentz GM, Lobo RA, Gershenson DM, Katz VL, eds. Comprehensive ... cell neoplasms, sex-cord stromal tumors. In: Lentz GM, Lobo RA, Gershenson DM, Katz VL, eds. Comprehensive ...

225

Ultrasound -- Pelvis  

MedlinePLUS Videos and Cool Tools

... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

226

Using real-time ultrasound and carcass measurements to estimate total internal fat in beef cattle over different breed types and managements.  

PubMed

The objective of this study was to re-evaluate our previously published technique of estimating total physically separable internal fat (IFAT) in beef cattle using real-time ultrasound (RTU) and carcass measurements from live animals by including more breed types and genders under different management scenarios. We expanded the original database and performed additional analyses. The database was gathered from 4 studies and contained 110 animals (16 bulls, 16 heifers, and 78 steers), being Angus (n = 56), Angus× 5/8 Angus × 3/8 Nellore (n = 18), and Angus crossbreds (n = 36). Ultrasound measurements were obtained 7 d before slaughter, including the 12th to 13th rib fat thickness (uBF) and ultrasound kidney fat depth (uKFd). The uKFd was measured in a cross-sectional image collected between the first lumbar and 13th rib as previously published. Carcass data were collected 48 h post-mortem and consisted of backfat thickness (cBF), kidney fat depth (cKFd) and KPH weight, live BW, and HCW. Whole gastrointestinal tracts were removed and dissected to obtain IFAT weights. Weight of IFAT was highly correlated with KPH weight (0.88) and cKFd (0.81) and moderately correlated with uKFd (0.71). Prediction equations were developed for estimating IFAT, KPH weight, and cKFd with the PROC REG of SAS using the stepwise statement. The best predictors of IFAT were KPH weight or cKFd and cBF (r(2) = 0.84 and 0.83 and root mean square errors (RMSE) of 4.23 and 4.33 kg, respectively). Ultrasound measurements of uKFd and uBF had an r(2) of 0.65 and RMSE of 6.07 kg when both were used to predict IFAT. The results of cross-validation analyses indicated that equations developed either with KPH weight or cKFd weight and cBF had greater precision than the equation developed with uKFd and uBF. Most of the errors associated with the mean square error of prediction were due to random, uncontrolled variation. These results were consistent with previously published evaluation of this technique. These findings confirm that this RTU technique allows the measurement of IFAT in a non-invasive way that may improve our ability to estimate IFAT in beef cattle, be used to more accurately formulate rations, and be applied in sorting cattle at feedyard. PMID:22585821

Ribeiro, F R B; Tedeschi, L O

2012-09-01

227

Tissue Identification in Ultrasound Images using Rayleigh Local Parameter Santiago Aja-Fernaindez, Marcos Martin-Fernaindez and Carlos Alberola-L6pez*  

E-print Network

imaging systems, such as syn- thetic aperture radar (SAR), laser illuminated or ultrasound images will be able to model the envelope as a Rayleigh distribution [3]. This distribution is parametrized by a. Different statistical models have been proposed to deal with such a noise, based mainly on different assump

228

Programmed Cell Death and the Pathogenesis of Tissue Injury Induced by Type A Francisella tularensis  

PubMed Central

Francisella tularensis is a highly virulent bacterial species that causes various forms of tularemia in human beings. The urgency in understanding the pathogenesis of these diseases has stimulated unprecedented interest in this bacterial species over the past few years. Recent findings underscore a number of important distinctions between the Francisella subspecies and emphasize the importance of using type A F. tularensis strains when characterizing pathophysiological responses that are relevant to the lethal forms of human disease. This review focuses on the mediators of cell death induction in infected tissues and the implications of these processes to the pathophysiological changes observed in various host species. PMID:19811540

Parmely, Michael J.; Fischer, Jeffrey L.; Pinson, David M.

2009-01-01

229

Up-regulation of tissue-type transglutaminase after traumatic brain injury  

Microsoft Academic Search

Tissue-type transglutaminase (tTG, EC 2.3.2.13) has been implicated in various disease paradigms including neurode- generative disease. In these studies, tTG induction after traumatic brain injury was studied using a rat cortical impact model. Using western blots, two forms of tTG protein expression were identified - a79-kDa primary form (tTG-L) and a less abundant70-kDa form (tTG-S). Both forms of tTG protein

Paul J. Tolentino; S. Michelle DeFord; Lucia Notterpek; Christopher C. Glenn; Brian R. Pike; Kevin K. W. Wang; Ronald L. Hayes

2002-01-01

230

Soft tissue sarcomas and central nervous system tumors in children with neurofibromatosis type 1  

Microsoft Academic Search

Objects  We aim to evaluate the characteristics of pediatric patients with neurofibromatosis type 1 (NF1) who developed soft tissue\\u000a sarcomas (STSs) and central nervous system (CNS) tumors that have been followed up in our center.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and methods  Medical records of children with NF1 were retrospectively analyzed.\\u000a \\u000a \\u000a \\u000a Results  There were 78 patients who met at least two diagnostic criteria for NF1. The median

Emre Cecen; Dilek Ince; Kamer Mutafoglu Uysal; Erdener Ozer; Riza Cetingoz; Ali Aykan Ozguven; Handan Cakmakci; Faik Sarialioglu; Nur Olgun

231

Presence of antibodies specific to cartilage-type collagen in rheumatoid synovial tissue.  

PubMed Central

Synovial membranes of rheumatoid arthritis patients were examined by fluorescence microscopy for the presence of cells producing different classes of immunoglobulins and for the incidence of antibodies to human collagens. IgG and IgM immunoglobulins were detected while IgA, IgD and IgE were absent. When consecutive tissue sections were incubated with tetramethylrhodamine isothiocyanate-labelled collagen preparations, prominent cellular and extra-cellular staining was observed only with cartilage-derived Type II collagen. Images Fig. 1 PMID:1225486

Mestecky, J; Miller, E J

1975-01-01

232

Cell lines of novel type derived from a diabetic secrete tissue-reactive human monoclonal antibodies.  

PubMed

Human monoclonal antibodies have been produced from lymphocytes of an acute-onset insulin-dependent diabetic patient. Peripheral blood lymphocytes were hybridized with a fusion partner HMY-1320. Initial screening of human immunoglobulin secretion was made by a nitrocellulose dot blot assay. Ten stable cell lines of novel type, secreting human immunoglobulin, were obtained. These cell lines have been maintained in continuous culture over 6 months and cryopreserved in liquid nitrogen for 14 months. Human monoclonal antibodies of IgG and IgM class have been produced and are secreted at a rate of 150-650 ng/ml/10(6) cells/day. Monoclonal antibodies were tested for histological staining against a variety of endocrine and non-endocrine tissues. One monoclonal antibody, LT1E12, demonstrates a staining pattern in human, rat, and mouse tissues, similar to that of mitochondrial antibodies. Another antibody, LT3C4, demonstrates weak staining of smooth muscle in rat and mouse kidney sections. Neither specificities were detected in the diabetic patient's serum. The variety of immune tissue specificities obtained in this study demonstrates the potential value of human monoclonal antibodies as probes to analyze the complexity of autoimmunity in diabetes mellitus. PMID:1873494

De Silva, M G; Ebsworth, N M; Dodwell, L C; Moyle, S P; Swana, G T; Tan, K S

1991-01-01

233

Porosity, Mineralization, Tissue Type and Morphology Interactions at the Human Tibial Cortex  

NASA Astrophysics Data System (ADS)

Prior research has shown a relationship between tibia robustness (ratio of cross-sectional area to bone length) and stress fracture risk, with less robust bones having a higher risk, which may indicate a compensatory increase in elastic modulus to increase bending strength. Previous studies of human tibiae have shown higher ash content in slender bones. In this study, the relationships between variations in volumetric porosity, ash content, tissue mineral density, secondary bone tissue, and cross sectional geometry, were investigated in order to better understand the tissue level adaptations that may occur in the establishment of cross-sectional properties. In this research, significant differences were found between porosity, ash content, and tissue type around the cortex between robust and slender bones, suggesting that there was a level of co-adaption occurring. Variation in porosity correlated with robustness, and explained large parts of the variation in tissue mineral density. The nonlinear relationship between porosity and ash content may support that slender bones compensate for poor geometry by increasing ash content through reduced remodeling, while robust individuals increase porosity to decrease mass, but only to a point. These results suggest that tissue level organization plays a compensatory role in the establishment of adult bone mass, and may contribute to differences in bone aging between different bone phenotypes. The results suggest that slender individuals have significantly less remodeled bone, however the proportion of remodeled bone was not uniform around the tibia. In the complex results of the study of 38% vs. 66% sites the distal site was subject to higher strains than the 66% site, indicating both local and global regulators may be affecting overall remodeling rates and need to be teased apart in future studies. This research has broad clinical implications on the diagnosis and treatment of fragility fractures. The relationships that were found between local variables and global geometry indicate that there was a fundamental difference between robust and slender bones, which affect the overall properties of the bone. This could allow for simple testing of bone geometry to predict an individual's fracture risk.

Hampson, Naomi A.

234

The Hedgehog (Hh) family of signaling molecules are key agents in patterning numerous types of tissues. Mutations in Hh  

E-print Network

of secreted signaling molecules as key organizers of tissue patterning. Initially discovered in Drosophila, Hh503 The Hedgehog (Hh) family of signaling molecules are key agents in patterning numerous types of tissues. Mutations in Hh and its downstream signaling molecules are also associated with numerous

Perrimon, Norbert

235

Non-negative blind source separation techniques for brain tumor tissue typing using in vivo MRSI data  

E-print Network

Non-negative blind source separation techniques for brain tumor tissue typing using in vivo MRSI in differentiating and grading glial brain tumors is limited by the significant variability of in vivo spectra due

236

21 CFR 1271.85 - What donor testing is required for different types of cells and tissues?  

Code of Federal Regulations, 2012 CFR

...2) Human immunodeficiency virus, type 2; (3) Hepatitis B virus; (4) Hepatitis C virus; and (5) Treponema pallidum . (b) Donors of viable, leukocyte-rich cells or tissue . In addition to the relevant communicable...

2012-04-01

237

21 CFR 1271.85 - What donor testing is required for different types of cells and tissues?  

...2) Human immunodeficiency virus, type 2; (3) Hepatitis B virus; (4) Hepatitis C virus; and (5) Treponema pallidum. (b) Donors of viable, leukocyte-rich cells or tissue. In addition to the relevant communicable...

2014-04-01

238

21 CFR 1271.85 - What donor testing is required for different types of cells and tissues?  

Code of Federal Regulations, 2013 CFR

...2) Human immunodeficiency virus, type 2; (3) Hepatitis B virus; (4) Hepatitis C virus; and (5) Treponema pallidum . (b) Donors of viable, leukocyte-rich cells or tissue . In addition to the relevant communicable...

2013-04-01

239

Amplification of Herpes simplex type 1 and Human Herpes type 5 viral DNA from formalin-fixed Alzheimer brain tissue  

Microsoft Academic Search

It is known that nucleic acids from formalin-fixed tissues are not nearly as good templates for DNA amplification as those extracted from fresh tissues. However, specimens stored in most pathologic archives are initially fixed in formalin. The possibility of an infectious etiology of several diseases including Alzheimer's underscores the usefulness of archived tissue in assessing the association of infectious agents

John D. Rodriguez; Donald Royall; Luke T. Daum; Kathleen Kagan-Hallet; James P. Chambers

2005-01-01

240

Propolis Modifies Collagen Types I and III Accumulation in the Matrix of Burnt Tissue  

PubMed Central

Wound healing represents an interactive process which requires highly organized activity of various cells, synthesizing cytokines, growth factors, and collagen. Collagen types I and III, serving as structural and regulatory molecules, play pivotal roles during wound healing. The aim of this study was to compare the propolis and silver sulfadiazine therapeutic efficacy throughout the quantitative and qualitative assessment of collagen types I and III accumulation in the matrix of burnt tissues. Burn wounds were inflicted on pigs, chosen for the evaluation of wound repair because of many similarities between pig and human skin. Isolated collagen types I and III were estimated by the surface plasmon resonance method with a subsequent collagenous quantification using electrophoretic and densitometric analyses. Propolis burn treatment led to enhanced collagens and its components expression, especially during the initial stage of the study. Less expressed changes were observed after silver sulfadiazine (AgSD) application. AgSD and, with a smaller intensity, propolis stimulated accumulation of collagenous degradation products. The assessed propolis therapeutic efficacy, throughout quantitatively and qualitatively analyses of collagen types I and III expression and degradation in wounds matrix, may indicate that apitherapeutic agent can generate favorable biochemical environment supporting reepithelization. PMID:23781260

Olczyk, Pawel; Wisowski, Grzegorz; Komosinska-Vassev, Katarzyna; Stojko, Jerzy; Klimek, Katarzyna; Olczyk, Monika; Kozma, Ewa M.

2013-01-01

241

Propolis Modifies Collagen Types I and III Accumulation in the Matrix of Burnt Tissue.  

PubMed

Wound healing represents an interactive process which requires highly organized activity of various cells, synthesizing cytokines, growth factors, and collagen. Collagen types I and III, serving as structural and regulatory molecules, play pivotal roles during wound healing. The aim of this study was to compare the propolis and silver sulfadiazine therapeutic efficacy throughout the quantitative and qualitative assessment of collagen types I and III accumulation in the matrix of burnt tissues. Burn wounds were inflicted on pigs, chosen for the evaluation of wound repair because of many similarities between pig and human skin. Isolated collagen types I and III were estimated by the surface plasmon resonance method with a subsequent collagenous quantification using electrophoretic and densitometric analyses. Propolis burn treatment led to enhanced collagens and its components expression, especially during the initial stage of the study. Less expressed changes were observed after silver sulfadiazine (AgSD) application. AgSD and, with a smaller intensity, propolis stimulated accumulation of collagenous degradation products. The assessed propolis therapeutic efficacy, throughout quantitatively and qualitatively analyses of collagen types I and III expression and degradation in wounds matrix, may indicate that apitherapeutic agent can generate favorable biochemical environment supporting reepithelization. PMID:23781260

Olczyk, Pawel; Wisowski, Grzegorz; Komosinska-Vassev, Katarzyna; Stojko, Jerzy; Klimek, Katarzyna; Olczyk, Monika; Kozma, Ewa M

2013-01-01

242

An atlas of active enhancers across human cell types and tissues  

NASA Astrophysics Data System (ADS)

Enhancers control the correct temporal and cell-type-specific activation of gene expression in multicellular eukaryotes. Knowing their properties, regulatory activity and targets is crucial to understand the regulation of differentiation and homeostasis. Here we use the FANTOM5 panel of samples, covering the majority of human tissues and cell types, to produce an atlas of active, in vivo-transcribed enhancers. We show that enhancers share properties with CpG-poor messenger RNA promoters but produce bidirectional, exosome-sensitive, relatively short unspliced RNAs, the generation of which is strongly related to enhancer activity. The atlas is used to compare regulatory programs between different cells at unprecedented depth, to identify disease-associated regulatory single nucleotide polymorphisms, and to classify cell-type-specific and ubiquitous enhancers. We further explore the utility of enhancer redundancy, which explains gene expression strength rather than expression patterns. The online FANTOM5 enhancer atlas represents a unique resource for studies on cell-type-specific enhancers and gene regulation.

Andersson, Robin; Gebhard, Claudia; Miguel-Escalada, Irene; Hoof, Ilka; Bornholdt, Jette; Boyd, Mette; Chen, Yun; Zhao, Xiaobei; Schmidl, Christian; Suzuki, Takahiro; Ntini, Evgenia; Arner, Erik; Valen, Eivind; Li, Kang; Schwarzfischer, Lucia; Glatz, Dagmar; Raithel, Johanna; Lilje, Berit; Rapin, Nicolas; Bagger, Frederik Otzen; Jørgensen, Mette; Andersen, Peter Refsing; Bertin, Nicolas; Rackham, Owen; Burroughs, A. Maxwell; Baillie, J. Kenneth; Ishizu, Yuri; Shimizu, Yuri; Furuhata, Erina; Maeda, Shiori; Negishi, Yutaka; Mungall, Christopher J.; Meehan, Terrence F.; Lassmann, Timo; Itoh, Masayoshi; Kawaji, Hideya; Kondo, Naoto; Kawai, Jun; Lennartsson, Andreas; Daub, Carsten O.; Heutink, Peter; Hume, David A.; Jensen, Torben Heick; Suzuki, Harukazu; Hayashizaki, Yoshihide; Müller, Ferenc; Consortium, The Fantom; Forrest, Alistair R. R.; Carninci, Piero; Rehli, Michael; Sandelin, Albin

2014-03-01

243

An atlas of active enhancers across human cell types and tissues.  

PubMed

Enhancers control the correct temporal and cell-type-specific activation of gene expression in multicellular eukaryotes. Knowing their properties, regulatory activity and targets is crucial to understand the regulation of differentiation and homeostasis. Here we use the FANTOM5 panel of samples, covering the majority of human tissues and cell types, to produce an atlas of active, in vivo-transcribed enhancers. We show that enhancers share properties with CpG-poor messenger RNA promoters but produce bidirectional, exosome-sensitive, relatively short unspliced RNAs, the generation of which is strongly related to enhancer activity. The atlas is used to compare regulatory programs between different cells at unprecedented depth, to identify disease-associated regulatory single nucleotide polymorphisms, and to classify cell-type-specific and ubiquitous enhancers. We further explore the utility of enhancer redundancy, which explains gene expression strength rather than expression patterns. The online FANTOM5 enhancer atlas represents a unique resource for studies on cell-type-specific enhancers and gene regulation. PMID:24670763

Andersson, Robin; Gebhard, Claudia; Miguel-Escalada, Irene; Hoof, Ilka; Bornholdt, Jette; Boyd, Mette; Chen, Yun; Zhao, Xiaobei; Schmidl, Christian; Suzuki, Takahiro; Ntini, Evgenia; Arner, Erik; Valen, Eivind; Li, Kang; Schwarzfischer, Lucia; Glatz, Dagmar; Raithel, Johanna; Lilje, Berit; Rapin, Nicolas; Bagger, Frederik Otzen; Jørgensen, Mette; Andersen, Peter Refsing; Bertin, Nicolas; Rackham, Owen; Burroughs, A Maxwell; Baillie, J Kenneth; Ishizu, Yuri; Shimizu, Yuri; Furuhata, Erina; Maeda, Shiori; Negishi, Yutaka; Mungall, Christopher J; Meehan, Terrence F; Lassmann, Timo; Itoh, Masayoshi; Kawaji, Hideya; Kondo, Naoto; Kawai, Jun; Lennartsson, Andreas; Daub, Carsten O; Heutink, Peter; Hume, David A; Jensen, Torben Heick; Suzuki, Harukazu; Hayashizaki, Yoshihide; Müller, Ferenc; Forrest, Alistair R R; Carninci, Piero; Rehli, Michael; Sandelin, Albin

2014-03-27

244

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

PubMed Central

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

Castro-Sanchez, Adelaida Maria; Moreno-Lorenzo, Carmen; Mataran-Penarrocha, Guillermo A.; Feriche-Fernandez-Castanys, Belen; Granados-Gamez, Genoveva; Quesada-Rubio, Jose Manuel

2011-01-01

245

Differential biological significance of tissue-type and urokinase-type plasminogen activator in human breast cancer.  

PubMed Central

Plasminogen activator (PA) is a serine protease existing in two forms known as tissue-type (t-PA) and urokinase-type (u-PA). To examine whether PA is related to the postoperative clinical course of human breast cancer, total PA activity, t-PA activity, u-PA activity, and immunoreactive t-PA were determined in tissue extracts from 144 breast cancer specimens. The patients were initially divided into four groups according to the postoperative clinical course: Group I (83 patients who are disease-free), Group II (20 patients whose first metastases were found only in bone), Group III (19 patients whose first metastases were found in both bone and lung), and Group IV (22 patients whose first metastases were found only in lung). Total PA activity was significantly lower in Groups, II, III and IV than in Group I. Both t-PA activity and t-PA antigen levels were also significantly lower in Groups II, III and IV than in Group I, while no significant difference was found in u-PA activity among these groups, indicating that low activity of total PA in Groups II, III and IV was due to a decrease in t-PA but not in u-PA. In the multivariate analyses, t-PA activity was found to be an independent prognostic factor for relapse-free survival. When four groups of patients were further analysed in terms of nodal status, both t-PA activity and antigen levels were markedly decreased in the node-negative Group II compared with the node-negative Groups III and IV or with the node-positive Groups II, III and IV. Of additional interest, u-PA activity was significantly higher in node-positive patients than in node-negative patients with any group. The clinico-pathologic analyses of the patients in this series showed that node involvement and lymphatic invasion were more frequently positive in Groups III and IV than in Groups I and II. When 144 breast cancers were categorised in terms of combinations of oestrogen receptor (ER) and progesterone receptor (PgR) status, breast cancers which were positive for both receptors were found to contain the highest t-PA activity and antigen. This study provides provocative evidence suggesting a possible differential significance of t-PA and u-PA expression in human breast cancer. PMID:8394731

Yamashita, J.; Ogawa, M.; Yamashita, S.; Nakashima, Y.; Saishoji, T.; Nomura, K.; Inada, K.; Kawano, I.

1993-01-01

246

Simulation of ultrasound backscatter images from fish  

NASA Astrophysics Data System (ADS)

The objective of this work is to investigate ultrasound (US) backscatter in the MHz range from fish to develop a realistic and reliable simulation model. The long term objective of the work is to develop the needed signal processing for fish species differentiation using US. In in-vitro experiments, a cod (Gadus morhua) was scanned with both a BK Medical ProFocus 2202 ultrasound scanner and a Toshiba Aquilion ONE computed tomography (CT) scanner. The US images of the fish were compared with US images created using the ultrasound simulation program Field II. The center frequency of the transducer is 10 MHz and the Full Width at Half Maximum (FWHM) at the focus point is 0.54 mm in the lateral direction. The transducer model in Field II was calibrated using a wire phantom to validate the simulated point spread function. The inputs to the simulation were the CT image data of the fish converted to simulated scatter maps. The positions of the point scatterers were assumed to be uniformly distributed. The scatter amplitudes were generated with a new method based on the segmented CT data in Hounsfield Units and backscatter data for the different types of tissues from the literature. The simulated US images reproduce most of the important characteristics of the measured US image.

Pham, An Hoai; Stage, Bjarne; Hemmsen, Martin Christian; Lundgren, Bo; Pedersen, Mads Møller; Pedersen, Tina Bock; Jensen, Jørgen Arendt

2011-03-01

247

Ultrasound characterization of the infertile male testis with rf power spectrum analysis  

NASA Astrophysics Data System (ADS)

Objective: To investigate and diagnose testicular pathology in patients with testicular dysfunction using the technique of ultrasound power spectrum analysis. Methods: Testicular ultrasound studies with power spectrum tissue characterization analysis were performed on men with testicular abnormalities as well as normal controls. Semen analysis, biopsy data, microscopic intra-operative findings and data pertaining to testicular function were collected for each surgically evaluated subject. Ultrasound data were analyzed for power spectrum characteristics of microscopic scatterer size and concentration within discrete areas of testicular tissue. Results: Patients with varicoceles and greater than 2x106 sperm/ml on semen analysis had larger average scatterer size (107.7 micrometers ) and lower scatterer concentration (-15.02 dB) than non-obstructed, azoospermic patients with varicoceles (92.4 micrometers and -11.41 dB, respectively). Subjects with obstructed azoospermia had slightly larger average tissue scatterer size (108.1 micrometers ) and lower concentration (-15.73 dB) while normal control data revealed intermediate values of size (102.3 micrometers ) and concentration (-13.1 dB) of scatterers. Spectral data from pure testicular seminoma lesions had the lowest average scatterer size (82.3 micrometers ) with low relative concentration (-14.7 dB). Summary: Ultrasound tissue characterization based on RF spectrum analysis may distinguish different types of testicular pathology including obstructed and non-obstructed azoospermia and tissue changes due to varicocele and tumor.

