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Sample records for tissue temperature tissue

  1. Tissue

    Directory of Open Access Journals (Sweden)

    David Morrissey

    2012-01-01

    Full Text Available Purpose. In vivo gene therapy directed at tissues of mesenchymal origin could potentially augment healing. We aimed to assess the duration and magnitude of transene expression in vivo in mice and ex vivo in human tissues. Methods. Using bioluminescence imaging, plasmid and adenoviral vector-based transgene expression in murine quadriceps in vivo was examined. Temporal control was assessed using a doxycycline-inducible system. An ex vivo model was developed and optimised using murine tissue, and applied in ex vivo human tissue. Results. In vivo plasmid-based transgene expression did not silence in murine muscle, unlike in liver. Although maximum luciferase expression was higher in muscle with adenoviral delivery compared with plasmid, expression reduced over time. The inducible promoter cassette successfully regulated gene expression with maximum levels a factor of 11 greater than baseline. Expression was re-induced to a similar level on a temporal basis. Luciferase expression was readily detected ex vivo in human muscle and tendon. Conclusions. Plasmid constructs resulted in long-term in vivo gene expression in skeletal muscle, in a controllable fashion utilising an inducible promoter in combination with oral agents. Successful plasmid gene transfection in human ex vivo mesenchymal tissue was demonstrated for the first time.

  2. Real-time optoacoustic monitoring of temperature in tissues

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  3. Temperature dependence of postmortem MR quantification for soft tissue discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Zech, Wolf-Dieter; Schwendener, Nicole; Jackowski, Christian [University of Bern, From the Institute of Forensic Medicine, Bern (Switzerland); Persson, Anders; Warntjes, Marcel J. [University of Linkoeping, The Center for Medical Image Science and Visualization (CMIV), Linkoeping (Sweden)

    2015-08-15

    To investigate and correct the temperature dependence of postmortem MR quantification used for soft tissue characterization and differentiation in thoraco-abdominal organs. Thirty-five postmortem short axis cardiac 3-T MR examinations were quantified using a quantification sequence. Liver, spleen, left ventricular myocardium, pectoralis muscle and subcutaneous fat were analysed in cardiac short axis images to obtain mean T1, T2 and PD tissue values. The core body temperature was measured using a rectally inserted thermometer. The tissue-specific quantitative values were related to the body core temperature. Equations to correct for temperature differences were generated. In a 3D plot comprising the combined data of T1, T2 and PD, different organs/tissues could be well differentiated from each other. The quantitative values were influenced by the temperature. T1 in particular exhibited strong temperature dependence. The correction of quantitative values to a temperature of 37 C resulted in better tissue discrimination. Postmortem MR quantification is feasible for soft tissue discrimination and characterization of thoraco-abdominal organs. This provides a base for computer-aided diagnosis and detection of tissue lesions. The temperature dependence of the T1 values challenges postmortem MR quantification. Equations to correct for the temperature dependence are provided. (orig.)

  4. Temperature dependence of postmortem MR quantification for soft tissue discrimination

    International Nuclear Information System (INIS)

    Zech, Wolf-Dieter; Schwendener, Nicole; Jackowski, Christian; Persson, Anders; Warntjes, Marcel J.

    2015-01-01

    To investigate and correct the temperature dependence of postmortem MR quantification used for soft tissue characterization and differentiation in thoraco-abdominal organs. Thirty-five postmortem short axis cardiac 3-T MR examinations were quantified using a quantification sequence. Liver, spleen, left ventricular myocardium, pectoralis muscle and subcutaneous fat were analysed in cardiac short axis images to obtain mean T1, T2 and PD tissue values. The core body temperature was measured using a rectally inserted thermometer. The tissue-specific quantitative values were related to the body core temperature. Equations to correct for temperature differences were generated. In a 3D plot comprising the combined data of T1, T2 and PD, different organs/tissues could be well differentiated from each other. The quantitative values were influenced by the temperature. T1 in particular exhibited strong temperature dependence. The correction of quantitative values to a temperature of 37 C resulted in better tissue discrimination. Postmortem MR quantification is feasible for soft tissue discrimination and characterization of thoraco-abdominal organs. This provides a base for computer-aided diagnosis and detection of tissue lesions. The temperature dependence of the T1 values challenges postmortem MR quantification. Equations to correct for the temperature dependence are provided. (orig.)

  5. Dynamics of tissue shrinkage during ablative temperature exposures

    International Nuclear Information System (INIS)

    Rossmann, Christian; Haemmerich, Dieter; Garrett-Mayer, Elizabeth; Rattay, Frank

    2014-01-01

    There is a lack of studies that examine the dynamics of heat-induced shrinkage of organ tissues. Clinical procedures such as radiofrequency ablation, microwave ablation or high-intensity focused ultrasound, use heat to treat diseases such as cancer and cardiac arrhythmia. When heat is applied to tissues, shrinkage occurs due to protein denaturation, dehydration and contraction of collagen at temperatures greater 50 °C. This is particularly relevant for image-guided procedures such as tumor ablation, where pre- and post-treatment images are compared and any changes in dimensions must be considered to avoid misinterpretations of the treatment outcome. We present data from ex vivo, isothermal shrinkage tests in porcine liver tissue, where axial changes in tissue length were recorded during 15 min of heating to temperatures between 60 and 95 °C. A mathematical model was developed to accurately describe the time and temperature-dependent shrinkage behavior. The shrinkage dynamics had the same characteristics independent of temperature; the estimated relative shrinkage, adjusted for time since death, after 15 min heating to temperatures of 60, 65, 75, 85 and 95 °C, was 12.3, 13.8, 16.6, 19.2 and 21.7%, respectively. Our results demonstrate the shrinkage dynamics of organ tissues, and suggest the importance of considering tissue shrinkage for thermal ablative treatments. (paper)

  6. Effect of luminescence transport through adipose tissue on measurement of tissue temperature by using ZnCdS nanothermometers

    Science.gov (United States)

    Volkova, Elena K.; Yanina, Irina Yu.; Sagaydachnaya, Elena; Konyukhova, Julia G.; Kochubey, Vyacheslav I.; Tuchin, Valery V.

    2018-02-01

    The spectra of luminescence of ZnCdS nanoparticles (ZnCdS NPs) were measured and analyzed in a wide temperature range: from room to human body and further to a hyperthermic temperature resulting in tissue morphology change. The results show that the signal of luminescence of ZnCdS NPs placed within the tissue is reasonably good sensitive to temperature change and accompanied by phase transitions of lipid structures of adipose tissue. It is shown that the presence of a phase transition in adipose tissue upon its heating (polymorphic transformations of lipids) leads to a nonmonotonic temperature dependence of the intensity of luminescence for the nanoparticles introduced into adipose tissue. This is due to a change in the light scattering by the tissue. The light scattering of adipose tissue greatly distorts the results of temperature measurements. The application of these nanoparticles is possible for temperature measurements in very thin or weakly scattering samples.

  7. Temperature-monitored optical treatment for radial tissue expansion.

    Science.gov (United States)

    Bak, Jinoh; Kang, Hyun Wook

    2017-07-01

    Esophageal stricture occurs in 7-23% of patients with gastroesophageal reflux disease. However, the current treatments including stent therapy, balloon dilation, and bougienage involve limitations such as stent migration, formation of the new strictures, and snowplow effect. The purpose of the current study was to investigate the feasibility of structural expansion in tubular tissue ex vivo during temperature-monitored photothermal treatment with a diffusing applicator for esophageal stricture. Porcine liver was used as an ex vivo tissue sample for the current study. A glass tube was used to maintain a constant distance between the diffuser and tissue surface and to evaluate any variations in the luminal area after 10-W 1470-nm laser irradiation for potential stricture treatment. The 3D goniometer measurements confirmed roughly isotropic distribution with less than 10% deviation from the average angular intensity over 2π (i.e., 0.86 ± 0.09 in arbitrary unit) from the diffusing applicator. The 30-s irradiation increased the tissue temperature up to 72.5 °C, but due to temperature feedback, the interstitial tissue temperature became saturated at 70 °C (i.e., steady-state error = ±0.4 °C). The irradiation times longer than 5 s presented area expansion index of 1.00 ± 0.04, signifying that irreversible tissue denaturation permanently deformed the lumen in a circular shape and secured the equivalent luminal area to that of the glass tube. Application of a temperature feedback controller for photothermal treatment with the diffusing applicator can regulate the degree of thermal denaturation to feasibly treat esophageal stricture in a tubular tissue.

  8. Effects of tissue susceptibility on brain temperature mapping.

    Science.gov (United States)

    Maudsley, Andrew A; Goryawala, Mohammed Z; Sheriff, Sulaiman

    2017-02-01

    A method for mapping of temperature over a large volume of the brain using volumetric proton MR spectroscopic imaging has been implemented and applied to 150 normal subjects. Magnetic susceptibility-induced frequency shifts in gray- and white-matter regions were measured and included as a correction in the temperature mapping calculation. Additional sources of magnetic susceptibility variations of the individual metabolite resonance frequencies were also observed that reflect the cellular-level organization of the brain metabolites, with the most notable differences being attributed to changes of the N-Acetylaspartate resonance frequency that reflect the intra-axonal distribution and orientation of the white-matter tracts with respect to the applied magnetic field. These metabolite-specific susceptibility effects are also shown to change with age. Results indicate no change of apparent brain temperature with age from 18 to 84 years old, with a trend for increased brain temperature throughout the cerebrum in females relative for males on the order of 0.1°C; slightly increased temperatures in the left hemisphere relative to the right; and a lower temperature of 0.3°C in the cerebellum relative to that of cerebral white-matter. This study presents a novel acquisition method for noninvasive measurement of brain temperature that is of potential value for diagnostic purposes and treatment monitoring, while also demonstrating limitations of the measurement due to the confounding effects of tissue susceptibility variations. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Temperature-controlled radiofrequency ablation of cardiac tissue

    DEFF Research Database (Denmark)

    Petersen, H H; Chen, X; Pietersen, Adrian

    1999-01-01

    BACKGROUND: A variety of basic factors such as electrode tip pressure, flow around the electrode and electrode orientation influence lesion size during radiofrequency ablation, but importantly is dependent on the chosen mode of ablation. However, only little information is available for the frequ......BACKGROUND: A variety of basic factors such as electrode tip pressure, flow around the electrode and electrode orientation influence lesion size during radiofrequency ablation, but importantly is dependent on the chosen mode of ablation. However, only little information is available...... for the frequently used temperature-controlled mode. The purpose of the present experimental study was to evaluate the impact during temperature-controlled radiofrequency ablation of three basic factors regarding electrode-tissue contact and convective cooling on lesion size. METHODS AND RESULTS: In vitro strips......-controlled radiofrequency ablation increased external cooling of the electrode tip due to either flow of the surrounding liquid or poor electrode tissue contact, as exemplified by perpendicular versus parallel electrode orientation, increases lesion size significantly. This is in contrast to the impact of these factors...

  10. Arrhenius temperature dependence of in vitro tissue plasminogen activator thrombolysis

    International Nuclear Information System (INIS)

    Shaw, George J; Dhamija, Ashima; Bavani, Nazli; Wagner, Kenneth R; Holland, Christy K

    2007-01-01

    Stroke is a devastating disease and a leading cause of death and disability. Currently, the only FDA approved therapy for acute ischemic stroke is the intravenous administration of the thrombolytic medication, recombinant tissue plasminogen activator (tPA). However, this treatment has many contraindications and can have dangerous side effects such as intra-cerebral hemorrhage. These treatment limitations have led to much interest in potential adjunctive therapies, such as therapeutic hypothermia (T ≤ 35 deg. C) and ultrasound enhanced thrombolysis. Such interest may lead to combining these therapies with tPA to treat stroke, however little is known about the effects of temperature on the thrombolytic efficacy of tPA. In this work, we measure the temperature dependence of the fractional clot mass loss Δm(T) resulting from tPA exposure in an in vitro human clot model. We find that the temperature dependence is well described by an Arrhenius temperature dependence with an effective activation energy E eff of 42.0 ± 0.9 kJ mole -1 . E eff approximates the activation energy of the plasminogen-to-plasmin reaction of 48.9 kJ mole -1 . A model to explain this temperature dependence is proposed. These results will be useful in predicting the effects of temperature in future lytic therapies

  11. Arrhenius temperature dependence of in vitro tissue plasminogen activator thrombolysis

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, George J [Department of Emergency Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States); Dhamija, Ashima [Department of Emergency Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States); Bavani, Nazli [Department of Emergency Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States); Wagner, Kenneth R [Department of Neurology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States); Holland, Christy K [Department of Biomedical Engineering, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States)

    2007-06-07

    Stroke is a devastating disease and a leading cause of death and disability. Currently, the only FDA approved therapy for acute ischemic stroke is the intravenous administration of the thrombolytic medication, recombinant tissue plasminogen activator (tPA). However, this treatment has many contraindications and can have dangerous side effects such as intra-cerebral hemorrhage. These treatment limitations have led to much interest in potential adjunctive therapies, such as therapeutic hypothermia (T {<=} 35 deg. C) and ultrasound enhanced thrombolysis. Such interest may lead to combining these therapies with tPA to treat stroke, however little is known about the effects of temperature on the thrombolytic efficacy of tPA. In this work, we measure the temperature dependence of the fractional clot mass loss {delta}m(T) resulting from tPA exposure in an in vitro human clot model. We find that the temperature dependence is well described by an Arrhenius temperature dependence with an effective activation energy E{sub eff} of 42.0 {+-} 0.9 kJ mole{sup -1}. E{sub eff} approximates the activation energy of the plasminogen-to-plasmin reaction of 48.9 kJ mole{sup -1}. A model to explain this temperature dependence is proposed. These results will be useful in predicting the effects of temperature in future lytic therapies.

  12. Nd : YAG surgical laser effects in canine prostate tissue: temperature and damage distribution

    NARCIS (Netherlands)

    van Nimwegen, S. A.; L'Eplattenier, H. F.; Rem, A. I.; van der Lugt, J. J.; Kirpensteijn, J.

    2009-01-01

    An in vitro model was used to predict short-term, laser-induced, thermal damage in canine prostate tissue. Canine prostate tissue samples were equipped with thermocouple probes to measure tissue temperature at 3, 6, 9 and 12 mm depths. The tissue surface was irradiated with a Nd:YAG laser in contact

  13. Physiological stress and ethanol accumulation in tree stems and woody tissues at sublethal temperatures from fire

    Science.gov (United States)

    Rick G. Kelsey; Douglas J. Westlind

    2017-01-01

    The lethal temperature limit is 60 degrees Celsius (°C) for plant tissues, including trees, with lower temperatures causing heat stress. As fire injury increases on tree stems, there is an accompanying rise in tissue ethanol concentrations, physiologically linked to impaired mitochondrial oxidative phosphorylation energy production. We theorize that sublethal tissue...

  14. Temperature dependence of acoustic harmonics generated by nonlinear ultrasound beam propagation in ex vivo tissue and tissue-mimicking phantoms.

    Science.gov (United States)

    Maraghechi, Borna; Kolios, Michael C; Tavakkoli, Jahan

    2015-01-01

    Hyperthermia is a cancer treatment technique that could be delivered as a stand-alone modality or in conjunction with chemotherapy or radiation therapy. Noninvasive and real-time temperature monitoring of the heated tissue improves the efficacy and safety of the treatment. A temperature-sensitive acoustic parameter is required for ultrasound-based thermometry. In this paper the amplitude and the energy of the acoustic harmonics of the ultrasound backscattered signal are proposed as suitable parameters for noninvasive ultrasound thermometry. A commercial high frequency ultrasound imaging system was used to generate and detect acoustic harmonics in tissue-mimicking gel phantoms and ex vivo bovine muscle tissues. The pressure amplitude and the energy content of the backscattered fundamental frequency (p1 and E1), the second (p2 and E2) and the third (p3 and E3) harmonics were detected in pulse-echo mode. Temperature was increased from 26° to 46 °C uniformly through both samples. The amplitude and the energy content of the harmonics and their ratio were measured and analysed as a function of temperature. The average p1, p2 and p3 increased by 69%, 100% and 283%, respectively as the temperature was elevated from 26° to 46 °C in tissue samples. In the same experiment the average E1, E2 and E3 increased by 163%, 281% and 2257%, respectively. A similar trend was observed in tissue-mimicking gel phantoms. The findings suggest that the harmonics generated due to nonlinear ultrasound beam propagation are highly sensitive to temperature and could potentially be used for noninvasive ultrasound tissue thermometry.

  15. Temperature dependence of 1H NMR relaxation time, T2, for intact and neoplastic plant tissues

    Science.gov (United States)

    Lewa, Czesław J.; Lewa, Maria

    Temperature dependences of the spin-spin proton relaxation time, T2, have been shown for normal and tumorous tissues collected from kalus culture Nicotiana tabacum and from the plant Kalanchoe daigremontiana. For neoplastic plant tissues, time T2 was increased compared to that for intact plants, a finding similar to that for animal and human tissues. The temperature dependences obtained were compared to analogous relations observed with animal tissues.

  16. Tissue engineering

    CERN Document Server

    Fisher, John P; Bronzino, Joseph D

    2007-01-01

    Increasingly viewed as the future of medicine, the field of tissue engineering is still in its infancy. As evidenced in both the scientific and popular press, there exists considerable excitement surrounding the strategy of regenerative medicine. To achieve its highest potential, a series of technological advances must be made. Putting the numerous breakthroughs made in this field into a broad context, Tissue Engineering disseminates current thinking on the development of engineered tissues. Divided into three sections, the book covers the fundamentals of tissue engineering, enabling technologies, and tissue engineering applications. It examines the properties of stem cells, primary cells, growth factors, and extracellular matrix as well as their impact on the development of tissue engineered devices. Contributions focus on those strategies typically incorporated into tissue engineered devices or utilized in their development, including scaffolds, nanocomposites, bioreactors, drug delivery systems, and gene t...

  17. On the steady state temperature profiles of biological tissues during ...

    African Journals Online (AJOL)

    The Maxwell equations are solved together with the Pennes Bio-heat equation analytically. The procedure of solution is provoked by the solution to the Maxwell equation. The result revealed the effect of the model parameters such as: the thermal conductivity, blood perfusion coefficient, and the thickness of the tissues and ...

  18. Influence trend of temperature distribution in skin tissue generated by different exposure dose pulse laser

    Science.gov (United States)

    Shan, Ning; Wang, Zhijing; Liu, Xia

    2014-11-01

    Laser is widely applied in military and medicine fields because of its excellent capability. In order to effectively defend excess damage by laser, the thermal processing theory of skin tissue generated by laser should be carried out. The heating rate and thermal damage area should be studied. The mathematics model of bio-tissue heat transfer that is irradiated by laser is analyzed. And boundary conditions of bio-tissue are discussed. Three layer FEM grid model of bio-tissue is established. The temperature rising inducing by pulse laser in the tissue is modeled numerically by adopting ANSYS software. The changing trend of temperature in the tissue is imitated and studied under the conditions of different exposure dose pulse laser. The results show that temperature rising in the tissue depends on the parameters of pulse laser largely. In the same conditions, the pulse width of laser is smaller and its instant power is higher. And temperature rising effect in the tissue is very clear. On the contrary, temperature rising effect in the tissue is lower. The cooling time inducing by temperature rising effect in the tissue is longer along with pulse separation of laser is bigger. And the temperature difference is bigger in the pulse period.

  19. Effects of Re-heating Tissue Samples to Core Body Temperature on High-Velocity Ballistic Projectile-tissue Interactions.

    Science.gov (United States)

    Humphrey, Caitlin; Henneberg, Maciej; Wachsberger, Christian; Maiden, Nicholas; Kumaratilake, Jaliya

    2017-11-01

    Damage produced by high-speed projectiles on organic tissue will depend on the physical properties of the tissues. Conditioning organic tissue samples to human core body temperature (37°C) prior to conducting ballistic experiments enables their behavior to closely mimic that of living tissues. To minimize autolytic changes after death, the tissues are refrigerated soon after their removal from the body and re-heated to 37°C prior to testing. This research investigates whether heating 50-mm-cube samples of porcine liver, kidney, and heart to 37°C for varying durations (maximum 7 h) can affect the penetration response of a high-speed, steel sphere projectile. Longer conditioning times for heart and liver resulted in a slight loss of velocity/energy of the projectile, but the reverse effect occurred for the kidney. Possible reasons for these trends include autolytic changes causing softening (heart and liver) and dehydration causing an increase in density (kidney). © 2017 American Academy of Forensic Sciences.

  20. Tissue types (image)

    Science.gov (United States)

    ... are 4 basic types of tissue: connective tissue, epithelial tissue, muscle tissue, and nervous tissue. Connective tissue supports ... binds them together (bone, blood, and lymph tissues). Epithelial tissue provides a covering (skin, the linings of the ...

  1. Tissue Classification

    DEFF Research Database (Denmark)

    Van Leemput, Koen; Puonti, Oula

    2015-01-01

    Computational methods for automatically segmenting magnetic resonance images of the brain have seen tremendous advances in recent years. So-called tissue classification techniques, aimed at extracting the three main brain tissue classes (white matter, gray matter, and cerebrospinal fluid), are now...... well established. In their simplest form, these methods classify voxels independently based on their intensity alone, although much more sophisticated models are typically used in practice. This article aims to give an overview of often-used computational techniques for brain tissue classification...

  2. The study on the effect of low-temperature heat treatment on tissue dehydration fish pond

    Directory of Open Access Journals (Sweden)

    N. S. Rodionova

    2013-01-01

    Full Text Available The paper is studied thermo-moisture treatment of carp on the provisional application of vacuum packaging. The degree of hydration of the carp meat tissues equally depends on the prepackaging, as well as the characteristics of the fluid in the chamber system. With increasing temperature the degree of hydration of meat carp tissue decreases with the reduction of the difference in its numerical values of packed and unpacked samples. Obtained a graph of depence dependence of the speed of carp meat tissue dehydration of the processing temperature. Revealed that the presence of plastic packaging, as well as wetting fluid help reduce the dehydration speed of carp meat tissues.