Coleman, Jonathan A.; Silverman, Ronald H.; Rondeau, Mark; Coleman, D. J.; Schlegel, Peter

2002-04-01

248

Tissue sorbitol concentration can be altered by changing the type of dietary carbohydrate or copper status  

SciTech Connect

This study was designed to determine whether rehabilitation of tissue sorbitol concentration occurs when rats consuming a high-fructose, low-copper diet are changed to diets containing starch or copper. Weanling male rats were provided with a diet which contained 62.7% fructose and 0.6 or 6.0 {mu}g Cu/g (F-Cu) for 4 weeks and then changed to either a fructose diet which contained 6.0 {mu}g Cu/g or a starch diet which contained either 0.6 or 6.0 {mu}g Cu/g for 2 weeks. Hepatic copper concentration of rats eating copper-deficient diets was about 30% of copper adequate rats regardless of the type of dietary carbohydrate. Pancreatic fructose, glucose and sorbitol concentrations were significantly lowered in rats changed to a starch diet. Kidney fructose and sorbitol concentrations were significantly lowered in rats changed to a starch diet. For all dietary groups, pancreatic and kidney sorbitol concentrations returned to normal after removal of rats from the F-Cu diet. In general, changing rats from a high-fructose, low-copper diet to a fructose diet with copper or a starch diet with or without copper improved the copper deficiency symptoms which changed in concert with tissue sorbitol levels.

Beal, T.; Lewis, C.G.; Fields, M. (Univ. of Maryland, College Park (USA))

1989-02-09

249

Measurement of human tissue-type plasminogen activator by a two-site immunoradiometric assay  

SciTech Connect

A two-site immunoradiometric assay for human extrinsic (tissue-type) plasminogen activator was developed by using rabbit antibodies raised against plasminogen activator purified from human melanoma cell culture fluid. Samples of 100 ..mu..l containing 1 to 100 ng/ml plasminogen activator were incubated in the wells of polyvinyl chloride microtiter plates coated with antibody. The amount of bound extrinsic plasminogen activator was quantitated by the subsequent binding of /sup 125/I-labeled affinospecific antibody. The mean level of plasma samples taken at rest was 6.6 +/- 2.9 ng/ml (n = 54). This level increased approximately threefold by exhaustive physical exercise, venous occlusion, or infusion of DDAVP. Extrinsic plasminogen activator in plasma is composed of a fibrin-adsorbable and active component (1.9 +/- 1.1 ng/ml, n = 54, in resting conditions) and an inactive component that does not bind to a fibrin clot (probably extrinsic plasminogen activator-proteinase inhibitor complexes). The fibrin-adsorbable fraction increased approximately fivefold to eightfold after physical exercise, venous occlusion, or DDAVP injections. Potential applications of the immunoradiometric assay are illustrated by the measurement of extrinsic plasminogen activator in different tissue extracts, body fluids, and cell culture fluids and in oocyte translation products after injection with mRNA for plasminogen activator.

Rijken, D.C. (Univ. of Leuven, Belgium); Juhan-Vague, I.; De Cock, F.; Collen, D.

1983-02-01

250

Balloon Type Elasticity Sensing of Left Ventricular Tissue for Small Experimental Animals  

NASA Astrophysics Data System (ADS)

This paper describes an elasticity sensing system for a left ventricular tissue of small experimental animal. We first show the basic concept of the proposed method, where a ring shaped specimen is dilated by a balloon type probe with pressure based control and the elasticity is estimated by using the stress and strain information. We introduce the dual cylinder model for approximating the strengths of material of the specimen and the balloon. Based on this model, we can derive the Young's modulus of the specimen. After showing the developed experimental system, we show basic experiments using silicone specimens. We finally show a couple of experimental results using rat and mouse, where specimens with HFPEF (Heart Failure with Preserved Ejection Fraction) can be separated from normal specimens.

Higashimori, Mitsuru; Ishii, Ryohei; Tadakuma, Kenjiro; Kaneko, Makoto; Tamaki, Syunsuke; Sakata, Yasushi; Yamamoto, Kazuhiro

251

Two-dimensional acoustic attenuation mapping of high-temperature interstitial ultrasound lesions  

NASA Astrophysics Data System (ADS)

Acoustic attenuation change in biological tissues with temperature and time is a critical parameter for interstitial ultrasound thermal therapy treatment planning and applicator design. Earlier studies have not fully explored the effects on attenuation of temperatures (75-95 °C) and times (5-15 min) common in interstitial ultrasound treatments. A scanning transmission ultrasound attenuation measurement system was devised and used to measure attenuation changes due to these types of thermal exposures. To validate the approach and to loosely define expected values, attenuation changes in degassed ex vivo bovine liver, bovine brain and chicken muscle were measured after 10 min exposures in a water bath to temperatures up to 90 °C. Maximum attenuation increases of approximately seven, four and two times the values at 37 °C were measured for the three tissue models at 5 MHz. By using the system to scan over lesions produced using interstitial ultrasound applicators, 2D contour maps of attenuation were produced. Attenuation profiles measured through the centrelines of lesions showed that attenuation was highest close to the applicator and decreased with radial distance, as expected with decreasing thermal exposure. Attenuation values measured in profiles through lesions were also shown to decrease with reduced power to the applicator. Attenuation increases in 2D maps of interstitial ultrasound lesions in ex vivo chicken breast, bovine liver and bovine brain were correlated with visible tissue coagulation. While regions of visible coagulation corresponded well to contours of attenuation increase in liver and chicken, no lesion was visible under the same experimental conditions in brain, due primarily to the heterogeneity of the tissue. Acoustic and biothermal simulations were employed to show that attenuation models taking into account these attenuation changes at higher temperatures and longer times were better able to fit experimental data than previous models. These simulations also indicated that the characterization of tissue acoustic and thermal properties over a large range of temperatures is critical for accurate treatment planning or design studies involving high-temperature interstitial ultrasound.

Tyréus, Per Daniel; Diederich, Chris

2004-02-01

252

Selenium and Vitamin E: Cell Type- and Intervention-Specific Tissue Effects in Prostate Cancer  

PubMed Central

Background Secondary analyses of two randomized, controlled phase III trials demonstrated that selenium and vitamin E could reduce prostate cancer incidence. To characterize pharmacodynamic and gene expression effects associated with use of selenium and vitamin E, we undertook a randomized, placebo-controlled phase IIA study of prostate cancer patients before prostatectomy and created a preoperative model for prostatectomy tissue interrogation. Methods Thirty-nine men with prostate cancer were randomly assigned to treatment with 200 ?g of selenium, 400 IU of vitamin E, both, or placebo. Laser capture microdissection of prostatectomy biopsy specimens was used to isolate normal, stromal, and tumor cells. Gene expression in each cell type was studied with microarray analysis and validated with a real-time polymerase chain reaction (PCR) and immunohistochemistry. An analysis of variance model was fit to identify genes differentially expressed between treatments and cell types. A beta-uniform mixture model was used to analyze differential expression of genes and to assess the false discovery rate. All statistical tests were two-sided. Results The highest numbers of differentially expressed genes by treatment were 1329 (63%) of 2109 genes in normal epithelial cells after selenium treatment, 1354 (66%) of 2051 genes in stromal cells after vitamin E treatment, and 329 (56%) of 587 genes in tumor cells after combination treatment (false discovery rate = 2%). Validation of 21 representative genes across all treatments and all cell types yielded Spearman correlation coefficients between the microarray analysis and the PCR validation ranging from 0.64 (95% confidence interval [CI] = 0.31 to 0.79) for the vitamin E group to 0.87 (95% CI = 0.53 to 0.99) for the selenium group. The increase in the mean percentage of p53-positive tumor cells in the selenium-treated group (26.3%), compared with that in the placebo-treated group (5%), showed borderline statistical significance (difference = 21.3%; 95% CI = 0.7 to 41.8; P = .051). Conclusions We have demonstrated the feasibility and efficiency of the preoperative model and its power as a hypothesis-generating engine. We have also identified cell type– and zone-specific tissue effects of interventions with selenium and vitamin E that may have clinical implications. PMID:19244175

Tsavachidou, Dimitra; McDonnell, Timothy J.; Wen, Sijin; Wang, Xuemei; Vakar-Lopez, Funda; Pisters, Louis L.; Pettaway, Curtis A.; Wood, Christopher G.; Do, Kim-Anh; Thall, Peter F.; Stephens, Clifton; Efstathiou, Eleni; Taylor, Robert; Menter, David G.; Troncoso, Patricia; Lippman, Scott M.; Logothetis, Christopher J.

2009-01-01

253

Troglitazone improves GLUT4 expression in adipose tissue in an animal model of obese type 2 diabetes mellitus  

Microsoft Academic Search

Troglitazone has been shown to improve peripheral insulin resistance in type 2 diabetic patients and animal models. We examined the effect of troglitazone on the expression of glucose transporter 4 (GLUT4) in muscle and adipose tissue from Otsuka Long–Evans Tokushima Fatty (OLETF) rat, an animal model of obese type 2 diabetes mellitus. In addition, the effects of troglitazone on GLUT4

Masahiko Furuta; Yutaka Yano; Esteban C. Gabazza; Rika Araki-Sasaki; Takashi Tanaka; Akira Katsuki; Yasuko Hori; Kaname Nakatani; Yasuhiro Sumida; Yukihiko Adachi

2002-01-01

254

Nonlinear modeling of therapeutic ultrasound  

Microsoft Academic Search

The authors describe experimental finite element modeling of tissue ablation by focused ultrasound. Emphasis is on nonlinear coupling of high intensity sound temperature, and tissue properties. The numerical basis for modeling nonlinearity is an incrementally linear, time-domain, finite element algorithm solving the electromechanical and bioheat equations in 2D\\/3D inhomogeneous elastic and acoustic media. Nonstandard modeling issues examined include harmonic generation\\/absorption

G. Wojcik; N. Abboud; M. Ostromogilsky; D. Vaughan

1995-01-01

255

Differential modulation of the functionality of white adipose tissue of obese Zucker (fa/fa) rats by the type of protein and the amount and type of fat.  

PubMed

Recent evidence indicates that several metabolic abnormalities developed during obesity are associated with the presence of dysfunctional adipose tissue. Diet is a key factor that modulates several functions of adipose tissue; however, each nutrient in the diet produces specific changes. Thus, the aim of this work was to study the effect of the interaction of the type (coconut or soybean oil) and amount (5% or 10%) of fat with the type of dietary protein (casein or soy protein) on the functionality of white adipose tissue of Zucker (fa/fa) rats. The results showed that soybean oil reduced adipocyte size and decreased esterified saturated fatty acids in white adipose tissue. Excess dietary fat also modified the composition of esterified fatty acids in white adipose tissue, increased the secretion of saturated fatty acids to serum from white adipose tissue and reduced the process of fatty acids re-esterification. On the other hand, soy protein sensitized the activation of the hormone-sensitive lipase by increasing the phosphorylation of this enzyme (Ser 563) despite rats fed soy protein were normoglucagonemic, in contrast with rats fed casein that showed hyperglucagonemia but reduced hormone-sensitive lipase phosphorylation. Finally, in white adipose tissue, the interaction between the tested dietary components modulated the transcription/translation process of lipid and carbohydrate metabolism genes via the activity of the PERK-endoplasmic reticulum stress response. Therefore, our results showed that the type of protein and the type and amount of dietary fat selectively modify the activity of white adipose tissue, even in a genetic model of obesity. PMID:23773624

Díaz-Villaseñor, Andrea; Granados, Omar; González-Palacios, Berenice; Tovar-Palacio, Claudia; Torre-Villalvazo, Ivan; Olivares-García, Verónica; Torres, Nimbe; Tovar, Armando R

2013-11-01

256

Biomaterials/scaffolds. Design of bioactive, multiphasic PCL/collagen type I and type II-PCL-TCP/collagen composite scaffolds for functional tissue engineering of osteochondral repair tissue by using electrospinning and FDM techniques.  

PubMed

Current clinical therapies for traumatic or chronic injuries involving osteochondral tissue result in temporary pain reduction and filling of the defect but with biomechanically inferior repair tissue. Tissue engineering of osteochondral repair tissue using autologous cells and bioactive biomaterials has the potential to overcome the current limitations and results in native-like repair tissue with good integration capabilities. For this reason, we applied two modem biomaterial design techniques, namely, electrospinning and fused deposition modeling (FDM), to produce bioactive poly(epsilon-caprolactone)/collagen (PCL/Col) type I and type II-PCL-tri-calcium phosphate (TCP)/Col composites for precursor cell-based osteochondral repair. The application of these two design techniques (electrospinning and FDM) allowed us to specifically produce the a suitable three-dimensional (3D) environment for the cells to grow into a particular tissue (cartilage and bone) in vitro prior to in vivo implantation. We hypothesize that our new designed biomaterials, seeded with autologous bone marrow-derived precursor cells, in combination with bioreactor-stimulated cell-culture techniques can be used to produce clinically relevant osteochondral repair tissue. PMID:18085205

Schumann, Detlef; Ekaputra, Andrew K; Lam, Christopher X F; Hutmacher, Dietmar W

2007-01-01

257

Low-frequency quantitative ultrasound imaging of cell death in vivo  

SciTech Connect

Purpose: Currently, no clinical imaging modality is used routinely to assess tumor response to cancer therapies within hours to days of the delivery of treatment. Here, the authors demonstrate the efficacy of ultrasound at a clinically relevant frequency to quantitatively detect changes in tumors in response to cancer therapies using preclinical mouse models.Methods: Conventional low-frequency and corresponding high-frequency ultrasound (ranging from 4 to 28 MHz) were used along with quantitative spectroscopic and signal envelope statistical analyses on data obtained from xenograft tumors treated with chemotherapy, x-ray radiation, as well as a novel vascular targeting microbubble therapy.Results: Ultrasound-based spectroscopic biomarkers indicated significant changes in cell-death associated parameters in responsive tumors. Specifically changes in the midband fit, spectral slope, and 0-MHz intercept biomarkers were investigated for different types of treatment and demonstrated cell-death related changes. The midband fit and 0-MHz intercept biomarker derived from low-frequency data demonstrated increases ranging approximately from 0 to 6 dBr and 0 to 8 dBr, respectively, depending on treatments administrated. These data paralleled results observed for high-frequency ultrasound data. Statistical analysis of ultrasound signal envelope was performed as an alternative method to obtain histogram-based biomarkers and provided confirmatory results. Histological analysis of tumor specimens indicated up to 61% cell death present in the tumors depending on treatments administered, consistent with quantitative ultrasound findings indicating cell death. Ultrasound-based spectroscopic biomarkers demonstrated a good correlation with histological morphological findings indicative of cell death (r{sup 2}= 0.71, 0.82; p < 0.001).Conclusions: In summary, the results provide preclinical evidence, for the first time, that quantitative ultrasound used at a clinically relevant frequency, in addition to high-frequency ultrasound, can detect tissue changes associated with cell death in vivo in response to cancer treatments.

Sadeghi-Naini, Ali; Falou, Omar; Czarnota, Gregory J. [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada) [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Department of Radiation Oncology, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Papanicolau, Naum; Tadayyon, Hadi [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada)] [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Lee, Justin [Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada)] [Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Zubovits, Judit [Department of Pathology, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada)] [Department of Pathology, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Sadeghian, Alireza [Department of Computer Science, Ryerson University, Toronto, Ontario M5B 2K3 (Canada)] [Department of Computer Science, Ryerson University, Toronto, Ontario M5B 2K3 (Canada); Karshafian, Raffi [Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3 (Canada)] [Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3 (Canada); Al-Mahrouki, Azza; Giles, Anoja [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada)] [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Kolios, Michael C. [Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5, Canada and Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3 (Canada)] [Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5, Canada and Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3 (Canada)

2013-08-15

258

Ultrasound Annual, 1984  

SciTech Connect

The 1984 edition of Ultrasound Annual explores new applications of ultrasound in speech and swallowing and offers guidelines on the use of ultrasound and nuclear medicine in thyroid and biliary tract disease. Other areas covered include Doppler sonography of the abdomen, intraoperative abdominal ultrasound, sonography of the placenta, ultrasound of the neonatal head and abdomen, and sonographic echo patterns created by fat.

Sanders, R.C.; Hill, M.C.

1984-01-01

259

Ontology-aware classification of tissue and cell-type signals in gene expression profiles across platforms and technologies  

PubMed Central

Motivation: Leveraging gene expression data through large-scale integrative analyses for multicellular organisms is challenging because most samples are not fully annotated to their tissue/cell-type of origin. A computational method to classify samples using their entire gene expression profiles is needed. Such a method must be applicable across thousands of independent studies, hundreds of gene expression technologies and hundreds of diverse human tissues and cell-types. Results: We present Unveiling RNA Sample Annotation (URSA) that leverages the complex tissue/cell-type relationships and simultaneously estimates the probabilities associated with hundreds of tissues/cell-types for any given gene expression profile. URSA provides accurate and intuitive probability values for expression profiles across independent studies and outperforms other methods, irrespective of data preprocessing techniques. Moreover, without re-training, URSA can be used to classify samples from diverse microarray platforms and even from next-generation sequencing technology. Finally, we provide a molecular interpretation for the tissue and cell-type models as the biological basis for URSA’s classifications. Availability and implementation: An interactive web interface for using URSA for gene expression analysis is available at: ursa.princeton.edu. The source code is available at https://bitbucket.org/youngl/ursa_backend. Contact: ogt@cs.princeton.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24037214

Lee, Young-suk; Krishnan, Arjun; Zhu, Qian; Troyanskaya, Olga G.

2013-01-01

260

A Prototype Ultrasound Instrument To Size Stone Fragments During Ureteroscopy  

NASA Astrophysics Data System (ADS)

An intraoperative tool to measure the size of kidney stones or stone fragments during ureteroscopy would help urologists assess if a fragment is small enough to be removed through the ureter or ureteral access sheath. The goal of this study was to determine the accuracy and precision of a prototype ultrasound device used to measure in vitro stone fragments compared to caliper measurements. A 10-MHz, 10-french ultrasound transducer probe was used to send an ultrasound pulse and receive ultrasound reflections from the stone using two methods. In Method 1 the instrument was aligned over the stone and the ultrasound pulse traveled through the stone. The time between reflections from the proximal and the distal surface of the stone were used along with the sound speed to calculate the stone size. Although the sound speed varied between stones, it was unlikely to be known during surgery and thus was estimated at 3000 m/s for calculations. In Method 2 the instrument was aligned partially over the stone and the ultrasound pulse traveled through water with a sound speed of 1481 m/s. Time was determined between the reflection from the proximal stone surface and the reflection from the tissue phantom on which the stone rested. Methods 1 and 2 were compared by linear regression to caliper measurements of the size of 19 human stones of 3 different stone types. Accuracy was measured by the difference of the mean ultrasound and mean caliper measurement and precision was measured as the standard deviation in the ultrasound measurements. For Method 1, the correlation between caliper-determined stone size and ultrasound-determined stone size was r2 = 0.71 (p<0.0001). In all but two stones accuracy and precision were less than 1 mm. For Method 2, the correlation was r2 = 0.99 (p<0.0001) and measurements were accurate and precise to within 0.25 mm. We conclude that the prototype device and either method measure stone size with good accuracy.

Sorensen, Mathew D.; Teichman, Joel M. H.; Bailey, Michael R.

2008-09-01

261

Exercise training does not improve myocardial diastolic tissue velocities in Type 2 diabetes  

PubMed Central

Background Myocardial diastolic tissue velocities are reduced already in newly onset Type 2 diabetes mellitus (T2D). Poor disease control may lead to left ventricular (LV) systolic dysfunction and heart failure. The aim of this study was to assess the effects of exercise training on myocardial diastolic function in T2D patients without ischemic heart disease. Methods 48 men (52.3 ± 5.6 yrs) with T2D were randomized to supervised training four times a week and standard therapy (E), or standard treatment alone (C) for 12 months. Glycated hemoglobin (HbA1c), oxygen consumption (VO2max), and muscle strength (Sit-up) were measured. Tissue Doppler Imaging (TDI) was used to determine the average maximal mitral annular early (Ea) and late (Aa) diastolic as well as systolic (Sa) velocities, systolic strain (?) and strain rate (?) from the septum, and an estimation of left ventricular end diastolic pressure (E/Ea). Results Exercise capacity (VO2max, E 32.0 to 34.7 vs. C 32.6 to 31.5 ml/kg/min, p = .001), muscle strength (E 12.7 to 18.3 times vs. C 14.6 to 14.7 times, p < .001), and HbA1c (E 8.2 to 7.5% vs. C 8.0 to 8.4%, p = .006) improved significantly in the exercise group compared to the controls (ANOVA). Systolic blood pressure decreased in the E group (E 144 to 138 mmHg vs. C 146 to 144 mmHg, p = .04). Contrary to risk factor changes diastolic long axis relaxation did not improve significantly, early diastolic velocity Ea from 8.1 to 7.9 cm/s for the E group vs. C 7.4 to 7.8 cm/s (p = .85, ANOVA). Likewise, after 12 months the mitral annular systolic velocity, systolic strain and strain rate, as well as E/Ea were unchanged. Conclusion Exercise training improves endurance and muscle fitness in T2D, resulting in better glycemic control and reduced blood pressure. However, myocardial diastolic tissue velocities did not change significantly. Our data suggest that a much longer exercise intervention may be needed in order to reverse diastolic impairment in diabetics, if at all possible. PMID:17897465

Loimaala, Antti; Groundstroem, Kaj; Rinne, Marjo; Nenonen, Arja; Huhtala, Heini; Vuori, Ilkka

2007-01-01

262

Adapting MRI acoustic radiation force imaging for in vivo human brain focused ultrasound applications.  

PubMed

A variety of magnetic resonance imaging acoustic radiation force imaging (MR-ARFI) pulse sequences as the means for image guidance of focused ultrasound therapy have been recently developed and tested ex vivo and in animal models. To successfully translate MR-ARFI guidance into human applications, ensuring that MR-ARFI provides satisfactory image quality in the presence of patient motion and deposits safe amount of ultrasound energy during image acquisition is necessary. The first aim of this work was to study the effect of motion on in vivo displacement images of the brain obtained with 2D Fourier transform spin echo MR-ARFI. Repeated bipolar displacement encoding configuration was shown less sensitive to organ motion. The optimal signal-to-noise ratio of displacement images was found for the duration of encoding gradients of 12 ms. The second aim was to further optimize the displacement signal-to-noise ratio for a particular tissue type by setting the time offset between the ultrasound emission and encoding based on the tissue response to acoustic radiation force. A method for measuring tissue response noninvasively was demonstrated. Finally, a new method for simultaneous monitoring of tissue heating during MR-ARFI acquisition was presented to enable timely adjustment of the ultrasound energy aimed at ensuring the safety of the MR-ARFI acquisition. PMID:22555751

Kaye, Elena A; Pauly, Kim Butts

2013-03-01

263

Breast biopsy - ultrasound  

MedlinePLUS

Biopsy - breast - ultrasound; Ultrasound-guided breast biopsy; Core needle breast biopsy - ultrasound ... care provider first cleans the area on your breast, and injects a numbing medicine. The doctor makes ...

264

Ultrasound guided supraclavicular block.  

PubMed

Ultrasound guided regional anaesthesia is becoming increasingly popular. The supraclavicular block has been transformed by ultrasound guidance into a potentially safe superficial block. We reviewed the techniques of performing supraclavicular block with special focus on ultrasound guidance. PMID:23979618

Hanumanthaiah, Deepak; Vaidiyanathan, Sabanayagam; Garstka, Maria; Szucs, Szilard; Iohom, Gabriella

2013-09-01

265

Venous Ultrasound (Extremities)  

MedlinePLUS

... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

266

General Ultrasound Imaging  

MedlinePLUS

... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

267

Percutaneous tenotomy: Development of a novel, percutaneous, ultrasound-guided needle-cutting technique for division of tendons and other connective tissue structures.  

PubMed

A variety of surgical procedures derive therapeutic benefit from the division of retinacular, ligamentous or tendinous structures. Examples include carpal tunnel release for median nerve impingement, annular pulley release for trigger finger and tendon division for spastic muscular contractures. Here, using an animal cadaveric model, we describe the first steps in determining the feasibility of a novel, percutaneous, ultrasound-guided needle-cutting technique to achieve the same ends. The technique we describe involves the creation of an effective needle tenotomy device via a simple modification to an 18G coaxial, beveled needle. The technique holds promise for the development of a minimally invasive alternative approach that utilises readily available technology and equipment with minimisation of morbidity and cost associated with open procedures. PMID:25088140

Hopkins, James; Sampson, Matthew

2014-06-01

268

Early intracardiac thrombosis in preterm infants and thrombolysis with recombinant tissue type plasminogen activator  

PubMed Central

OBJECTIVES—To determine the incidence of catheter related thrombosis and to test the efficacy of recombinant tissue type plasminogen activator (rt-PA) in preterm infants.?STUDY DESIGN—From January 1995 to December 1998, echocardiography was performed in the first few days of life in 76 very low birthweight (? 1500 g) infants out of a total of 147 having an umbilical catheter placed. When intracardiac thrombosis was diagnosed, rt-PA infusion was performed.?RESULTS—Four infants (5%) developed an intracardiac thrombosis during the first few days of life. In three of them, rt-PA at a dose of 0.4-0.5 mg/kg in a 20-30 minute bolus led to dissolution of the clot. One patient received a three hour infusion after the bolus, at a dose of 0.1 mg/kg/h, with resolution of the thrombus. No systemic effects were observed after rt-PA infusion.?CONCLUSIONS—Early thrombosis may occur as a complication of umbilical catheterisation in preterm infants; early echocardiographic detection of this disorder allows complete, safe, and rapid lysis with rt-PA.?? PMID:11420328

Ferrari, F; Vagnarelli, F; Gargano, G; Roversi, M; Biagioni, O; Ranzi, A; Cavazzuti, G

2001-01-01

269

Adipose tissue inflammation: feeding the development of type 2 diabetes mellitus.  

PubMed

The global increase in obesity-induced type 2 diabetes (T2DM) represents a burden for healthcare systems worldwide. Of particular concern is the increased morbidity associated with T2DM, in particular cardiovascular disease (CVD), leading to premature death. Obesity initially leads to the development of insulin resistance in adipose and other tissues. Insulin resistance is initially compensated by increased insulin secretion but ultimately insufficient insulin is produced and this leads to the development of T2DM. Understanding the causal mechanisms underpinning the development of obesity-induced insulin resistance may be beneficial in improving quality of life and life expectancy, with the potential for a major global impact on healthcare systems. There is abundant evidence from animal, human studies and in vitro studies to support functional roles for a number of inflammatory factors in obesity-induced insulin resistance. In this review we provide an overview of the evidence supporting a fundamental role for the fluid phase (in particular the complement system) and the cellular components of the innate immune system in the pathogenesis of obesity-induced insulin resistance and ultimately development of T2DM. PMID:23816302

Richardson, Victoria R; Smith, Kerrie A; Carter, Angela M

2013-12-01

270

Management of plastic bronchitis with topical tissue-type plasminogen activator.  

PubMed

Plastic bronchitis or cast bronchitis is a rare disease of unclear etiology characterized by formation of airway casts that can lead to life-threatening airway obstruction. There is currently limited data regarding optimal treatment of plastic bronchitis. Several therapies have been suggested, but recurrences are common and mortality remains high. We report the case of a 6-year-old boy with refractory eosinophilic bronchial casts, unresponsive to low-dose systemic corticosteroids, inhaled corticosteroids, azithromycin, and dornase alfa, who was treated successfully and safely with direct instillation of tissue-type plasminogen activator (tPA) to the obstructing casts during flexible bronchoscopy and inhaled tPA. Our case illustrates that the current therapy for plastic bronchitis remains inadequate. To our knowledge, this case is the first to show that direct instillation of tPA can be used safely for treatment of this disease. The use of tPA via direct administration into the airways during bronchoscopy and via a nebulizer appeared to be a safe and effective therapy for plastic bronchitis and should be considered early in the course of the disease to prevent complications of severe airway obstruction. PMID:22802609

Gibb, Elizabeth; Blount, Robert; Lewis, Nancy; Nielson, Dennis; Church, Gwynne; Jones, Kirk; Ly, Ngoc

2012-08-01

271

A novel function of tissue-type transglutaminase: protein disulphide isomerase.  

PubMed Central

We have found that tissue-type transglutaminase (tTG), also called TGc, TGase2 and Galpha(h), has the activity of protein disulphide isomerase (PDI). We have shown that tTG converts completely reduced/denatured inactive RNase A molecule to the native active enzyme. The PDI activity of tTG was strongly inhibited by bacitracin, which is a frequently used inhibitor of conventional PDI activity. It was substantially inhibited by the simultaneous presence of other potential substrate proteins such as completely reduced BSA, but not by native BSA. This activity was especially high in the presence of GSSG, but not GSH. The addition of GSH to the reaction mixture in the presence of GSSG at a fixed concentration up to at least 200-fold excess did not very substantially inhibit the PDI activity. It is possible that tTG can exert PDI activity in a fairly reducing environment like cytosol, where most of tTG is found. It is quite obvious from the following observations that PDI activity of tTG is catalysed by a domain different from that used for the transglutaminase reaction. Although the alkylation of Cys residues in tTG completely abolished the transglutaminase activity, as was expected, it did not affect the PDI activity at all. This PDI activity did not require the presence of Ca(2+). It was not inhibited by nucleotides including GTP at all, unlike the other activity of tTG. PMID:12737632

Hasegawa, Go; Suwa, Motoi; Ichikawa, Yasuo; Ohtsuka, Tetsuro; Kumagai, Satoru; Kikuchi, Masashi; Sato, Yoshitaka; Saito, Yuji

2003-01-01

272

Angle-dependent ultrasonic detection and imaging of two types of brachytherapy seeds using singular spectrum analysis.  

PubMed

Brachytherapy to treat prostate cancer uses transrectal ultrasound to guide implantation of titanium-shelled radioactive seeds. Transperitoneal implantation allows errors in placement that cause suboptimal dosimetry. Conventional ultrasound cannot reliably image implanted seeds; therefore, seed misplacements cannot be corrected in the operating room. Previously, an algorithm based on singular spectrum analysis was shown to image palladium seeds better than B-mode ultrasound could. The algorithm is now applied to imaging an iodine seed in gel and in beef tissue as a function of seed angle relative to the incident ultrasound. Results indicate that both seed types are imaged reliably by the algorithm. PMID:19206692

Mamou, Jonathan; Ramachandran, Sarayu; Feleppa, Ernest J

2008-12-01

273

Eye and orbit ultrasound  

MedlinePLUS

Echography - eye orbit; Ultrasound - eye orbit; Ocular ultrasonography; Orbital ultrasonography ... ophthalmology department of a hospital or clinic. Your eye is numbed with medicine (anesthetic drops). The ultrasound ...

274

Host protective roles of type 2 immunity: Parasite killing and tissue repair, flip sides of the same coin  

PubMed Central

Metazoan parasites typically induce a type 2 immune response, characterized by T helper 2 (Th2) cells that produce the cytokines IL-4, IL-5 and IL-13 among others. The type 2 response is host protective, reducing the number of parasites either through direct killing in the tissues, or expulsion from the intestine. Type 2 immunity also protects the host against damage mediated by these large extracellular parasites as they migrate through the body. At the center of both the innate and adaptive type 2 immune response, is the IL-4R? that mediates many of the key effector functions. Here we highlight the striking overlap between the molecules, cells and pathways that mediate both parasite control and tissue repair. We have proposed that adaptive Th2 immunity evolved out of our innate repair pathways to mediate both accelerated repair and parasite control in the face of continual assault from multicellular pathogens. Type 2 cytokines are involved in many aspects of mammalian physiology independent of helminth infection. Therefore understanding the evolutionary relationship between helminth killing and tissue repair should provide new insight into immune mechanisms of tissue protection in the face of physical injury. PMID:25028340

Allen, Judith E.; Sutherland, Tara E.

2014-01-01

275

Mechanical and histological characterization of trachea tissue subjected to blast-type pressures  

NASA Astrophysics Data System (ADS)

Injuries to the respiratory system can be a component of polytrauma in blast-loading injuries. Tissues located at air-liquid interfaces, including such tissues in the respiratory system, are particularly vulnerable to damage by blast overpressures. There is a lack of information about the mechanical and cellular responses that contribute to the damage of this class of tissues subjected to the high strain rates associated with blast loading. Here, we describe the results of dynamic blast-like pressure loading tests at high strain rates on freshly harvested ex vivo trachea tissue specimens.

Butler, B. J.; Bo, C.; Tucker, A. W.; Jardine, A. P.; Proud, W. G.; Williams, A.; Brown, K. A.

2014-05-01

276

Predictors of epicardial adipose tissue in patients with type 2 diabetes mellitus  

PubMed Central

Background Epicardial adipose tissue (EAT), visceral fat depot of the heart, was found to be associated with coronary artery disease in cardiac and non-cardiac patients. Platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) were introduced as potential markers to determine inflammation in various disorders. Recently, atherogenic index of plasma (AIP) was found to be closely associated with atherosclerosis in general population. Waist circumference is commonly used to assess the risk factors in various metabolic disorders. There has been a well known relation between inflammation and peripheral adipose tissue in diabetes mellitus. However, the data regarding EAT and inflammation is scant in this population. Hence, we aimed to determine the relationship between PLR, NLR, AIP, waist circumference and EAT in diabetic patients. Methods This was a cross-sectional study involving 156 patients with type 2 diabetes mellitus (87 females, 69 males; mean age, 53.62?±?9.33 years) and 50 control subjects (35 females, 15 males; mean age, 51.06?±?8.74 years). EAT was measured by using a trans-thoracic echocardiogram. Atherogenic index of plasma was calculated as the logarithmically transformed ratio of the serum triglyceride to high density lipoprotein (HDL)cholesterol. NLR and PLR were calculated as the ratio of the neutrophils and platelets to lymphocytes, respectively. Results Waist circumference, PLR, NLR, AIP and EAT measurements were significantly higher in diabetic patients when compared to control subjects. When diabetic patients were separated into two groups according to their median value of EAT (Group 1, EAT?

2014-01-01

277

Ultrasound Guidance and Monitoring of Laser-Based Fat Removal  

PubMed Central

Background and Objectives We report on a study to investigate feasibility of utilizing ultrasound imaging to guide laser removal of subcutaneous fat. Ultrasound imaging can be used to identify the tissue composition and to monitor the temperature increase in response to laser irradiation. Study Design/Materials and Methods Laser heating was performed on ex vivo porcine subcutaneous fat through the overlying skin using a continuous wave laser operating at 1,210 nm optical wavelength. Ultrasound images were recorded using a 10 MHz linear array-based ultrasound imaging system. Results Ultrasound imaging was utilized to differentiate between water-based and lipid-based regions within the porcine tissue and to identify the dermis-fat junction. Temperature maps during the laser exposure in the skin and fatty tissue layers were computed. Conclusions Results of our study demonstrate the potential of using ultrasound imaging to guide laser fat removal. PMID:19065554

Shah, Jignesh; Thomsen, Sharon; Milner, Thomas E.; Emelianov, Stanislav Y.

2009-01-01

278

The tissue microarray data exchange specification: A document type definition to validate and enhance XML data  

Microsoft Academic Search

BACKGROUND: The Association for Pathology Informatics (API) Extensible Mark-up Language (XML) TMA Data Exchange Specification (TMA DES) proposed in April 2003 provides a community-based, open source tool for sharing tissue microarray (TMA) data in a common format. Each tissue core within an array has separate data including digital images; therefore an organized, common approach to produce, navigate and publish such

David G Nohle; Leona W Ayers

2005-01-01

279

A novel approach in personal identification from tissue samples undergone different processes through STR typing  

Microsoft Academic Search

Short tandem repeats (STRs) or microsatellites have been recognized worldwide as a powerful tool for human identification. They have become widely used in human identification especially in criminal cases and mass disasters. Police departments are often interested in cases where tissues are already decomposed and only do bones remain to let them perform laboratory analyses.Bone is the most resistant tissue

N. Staiti; D. Di Martino; L. Saravo

2004-01-01

280

Ultrasound echoes as biometric navigators.  

PubMed

We demonstrate a new method of using ultrasound data to achieve prospective motion compensation in MRI, especially for respiratory motion during interventional MRI procedures in moving organs such as the liver. The method relies on fingerprint-like biometrically distinct ultrasound echo patterns produced by different locations in tissue, which are collated with geometrical information from MRI during a training stage to form a mapping table that relates ultrasound measurements to positions. During prospective correction, the system makes frequent ultrasound measurements and uses the map to determine the corresponding position. Results in motorized linear motion phantoms and freely breathing animals indicate that the system performs well. Apparent motion is reduced by up to 97.8%, and motion artifacts are reduced or eliminated in two-dimensional spoiled gradient-echo images. The motion compensation is sufficient to permit MRI thermometry of focused ultrasound heating during respiratory-like motion, with results similar to those obtained in the absence of motion. This new technique may have applications for MRI thermometry and other dynamic imaging in the abdomen during free breathing. PMID:22648783

Schwartz, Benjamin M; McDannold, Nathan J

2013-04-01

281

Ultrasound Echoes as Biometric Navigators  

PubMed Central

We demonstrate a new method of using ultrasound data to achieve prospective motion compensation in MRI, especially for respiratory motion during interventional MRI procedures in moving organs such as the liver. The method relies on fingerprint-like biometrically distinct ultra-sound echo patterns produced by different locations in tissue, which are collated with geometrical information from MRI during a training stage to form a mapping table that relates ultrasound measurements to positions. During prospective correction, the system makes frequent ultrasound measurements and uses the map to determine the corresponding position. Results in motorized linear motion phantoms and freely breathing animals indicate that the system performs well. Apparent motion is reduced by up to 97.8%, and motion artifacts are reduced or eliminated in 2D Spoiled Gradient-Echo images. The motion compensation is sufficient to permit MRI thermometry of focused ultrasound heating during respiratory-like motion, with results similar to those obtained in the absence of motion. This new technique may have applications for MRI thermometry and other dynamic imaging in the abdomen during free breathing. PMID:22648783

Schwartz, Benjamin M.; McDannold, Nathan J.

2014-01-01

282

Endoscopic Ultrasound-Assisted Tunnel-Type Endoscopic Submucosal Dissection for the Treatment of Esophageal Tumors Arising in the Muscularis Propria (with video)  

PubMed Central

Objective: Esophageal tumors arising in the muscularis propria are difficult to be resected endoscopically using standard electro-surgical techniques, even the endoscopic submucosal dissection (ESD) technique appeared recently. Our purpose is to investigate the efficacy of endoscopic ultrasound (EUS)-assisted tunnel-type ESD for resection of these tumors. Methods: A total of 17 patients were included in this study. A standard endoscope was used. The submucosal tunnel was created with the triangle knife according to the standard ESD technique, about 5 cm proximal to the lesion. EUS was performed within the tunnel to detect the tumor, and then the tumor was separated both from the submucosal and the muscle layers. After the tumor was removed, several clips were used to close the mucosal defect. EUS was performed to evaluate the healing quality 1 week after the procedure. Result: In all the cases, the tumors were completely resected. Mean tumor size was 24.2 mm (12-50 mm) in diameter. The histo-logical diagnoses were leiomyoma (16/17) and gastrointestinal stromal tumor (GIST, 1/17). Subcutaneous emphysema was found in 2 patients after the procedure, but disappeared by the third day. No patients sustained perforation or developed significant hem-orrhage, and there were no other immediate severe complications after the procedure. The healing quality was satisfying in 16/17 patients evaluated by EUS 1 week after the procedure. No recurrence has been found during follow-up (mean 7 months, range 3-13 months). Conclusion: EUS-assisted tunnel-type ESD is effective and safe in treatment of esophageal tumors arising in the muscularis pro-pria. PMID:24949361

Ge, Nan; Sun, Siyu; Wang, Sheng; Liu, Xiang; Wang, Guoxin; Guo, Jintao

2013-01-01

283

Pharmacokinetics and thrombolytic effects of the recombinant tissue-type plasminogen activator in horses  

PubMed Central

Background To test the efficacy of the recombinant tissue-type plasminogen activator (rt-PA) alteplase in horses, the thrombolytic effect was tested in in vitro generated equine thrombi. The extent of lysis was determined by measuring the decrease in thrombi weight over a period of 4 hours. In vivo pharmacokinetics of alteplase were determined in 6 healthy horses. A single dose (1 mg/kg) was applied via intravenous infusion over a period of 30 minutes Coagulation-related variables, blood count and clinical parameters were taken before the treatment and until 48 h after treatment. In addition, plasma rt-PA concentration was measured until 300 min after commencing the infusion. Results In vitro, a dose dependent decrease of thrombus weight ranging from a 56 (± 6.5) % decrease for 0.5 ?g/ml to 92 (± 2.1) % decrease for 5 ?g/ml rt-PA was noted. The D-dimer concentration in the lysis medium correspondingly increased from 0.10 up to 10.8 mg/l. In vivo, none of the horses showed an adverse reaction to the alteplase infusion. In some horses blood parameters were slightly altered. The 1 mg/kg dose yielded the following pharmacokinetic parameters: Cmax = 1.25?±?0.27 ?g/ml; CL = 21.46?±?5.67 ml/min/kg; dominant half life (t1/2?) = 6.81?±?1.48 minutes; median elimination half life (t1/2?) = 171 min (range: 85–1061); AUC = 50.33?±?17.62 ?g?·?min /ml. Conclusion These findings indicate that a single dose of 1 mg/kg alteplase results in rt-PA plasma concentrations comparable to those in humans and might be sufficient for a thrombolytic therapy in horses. Further studies must be performed to determine the alteplase effectiveness in horses with jugular vein thrombosis. PMID:23938183

2013-01-01

284

Lead in tissues of mallard ducks dosed with two types of lead shot  

USGS Publications Warehouse

Mallard ducks (Anas platyrhynchos) were sacrificed one month after ingesting one number 4 all-lead shot or one number 4 lead-iron shot. Livers, kidneys, blood, wingbones, and eggs were analyzed for lead by atomic absorption. Necropsy of sacrificed ducks failed to reveal any of the tissue lesions usually associated with lead poisoning in waterfowl. Lead levels in ducks given all-lead shot averaged about twice those in ducks given lead-iron shot, reflecting the amount of lead in the two types of shot. Lead in the blood of ducks dosed with all-lead shot averaged 0.64 ppm, and 0.28 ppm in ducks given lead-iron shot. Lead residues in livers and kidneys of females given all-lead shot were significantly higher than in males. In both dosed groups, lead levels in wingbones of females were about 10 times those in males, and were significantly correlated with the number of eggs laid after dosage. Lead levels in contents and shells of eggs laid by hens dosed with all-lead shot were about twice those in eggs laid by hens dosed with lead-iron shot. Eggshells were found to best reflect levels of lead in the blood. Our results indicate that mallards maintained on a balanced diet and dosed with one lead shot may not accumulate extremely high lead levels in the liver and kidney. However, extremely high lead deposition may result in the bone of laying hens after ingesting sublethal amounts of lead shot as a result of mobilization of calcium from the bone during eggshell formation.

Finley, M.T.; Dieter, M.P.; Locke, L.N.

1976-01-01

285

Dehydroepiandrosterone reduces plasma plasminogen activator inhibitor type 1 and tissue plasminogen activator antigen in men.  

PubMed

Dehydroepiandrosterone (DHEA) may help prevent heart disease in men. To test the hypothesis that DHEA might exert its effects by enhancing endogenous fibrinolytic potential, a double-blind, placebo-controlled study was conducted that assessed the effects of DHEA administration on plasma plasminogen activator inhibitor type 1 (PAI-1) and tissue plasminogen activator (tPA) antigen. Eighteen men received 50 mg DHEA orally and 16 men received a placebo capsule thrice daily for 12 days. Serum DHEA-sulfate and plasma PAI-1 and tPA antigen were measured before and after treatment. In the DHEA group, serum DHEA-sulfate (from 7.5 +/- 1.2 micromol/L to 20.2 +/- 1.5 micromol/L (P < 0.0001), androstenedione (from 2.6 +/- 0.2 nmol/L to 4.0 +/- 0.4 nmol/L; P < 0.005) and estrone (from 172 +/- 21 pmol/L to 352 +/- 28 pmol/L; P < 0.005) increased, whereas plasma PAI-1 (from 55.4 +/- 3.8 ng/mL to 38.6 +/- 3.3 ng/mL; P < 0.0001) and tPA antigen (from 8.1 +/- 1.9 ng/mL to 5.4 +/- 1.3 ng/mL; P < 0.0005) decreased. In the placebo group, serum DHEA-sulfate declined slightly from 8.0 +/- 3.3 micromol/L to 7.3 +/- 3.4 micromol/L (P < 0.05), but no other measured steroid changed. Plasma PAI-1 and tPA antigen did not change in the placebo group. These findings suggest that DHEA administration reduces plasma PAI-1 and tPA antigen concentrations in men. PMID:8615394

Beer, N A; Jakubowicz, D J; Matt, D W; Beer, R M; Nestler, J E

1996-05-01

286

Analysis of artificial radiocarbon in different skeletal and dental tissue types to evaluate date of death.  

PubMed

Radiocarbon dating, with special reference to the modern bomb-curve, can provide useful information to elucidate the date of death of skeletonized human remains. Interpretation can be enhanced with analysis of different types of tissues within a single skeleton because of the known variability of formation times and remodeling rates. Analysis of radiocarbon content of teeth, especially the enamel in tooth crowns, provides information about the date of formation in the childhood years and in consideration of the known timing of tooth formation can be used to estimate the birth date after 1950 ad. Radiocarbon analysis of modern cortical and trabecular bone samples from the same skeleton may allow proper placement on the pre-1963 or post-1963 sides of the bomb-curve as most trabecular bone generally undergoes more rapid remodeling than does most cortical bone. Pre-1963 bone formation would produce higher radiocarbon values for most trabecular bone than for most cortical bone. This relationship is reversed for formation after 1963. Radiocarbon analysis was conducted in this study on dental, cortical, and trabecular bone samples from two adult individuals of known birth (1925 and 1926) and death dates (1995 and 1959). As expected, the dental results correspond to prebomb-curve values reflecting conditions during the childhoods of the individuals. The radiocarbon content of most bone samples reflected the higher modern bomb-curve values. Within the bone sample analyses, the values of the trabecular bone were higher than those of cortical bone and supported the known placement on the pre-1963 side of the bomb-curve. PMID:16696693

Ubelaker, Douglas H; Buchholz, Bruce A; Stewart, John E B

2006-05-01

287

Analysis of Artificial Radiocarbon in Different Skeletal and Dental Tissue Types to Evaluate Date of Death  

SciTech Connect

Radiocarbon dating, with special reference to the modern bomb-curve, can provide useful information to elucidate the date of death of skeletonized human remains. Interpretation can be enhanced with analysis of different types of tissues within a single skeleton because of the known variability of formation times and remodeling rates. Analysis of radiocarbon content of teeth, especially the enamel in tooth crowns provides information about the date of formation in the childhood years and in consideration of the known timing of tooth formation can be used to estimate the birth date after 1950 A.D. Radiocarbon analysis of modern cortical and trabecular bone samples from the same skeleton may allow proper placement on the pre-1963 or post-1963 sides of the bomb-curve since most trabecular bone generally undergoes more rapid remodeling than does most cortical bone. Pre-1963 bone formation would produce higher radiocarbon values for most trabecular bone than for most cortical bone. This relationship is reversed for formation after 1963. Radiocarbon analysis was conducted in this study on dental, cortical and trabecular bone samples from two adult individuals of known birth (1925 and 1926) and death dates (1995 and 1959). As expected, the dental results correspond to pre-bomb bomb-curve values reflecting conditions during the childhoods of the individuals. The curve radiocarbon content of most bone samples reflected the higher modern bomb-curve values. Within the bone sample analyses, the values of the trabecular bone were higher than those of cortical bone and supported the known placement on the pre-1963 side of the bomb-curve.

Ubelaker, D H; Buchholz, B A; Stewart, J

2005-07-19

288

[The change of thioredoxin system in myocardial tissue of type 2 diabetic rats undergoing myocardial injury].  