  3. Temperature distribution in target tumor tissue and photothermal tissue destruction during laser immunotherapy

    Science.gov (United States)

    Doughty, Austin; Hasanjee, Aamr; Pettitt, Alex; Silk, Kegan; Liu, Hong; Chen, Wei R.; Zhou, Feifan

    2016-03-01

    Laser Immunotherapy is a novel cancer treatment modality that has seen much success in treating many different types of cancer, both in animal studies and in clinical trials. The treatment consists of the synergistic interaction between photothermal laser irradiation and the local injection of an immunoadjuvant. As a result of the therapy, the host immune system launches a systemic antitumor response. The photothermal effect induced by the laser irradiation has multiple effects at different temperature elevations which are all required for optimal response. Therefore, determining the temperature distribution in the target tumor during the laser irradiation in laser immunotherapy is crucial to facilitate the treatment of cancers. To investigate the temperature distribution in the target tumor, female Wistar Furth rats were injected with metastatic mammary tumor cells and, upon sufficient tumor growth, underwent laser irradiation and were monitored using thermocouples connected to locally-inserted needle probes and infrared thermography. From the study, we determined that the maximum central tumor temperature was higher for tumors of less volume. Additionally, we determined that the temperature near the edge of the tumor as measured with a thermocouple had a strong correlation with the maximum temperature value in the infrared camera measurement.

  4. Finite element model to study temperature distribution in skin and deep tissues of human limbs.

    Science.gov (United States)

    Agrawal, Mamta; Pardasani, K R

    2016-12-01

    The temperature of body tissues is viewed as an indicator of tissue response in clinical applications since ancient times. The tissue temperature depends on various physical and physiological parameters like blood flow, metabolic heat generation, thermal conductivity of tissues, shape and size of organs etc. In this paper a finite element model has been proposed to study temperature distribution in skin and deep tissues of human limbs. The geometry of human limb is taken as elliptical tapered shape. It is assumed that outer surface of the limb is exposed to the environment. The appropriate boundary conditions have been framed based on physical conditions of the problem. The model has been developed for a three dimensional steady state case. Hexahedral circular sectoral elements are used to discretize the region. The results have been computed to obtain temperature profiles and study the relation of tissue temperature with the parameters like atmospheric temperature, rate of evaporation, thickness of tissues layers and shape of the limb. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Temperature of cutaneous and subcutaneous tissue during the application of aerosols in rats

    Directory of Open Access Journals (Sweden)

    Andre de Oliveira Teixeira

    2014-10-01

    Full Text Available This study compared the thermal changes of cutaneous and subcutaneous tissues exposed to different aerosols. Thirty-six adults Wistar rats were arranged in two treatment groups, one exposed to methyl salicylate (GSM; n = 9 skin and n = 9 subcutaneous and the other exposed to diclofenac diethylammonium (GDD; n = 9 skin and n = 9 subcutaneous aerosols. Five jets were applied for one-second through an apparatus to reduce spray dispersion (3 cmdiameter in the lateral left thigh of the animals. Temperatures were measured every minute (min. during 30 min., with a digital thermometer. In the skin tissue the sensor was positioned manually, in the subcutaneous tissue it was surgically inserted through the rear face and positioned in the lateral thigh. The skin temperature has homogeneously reduced in both groups. In the subcutaneous tissue the GDD has induced hypothermia from the 2nd to 20th min., the lowest temperature was recorded on the 7th min. (-3.6 ± 0.2ºC in relation to basal. Lowering the temperature by GSM took place from the 1st to 21st min, and the lowest temperature occurred on the 1st min (-9.7 ± 0.5ºC in relation to basal. In the three initial minutes the GSM had temperatures 25, 10 and 5% lower than the GDD. Aerosols have induced hypothermia in the tissues, while the GSM has decreased faster and reached lower values of temperature shown in the subcutaneous tissue.

  6. Effect of cold compress application on tissue temperature in healthy dogs.

    Science.gov (United States)

    Millard, Ralph P; Towle-Millard, Heather A; Rankin, David C; Roush, James K

    2013-03-01

    To measure the effect of cold compress application on tissue temperature in healthy dogs. 10 healthy mixed-breed dogs. Dogs were sedated with hydromorphone (0.1 mg/kg, IV) and diazepam (0.25 mg/kg, IV). Three 24-gauge thermocouple needles were inserted to a depth of 0.5 (superficial), 1.0 (middle), and 1.5 (deep) cm into a shaved, lumbar, epaxial region to measure tissue temperature. Cold (-16.8°C) compresses were applied with gravity dependence for periods of 5, 10, and 20 minutes. Tissue temperature was recorded before compress application and at intervals for up to 80 minutes after application. Control data were collected while dogs received identical sedation but with no cold compress. Mean temperature associated with 5 minutes of application at the superficial depth was significantly decreased, compared with control temperatures. Application for 10 and 20 minutes significantly reduced the temperature at all depths, compared with controls and 5 minutes of application. Twenty minutes of application significantly decreased temperature at only the middle depth, compared with 10 minutes of application. With this method of cold treatment, increasing application time from 10 to 20 minutes caused a further significant temperature change at only the middle tissue depth; however, for maximal cooling, the minimum time of application should be 20 minutes. Possible changes in tissue temperature and adverse effects of application > 20 minutes require further evaluation.

  7. Development of tissue bank

    Directory of Open Access Journals (Sweden)

    R P Narayan

    2012-01-01

    Full Text Available The history of tissue banking is as old as the use of skin grafting for resurfacing of burn wounds. Beneficial effects of tissue grafts led to wide spread use of auto and allograft for management of varied clinical conditions like skin wounds, bone defects following trauma or tumor ablation. Availability of adequate amount of tissues at the time of requirement was the biggest challenge that forced clinicians to find out techniques to preserve the living tissue for prolonged period of time for later use and thus the foundation of tissue banking was started in early twentieth century. Harvesting, processing, storage and transportation of human tissues for clinical use is the major activity of tissue banks. Low temperature storage of processed tissue is the best preservation technique at present. Tissue banking organization is a very complex system and needs high technical expertise and skilled personnel for proper functioning in a dedicated facility. A small lapse/deviation from the established protocol leads to loss of precious tissues and or harm to recipients as well as the risk of transmission of deadly diseases and tumors. Strict tissue transplant acts and stringent regulations help to streamline the whole process of tissue banking safe for recipients and to community as whole.

  8. Study of temperature increase and optic depth penetration in photo irradiated human tissues

    International Nuclear Information System (INIS)

    Stolik, Suren; Delgado, Jose A.; Perez, Arllene M.; Anasagasti, Lorenzo

    2009-01-01

    Optical radiation is widely applied in the treatment and diagnosis of different pathologies. If the power density of the incident light is sufficiently high to induce a significant temperature rise in the irradiated tissue, then it is also needed the knowledge of the thermal properties of the tissue for a complete understanding of the therapeutic effects. The thermal penetration depth of several human tissues has been measured applying the diffusion approximation of the radiative transfer equation for the distribution of optical radiation. The method, the experimental setup and the results are presented and discussed. (Author)

  9. Non-invasive tissue temperature measurements based on quantitative diffuse optical spectroscopy (DOS) of water

    Energy Technology Data Exchange (ETDEWEB)

    Chung, S H [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Cerussi, A E; Tromberg, B J [Beckman Laser Institute and Medical Clinic, University of California, Irvine, 1002 Health Sciences Road, Irvine 92612, CA (United States); Merritt, S I [Masimo Corporation, 40 Parker, Irvine, CA 92618 (United States); Ruth, J, E-mail: bjtrombe@uci.ed [Department of Bioengineering, University of Pennsylvania, 210 S. 33rd Street, Room 240, Skirkanich Hall, Philadelphia, PA 19104 (United States)

    2010-07-07

    We describe the development of a non-invasive method for quantitative tissue temperature measurements using Broadband diffuse optical spectroscopy (DOS). Our approach is based on well-characterized opposing shifts in near-infrared (NIR) water absorption spectra that appear with temperature and macromolecular binding state. Unlike conventional reflectance methods, DOS is used to generate scattering-corrected tissue water absorption spectra. This allows us to separate the macromolecular bound water contribution from the thermally induced spectral shift using the temperature isosbestic point at 996 nm. The method was validated in intralipid tissue phantoms by correlating DOS with thermistor measurements (R = 0.96) with a difference of 1.1 {+-} 0.91 {sup 0}C over a range of 28-48 {sup 0}C. Once validated, thermal and hemodynamic (i.e. oxy- and deoxy-hemoglobin concentration) changes were measured simultaneously and continuously in human subjects (forearm) during mild cold stress. DOS-measured arm temperatures were consistent with previously reported invasive deep tissue temperature studies. These results suggest that DOS can be used for non-invasive, co-registered measurements of absolute temperature and hemoglobin parameters in thick tissues, a potentially important approach for optimizing thermal diagnostics and therapeutics.

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

    Science.gov (United States)

    Erez, A; Shitzer, A

    1980-02-01

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

  11. Presence and significance of temperature gradients among different ovarian tissues

    DEFF Research Database (Denmark)

    Hunter, Ronald Henry Fraser; Einer-Jensen, Niels; Greve, Torben

    2006-01-01

    also be involved. Temperature gradients would be maintained locally by counter-current heat exchange mechanisms and, in this context, the microvasculature and lymphatic flow of individual follicles were found to be appropriate. Observations on the temperature of preovulatory follicles appear relevant......, and cow, and generally fell in the range of 1.3-1.7 degrees C: follicles were always cooler than stroma. Measurements were made principally by means of a thermo-sensing camera at midventral laparotomy, but also using microelectrodes or thermistor probes sited in the follicular antrum of rabbits and pigs...

  12. Tissue irradiator

    International Nuclear Information System (INIS)

    Hungate, F.P.; Riemath, W.F.; Bunnell, L.R.

    1975-01-01

    A tissue irradiator is provided for the in-vivo irradiation of body tissue. The irradiator comprises a radiation source material contained and completely encapsulated within vitreous carbon. An embodiment for use as an in-vivo blood irradiator comprises a cylindrical body having an axial bore therethrough. A radioisotope is contained within a first portion of vitreous carbon cylindrically surrounding the axial bore, and a containment portion of vitreous carbon surrounds the radioisotope containing portion, the two portions of vitreous carbon being integrally formed as a single unit. Connecting means are provided at each end of the cylindrical body to permit connections to blood-carrying vessels and to provide for passage of blood through the bore. In a preferred embodiment, the radioisotope is thulium-170 which is present in the irradiator in the form of thulium oxide. A method of producing the preferred blood irradiator is also provided, whereby nonradioactive thulium-169 is dispersed within a polyfurfuryl alcohol resin which is carbonized and fired to form the integral vitreous carbon body and the device is activated by neutron bombardment of the thulium-169 to produce the beta-emitting thulium-170

  13. Evaluating temperature changes of brain tissue due to induced heating of cell phone waves

    Directory of Open Access Journals (Sweden)

    Farhad Forouharmajd

    2018-01-01

    Full Text Available Background: Worries have recently been increased in the absorption of radiofrequency waves and their destructing effects on human health by increasing use of cell phones (mobile phones. This study performed to determine the thermal changes due to mobile phone radio frequency waves in gray and white brain tissue. Methods: This study is an empirical study, where the thermal changes of electromagnetic waves resulted from cell phones (900 MHZ, specific absorption rate for head 1.18 w/kg on the 15 brain tissue of a cow were analyzed in a compartment with three different thickness of 2 mm, 12 mm, and 22 mm, for 15 min. The Lutron thermometer (model: MT-917 with 0.01°C precision was used for measuring the tissue temperature. For each thickness was measured three times. Data analysis is done by Lutron and MATLAB software packages. Results: In confronting of the tissue with the cell phone, the temperature was increased by 0.53°C in the 2 mm thickness that is the gray matter of the brain, increased by 0.99°C in the 12 mm thickness, and also increased by 0.92°C in the 22 mm thickness. Brain temperature showed higher rates than the base temperature after 15 min of confrontation with cell phone waves in all the three thicknesses. Conclusions: Cell phone radiated radio frequency waves were effective on increasing brain tissue temperature, and this temperature increase has cumulative effect on the tissue, being higher, for some time after the confrontation than the time with no confrontation.

  14. Glass transition temperature of dried lens tissue pretreated with trehalose, maltose, or cyclic tetrasaccharide.

    Science.gov (United States)

    Kawata, Tetsuhiro; Matsuo, Toshihiko; Uchida, Tetsuya

    2014-01-01

    Glass transition temperature is a main indicator for amorphous polymers and biological macromolecules as materials, and would be a key for understanding the role of trehalose in protecting proteins and cells against desiccation. In this study, we measured the glass transition temperature by differential scanning calorimetry of dried lens tissues as a model of a whole biological tissue to know the effect of pretreatment by trehalose and other sugars. Isolated porcine lenses were incubated with saline, 100 or 1000 mM concentration of trehalose, maltose, or cyclic tetrasaccharide dissolved in saline at room temperature for 150 minutes. The solutions were removed and all samples were dried at room temperature in a desiccator until no weight change. The dried tissues were ground into powder and placed in a measuring pan for differential scanning calorimetry. The glass transition temperature of the dried lens tissues, as a mean and standard deviation, was 63.0 ± 6.4°C (n = 3) with saline pretreatment; 53.0 ± 0.8°C and 56.3 ± 2.7°C (n = 3), respectively, with 100 and 1000 mM trehalose pretreatment; 56.0 ± 1.6°C and 55.8 ± 1.1°C (n = 3), respectively, with 100 and 1000 mM maltose pretreatment; 60.0 ± 8.8°C and 59.2 ± 6.3°C (n = 3), respectively, with 100 and 1000 mM cyclic tetrasaccharide pretreatment. The glass transition temperature appeared lower, although not significantly, with trehalose and maltose pretreatments than with saline and cyclic tetrasaccharide pretreatments (P > 0.05, Kruskal-Wallis test). The glass transition temperature of the dried lens tissues with trehalose pretreatment appeared more noticeable on the thermogram, compared with other pretreatments. The glass transition temperature was measured for the first time in the dried lens tissues as an example of a whole biological tissue and might provide a basis for tissue preservation in the dried condition.

  15. Effect of warm compress application on tissue temperature in healthy dogs.

    Science.gov (United States)

    Millard, Ralph P; Towle-Millard, Heather A; Rankin, David C; Roush, James K

    2013-03-01

    To measure the effect of warm compress application on tissue temperature in healthy dogs. 10 healthy mixed-breed dogs. Dogs were sedated with hydromorphone (0.1 mg/kg, IV) and diazepam (0.25 mg/kg, IV). Three 24-gauge thermocouple needles were inserted to a depth of 0.5 cm (superficial), 1.0 cm (middle), and 1.5 cm (deep) into a shaved, lumbar, epaxial region to measure tissue temperature. Warm (47°C) compresses were applied with gravity dependence for periods of 5, 10, and 20 minutes. Tissue temperature was recorded before compress application and at intervals for up to 80 minutes after application. Control data were collected while dogs received identical sedation but with no warm compress. Mean temperature associated with 5 minutes of heat application at the superficial, middle, and deep depths was significantly increased, compared with the control temperature. Application for 10 minutes significantly increased the temperature at all depths, compared with 5 minutes of application. Mean temperature associated with 20 minutes of application was not different at the superficial or middle depths, compared with 10 minutes of application. Temperature at the deep depth associated with 10 minutes of application was significantly higher, compared with 20 minutes of application, but all temperature increases at this depth were minimal. Results suggested that application of a warm compress should be performed for 10 minutes. Changes in temperature at a tissue depth of 1.5 cm were minimal or not detected. The optimal compress temperature to achieve therapeutic benefits was not determined.

  16. Temperature distribution analysis of tissue water vaporization during microwave ablation: experiments and simulations.

    Science.gov (United States)

    Ai, Haiming; Wu, Shuicai; Gao, Hongjian; Zhao, Lei; Yang, Chunlan; Zeng, Yi

    2012-01-01

    The temperature distribution in the region near a microwave antenna is a critical factor that affects the entire temperature field during microwave ablation of tissue. It is challenging to predict this distribution precisely, because the temperature in the near-antenna region varies greatly. The effects of water vaporisation and subsequent tissue carbonisation in an ex vivo porcine liver were therefore studied experimentally and in simulations. The enthalpy and high-temperature specific absorption rate (SAR) of liver tissues were calculated and incorporated into the simulation process. The accuracy of predictions for near-field temperatures in our simulations has reached the level where the average maximum error is less than 5°C. In addition, a modified thermal model that accounts for water vaporisation and the change in the SAR distribution pattern is proposed and validated with experiment. The results from this study may be useful in the clinical practice of microwave ablation and can be applied to predict the temperature field in surgical planning.

  17. Improved system for identifying biological tissue temperature using electrical impedance tomography

    Directory of Open Access Journals (Sweden)

    Korolyuk Evgeniy

    2018-01-01

    Full Text Available This paper proposes a cheap and compact medical system that determines the temperature of an object using broadband impedance tomography. This system can be used in medicine to visualize ice structure in tissue during cryosurgical operations, as well as for fault diagnosis and location in studied industrial objects. These effects are achieved by measuring electrical impedance between electrode pairs in the measuring chamber. The assembled prototype is compact, consumes little power, and allows to non-invasively determine the impedance of a target object in real time. The research included experimental studies to determine the dependence of the impedance spectrum of saline water and muscle tissue on temperature in broad band spectrum, which allowed to obtain the dependence of total electrical impedance of target objects on temperature.

  18. Self assembled temperature responsive surfaces for generation of cell patches for bone tissue engineering

    International Nuclear Information System (INIS)

    Valmikinathan, Chandra M; ChangWei; Xu Jiahua; Yu Xiaojun

    2012-01-01

    One of the major challenges in the fabrication of tissue engineered scaffolds is the ability of the scaffold to biologically mimic autograft-like tissues. One of the alternate approaches to achieve this is by the application of cell seeded scaffolds with optimal porosity and mechanical properties. However, the current approaches for seeding cells on scaffolds are not optimal in terms of seeding efficiencies, cell penetration into the scaffold and more importantly uniform distribution of cells on the scaffold. Also, recent developments in scaffold geometries to enhance surface areas, pore sizes and porosities tend to further complicate the scenario. Cell sheet-based approaches for cell seeding have demonstrated a successful approach to generate scaffold-free tissue engineering approaches. However, the method of generating the temperature responsive surface is quite challenging and requires carcinogenic reagents and gamma rays. Therefore, here, we have developed temperature responsive substrates by layer-by-layer self assembly of smart polymers. Multilayer thin films prepared from tannic acid and poly N-isopropylacrylamide were fabricated based on their electrostatic and hydrogen bonding interactions. Cell attachment and proliferation studies on these thin films showed uniform cell attachment on the substrate, matching tissue culture plates. Also, the cells could be harvested as cell patches and sheets from the scaffolds, by reducing the temperature for a short period of time, and seeded onto porous scaffolds for tissue engineering applications. An enhanced cell seeding efficiency on scaffolds was observed using the cell patch-based technique as compared to seeding cells in suspension. Owing to the already pre-existent cell–cell and cell–extracellular matrix interactions, the cell patch showed the ability to reattach rapidly onto scaffolds and showed enhanced ability to proliferate and differentiate into a bone-like matrix. (paper)

  19. Study on Dental Treatment with YAG Laser (1st Report): Temperature of Dental Tissue Irradiated with Laser Beam

    OpenAIRE

    上田, 隆司; 山田, 啓司; 古本, 達明

    2000-01-01

    The flash temperature of a dental hard tissue irradiated with pulsed Nd:YAG laser is measured using a two-color pyrometer with an optical fiber. This pyrometer consists of a chalcogenide optical fiber and a laminated infrared detector. The influence of the laser power on the temperature of the dental tissue is investigated, and the relationship between the laser power and the removal volume of the dental tissue is obtained. In order to examine the thermal damage on the dental tissue, hardness...

  20. Temperature-controlled radiofrequency ablation of cardiac tissue: an in vitro study of the impact of electrode orientation, electrode tissue contact pressure and external convective cooling

    DEFF Research Database (Denmark)

    Petersen, H H; Chen, X; Pietersen, A

    1999-01-01

    A variety of basic factors such as electrode tip pressure, flow around the electrode and electrode orientation influence lesion size during radiofrequency ablation, but importantly is dependent on the chosen mode of ablation. However, only little information is available for the frequently used...... temperature-controlled mode. The purpose of the present experimental study was to evaluate the impact during temperature-controlled radiofrequency ablation of three basic factors regarding electrode-tissue contact and convective cooling on lesion size....

  1. A Room Temperature Ultrasensitive Magnetoelectric Susceptometer for Quantitative Tissue Iron Detection

    Science.gov (United States)

    Xi, Hao; Qian, Xiaoshi; Lu, Meng-Chien; Mei, Lei; Rupprecht, Sebastian; Yang, Qing X.; Zhang, Q. M.

    2016-07-01

    Iron is a trace mineral that plays a vital role in the human body. However, absorbing and accumulating excessive iron in body organs (iron overload) can damage or even destroy an organ. Even after many decades of research, progress on the development of noninvasive and low-cost tissue iron detection methods is very limited. Here we report a recent advance in a room-temperature ultrasensitive biomagnetic susceptometer for quantitative tissue iron detection. The biomagnetic susceptometer exploits recent advances in the magnetoelectric (ME) composite sensors that exhibit an ultrahigh AC magnetic sensitivity under the presence of a strong DC magnetic field. The first order gradiometer based on piezoelectric and magnetostrictive laminate (ME composite) structure shows an equivalent magnetic noise of 0.99 nT/rt Hz at 1 Hz in the presence of a DC magnetic field of 0.1 Tesla and a great common mode noise rejection ability. A prototype magnetoelectric liver susceptometry has been demonstrated with liver phantoms. The results indicate its output signals to be linearly responsive to iron concentrations from normal iron dose (0.05 mg Fe/g liver phantom) to 5 mg Fe/g liver phantom iron overload (100X overdose). The results here open up many innovative possibilities for compact-size, portable, cost-affordable, and room-temperature operated medical systems for quantitative determinations of tissue iron.

  2. Explicit formula of finite difference method to estimate human peripheral tissue temperatures during exposure to severe cold stress.