PubMed

The aim of the present study is to investigate the change of thioredoxin (Trx) system in myocardial tissue of type 2 diabetic rats after myocardial injury and the underlying mechanism. Adult Sprague Dawley rats were randomly divided into two groups: normal control (NC) group and diabetes (DM) group. Rats in DM group were subjected to high-sugar, high-fat diet and streptozotocin (STZ) injection. Rats in NC group were only given normal diet and equal amount of citric acid buffer injection. At week 1, 2, 4, 12, 21 after STZ injection, plasma glucose concentration and the concentrations of insulin, creatine kinase MB (CK-MB), cardiac troponin I (cTnI) in serum were measured. Myocardial Trx and thioredoxin reductase (TR) activities, as well as caspase-3 activity, were determined by respective assay methods. Protein and mRNA levels of Trx, TR, Trx interacting protein (TXNIP) were determined by Western blot and real time PCR, respectively. The results showed that type 2 diabetic rat model was successfully established at week 1 after STZ injection, and myocardial injury was induced from week 2. Moreover, caspase-3 activity was significantly increased at week 4, 12 in diabetic rats. The activities of myocardial Trx and TR in diabetic rats was decreased from week 2, and continually aggravated as the disease developed. Compared with those in NC group, the mRNA levels of Trx1, Trx2, TR1, TR2 in DM group decreased at week 4, and then increased in week 12. In DM group, the protein levels of Trx1, Trx2, TR1 and TR2 increased significantly at week 12. The mRNA expressions of myocardial TXNIP in diabetic rats were significantly increased at week 4, 12, 24 and protein expression was increased at week 12. These results suggest diabetes can decrease myocardial Trx, TR activity, inducing myocardial cell apoptosis and heart injury. The inhibitory effect of diabetes is mainly associated with TXNIP up-regulation and Trx nitration. PMID:20571744

Zhao, Xiao-Qin; Zhao, Jun-Jie; Li, Xiao-Yu; Zhang, Yan; Jiao, Xiang-Ying

2010-06-25

289

Treating Cancer with Strong Magnetic Fields and Ultrasound  

E-print Network

It is proposed to treat cancer by the combination of a strong magnetic field with intense ultrasound. At the low electrical conductivity of tissue the magnetic field is not frozen into the tissue, and oscillates against the tissue which is brought into rapid oscillation by the ultrasound. As a result, a rapidly oscillating electric field is induced in the tissue, strong enough to disrupt cancer cell replication. Unlike radio frequency waves, which have been proposed for this purpose, ultrasound can be easily focused onto the regions to be treated. This method has the potential for the complete eradication of the tumor.

Dr. Friedwardt Winterberg

2009-06-03

290

Detection of Curved Robots using 3D Ultrasound  

PubMed Central

Three-dimensional ultrasound can be an effective imaging modality for image-guided interventions since it enables visualization of both the instruments and the tissue. For robotic applications, its realtime frame rates create the potential for image-based instrument tracking and servoing. These capabilities can enable improved instrument visualization, compensation for tissue motion as well as surgical task automation. Continuum robots, whose shape comprises a smooth curve along their length, are well suited for minimally invasive procedures. Existing techniques for ultrasound tracking, however, are limited to straight, laparoscopic-type instruments and thus are not applicable to continuum robot tracking. Toward the goal of developing tracking algorithms for continuum robots, this paper presents a method for detecting a robot comprised of a single constant curvature in a 3D ultrasound volume. Computational efficiency is achieved by decomposing the six-dimensional circle estimation problem into two sequential three-dimensional estimation problems. Simulation and experiment are used to evaluate the proposed method. PMID:22229110

Ren, Hongliang; Vasilyev, Nikolay V.; Dupont, Pierre E.

2011-01-01

291

Portable Bladder Ultrasound  

PubMed Central

Executive Summary Objective The aim of this review was to assess the clinical utility of portable bladder ultrasound. Clinical Need: Target Population and Condition Data from the National Population Health Survey indicate prevalence rates of urinary incontinence are 2.5% in women and 1.4 % in men in the general population. Prevalence of urinary incontinence is higher in women than men and prevalence increases with age. Identified risk factors for urinary incontinence include female gender, increasing age, urinary tract infections (UTI), poor mobility, dementia, smoking, obesity, consuming alcohol and caffeine beverages, physical activity, pregnancy, childbirth, forceps and vacuum-assisted births, episiotomy, abdominal resection for colorectal cancer, and hormone replacement therapy. For the purposes of this review, incontinence populations will be stratified into the following; the elderly, urology patients, postoperative patients, rehabilitation settings, and neurogenic bladder populations. Urinary incontinence is defined as any involuntary leakage of urine. Incontinence can be classified into diagnostic clinical types that are useful in planning evaluation and treatment. The major types of incontinence are stress (physical exertion), urge (overactive bladder), mixed (combined urge and stress urinary incontinence), reflex (neurological impairment of the central nervous system), overflow (leakage due to full bladder), continuous (urinary tract abnormalities), congenital incontinence, and transient incontinence (temporary incontinence). Postvoid residual (PVR) urine volume, which is the amount of urine in the bladder immediately after urination, represents an important component in continence assessment and bladder management to provide quantitative feedback to the patient and continence care team regarding the effectiveness of the voiding technique. Although there is no standardized definition of normal PVR urine volume, measurements greater than 100 mL to 150 mL are considered an indication for urinary retention, requiring intermittent catheterization, whereas a PVR urine volume of 100 mL to 150 mL or less is generally considered an acceptable result of bladder training. Urinary retention has been associated with poor outcomes including UTI, bladder overdistension, and higher hospital mortality rates. The standard method of determining PVR urine volumes is intermittent catheterization, which is associated with increased risk of UTI, urethral trauma and discomfort. The Technology Being Reviewed Portable bladder ultrasound products are transportable ultrasound devices that use automated technology to register bladder volume digitally, including PVR volume, and provide three-dimensional images of the bladder. The main clinical use of portable bladder ultrasound is as a diagnostic aid. Health care professionals (primarily nurses) administer the device to measure PVR volume and prevent unnecessary catheterization. An adjunctive use of the bladder ultrasound device is to visualize the placement and removal of catheters. Also, portable bladder ultrasound products may improve the diagnosis and differentiation of urological problems and their management and treatment, including the establishment of voiding schedules, study of bladder biofeedback, fewer UTIs, and monitoring of potential urinary incontinence after surgery or trauma. Review Strategy To determine the effectiveness and clinical utility of portable bladder ultrasound as reported in the published literature, the Medical Advisory Secretariat used its standard search strategy to retrieve international health technology assessments and English-language journal articles from selected databases. Nonsystematic reviews, nonhuman studies, case reports, letters, editorials, and comments were excluded. Summary of Findings Of the 4 included studies that examined the clinical utility of portable bladder ultrasound in the elderly population, all found the device to be acceptable. One study reported that the device underestimated catheterized bladder volume In patients with urology

2006-01-01

292

Methylation quantitative trait loci (meQTLs) are consistently detected across ancestry, developmental stage, and tissue type  

PubMed Central

Background Individual genotypes at specific loci can result in different patterns of DNA methylation. These methylation quantitative trait loci (meQTLs) influence methylation across extended genomic regions and may underlie direct SNP associations or gene-environment interactions. We hypothesized that the detection of meQTLs varies with ancestral population, developmental stage, and tissue type. We explored this by analyzing seven datasets that varied by ancestry (African American vs. Caucasian), developmental stage (neonate vs. adult), and tissue type (blood vs. four regions of postmortem brain) with genome-wide DNA methylation and SNP data. We tested for meQTLs by constructing linear regression models of methylation levels at each CpG site on SNP genotypes within 50 kb under an additive model controlling for multiple tests. Results Most meQTLs mapped to intronic regions, although a limited number appeared to occur in synonymous or nonsynonymous coding SNPs. We saw significant overlap of meQTLs between ancestral groups, developmental stages, and tissue types, with the highest rates of overlap within the four brain regions. Compared with a random group of SNPs with comparable frequencies, meQTLs were more likely to be 1) represented among the most associated SNPs in the WTCCC bipolar disorder results and 2) located in microRNA binding sites. Conclusions These data give us insight into how SNPs impact gene regulation and support the notion that peripheral blood may be a reliable correlate of physiological processes in other tissues. PMID:24555763

2014-01-01

293

Update on ultrasound elastography: miscellanea. Prostate, testicle, musculo-skeletal.  

PubMed

Nowadays ultrasound elastosonography is an established technique, although with limited clinical application, used to assess tissue stiffness, which is a parameter that in most cases is associated with malignancy. However, although a consistent number of articles have been published about several applications of elastosonography, its use in certain human body districts is still not well defined. In this paper we write on the use of elastosonography in prostate, testicle and musculo-skeletal apparatus. We report and compare the work of several authors, different type of elastosonography (shear wave, strain elastography, etc.) and instrumental data obtained in the study of both benign and malignant lesions. PMID:23816164

Correas, J M; Drakonakis, E; Isidori, A M; Hélénon, O; Pozza, C; Cantisani, V; Di Leo, N; Maghella, F; Rubini, A; Drudi, F M; D'ambrosio, F

2013-11-01

294

siRNA-targeting transforming growth factor-? type I receptor reduces wound scarring and extracellular matrix deposition of scar tissue.  

PubMed

Hypertrophic scarring is related to persistent activation of transforming growth factor-? (TGF-?)/Smad signaling. In the TGF-?/Smad signaling cascade, the TGF-? type I receptor (TGFBRI) phosphorylates Smad proteins to induce fibroblast proliferation and extracellular matrix deposition. In this study, we inhibited TGFBRI gene expression via TGFBRI small interfering RNA (siRNA) to reduce fibroblast proliferation and extracellular matrix deposition. Our results demonstrate that downregulating TGFBRI expression in cultured human hypertrophic scar fibroblasts significantly suppressed cell proliferation and reduced type I collagen, type III collagen, fibronectin, and connective tissue growth factor (CTGF) mRNA, and type I collagen and fibronectin protein expression. In addition, we applied TGFBRI siRNA to wound granulation tissue in a rabbit model of hypertrophic scarring. Downregulating TGFBRI expression reduced wound scarring, the extracellular matrix deposition of scar tissue, and decreased CTGF and ?-smooth muscle actin mRNA expression in vivo. These results suggest that TGFBRI siRNA could be applied clinically to prevent hypertrophic scarring. PMID:24670383

Wang, Yi-Wen; Liou, Nien-Hsien; Cherng, Juin-Hong; Chang, Shu-Jen; Ma, Kuo-Hsing; Fu, Earl; Liu, Jiang-Chuan; Dai, Niann-Tzyy

2014-07-01

295

Subcutaneous connective tissue reactions to three types of bioactive glass nanopowders.  

PubMed

Silica-based bioactive glasses are considered promising bone substitutes and tissue regeneration matrices, because of their bioactivity, biocompatibility, osteoconductivity, and possibly even osteoinductivity. The aim of this work was to evaluate the subcutaneous connective tissue reactions to 58S, 63S, and 72S bioactive glass nanopowders. Our previous study showed the antibacterial activities of 58S and 63S bioactive glass nanopowders on aerobic bacteria, while 72S showed no antibacterial effects at all. Bioactive glass nanopowders were prepared via the sol-gel technique. Characterization techniques such as X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and X-ray fluorescent (XRF) were utilized to carry out the phase analysis, study of the structure, particle size and the composition of the synthesized bioactive glasses. To evaluate the subcutaneous connective tissue reactions, the specimens were placed in polyethylene tubes and implanted into the dorsal connective tissue of rats. Empty polyethylene tubes were used as the control and bioactive glass micropowders (NovaBone) was used as a FDA approved bone graft. The evaluation of inflammatory reactions was performed 3, 7, 15, and 28 days after implantation. Results showed a particle size of below 100 nm for samples with amorphous structure. The samples were well tolerated by the tissues over a 28-day evaluation period. The extra tissue reactions of the 72S specimen in comparison with 58S and 63S specimens could be attributed to its higher silica content. It may be concluded that biocompatible 58S and 63S bioactive glass nanopowders with antibacterial activities can be synthesized for the treatment of osseous defects. PMID:21830490

Mehdikhani-Nahrkhalajil, M; Fathi, M H; Mortazavi, V; Mousavi, S B; Razavi, S M

2011-06-01

296

Adipose tissue distribution in relation to insulin sensitivity and inflammation in Pakistani and Norwegian subjects with type 2 diabetes.  

PubMed

Abstract Immigrants from South Asia to Western countries have a high prevalence of type 2 diabetes mellitus (T2DM) associated with obesity. We investigated the relationship between diabetes and adipose tissue distribution in a group of younger T2DM subjects from Norway and Pakistan. Eighteen immigrant Pakistani and 21 Norwegian T2DM subjects (age 29-45, 49% men) were included. They underwent anthropometrical measurements including bioelectrical impedance analysis, CT scans measuring fatty infiltration in liver and adipose and muscle tissue compartments in mid-abdomen and thigh, a euglycemic clamp, and blood samples for serum insulin and plasma glucose, adipokines and inflammation markers. Adipose tissue distribution was similar in Norwegians and Pakistanis. Pakistanis, but not Norwegians, showed a negative correlation between insulin sensitivity and visceral adipose tissue (VAT, rs = - 0.704, p = 0.003). Subcutaneous adipose tissue (SAT) correlated to leptin in both Pakistanis and Norwegians (rs = 0.88, p < 0.001 and 0.67, p = 0.001). SAT also correlated to C-reactive protein (CRP) in the Pakistanis only (rs = 0.55, p = 0.03), and superficial SAT to Interleukin-1 receptor antagonist (IL-1RA) in Norwegians only (rs = 0.47, p = 0.04). In conclusion, despite similar adipose tissue distribution in the two groups Pakistanis were more insulin resistant, with a negative correlation of VAT to insulin sensitivity, not present in Norwegians. The correlation of adipose tissue to Leptin, CRP and IL-1RA showed ethnic differences. PMID:25223599

Wium, Cecilie; Eggesbø, Heidi B; Ueland, Thor; Michelsen, Annika E; Torjesen, Peter A; Aukrust, Pål; Birkeland, Kåre

2014-11-01

297

Patterns of regulatory activity across diverse human cell types predict tissue identity, transcription factor binding, and long-range interactions  

PubMed Central

Regulatory elements recruit transcription factors that modulate gene expression distinctly across cell types, but the relationships among these remains elusive. To address this, we analyzed matched DNase-seq and gene expression data for 112 human samples representing 72 cell types. We first defined more than 1800 clusters of DNase I hypersensitive sites (DHSs) with similar tissue specificity of DNase-seq signal patterns. We then used these to uncover distinct associations between DHSs and promoters, CpG islands, conserved elements, and transcription factor motif enrichment. Motif analysis within clusters identified known and novel motifs in cell-type-specific and ubiquitous regulatory elements and supports a role for AP-1 regulating open chromatin. We developed a classifier that accurately predicts cell-type lineage based on only 43 DHSs and evaluated the tissue of origin for cancer cell types. A similar classifier identified three sex-specific loci on the X chromosome, including the XIST lincRNA locus. By correlating DNase I signal and gene expression, we predicted regulated genes for more than 500K DHSs. Finally, we introduce a web resource to enable researchers to use these results to explore these regulatory patterns and better understand how expression is modulated within and across human cell types. PMID:23482648

Sheffield, Nathan C.; Thurman, Robert E.; Song, Lingyun; Safi, Alexias; Stamatoyannopoulos, John A.; Lenhard, Boris; Crawford, Gregory E.; Furey, Terrence S.

2013-01-01

298

DIRECT INJURY, MYIASIS, FORENSICS Effects of Temperature and Tissue Type on the Development of  

E-print Network

human and animal tissue. Insects found on vertebrate remains may be used to estimate the period to analyze insect ev- idence collected from living people and animals. Con- Ã?rming myiasis, the infestation be used as evidence in cases of suspected neglect or abuse (Anderson and Huitson 2004). Myiasis typically

Tomberlin, Jeff

299

Comparative proteomic analysis of the ATP-sensitive K+ channel complex in different tissue types.  

PubMed

ATP-sensitive K(+) (K(ATP)) channels are expressed ubiquitously, but have diverse roles in various organs and cells. Their diversity can partly be explained by distinct tissue-specific compositions of four copies of the pore-forming inward rectifier potassium channel subunits (Kir6.1 and/or Kir6.2) and four regulatory sulfonylurea receptor subunits (SUR1 and/or SUR2). Channel function and/or subcellular localization also can be modified by the proteins with which they transiently or permanently interact to generate even more diversity. We performed a quantitative proteomic analysis of K(ATP) channel complexes in the heart, endothelium, insulin-secreting min6 cells (pancreatic ?-cell like), and the hypothalamus to identify proteins with which they interact in different tissues. Glycolysis is an overrepresented pathway in identified proteins of the heart, min6 cells, and the endothelium. Proteins with other energy metabolic functions were identified in the hypothalamic samples. These data suggest that the metabolo-electrical coupling conferred by K(ATP) channels is conferred partly by proteins with which they interact. A large number of identified cytoskeletal and trafficking proteins suggests endocytic recycling may help control K(ATP) channel surface density and/or subcellular localization. Overall, our data demonstrate that K(ATP) channels in different tissues may assemble with proteins having common functions, but that tissue-specific complex organization also occurs. PMID:23197389

Kefaloyianni, Eirini; Lyssand, John S; Moreno, Cesar; Delaroche, Diane; Hong, Miyoun; Fenyö, David; Mobbs, Charles V; Neubert, Thomas A; Coetzee, William A

2013-01-01

300

Human adipose tissue stromal vascular fraction cells differentiate depending on distinct types of media  

Microsoft Academic Search

Objectives : Angiogenesis, the process of formation of blood vessels, is essential for many physiological as well as pathological processes. It has been shown that human adipose tissue contains a population of non-characterized cells, called stromal-vascular fraction (SVF) cells, which are able to differentiate into several lineages. The aim of this study was to determine conditions for promoting differentiation of

A. Balwierz; U. Czech; A. Polus; R. K. Filipkowski; B. Mioduszewska; T. Proszynski; P. Kolodziejczyk; J. Skrzeczynska-Moncznik; W. Dudek; L. Kaczmarek; J. Kulig; J. Pryjma; A. Dembinska-Kiec

2008-01-01

301

Use of moving aeration membrane bioreactor for the efficient production of tissue type plasminogen activator in serum free medium  

Microsoft Academic Search

A moving aeration-membrane (MAM) bioreactor was employed for the production of 2 ?g\\/mL of tissue type Plasminogen Activator\\u000a (tPA) in serum free medium from normal human fibroblast cells. This system could maintain high cell density for long periods\\u000a of steady state conditions in perfusion cultivation. Under normal operating conditions, shear stress was as low as 0.65 dynes\\/cm2 at the agitation

Hyun Koo Kim; Moon Sun Ham; Jong Soo Hong; Jin Ha Lee; Kyung Yu Park; Hyeon Yong Lee

1996-01-01

302

Component tissues of different morphological types of tomato fruit and their qualitative and quantitative effects on quality of processed product  

E-print Network

fruit were evaluated for surface color, pigment content, pH, sugar con- tent, and titratable acidity. These data were related with the same attributes of tomato juice prepared from the whole fruit. The contribution of the particular tissues... area has the greater titratable acidity. There is a significant, negative correlation between pH and titratable acidity; while a significant, positive correlation exists between 'Brix and titratable acidity of the juice. Of the fruit types evaluated...

Wagner, Alfred Bernhart

2012-06-07

303

Tonic inhibitory effect of cannabinoid receptor 1 (CB1)-mediated signaling on human connective tissue and mucosal type mast cell  

E-print Network

connective tissue and mucosal type mast cell functions in situ via endocannabinoids Koji Sugawara1,4, Tamás 2 3 ** ** NumberofKit+cells pervisualfield control AEA AM251 AEA+AM251 0 1 2 3 *** *** *** NumberofKit+cells pervisualfield control AM251 0.0 0.2 0.4 N.S. NumberofKit/Ki67double+cells pervisualfield control AM251 AM251

Groppe, Jinghua

304

Tissue Doppler imaging for the detection and quantitation of myocardial dysfunction in patients with type 2 diabetes mellitus  

Microsoft Academic Search

The prevalence of type 2 diabetes mellitus is rapidly increasing. Myocardial dysfunction may be a consequence of diabetic cardiomyopathy and it contributes to the poor prognosis of diabetic patients.Aims This study was designed to test whether tissue Doppler imaging might be a suitable tool for early detection of myocardial dysfunction in diabetic patients.Methods Forty-three diabetic patients and 33 non-diabetic controls,

Helene Von Bibra; Inga S Thrainsdottir; Alexander Hansen; Vasilios Dounis; Klas Malmberg; Lars Rydén

2005-01-01

305

Vampire Bat Salivary Plasminogen Activator (Desmoteplase) Inhibits Tissue-Type Plasminogen Activator-Induced Potentiation of Excitotoxic Injury  

Microsoft Academic Search

Background and Purpose—In contrast to tissue-type plasminogen activator (tPA), vampire bat (Desmodus rotundus) salivary plasminogen activator (desmoteplase (DSPA)) does not promote excitotoxic injury when injected directly into the brain. We have compared the excitotoxic effects of intravenously delivered tPA and DSPA and determined whether DSPA can antagonize the neurotoxic and calcium enhancing effects of tPA. Methods—The brain striatal region of

Courtney Reddrop; Randal X. Moldrich; Philip M. Beart; Mark Farso; Gabriel T. Liberatore; David W. Howells; Karl-Uwe Petersen; Wolf-Dieter Schleuning; Robert L. Medcalf

2010-01-01

306

Association between Tissue Characteristics of Coronary Plaque and Distal Embolization after Coronary Intervention in Acute Coronary Syndrome Patients: Insights from a Meta-Analysis of Virtual Histology-Intravascular Ultrasound Studies  

PubMed Central

Background and Objectives The predictive value of plaque characteristics assessed by virtual histology-intravascular ultrasound (VH-IVUS) including fibrous tissue (FT), fibrofatty (FF), necrotic core (NC) and dense calcium (DC) in identifying distal embolization after percutaneous coronary intervention (PCI) is still controversial. We performed a systematic review and meta-analysis to summarize the association of pre-PCI plaque composition and post-PCI distal embolization in acute coronary syndrome patients. Methods Studies were identified in PubMed, OVID, EMBASE, the Cochrane Library, the Current Controlled Trials Register, reviews, and reference lists of relevant articles. A meta-analysis using both fixed and random effects models with assessment of study heterogeneity and publication bias was performed. Results Of the 388 articles screened, 10 studies with a total of 872 subjects (199 with distal embolization and 673 with normal flow) met the eligibility of our study. Compared with normal flow groups, significant higher absolute volume of NC [weighted mean differences (WMD): 5.79 mm3, 95% CI: 3.02 to 8.55 mm3; p<0.001] and DC (WMD: 2.55 mm3, 95% CI: 0.22 to 4.88 mm3; p?=?0.03) were found in acute coronary syndrome patients with distal embolization. Further subgroup analysis demonstrated that the predictive value of tissue characteristics in determining distal embolization was correlated to clinical scenario of the patients, definition of distal embolization, and whether the percutaneous aspiration thrombectomy was applied. Conclusion Our study that pooled current evidence showed that plaque components were closely related to the distal embolization after PCI, especially the absolute volume of NC and DC, supporting further studies with larger sample size and high-methodological quality. PMID:25375841

Yang, Fan; Kong, Lingcong; Zhao, Yichao; Gao, Lingchen; Wang, Wei; Xu, Rende; Ge, Heng; Jiang, Meng; Pu, Jun; He, Ben

2014-01-01

307

Ultrasound Annual, 1983  

SciTech Connect

The 1983 edition of Ultrasound Annual features a state-of-the-art assessment of real-time ultrasound technology and a look at improvements in real-time equipment. Chapters discuss important new obstetric applications of ultrasound in measuring fetal umbilical vein blood flow and monitoring ovarian follicular development in vivo and in vitro fertilization. Other topics covered include transrectal prostate ultrasound using a linear array system; ultrasound of the common bile duct; ultrasound in tropical diseases; prenatal diagnosis of craniospinal anomalies; scrotal ultrasonography; opthalmic ultrasonography; and sonography of the upper abdominal venous system.

Sanders, R.C.; Hill, M.C.

1983-01-01

308

Human immunodeficiency virus type 1 infection of cells and tissues from the upper and lower human female reproductive tract.  

PubMed Central

Viable tissue sections and isolated cell cultures from the human fallopian tube, uterus, cervix, and vaginal mucosa were examined for susceptibility to infection with human immunodeficiency virus type 1 (HIV-1). We examined infectivity by using the monocytotropic strain HIV-1(JR-FL) and several primary isolates of HIV-1 obtained from infected neonates. HIV-1 infection was measured by p24 production in short-term culture and by immunofluorescence detection of HIV-1 Nef and p24 proteins by laser scanning confocal microscopy. Three-color immunofluorescence was used to phenotype HIV-infected cells within tissue sections from each site. Our findings indicate that epithelial, stromal, and dendritic cells and cells with CD14+ CD4+, CD14-CD4-, and CD4+ CD14- phenotypes from the female reproductive tract are infectable with HIV-1. Of importance is the finding that tissues from the upper reproductive tract are susceptible to infection with HIV-1. Moreover, tissue samples from women in all stages of the menstrual cycle, including postmenopausal women (inactive), could be infected with HIV-1. Female reproductive tract cells required a minimum of 60 min of exposure to HIV-1 in order for infection to occur, in contrast to peripheral blood lymphocytes, which became infected after being exposed to HIV-1 for only 1 min. These findings demonstrate that HIV-1 can infect cells and tissues from different sites within the female reproductive tract and suggest that multiple cell types, including epithelial cells, may be targets for the initial infection by HIV-1. PMID:9094621

Howell, A L; Edkins, R D; Rier, S E; Yeaman, G R; Stern, J E; Fanger, M W; Wira, C R

1997-01-01

309

The use of doppler ultrasound to evaluate lesions of localized scleroderma  

Microsoft Academic Search

Doppler ultrasound shows great promise for the evaluation of localized scleroderma (LS). Disease-related structural changes,\\u000a such as tissue thickening, atrophy, and architectural alterations, can be readily detected using ultrasound. High spatial\\u000a resolution enables monitoring of changes in tissue thickness over the course of disease and treatment. Doppler ultrasound\\u000a may also aid assessment of disease activity. Both abnormal tissue echogenicity and

Suzanne C. Li; Melissa S. Liebling

2009-01-01

310

Effects of Tissue-type and Development on Dark Respiration in Two Herbaceous Perennials  

Microsoft Academic Search

Perennial plants go through a number of developmental stages during the growing season. Changes in metabolism during these phases have been documented in laboratory-grown plants but never in native plants growing in natural habitats. The purpose of this study was to describe the seasonal pattern of dark respiration in the above-ground tissues of two herbaceous perennials, Bistorta bistortoides(Pursh) Small and

Cheryl L. McCutchan; Russell K. Monson

2001-01-01

311

Evaluation of response to bovine viral diarrhea virus type 2 vaccination and timing of weaning on yearling ultrasound body composition, performance, and carcass quality traits in Angus calves.  

PubMed

There are concerns about antagonisms between immunity and animal productivity in livestock production. The objective of this study was to evaluate the effect of antibody levels through a response to vaccination protocol, weaning timing, and their interaction on performance and carcass quality traits in Angus beef cattle. Final antibody level and response to vaccination were based on neutralizing serum antibodies against bovine viral diarrhea virus type 2 (BVDV2). Calves were followed through development and the feedlot phase, with collection of yearling ultrasound (n=957), preharvest (n=762), and carcass (n=673) data. In this study, 48% of the animals were observed to have positively responded to the vaccine, as evidenced by higher final antibody levels compared to prevaccination antibody levels. Increased final antibody levels were significantly (P<0.05) associated with increased yearling weight and increased subcutaneous fat over the rump. An interaction between final antibody level and weaning time also was associated (P<0.05) with Warner-Bratzler shear force (WBSF) and meat pH, with a favorable, negative relationship between final antibody and WBSF in calves weaned at initial vaccination. Overall antibody response by wean time interaction had a significant (P<0.05) association with ADG and meat pH, with calves weaned at initial vaccination having a favorable, positive relationship between overall antibody response and ADG. Under both the final antibody and overall antibody response models, animals weaned at initial vaccination had significantly (P<0.05) lower intramuscular fat at yearling time and conversely higher harvest weight than animals weaned at the booster vaccination. When antibody response was grouped (none, low, high), a significant interaction (P<0.05) between antibody response group and weaning time was identified for ADG, harvest weight, and HCW. Animals weaned at the initial vaccination in the high antibody response group had the advantage for ADG, harvest weight, and HCW compared to animals in the high-response group that were weaned at booster vaccination. Linear increases in antibody response generally did not have negative effects on performance or carcass quality traits in finished cattle (P>0.05). Therefore, producers should not be concerned about decreased production or quality attributes as a result of developing a robust antibody response to vaccination for BVDV2 in beef cattle. PMID:24045477

Tait, R G; Downey, E D; Mayes, M S; Park, C A; Ridpath, J F; Garrick, D J; Reecy, J M

2013-11-01

312

Physics of Ultrasound Polytechnic University, Brooklyn, NY 11201  

E-print Network

., Brooklyn 2 Lecture Outline · Ultrasound imaging overview · General characterization of acoustic wave · Wave equation ­ 3D ­ Plane wave ­ Spherical wave · Reflection of wave · Absorption and scattering of wave., Brooklyn 3 Ultrasound Imaging · Measure the reflectivity of tissue to sound waves · Can also measure

Suel, Torsten

313

Predicting Target Displacements Using Ultrasound Elastography and Finite Element Modeling  

Microsoft Academic Search

Soft tissue displacements during minimally invasive surgical procedures may cause target motion and subsequent mis- placement of the surgical tool. A technique is presented to pre- dict target displacements using a combination of ultrasound elas- tography and finite element (FE) modeling. A cubic gelatin\\/agar phantom with stiff targets was manufactured to obtain pre- and post-loading ultrasound radio frequency (RF) data

Jorn op den Buijs; Hendrik H. G. Hansen; Richard G. P. Lopata; Chris L. de Korte; Sarthak Misra

2011-01-01

314

Ultrasound medical image deconvolution using CLEAN L.-T. Chiraa  

E-print Network

Ultrasound medical image deconvolution using CLEAN algorithm L.-T. Chiraa , J.-M. Giraultb , T reconstruction problem of ultrasound medical images using blind deconvolution algorithm has been recognized parameters such as noise or diffusive effects in tissues which produce the speckle noise. We intend

Boyer, Edmond

315

Sonochemistry and Sonoluminescence in Simulated Ultrasound-assisted Lipoplasty Environment  

Microsoft Academic Search

Background: The issue of safety has arisen with the advent of high-intensity ultrasound energy (HIUE) in ultrasound-assisted lipoplasty (UAL). HIUE has been used in the last 3 decades in a variety of surgical procedures, but scientific data are lacking with regard to biologic interactions. We hypothesize that infiltration of tissue with an aqueous solution and exposure to HIUE as practiced

Moris Topaz; Aharon Gedanken; Yuri Koltypin; Menachem Motiei; Matthew B. Grisham; Seth J. Putterman; Keith R. Weninger

1999-01-01

316

Identifying Candidate Genes for Type 2 Diabetes Mellitus and Obesity through Gene Expression Profiling in Multiple Tissues or Cells  

PubMed Central

Type 2 Diabetes Mellitus (T2DM) and obesity have become increasingly prevalent in recent years. Recent studies have focused on identifying causal variations or candidate genes for obesity and T2DM via analysis of expression quantitative trait loci (eQTL) within a single tissue. T2DM and obesity are affected by comprehensive sets of genes in multiple tissues. In the current study, gene expression levels in multiple human tissues from GEO datasets were analyzed, and 21 candidate genes displaying high percentages of differential expression were filtered out. Specifically, DENND1B, LYN, MRPL30, POC1B, PRKCB, RP4-655J12.3, HIBADH, and TMBIM4 were identified from the T2DM-control study, and BCAT1, BMP2K, CSRNP2, MYNN, NCKAP5L, SAP30BP, SLC35B4, SP1, BAP1, GRB14, HSP90AB1, ITGA5, and TOMM5 were identified from the obesity-control study. The majority of these genes are known to be involved in T2DM and obesity. Therefore, analysis of gene expression in various tissues using GEO datasets may be an effective and feasible method to determine novel or causal genes associated with T2DM and obesity. PMID:24455749

Meng, Yuhuan; Zhou, Jinghui; Zhuo, Min; Ling, Fei; Zhang, Yu; Du, Hongli; Wang, Xiaoning

2013-01-01

317

Rayleigh mixture model for plaque characterization in intravascular ultrasound.  

PubMed

Vulnerable plaques are the major cause of carotid and coronary vascular problems, such as heart attack or stroke. A correct modeling of plaque echomorphology and composition can help the identification of such lesions. The Rayleigh distribution is widely used to describe (nearly) homogeneous areas in ultrasound images. Since plaques may contain tissues with heterogeneous regions, more complex distributions depending on multiple parameters are usually needed, such as Rice, K or Nakagami distributions. In such cases, the problem formulation becomes more complex, and the optimization procedure to estimate the plaque echomorphology is more difficult. Here, we propose to model the tissue echomorphology by means of a mixture of Rayleigh distributions, known as the Rayleigh mixture model (RMM). The problem formulation is still simple, but its ability to describe complex textural patterns is very powerful. In this paper, we present a method for the automatic estimation of the RMM mixture parameters by means of the expectation maximization algorithm, which aims at characterizing tissue echomorphology in ultrasound (US). The performance of the proposed model is evaluated with a database of in vitro intravascular US cases. We show that the mixture coefficients and Rayleigh parameters explicitly derived from the mixture model are able to accurately describe different plaque types and to significantly improve the characterization performance of an already existing methodology. PMID:21245004

Seabra, José C; Ciompi, Francesco; Pujol, Oriol; Mauri, Josepa; Radeva, Petia; Sanches, João

2011-05-01

318

Effect of the type of dietary triacylglycerol fatty acids on ?-tocopherol concentration in plasma and tissues of growing pigs.  

PubMed

A study was performed in growing pigs to evaluate the efficacy of ?-tocopherol (Tol) concentration in plasma, muscle, liver, and adipose tissue following dietary supplementation with vitamin E (VE) and various sources of fat. The trial involved 96 piglets weaned at an average of 28 d of age. Piglets were fed for 2 wk a semipurified diet not supplemented with VE. Piglets were then randomly assigned to 5 isoenergetic semipurified diets with 100 IU/kg VE as dl-?-tocopheryl acetate: a control (CTRL) diet (with no added fat) and 4 other diets containing either 3% linseed oil (LIN), 3% hydrogenated coconut oil (COC), 3% olive oil (OLI), or 3% safflower oil (SAF) representing diets rich in n-3 PUFA, SFA, MUFA, and n-6 PUFA, respectively. After 49 d of treatment, pigs were killed and blood, muscle (longissimus dorsi), adipose tissue, and whole liver (without gallbladder) were collected and analyzed for their Tol concentrations. For all tissues, LIN and SAF diets led to lower (P < 0.02) Tol concentrations as compared to the CTRL diet: -63 and -67%, respectively. ?-Tocopherol concentrations in plasma, liver, and adipose tissue were greater (P < 0.001) in the COC group as compared to the CTRL group. The OLI diet led to greater (P < 0.01) liver Tol concentration (+92%) as compared to the CTRL diet but had no significant effect on plasma, muscle, and adipose tissue Tol concentrations. There were significant correlations (P < 0.001) between plasma, muscle, and liver Tol concentrations (r > 0.78). These results show that supplementation with PUFA markedly decreases Tol concentration in blood and tissues of growing pigs, whereas SFA increase Tol content in blood, liver, and adipose tissue. Monounsaturated fatty acids only increase liver Tol concentrations. Therefore, increasing the amount of fat in the diet (from <0.1 to approximately 3.5%) and the type of dietary fatty acids supplemented with VE are key factors with regards to VE concentration in plasma and tissue. The Tol:PUFA needs to be carefully considered to meet the VE pigs requirement and to ensure an optimal Tol meat enrichment. PMID:25349346

Prévéraud, D P; Devillard, E; Rouffineau, F; Borel, P

2014-11-01

319

Medical Ultrasound Imaging.  

ERIC Educational Resources Information Center

Explains the basic principles of ultrasound using everyday physics. Topics include the generation of ultrasound, basic interactions with material, and the measurement of blood flow using the Doppler effect. (Author/MM)

Hughes, Stephen

2001-01-01

320

Ultrasound Research Interface  

Cancer.gov

The ultrasound research interface permits extensive instrument parameter control of a commercially available scanner that allows access to, and export of, the beam-formed signal data while simultaneously displaying the ultrasound system-processed data as a clinical image.

321

The effect of crosstalk in a circular transducer array on ultrasound transmission tomography of breast.  

PubMed

Various types of undesirable crosstalk can occur in ultrasonic arrays consisting of a number of elementary piezoelectric transducers. Crosstalk is a result of deficiency in electrical or mechanical isolation between array elements. It is a function of proximity between piezoelectric transducers of the array or between connections. Small piezoceramic transducers tightly located inside of a circle (cylinder or sphere in 3-D systems) are mostly used for in vivo ultrasound tomography imaging of breast tissue. This means that proper switching of transducers makes it possible to quickly acquire tomographic transmission and reflection data for all directions around the object. A problem with such arrangements is the occurrence of crosstalk, which introduce specific errors to measurement data. Transmission and reflection tomographic images reconstructed based on ultrasonic measurements with crosstalk are distorted in a characteristic way. This work analyzes the effect of crosstalk in a circular transducer array on ultrasound transmission tomography imaging-especially, when used for examination of breast tissue. PMID:25235050

Opielinski, Krzysztof J; Pruchnicki, Piotr; Roguski, Wlodzimierz; Celmer, Mateusz; Gudra, Tadeusz; Majewski, Jaroslaw; Bulkowski, Mariusz; Piotrowski, Tomasz; Wiktorowicz, Andrzej

2014-04-01

322

Elastic registration of 3D ultrasound images.  

PubMed

3D registration of ultrasound images is an important and fast-growing research area with various medical applications, such as image-guided radiotherapy and surgery. However, this registration process is extremely challenging due to the deformation of soft tissue and the existence of speckles in these images. This paper presents a novel intra-modality elastic registration technique for 3D ultrasound images. It uses the general concept of attribute vectors to find the corresponding voxels in the fixed and moving images. The method does not require any pre-segmentation and does not employ any numerical optimization procedure. Therefore, the computational requirements are very low and it has the potential to be used for real-time applications. The technique is implemented and tested for 3D ultrasound images of liver, captured by a 3D ultrasound transducer. The results show that the method is sufficiently accurate and robust and does not easily get trapped with local minima. PMID:16685832

Foroughi, Pezhman; Abolmaesumi, Purang

2005-01-01

323

Nucleic acid delivery with microbubbles and ultrasound.  

PubMed

Nucleic acid-based therapy is a growing field of drug delivery research. Although ultrasound has been suggested to enhance transfection decades ago, it took a combination of ultrasound with nucleic acid carrier systems (microbubbles, liposomes, polyplexes, and viral carriers) to achieve reasonable nucleic acid delivery efficacy. Microbubbles serve as foci for local deposition of ultrasound energy near the target cell, and greatly enhance sonoporation. The major advantage of this approach is in the minimal transfection in the non-insonated non-target tissues. Microbubbles can be simply co-administered with the nucleic acid carrier or can be modified to carry nucleic acid themselves. Liposomes with embedded gas or gas precursor particles can also be used to carry nucleic acid, release and deliver it by the ultrasound trigger. Successful testing in a wide variety of animal models (myocardium, solid tumors, skeletal muscle, and pancreas) proves the potential usefulness of this technique for nucleic acid drug delivery. PMID:24486388

Rychak, Joshua J; Klibanov, Alexander L

2014-06-01

324

Noninvasive Multimodal Evaluation of Bioengineered Cartilage Constructs Combining Time-Resolved Fluorescence and Ultrasound Imaging  

PubMed Central

A multimodal diagnostic system that integrates time-resolved fluorescence spectroscopy, fluorescence lifetime imaging microscopy, and ultrasound backscatter microscopy is evaluated here as a potential tool for assessing changes in engineered tissue composition and microstructure nondestructively and noninvasively. The development of techniques capable of monitoring the quality of engineered tissue, determined by extracellular matrix (ECM) content, before implantation would alleviate the need for destructive assays over multiple time points and advance the widespread development and clinical application of engineered tissues. Using a prototype system combining time-resolved fluorescence spectroscopy, FLIM, and UBM, we measured changes in ECM content occurring during chondrogenic differentiation of equine adipose stem cells on 3D biodegradable matrices. The optical and ultrasound results were validated against those acquired via conventional techniques, including collagen II immunohistochemistry, picrosirius red staining, and measurement of construct stiffness. Current results confirm the ability of this multimodal approach to follow the progression of tissue maturation along the chondrogenic lineage by monitoring ECM production (namely, collagen type II) and by detecting resulting changes in mechanical properties of tissue constructs. Although this study was directed toward monitoring chondrogenic tissue maturation, these data demonstrate the feasibility of this approach for multiple applications toward engineering other tissues, including bone and vascular grafts. PMID:21303258

Fite, Brett Z.; Decaris, Martin; Sun, Yinghua; Sun, Yang; Lam, Adrian; Ho, Clark K.L.

2011-01-01

325

Noninvasive multimodal evaluation of bioengineered cartilage constructs combining time-resolved fluorescence and ultrasound imaging.  

PubMed

A multimodal diagnostic system that integrates time-resolved fluorescence spectroscopy, fluorescence lifetime imaging microscopy, and ultrasound backscatter microscopy is evaluated here as a potential tool for assessing changes in engineered tissue composition and microstructure nondestructively and noninvasively. The development of techniques capable of monitoring the quality of engineered tissue, determined by extracellular matrix (ECM) content, before implantation would alleviate the need for destructive assays over multiple time points and advance the widespread development and clinical application of engineered tissues. Using a prototype system combining time-resolved fluorescence spectroscopy, FLIM, and UBM, we measured changes in ECM content occurring during chondrogenic differentiation of equine adipose stem cells on 3D biodegradable matrices. The optical and ultrasound results were validated against those acquired via conventional techniques, including collagen II immunohistochemistry, picrosirius red staining, and measurement of construct stiffness. Current results confirm the ability of this multimodal approach to follow the progression of tissue maturation along the chondrogenic lineage by monitoring ECM production (namely, collagen type II) and by detecting resulting changes in mechanical properties of tissue constructs. Although this study was directed toward monitoring chondrogenic tissue maturation, these data demonstrate the feasibility of this approach for multiple applications toward engineering other tissues, including bone and vascular grafts. PMID:21303258

Fite, Brett Z; Decaris, Martin; Sun, Yinghua; Sun, Yang; Lam, Adrian; Ho, Clark K L; Leach, J Kent; Marcu, Laura

2011-04-01

326

Evolution and human tissue expression of the Cres/Testatin subgroup genes, a reproductive tissue specific subgroup of the type 2 cystatins.  

PubMed

The cystatin family comprises a group of generally broadly expressed protease inhibitors. The Cres/Testatin subgroup (CTES) genes within the type 2 cystatins differs from the classical type 2 cystatins in having a strikingly reproductive tissue-specific expression, and putative functions in reproduction have therefore been discussed. We have performed evolutionary studies of the CTES genes based on gene searches in genomes from 11 species. Ancestors of the cystatin family can be traced back to plants. We have localized the evolutionary origin of the CTES genes to the split of marsupial and placental mammals. A model for the evolution of these genes illustrates that they constitute a dynamic group of genes, which has undergone several gene expansions and we find indications of a high degree of positive selection, in striking contrast to what is seen for the classical cystatin C. We show with phylogenetic relations that the CTES genes are clustered into three original groups, a testatin, a Cres, and a CstL1 group. We have further characterized the expression patterns of all human members of the subfamily. Of a total of nine identified human genes, four express putative functional transcripts with a predominant expression in the male reproductive system. Our results are compatible with a function of this gene family in reproduction. PMID:20565543

Frygelius, Jessica; Arvestad, Lars; Wedell, Anna; Töhönen, Virpi

2010-01-01

327

A System-Based Approach to Modeling the Ultrasound Signal Backscattered by Red Blood Cells  

Microsoft Academic Search

A system-based model is proposed to describe and simulate the ultrasound signal backscattered by red blood cells (RBCs). The model is that of a space-invariant linear system that takes into consideration important biological tissue stochastic scattering properties as well as the characteristics of the ultrasound system. The formation of the ultrasound signal is described by a convolution integral involving a

Isabelle Fontaine; Michel Bertrand; Guy Cloutier

1999-01-01

328

Role of structural anisotropy of biological tissues in poroelastic wave propagation  

PubMed Central

Ultrasound waves have a broad range of clinical applications as a non-destructive testing approach in imaging and in the diagnoses of medical conditions. Generally, biological tissues are modeled as an homogenized equivalent medium with an apparent density through which a single wave propagates. Only the first wave arriving at the ultrasound probe is used for the measurement of the speed of sound. However, the existence of a second wave in tissues such as cancellous bone has been reported and its existence is an unequivocal signature of Biot type poroelastic media. To account for the fact that ultrasound is sensitive to microarchitecture as well as density, a fabric-dependent anisotropic poroelastic ultrasound (PEU) propagation theory was recently developed. Key to this development was the inclusion of the fabric tensor - a quantitative stereological measure of the degree of structural anisotropy of bone - into the linear poroelasticity theory. In the present study, this framework is extended to the propagation of waves in several soft and hard tissues. It was found that collagen fibers in soft tissues and the mineralized matrix in hard tissues are responsible for the anisotropy of the solid tissue constituent through the fabric tensor in the model. PMID:22162897

Cardoso, Luis; Cowin, Stephen C.

2011-01-01

329

Tissue-specific differences in the development of insulin resistance in a mouse model for type 1 diabetes.  

PubMed

Although insulin resistance is known to underlie type 2 diabetes, its role in the development of type 1 diabetes has been gaining increasing interest. In a model of type 1 diabetes, the nonobese diabetic (NOD) mouse, we found that insulin resistance driven by lipid- and glucose-independent mechanisms is already present in the liver of prediabetic mice. Hepatic insulin resistance is associated with a transient rise in mitochondrial respiration followed by increased production of lipid peroxides and c-Jun N-terminal kinase activity. At the onset of diabetes, increased adipose tissue lipolysis promotes myocellular diacylglycerol accumulation. This is paralleled by increased myocellular protein kinase C ? activity and serum fetuin A levels. Muscle mitochondrial oxidative capacity is unchanged at the onset but decreases at later stages of diabetes. In conclusion, hepatic and muscle insulin resistance manifest at different stages and involve distinct cellular mechanisms during the development of diabetes in the NOD mouse. PMID:24917575

Jelenik, Tomas; Séquaris, Gilles; Kaul, Kirti; Ouwens, D Margriet; Phielix, Esther; Kotzka, Jörg; Knebel, Birgit; Weiß, Jürgen; Reinbeck, Anna Lena; Janke, Linda; Nowotny, Peter; Partke, Hans-Joachim; Zhang, Dongyan; Shulman, Gerald I; Szendroedi, Julia; Roden, Michael

2014-11-01

330

Biological effects of ultrasound  

SciTech Connect

This book contains 14 selections. Some of the titles are: Ultrasonic Bioeffects and Ther Clinical Relevance: An Overview; Investigations into Genetic and Inherited Changes Produced by Ultrasound; Ultrasound and the Mammalian Fetus; Epidemiology and Human Exposure; and Local Hyperthermia by Ultrasound for Cancer Therapy.

Nyborg, W.L.; Ziskin, M.C.