    Science.gov (United States)

    Khanday, M A; Hussain, Fida

    2015-02-01

    During cold exposure, peripheral tissues undergo vasoconstriction to minimize heat loss to preserve the maintenance of a normal core temperature. However, vasoconstricted tissues exposed to cold temperatures are susceptible to freezing and frostbite-related tissue damage. Therefore, it is imperative to establish a mathematical model for the estimation of tissue necrosis due to cold stress. To this end, an explicit formula of finite difference method has been used to obtain the solution of Pennes' bio-heat equation with appropriate boundary conditions to estimate the temperature profiles of dermal and subdermal layers when exposed to severe cold temperatures. The discrete values of nodal temperature were calculated at the interfaces of skin and subcutaneous tissues with respect to the atmospheric temperatures of 25 °C, 20 °C, 15 °C, 5 °C, -5 °C and -10 °C. The results obtained were used to identify the scenarios under which various degrees of frostbite occur on the surface of skin as well as the dermal and subdermal areas. The explicit formula of finite difference method proposed in this model provides more accurate predictions as compared to other numerical methods. This model of predicting tissue temperatures provides researchers with a more accurate prediction of peripheral tissue temperature and, hence, the susceptibility to frostbite during severe cold exposure. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Mixed Connective Tissue Disease

    Science.gov (United States)

    Mixed connective tissue disease Overview Mixed connective tissue disease has signs and symptoms of a combination of disorders — primarily lupus, scleroderma and polymyositis. For this reason, mixed connective tissue disease ...

  4. Undifferentiated Connective Tissue Disease

    Science.gov (United States)

    ... Home Conditions Undifferentiated Connective Tissue Disease (UCTD) Undifferentiated Connective Tissue Disease (UCTD) Make an Appointment Find a Doctor ... by Barbara Goldstein, MD (February 01, 2016) Undifferentiated connective tissue disease (UCTD) is a systemic autoimmune disease. This ...

  5. Soft Tissue Sarcoma

    Science.gov (United States)

    ... muscles, tendons, fat, and blood vessels. Soft tissue sarcoma is a cancer of these soft tissues. There ... have certain genetic diseases. Doctors diagnose soft tissue sarcomas with a biopsy. Treatments include surgery to remove ...

  6. Effect of decimeter waves on brain and surrounding tissue temperature (experimental study)

    Energy Technology Data Exchange (ETDEWEB)

    Malikova, S.N.; Malyshev, V.L.; Balakyreva, V.N.; Gorban' , L.G.

    Temperature changes in brain and surrounding tissue evoked by decimeter waves (DMW) were studied on phantoms (wood shavings wetted with physiological solution), rabbits and dogs under light nembutal anesthesia and on animal cadavers. The data obtained showed that living organisms, in contrast to phantoms, exhibited a response to heat generation of DMW; this was manifested by maintenance of the temperature at certain level or by a tendency to lower it after about a 10 min exposure to DMW. Thus it was shown that there is a functional cooling system in living organisms: increased local blood flow and a specialized cooling system for the brain. Rabbits showed considerably higher brain temperature elevation than the experimental dogs. Overall, the brain temperature upon exposure to DMW depended on the intensity and duration of DMW action as well as on the state of circulating cooling system of the animals. 4 references, 4 figures.

  7. In vivo cryoablation of prostate tissue with temperature monitoring by optoacoustic imaging

    Science.gov (United States)

    Petrova, Elena V.; Motamedi, Massoud; Oraevsky, Alexander A.; Ermilov, Sergey A.

    2016-03-01

    Cryoablation of prostate cancer is an FDA approved clinical procedure, which involves repetitive rapid cooling of a lesion to lethal temperatures of -40°C and below. The major drawback of the technique is the insufficient control over the fast thermal processes that may result in severe complications (impotence, incontinence, perforation of the rectal wall) and morbidity. The developed optoacoustic imaging technique provides non-invasive real-time temperature mapping of tissue adjacent to prostate and enables more efficient control over the procedure, which is necessary to reduce side effects and accelerate the physician's learning curve. In these studies we successfully demonstrated real-time transrectal optoacoustic imaging during prostate cryoablation in live canine model focused on optoacoustic thermography of the rectal wall within the depth of 1cm. Our method utilized previously discovered universal thermal dependence of the normalized optoacoustic response of blood. Nanosecond-pulse radiation of Ti-Sapphire laser tuned to the isosbestic point of hemoglobin (802+/-3 nm) was delivered via fiberoptic illuminators assembled on both sides of the linear array of the 128-channel transrectal ultrasound probe. Temperature readouts at discrete locations inside and nearby prostate were also performed using standard transperineal needle sensors. The effect of homeostasis on optoacoustic imaging in live tissue was examined during cooling and shown to be significant only within the range of +/-1.5°C in respect to the body temperature. Accuracy of in vivo optoacoustic temperature measurements was determined as +/-2°C for the range of temperature from +35 to -15°C, which is more than sufficient for tracking the essential isotherms in the course of clinical procedures.

  8. Optimization of tissue physical parameters for accurate temperature estimation from finite-element simulation of radiofrequency ablation

    International Nuclear Information System (INIS)

    Subramanian, Swetha; Mast, T Douglas

    2015-01-01

    Computational finite element models are commonly used for the simulation of radiofrequency ablation (RFA) treatments. However, the accuracy of these simulations is limited by the lack of precise knowledge of tissue parameters. In this technical note, an inverse solver based on the unscented Kalman filter (UKF) is proposed to optimize values for specific heat, thermal conductivity, and electrical conductivity resulting in accurately simulated temperature elevations. A total of 15 RFA treatments were performed on ex vivo bovine liver tissue. For each RFA treatment, 15 finite-element simulations were performed using a set of deterministically chosen tissue parameters to estimate the mean and variance of the resulting tissue ablation. The UKF was implemented as an inverse solver to recover the specific heat, thermal conductivity, and electrical conductivity corresponding to the measured area of the ablated tissue region, as determined from gross tissue histology. These tissue parameters were then employed in the finite element model to simulate the position- and time-dependent tissue temperature. Results show good agreement between simulated and measured temperature. (note)

  9. Optimization of tissue physical parameters for accurate temperature estimation from finite-element simulation of radiofrequency ablation.

    Science.gov (United States)

    Subramanian, Swetha; Mast, T Douglas

    2015-10-07

    Computational finite element models are commonly used for the simulation of radiofrequency ablation (RFA) treatments. However, the accuracy of these simulations is limited by the lack of precise knowledge of tissue parameters. In this technical note, an inverse solver based on the unscented Kalman filter (UKF) is proposed to optimize values for specific heat, thermal conductivity, and electrical conductivity resulting in accurately simulated temperature elevations. A total of 15 RFA treatments were performed on ex vivo bovine liver tissue. For each RFA treatment, 15 finite-element simulations were performed using a set of deterministically chosen tissue parameters to estimate the mean and variance of the resulting tissue ablation. The UKF was implemented as an inverse solver to recover the specific heat, thermal conductivity, and electrical conductivity corresponding to the measured area of the ablated tissue region, as determined from gross tissue histology. These tissue parameters were then employed in the finite element model to simulate the position- and time-dependent tissue temperature. Results show good agreement between simulated and measured temperature.

  10. Tissue bionics: examples in biomimetic tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Green, David W [Bone and Joint Research Group, Developmental Origins of Health and Disease, General Hospital, University of Southampton, SO16 6YD (United Kingdom)], E-mail: Hindoostuart@googlemail.com

    2008-09-01

    Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic.

  11. Tissue bionics: examples in biomimetic tissue engineering

    International Nuclear Information System (INIS)

    Green, David W

    2008-01-01

    Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic

  12. Review Analysis of the Association between the Prevalence of Activated Brown Adipose Tissue and Outdoor Temperature

    Directory of Open Access Journals (Sweden)

    Yung-Cheng Huang

    2012-01-01

    Full Text Available Brown adipose tissue (BAT is important for regulating body weight. Environmental temperature influences BAT activation. Activated BAT is identifiable using F18-fluorodeoxyglucose positron emission tomography/computed tomography (F18-FDG PET/CT. F18-FDG PET/CT scans done between June 2005 and May 2009 in our institution in tropical southern Taiwan and BAT studies from PubMed (2002–2011 were reviewed, and the average outdoor temperatures during the study periods were obtained. A simple linear regression was used to analyze the association between the prevalence of activated BAT (P and the average outdoor temperature (T. The review analysis for 9 BAT studies (n=16,765 showed a significant negative correlation (r=-0.741, P=0.022 between the prevalence of activated BAT and the average outdoor temperature. The equation of the regression line is P(%=6.99−0.20×T  (C∘. The prevalence of activated BAT decreased by 1% for each 5C∘ increase in average outdoor temperature. In a neutral ambient temperature, the prevalence of activated BAT is low and especially rare in the tropics. There is a significant linear negative correlation between the prevalence of activated BAT and the average outdoor temperature.

  13. Temporal relation between temperature change and FDG uptake in brown adipose tissue

    International Nuclear Information System (INIS)

    Kim, SunHee; Krynyckyi, Borys R.; Machac, Josef; Kim, Chun K.

    2008-01-01

    It has been reported that the prevalence of 18 F fluorodeoxyglucose (FDG) uptake in brown adipose tissue (BAT) is related to outdoor temperature, i.e., more frequent during the colder periods of the year. The purpose of this study was to assess the temporal relationship between BAT FDG uptake and temperature. We correlated the prevalence of BAT with average temperatures (divided into five temperature ranges) of seven different durations. One thousand four hundred ninety-five consecutive FDG Positron emission tomography (PET) studies in 1,159 patients (566 male and 593 female, mean age = 60.4 years) were retrospectively reviewed. FDG uptake with distinct patterns compatible with BAT was identified by a consensus of two readers. The local daily average temperature from January 2000 to November 2003 (beginning 60 days before the date of first PET scan) were obtained, and 2-, 3-, 7-, 14-, 30-, and 60-day average temperatures before the date of a PET study were calculated. The prevalence of BAT FDG uptake was correlated with these various average temperatures. The daily, 2-day, 3-day, and 7-day average temperature had an inverse relation with the prevalence of BAT, i.e., the lower the temperature, the higher prevalence of BAT. When the temperature was averaged over 14 days or longer, this inverse relationship between the temperature and the prevalence of BAT was no longer preserved. Our data suggest that increased FDG uptake in BAT occurs more often as an acute response to cold weather (1-7 days) rather than to prolonged periods of average cold weather. (orig.)

  14. Effects of temperature and tissue type on Chrysomya rufifacies (Diptera: Calliphoridae) (Macquart) development.

    Science.gov (United States)

    Flores, Micah; Longnecker, Michael; Tomberlin, Jeffery K

    2014-12-01

    The hairy maggot blow fly, Chrysomya rufifacies (Diptera: Calliphoridae), is a forensically important fly often encountered on human and other vertebrate remains in temperate and tropic regions throughout the world including Australia, Asia, Central America and North America. C. rufifacies was reared under controlled laboratory conditions on three muscle types (i.e., porcine, equine and canine) at three temperatures (i.e., 20.8, 24.8 and 28.3°C). Rate of larval weight gain across time was statistically significant between muscle types (P≤0.0001) and approaching significance across time between temperatures (P=0.0511). This research represents the first development study for C. rufifacies from central Texas, USA and the first study to examine the impact of tissue type on its development. Furthermore, these data, when compared to those available in the literature, indicate developmental differences that could be due to genetic differences in populations or possibly methods employed during the studies. Caution should be emphasized when applying development data for this species from one region to forensic investigations in other ecoregions as such differences in development based on tissue fed upon by larvae, population genetics, and methodologies used in the studies could represent error in estimating the time of colonization. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sapin-de Brosses, E; Gennisson, J-L; Pernot, M; Fink, M; Tanter, M [Langevin Institute (CNRS UMR 7587), INSERM ERL U979, ESPCI ParisTech, 10 rue Vauquelin, 75 005 Paris (France)], E-mail: emilie.sapin@espci.fr

    2010-03-21

    Soft tissue stiffness was shown to significantly change after thermal ablation. To better understand this phenomenon, the study aims (1) to quantify and explain the temperature dependence of soft tissue stiffness for different organs, (2) to investigate the potential relationship between stiffness changes and thermal dose and (3) to study the reversibility or irreversibility of stiffness changes. Ex vivo bovine liver and muscle samples (N = 3 and N = 20, respectively) were slowly heated and cooled down into a thermally controlled saline bath. Temperatures were assessed by thermocouples. Sample stiffness (shear modulus) was provided by the quantitative supersonic shear imaging technique. Changes in liver stiffness are observed only after 45 deg. C. In contrast, between 25 deg. C and 65 deg. C, muscle stiffness varies in four successive steps that are consistent with the thermally induced proteins denaturation reported in the literature. After a 6 h long heating and cooling process, the final muscle stiffness can be either smaller or bigger than the initial one, depending on the stiffness at the end of the heating. Another important result is that stiffness changes are linked to thermal dose. Given the high sensitivity of ultrasound to protein denaturation, this study gives promising prospects for the development of ultrasound-guided HIFU systems.

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

    International Nuclear Information System (INIS)

    Sapin-de Brosses, E; Gennisson, J-L; Pernot, M; Fink, M; Tanter, M

    2010-01-01

    Soft tissue stiffness was shown to significantly change after thermal ablation. To better understand this phenomenon, the study aims (1) to quantify and explain the temperature dependence of soft tissue stiffness for different organs, (2) to investigate the potential relationship between stiffness changes and thermal dose and (3) to study the reversibility or irreversibility of stiffness changes. Ex vivo bovine liver and muscle samples (N = 3 and N = 20, respectively) were slowly heated and cooled down into a thermally controlled saline bath. Temperatures were assessed by thermocouples. Sample stiffness (shear modulus) was provided by the quantitative supersonic shear imaging technique. Changes in liver stiffness are observed only after 45 deg. C. In contrast, between 25 deg. C and 65 deg. C, muscle stiffness varies in four successive steps that are consistent with the thermally induced proteins denaturation reported in the literature. After a 6 h long heating and cooling process, the final muscle stiffness can be either smaller or bigger than the initial one, depending on the stiffness at the end of the heating. Another important result is that stiffness changes are linked to thermal dose. Given the high sensitivity of ultrasound to protein denaturation, this study gives promising prospects for the development of ultrasound-guided HIFU systems.

  17. Deep-tissue temperature mapping by multi-illumination photoacoustic tomography aided by a diffusion optical model: a numerical study

    Science.gov (United States)

    Zhou, Yuan; Tang, Eric; Luo, Jianwen; Yao, Junjie

    2018-01-01

    Temperature mapping during thermotherapy can help precisely control the heating process, both temporally and spatially, to efficiently kill the tumor cells and prevent the healthy tissues from heating damage. Photoacoustic tomography (PAT) has been used for noninvasive temperature mapping with high sensitivity, based on the linear correlation between the tissue's Grüneisen parameter and temperature. However, limited by the tissue's unknown optical properties and thus the optical fluence at depths beyond the optical diffusion limit, the reported PAT thermometry usually takes a ratiometric measurement at different temperatures and thus cannot provide absolute measurements. Moreover, ratiometric measurement over time at different temperatures has to assume that the tissue's optical properties do not change with temperatures, which is usually not valid due to the temperature-induced hemodynamic changes. We propose an optical-diffusion-model-enhanced PAT temperature mapping that can obtain the absolute temperature distribution in deep tissue, without the need of multiple measurements at different temperatures. Based on the initial acoustic pressure reconstructed from multi-illumination photoacoustic signals, both the local optical fluence and the optical parameters including absorption and scattering coefficients are first estimated by the optical-diffusion model, then the temperature distribution is obtained from the reconstructed Grüneisen parameters. We have developed a mathematic model for the multi-illumination PAT of absolute temperatures, and our two-dimensional numerical simulations have shown the feasibility of this new method. The proposed absolute temperature mapping method may set the technical foundation for better temperature control in deep tissue in thermotherapy.

  18. A cadaveric study of bone tissue temperature during pin site drilling utilizing fluoroptic thermography.

    Science.gov (United States)

    Muffly, Matthew; Winegar, Corbett; Miller, Mark Carl; Altman, Gregory

    2018-05-03

    Using fluoroptic thermography, temperature was measured during pin site drilling of intact cortical human cadaver bone with a combination of one-step drilling, graduated drilling, and one-step drilling with irrigation of 5.0 mm Schanz pins. A 1440 rpm constant force drilling was used to on tibial diaphyses while a sensor probe placed 0.5 mm adjacent to the drill hole measured temperature. Four drilling techniques on each of the tibial segments were performed: 3.5mm drill bit, 5.0mm Schanz pin, 5.0 mm Schanz pin in 3.5 mm pre-drilled entry site, 5.0 mm Schanz pin utilizing irrigation. One-step drilling using a 5.0 mm Schanz pin without irrigation produced a temperature that exceeded the threshold temperature for heat-induced injury in 5 of the 8 trials. With the other three drilling techniques, only one in24 trials produced a temperature that would result in thermal injury. This difference was found to be statistically significant (p = 0.003). The use of irrigation significantly reduced the maximum bone tissue temperature in one-step drilling of a 5.0 mm Schanz pin (p = 0.02). One-step drilling with a 3.5 mm drill bit achieved maximum temperature significantly faster than graduated drilling and drilling with irrigation using a 5.0 mm Schanz pin (p drilling with a 5.0 mm Schanz pin into cortical bone can produce temperatures that can lead to heat-induced injury. Irrigation alone can reduce the temperatures sufficiently to avoid damage. Pre-drilling can increase temperatures significantly but the extent of any injury should be small.

  19. Tolerance to low temperatures of Toxocara cati larvae in chicken muscle tissue

    DEFF Research Database (Denmark)

    Taira, Kensuke; Saitoh, Yasuhide; Okada, Natsuki

    2012-01-01

    Infectivity of Toxocara cati larvae in muscle tissue of chickens after storage at 4 degrees C and -25 degrees C was assessed in a mouse bioassay to provide information on the risk of meat-borne toxocarosis. Muscle tissue samples of 30-day old T. cati infections were stored at 4 degrees C for 14...

  20. Modeling and control of tissue compression and temperature for automation in robot-assisted surgery.

    Science.gov (United States)

    Sinha, Utkarsh; Li, Baichun; Sankaranarayanan, Ganesh

    2014-01-01

    Robotic surgery is being used widely due to its various benefits that includes reduced patient trauma and increased dexterity and ergonomics for the operating surgeon. Making the whole or part of the surgical procedure autonomous increases patient safety and will enable the robotic surgery platform to be used in telesurgery. In this work, an Electrosurgery procedure that involves tissue compression and application of heat such as the coaptic vessel closure has been automated. A MIMO nonlinear model characterizing the tissue stiffness and conductance under compression was feedback linearized and tuned PID controllers were used to control the system to achieve both the displacement and temperature constraints. A reference input for both the constraints were chosen as a ramp and hold trajectory which reflect the real constraints that exist in an actual surgical procedure. Our simulations showed that the controllers successfully tracked the reference trajectories with minimal deviation and in finite time horizon. The MIMO system with controllers developed in this work can be used to drive a surgical robot autonomously and perform electrosurgical procedures such as coaptic vessel closures.

  1. Effects of thyroidal, gonadal and adrenal hormones on tissue respiration of streaked frog, Rana limnocharis, at low temperature.

    Science.gov (United States)

    Gupta, B B; Chakrabarty, P

    1990-01-01

    In vivo and in vitro effects of thyroidal, gonadal and adrenal hormones were studied on the rate of liver and skeletal muscle respiration in both the sexes of R. limnocharis during active and inactive phases of the annual activity cycle. Triiodothyronine (L-T3) and thyroxine (L-T4) did not stimulate tissue (liver and muscle) respiration in any of the experiments irrespective of season, sex and temperature. Testosterone, estradiol and corticosterone stimulated O2 uptake significantly irrespective of season, sex and temperature. Adrenaline and nor-adrenaline also stimulated tissue respiration significantly during the winter month. Since the ambient temperature was low even during the active phase (max. temperature 21 degrees C), it seems that the frog might have developed tissue sensitivity for gonadal and adrenal hormones at low temperatures when thyroid hormones are calorigenically ineffective.

  2. Effect of laser beam on temperature distribution on artificial cylindrical shaped hard tissue bones

    Science.gov (United States)

    Al-Akhras, M.-Ali H.; Qaseer, Mohammad-Khair; Albiss, B. A.; Gezawa, Umar S.

    2018-02-01

    Samples from fresh lamb chest bones were made in cylindrical shapes to study the time variation of temperature T as functions of the cylindrical radius and depth when its front surface exposed to a laser beam of 110Mw power and 642nm wavelength. The laser beam was directed at the center of the front surface of the horizontal cylinder. The measurements were done in vacuum and at atmospheric pressure. Our data reveal the linear variation of T with time, followed by a gradual increase before it reaches a plateau value at higher time. This sort of behavior independent of the radius or the depth where the temperature was measured. Moreover, the maximum variation occurs on the front surface where the laser beam was hitting and diminishes gradually with depth deep inside the cylinder. Data at atmospheric pressure showed less changes in temperature. The temperature distribution in bone due to laser irradiation is very important for a rational use of laser therapy as well as in the surgery to minimizes the thermal tissue damage.

  3. Plant tissue culture techniques

    Directory of Open Access Journals (Sweden)

    Rolf Dieter Illg

    1991-01-01

    Full Text Available Plant cell and tissue culture in a simple fashion refers to techniques which utilize either single plant cells, groups of unorganized cells (callus or organized tissues or organs put in culture, under controlled sterile conditions.

  4. Plant Tissue Culture

    Indian Academy of Sciences (India)

    Admin

    Plant tissue culture is a technique of culturing plant cells, tissues and organs on ... working methods (Box 2) and discovery of the need for B vita- mins and auxins for ... Kotte (Germany) reported some success with growing isolated root tips.

  5. Breast reconstruction - natural tissue

    Science.gov (United States)

    ... flap; TRAM; Latissimus muscle flap with a breast implant; DIEP flap; DIEAP flap; Gluteal free flap; Transverse upper gracilis flap; TUG; Mastectomy - breast reconstruction with natural tissue; Breast cancer - breast reconstruction with natural tissue

  6. FRD tissue archive

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The fishery genetics tissue collection has over 80,000 tissues stored in 95% ethanol representing fishes and invertebrates collected globally but with a focus on the...