1985-01-01

331

Functional DNA methylation differences between tissues, cell types, and across individuals discovered using the M&M algorithm  

PubMed Central

DNA methylation plays key roles in diverse biological processes such as X chromosome inactivation, transposable element repression, genomic imprinting, and tissue-specific gene expression. Sequencing-based DNA methylation profiling provides an unprecedented opportunity to map and compare complete DNA methylomes. This includes one of the most widely applied technologies for measuring DNA methylation: methylated DNA immunoprecipitation followed by sequencing (MeDIP-seq), coupled with a complementary method, methylation-sensitive restriction enzyme sequencing (MRE-seq). A computational approach that integrates data from these two different but complementary assays and predicts methylation differences between samples has been unavailable. Here, we present a novel integrative statistical framework M&M (for integration of MeDIP-seq and MRE-seq) that dynamically scales, normalizes, and combines MeDIP-seq and MRE-seq data to detect differentially methylated regions. Using sample-matched whole-genome bisulfite sequencing (WGBS) as a gold standard, we demonstrate superior accuracy and reproducibility of M&M compared to existing analytical methods for MeDIP-seq data alone. M&M leverages the complementary nature of MeDIP-seq and MRE-seq data to allow rapid comparative analysis between whole methylomes at a fraction of the cost of WGBS. Comprehensive analysis of nineteen human DNA methylomes with M&M reveals distinct DNA methylation patterns among different tissue types, cell types, and individuals, potentially underscoring divergent epigenetic regulation at different scales of phenotypic diversity. We find that differential DNA methylation at enhancer elements, with concurrent changes in histone modifications and transcription factor binding, is common at the cell, tissue, and individual levels, whereas promoter methylation is more prominent in reinforcing fundamental tissue identities. PMID:23804400

Zhang, Bo; Zhou, Yan; Lin, Nan; Lowdon, Rebecca F.; Hong, Chibo; Nagarajan, Raman P.; Cheng, Jeffrey B.; Li, Daofeng; Stevens, Michael; Lee, Hyung Joo; Xing, Xiaoyun; Zhou, Jia; Sundaram, Vasavi; Elliott, GiNell; Gu, Junchen; Shi, Taoping; Gascard, Philippe; Sigaroudinia, Mahvash; Tlsty, Thea D.; Kadlecek, Theresa; Weiss, Arthur; O'Geen, Henriette; Farnham, Peggy J.; Maire, Cecile L.; Ligon, Keith L.; Madden, Pamela A.F.; Tam, Angela; Moore, Richard; Hirst, Martin; Marra, Marco A.; Zhang, Baoxue; Costello, Joseph F.; Wang, Ting

2013-01-01

332

Contrast enhancement and elastography in endoscopic ultrasound: an overview of clinical applications in pancreatic diseases.  

PubMed

Endoscopic ultrasound is a very accurate imaging technique with a relevant clinical impact in the diagnosis and staging of various conditions such as pancreaticobiliary lesions, esophageal cancer, lung cancer, submucosal lesions and lymph nodes. Despite its increasing importance in everyday clinical routine, endoscopic ultrasound outcomes are still highly operator-dependent and tissue confirmation with fine needle aspiration is very often required for definitive differential diagnosis of tumors. Several techniques of image enhancement have been developed in recent years in the attempt to make the technique less operator-dependent. Among them the most important appear to be contrast harmonic-endoscopic ultrasound and endoscopic ultrasound-elastography. Contrast harmonic-endoscopic ultrasound is performed with a dedicated harmonic which displays the fine vascular network of both normal and pathological tissues after injection of an ultrasound contrast agent. Endoscopic ultrasound-elastography displays with different colors the differences in hardness between tissues, thus estimating elasticity in soft normal tissues which appear red and hard neoplastic tissues which appear blue. While contrast harmonic-endoscopic ultrasound has been introduced into clinical practice, endoscopic ultrasound-elastography mainly represents an investigational tool. The purpose of this paper was to review the mechanism of action and the clinical outcomes of contrast harmonic-endoscopic ultrasound and endoscopic ultrasound-elastography in pancreatic diseases. Both techniques show promising applications in the study of pancreatic tumors including differential diagnosis and providing guidance to fine needle aspiration. PMID:25028864

Serrani, M; Caletti, G; Fusaroli, P

2014-10-01

333

Microbubble-mediated ultrasound therapy: a review of its potential in cancer treatment  

PubMed Central

The inherently toxic nature of chemotherapy drugs is essential for them to kill cancer cells but is also the source of the detrimental side effects experienced by patients. One strategy to reduce these side effects is to limit the healthy tissue exposure by encapsulating the drugs in a vehicle that demonstrates a very low leak rate in circulation while simultaneously having the potential for rapid release once inside the tumor. Designing a vehicle with these two opposing properties is the major challenge in the field of drug delivery. A triggering event is required to change the vehicle from its stable circulating state to its unstable release state. A unique mechanical actuation type trigger is possible by harnessing the size changes that occur when microbubbles interact with ultrasound. These mechanical actuations can burst liposomes and cell membranes alike allowing for rapid drug release and facilitating delivery into nearby cells. The tight focusing ability of the ultrasound to just a few cubic millimeters allows for precise control over the tissue location where the microbubbles destabilize the vehicles. This allows the ultrasound to highlight the tumor tissue and cause rapid drug release from any carrier present. Different vehicle designs have been demonstrated from carrying drug on just the surface of the microbubble itself to encapsulating the microbubble along with the drug within a liposome. In the future, nanoparticles may extend the circulation half-life of these ultrasound triggerable drug-delivery vehicles by acting as nucleation sites of ultrasound-induced mechanical actuation. In addition to the drug delivery capability, the microbubble size changes can also be used to create imaging contrast agents that could allow the internal chemical environment of a tumor to be studied to help improve the diagnosis and detection of cancer. The ability to attain truly tumor-specific release from circulating drug-delivery vehicles is an exciting future prospect to reduce chemotherapy side effects while increasing drug effectiveness. PMID:23667309

Ibsen, Stuart; Schutt, Carolyn E; Esener, Sadik

2013-01-01

334

The Risk of Exposure to Diagnostic Ultrasound in Postnatal Subjects  

PubMed Central

This review evaluates the thermal mechanism for ultrasound-induced biological effects in postnatal subjects. The focus is the evaluation of damage versus temperature increase. A view of ultrasound-induced temperature increase is presented, based on thermodynamic Arrhenius analyses. The hyperthermia and other literature revealed data that allowed for an estimate of a temperature increase threshold of tissue damage for very short exposure times. This evaluation yielded an exposure time extension of the 1997 American Institute of Ultrasound in Medicine Conclusions Regarding Heat statement (American Institute of Ultrasound in Medicine, Laurel, MD) to 0.1 second for nonfetal tissue, where, at this exposure time, the temperature increase threshold of tissue damage was estimated to be about 18°C. The output display standard was also evaluated for soft tissue and bone cases, and it was concluded that the current thermal indices could be improved to reduce the deviations and scatter of computed maximum temperature rises. PMID:18359907

O'Brien, William D.; Deng, Cheri X.; Harris, Gerald R.; Herman, Bruce A.; Merritt, Christopher R.; Sanghvi, Naren; Zachary, James F.

2009-01-01

335

Cavitation methods in therapeutic ultrasound : techniques, mechanisms, and system design  

E-print Network

Focused ultrasound is currently being developed as a non-invasive thermal ablation technique for benign and cancerous tumors in several organ systems. Although these therapies are designed to ablate tissue purely by thermal ...

Sokka, Shunmugavelu D. (Shunmugavelu Doraivelu), 1975-

2004-01-01

336

Markers of Tissue-Specific Insulin Resistance Predict the Worsening of Hyperglycemia, Incident Type 2 Diabetes and Cardiovascular Disease  

PubMed Central

We investigated the ability of surrogate markers of tissue-specific insulin resistance (IR, Matsuda IR, Adipocyte IR, Liver IR) to predict deterioration of hyperglycemia, incident type 2 diabetes and cardiovascular events in the Metabolic Syndrome in Men (METSIM) Study. The METSIM Study includes 10,197 Finnish men, aged 45–73 years, and examined in 2005–2010. A total of 558 of 8,749 non-diabetic participants at baseline were diagnosed with new-onset diabetes and 239 with a new CVD event during a 5.9-year follow-up of this cohort (2010–2013). Compared to fasting plasma insulin level, Matsuda IR (IR in skeletal muscle) and Adipocyte IR were significantly better predictors of 2-hour plasma glucose and glucose area under the curve after adjustment for confounding factors. Liver IR was the strongest predictor of both incident type 2 diabetes (hazard ratio?=?1.83, 95% confidence interval: 1.68–1.98) and cardiovascular events (hazard ratio?=?1.31, 95% confidence interval: 1.15–1.48). Hazard ratios for fasting insulin were 1.37 (95% confidence interval: 1.32–1.42) and 1.11 (95% confidence interval: 1.00–1.24), respectively. Tissue-specific markers of IR, Matsuda IR and Adipocyte IR, were superior to fasting plasma insulin level in predicting worsening of hyperglycemia, and Liver IR was superior to fasting insulin level in predicting incident type 2 diabetes and cardiovascular events. PMID:25310839

FizeI'ova, Maria; Cederberg, Henna; Stancakova, Alena; Jauhiainen, Raimo; Vangipurapu, Jagadish; Kuusisto, Johanna; Laakso, Markku

2014-01-01

337

Tissue engineering: chondrocyte culture on type 1 collagen support. Cytohistological and immunohistochemical study.  

PubMed

The scope of our study is to evaluate the possibility of cultivating and expanding human chondrocytes and seeding them on pure equine type I collagen support. Our results show that human articular cartilaginous cells can multiply and grow on type I collagen substrate with production of extracellular matrix. This type of chondrocyte culture on a support can be used for repairing cartilaginous lesions since they show a correct morphology (evaluated by cytological and histological methods) and a suitable differentiation and phenotype as shown by Alcian PAS staining to indicate the presence of mucopolysaccharides, and immunohistochemical methods to identify collagen II. We believe that these chondrocyte cultures on this biomaterial can be used for repairing cartilaginous lesions with improvement of surgical technique; the support allows adhesion of the chondrocytes to the cartilaginous lesion and a mallebility that favours optimum spatial adaptation. PMID:18038405

Negri, Stefano; Fila, Chiara; Farinato, Sara; Bellomi, Alberto; Pagliaro, Pasquale Paolo

2007-01-01

338

Ultrasound mediated nanoparticle drug delivery  

NASA Astrophysics Data System (ADS)

Ultrasound is not only a powerful diagnostic tool, but also a promising therapeutic technology that can be used to improve localized drug delivery. Microbubble contrast agents are micron sized encapsulated gas filled bubbles that are administered intravenously. Originally developed to enhance ultrasound images, microbubbles are highly echogenic due to the gas core that provides a detectable impedance difference from the surrounding medium. The core also allows for controlled response of the microbubbles to ultrasound pulses. Microbubbles can be pushed using acoustic radiation force and ruptured using high pressures. Destruction of microbubbles can increase permeability at the cellular and vascular level, which can be advantageous for drug delivery. Advances in drug delivery methods have been seen with the introduction of nanoparticles, nanometer sized objects often carrying a drug payload. In chemotherapy, nanoparticles can deliver drugs to tumors while limiting systemic exposure due to abnormalities in tumor vasculature such large gaps between endothelial cells that allow nanoparticles to enter into the interstitial space; this is referred to as the enhanced permeability and retention (EPR) effect. However, this effect may be overestimated in many tumors. Additionally, only a small percentage of the injected dose accumulates in the tumor, which most the nanoparticles accumulating in the liver and spleen. It is hypothesized that combining the acoustic activity of an ultrasound contrast agent with the high payload and extravasation ability of a nanoparticle, localized delivery to the tumor with reduced systemic toxicity can be achieved. This method can be accomplished by either loading nanoparticles onto the shell of the microbubble or through a coadministration method of both nanoparticles and microbubbles. The work presented in this dissertation utilizes novel and commercial nanoparticle formulations, combined with microbubbles and a variety of ultrasound systems. Ultrasound parameters are optimized to achieve maximum cell internalization of molecules and increased nanoparticle delivery to a cell layer on a coverslip. In-vivo studies demonstrate the possibility of using a lower dose of paclitaxel to slow tumor growth rates, increase doxorubicin concentration in tumor tissue, and enhance tumor delivery of fluorescent molecules through treatments that combine nanoparticles with ultrasound and microbubbles.

Mullin, Lee B.

339

Effect of age, impaction types and operative time on inflammatory tissue reactions following lower third molar surgery  

Microsoft Academic Search

Background  Postoperative mobidity following third molar surgery is affected by a number of factors. The study of these factors is essential\\u000a for effective planning and limitation of morbidity. The aim of this study was to determine the effect of age, type of impaction\\u000a and operative time on immediate postoperative tissue reactions following mandibular third molar surgery.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Consecutive patients with impacted mandibular

Seidu A Bello; Wasiu L Adeyemo; Babatunde O Bamgbose; Emeka V Obi; Ademola A Adeyinka

2011-01-01

340

Progression from High Insulin Resistance to Type 2 Diabetes Does Not Entail Additional Visceral Adipose Tissue Inflammation  

PubMed Central

Obesity is associated with a low-grade chronic inflammation state. As a consequence, adipose tissue expresses pro-inflammatory cytokines that propagate inflammatory responses systemically elsewhere, promoting whole-body insulin resistance and consequential islet ?-cell exhaustation. Thus, insulin resistance is considered the early stage of type 2 diabetes. However, there is evidence of obese individuals that never develop diabetes indicating that the mechanisms governing the association between the increase of inflammatory factors and type 2 diabetes are much more complex and deserve further investigation. We studied for the first time the differences in insulin signalling and inflammatory pathways in blood and visceral adipose tissue (VAT) of 20 lean healthy donors and 40 equal morbidly obese (MO) patients classified in high insulin resistance (high IR) degree and diabetes state. We studied the changes in proinflammatory markers and lipid content from serum; macrophage infiltration, mRNA expression of inflammatory cytokines and transcription factors, activation of kinases involved in inflammation and expression of insulin signalling molecules in VAT. VAT comparison of these experimental groups revealed that type 2 diabetic-MO subjects exhibit the same pro-inflammatory profile than the high IR-MO patients, characterized by elevated levels of IL-1?, IL-6, TNF?, JNK1/2, ERK1/2, STAT3 and NF?B. Our work rules out the assumption that the inflammation should be increased in obese people with type 2 diabetes compared to high IR obese. These findings indicate that some mechanisms, other than systemic and VAT inflammation must be involved in the development of type 2 diabetes in obesity. PMID:23110196

Barbarroja, Nuria; Lopez-Pedrera, Chary; Garrido-Sanchez, Lourdes; Mayas, Maria Dolores; Oliva-Olivera, Wilfredo; Bernal-Lopez, Maria Rosa; El Bekay, Rajaa; Tinahones, Francisco Jose

2012-01-01

341

Low-Power 2MHz Pulsed-Wave Transcranial Ultrasound Reduces Ischemic Brain Damage in Rats  

Microsoft Academic Search

It is largely unknown whether prolonged insonation with ultrasound impacts the ischemic brain tissue by itself. Our goal was\\u000a to evaluate safety and the effect of high-frequency ultrasound on infarct volume in rats. Thirty-two Long–Evans rats with\\u000a permanent middle cerebral and carotid artery occlusions received either 2-MHz ultrasound at two levels of insonation power\\u000a (128 or 10 mW) or no ultrasound

Andrei V. Alexandrov; Kristian Barlinn; Roger Strong; Anne W. Alexandrov; Jaroslaw Aronowski

342

Ultrasound as a method for reducing bacteria on poultry  

E-print Network

of the ultrasonic waves (Miller, 1982). The reflections are projected on a screen to give outlines of the different tissue layers. Several investigators have exposed microorganisms to ultrasound as a method of extracting bacterial enzymes, (Stumpf et al. , 1946... of the ultrasonic waves (Miller, 1982). The reflections are projected on a screen to give outlines of the different tissue layers. Several investigators have exposed microorganisms to ultrasound as a method of extracting bacterial enzymes, (Stumpf et al. , 1946...

Feria, Rebeca

2012-06-07

343

The increase in antioxidant capacity after wounding depends on the type of fruit or vegetable tissue  

Microsoft Academic Search

Wounding of fresh produce may elicit an increase in antioxidant capacity associated with wound-induced phenolic compounds. How- ever, there have been no reports on the wounding response of different types of fresh produce. Changes in antioxidant capacity, total soluble phenolics, ascorbic acid, total carotenoids and total anthocyanins were evaluated after wounding in zucchini, white and red cab- bage, iceberg lettuce,

L. Fernando Reyes; J. Emilio Villarreal; Luis Cisneros-Zevallos

344

Persistence of Clostridium botulinum neurotoxin type E in tissues from selected freshwater fish species: implications to public health.  

PubMed

Rainbow trout (Oncorhynchus mykiss), round gobies (Neogobius melanostomas), yellow walleye (Stizostedion vitreum), and yellow perch (Perca flavescens) were given Clostridium botulinum neurotoxin type E (BoNT/E) at four doses (0, 800, 1500, and 4000 mouse lethal doses). BoNT/E was sought in the fish tissues at death or at the conclusion of the experiment (10 days after treatment). Fish were divided into a "fillet" (axial musculature) and a "nonfillet" sample before testing for BoNT/E toxicity with a mouse bioassay. BoNT/E was detected in all species. The percentage of positive BoNT samples ranged across the species and doses from 0 (trout, perch, and walleye) to 17% (round goby) in fillet tissues and from 0 (perch) to 92% (round goby) in nonfillet tissues. The lack of positive fillet samples in three key commercial fish species suggests that the public health implications of eating these fish are minimal. However, the presence of toxin in the nonfillet compartment of a high proportion of fish supports the hypothesis that live intoxicated fish are a vehicle for the transfer of BoNT/E to fish-eating birds, which are then in turn, intoxicated. PMID:16715821

Yule, Adam M; Austin, John W; Barker, Ian K; Cadieux, Brigitte; Moccia, Richard D

2006-05-01

345

NONINVASIVE MEASUREMENT OF LOCAL THERMAL DIFFUSIVITY USING BACKSCATTERED ULTRASOUND AND FOCUSED ULTRASOUND HEATING  

PubMed Central

Previously, noninvasive methods of estimating local tissue thermal and acoustic properties using backscattered ultrasound have been proposed in the literature. In this article, a noninvasive method of estimating local thermal diffusivity in situ during focused ultrasound heating using beamformed acoustic backscatter data and applying novel signal processing techniques is developed. A high intensity focused ultrasound (HIFU) transducer operating at subablative intensities is employed to create a brief local temperature rise of no more than 10°C. Beamformed radio-frequency (RF) data are collected during heating and cooling using a clinical ultrasound scanner. Measurements of the time-varying “acoustic strain”, that is, spatiotemporal variations in the RF echo shifts induced by the temperature related sound speed changes, are related to a solution of the heat transfer equation to estimate the thermal diffusivity in the heated zone. Numerical simulations and experiments performed in vitro in tissue mimicking phantoms and excised turkey breast muscle tissue demonstrate agreement between the ultrasound derived thermal diffusivity estimates and independent estimates made by a traditional hot-wire technique. The new noninvasive ultrasonic method has potential applications in thermal therapy planning and monitoring, physiological monitoring and as a means of noninvasive tissue characterization. PMID:18450361

Anand, Ajay; Kaczkowski, Peter J.

2009-01-01

346

Acoustic Radiation Force Elasticity Imaging in Diagnostic Ultrasound  

PubMed Central

The development of ultrasound-based elasticity imaging methods has been the focus of intense research activity since the mid-1990s. In characterizing the mechanical properties of soft tissues, these techniques image an entirely new subset of tissue properties that cannot be derived with conventional ultrasound techniques. Clinically, tissue elasticity is known to be associated with pathological condition and with the ability to image these features in vivo, elasticity imaging methods may prove to be invaluable tools for the diagnosis and/or monitoring of disease. This review focuses on ultrasound-based elasticity imaging methods that generate an acoustic radiation force to induce tissue displacements. These methods can be performed non-invasively during routine exams to provide either qualitative or quantitative metrics of tissue elasticity. A brief overview of soft tissue mechanics relevant to elasticity imaging is provided, including a derivation of acoustic radiation force, and an overview of the various acoustic radiation force elasticity imaging methods. PMID:23549529

Doherty, Joshua R.; Trahey, Gregg E.; Nightingale, Kathryn R.; Palmeri, Mark L.

2013-01-01

347

Ultrasound backscatter microscope for skin imaging  

Microsoft Academic Search

There is a growing interest in high resolution, subsurface imaging of cutaneous tissues using higher frequency ultrasound. Some of the possible applications of higher frequency skin imaging include tumour staging, boundary definition, and studies of the response of tumours to therapy, investigations of inflammatory skin conditions such as psoriasis and eczema, and basic studies of skin aging, sun damage and

D. H. Turnbull; B. G. Starkoski; K. A. Harasiewiczz; G. R. Lockwood; F. S. Foster

1993-01-01

348

Composite ultrasound imaging apparatus and method  

DOEpatents

An imaging apparatus and method for use in presenting composite two dimensional and three dimensional images from individual ultrasonic frames. A cross-sectional reconstruction is applied by using digital ultrasound frames, transducer orientation and a known center. Motion compensation, rank value filtering, noise suppression and tissue classification are utilized to optimize the composite image.

Morimoto, Alan K. (Albuquerque, NM); Bow, Jr., Wallace J. (Albuquerque, NM); Strong, David Scott (Albuquerque, NM); Dickey, Fred M. (Albuquerque, NM)

1998-01-01

349

Modeling of thermal effects in antivascular ultrasound therapy.  

PubMed

Antivascular ultrasound consisting of low-intensity sonication in the presence of circulating microbubbles of an ultrasound contrast agent has been demonstrated to disrupt blood flow in solid cancers. In this study a mathematical framework is described for the microbubble-induced heating that occurs during antivascular ultrasound. Biological tissues are modeled as a continuum of microbubble-filled vasculature, cells, and interstitial fluids with compressibility equal to the sum of the compressibility of each component. The mathematical simulations show that the absorption of ultrasound waves by viscous damping of the microbubble oscillations induced significant local heating of the tissue vasculature. The extent and the rate of temperature increase not only depends on the properties of the microbubbles and the sonication parameters but is also influenced markedly by the blood flow. Slow flow conditions lead to higher tissue temperatures due to a stronger interaction between microbubbles and ultrasound and reduced heat dissipation. Because tumors have slower blood flow than healthy tissue, the microbubble-induced ultrasound antivascular therapy is likely to affect cancerous tissue more extensively than healthy tissue, providing a way to selectively target the vasculature of cancers. PMID:22280615

Levenback, Benjamin J; Sehgal, Chandra M; Wood, Andrew K W

2012-01-01

350

Validation of Potential Reference Genes for qPCR in Maize across Abiotic Stresses, Hormone Treatments, and Tissue Types  

PubMed Central

The reverse transcription quantitative polymerase chain reaction (RT-qPCR) is a powerful and widely used technique for the measurement of gene expression. Reference genes, which serve as endogenous controls ensure that the results are accurate and reproducible, are vital for data normalization. To bolster the literature on reference gene selection in maize, ten candidate reference genes, including eight traditionally used internal control genes and two potential candidate genes from our microarray datasets, were evaluated for expression level in maize across abiotic stresses (cold, heat, salinity, and PEG), phytohormone treatments (abscisic acid, salicylic acid, jasmonic acid, ethylene, and gibberellins), and different tissue types. Three analytical software packages, geNorm, NormFinder, and Bestkeeper, were used to assess the stability of reference gene expression. The results revealed that elongation factor 1 alpha (EF1?), tubulin beta (?-TUB), cyclophilin (CYP), and eukaryotic initiation factor 4A (EIF4A) were the most reliable reference genes for overall gene expression normalization in maize, while GRP (Glycine-rich RNA-binding protein), GLU1(beta-glucosidase), and UBQ9 (ubiquitin 9) were the least stable and most unsuitable genes. In addition, the suitability of EF1?, ?-TUB, and their combination as reference genes was confirmed by validating the expression of WRKY50 in various samples. The current study indicates the appropriate reference genes for the urgent requirement of gene expression normalization in maize across certain abiotic stresses, hormones, and tissue types. PMID:24810581

Lan, Hai; Gao, Shibin; Liu, Hailan; Liu, Jian; Cao, Moju; Pan, Guangtang; Rong, Tingzhao; Zhang, Suzhi

2014-01-01

351

Adrenal myelolipoma: CT and ultrasound findings  

Microsoft Academic Search

The computed tomographic (CT) and ultrasound (US) appearances of 5 adrenal myelolipomas in 4 patients are reported. The component\\u000a tissues of a myelolipoma determine its CT and US appearance. A myelolipoma consisting primarily of fat has a characteristic\\u000a CT and US appearance. A myelolipoma also containing macroscopic quantities of nonfatty material (blood, calcium, or myeloid\\u000a tissue) may have a nonspecific

C. Whitley Vick; Robert K. Zeman; Eric Mannes; John J. Cronan; James W. Walsh

1984-01-01

352

Left Ventricular Diastolic Dysfunction in Asymptomatic Type 2 Diabetic Patients: Detection and Evaluation by Tissue Doppler Imaging  