  7. Tissue banking in australia.

    Science.gov (United States)

    Ireland, Lynette; McKelvie, Helen

    2003-01-01

    The legal structure for the regulation of tissue banking has existed for many years. In Australia, the donation of human tissue is regulated by legislation in each of the eight States and Territories. These substantially uniform Acts were passed in the late 1970's and early 1980's, based on model legislation and underpinned by the concept of consensual giving. However, it was not until the early 1990's that tissue banking came under the notice of regulatory authorities. Since then the Australian Government has moved quickly to oversee the tissue banking sector in Australia. Banked human tissue has been deemed to be a therapeutic good under the Therapeutic Goods Act 1989, and tissue banks are required to be licensed by the Therapeutic Goods Administration and are audited for compliance with the Code of Good Manufacturing Practice- Human Blood and Tissues. In addition, tissue banks must comply with a myriad of other standards, guidelines and recommendations.

  8. Breast Cancer Tissue Repository

    National Research Council Canada - National Science Library

    Iglehart, J

    1997-01-01

    The Breast Tissue Repository at Duke enters its fourth year of finding. The purpose of the Repository at Duke is to provide substantial quantities of frozen tissue for explorative molecular studies...

  9. Connective Tissue Disorders

    Science.gov (United States)

    ... of connective tissue. Over 200 disorders that impact connective tissue. There are different types: Genetic disorders, such as Ehlers-Danlos syndrome, Marfan syndrome, and osteogenesis imperfecta Autoimmune disorders, such as lupus and scleroderma Cancers, like some types of soft tissue sarcoma Each ...

  10. Evaluation of temperature rise in a tissue mimicking material during HIFU exposure

    International Nuclear Information System (INIS)

    Maruvada, S; Liu, Y; Herman, B A; Harris, G R

    2011-01-01

    In pre-clinical testing it is essential to characterize clinical high intensity focused ultrasound (HIFU) devices using tissue-mimicking materials (TMMs) with well known characteristics, including temperature rise and cavitation properties. The purpose of this study was to monitor cavitation behavior and correlate its effect with temperature rise in a HIFU TMM containing an embedded thermocouple. A 75-μm fine wire thermocouple was embedded in a hydrogel-based TMM previously developed for HIFU. HIFU at 1.1 and 3.3 MHz was focused at the thermocouple junction. Focal pressures from 1-11 MPa were applied and the temperature profiles were recorded. Three hydrophones were used to monitor cavitation activity during sonication. A hydrophone confocal with the HIFU transducer and a cylindrical hydrophone lateral to the HIFU beam were used as passive cavitation detectors for spectral analysis of signals, and a needle hydrophone placed beyond the HIFU focus was used to record changes in the pressure amplitude due to blockage by bubbles at or near the focus. B-mode imaging scans were employed to visualize bubble presence during sonication. In a separate measurement, schlieren imaging was used to monitor the change in field distribution behind the TMM. All hydrophone methods correlated well with cavitation in the TMM.

  11. Evaluation of temperature rise in a tissue mimicking material during HIFU exposure

    Energy Technology Data Exchange (ETDEWEB)

    Maruvada, S; Liu, Y; Herman, B A; Harris, G R, E-mail: subha.maruvada@fda.hhs.gov [Food and Drug Administration, Center for Devices and Radiological Health, 10903 New Hampshire Ave., Bldg., Silver Spring, MD 20993 (United States)

    2011-02-01

    In pre-clinical testing it is essential to characterize clinical high intensity focused ultrasound (HIFU) devices using tissue-mimicking materials (TMMs) with well known characteristics, including temperature rise and cavitation properties. The purpose of this study was to monitor cavitation behavior and correlate its effect with temperature rise in a HIFU TMM containing an embedded thermocouple. A 75-{mu}m fine wire thermocouple was embedded in a hydrogel-based TMM previously developed for HIFU. HIFU at 1.1 and 3.3 MHz was focused at the thermocouple junction. Focal pressures from 1-11 MPa were applied and the temperature profiles were recorded. Three hydrophones were used to monitor cavitation activity during sonication. A hydrophone confocal with the HIFU transducer and a cylindrical hydrophone lateral to the HIFU beam were used as passive cavitation detectors for spectral analysis of signals, and a needle hydrophone placed beyond the HIFU focus was used to record changes in the pressure amplitude due to blockage by bubbles at or near the focus. B-mode imaging scans were employed to visualize bubble presence during sonication. In a separate measurement, schlieren imaging was used to monitor the change in field distribution behind the TMM. All hydrophone methods correlated well with cavitation in the TMM.

  12. Balancing photosynthetic light-harvesting and light-utilization capacities in potato leaf tissue during acclimation to different growth temperatures

    Science.gov (United States)

    Steffen, K. L.; Wheeler, R. M.; Arora, R.; Palta, J. P.; Tibbitts, T. W.

    1995-01-01

    We investigated the effect of temperature during growth and development on the relationship between light-harvesting capacity, indicated by chlorophyll concentration, and light-utilization potential, indicated by light- and bicarbonate-saturated photosynthetic oxygen evolution, in Solanum tuberosum L. cv. Norland. Clonal plantlets were transplanted and grown at 20 degrees C for 2 weeks before transfer to 12, 16, 20, 24 and 28 degrees C for 6 weeks. After 4 weeks of the temperature treatments, leaf tissue fresh weights per area were one-third higher in plants grown at 12 degrees C vs those grown at 28 degrees C. Conversely, chlorophyll content per area in tissue grown at 12 degrees C was less than one-half of that of tissue grown at 28 degrees C at 4 weeks. Photosynthetic capacity measured at a common temperature of 20 degrees C and expressed on a chlorophyll basis was inversely proportional to growth temperature. Leaf tissue from plants grown at 12 degrees C for 4 weeks had photosynthetic rates that were 3-fold higher on a chlorophyll basis than comparable tissue from plants grown at 28 degrees C. These results suggest that the relationship between light-harvesting capacity and light-utilization potential varies 3-fold in response to the growth temperatures examined. The role of this response in avoidance of photoinhibition is discussed.

  13. The effects of different lying positions on interface pressure, skin temperature, and tissue blood flow in nursing home residents.

    Science.gov (United States)

    Källman, Ulrika; Engström, Maria; Bergstrand, Sara; Ek, Anna-Christina; Fredrikson, Mats; Lindberg, Lars-Göran; Lindgren, Margareta

    2015-03-01

    Although repositioning is considered an important intervention to prevent pressure ulcers, tissue response during loading in different lying positions has not been adequately explored. To compare the effects of different lying positions on interface pressure, skin temperature, and tissue blood flow in nursing home residents. From May 2011 to August 2012, interface pressure, skin temperature, and blood flow at three tissue depths were measured for 1 hr over the sacrum in 30° supine tilt and 0° supine positions and over the trochanter major in 30° lateral and 90° lateral positions in 25 residents aged 65 years or older. Measurement of interface pressure was accomplished using a pneumatic pressure transmitter connected to a digital manometer, skin temperature using a temperature sensor, and blood flow using photoplethysmography and laser Doppler flowmetry. Interface pressure was significantly higher in the 0° supine and 90° lateral positions than in 30° supine tilt and 30° lateral positions. The mean skin temperature increased from baseline in all positions. Blood flow was significantly higher in the 30° supine tilt position compared to the other positions. A hyperemic response in the post pressure period was seen at almost all tissue depths and positions. The 30° supine tilt position generated less interface pressure and allowed greater tissue perfusion, suggesting that this position is the most beneficial. © The Author(s) 2014.

  14. Temperature Fields in Soft Tissue during LPUS Treatment: Numerical Prediction and Experiment Results

    International Nuclear Information System (INIS)

    Kujawska, Tamara; Wojcik, Janusz; Nowicki, Andrzej

    2010-01-01

    Recent research has shown that beneficial therapeutic effects in soft tissues can be induced by the low power ultrasound (LPUS). For example, increasing of cells immunity to stress (among others thermal stress) can be obtained through the enhanced heat shock proteins (Hsp) expression induced by the low intensity ultrasound. The possibility to control the Hsp expression enhancement in soft tissues in vivo stimulated by ultrasound can be the potential new therapeutic approach to the neurodegenerative diseases which utilizes the known feature of cells to increase their immunity to stresses through the Hsp expression enhancement. The controlling of the Hsp expression enhancement by adjusting of exposure level to ultrasound energy would allow to evaluate and optimize the ultrasound-mediated treatment efficiency. Ultrasonic regimes are controlled by adjusting the pulsed ultrasound waves intensity, frequency, duration, duty cycle and exposure time. Our objective was to develop the numerical model capable of predicting in space and time temperature fields induced by a circular focused transducer generating tone bursts in multilayer nonlinear attenuating media and to compare the numerically calculated results with the experimental data in vitro. The acoustic pressure field in multilayer biological media was calculated using our original numerical solver. For prediction of temperature fields the Pennes' bio-heat transfer equation was employed. Temperature field measurements in vitro were carried out in a fresh rat liver using the 15 mm diameter, 25 mm focal length and 2 MHz central frequency transducer generating tone bursts with the spatial peak temporal average acoustic intensity varied between 0.325 and 1.95 W/cm 2 , duration varied from 20 to 500 cycles at the same 20% duty cycle and the exposure time varied up to 20 minutes. The measurement data were compared with numerical simulation results obtained under experimental boundary conditions. Good agreement between the

  15. Measurement of temperature elevation in tissue for the optimum and safe use of scalpel-type ultrasonic surgery devices

    International Nuclear Information System (INIS)

    Koch, C; Nuernberger, H; Reimann, H P

    2004-01-01

    Using temperature sensors of specific design, the temperature elevation during application of a Harmonic Scalpel was determined in liver tissue. The influence of different treatment techniques and application parameters on the heat produced was determined. The measurements can be used to assess the risk of harmful bioeffects and to optimise performance and treatment techniques with respect to minimum thermal load

  16. An investigation of the flow dependence of temperature gradients near large vessels during steady state and transient tissue heating

    International Nuclear Information System (INIS)

    Kolios, M.C.; Worthington, A.E.; Hunt, J.W.; Holdsworth, D.W.; Sherar, M.D.

    1999-01-01

    Temperature distributions measured during thermal therapy are a major prognostic factor of the efficacy and success of the procedure. Thermal models are used to predict the temperature elevation of tissues during heating. Theoretical work has shown that blood flow through large blood vessels plays an important role in determining temperature profiles of heated tissues. In this paper, an experimental investigation of the effects of large vessels on the temperature distribution of heated tissue is performed. The blood flow dependence of steady state and transient temperature profiles created by a cylindrical conductive heat source and an ultrasound transducer were examined using a fixed porcine kidney as a flow model. In the transient experiments, a 20 s pulse of hot water, 30 deg. C above ambient, heated the tissues. Temperatures were measured at selected locations in steps of 0.1 mm. It was observed that vessels could either heat or cool tissues depending on the orientation of the vascular geometry with respect to the heat source and that these effects are a function of flow rate through the vessels. Temperature gradients of 6 deg. C mm -1 close to large vessels were routinely measured. Furthermore, it was observed that the temperature gradients caused by large vessels depended on whether the heating source was highly localized (i.e. a hot needle) or more distributed (i.e. external ultrasound). The gradients measured near large vessels during localized heating were between two and three times greater than the gradients measured during ultrasound heating at the same location, for comparable flows. Moreover, these gradients were more sensitive to flow variations for the localized needle heating. X-ray computed tomography data of the kidney vasculature were in good spatial agreement with the locations of all of the temperature variations measured. The three-dimensional vessel path observed could account for the complex features of the temperature profiles. The flow

  17. Cell and Tissue Engineering

    CERN Document Server

    2012-01-01

    “Cell and Tissue Engineering” introduces the principles and new approaches in cell and tissue engineering. It includes both the fundamentals and the current trends in cell and tissue engineering, in a way useful both to a novice and an expert in the field. The book is composed of 13 chapters all of which are written by the leading experts. It is organized to gradually assemble an insight in cell and tissue function starting form a molecular nano-level, extending to a cellular micro-level and finishing at the tissue macro-level. In specific, biological, physiological, biophysical, biochemical, medical, and engineering aspects are covered from the standpoint of the development of functional substitutes of biological tissues for potential clinical use. Topics in the area of cell engineering include cell membrane biophysics, structure and function of the cytoskeleton, cell-extracellular matrix interactions, and mechanotransduction. In the area of tissue engineering the focus is on the in vitro cultivation of ...

  18. Engineering Complex Tissues

    Science.gov (United States)

    MIKOS, ANTONIOS G.; HERRING, SUSAN W.; OCHAREON, PANNEE; ELISSEEFF, JENNIFER; LU, HELEN H.; KANDEL, RITA; SCHOEN, FREDERICK J.; TONER, MEHMET; MOONEY, DAVID; ATALA, ANTHONY; VAN DYKE, MARK E.; KAPLAN, DAVID; VUNJAK-NOVAKOVIC, GORDANA

    2010-01-01

    This article summarizes the views expressed at the third session of the workshop “Tissue Engineering—The Next Generation,” which was devoted to the engineering of complex tissue structures. Antonios Mikos described the engineering of complex oral and craniofacial tissues as a “guided interplay” between biomaterial scaffolds, growth factors, and local cell populations toward the restoration of the original architecture and function of complex tissues. Susan Herring, reviewing osteogenesis and vasculogenesis, explained that the vascular arrangement precedes and dictates the architecture of the new bone, and proposed that engineering of osseous tissues might benefit from preconstruction of an appropriate vasculature. Jennifer Elisseeff explored the formation of complex tissue structures based on the example of stratified cartilage engineered using stem cells and hydrogels. Helen Lu discussed engineering of tissue interfaces, a problem critical for biological fixation of tendons and ligaments, and the development of a new generation of fixation devices. Rita Kandel discussed the challenges related to the re-creation of the cartilage-bone interface, in the context of tissue engineered joint repair. Frederick Schoen emphasized, in the context of heart valve engineering, the need for including the requirements derived from “adult biology” of tissue remodeling and establishing reliable early predictors of success or failure of tissue engineered implants. Mehmet Toner presented a review of biopreservation techniques and stressed that a new breakthrough in this field may be necessary to meet all the needs of tissue engineering. David Mooney described systems providing temporal and spatial regulation of growth factor availability, which may find utility in virtually all tissue engineering and regeneration applications, including directed in vitro and in vivo vascularization of tissues. Anthony Atala offered a clinician’s perspective for functional tissue

  19. Low-temperature deposition manufacturing: A novel and promising rapid prototyping technology for the fabrication of tissue-engineered scaffold.

    Science.gov (United States)

    Liu, Wei; Wang, Daming; Huang, Jianghong; Wei, You; Xiong, Jianyi; Zhu, Weimin; Duan, Li; Chen, Jielin; Sun, Rong; Wang, Daping

    2017-01-01

    Developed in recent years, low-temperature deposition manufacturing (LDM) represents one of the most promising rapid prototyping technologies. It is not only based on rapid deposition manufacturing process but also combined with phase separation process. Besides the controlled macropore size, tissue-engineered scaffold fabricated by LDM has inter-connected micropores in the deposited lines. More importantly, it is a green manufacturing process that involves non-heating liquefying of materials. It has been employed to fabricate tissue-engineered scaffolds for bone, cartilage, blood vessel and nerve tissue regenerations. It is a promising technology in the fabrication of tissue-engineered scaffold similar to ideal scaffold and the design of complex organs. In the current paper, this novel LDM technology is introduced, and its control parameters, biomedical applications and challenges are included and discussed as well. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Measuring surface temperature and grading pathological changes of airway tissue in a canine model of inhalational thermal injury.

    Science.gov (United States)

    Zhao, Ran; Di, La-na; Zhao, Xiao-zhuo; Wang, Cheng; Zhang, Guo-an

    2013-06-01

    Airway tissue shows unexpected invulnerability to heated air. The mechanisms of this phenomenon are open to debate. This study was designed to measure the surface temperatures at different locations of the airway, and to explore the relationship between the tissue's surface temperature and injury severity. Twenty dogs were randomly divided into four groups, including three experimental groups (six dogs in each) to inhale heated air at 70-80 °C (group I), 150-160 °C (group II) and 310-320 °C (group III) and a control group (two dogs, only for histological observation). Injury time was 20 min. Mucosal surface temperatures of the epiglottis (point A), cricoid cartilage (point B) and lower trachea (point C) were measured. Dogs in group I-III were divided into three subgroups (two in each), to be assayed at 12, 24 and 36 h after injury, respectively. For each dog, four tissue parts (epiglottis, larynx, lower trachea and terminal bronchiole) were microscopically observed and graded according to an original pathological scoring system (score range: 0-27). Surface temperatures of the airway mucosa increased slowly to 40.60±3.29 °C, and the highest peak temperature was 48.3 °C (group III, point A). The pathological score of burned tissues was 4.12±4.94 (0.0-18.0), suggesting slight to moderate injuries. Air temperature and airway location both influenced mucosal temperature and pathological scores very significantly, and there was a very significant positive correlation between tissue temperature and injury severity. Compared to the inhalational air hyperthermia, airway surface temperature was much lower, but was still positively correlated with thermal injury severity. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  1. Monitoring of temperature-mediated phase transitions of adipose tissue by combined optical coherence tomography and Abbe refractometry.

    Science.gov (United States)

    Yanina, Irina Y; Popov, Alexey P; Bykov, Alexander V; Meglinski, Igor V; Tuchin, Valery V

    2018-01-01

    Observation of temperature-mediated phase transitions between lipid components of the adipose tissues has been performed by combined use of the Abbe refractometry and optical coherence tomography. The phase transitions of the lipid components were clearly observed in the range of temperatures from 24°C to 60°C, and assessed by quantitatively monitoring the changes of the refractive index of 1- to 2-mm-thick porcine fat tissue slices. The developed approach has a great potential as an alternative method for obtaining accurate information on the processes occurring during thermal lipolysis. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  2. Study of the temperature rise induced by a focusing transducer with a wide aperture angle on biological tissue containing ribs

    International Nuclear Information System (INIS)

    Wang Xin; Lin Jiexing; Liu Xiaozhou; Liu Jiehui; Gong Xiufen

    2016-01-01

    We used the spheroidal beam equation to calculate the sound field created by focusing a transducer with a wide aperture angle to obtain the heat deposition, and then we used the Pennes bioheat equation to calculate the temperature field in biological tissue with ribs and to ascertain the effects of rib parameters on the temperature field. The results show that the location and the gap width between the ribs have a great influence on the axial and radial temperature rise of multilayer biological tissue. With a decreasing gap width, the location of the maximum temperature rise moves forward; as the ribs are closer to the transducer surface, the sound energy that passes through the gap between the ribs at the focus decreases, the maximum temperature rise decreases, and the location of the maximum temperature rise moves forward with the ribs. (paper)

  3. Effect of therapeutic ultrasound intensity on subcutaneous tissue temperature and ulnar nerve conduction velocity.

    Science.gov (United States)

    Kramer, J F

    1985-02-01

    Twenty subjects completed 5 min. periods of sonation, at each of six US intensities, over the ulnar nerve in the proximal forearm. All posttreatment NCV's differed significantly from the respective pretreatment velocities. The immediate posttreatment NCV associated with placebo US was significantly (p less than 0.01) less than that observed immediately pretreatment (2.81 m/s), while the five clinical US intensities produced significantly increased immediate posttreatment velocities: 0.5 w/cm2 (2.23 m/s) at (p less than 0.05), and 1.0 w/cm2 (2.78 m/s), 1.5 w/cm2 (3.15 m/s), 2.0 w/cm2 (4.47 m/s) and 2.5 w/cm2 (2.97 m/s) at (p less than 0.01). The posttreatment velocities associated with the five clinical intensities were all significantly greater (p less than 0.01) than that associated with placebo US. Subcutaneous tissue temperatures were directly related to the intensity of US. Not until US intensity had reached 1.5 w/cm2 did the heating effect of US negate the cooling effect of the US transmission gel, to produce significantly increased subcutaneous tissue temperatures after 5 min. sonation. The decreased ulnar motor NCV's associated with placebo US are attributed to the cooling effect of the US transmission gel. The increased ulnar motor NCV's associated with the clinical intensities of US are attributed to the deep heating effect of US. The breakdown of this linear relationship at 2.5 w/cm2 intensity suggests that at this point heating on the nerve and/or the mechanical effects of US were of sufficient magnitude so as to limit the increase in conduction velocity. Sonation over an area of approximately 4.5 times the soundhead for 5 min., along the proximal forearm, at clinical intensities did not have a bipositive effect on motor NCV.

  4. Engineering Musculoskeletal Tissue Interfaces

    Directory of Open Access Journals (Sweden)

    Ece Bayrak

    2018-04-01

    Full Text Available Tissue engineering aims to bring together biomaterials, cells, and signaling molecules within properly designed microenvironments in order to create viable treatment options for the lost or malfunctioning tissues. Design and production of scaffolds and cell-laden grafts that mimic the complex structural and functional features of tissues are among the most important elements of tissue engineering strategy. Although all tissues have their own complex structure, an even more complex case in terms of engineering a proper carrier material is encountered at the tissue interfaces, where two distinct tissues come together. The interfaces in the body can be examined in four categories; cartilage-bone and ligament-bone interfaces at the knee and the spine, tendon-bone interfaces at the shoulder and the feet, and muscle-tendon interface at the skeletal system. These interfaces are seen mainly at the soft-to-hard tissue transitions and they are especially susceptible to injury and tear due to the biomechanical inconsistency between these tissues where high strain fields are present. Therefore, engineering the musculoskeletal tissue interfaces remain a challenge. This review focuses on recent advancements in strategies for musculoskeletal interface engineering using different biomaterial-based platforms and surface modification techniques.

  5. Proteome changes in banana fruit peel tissue in response to ethylene and high-temperature treatments.

    Science.gov (United States)

    Du, Lina; Song, Jun; Forney, Charles; Palmer, Leslie Campbell; Fillmore, Sherry; Zhang, ZhaoQi

    2016-01-01

    Banana (Musa AAA group) is one of the most consumed fruits in the world due to its flavor and nutritional value. As a typical climacteric fruit, banana responds to ethylene treatment, which induces rapid changes of color, flavor (aroma and taste), sweetness and nutritional composition. It has also been reported that ripening bananas at temperatures above 24 °C inhibits chlorophyll breakdown and color formation but increases the rate of senescence. To gain fundamental knowledge about the effects of high temperature and ethylene on banana ripening, a quantitative proteomic study employing multiplex peptide stable isotope dimethyl labeling was conducted. In this study, green (immature) untreated banana fruit were subjected to treatment with 10 μL L(-1) of ethylene for 24 h. After ethylene treatment, treated and untreated fruit were stored at 20 or 30 °C for 24 h. Fruit peel tissues were then sampled after 0 and 1 day of storage, and peel color and chlorophyll fluorescence were evaluated. Quantitative proteomic analysis was conducted on the fruit peels after 1 day of storage. In total, 413 common proteins were identified and quantified from two biological replicates. Among these proteins, 91 changed significantly in response to ethylene and high-temperature treatments. Cluster analysis on these 91 proteins identified 7 groups of changed proteins. Ethylene treatment and storage at 20 °C induced 40 proteins that are correlated with pathogen resistance, cell wall metabolism, ethylene biosynthesis, allergens and ribosomal proteins, and it repressed 36 proteins that are associated with fatty acid and lipid metabolism, redox-oxidative responses, and protein biosynthesis and modification. Ethylene treatment and storage at 30 °C induced 32 proteins, which were mainly similar to those in group 1 but also included 8 proteins in group 3 (identified as chitinase, cinnamyl alcohol dehydrogenase 1, cysteine synthase, villin-2, leucine-transfer RNA ligase, CP47

  6. Temperature dynamics of soft tissues during diode laser cutting by different types of fiber opto-thermal converters

    Science.gov (United States)

    Belikov, Andrey V.; Skrypnik, Alexei V.; Smirnov, Sergey N.; Semyashkina, Yulia V.

    2017-03-01

    The results of in vitro study of the soft tissue temperature dynamics during 980 nm diode laser cutting by different types (CLEAR, FILM, VOLUMETRIC) of fiber opto-thermal converters (FOTC) are presented. It was found that the use of CLEAR fiber end (tip) at the laser power below 8.5 W doesn't lead to the soft tissue (chicken meat) destruction. The chicken meat destruction (cutting) begins when irradiated by 8.5 W laser radiation for approximately 9.0 s. At the power of 9.0 W this time decreases up to 7.0 s, at 9.5 W - to 6.0 s, at 10.0 W - to 3.5 s. The moment of soft tissue cutting start correlates with the moment of black layer (absorber) formation at the fiber end and appearance of visually identifiable laser cut walls on the photos; the temperature in this case rapidly increases up to 850 °C. It was determined that the FILM FOTC begins to cut the soft tissue immediately after exposure of laser radiation with power of 4.0 W, the temperature in this case reaches 900 °C. It was determined that the VOLUMETRIC FOTC begins to cut the tissue immediately after exposure at the power of 1.0 W, the temperature in this case reaches 600 °C. VOLUMETRIC FOTC can produce more effective cuts of the soft tissue at the laser power of 4.0 W, in this case, the temperature is above 1200 °C.

  7. DNA from keratinous tissue

    DEFF Research Database (Denmark)

    Bengtsson, Camilla F.; Olsen, Maja E.; Brandt, Luise Ørsted

    2011-01-01

    Keratinous tissues such as nail, hair, horn, scales and feather have been used as a source of DNA for over 20 years. Particular benefits of such tissues include the ease with which they can be sampled, the relative stability of DNA in such tissues once sampled, and, in the context of ancient...... genetic analyses, the fact that sampling generally causes minimal visual damage to valuable specimens. Even when freshly sampled, however, the DNA quantity and quality in the fully keratinized parts of such tissues is extremely poor in comparison to other tissues such as blood and muscle – although little...... systematic research has been undertaken to characterize how such degradation may relate to sample source. In this review paper we present the current understanding of the quality and limitations of DNA in two key keratinous tissues, nail and hair. The findings indicate that although some fragments of nuclear...

  8. Tissue engineering in dentistry.

    Science.gov (United States)

    Abou Neel, Ensanya Ali; Chrzanowski, Wojciech; Salih, Vehid M; Kim, Hae-Won; Knowles, Jonathan C

    2014-08-01

    of this review is to inform practitioners with the most updated information on tissue engineering and its potential applications in dentistry. The authors used "PUBMED" to find relevant literature written in English and published from the beginning of tissue engineering until today. A combination of keywords was used as the search terms e.g., "tissue engineering", "approaches", "strategies" "dentistry", "dental stem cells", "dentino-pulp complex", "guided tissue regeneration", "whole tooth", "TMJ", "condyle", "salivary glands", and "oral mucosa". Abstracts and full text articles were used to identify causes of craniofacial tissue loss, different approaches for craniofacial reconstructions, how the tissue engineering emerges, different strategies of tissue engineering, biomaterials employed for this purpose, the major attempts to engineer different dental structures, finally challenges and future of tissue engineering in dentistry. Only those articles that dealt with the tissue engineering in dentistry were selected. There have been a recent surge in guided tissue engineering methods to manage periodontal diseases beyond the traditional approaches. However, the predictable reconstruction of the innate organisation and function of whole teeth as well as their periodontal structures remains challenging. Despite some limited progress and minor successes, there remain distinct and important challenges in the development of reproducible and clinically safe approaches for oral tissue repair and regeneration. Clearly, there is a convincing body of evidence which confirms the need for this type of treatment, and public health data worldwide indicates a more than adequate patient resource. The future of these therapies involving more biological approaches and the use of dental tissue stem cells is promising and advancing. Also there may be a significant interest of their application and wider potential to treat disorders beyond the craniofacial region. Considering the

  9. Biomaterials for Tissue Engineering

    Science.gov (United States)

    Lee, Esther J.; Kasper, F. Kurtis; Mikos, Antonios G.

    2013-01-01

    Biomaterials serve as an integral component of tissue engineering. They are designed to provide architectural framework reminiscent of native extracellular matrix in order to encourage cell growth and eventual tissue regeneration. Bone and cartilage represent two distinct tissues with varying compositional and mechanical properties. Despite these differences, both meet at the osteochondral interface. This article presents an overview of current biomaterials employed in bone and cartilage applications, discusses some design considerations, and alludes to future prospects within this field of research. PMID:23820768

  10. Can tissues be owned?

    African Journals Online (AJOL)

    2013-06-17

    Jun 17, 2013 ... Regulations Regarding Rendering of Clinical Forensic Medicine ... 1 Special Interest Research Group on Biotechnology and Medical Law of the College of Law, University of ... persons for the following medical and dental purposes: ... tissue to the international market were taking tissue without consent.

  11. Neural tissue-spheres

    DEFF Research Database (Denmark)

    Andersen, Rikke K; Johansen, Mathias; Blaabjerg, Morten

    2007-01-01

    By combining new and established protocols we have developed a procedure for isolation and propagation of neural precursor cells from the forebrain subventricular zone (SVZ) of newborn rats. Small tissue blocks of the SVZ were dissected and propagated en bloc as free-floating neural tissue...... content, thus allowing experimental studies of neural precursor cells and their niche...

  12. Two-dimensional real-time blood flow and temperature of soft tissue around maxillary anterior implants.

    Science.gov (United States)

    Nakamoto, Tetsuji; Kanao, Masato; Kondo, Yusuke; Kajiwara, Norihiro; Masaki, Chihiro; Takahashi, Tetsu; Hosokawa, Ryuji

    2012-12-01

    The aims of this study were to (1) evaluate the basic nature of soft tissue surrounding maxillary anterior implants by simultaneous measurements of blood flow and surface temperature and (2) analyze differences with and without bone grafting associated with implant placement to try to detect the signs of surface morphology change. Twenty maxillary anterior implant patients, 10 bone grafting and 10 graftless, were involved in this clinical trial. Soft tissue around the implant was evaluated with 2-dimensional laser speckle imaging and a thermograph. Blood flow was significantly lower in attached gingiva surrounding implants in graftless patients (P = 0.0468). On the other hand, it was significantly lower in dental papillae (P = 0.0254), free gingiva (P = 0.0198), and attached gingiva (P = 0.00805) in bone graft patients. Temperature was significantly higher in free gingiva (P = 0.00819) and attached gingiva (P = 0.00593) in graftless patients, whereas it was significantly higher in dental papilla and free gingiva in implants with bone grafting. The results suggest that simultaneous measurements of soft-tissue blood flow and temperature is a useful technique to evaluate the microcirculation of soft tissue surrounding implants.

  13. Temperature of cutaneous and subcutaneous tissue during the application of aerosols in rats

    OpenAIRE

    Andre de Oliveira Teixeira; Cassio Noronha Martins; Antônio Marcos Vargas da Silva; Alexandro Marques Tozetti; Rodrigo Della Méa Plentz; Luis Ulisses Signori

    2014-01-01

    This study compared the thermal changes of cutaneous and subcutaneous tissues exposed to different aerosols. Thirty-six adults Wistar rats were arranged in two treatment groups, one exposed to methyl salicylate (GSM; n = 9 skin and n = 9 subcutaneous) and the other exposed to diclofenac diethylammonium (GDD; n = 9 skin and n = 9 subcutaneous) aerosols. Five jets were applied for one-second through an apparatus to reduce spray dispersion (3 cmdiameter) in the lateral left thigh of the animals....

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

    Directory of Open Access Journals (Sweden)

    Zhihua Sun

    2012-01-01

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

  15. Synovial tissue research

    DEFF Research Database (Denmark)

    Orr, Carl; Sousa, Elsa; Boyle, David L

    2017-01-01

    The synovium is the major target tissue of inflammatory arthritides such as rheumatoid arthritis. The study of synovial tissue has advanced considerably throughout the past few decades from arthroplasty and blind needle biopsy to the use of arthroscopic and ultrasonographic technologies that enable...... easier visualization and improve the reliability of synovial biopsies. Rapid progress has been made in using synovial tissue to study disease pathogenesis, to stratify patients, to discover biomarkers and novel targets, and to validate therapies, and this progress has been facilitated by increasingly...... diverse and sophisticated analytical and technological approaches. In this Review, we describe these approaches, and summarize how their use in synovial tissue research has improved our understanding of rheumatoid arthritis and identified candidate biomarkers that could be used in disease diagnosis...

  16. Optical tomography of tissues

    International Nuclear Information System (INIS)

    Zimnyakov, D A; Tuchin, Valerii V

    2002-01-01

    Methods of optical tomography of biological tissues are considered, which include pulse-modulation and frequency-modulation tomography, diffusion tomography with the use of cw radiation sources, optical coherent tomography, speckle-correlation tomography of nonstationary media, and optoacoustic tomography. The method for controlling the optical properties of tissues is studied from the point of view of increasing a probing depth in optical coherent tomography. The modern state and prospects of the development of optical tomography are discussed. (review)

  17. Tissue Damage, Temperature, and pH Induced by Different Electrode Arrays on Potato Pieces (Solanum tuberosum L.

    Directory of Open Access Journals (Sweden)

    Maraelys Morales González

    2018-04-01

    Full Text Available One of the most challenging problems of electrochemical therapy is the design and selection of suitable electrode array for cancer. The aim is to determine how two-dimensional spatial patterns of tissue damage, temperature, and pH induced in pieces of potato (Solanum tuberosum L., var. Mondial depend on electrode array with circular, elliptical, parabolic, and hyperbolic shape. The results show the similarity between the shapes of spatial patterns of tissue damage and electric field intensity, which, like temperature and pH take the same shape of electrode array. The adequate selection of suitable electrodes array requires an integrated analysis that involves, in a unified way, relevant information about the electrochemical process, which is essential to perform more efficiently way the therapeutic planning and the personalized therapy for patients with a cancerous tumor.

  18. A measurement and modeling study of temperature in living and fixed tissue during and after radiofrequency exposure.

    Science.gov (United States)

    Bermingham, Jacqueline F; Chen, Yuen Y; McIntosh, Robert L; Wood, Andrew W

    2014-04-01

    Fluorescent intensity of the dye Rhodamine-B (Rho-B) decreases with increasing temperature. We show that in fresh rat brain tissue samples in a custom-made radiofrequency (RF) tissue exposure device, temperature rise due to RF radiation as measured by absorbed dye correlates well with temperature measured nearby by fiber optic probes. Estimates of rate of initial temperature rise (using both probe measurement and the dye method) accord well with estimates of local specific energy absorption rate (SAR). We also modeled the temperature characteristics of the exposure device using combined electromagnetic and finite-difference thermal modeling. Although there are some differences in the rate of cooling following cessation of RF exposure, there is reasonable agreement between modeling and both probe measurement and dye estimation of temperature. The dye method also permits measurement of regional temperature rise (due to RF). There is no clear evidence of local differential RF absorption, but further refinement of the method may be needed to fully clarify this issue. © 2014 Wiley Periodicals, Inc.

  19. Temperature simulations in hyperthermia treatment planning of the head and neck region. Rigorous optimization of tissue properties

    International Nuclear Information System (INIS)

    Verhaart, Rene F.; Rijnen, Zef; Verduijn, Gerda M.; Paulides, Margarethus M.; Fortunati, Valerio; Walsum, Theo van; Veenland, Jifke F.

    2014-01-01

    Hyperthermia treatment planning (HTP) is used in the head and neck region (H and N) for pretreatment optimization, decision making, and real-time HTP-guided adaptive application of hyperthermia. In current clinical practice, HTP is based on power-absorption predictions, but thermal dose-effect relationships advocate its extension to temperature predictions. Exploitation of temperature simulations requires region- and temperature-specific thermal tissue properties due to the strong thermoregulatory response of H and N tissues. The purpose of our work was to develop a technique for patient group-specific optimization of thermal tissue properties based on invasively measured temperatures, and to evaluate the accuracy achievable. Data from 17 treated patients were used to optimize the perfusion and thermal conductivity values for the Pennes bioheat equation-based thermal model. A leave-one-out approach was applied to accurately assess the difference between measured and simulated temperature (∇T). The improvement in ∇T for optimized thermal property values was assessed by comparison with the ∇T for values from the literature, i.e., baseline and under thermal stress. The optimized perfusion and conductivity values of tumor, muscle, and fat led to an improvement in simulation accuracy (∇T: 2.1 ± 1.2 C) compared with the accuracy for baseline (∇T: 12.7 ± 11.1 C) or thermal stress (∇T: 4.4 ± 3.5 C) property values. The presented technique leads to patient group-specific temperature property values that effectively improve simulation accuracy for the challenging H and N region, thereby making simulations an elegant addition to invasive measurements. The rigorous leave-one-out assessment indicates that improvements in accuracy are required to rely only on temperature-based HTP in the clinic. (orig.) [de

  20. Calf blood flow at rest evaluated by thermal measurement with tissue temperature and heat flow and 133Xe clearance

    International Nuclear Information System (INIS)

    Tamura, Toshiyo; Togawa, Tatsuo; Fukuoka, Masakazu; Kawakami, Kenji.

    1982-01-01

    The regional blood flow in the calf was determined simultaneously by thermal measurement and by 133 Xe clearance technique. Calf blood flow (Ft) by thermal measurement was accounted for by the equation of the form Ft=(CdT*d+Ho-Mb)/rho sub(b)c su b(D) (Ta-Td), where Cd is thermal capacitance of the calf compartment, T*d is the change of calf tissue temperature, Ta is arterila blood temperature, Td is calf tissue temperature, Ho is the heat dissipation from the compartment to the environment, Mb is estimated metabolism of the calf tissue and rho sub(b)c sub(b) is the product of density and specific heat of blood. The healthy men were chosen for the experiments. Total calf blood flow was 2.53+-1.31ml/(min-100ml calf), and muscle blood flow was 2.63+-1.69ml/(min- 100ml muscle) and skin blood flow 7.19+-3.83ml/(min-100ml skin) measured by 133 Xe clearance. On the basis of the results, an estimate has been made of the proportions of the calf volume which can be ascribed to skin and muscle respectively. Estimated muscle and skin blood flow were correlated with total calf blood flow(r=0.98). (author)

  1. [Connective tissue and inflammation].

    Science.gov (United States)

    Jakab, Lajos

    2014-03-23

    The author summarizes the structure of the connective tissues, the increasing motion of the constituents, which determine the role in establishing the structure and function of that. The structure and function of the connective tissue are related to each other in the resting as well as inflammatory states. It is emphasized that cellular events in the connective tissue are part of the defence of the organism, the localisation of the damage and, if possible, the maintenance of restitutio ad integrum. The organism responds to damage with inflammation, the non specific immune response, as well as specific, adaptive immunity. These processes are located in the connective tissue. Sterile and pathogenic inflammation are relatively similar processes, but inevitable differences are present, too. Sialic acids and glycoproteins containing sialic acids have important roles, and the role of Siglecs is also highlighted. Also, similarities and differences in damages caused by pathogens and sterile agents are briefly summarized. In addition, the roles of adhesion molecules linked to each other, and the whole event of inflammatory processes are presented. When considering practical consequences it is stressed that the structure (building up) of the organism and the defending function of inflammation both have fundamental importance. Inflammation has a crucial role in maintaining the integrity and the unimpaired somato-psychological state of the organism. Thus, inflammation serves as a tool of organism identical with the natural immune response, inseparably connected with the specific, adaptive immune response. The main events of the inflammatory processes take place in the connective tissue.

  2. Autopsy Tissue Program

    International Nuclear Information System (INIS)

    Fox, T.; Tietjen, G.

    1979-01-01

    The Autopsy Tissue Program was begun in 1960. To date, tissues on 900 or more persons in 7 geographic regions have been collected and analyzed for plutonium content. The tissues generally consist of lung, liver, kidney, lymph, bone, and gonadal tissue for each individual. The original objective of the program was to determine the level of plutonium in human tissues due solely to fall-out from weapons testing. The baseline thus established was to be used to evaluate future changes. From the first, this program was beset with chemical and statistical difficulties. Many factors whose effects were not recognized and not planned for were found later to be important. Privacy and ethical considerations hindered the gathering of adequate data. Since the chemists were looking for amounts of plutonium very close to background, possible contamination was a very real problem. Widely used chemical techniques introduced a host of statistical problems. The difficulties encountered touch on areas common to large data sets, unusual outlier detection methods, minimum detection limits, problems with Aliquot sizes, and time-trends in the data. The conclusions point out areas to which the biologists will have to devote much more careful attention than was believed

  3. Morphology of urethral tissues

    Science.gov (United States)

    Müller, Bert; Schulz, Georg; Herzen, Julia; Mushkolaj, Shpend; Bormann, Therese; Beckmann, Felix; Püschel, Klaus

    2010-09-01

    Micro computed tomography has been developed to a powerful technique for the characterization of hard and soft human and animal tissues. Soft tissues including the urethra, however, are difficult to be analyzed, since the microstructures of interest exhibit X-ray absorption values very similar to the surroundings. Selective staining using highly absorbing species is a widely used approach, but associated with significant tissue modification. Alternatively, one can suitably embed the soft tissue, which requires the exchange of water. Therefore, the more recently developed phase contrast modes providing much better contrast of low X-ray absorbing species are especially accommodating in soft tissue characterization. The present communication deals with the morphological characterization of sheep, pig and human urethras on the micrometer scale taking advantage of micro computed tomography in absorption and phase contrast modes. The performance of grating-based tomography is demonstrated for freshly explanted male and female urethras in saline solution. The micro-morphology of the urethra is important to understand how the muscles close the urethra to reach continence. As the number of incontinent patients is steadily increasing, the function under static and, more important, under stress conditions has to be uncovered for the realization of artificial urinary sphincters, which needs sophisticated, biologically inspired concepts to become nature analogue.

  4. Comparison of the Viability of Cryopreserved Fat Tissue in Accordance with the Thawing Temperature

    Directory of Open Access Journals (Sweden)

    So-Min Hwang

    2015-03-01

    Full Text Available BackgroundAdipose tissue damage of cryopreserved fat after autologous fat transfer is inevitable in several processes of re-transplantation. This study aims to compare and analyze the survivability of adipocytes after thawing fat cryopreserved at -20℃ by using thawing methods used in clinics.MethodsThe survival rates of adipocytes in the following thawing groups were measured: natural thawing at 25℃ for 15 minutes; natural thawing at 25℃ for 5 minutes, followed by rapid thawing at 37℃ in a water bath for 5 minutes; and rapid thawing at 37℃ for 10 minutes in a water bath. The survival rates of adipocytes were assessed by measuring the volume of the fat layer in the top layers separated after centrifugation, counting the number of live adipocytes after staining with trypan blue, and measuring the activity of mitochondria in the adipocytes.ResultsIn the group with rapid thawing for 10 minutes in a water bath, it was observed that the cell count of live adipocytes and the activity of the adipocyte mitochondria were significantly higher than in the other two groups (P<0.05. The volume of the fat layer separated by centrifugation was also measured to be higher, which was, however, not statistically significant.ConclusionsIt was shown that the survival rate of adipocytes was higher when the frozen fat tissue was thawed rapidly at 37℃. It can thus be concluded that if fats thawed with this method are re-transplanted, the survival rate of cryopreserved fats in transplantation will be improved, and thus, the effect of autologous fat transfer will increase.