PubMed Central

CONFLICT OF INTEREST: NONE DECLARED The aim of the study was detection of diastolic dysfunction of myocardium with Tissue Doppler Imaging (TDI) in asymptomatic type 2 diabetic patients, in five years duration of disease, and normal cardiac function on conventional echocardiography (CE), according to the performance showed on exercise stress test. Material and Methods We studied 300 patients, of them 150 patients with non-obese, normotensive, uncomplicated type 2 diabetes, in five years duration of disease and 150 healthy control subjects. Of all patients, 100 with type 2 diabetes, and 100 patients from the control group underwent exercise test on a treadmill. All participants underwent both CE and TDI echocardiography. With TDI, lateral E’ peak velocity, atrial velocity (A’), their ratio (E’/A’) and systolic velocity (S’) were measured. Diastolic dysfunction was diagnosed by tissue Doppler imaging, and the following criterion was met: E’/A’ ratio <1. Cardiac function with CE was without significant features in the two groups. Results and Discussion Using TDI interrogation, diabetic subjects showed a lower E’ velocity (10,75±1,2 vs. 14±3 cm/s, p<0,001), an increased A’ velocity (10,65±1,8 vs. 11±3 cm/s, p<0,02), and a reduced E/A ratio (0,82±0,04 vs. 1,17±1,4, p<0,001), S (8.92±3,80 vs. 9,30±3.30 cm/sec); E/A (1,17±0.55, p<0,01). In diabetic patients, after the exercise stress test performance, the myocardial velocity increase is registered for wave E’=1,27 cm/sec (12,01%), for wave A’=1,7 cm/sec (15,9%), reduced ratio E’/A’ (0.89±0,1 cm/sec 9,0%) and S’=1,3 cm/sec (14,77%). Whereas, mean myocardial velocity values in examined control group after the exercise stress test were higher as follows: E’=2,7 cm/sec (19%), A’=2,1 cm/sec (14%), E’/A’=0,8 cm/sec (12%), and S’=2,7 cm/sec (18%). Myocardial diastolic dysfunction due to reduced exercise tolerance can be evidenced by TDI in type 2 diabetic subjects, even in the presence of a normal cardiac function with CE and symptom free diabetic patients in rest. Therefore, our findings could justify the use of Tissue Doppler imaging for diastolic function assessment in diabetics with otherwise non significant features on CE. PMID:24039335

Zahiti, Bedri Faik; Gorani, Daut Rashit; Gashi, Fitim Bejtullah; Gjoka, Sami Bajram; Zahiti, Lorita Bedri; Haxhiu, Bekim Syle; Kamberi, Lulzim Selim

2013-01-01

353

Adaptive Real-Time Closed-Loop Temperature Control for Ultrasound Hyperthermia Using Magnetic Resonance Thermometry  

PubMed Central

Previous researchers have successfully demonstrated the application of temperature feedback control for thermal treatment of disease using MR thermometry. Using the temperature-dependent proton resonance frequency (PRF) shift, ultrasound heating for hyperthermia to a target organ (such as the prostate) can be tightly controlled. However, using fixed gain controllers, the response of the target to ultrasound heating varies with type, size, location, shape, stage of growth, and proximity to other vulnerable organs. To adjust for clinical variables, feedback self-tuning regulator (STR) and model reference adaptive control (MRAC) methods have been designed and implemented using real-time, online MR thermometry by adjusting the output power to an ultrasound array to quickly reach the hyperthermia target temperatures. The use of fast adaptive controllers in this application is advantageous because adaptive controllers do not require a priori knowledge of the initial tissue properties and blood perfusion and can quickly reach the steady-state target temperature in the presence of dynamic tissue properties (e.g., thermal conductivity, blood perfusion). This research was conducted to rapidly achieve and manage therapeutic temperatures from an ultrasound array using novel MRI-guided adaptive closed-loop controllers both in ex vivo and in vivo experiments. The ex vivo phantom experiments with bovine muscle (n = 5) show that within 6 ± 0.2 minutes, the tissue temperature increased by 8 ± 1.37°C. Using rabbits’ (n = 5) thigh muscle, the in vivo experiments demonstrated the target temperature reached 44.5°C ± 1.2°C in 8.0 ± 0.5 minutes. The preliminary in vivo experiment with canine prostate hyperthermia achieved 43 ± 2°C in 6.5 ± 0.5 minutes. These results demonstrate that the adaptive controllers with MR thermometry are able to effectively track the target temperature with dynamic tissue properties. PMID:22723751

Sun, L.; Collins, C.M.; Schiano, J.L.; Smith, M.B.; Smith, N.B.

2012-01-01

354

Gene expression of types I and III collagen, decorin, matrix metalloproteinases and tissue inhibitors of metalloproteinases in skin fibroblasts from patients with systemic sclerosis  

Microsoft Academic Search

Cultured fibroblasts from patients with systemic sclerosis (SSc) and normal individuals were examined for gene expression\\u000a of types I and III collagen, decorin, matrix metalloproteinases (MMP) MMP-1, MMP-2, and MMP-3, tissue inhibitors of metalloproteinases\\u000a (TIMP) TIMP-1 and TIMP-2, urokinase- and tissue-type plasminogen activators (u-PA and t-PA). Fibroblasts from patients with\\u000a early stage SSC (less than 1 year duration of disease)

K. Kuroda; H. Shinkai

1997-01-01

355

Multimodal Phantom of Liver Tissue  

PubMed Central

Medical imaging plays an important role in patients' care and is continuously being used in managing health and disease. To obtain the maximum benefit from this rapidly developing technology, further research is needed. Ideally, this research should be done in a patient-safe and environment-friendly manner; for example, on phantoms. The goal of this work was to develop a protocol and manufacture a multimodal liver phantom that is suitable for ultrasound, computed tomography, and magnetic resonance imaging modalities. The proposed phantom consists of three types of mimicked soft tissues: liver parenchyma, tumors, and portal veins, that are made of six ingredients: candle gel, sephadex®, agarose, glycerol, distilled water, and silicone string. The entire procedure is advantageous, since preparation of the phantom is simple, rather cost-effective, and reasonably quick – it takes around 2 days. Besides, most of the phantom's parts can be reused to manufacture a new phantom. Comparison of ultrasound images of real patient's liver and the developed phantom shows that the phantom's liver tissue and its structures are well simulated. PMID:23691165

Chmarra, Magdalena K.; Hansen, Rune; Mårvik, Ronald; Langø, Thomas

2013-01-01

356

Multimodal phantom of liver tissue.  

PubMed

Medical imaging plays an important role in patients' care and is continuously being used in managing health and disease. To obtain the maximum benefit from this rapidly developing technology, further research is needed. Ideally, this research should be done in a patient-safe and environment-friendly manner; for example, on phantoms. The goal of this work was to develop a protocol and manufacture a multimodal liver phantom that is suitable for ultrasound, computed tomography, and magnetic resonance imaging modalities. The proposed phantom consists of three types of mimicked soft tissues: liver parenchyma, tumors, and portal veins, that are made of six ingredients: candle gel, sephadex®, agarose, glycerol, distilled water, and silicone string. The entire procedure is advantageous, since preparation of the phantom is simple, rather cost-effective, and reasonably quick - it takes around 2 days. Besides, most of the phantom's parts can be reused to manufacture a new phantom. Comparison of ultrasound images of real patient's liver and the developed phantom shows that the phantom's liver tissue and its structures are well simulated. PMID:23691165

Chmarra, Magdalena K; Hansen, Rune; Mårvik, Ronald; Langø, Thomas

2013-01-01

357

ORIGINAL CONTRIBUTION Investigation of Soft-Tissue Stiffness Alteration in  

E-print Network

effective than one focused on treating established pressure ulcers (10,11). Current documentation for a quantitative assessment and detection technique for pressure ulcers or deep-tissue injury. An ultrasound Words: Spinal cord injuries; Soft-tissue stiffness; Pressure ulcers; Deep-tissue injury; Ultrasound

Makhsous, Mohsen

358

Microbubbles in Ultrasound-Triggered Drug and Gene Delivery  

PubMed Central

Ultrasound contrast agents, in the form of gas-filled microbubbles, are becoming popular in perfusion monitoring; they are employed as molecular imaging agents. Microbubbles are manufactured from biocompatible materials, they can be injected intravenously, and some are approved for clinical use. Microbubbles can be destroyed by ultrasound irradiation. This destruction phenomenon can be applied to targeted drug delivery and enhancement of drug action. The ultrasonic field can be focused at the target tissues and organs; thus, selectivity of the treatment can be improved, reducing undesirable side effects. Microbubbles enhance ultrasound energy deposition in the tissues and serve as cavitation nuclei, increasing intracellular drug delivery. DNA delivery and successful tissue transfection is observed in the areas of the body where ultrasound is applied after intravascular administration of microbubbles and plasmid DNA. Accelerated blood clot dissolution in the areas of insonation by cooperative action of thrombolytic agents and microbubbles is demonstrated in several clinical trials. PMID:18486268

Hernot, Sophie; Klibanov, Alexander L.

2008-01-01

359

Rock expansion caused by ultrasound  

NASA Astrophysics Data System (ADS)

It has during many years been reported that materials' elastic modulus decrease when exposed to influences like mechanical impacts, ultrasound, magnetic fields, electricity and even humidity. Non-perfect atomic structures like rocks, concrete, or damaged metals exhibit a larger effect. This softening has most often been recorded by wave resonance measurements. The motion towards equilibrium is slow - often taking hours or days, which is why the effect is called Slow Dynamics [1]. The question had been raised, if a material expansion also occurs. 'The most fundamental parameter to consider is the volume expansion predicted to occur when positive hole charge carriers become activated, causing a decrease of the electron density in the O2- sublattice of the rock-forming minerals. This decrease of electron density should affect essentially all physical parameters, including the volume.' [2]. A new type of configuration has measured expansion of a rock subjected to ultrasound. A PZT was used as a pressure sensor while the combined thickness of the rock sample and the PZT sensor was held fixed. The expansion increased the stress in both the rock and the PZT, which gave an out-put voltage from the PZT. Knowing its material properties then made it possible to calculate the rock expansion. The equivalent strain caused by the ultrasound was approximately 3 x 10-5. The temperature was monitored and accounted for during the tests and for the maximum expansion the increase was 0.7 C, which means the expansion is at least to some degree caused by heating of the material by the ultrasound. The fraction of bonds activated by ultrasound was estimated to be around 10-5. References: [1] Guyer, R.A., Johnson, P.A.: Nonlinear Mesoscopic Elasticity: The Complex Behaviour of Rocks, Soils, Concrete. Wiley-VCH 2009 [2] M.M. Freund, F.F. Freund, Manipulating the Toughness of Rocks through Electric Potentials, Final Report CIF 2011 Award NNX11AJ84A, NAS Ames 2012.

Hedberg, C.; Gray, A.

2013-12-01

360

Biphasic Electrical Field Stimulation Aids in Tissue Engineering of Multicell-Type Cardiac Organoids  

PubMed Central

The main objectives of current work were (1) to compare the effects of monophasic or biphasic electrical field stimulation on structure and function of engineered cardiac organoids based on enriched cardiomyocytes (CM) and (2) to determine if electrical field stimulation will enhance electrical excitability of cardiac organoids based on multiple cell types. Organoids resembling cardiac myofibers were cultivated in Matrigel-coated microchannels fabricated of poly(ethylene glycol)-diacrylate. We found that field stimulation using symmetric biphasic square pulses at 2.5?V/cm, 1?Hz, 1?ms (per pulse phase) was an improved stimulation protocol, as compared to no stimulation and stimulation using monophasic square pulses of identical total amplitude and duration (5?V/cm, 1?Hz, 2?ms). This was supported by the highest success rate for synchronous contractions, low excitation threshold, the highest cell density, and the highest expression of Connexin-43 in the biphasic group. Subsequently, enriched CM were seeded on the networks of (1) cardiac fibroblasts (FB), (2) D4T endothelial cells (EC), or (3) a mixture of FB and EC that were precultured for 2 days prior to the addition of enriched CM. Biphasic field stimulation was also effective at improving electrical excitability of these cardiac organoids by improving the three-dimensional organization of the cells, increasing cellular elongation and enhancing Connexin-43 presence. PMID:18783322

Chiu, Loraine L.Y.; Iyer, Rohin K.; King, John-Paul

2011-01-01

361

Biphasic electrical field stimulation aids in tissue engineering of multicell-type cardiac organoids.  

PubMed

The main objectives of current work were (1) to compare the effects of monophasic or biphasic electrical field stimulation on structure and function of engineered cardiac organoids based on enriched cardiomyocytes (CM) and (2) to determine if electrical field stimulation will enhance electrical excitability of cardiac organoids based on multiple cell types. Organoids resembling cardiac myofibers were cultivated in Matrigel-coated microchannels fabricated of poly(ethylene glycol)-diacrylate. We found that field stimulation using symmetric biphasic square pulses at 2.5?V/cm, 1?Hz, 1?ms (per pulse phase) was an improved stimulation protocol, as compared to no stimulation and stimulation using monophasic square pulses of identical total amplitude and duration (5?V/cm, 1?Hz, 2?ms). This was supported by the highest success rate for synchronous contractions, low excitation threshold, the highest cell density, and the highest expression of Connexin-43 in the biphasic group. Subsequently, enriched CM were seeded on the networks of (1) cardiac fibroblasts (FB), (2) D4T endothelial cells (EC), or (3) a mixture of FB and EC that were precultured for 2 days prior to the addition of enriched CM. Biphasic field stimulation was also effective at improving electrical excitability of these cardiac organoids by improving the three-dimensional organization of the cells, increasing cellular elongation and enhancing Connexin-43 presence. PMID:18783322

Chiu, Loraine L Y; Iyer, Rohin K; King, John-Paul; Radisic, Milica

2011-06-01

362

Combination of implantable and transurethral ultrasound applicators for prostate thermal therapy  

Microsoft Academic Search

This preliminary investigation demonstrates that using implantable ultrasound applicators (with energy directed away from the rectum and nontargeted tissue) in combination with a directional transurethral ultrasound applicator have potential to provide controlled thermal coagulation and necrosis of small or large regions within the prostate gland, while sparing thermally sensitive rectal tissue

C. J. Diederich; W. H. Nau; D. Deardorff; L. S. Khalil; P. R. Stauffer; E. C. Burdette

1997-01-01

363

Brown adipose tissue dynamics in wild-type and UCP1-knockout mice: in vivo insights with magnetic resonance.  

PubMed

We used noninvasive magnetic resonance imaging (MRI) and magnetic resonance spectroscopy to compare interscapular brown adipose tissue (iBAT) of wild-type (WT) and uncoupling protein 1 (UCP1)-knockout mice lacking UCP1-mediated nonshivering thermogenesis (NST). Mice were sequentially acclimated to an ambient temperature of 30°C, 18°C, and 5°C. We detected a remodeling of iBAT and a decrease in its lipid content in all mice during cold exposure. Ratios of energy-rich phosphates (ATP/ADP, phosphocreatine/ATP) in iBAT were maintained stable during noradrenergic stimulation of thermogenesis in cold- and warm-adapted mice and no difference between the genotypes was observed. As free fatty acids (FFAs) serve as fuel for thermogenesis and activate UCP1 for uncoupling of oxidative phosphorylation, brown adipose tissue is considered to be a main acceptor and consumer of FFAs. We measured a major loss of FFAs from iBAT during noradrenergic stimulation of thermogenesis. This mobilization of FFAs was observed in iBAT of WT mice as well as in mice lacking UCP1. The high turnover and the release of FFAs from iBAT suggests an enhancement of lipid metabolism, which in itself contributes to the sympathetically activated NST and which is independent from uncoupled respiration mediated by UCP1. Our study demonstrates that MRI, besides its potential for visualizing and quantification of fat tissue, is a valuable tool for monitoring functional in vivo processes like lipid and phosphate metabolism during NST. PMID:24343897

Grimpo, Kirsten; Völker, Maximilian N; Heppe, Eva N; Braun, Steve; Heverhagen, Johannes T; Heldmaier, Gerhard

2014-03-01

364

Fast and Automatic Ultrasound Simulation from CT Images  

PubMed Central

Ultrasound is currently widely used in clinical diagnosis because of its fast and safe imaging principles. As the anatomical structures present in an ultrasound image are not as clear as CT or MRI. Physicians usually need advance clinical knowledge and experience to distinguish diseased tissues. Fast simulation of ultrasound provides a cost-effective way for the training and correlation of ultrasound and the anatomic structures. In this paper, a novel method is proposed for fast simulation of ultrasound from a CT image. A multiscale method is developed to enhance tubular structures so as to simulate the blood flow. The acoustic response of common tissues is generated by weighted integration of adjacent regions on the ultrasound propagation path in the CT image, from which parameters, including attenuation, reflection, scattering, and noise, are estimated simultaneously. The thin-plate spline interpolation method is employed to transform the simulation image between polar and rectangular coordinate systems. The Kaiser window function is utilized to produce integration and radial blurring effects of multiple transducer elements. Experimental results show that the developed method is very fast and effective, allowing realistic ultrasound to be fast generated. Given that the developed method is fully automatic, it can be utilized for ultrasound guided navigation in clinical practice and for training purpose. PMID:24348736

Yang, Jian; Liu, Yue; Wang, Yongtian

2013-01-01

365

Intravascular ultrasound imaging  

SciTech Connect

This book will give vascular surgeons, cardiologists, radiologists, and technologists a complete working knowledge of intravascular ultrasound imaging and the crucial role of this new technology in endovascular diagnosis and therapy. The book reviews the essential principles of vascular pathology and ultrasound imaging and then provides state-of-the-art information on intraluminal ultrasound imaging devices and techniques, including practical guidelines for using catheters, optimizing image quality, and avoiding artifacts. Image interpretation and computerized image reconstruction are also discussed in detail. The first section explains the diagnostic, therapeutic, and experimental applications of intravascular ultrasound, particularly as a adjunct to angioplasty and other current interventional procedures.

Cavaye, D.M.; White, R.A. (UCLA School of Medicine in Los Angeles, CA (United States))

1992-01-01

366

Children's (Pediatric) Abdominal Ultrasound Imaging  

MedlinePLUS

... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

367

Transplantation of insulin-secreting cells differentiated from human adipose tissue-derived stem cells into type 2 diabetes mice.  

PubMed

Currently, there are limited ways to preserve or recover insulin secretory capacity in human pancreas. We evaluated the efficacy of cell therapy using insulin-secreting cells differentiated from human eyelid adipose tissue-derived stem cells (hEAs) into type 2 diabetes mice. After differentiating hEAs into insulin-secreting cells (hEA-ISCs) in vitro, cells were transplanted into a type 2 diabetes mouse model. Serum levels of glucose, insulin and c-peptide were measured, and changes of metabolism and inflammation were assessed in mice that received undifferentiated hEAs (UDC group), differentiated hEA-ISCs (DC group), or sham operation (sham group). Human gene expression and immunohistochemical analysis were done. DC group mice showed improved glucose level, and survival up to 60 days compared to those of UDC and sham group. Significantly increased levels of human insulin and c-peptide were detected in sera of DC mice. RT-PCR and immunohistochemical analysis showed human gene expression and the presence of human cells in kidneys of DC mice. When compared to sham mice, DC mice exhibited lower levels of IL-6, triglyceride and free fatty acids as the control mice. Transplantation of hEA-ISCs lowered blood glucose level in type 2 diabetes mice by increasing circulating insulin level, and ameliorating metabolic parameters including IL-6. PMID:24148246

Nam, Ji Sun; Kang, Hyun Mi; Kim, Jiyoung; Park, Seah; Kim, Haekwon; Ahn, Chul Woo; Park, Jin Oh; Kim, Kyung Rae

2014-01-10

368

Preclinical Characterization of Recombinant Human Tissue Kallikrein-1 as a Novel Treatment for Type 2 Diabetes Mellitus  

PubMed Central

Modulation of the kallikrein-kinin system (KKS) has been shown to have beneficial effects on glucose homeostasis and several other physiological responses relevant to the progression of type 2 diabetes mellitus (T2D). The importance of bradykinin and its receptors in mediating these responses is well documented, but the role of tissue kallikrein-1, the protease that generates bradykinin in situ, is much less understood. We developed and tested DM199, recombinant human tissue kallikrein-1 protein (rhKLK-1), as a potential novel therapeutic for T2D. Hyperinsulinemic-euglycemic clamp studies suggest that DM199 increases whole body glucose disposal in non-diabetic rats. Single-dose administration of DM199 in obese db/db mice and ZDF rats, showed an acute, dose-dependent improvement in whole-body glucose utilization. Sub-acute dosing for a week in ZDF rats improved glucose utilization, with a concomitant rise in fasting insulin levels and HOMA1-%B scores. After cessation of sub-acute dosing, fasting blood glucose levels were significantly lower in ZDF rats during a drug wash-out period. Our studies show for the first time that DM199 administration results in acute anti-hyperglycemic effects in several preclinical models, and demonstrate the potential for further development of DM199 as a novel therapeutic for T2D. PMID:25100328

Kolodka, Tadeusz; Charles, Matthew L.; Raghavan, Arvind; Radichev, Ilian A.; Amatya, Christina; Ellefson, Jacob; Savinov, Alexei Y.; Nag, Abhijeet; Williams, Mark S.; Robbins, Mark S.

2014-01-01

369

Expression of VEGF in Periodontal Tissues of Type II Diabetes Mellitus Patients with Chronic Periodontitis -an Immunohistochemical Study  

PubMed Central

Background: Vascular endothelial growth factor (VEGF) induces proliferation of endothelial cells, stimulates angiogenesis, and increases vascular permeability, but information about its role in periodontal diseases is limited. The aim of this study is to determine the association between VEGF expression in healthy and periodontally diseased tissues of healthy and diabetic patients. Materials and Methods: Seventeen systemically healthy and 17 Type 2 diabetic patients (DM), all diagnosed with periodontitis were enrolled into the study. Gingival samples were collected from both periodontal and healthy sites in all patients. Each patient served as his/her own control samples were subjected to immunohistochemical analysis. Results: The diseased sites of diabetic subjects expressed higher level of VEGF when compared to diseased sites of non diabetic subjects with chronic periodontitis, VEGF was observed in healthy periodontal tissues of both diabetic and systemically healthy people with periodontitis and VEGF was intensely present in monocytes and macrophages. Conclusion: The increased expression of VEGF in diseased sites of diabetic patients suggests that diabetes mellitus might have direct influence over VEGF expression. PMID:25302255

Kumar, Senthil

2014-01-01

370

Developmentally Programmed 3? CpG Island Methylation Confers Tissue- and Cell-Type-Specific Transcriptional Activation  

PubMed Central

During development, a small but significant number of CpG islands (CGIs) become methylated. The timing of developmentally programmed CGI methylation and associated mechanisms of transcriptional regulation during cellular differentiation, however, remain poorly characterized. Here, we used genome-wide DNA methylation microarrays to identify epigenetic changes during human embryonic stem cell (hESC) differentiation. We discovered a group of CGIs associated with developmental genes that gain methylation after hESCs differentiate. Conversely, erasure of methylation was observed at the identified CGIs during subsequent reprogramming to induced pluripotent stem cells (iPSCs), further supporting a functional role for the CGI methylation. Both global gene expression profiling and quantitative reverse transcription-PCR (RT-PCR) validation indicated opposing effects of CGI methylation in transcriptional regulation during differentiation, with promoter CGI methylation repressing and 3? CGI methylation activating transcription. By studying diverse human tissues and mouse models, we further confirmed that developmentally programmed 3? CGI methylation confers tissue- and cell-type-specific gene activation in vivo. Importantly, luciferase reporter assays provided evidence that 3? CGI methylation regulates transcriptional activation via a CTCF-dependent enhancer-blocking mechanism. These findings expand the classic view of mammalian CGI methylation as a mechanism for transcriptional silencing and indicate a functional role for 3? CGI methylation in developmental gene regulation. PMID:23459939

Yu, Da-Hai; Ware, Carol; Waterland, Robert A.; Zhang, Jiexin; Chen, Miao-Hsueh; Gadkari, Manasi; Kunde-Ramamoorthy, Govindarajan; Nosavanh, Lagina M.

2013-01-01

371

Ehlers-danlos syndrome, hypermobility type: an underdiagnosed hereditary connective tissue disorder with mucocutaneous, articular, and systemic manifestations.  