  5. The use of a DNA stabilizer in human dental tissues stored under different temperature conditions and time intervals

    Science.gov (United States)

    TERADA, Andrea Sayuri Silveira Dias; da SILVA, Luiz Antonio Ferreira; GALO, Rodrigo; de AZEVEDO, Aline; GERLACH, Raquel Fernanda; da SILVA, Ricardo Henrique Alves

    2014-01-01

    Objective The present study evaluated the use of a reagent to stabilize the DNA extracted from human dental tissues stored under different temperature conditions and time intervals. Material and Methods A total of 161 teeth were divided into two distinct groups: intact teeth and isolated dental pulp tissue. The samples were stored with or without the product at different time intervals and temperature. After storage, DNA extraction and genomic DNA quantification were performed using real-time PCR; the fragments of the 32 samples that represented each possible condition were analyzed to find the four pre-selected markers in STR analysis. Results The results of the quantification showed values ranging from 0.01 to 10,246.88 ng/μL of DNA. The statistical difference in the quantity of DNA was observed when the factors related to the time and temperature of storage were analyzed. In relation to the use of the specific reagent, its use was relevant in the group of intact teeth when they were at room temperature for 30 and 180 days. The analysis of the fragments in the 32 selected samples was possible irrespective of the amount of DNA, confirming that the STR analysis using an automated method yields good results. Conclusions The use of a specific reagent showed a significant difference in stabilizing DNA in samples of intact human teeth stored at room temperature for 30 and 180 days, while the results showed no justification for using the product under the other conditions tested. PMID:25141206

  6. Black-box modeling to estimate tissue temperature during radiofrequency catheter cardiac ablation: feasibility study on an agar phantom model

    International Nuclear Information System (INIS)

    Blasco-Gimenez, Ramón; Lequerica, Juan L; Herrero, Maria; Hornero, Fernando; Berjano, Enrique J

    2010-01-01

    The aim of this work was to study linear deterministic models to predict tissue temperature during radiofrequency cardiac ablation (RFCA) by measuring magnitudes such as electrode temperature, power and impedance between active and dispersive electrodes. The concept involves autoregressive models with exogenous input (ARX), which is a particular case of the autoregressive moving average model with exogenous input (ARMAX). The values of the mode parameters were determined from a least-squares fit of experimental data. The data were obtained from radiofrequency ablations conducted on agar models with different contact pressure conditions between electrode and agar (0 and 20 g) and different flow rates around the electrode (1, 1.5 and 2 L min −1 ). Half of all the ablations were chosen randomly to be used for identification (i.e. determination of model parameters) and the other half were used for model validation. The results suggest that (1) a linear model can be developed to predict tissue temperature at a depth of 4.5 mm during RF cardiac ablation by using the variables applied power, impedance and electrode temperature; (2) the best model provides a reasonably accurate estimate of tissue temperature with a 60% probability of achieving average errors better than 5 °C; (3) substantial errors (larger than 15 °C) were found only in 6.6% of cases and were associated with abnormal experiments (e.g. those involving the displacement of the ablation electrode) and (4) the impact of measuring impedance on the overall estimate is negligible (around 1 °C)

  7. Skeletal muscle connective tissue

    DEFF Research Database (Denmark)

    Brüggemann, Dagmar Adeline

    in the structure of fibrous collagen and myofibers at high-resolution. The results demonstrate that the collagen composition in the extra cellular matrix of Gadus morhua fish muscle is much more complex than previously anticipated, as it contains type III, IV, V  and VI collagen in addition to type I. The vascular....... Consequently, functional structures, ensuring "tissue maintenance" must form a major role of connective tissue, in addition that is to the force transmitting structures one typically finds in muscle. Vascular structures have also been shown to change their mechanical properties with age and it has been shown...

  8. Failure in cartilaginous tissues

    NARCIS (Netherlands)

    Huyghe, J.M.R.J.; Talen-Jongeneelen, C.J.M.; Schroeder, Y.; Kraaijeveld, F.; Borst, de R.; Baaijens, F.P.T.

    2007-01-01

    Cartilaginous tissues high load bearing capacity is explained by osmotic prestressing putting the collagen fiber reinforcement under tension and the proteoglycan gel under compression. The osmotic forces are boosted by a further 50 % by the affinity of the collagen with the aquous solution. The high

  9. Connective tissue activation. XVII

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  10. Soft Tissue Extramedullary Plasmacytoma

    Directory of Open Access Journals (Sweden)

    Fernando Ruiz Santiago

    2010-01-01

    Full Text Available We present the uncommon case of a subcutaneous fascia-based extramedullary plasmacytoma in the leg, which was confirmed by the pathology report and followed up until its remission. We report the differential diagnosis with other more common soft tissue masses. Imaging findings are nonspecific but are important to determine the tumour extension and to plan the biopsy.

  11. Neoproteoglycans in tissue engineering

    Science.gov (United States)

    Weyers, Amanda; Linhardt, Robert J.

    2014-01-01

    Proteoglycans, comprised of a core protein to which glycosaminoglycan chains are covalently linked, are an important structural and functional family of macromolecules found in the extracellular matrix. Advances in our understanding of biological interactions have lead to a greater appreciation for the need to design tissue engineering scaffolds that incorporate mimetics of key extracellular matrix components. A variety of synthetic and semisynthetic molecules and polymers have been examined by tissue engineers that serve as structural, chemical and biological replacements for proteoglycans. These proteoglycan mimetics have been referred to as neoproteoglycans and serve as functional and therapeutic replacements for natural proteoglycans that are often unavailable for tissue engineering studies. Although neoproteoglycans have important limitations, such as limited signaling ability and biocompatibility, they have shown promise in replacing the natural activity of proteoglycans through cell and protein binding interactions. This review focuses on the recent in vivo and in vitro tissue engineering applications of three basic types of neoproteoglycan structures, protein–glycosaminoglycan conjugates, nano-glycosaminoglycan composites and polymer–glycosaminoglycan complexes. PMID:23399318

  12. Sensing in tissue bioreactors

    Science.gov (United States)

    Rolfe, P.

    2006-03-01

    Specialized sensing and measurement instruments are under development to aid the controlled culture of cells in bioreactors for the fabrication of biological tissues. Precisely defined physical and chemical conditions are needed for the correct culture of the many cell-tissue types now being studied, including chondrocytes (cartilage), vascular endothelial cells and smooth muscle cells (blood vessels), fibroblasts, hepatocytes (liver) and receptor neurones. Cell and tissue culture processes are dynamic and therefore, optimal control requires monitoring of the key process variables. Chemical and physical sensing is approached in this paper with the aim of enabling automatic optimal control, based on classical cell growth models, to be achieved. Non-invasive sensing is performed via the bioreactor wall, invasive sensing with probes placed inside the cell culture chamber and indirect monitoring using analysis within a shunt or a sampling chamber. Electroanalytical and photonics-based systems are described. Chemical sensing for gases, ions, metabolites, certain hormones and proteins, is under development. Spectroscopic analysis of the culture medium is used for measurement of glucose and for proteins that are markers of cell biosynthetic behaviour. Optical interrogation of cells and tissues is also investigated for structural analysis based on scatter.

  13. Effect of gamma irradiation at various temperatures and packaging conditions on chicken tissues

    International Nuclear Information System (INIS)

    Rady, A.H.; Maxwell, R.J.; Wierbicki, E.; Phillips, J.G.

    1988-01-01

    A lipid composition study on irradiated chicken muscle is reported. All muscle samples, packed either under air or vacuum, were gamma irradiated (-20 0 C) at 0, 1, 3, 6 and 10 kGy using 137 Cs (dose rate 0.1 kGy/min). Lipids were isolated from the muscle using a dry column extraction method with concomitant isolation of separated neutral and polar fractions. Lipid isolates were converted to their methyl esters and analyzed by capillary column gas chromatography with computer assisted data storage, followed by data consolidation and statistical computer analysis. Separated fatty acid profiles for neutral and polar lipids were obtained as normalized reports (each fatty acid as percentage of total fatty acids) and as gravimetric reports (mg of each fatty acid/100 g tissue). Normalized reports showed only negligible occurrence of significant changes in fatty acid profiles of neutral muscle lipid fractions regardless of irradiation doses (0 to 10 kGy) in either air and vacuum packaging. These differences were not apparent when the data were compiled as gravimetric reports. The polar lipid fractions containing the nutritionally significant ω3 and ω6 fatty acids showed only slight changes in normalized and gravimetric reports and were similarly unaffected with increasing levels of irradiation. Additionally, no new fatty acids or other artifacts due to gamma-irradiation were observed in detectable amounts by gas chromatography in any lipid fractions. (author)

  14. Degradable polymers for tissue engineering

    NARCIS (Netherlands)

    van Dijkhuizen-Radersma, Riemke; Moroni, Lorenzo; van Apeldoorn, Aart A.; Zhang, Zheng; Grijpma, Dirk W.; van Blitterswijk, Clemens A.

    2008-01-01

    This chapter elaborates the degradable polymers for tissue engineering and their required scaffold material in tissue engineering. It recognizes the examples of degradable polymers broadly used in tissue engineering. Tissue engineering is the persuasion of the body to heal itself through the

  15. AFSC/RACE/FBEP/Copeman: Effect of temperature and tissue type on fatty acid signatures of two species of North Pacific juvenile gadids: A laboratory feeding study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is from a laboratory study that investigated the effect of temperature and tissue type on fatty acid signatures of Pacific cod and walleye pollock.

  16. Reptile Soft Tissue Surgery.

    Science.gov (United States)

    Di Girolamo, Nicola; Mans, Christoph

    2016-01-01

    The surgical approach to reptiles can be challenging. Reptiles have unique physiologic, anatomic, and pathologic differences. This may result in frustrating surgical experiences. However, recent investigations provided novel, less invasive, surgical techniques. The purpose of this review was to describe the technical aspects behind soft tissue surgical techniques that have been used in reptiles, so as to provide a general guideline for veterinarians working with reptiles. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Ligament Tissue Engineering

    OpenAIRE

    Khan, Wasim Sardar

    2016-01-01

    Ligaments are commonly injured in the knee joint, and have a poor capacity for healing due to their relative avascularity. Ligament reconstruction is well established for injuries such as anterior cruciate ligament rupture, however the use of autografts and allografts for ligament reconstruction are associated with complications, and outcomes are variable. Ligament tissue engineering using stem cells, growth factors and scaffolds is a novel technique that has the potential to provide an unlim...

  18. Subcutaneous adipose tissue classification

    Directory of Open Access Journals (Sweden)

    A. Sbarbati

    2010-11-01

    Full Text Available The developments in the technologies based on the use of autologous adipose tissue attracted attention to minor depots as possible sampling areas. Some of those depots have never been studied in detail. The present study was performed on subcutaneous adipose depots sampled in different areas with the aim of explaining their morphology, particularly as far as regards stem niches. The results demonstrated that three different types of white adipose tissue (WAT can be differentiated on the basis of structural and ultrastructural features: deposit WAT (dWAT, structural WAT (sWAT and fibrous WAT (fWAT. dWAT can be found essentially in large fatty depots in the abdominal area (periumbilical. In the dWAT, cells are tightly packed and linked by a weak net of isolated collagen fibers. Collagenic components are very poor, cells are large and few blood vessels are present. The deep portion appears more fibrous then the superficial one. The microcirculation is formed by thin walled capillaries with rare stem niches. Reinforcement pericyte elements are rarely evident. The sWAT is more stromal; it is located in some areas in the limbs and in the hips. The stroma is fairly well represented, with a good vascularity and adequate staminality. Cells are wrapped by a basket of collagen fibers. The fatty depots of the knees and of the trochanteric areas have quite loose meshes. The fWAT has a noteworthy fibrous component and can be found in areas where a severe mechanic stress occurs. Adipocytes have an individual thick fibrous shell. In conclusion, the present study demonstrates evident differences among subcutaneous WAT deposits, thus suggesting that in regenerative procedures based on autologous adipose tissues the sampling area should not be randomly chosen, but it should be oriented by evidence based evaluations. The structural peculiarities of the sWAT, and particularly of its microcirculation, suggest that it could represent a privileged source for

  19. Reconstruction of the forehead acoustic properties in an Indo-Pacific humpback dolphin (Sousa chinensis), with investigation on the responses of soft tissue sound velocity to temperature.

    Science.gov (United States)

    Song, Zhongchang; Zhang, Yu; Berggren, Per; Wei, Chong

    2017-02-01

    Computed tomography (CT) imaging and ultrasound experimental measurements were combined to reconstruct the acoustic properties (density, velocity, and impedance) of the head from a deceased Indo-Pacific humpback dolphin (Sousa chinensis). The authors extracted 42 soft forehead tissue samples to estimate the sound velocity and density properties at room temperature, 25.0  °C. Hounsfield Units (HUs) of the samples were read from CT scans. Linear relationships between the tissues' HUs and velocity, and HUs and density were revealed through regression analyses. The distributions of the head acoustic properties at axial, coronal, and sagittal cross sections were reconstructed, suggesting that the forehead soft tissues were characterized by low-velocity in the melon, high-velocity in the muscle and connective tissues. Further, the sound velocities of melon, muscle, and connective tissue pieces were measured under different temperatures to investigate tissues' velocity response to temperature. The results demonstrated nonlinear relationships between tissues' sound velocity and temperature. This study represents a first attempt to provide general information on acoustic properties of this species. The results could provide meaningful information for understanding the species' bioacoustic characteristics and for further investigation on sound beam formation of the dolphin.

  20. The plant tissue culture

    International Nuclear Information System (INIS)

    Crocomo, O.J.; Sharp, W.R.

    1973-01-01

    Progress in the field of plant tissue culture at the Plant Biochemistry Sector, Centro de Energia na Agricultura (CENA), Piracicaba, S.P., Brazil, pertains to the simplification of development in 'Phaseolus vulgaris' by dividing the organism into its component organs, tissues, and cells and the maintenance of these components on defined culture media 'in vitro'. This achievement has set the stage for probing the basis for the stability of the differentiated states and/or the reentry of mature differentiated cells into the mitotic cell cycle and their subsequent redifferentiation. Data from such studies at the cytological and biochemical level have been invaluable in the elucidation of the control mechanisms responsible for expression of the cellular phenotype. Unlimited possibilities exist for the application of tissue culture in the vegetative propagation of 'Phaseolus' and other important cultivars in providing genocopies or a large scale and/or readily obtaining plantlets from haploid cell lines or from protoplast (wall-less cells) hybridization products following genetic manipulation. These tools are being applied in this laboratory for the development and selection of high protein synthesizing 'Phaseolus' cultivars

  1. Cardiac tissue engineering

    Directory of Open Access Journals (Sweden)

    MILICA RADISIC

    2005-03-01

    Full Text Available We hypothesized that clinically sized (1-5 mm thick,compact cardiac constructs containing physiologically high density of viable cells (~108 cells/cm3 can be engineered in vitro by using biomimetic culture systems capable of providing oxygen transport and electrical stimulation, designed to mimic those in native heart. This hypothesis was tested by culturing rat heart cells on polymer scaffolds, either with perfusion of culture medium (physiologic interstitial velocity, supplementation of perfluorocarbons, or with electrical stimulation (continuous application of biphasic pulses, 2 ms, 5 V, 1 Hz. Tissue constructs cultured without perfusion or electrical stimulation served as controls. Medium perfusion and addition of perfluorocarbons resulted in compact, thick constructs containing physiologic density of viable, electromechanically coupled cells, in contrast to control constructs which had only a ~100 mm thick peripheral region with functionally connected cells. Electrical stimulation of cultured constructs resulted in markedly improved contractile properties, increased amounts of cardiac proteins, and remarkably well developed ultrastructure (similar to that of native heart as compared to non-stimulated controls. We discuss here the state of the art of cardiac tissue engineering, in light of the biomimetic approach that reproduces in vitro some of the conditions present during normal tissue development.

  2. Atomically resolved tissue integration.

    Science.gov (United States)

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

    2014-08-13

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

  3. Necrotizing Soft Tissue Infection

    Directory of Open Access Journals (Sweden)

    Sahil Aggarwal, BS

    2018-04-01

    Full Text Available History of present illness: A 71-year-old woman with a history of metastatic ovarian cancer presented with sudden onset, rapidly progressing painful rash in the genital region and lower abdominal wall. She was febrile to 103°F, heart rate was 114 beats per minute, and respiratory rate was 24 per minute. Her exam was notable for a toxic-appearing female with extensive areas of erythema, tenderness, and induration to her lower abdomen, intertriginous areas, and perineum with intermittent segments of crepitus without hemorrhagic bullae or skin breakdown. Significant findings: Computed tomography (CT of the abdominal and pelvis with intravenous (IV contrast revealed inflammatory changes, including gas and fluid collections within the ventral abdominal wall extending to the vulva, consistent with a necrotizing soft tissue infection. Discussion: Necrotizing fasciitis is a serious infection of the skin and soft tissues that requires an early diagnosis to reduce morbidity and mortality. Classified into several subtypes based on the type of microbial infection, necrotizing fasciitis can rapidly progress to septic shock or death if left untreated.1 Diagnosing necrotizing fasciitis requires a high index of suspicion based on patient risk factors, presentation, and exam findings. Definitive treatment involves prompt surgical exploration and debridement coupled with IV antibiotics.2,3 Clinical characteristics such as swelling, disproportionate pain, erythema, crepitus, and necrotic tissue should be a guide to further diagnostic tests.4 Unfortunately, lab values such as white blood cell count and lactate imaging studies have high sensitivity but low specificity, making the diagnosis of necrotizing fasciitis still largely a clinical one.4,5 CT is a reliable method to exclude the diagnosis of necrotizing soft tissue infections (sensitivity of 100%, but is only moderately reliable in correctly identifying such infections (specificity of 81%.5 Given the emergent

  4. Biomaterials for tissue engineering applications.

    Science.gov (United States)

    Keane, Timothy J; Badylak, Stephen F

    2014-06-01

    With advancements in biological and engineering sciences, the definition of an ideal biomaterial has evolved over the past 50 years from a substance that is inert to one that has select bioinductive properties and integrates well with adjacent host tissue. Biomaterials are a fundamental component of tissue engineering, which aims to replace diseased, damaged, or missing tissue with reconstructed functional tissue. Most biomaterials are less than satisfactory for pediatric patients because the scaffold must adapt to the growth and development of the surrounding tissues and organs over time. The pediatric community, therefore, provides a distinct challenge for the tissue engineering community. Copyright © 2014. Published by Elsevier Inc.

  5. Pharmacokinetics and tissue behavior of enrofloxacin and its metabolite ciprofloxacin in turbot Scophthalmus maximus at two water temperatures

    Science.gov (United States)

    Liang, Junping; Li, Jian; Zhao, Fazhen; Liu, Ping; Chang, Zhiqiang

    2012-07-01

    Turbot Scophthalmus maximus, an important aquaculture species in China, currently suffers from epizootic diseases because of high density aquaculture. Enrofloxacin has been used to treat various systemic bacterial fish infections. However, studies concerning the pharmacokinetics of enrofloxacin in turbot are limited. In this study, the pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin, were investigated in the turbot following intravenous and oral administration at 10 mg enrofloxacin/kg body weight, at 16°C and 10°C water temperatures. The concentrations of enrofloxacin and ciprofloxacin in the main tissues (plasma, muscle, liver and kidney) were detected by HPLC. The results show that the plasma concentration-time data for enrofloxacin were best described as a two-compartment open model after intravenous and oral administration. Three pharmacokinetic equations were established between the concentrations and temperatures. The kinetic profile of enrofloxacin was temperature dependent. The absorption half-life of enrofloxacin was 1.99 h and 2.17 h after oral administration, whereas the elimination half-life of the drug was 98.63 h and 136.59 h at 16°C and 10°C, respectively. The peak concentration of enrofloxacin in plasma and tissues was higher at 16°C than that at 10°C, and the peak plasma concentration time in the liver was the shortest at both temperatures among those of other tissues. The plasma C max /MIC ratio varied between 11.08 and 5 540.00 at 16°C; and between 7.92 and 3 960.00 at 10°C. The AUC/MIC ratio was 467.82-280 690.00 at 16°C, and 359.48-215 690.00 at 10°C. These ratios indicate that it is possible to obtain therapeutic efficacy. Very low levels of ciprofloxacin were detected. The AUC ratios of ciprofloxacin and enrofloxacin in plasma suggest that plasma ciprofloxacin might play a minor role in enrofloxacin treatment for turbot.

  6. Soft tissue sparganosis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ki Soon; Lee, Yul; Chung, Soo Young; Park, Choong Ki; Lee, Kwan Sup [Hallym University College of Medicine, Seoul (Korea, Republic of); Cho, In Hwan; Suh, Hyoung Sim [Daelin S. Mary' s Hospital, Seoul (Korea, Republic of)

    1993-11-15

    Sparganosis is a rare tissue-parasitic infestation caused by a plerocercoid tapeworm larva(sparganum), genus Spirometra. The most common clinical presentation of sparganosis is a palpable subcutaneous mass or masses. Fifteen simple radiographs and 10 ultrasosnograms of 17 patients with operatively verified subcutaneous sparganosis were retrospectively analyzed to find its radiologic characteristics for preoperative diagnosis of sparganosis. The location of the subcutaneous sparganosis were lower extremity, abdominal wall, breast, inguinal region and scrotum in order of frequency. The simple radiographs showed linear or elongated calcification with or without nodular elongated shaped soft tissue mass shadows in 8 patients, soft tissue mass shadow only in 2 patients and lateral abdominal wall thickening in 1 patient. But no specific findings was noted in 4 patients with small abdominal and inguinal masses. We could classify the subcutaneous sparganosis by ultrasound into 2 types: one is long band-like hypoechoic structures, corresponding to the subcutaneous tunnel-like tracks formed by migration of sparganum larva and the order is elongated or ovoid hyperechoic nodules, representing granulomas. Long band-like hypoechoic structures within or associated with mixed echoic granulomatous masses were noted in 6 patients and elongated or ovoid hypoechoic mass or masses were noted in 4 patients. In conclusion, sparganosis should be considered when these radiologic findings-irregular linear calcifications on simple radiograph and long band-like hypoechoic structures on ultrasonography, corresponding to the subcutaneous tunnel-like tracks formed by migration of sparganum larva are noted in the patients who have subcutaneous palpable mass or masses. And radiologic examination especially ultrasonography is very helpful to diagnose sparganosis.

  7. [Human brown adipose tissue].

    Science.gov (United States)

    Virtanen, Kirsi A; Nuutila, Pirjo

    2015-01-01

    Adult humans have heat-producing and energy-consuming brown adipose tissue in the clavicular region of the neck. There are two types of brown adipose cells, the so-called classic and beige adipose cells. Brown adipose cells produce heat by means of uncoupler protein 1 (UCP1) from fatty acids and sugar. By applying positron emission tomography (PET) measuring the utilization of sugar, the metabolism of brown fat has been shown to multiply in the cold, presumably influencing energy consumption. Active brown fat is most likely present in young adults, persons of normal weight and women, least likely in obese persons.

  8. Microsurgical Composite Tissue Transplantation

    Science.gov (United States)

    Serafin, Donald; Georgiade, Nicholas G.

    1978-01-01

    Since 1974, 69 patients with extensive defects have undergone reconstruction by microsurgical composite tissue transplantation. Using this method, donor composite tissue is isolated on its blood supply, removed to a distant recipient site, and the continuity of blood flow re-established by microvascular anastomoses. In this series, 56 patients (81%) were completely successful. There have been eight (12%) failures, primarily in the extremities. There have been five (7%) partial successes, (i.e., a microvascular flap in which a portion was lost requiring a secondary procedure such as a split thickness graft). In those patients with a severely injured lower extremity, the failure rate was the greatest. Most of these were arterial (six of seven). These failures occurred early in the series and were thought to be related to a severely damaged recipient vasculature. This problem has been circumvented by an autogenous interpositional vein graft, permitting more mobility of flap placement. In the upper extremity, all but one case were successful. Early motion was permitted, preventing joint capsular contractures and loss of function. Twenty-three cases in the head and neck region were successful (one partial success). This included two composite rib grafts to the mandible. Prolonged delays in reconstruction following extirpation of a malignancy were avoided. A rapid return to society following complete reconstruction was ensured. Nine patients presented for reconstruction of the breast and thorax following radical mastectomy. All were successfully reconstructed with this new technique except one patient. Its many advantages include immediate reconstruction without delayed procedures and no secondary deformity of the donor site. Healthy, well vascularized tissue can now be transferred to a previously irradiated area with no tissue loss. This new method offers many advantages to older methods of reconstruction. Length of hospital stay and immobilization are reduced. The

  9. Butyltin Compounds in Tissues.

    Science.gov (United States)

    1986-01-01

    accumulate tin in their tissues (Dooley & Homer. 1983). Whether the toxic tributyltin (Bu 3 Sn) is accumulated as such or whether the various marine organisms...did not appear to have reached an equilibrium after 60 days of exposure: while fish appeared to be able to deal with tributyltin fairly efficiently...Depuration of tributyltin in oysters occurred at 5 percent/day to give a calculated half-life of about 2 weeks. AcO51.on. For I;, + I - INSPECTED~ is

  10. Soft tissue anchor systems.

    Science.gov (United States)

    Yu, G V; Chang, T; White, J M

    1994-04-01

    The concept of soft tissue attachment and reattachment has been addressed over the years through a variety of surgical techniques. This includes tendons and ligaments that have been detached both surgically and traumatically from their osseous origins or insertions. This study is designed to provide the reader with a comprehensive overview of current commercially available devices. Detailed descriptions of the various devices are provided along with a discussion of the advantages and disadvantages of each. Their application and use in reconstructive foot and ankle surgery are also discussed.

  11. Tissue bank: Sri Lanka

    International Nuclear Information System (INIS)

    2003-01-01

    Human degenerative diseases and congenital defects are common throughout the world. Many people suffer also from burns, fractures and nerve damage resulting from traumatic accidents and outbreaks of violence which occur all too frequently, especially in poorer countries. Far too many people are impaired for life because they have no access to treatment or simply cannot afford it. The Department of Technical Co-operation is sponsoring a programme, with technical support from the Division of Nuclear Medicine, to improve facilities at the Sri Lanka Tissue Bank. (IAEA)

  12. Heritable Disorders of Connective Tissue

    Science.gov (United States)

    ... Home Health Topics English Español Heritable Disorders of Connective Tissue Basics In-Depth Download Download EPUB Download PDF ... they? Points To Remember About Heritable Disorders of Connective Tissue There are more than 200 heritable disorders that ...

  13. Random lasing in human tissues

    International Nuclear Information System (INIS)

    Polson, Randal C.; Vardeny, Z. Valy

    2004-01-01

    A random collection of scatterers in a gain medium can produce coherent laser emission lines dubbed 'random lasing'. We show that biological tissues, including human tissues, can support coherent random lasing when infiltrated with a concentrated laser dye solution. To extract a typical random resonator size within the tissue we average the power Fourier transform of random laser spectra collected from many excitation locations in the tissue; we verified this procedure by a computer simulation. Surprisingly, we found that malignant tissues show many more laser lines compared to healthy tissues taken from the same organ. Consequently, the obtained typical random resonator was found to be different for healthy and cancerous tissues, and this may lead to a technique for separating malignant from healthy tissues for diagnostic imaging

  14. Food restriction attenuates oxidative stress in brown adipose tissue of striped hamsters acclimated to a warm temperature.

    Science.gov (United States)

    Zhang, Ji-Ying; Zhao, Xiao-Ya; Wang, Gui-Ying; Wang, Chun-Ming; Zhao, Zhi-Jun

    2016-05-01

    It has been suggested that the up-regulation of uncoupling proteins (UCPs) decreases reactive oxygen species (ROS) production, in which case there should be a negative relationship between UCPs expression and ROS levels. In this study, the effects of temperature and food restriction on ROS levels and metabolic rate, UCP1 mRNA expression and antioxidant levels were examined in the brown adipose tissue (BAT) of the striped hamsters (Cricetulus barabensis). The metabolic rate and food intake of hamsters which had been restricted to 80% of ad libitum food intake, and acclimated to a warm temperature (30°C), decreased significantly compared to a control group. Hydrogen peroxide (H2O2) levels were 42.9% lower in food restricted hamsters than in the control. Malonadialdehyde (MDA) levels of hamsters acclimated to 30°C that were fed ad libitum were significantly higher than those of the control group, but 60.1% lower than hamsters that had been acclimated to the same temperature but subject to food restriction. There were significantly positive correlations between H2O2 and, MDA levels, catalase activity, and total antioxidant capacity. Cytochrome c oxidase activity and UCP1 mRNA expression significantly decreased in food restricted hamsters compared to the control. These results suggest that warmer temperatures increase oxidative stress in BAT by causing the down-regulation of UCP1 expression and decreased antioxidant activity, but food restriction may attenuate the effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Temperature simulations in hyperthermia treatment planning of the head and neck region. Rigorous optimization of tissue properties

    Energy Technology Data Exchange (ETDEWEB)

    Verhaart, Rene F.; Rijnen, Zef; Verduijn, Gerda M.; Paulides, Margarethus M. [Erasmus MC - Cancer Institute, Department of Radiation Oncology, Hyperthermia Unit, Rotterdam (Netherlands); Fortunati, Valerio; Walsum, Theo van; Veenland, Jifke F. [Erasmus MC, Departments of Medical Informatics and Radiology, Biomedical Imaging Group Rotterdam, Rotterdam (Netherlands)

    2014-12-15

    Hyperthermia treatment planning (HTP) is used in the head and neck region (H and N) for pretreatment optimization, decision making, and real-time HTP-guided adaptive application of hyperthermia. In current clinical practice, HTP is based on power-absorption predictions, but thermal dose-effect relationships advocate its extension to temperature predictions. Exploitation of temperature simulations requires region- and temperature-specific thermal tissue properties due to the strong thermoregulatory response of H and N tissues. The purpose of our work was to develop a technique for patient group-specific optimization of thermal tissue properties based on invasively measured temperatures, and to evaluate the accuracy achievable. Data from 17 treated patients were used to optimize the perfusion and thermal conductivity values for the Pennes bioheat equation-based thermal model. A leave-one-out approach was applied to accurately assess the difference between measured and simulated temperature (∇T). The improvement in ∇T for optimized thermal property values was assessed by comparison with the ∇T for values from the literature, i.e., baseline and under thermal stress. The optimized perfusion and conductivity values of tumor, muscle, and fat led to an improvement in simulation accuracy (∇T: 2.1 ± 1.2 C) compared with the accuracy for baseline (∇T: 12.7 ± 11.1 C) or thermal stress (∇T: 4.4 ± 3.5 C) property values. The presented technique leads to patient group-specific temperature property values that effectively improve simulation accuracy for the challenging H and N region, thereby making simulations an elegant addition to invasive measurements. The rigorous leave-one-out assessment indicates that improvements in accuracy are required to rely only on temperature-based HTP in the clinic. (orig.) [German] Die Hyperthermiebehandlungsplanung (HTP, ''hyperthermia treatment planning'') wird in der Kopf- und Halsregion zur Optimierung der

  16. Neutron RBE for normal tissues

    International Nuclear Information System (INIS)

    Field, S.B.; Hornsey, S.

    1979-01-01

    RBE for various normal tissues is considered as a function of neutron dose per fraction. Results from a variety of centres are reviewed. It is shown that RBE is dependent on neutron energy and is tissue dependent, but is not specially high for the more critical tissues or for damage occurring late after irradiation. (author)

  17. Repair kinetics in tissues

    International Nuclear Information System (INIS)

    Thames, H.D.

    1989-01-01

    Monoexponential repair kinetics is based on the assumption of a single, dose-independent rate of repair of sublethal injury in the target cells for tissue injury after exposure to ionizing radiation. Descriptions of the available data based on this assumption have proved fairly successful for both acutely responding (skin, lip mucosa, gut) and late-responding (lung, spinal cord) normal tissues. There are indications of biphasic exponential repair in both categories, however. Unfortunately, the data usually lack sufficient resolution to permit unambiguous determination of the repair rates. There are also indications that repair kinetics may depend on the size of the dose. The data are conflicting on this account, however, with suggestions of both faster and slower repair after larger doses. Indeed, experiments that have been explicitly designed to test this hypothesis show either no effect (gut, spinal cord), faster repair after higher doses (lung, kidney), or slower repair after higher doses (skin). Monoexponential repair appears to be a fairly accurate description that provides an approximation to a more complicated picture, the elucidation of whose details will, however, require very careful and extensive experimental study. (author). 30 refs.; 1 fig

  18. Peripheral tissue oximetry

    DEFF Research Database (Denmark)

    Hyttel-Sorensen, Simon; Hessel, Trine Witzner; Greisen, Gorm

    2014-01-01

    Estimation of regional tissue oxygenation (rStO2) by near infrared spectroscopy enables non-invasive end-organ oxygen balance monitoring and could be a valuable tool in intensive care. However, the diverse absolute values and dynamics of different devices, and overall poor repeatability of measur......Estimation of regional tissue oxygenation (rStO2) by near infrared spectroscopy enables non-invasive end-organ oxygen balance monitoring and could be a valuable tool in intensive care. However, the diverse absolute values and dynamics of different devices, and overall poor repeatability......, and response to changing oxygenation by the down slope of rStO2 during vascular occlusion in the respective arm. 10 healthy adults, 21-29 years old, with double skinfolds on the forearm less than 10 mm participated. The median rStO2 was 70.7% (interquartile range (IQR) 7.7%), 68.4% (IQR 8.4%), and 64.6% (IQR 4...

  19. Localization of IAA transporting tissue by tissue printing and autoradiography

    International Nuclear Information System (INIS)

    Mee-Rye Cha; Evans, M.L.; Hangarter, R.P.

    1991-01-01

    Tissue printing on nitrocellulose membranes provides a useful technique for visualizing anatomical details of tissue morphology of cut ends of stem segments. Basal ends of Coleus stem and corn coleoptile segments that were transporting 14 C-IAA were gently blotted onto DEAE-nitrocellulose for several minutes to allow 14 C-IAA to efflux from the tissue. Because of the anion exchange properties of DEAE-nitrocellulose the 14 C-IAA remains on the membrane at the point it leaves the transporting tissue. Autoradiography of the DEAE membrane allowed indirect visualization of the tissues preferentially involved in auxin transport. The authors observed that polar transport through the stem segments occurred primarily through or in association with vascular tissues. However, in Coleus stems, substantial amounts of the label appeared to move through the tissue by diffusion as well as by active transport

  20. Ratiometric Afterglow Nanothermometer for Simultaneous in Situ Bioimaging and Local Tissue Temperature Sensing

    NARCIS (Netherlands)

    Yang, J.; Liu, Y.; Zhao, Y.; Gong, Z.; Zhang, M.; Yan, D.; Zhu, H.; Liu, C.; Xu, C.; Zhang, H.

    2017-01-01

    Simultaneous in situ bioimage tracing and temperature sensing have been two of the foci of modern biomedicine that have given birth to designing novel luminescent nanothermometers with dual functions. To minimize the disadvantages of existing approaches, like the surface effect of nanoparticles,

  1. Relationship between meat toughness and properties of connective tissue from cows and young bulls heat treated at low temperatures for prolonged times

    DEFF Research Database (Denmark)

    Christensen, Line; Ertbjerg, Per; Løje, Hanne

    2013-01-01

    of beef was investigated and the relationship to properties of connective tissue was examined. Measurements of toughness, collagen solubility, cathepsin activity and protein denaturation of beef semitendinosus heated at temperatures between 53. °C and 63. °C for up to 19 1/2. h were conducted. The results...... of the connective tissue, caused partly by denaturation or conformational changes of the proteins and/or by solubilization of collagen. © 2012 Elsevier Ltd....

  2. One-Step Preservation of Phosphoproteins and Tissue Morphology at Room Temperature for Diagnostic and Research Specimens

    Science.gov (United States)

    Mueller, Claudius; Edmiston, Kirsten H.; Carpenter, Calvin; Gaffney, Eoin; Ryan, Ciara; Ward, Ronan; White, Susan; Memeo, Lorenzo; Colarossi, Cristina; Petricoin, Emanuel F.; Liotta, Lance A.; Espina, Virginia

    2011-01-01

    Background There is an urgent need to measure phosphorylated cell signaling proteins in cancer tissue for the individualization of molecular targeted kinase inhibitor therapy. However, phosphoproteins fluctuate rapidly following tissue procurement. Snap-freezing preserves phosphoproteins, but is unavailable in most clinics and compromises diagnostic morphology. Formalin fixation preserves tissue histomorphology, but penetrates tissue slowly, and is unsuitable for stabilizing phosphoproteins. We originated and evaluated a novel one-step biomarker and histology preservative (BHP) chemistry that stabilizes signaling protein phosphorylation and retains formalin-like tissue histomorphology with equivalent immunohistochemistry in a single paraffin block. Results Total protein yield extracted from BHP-fixed, routine paraffin-embedded mouse liver was 100% compared to snap-frozen tissue. The abundance of 14 phosphorylated proteins was found to be stable over extended fixation times in BHP fixed paraffin embedded human colon mucosa. Compared to matched snap-frozen tissue, 8 phosphoproteins were equally preserved in mouse liver, while AMPKβ1 Ser108 was slightly elevated after BHP fixation. More than 25 tissues from mouse, cat and human specimens were evaluated for preservation of histomorphology. Selected tissues were evaluated in a multi-site, independent pathology review. Tissue fixed with BHP showed equivalent preservation of cytoplasmic and membrane cytomorphology, with significantly better nuclear chromatin preservation by BHP compared to formalin. Immunohistochemical staining of 13 non-phosphorylated proteins, including estrogen receptor alpha, progesterone receptor, Ki-67 and Her2, was equal to or stronger in BHP compared to formalin. BHP demonstrated significantly improved immunohistochemical detection of phosphorylated proteins ERK Thr202/Tyr204, GSK3-α/β Ser21/Ser9, p38-MAPK Thr180/Tyr182, eIF4G Ser1108 and Acetyl-CoA Carboxylase Ser79. Conclusion In a single

  3. One-step preservation of phosphoproteins and tissue morphology at room temperature for diagnostic and research specimens.

    Directory of Open Access Journals (Sweden)

    Claudius Mueller

    Full Text Available BACKGROUND: There is an urgent need to measure phosphorylated cell signaling proteins in cancer tissue for the individualization of molecular targeted kinase inhibitor therapy. However, phosphoproteins fluctuate rapidly following tissue procurement. Snap-freezing preserves phosphoproteins, but is unavailable in most clinics and compromises diagnostic morphology. Formalin fixation preserves tissue histomorphology, but penetrates tissue slowly, and is unsuitable for stabilizing phosphoproteins. We originated and evaluated a novel one-step biomarker and histology preservative (BHP chemistry that stabilizes signaling protein phosphorylation and retains formalin-like tissue histomorphology with equivalent immunohistochemistry in a single paraffin block. RESULTS: Total protein yield extracted from BHP-fixed, routine paraffin-embedded mouse liver was 100% compared to snap-frozen tissue. The abundance of 14 phosphorylated proteins was found to be stable over extended fixation times in BHP fixed paraffin embedded human colon mucosa. Compared to matched snap-frozen tissue, 8 phosphoproteins were equally preserved in mouse liver, while AMPKβ1 Ser108 was slightly elevated after BHP fixation. More than 25 tissues from mouse, cat and human specimens were evaluated for preservation of histomorphology. Selected tissues were evaluated in a multi-site, independent pathology review. Tissue fixed with BHP showed equivalent preservation of cytoplasmic and membrane cytomorphology, with significantly better nuclear chromatin preservation by BHP compared to formalin. Immunohistochemical staining of 13 non-phosphorylated proteins, including estrogen receptor alpha, progesterone receptor, Ki-67 and Her2, was equal to or stronger in BHP compared to formalin. BHP demonstrated significantly improved immunohistochemical detection of phosphorylated proteins ERK Thr202/Tyr204, GSK3-α/β Ser21/Ser9, p38-MAPK Thr180/Tyr182, eIF4G Ser1108 and Acetyl-CoA Carboxylase Ser79

  4. Photothermal effects of laser tissue soldering

    International Nuclear Information System (INIS)

    McNally, K.M.; Sorg, B.S.; Welch, A.J.; Dawes, J.M.; Owen, E.R.

    1999-01-01

    Low-strength anastomoses and thermal damage of tissue are major concerns in laser tissue welding techniques where laser energy is used to induce thermal changes in the molecular structure of the tissues being joined, hence allowing them to bond together. Laser tissue soldering, on the other hand, is a bonding technique in which a protein solder is applied to the tissue surfaces to be joined, and laser energy is used to bond the solder to the tissue surfaces. The addition of protein solders to augment tissue repair procedures significantly reduces the problems of low strength and thermal damage associated with laser tissue welding techniques. Investigations were conducted to determine optimal solder and laser parameters for tissue repair in terms of tensile strength, temperature rise and damage and the microscopic nature of the bonds formed. An in vitro study was performed using an 808 nm diode laser in conjunction with indocyanine green (ICG)-doped albumin protein solders to repair bovine aorta specimens. Liquid and solid protein solders prepared from 25% and 60% bovine serum albumin (BSA), respectively, were compared. The efficacy of temperature feedback control in enhancing the soldering process was also investigated. Increasing the BSA concentration from 25% to 60% greatly increased the tensile strength of the repairs. A reduction in dye concentration from 2.5mgml -1 to 0.25mgml -1 was also found to result in an increase in tensile strength. Increasing the laser irradiance and thus surface temperature resulted in an increased severity of histological injury. Thermal denaturation of tissue collagen and necrosis of the intimal layer smooth muscle cells increased laterally and in depth with higher temperatures. The strongest repairs were produced with an irradiance of 6.4Wcm -2 using a solid protein solder composed of 60% BSA and 0.25mgml -1 ICG. Using this combination of laser and solder parameters, surface temperatures were observed to reach 85±5 deg. C with a

  5. Fabricating a pearl/PLGA composite scaffold by the low-temperature deposition manufacturing technique for bone tissue engineering

    International Nuclear Information System (INIS)

    Xu Mingen; Li Yanlei; Suo Hairui; Wang Qiujun; Ge Yakun; Xu Ying; Yan Yongnian; Liu Li

    2010-01-01

    Here we developed a composite scaffold of pearl/poly(lactic-co-glycolic acid) (pearl/PLGA) utilizing the low-temperature deposition manufacturing (LDM). LDM makes it possible to fabricate scaffolds with designed microstructure and macrostructure, while keeping the bioactivity of biomaterials by working at a low temperature. Process optimization was carried out to fabricate a mixture of pearl powder, PLGA and 1,4-dioxane with the designed hierarchical structures, and freeze-dried at a temperature of -40 deg. C. Scaffolds with square and designated bone shape were fabricated by following the 3D model. Marrow stem cells (MSCs) were seeded on the pearl/PLGA scaffold and then cultured in a rotating cell culture system. The adhesion, proliferation and differentiation of MSCs into osteoblasts were determined using scanning electronic microscopy, WST-1 assay, alkaline phosphatase activity assay, immunofluorescence staining and real-time reverse transcription polymerase chain reaction. The results showed that the composite scaffold had high porosity (81.98 ± 3.75%), proper pore size (micropores: <10 μm; macropore: 495 ± 54 μm) and mechanical property (compressive strength: 0.81 ± 0.04 MPa; elastic modulus: 23.14 ± 0.75 MPa). The pearl/PLGA scaffolds exhibited better biocompatibility and osteoconductivity compared with the tricalcium phosphate/PLGA scaffold. All these results indicate that the pearl/PLGA scaffolds fulfill the basic requirements of bone tissue engineering scaffold.

  6. Tissue engineered tumor models.

    Science.gov (United States)

    Ingram, M; Techy, G B; Ward, B R; Imam, S A; Atkinson, R; Ho, H; Taylor, C R

    2010-08-01

    Many research programs use well-characterized tumor cell lines as tumor models for in vitro studies. Because tumor cells grown as three-dimensional (3-D) structures have been shown to behave more like tumors in vivo than do cells growing in monolayer culture, a growing number of investigators now use tumor cell spheroids as models. Single cell type spheroids, however, do not model the stromal-epithelial interactions that have an important role in controlling tumor growth and development in vivo. We describe here a method for generating, reproducibly, more realistic 3-D tumor models that contain both stromal and malignant epithelial cells with an architecture that closely resembles that of tumor microlesions in vivo. Because they are so tissue-like we refer to them as tumor histoids. They can be generated reproducibly in substantial quantities. The bioreactor developed to generate histoid constructs is described and illustrated. It accommodates disposable culture chambers that have filled volumes of either 10 or 64 ml, each culture yielding on the order of 100 or 600 histoid particles, respectively. Each particle is a few tenths of a millimeter in diameter. Examples of histological sections of tumor histoids representing cancers of breast, prostate, colon, pancreas and urinary bladder are presented. Potential applications of tumor histoids include, but are not limited to, use as surrogate tumors for pre-screening anti-solid tumor pharmaceutical agents, as reference specimens for immunostaining in the surgical pathology laboratory and use in studies of invasive properties of cells or other aspects of tumor development and progression. Histoids containing nonmalignant cells also may have potential as "seeds" in tissue engineering. For drug testing, histoids probably will have to meet certain criteria of size and tumor cell content. Using a COPAS Plus flow cytometer, histoids containing fluorescent tumor cells were analyzed successfully and sorted using such criteria.