PubMed

Ehlers-Danlos syndrome, hypermobility type, constituting a phenotypic continuum with or, perhaps, corresponding to the joint hypermobility syndrome (JHS/EDS-HT), is likely the most common, though the least recognized, heritable connective tissue disorder. Known for decades as a hereditary condition with predominant rheumatologic manifestations, it is now emerging as a multisystemic disorder with widespread manifestations. Nevertheless, the practitioners' awareness of this condition is generally poor and most patients await years or, perhaps, decades before reaching the correct diagnosis. Among the various sites of disease manifestations, skin and mucosae represent a neglected organ where the dermatologist can easily spot diagnostic clues, which consistently integrate joint hypermobility and other orthopedic/neurologic manifestations at physical examination. In this paper, actual knowledge on JHS/EDS-HT is summarized in various sections. Particular attention has been posed on overlooked manifestations, including cutaneous, mucosal, and oropharyngeal features, and early diagnosis techniques, as a major point of interest for the practicing dermatologist. Actual research progresses on JH/EDS-HT envisage an unexpected link between heritable dysfunctions of the connective tissue and a wide range of functional somatic syndromes, most of them commonly diagnosed in the office of various specialists, comprising dermatologists. PMID:23227356

Castori, Marco

2012-01-01

372

A sandwich-type immunosensor using Pd-Pt nanocrystals as labels for sensitive detection of human tissue polypeptide antigen.  

PubMed

A sandwich-type immunosensor was developed for the detection of human tissue polypeptide antigen (hTPA). In this work, a graphene sheet (GS) was synthesized to modify the surface of a glassy carbon electrode (GCE), and Pd-Pt bimetallic nanocrystals were used as secondary-antibody (Ab2) labels for the fabrication of the immunosensor. The amperometric response of the immunosensor for catalyzing hydrogen peroxide (H2O2) was recorded. And electrochemical impedance spectroscopy was used to characterize the fabrication process of the immunosensor. The anti-human tissue polypeptide antigen primary antibody (Ab1) was immobilized onto the GS modified GCE via cross-linking with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide (EDC/NHS). With Ab1 immobilized onto the GS modified GCE and Ab2 linked on Pd-Pt bimetallic nanocrystals, the immunosensor demonstrated a wide linear range (0.0050-15 ng ml(-1)), a low detection limit (1.2 pg ml(-1)), good reproducibility, good selectivity and acceptable stability. This design strategy may provide many potential applications in the detection of other cancer biomarkers. PMID:24406637

Wang, Yaoguang; Wei, Qin; Zhang, Yong; Wu, Dan; Ma, Hongmin; Guo, Aiping; Du, Bin

2014-02-01

373

Localization of bovine papillomavirus type 1 E5 protein to transformed basal keratinocytes and permissive differentiated cells in fibropapilloma tissue.  

PubMed Central

We examined expression of the E5 transforming protein of bovine papillomavirus type 1 (BPV-1) in naturally and experimentally infected bovine cells. Bovine conjunctival fibroblasts transformed in vitro by experimental infection with purified BPV-1 virions expressed significantly higher amounts of the 7-kDa E5 protein than BPV-1-transformed murine C127 cells. Indirect immunofluourescence analysis revealed a cytoplasmic, predominantly juxtanuclear, localization of E5 protein in the in vitro virus-transformed bovine cells. In naturally infected bovine skin fibropapilloma tissue, two widely separated sites of E5 protein synthesis were identified within the epithelial layers. Transformed basal layer keratinocytes throughout the tumor tissue expressed cytoplasmic E5 protein at a low uniform level. In addition, abundant amounts of cytoplasmic E5 protein with a granular staining pattern were detected in highly differentiated keratinocytes in close association with sites of viral capsid protein synthesis. These observations imply roles for the viral E5 oncogene in the growth transformation of basal epidermal keratinocytes as well as in the differentiation-linked process of viral maturation. Detection of a papillomavirus protein in the basal cell population of warts lends support to the hypothesis that these cells are maintained in a transformed state by continuous expression of a viral transforming gene. Images PMID:1319069

Burnett, S; Jareborg, N; DiMaio, D

1992-01-01

374

n-3 Polyunsaturated fatty acids modulate metabolism of insulin-sensitive tissues: implication for the prevention of type 2 diabetes.  

PubMed

Obesity is frequently associated with the development of type 2 diabetes which is firstly characterized by a defect in the response of key metabolic tissues to insulin (insulin resistance). The imbalance in fatty composition of the diet, a low-grade inflammatory state have been described to be involved in the initiation or the amplification of the molecular events involved in this process. The concept of a specific nutritional intervention has emerged as a promising tool against metabolic disorders associated with obesity. In this context, many investigations were conducted to evaluate the potential beneficial impacts of n-3 polyunsaturated fatty acids (n-3 PUFA). The aim of the present review was to summarize the current knowledge about the role of docosahexanoic acid (DHA, 22:6n-3) and eicosapentanoic acid (EPA, 20:5n-3) on key metabolic organs. Only studies aiming to understand the mechanism of actions were selected. The analysis of randomized clinical trial about n-3 PUFA was not considered here. The effects of n-3 PUFA were analyzed in the adipose tissue, the liver, skeletal muscle and the pancreas in the context of obesity and lipid oversupply. Furthermore, in line with recent findings about the role of the modulation of gut microbiota in obesity-related disorders, we summarized the recent findings about the possible link between n-3 PUFA and change in microbiota composition. PMID:24371037

Pinel, Alexandre; Morio-Liondore, Béatrice; Capel, Frédéric

2014-06-01

375

Differences in irradiation susceptibility and turnover between mucosal and connective tissue-type mast cells of mice  

SciTech Connect

Although precursors of mast cells are derived from the bone marrow, phenotypes of mast cells are influenced by the tissues in which final differentiation occurs. Connective tissue-type mast cells (CTMC) and mucosal mast cells (MMC) are different in morphological, biochemical, immunological, and functional criteria. The purpose of the present study was to obtain information about the differentiation process of MMC. First, we compared changes in irradiation susceptibility in mice during the differentiation process of CTMC and MMC. The decrease in irradiation susceptibility was remarkable in the CTMC differentiation process, but it was moderate in that of MMC. Some morphologically identifiable CTMC in the peritoneal cavity had proliferative potential and were highly radioresistant, whereas such a radioresistant population of MMC was not detectable in the gastric mucosa. Second, we estimated the turnover of CTMC and MMC by determining the proportion of mast cells that were labeled with continuously administered bromodeoxyuridine. The turnover of MMC was significantly faster than that of CTMC. The absence of the radioresistant mast cell population in the gastric mucosa appeared to be related to the short life span of MMC.

Fukuzumi, T.; Waki, N.; Kanakura, Y.; Nagoshi, J.; Hirota, S.; Yoshikawa, K.; Kitamura, Y. (Osaka Univ. Medical School (Japan))

1990-08-01

376

Autophosphorylation and dephosphorylation of type II cAMP-dependent protein kinase in intact tissue and cells  

SciTech Connect

Monoclonal antibodies were used to quantitate changes in the extent of autophosphorylation of the type II regulatory subunit of cAMP-dependent protein kinase in intact bovine tracheal smooth muscle and rat hepatocytes. The autophosphorylated and dephosphorylated forms of the regulatory subunit (RII) were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and identified by immunoblot analysis. Incubating smooth muscle strips with agents which stimulate cAMP production caused a rapid and reversible dephosphorylation of phospho RII. In contrast, phospho RII levels in rat hepatocytes were unaffected by elevations in cAMP concentration. Insulin was capable of inhibiting cAMP-dependent protein kinase in hepatocytes. Tissue extracts were tested to identify the basis for the lack of RII dephosphorylation in intact hepatocytes. Rat liver extract contained 4 fold less RII and had an 80 fold slower rate of dephosphorylation of endogenous RII compared to bovine smooth muscle extract. The different rates were not observed using purified, /sup 32/P-labelled RII and tissue extracts suggesting the decreased RII dephosphorylation rate in liver was due to a difference in the availability of endogenous RII rather than a difference in measurable phosphatase activity.

Scott, C.W.

1988-01-01

377

Tissue-type plasminogen activator-induced fibrinolysis is enhanced in patients with breast, lung, pancreas and colon cancer.  

PubMed

Although cancer-mediated changes in hemostatic proteins unquestionably promote hypercoagulation, the effects of neoplasia on fibrinolysis in the circulation are less well defined. The goals of the present investigation were to determine if plasma obtained from patients with breast, lung, pancreas and colon cancer was less or more susceptible to lysis by tissue-type plasminogen activator (tPA) compared to plasma obtained from normal individuals. Archived plasma obtained from patients with breast (n?=?18), colon/pancreas (n?=?27) or lung (n?=?19) was compared to normal individual plasma (n?=?30) using a thrombelastographic assay that assessed fibrinolytic vulnerability to exogenously added tPA. Plasma samples were activated with tissue factor/celite, had tPA added, and had data collected until clot lysis occurred. Additional, similar samples had potato carboxypeptidase inhibitor added to assess the role played by thrombin-activatable fibrinolysis inhibitor in cancer-modulated fibrinolysis. Rather than inflicting a hypofibrinolytic state, the three groups of cancers demonstrated increased vulnerability to tPA (e.g. decreased time to lysis, increased speed of lysis, decreased clot lysis time). However, hypercoagulation manifested as increased speed of clot formation and strength compensated for enhanced fibrinolytic vulnerability, resulting in a clot residence time that was not different from normal individual thrombi. In sum, enhanced hypercoagulability associated with cancer was in part diminished by enhanced fibrinolytic vulnerability to tPA. PMID:24674880

Nielsen, Vance G; Matika, Ryan W; Ley, Michele L B; Waer, Amy L; Gharagozloo, Farid; Kim, Samuel; Nfonsam, Valentine N; Ong, Evan S; Jie, Tun; Warneke, James A; Steinbrenner, Evangelina B

2014-04-01

378

Nanobubbles for enhanced ultrasound imaging of tumors  

PubMed Central

The fabrication and initial applications of nanobubbles (NBs) have shown promising results in recent years. A small particle size is a basic requirement for ultrasound contrast-enhanced agents that penetrate tumor blood vessel pores to allow for targeted imaging and therapy. However, the nanoscale size of the particles used has the disadvantage of weakening the imaging ability of clinical diagnostic ultrasound. In this work, we fabricated a lipid NBs contrast-enhanced ultrasound agent and evaluated its passive targeting ability in vivo. The results showed that the NBs were small (436.8 ± 5.7 nm), and in vitro ultrasound imaging suggested that the ultrasonic imaging ability is comparable to that of microbubbles (MBs). In vivo experiments confirmed the ability of NBs to passively target tumor tissues. The NBs remained in the tumor area for a longer period because they exhibited enhanced permeability and retention. Direct evidence was obtained by direct observation of red fluorescence-dyed NBs in tumor tissue using confocal laser scanning microscopy. We have demonstrated the ability to fabricate NBs that can be used for the in vivo contrast-enhanced imaging of tumor tissue and that have potential for drug/gene delivery. PMID:22393289

Yin, Tinghui; Wang, Ping; Zheng, Rongqin; Zheng, Bowen; Cheng, Du; Zhang, Xinling; Shuai, Xintao

2012-01-01

379

Ultrasound in anesthesia: applying scientific principles to clinical practice.  

PubMed

The use of ultrasound as an adjunct to invasive anesthesia procedures is becoming commonplace. The U.S. Agency for Health Care Quality and the United Kingdom National Institute for Clinical Excellence have identified the role of ultrasound in improving patient safety. Numerous studies have demonstrated the benefits of ultrasound, yet there have also been articles inferring it may not offer additional benefits to traditional landmark techniques. The major disadvantage often cited is that success is user-dependent, and using ultrasound is a unique skill that requires training and experience to become proficient. Modern ultrasound systems incorporate 2 sound technologies to provide users with specific information about what is being viewed. Brightness mode imaging and pulsed-wave Doppler can be combined to reduce potential complications associated with central venous access and regional anesthesia. Human tissue is also an important factor in ultrasound imaging. The different densities of soft tissues, bone, fluid, and air all interact with sound, creating distinctive images that can aid and potentially hinder accuracy. Comprehension of basic ultrasound principles and how it is affected by tissue will enable anesthetists to better understand what is being seen and reduce the potential for errors. PMID:20879635

Falyar, Christian R

2010-08-01

380

Tissue-specific regulatory network extractor (TS-REX): a database and software resource for the tissue and cell type-specific investigation of transcription factor-gene networks  

PubMed Central

The prediction of transcription factor binding sites in genomic sequences is in principle very useful to identify upstream regulatory factors. However, when applying this concept to genomes of multicellular organisms such as mammals, one has to deal with a large number of false positive predictions since many transcription factor genes are only expressed in specific tissues or cell types. We developed TS-REX, a database/software system that supports the analysis of tissue and cell type-specific transcription factor-gene networks based on expressed sequence tag abundance of transcription factor-encoding genes in UniGene EST libraries. The use of expression levels of transcription factor-encoding genes according to hierarchical anatomical classifications covering different tissues and cell types makes it possible to filter out irrelevant binding site predictions and to identify candidates of potential functional importance for further experimental testing. TS-REX covers ESTs from H. sapiens and M. musculus, and allows the characterization of both presence and specificity of transcription factors in user-specified tissues or cell types. The software allows users to interactively visualize transcription factor-gene networks, as well as to export data for further processing. TS-REX was applied to predict regulators of Polycomb group genes in six human tumor tissues and in human embryonic stem cells. PMID:19443447

Colecchia, Federico; Kottwitz, Denise; Wagner, Mandy; Pfenninger, Cosima V.; Thiel, Gerald; Tamm, Ingo; Peterson, Carsten; Nuber, Ulrike A.

2009-01-01

381

Role of duplex ultrasound in the diagnosis and assessment of carotid body tumour: A literature review  

PubMed Central

Summary Carotid body tumour is a rare disease, a slow growing highly vascular tumour of the carotid body tissue and the most common type of the paraganglioma. This article reviews the pathological, clinical and ultrasound features of carotid body tumours and discusses the role of duplex ultrasound in the diagnosis and assessment of this condition. The initial presentation of carotid body tumour is usually a painless palpable neck mass. Some patients may experience local pressure symptoms as well as symptoms from vagal, hypoglossal and cervical sympathetic nerve impingement. Percutaneous needle aspiration or incisional biopsy is contraindicated for the diagnosis of carotid body tumours. Duplex ultrasound, computed tomography scan, magnetic resonance scan and angiography are commonly used diagnostic tools for this condition. Complete surgical excision of carotid body tumour is the treatment of choice as radiation therapy and chemotherapy are unsatisfactory. Based on vascularity and location, duplex ultrasound scan is able to diagnose carotid body tumour and differentiate it from many other masses in the neck. This non-invasive, inexpensive and readily available diagnostic tool can be used as a first-line imaging modality for the diagnosis and assessment of carotid body tumours.

Tong, Yisha

2012-01-01

382

Detecting tissue-specific early warning signals for complex diseases based on dynamical network biomarkers: study of type 2 diabetes by cross-tissue analysis.  

PubMed

Identifying early warning signals of critical transitions during disease progression is a key to achieving early diagnosis of complex diseases. By exploiting rich information of high-throughput data, a novel model-free method has been developed to detect early warning signals of diseases. Its theoretical foundation is based on dynamical network biomarker (DNB), which is also called as the driver (or leading) network of the disease because components or molecules in DNB actually drive the whole system from one state (e.g. normal state) to another (e.g. disease state). In this article, we first reviewed the concept and main results of DNB theory, and then applied the new method to the analysis of type 2 diabetes mellitus (T2DM). Specifically, based on the temporal-spatial gene expression data of T2DM, we identified tissue-specific DNBs corresponding to the critical transitions occurring in liver, adipose and muscle during T2DM development and progression. Actually, we found that there are two different critical states during T2DM development characterized as responses to insulin resistance and serious inflammation, respectively. Interestingly, a new T2DM-associated function, i.e. steroid hormone biosynthesis, was discovered, and those related genes were significantly dysregulated in liver and adipose at the first critical transition during T2DM deterioration. Moreover, the dysfunction of genes related to responding hormone was also detected in muscle at the similar period. Based on the functional and network analysis on pathogenic molecular mechanism of T2DM, we showed that most of DNB genes, in particular the core ones, tended to be located at the upstream of biological pathways, which implied that DNB genes act as the causal factors rather than the consequence to drive the downstream molecules to change their transcriptional activities. This also validated our theoretical prediction of DNB as the driver network. As shown in this study, DNB can not only signal the emergence of the critical transitions for early diagnosis of diseases, but can also provide the causal network of the transitions for revealing molecular mechanisms of disease initiation and progression at a network level. PMID:23620135

Li, Meiyi; Zeng, Tao; Liu, Rui; Chen, Luonan

2014-03-01

383

Comparison of ultrasound temperature imaging with infrared thermometry during radio frequency ablation  

NASA Astrophysics Data System (ADS)

Radio frequency ablation (RFA) is a widely used alternative modality in the treatment of tumors. During RFA, temperature monitoring is essential to ensure accurate and appropriate thermal dosage. Ultrasound temperature imaging based on the detection of echo time-shift has been demonstrated to have good ability to monitor the temperature distribution. However, no study has proven that the region of ultrasound temperature imaging can correspond well to the practical temperature distribution in the tissue. In this study, we aim to combine ultrasound and infrared systems to clarify the correlation between ultrasound temperature imaging and the practical temperature distribution in a tissue. Five porcine livers (n = 5) were ablated using an RFA system and monitored with an ultrasound system to acquire raw backscattered data for temperature imaging. Meanwhile, an infrared imaging system was used to obtain the practical temperature map of the tissue. The results showed that the temperature distribution detected by ultrasound echo time-shift agreed with those obtained from the infrared image. When the tissue temperature was higher than 45 °C, ultrasound temperature imaging is difficult to describe the behavior of the heat transfer in a homogeneous medium. In this study, we used the experimental setup based on combining ultrasound and infrared systems to confirm the reliability and limitations of ultrasound temperature imaging in RFA monitoring. Such an experimental design may be considered as an indispensable platform for the development and optimization of ultrasound temperature imaging techniques in RFA monitoring.

Geng, Xiaonan; Zhou, Zhuhuang; Li, Qiang; Wu, Shuicai; Wang, Chiao-Yin; Liu, Hao-Li; Chuang, Ching-Cheng; Tsui, Po-Hsiang

2014-04-01

384

Endoscopic ultrasound guided fine needle aspiration and useful ancillary methods  

PubMed Central

The role of endoscopic ultrasound (EUS) in evaluating pancreatic pathology has been well documented from the beginning of its clinical use. High spatial resolution and the close proximity to the evaluated organs within the mediastinum and abdominal cavity allow detection of small focal lesions and precise tissue acquisition from suspected lesions within the reach of this method. Fine needle aspiration (FNA) is considered of additional value to EUS and is performed to obtain tissue diagnosis. Tissue acquisition from suspected lesions for cytological or histological analysis allows, not only the differentiation between malignant and non-malignant lesions, but, in most cases, also the accurate distinction between the various types of malignant lesions. It is well documented that the best results are achieved only if an adequate sample is obtained for further analysis, if the material is processed in an appropriate way, and if adequate ancillary methods are performed. This is a multi-step process and could be quite a challenge in some cases. In this article, we discuss the technical aspects of tissue acquisition by EUS-guided-FNA (EUS-FNA), as well as the role of an on-site cytopathologist, various means of specimen processing, and the selection of the appropriate ancillary method for providing an accurate tissue diagnosis and maximizing the yield of this method. The main goal of this review is to alert endosonographers, not only to the different possibilities of tissue acquisition, namely EUS-FNA, but also to bring to their attention the importance of proper sample processing in the evaluation of various lesions in the gastrointestinal tract and other accessible organs. All aspects of tissue acquisition (needles, suction, use of stylet, complications, etc.) have been well discussed lately. Adequate tissue samples enable comprehensive diagnoses, which answer the main clinical questions, thus enabling targeted therapy. PMID:25339816

Tadic, Mario; Stoos-Veic, Tajana; Kusec, Rajko

2014-01-01

385

Visualizing tissue molecular structure of a black type of canola (Brassica) seed with a thick seed coat after heat-related processing in a chemical way.  

PubMed

Heat-related processing of cereal grains, legume seeds, and oil seeds could be used to improve nutrient availability in ruminants. However, different types of processing may have a different impact on intrinsic structure of tissues. To date, there is little research on structure changes after processing within intact tissues. The synchrotron-based molecular imaging technique enables us to detect inherent structure change on a molecular level. The objective of this study was to visualize tissue of black-type canola (Brassica) seed with a thick seed coat after heat-related processing in a chemical way using the synchrotron imaging technique. The results showed that the chemical images of protein amides were obtained through the imaging technique for the raw, wet, and dry heated black type of canola seed tissues. It seems that different types of processing have a different impact on the protein spectral profile in the black type of canola tissues. Wet heating had a greater impact on the protein ?-helix to ?-sheet ratio than dry heating. Both dry and wet heating resulted in different patterns in amide I, the second derivative, and FSD spectra. However, the exact differences in the tissue images are relatively difficult to be obtained through visual comparison. Future studies should focus on (1) comparing the response and sensitivity of canola seeds to various processing methods between the yellow-type and black-type of canola seeds; (2) developing a sensitive method to compare the image difference between tissues and between treatments; (3) developing a method to link images to nutrient digestion, and (4) revealing how structure changes affect nutrient absorption in humans and animals. PMID:23350902

Yu, Peiqiang

2013-02-20

386

Creation and characterization of an ultrasound and CT phantom for noninvasive ultrasound thermometry calibration.  

PubMed

Ultrasound thermometry provides noninvasive 2-D temperature monitoring, and in this paper, we have investigated the use of computed tomography (CT) radiodensity to characterize tissues to improve the accuracy of ultrasound thermometry. Agarose-based tissue-mimicking phantoms were created with glyceryl trioleate (a fat-mimicking material) concentration of 0%, 10%, 20%, 30%, 40%, and 50%. The speed of sound (SOS) of the phantoms was measured over a temperature range of 22.1-41.1 °C. CT images of the phantoms were acquired by a clinical dedicated breast CT scanner, followed by calculation of the Hounsfield units (HU). The phantom was heated with a therapeutic acoustic pulse (1.54 MHz), while RF data were acquired with a 10-MHz linear-array transducer. Two-dimensional speckle tracking was used to calculate the thermal strain offline. The tissue-dependent thermal strain parameter required for ultrasound thermometry was analyzed and correlated with CT radiodensity, followed by the validation of the temperature prediction. Results showed that the change in SOS with the temperature increase was opposite in sign between the 0%-10% and 20%-50% trioleate phantoms. The inverse of the tissue-dependent thermal strain parameter of the phantoms was correlated with the CT radiodensity (R(2) = 0.99). A blinded ultrasound thermometry study on phantoms with a trioleate range of 5%-35% demonstrated the capability to estimate the tissue-dependent thermal strain parameter and estimate temperature with error less than ~1 °C. In conclusion, CT radiodensity may provide a method for improving ultrasound thermometry in heterogeneous tissues. PMID:24107918

Chun-Yen Lai; Kruse, Dustin E; Ferrara, Katherine W; Caskey, Charles F

2014-02-01

387

Isolation of Mitochondria from Leaf Tissue of Panicum miliaceum, a NAD-Malic Enzyme Type C(4) Plant.  

PubMed

A mechanical isolation procedure was developed to study the respiratory properties of mitochondria from the mesophyll and bundle sheath tissue of Panicum miliaceum, a NAD-malic enzyme C(4) plant. A mesophyll fraction and a bundle sheath fraction were obtained from young leaves by differential mechanical treatment. The purity of both fractions was about 80%, based on analysis of the cross-contamination of ribulose bisphosphate carboxylase activity and phosphoenolpyruvate carboxylase activity.Mitochondria were isolated from the two fractions by differential centrifugation and Percoll density gradient centrifugation. The enrichment of mitochondria relative to chloroplast material was about 75-fold in both preparations.Both types of mitochondria oxidized NADH and succinate with respiratory control. Malate oxidation in mesophyll mitochondria was sensitive to KCN and showed good respiratory control. In bundle sheath mitochondria, malate oxidation was largely insensitive to KCN and showed no respiratory control. The oxidation was strongly inhibited by salicylhydroxamic acid, showing that the alternative oxidase was involved. The bundle sheath mitochondria of this type of C(4) species contribute to C(4) photosynthesis through decarboxylation of malate. Malate oxidation linked to an uncoupled, alternative pathway may allow decarboxylation to proceed without the restraints which might occur via coupled electron flow through the cytochrome chain. PMID:16662792

Gardeström, P; Edwards, G E