  7. Effects of storage temperature on the quantity and integrity of genomic DNA extracted from mice tissues: A comparison of recovery methods

    Directory of Open Access Journals (Sweden)

    Huda H. Al-Griw

    2017-08-01

    Full Text Available Efficient extraction of genomic DNA (gDNA from biological materials found in harsh environments is the first step for successful forensic DNA profiling. This study aimed to evaluate two methods for DNA recovery from animal tissues (livers, muscles, focusing on the best storage temperature for DNA yield in term of quality, quantity, and integrity for use in several downstream molecular techniques. Six male Swiss albino mice were sacrificed, liver and muscle tissues (n=32 were then harvested and stored for one week in different temperatures, -20C, 4C, 25C and 40C. The conditioned animal tissues were used for DNA extraction by Chelex-100 method or NucleoSpin Blood and Tissue kit. The extracted gDNA was visualized on 1.5% agarose gel electrophoresis to determine the quality of gDNA and analysed spectrophotometrically to determine the DNA concentration and the purity. Both methods, Chelex-100 and NucleoSpin Blood and Tissue kit found to be appropriate for yielding high quantity of gDNA, with the Chelex100 method yielding a greater quantity (P < 0.045 than the kit. At -20C, 4C, and 25C temperatures, the concentration of DNA yield was numerically lower than at 40C. The NucleoSpin Blood and Tissue kit produced a higher (P=0.031 purity product than the Chelex-100 method, particularly for muscle tissues. The Chelex-100 method is cheap, fast, effective, and is a crucial tool for yielding DNA from animal tissues (livers, muscles exposed to harsh environment with little limitations.

  8. Computed estimates of maximum temperature elevations in fetal tissues during transabdominal pulsed Doppler examinations.

    Science.gov (United States)

    Bly, S H; Vlahovich, S; Mabee, P R; Hussey, R G

    1992-01-01

    Measured characteristics of ultrasonic fields were obtained in submissions from manufacturers of diagnostic ultrasound equipment for devices operating in pulsed Doppler mode. Simple formulae were used with these data to generate upper limits to fetal temperature elevations, delta Tlim, during a transabdominal pulsed Doppler examination. A total of 236 items were analyzed, each item being a console/transducer/operating-mode/intended-use combination, for which the spatial-peak temporal-average intensity, ISPTA, was greater than 500 mW cm-2. The largest calculated delta Tlim values were approximately 1.5, 7.1 and 8.7 degrees C for first-, second- and third-trimester examinations, respectively. The vast majority of items yielded delta Tlim values which were less than 1 degree C in the first trimester. For second- and third-trimester examinations, where heating of fetal bone determines delta Tlim, most delta Tlim values were less than 4 degrees C. The clinical significance of the results is discussed.

  9. Microscopic characterization of collagen modifications induced by low-temperature diode-laser welding of corneal tissue.

    Science.gov (United States)

    Matteini, Paolo; Rossi, Francesca; Menabuoni, Luca; Pini, Roberto

    2007-08-01

    Laser welding of corneal tissue that employs diode lasers (810 nm) at low power densities (12-20 W/cm(2)) in association with Indocyanine Green staining of the wound is a technique proposed as an alternative to conventional suturing procedures. The aim of this study is to evaluate, by means of light (LM) and transmission electron microscopy (TEM) analyses, the structural modifications induced in laser-welded corneal stroma. Experiments were carried out in 20 freshly enucleated pig eyes. A 3.5 mm in length full-thickness cut was produced in the cornea, and was then closed by laser welding. Birefringence modifications in samples stained with picrosirius red dye were analyzed by polarized LM to assess heat damage. TEM analysis was performed on ultra-thin slices, contrasted with uranyl acetate and lead citrate, in order to assess organization and size of type I collagen fibrils after laser welding. LM evidenced bridges of collagen bundles between the wound edges, with a loss of regular lamellar organization at the welded site. Polarized LM indicated that birefringence properties were mostly preserved after laser treatment. TEM examinations revealed the presence of quasi-ordered groups of fibrils across the wound edges preserving their interfibrillar spacing. These fibrils appeared morphologically comparable to those in the control tissue, indicating that type I collagen was not denatured during the diode laser corneal welding. The preservation of substantially intact, undenatured collagen fibrils in laser-welded corneal wounds supported the thermodynamic studies that we carried out recently, which indicated temperatures below 66 degrees C at the weld site under laser irradiation. This observation enabled us to hypothesize that the mechanism, proposed in the literature, of unwinding of collagen triple helixes followed by fibrils "interdigitation" is not likely to occur in the welding process that we set up for the corneal suturing.

  10. Flocking transitions in confluent tissues.

    Science.gov (United States)

    Giavazzi, Fabio; Paoluzzi, Matteo; Macchi, Marta; Bi, Dapeng; Scita, Giorgio; Manning, M Lisa; Cerbino, Roberto; Marchetti, M Cristina

    2018-04-25

    Collective cell migration in dense tissues underlies important biological processes, such as embryonic development, wound healing and cancer invasion. While many aspects of single cell movements are now well established, the mechanisms leading to displacements of cohesive cell groups are still poorly understood. To elucidate the emergence of collective migration in mechanosensitive cells, we examine a self-propelled Voronoi (SPV) model of confluent tissues with an orientational feedback that aligns a cell's polarization with its local migration velocity. While shape and motility are known to regulate a density-independent liquid-solid transition in tissues, we find that aligning interactions facilitate collective motion and promote solidification, with transitions that can be predicted by extending statistical physics tools such as effective temperature to this far-from-equilibrium system. In addition to accounting for recent experimental observations obtained with epithelial monolayers, our model predicts structural and dynamical signatures of flocking, which may serve as gateway to a more quantitative characterization of collective motility.

  11. Effect of variable heat transfer coefficient on tissue temperature next to a large vessel during radiofrequency tumor ablation

    Directory of Open Access Journals (Sweden)

    Pinheiro Cleber

    2008-07-01

    Full Text Available Abstract Background One of the current shortcomings of radiofrequency (RF tumor ablation is its limited performance in regions close to large blood vessels, resulting in high recurrence rates at these locations. Computer models have been used to determine tissue temperatures during tumor ablation procedures. To simulate large vessels, either constant wall temperature or constant convective heat transfer coefficient (h have been assumed at the vessel surface to simulate convection. However, the actual distribution of the temperature on the vessel wall is non-uniform and time-varying, and this feature makes the convective coefficient variable. Methods This paper presents a realistic time-varying model in which h is a function of the temperature distribution at the vessel wall. The finite-element method (FEM was employed in order to model RF hepatic ablation. Two geometrical configurations were investigated. The RF electrode was placed at distances of 1 and 5 mm from a large vessel (10 mm diameter. Results When the ablation procedure takes longer than 1–2 min, the attained coagulation zone obtained with both time-varying h and constant h does not differ significantly. However, for short duration ablation (5–10 s and when the electrode is 1 mm away from the vessel, the use of constant h can lead to errors as high as 20% in the estimation of the coagulation zone. Conclusion For tumor ablation procedures typically lasting at least 5 min, this study shows that modeling the heat sink effect of large vessels by applying constant h as a boundary condition will yield precise results while reducing computational complexity. However, for other thermal therapies with shorter treatment using a time-varying h may be necessary.

  12. Tritium metabolism in rat tissues

    International Nuclear Information System (INIS)

    Takeda, H.

    1982-01-01

    As part of a series of studies designed to evaluate the relative radiotoxicity of various tritiated compounds, metabolism of tritium in rat tissues was studied after administration of tritiated water, leucine, thymidine, and glucose. The distribution and retention of tritium varied widely, depending on the chemical compound administered. Tritium introduced as tritiated water behaved essentially as body water and became uniformly distributed among the tissues. However, tritium administered as organic compounds resulted in relatively high incorporation into tissue constituents other than water, and its distribution differed among the various tissues. Moreover, the excretion rate of tritium from tissues was slower for tritiated organic compounds than for tritiated water. Administrationof tritiated organic compounds results in higher radiation doses to the tissues than does administration of tritiated water. Among the tritiated compounds examined, for equal radioactivity administered, leucine gave the highest radiation dose, followed in turn by thymidine, glucose, and water. (author)

  13. Bioprinting for Neural Tissue Engineering.

    Science.gov (United States)

    Knowlton, Stephanie; Anand, Shivesh; Shah, Twisha; Tasoglu, Savas

    2018-01-01

    Bioprinting is a method by which a cell-encapsulating bioink is patterned to create complex tissue architectures. Given the potential impact of this technology on neural research, we review the current state-of-the-art approaches for bioprinting neural tissues. While 2D neural cultures are ubiquitous for studying neural cells, 3D cultures can more accurately replicate the microenvironment of neural tissues. By bioprinting neuronal constructs, one can precisely control the microenvironment by specifically formulating the bioink for neural tissues, and by spatially patterning cell types and scaffold properties in three dimensions. We review a range of bioprinted neural tissue models and discuss how they can be used to observe how neurons behave, understand disease processes, develop new therapies and, ultimately, design replacement tissues. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Computational Modeling in Tissue Engineering

    CERN Document Server

    2013-01-01

    One of the major challenges in tissue engineering is the translation of biological knowledge on complex cell and tissue behavior into a predictive and robust engineering process. Mastering this complexity is an essential step towards clinical applications of tissue engineering. This volume discusses computational modeling tools that allow studying the biological complexity in a more quantitative way. More specifically, computational tools can help in:  (i) quantifying and optimizing the tissue engineering product, e.g. by adapting scaffold design to optimize micro-environmental signals or by adapting selection criteria to improve homogeneity of the selected cell population; (ii) quantifying and optimizing the tissue engineering process, e.g. by adapting bioreactor design to improve quality and quantity of the final product; and (iii) assessing the influence of the in vivo environment on the behavior of the tissue engineering product, e.g. by investigating vascular ingrowth. The book presents examples of each...

  15. Polyploidization in liver tissue.

    Science.gov (United States)

    Gentric, Géraldine; Desdouets, Chantal

    2014-02-01

    Polyploidy (alias whole genome amplification) refers to organisms containing more than two basic sets of chromosomes. Polyploidy was first observed in plants more than a century ago, and it is known that such processes occur in many eukaryotes under a variety of circumstances. In mammals, the development of polyploid cells can contribute to tissue differentiation and, therefore, possibly a gain of function; alternately, it can be associated with development of disease, such as cancer. Polyploidy can occur because of cell fusion or abnormal cell division (endoreplication, mitotic slippage, or cytokinesis failure). Polyploidy is a common characteristic of the mammalian liver. Polyploidization occurs mainly during liver development, but also in adults with increasing age or because of cellular stress (eg, surgical resection, toxic exposure, or viral infections). This review will explore the mechanisms that lead to the development of polyploid cells, our current state of understanding of how polyploidization is regulated during liver growth, and its consequence on liver function. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  16. Soft tissue angiosarcomas

    Energy Technology Data Exchange (ETDEWEB)

    Morales, P.H.; Lindberg, R.D.; Barkley, H.T.

    1981-12-01

    From 1949 to 1979, 12 patients with soft tissue angiosarcoma received radiotherapy (alone or in combination with other modalities of treatment) with curative intent at The University of Texas M.D. Anderson Hospital and Tumor Institute. The primary site was the head and neck in six patients (scalp, four; maxillary antrum, one; and oral tongue, one), the breast in four patients, and the thigh in two patients. All four patients with angiosarcoma of the scalp had advanced multifocal tumors, and two of them had clinically positive neck nodes. None of these tumors were controlled locally, and local recurrences occurred within and/or at a distance from the generous fields of irradiation. The remaining two patients with head and neck lesions had their disease controlled by surgery and postoperative irradiation. Three of the four angiosarcomas of the breast were primary cases which were treated by a combination of surgery (excisional biopsy, simple mastectomy, radical mastectomy) and postoperative irradiation. One patient also received adjuvant chemotherapy. The fourth patient was treated for scar recurrence after radical mastectomy. All four patients had their disease locally controlled, and two of them have survived over 5 years. The two patients with angiosarcoma of the thigh were treated by conservative surgical excision and postoperative irradiation. One patient had her disease controlled; the other had a local recurrence requiring hip disarticulation and subsequent hemipelvectomy for salvage.

  17. Monitoring soft tissue coagulation by optical spectroscopy

    Science.gov (United States)

    Lihachev, A.; Lihacova, I.; Heinrichs, H.; Spigulis, J.; Trebst, T.; Wehner, M.

    2017-12-01

    Laser tissue welding (LTW) or laser tissue soldering (LTS) is investigated since many years for treatment of incisions, wound closure and anastomosis of vessels [1, 2]. Depending on the process, a certain temperature in the range between 65 °C to 85 °C must be reached and held for a few seconds. Care has to be taken not to overheat the tissue, otherwise necrosis or tissue carbonization may occur and will impair wound healing. Usually the temperature is monitored during the process to control the laser power [3]. This requires either bulky equipment or expensive and fragile infrared fibers to feed the temperature signal to an infrared detector. Alternatively, changes in tissue morphology can be directly observed by analysis of spectral reflectance. We investigate spectral changes in the range between 400 nm to 900 nm wavelength. Characteristic spectral changes occur when the temperature of tissue samples increase above 70 °C which is a typical setpoint value for temperature control of coagulation. We conclude that simple spectroscopy in the visible range can provide valuable information during LTS and LTW and probably replace the delicate measurement of temperature. A major advantage is that optical measurements can be performed using standard optical fibers and can be easily integrated into a surgical tool.

  18. Synthetic Phage for Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    So Young Yoo

    2014-01-01

    Full Text Available Controlling structural organization and signaling motif display is of great importance to design the functional tissue regenerating materials. Synthetic phage, genetically engineered M13 bacteriophage has been recently introduced as novel tissue regeneration materials to display a high density of cell-signaling peptides on their major coat proteins for tissue regeneration purposes. Structural advantages of their long-rod shape and monodispersity can be taken together to construct nanofibrous scaffolds which support cell proliferation and differentiation as well as direct orientation of their growth in two or three dimensions. This review demonstrated how functional synthetic phage is designed and subsequently utilized for tissue regeneration that offers potential cell therapy.

  19. Tissue Harmonic Synthetic Aperture Imaging

    DEFF Research Database (Denmark)

    Rasmussen, Joachim

    The main purpose of this PhD project is to develop an ultrasonic method for tissue harmonic synthetic aperture imaging. The motivation is to advance the field of synthetic aperture imaging in ultrasound, which has shown great potentials in the clinic. Suggestions for synthetic aperture tissue...... system complexity compared to conventional synthetic aperture techniques. In this project, SASB is sought combined with a pulse inversion technique for 2nd harmonic tissue harmonic imaging. The advantages in tissue harmonic imaging (THI) are expected to further improve the image quality of SASB...

  20. Modeling collagen remodeling in tissue engineered cardiovascular tissues

    NARCIS (Netherlands)

    Soares, A.L.F.

    2012-01-01

    Commonly, heart valve replacements consist of non-living materials lacking the ability to grow, repair and remodel. Tissue engineering (TE) offers a promising alternative to these replacement strategies since it can overcome its disadvantages. The technique aims to create an autologous living tissue

  1. Clinical management of soft tissue sarcomas

    International Nuclear Information System (INIS)

    Pinedo, H.M.; Verweij, J.

    1986-01-01

    This book is concerned with the clinical management of soft tissue sarcomas. Topics covered include: Radiotherapy; Pathology of soft tissue sarcomas; Surgical treatment of soft tissue sarcomas; and Chemotherapy in advanced soft tissue sarcomas

  2. Aging changes in organs - tissue - cells

    Science.gov (United States)

    ... and structure to the skin and internal organs. Epithelial tissue provides a covering for deeper body layers. The ... such as the gastrointestinal system, are made of epithelial tissue. Muscle tissue includes three types of tissue: Striated ...

  3. Evaluation of shrinkage temperature of bovine pericardium tissue for bioprosthetic heart valve application by differential scanning calorimetry and freeze-drying microscopy

    Directory of Open Access Journals (Sweden)

    Virgilio Tattini Jr

    2007-03-01

    Full Text Available Bovine pericardium bioprosthesis has become a commonly accepted device for heart valve replacement. Present practice relies on the measurement of shrinkage temperature, observed as a dramatic shortening of tissue length. Several reports in the last decade have utilized differential scanning calorimetry (DSC as an alternative method to determine the shrinkage temperature, which is accompanied by the absorption of heat, giving rise to an endothermic peak over the shrinkage temperature range of biological tissues. Usually, freeze-drying microscope is used to determine collapse temperature during the lyophilization of solutions. On this experiment we used this technique to study the shrinkage event. The aim of this work was to compare the results of shrinkage temperature obtained by DSC with the results obtained by freeze-drying microscopy. The results showed that both techniques provided excellent sensitivity and reproducibility, and gave information on the thermal shrinkage transition via the thermodynamical parameters inherent of each method.

  4. Chitin Scaffolds in Tissue Engineering

    Science.gov (United States)

    Jayakumar, Rangasamy; Chennazhi, Krishna Prasad; Srinivasan, Sowmya; Nair, Shantikumar V.; Furuike, Tetsuya; Tamura, Hiroshi

    2011-01-01

    Tissue engineering/regeneration is based on the hypothesis that healthy stem/progenitor cells either recruited or delivered to an injured site, can eventually regenerate lost or damaged tissue. Most of the researchers working in tissue engineering and regenerative technology attempt to create tissue replacements by culturing cells onto synthetic porous three-dimensional polymeric scaffolds, which is currently regarded as an ideal approach to enhance functional tissue regeneration by creating and maintaining channels that facilitate progenitor cell migration, proliferation and differentiation. The requirements that must be satisfied by such scaffolds include providing a space with the proper size, shape and porosity for tissue development and permitting cells from the surrounding tissue to migrate into the matrix. Recently, chitin scaffolds have been widely used in tissue engineering due to their non-toxic, biodegradable and biocompatible nature. The advantage of chitin as a tissue engineering biomaterial lies in that it can be easily processed into gel and scaffold forms for a variety of biomedical applications. Moreover, chitin has been shown to enhance some biological activities such as immunological, antibacterial, drug delivery and have been shown to promote better healing at a faster rate and exhibit greater compatibility with humans. This review provides an overview of the current status of tissue engineering/regenerative medicine research using chitin scaffolds for bone, cartilage and wound healing applications. We also outline the key challenges in this field and the most likely directions for future development and we hope that this review will be helpful to the researchers working in the field of tissue engineering and regenerative medicine. PMID:21673928

  5. [Cellular subcutaneous tissue. Anatomic observations].

    Science.gov (United States)

    Marquart-Elbaz, C; Varnaison, E; Sick, H; Grosshans, E; Cribier, B

    2001-11-01

    We showed in a companion paper that the definition of the French "subcutaneous cellular tissue" considerably varied from the 18th to the end of the 20th centuries and has not yet reached a consensus. To address the anatomic reality of this "subcutaneous cellular tissue", we investigated the anatomic structures underlying the fat tissue in normal human skin. Sixty specimens were excised from the surface to the deep structures (bone, muscle, cartilage) on different body sites of 3 cadavers from the Institut d'Anatomie Normale de Strasbourg. Samples were paraffin-embedded, stained and analysed with a binocular microscope taking x 1 photographs. Specimens were also excised and fixed after subcutaneous injection of Indian ink, after mechanic tissue splitting and after performing artificial skin folds. The aspects of the deep parts of the skin greatly varied according to their anatomic localisation. Below the adipose tissue, we often found a lamellar fibrous layer which extended from the interlobular septa and contained horizontally distributed fat cells. No specific tissue below the hypodermis was observed. Artificial skin folds concerned either exclusively the dermis, when they were superficial or included the hypodermis, but no specific structure was apparent in the center of the fold. India ink diffused to the adipose tissue, mainly along the septa, but did not localise in a specific subcutaneous compartment. This study shows that the histologic aspects of the deep part of the skin depend mainly on the anatomic localisation. Skin is composed of epidermis, dermis and hypodermis and thus the hypodermis can not be considered as being "subcutaneous". A difficult to individualise, fibrous lamellar structure in continuity with the interlobular septa is often found under the fat lobules. This structure is a cleavage line, as is always the case with loose connective tissues, but belongs to the hypodermis (i.e. fat tissue). No specific tissue nor any virtual space was

  6. Ex vivo evaluation of super pulse diode laser system with smart temperature feedback for contact soft-tissue surgery

    Science.gov (United States)

    Yaroslavsky, Ilya; Boutoussov, Dmitri; Vybornov, Alexander; Perchuk, Igor; Meleshkevich, Val; Altshuler, Gregory

    2018-02-01

    Until recently, Laser Diodes (LD) have been limited in their ability to deliver high peak power levels, which, in turn, limited their clinical capabilities. New technological developments made possible advent of "super pulse" LD (SPLD). Moreover, advanced means of smart thermal feedback enable precise control of laser power, thus ensuring safe and optimally efficacious application. In this work, we have evaluated a prototype SPLD system ex vivo. The device provided up to 25 W average and up to 150 W pulse power at 940 nm wavelength. The laser was operated in the thermal feedback-controlled mode, where power of the laser was varied automatically as a function of real-time thermal feedback to maintain constant tip temperature. The system was also equipped with a fiber tip initiated with advanced TiO2 /tungsten technique. Evaluation methods were designed to assess: 1) Speed and depth of cutting; 2) Dimensions of coagulative margin. The SPLD system was compared with industry-leading conventional diode and CO2 devices. The results indicate that the SPLD system provides increase in speed of controlled cutting by a factor of >2 in comparison with the conventional diode laser and approaching that of CO2 device. The produced ratio of the depth of cut to the thermal damage margin was significantly higher than conventional diodes and close to that of the CO2 system, suggesting optimal hemostasis conditions. SPLD technology with real-time temperature control has a potential for creating a new standard of care in the field of precision soft tissue surgery.

  7. Biomaterials for tissue engineering: summary

    Science.gov (United States)

    Christenson, L.; Mikos, A. G.; Gibbons, D. F.; Picciolo, G. L.; McIntire, L. V. (Principal Investigator)

    1997-01-01

    This article summarizes presentations and discussion at the workshop "Enabling Biomaterial Technology for Tissue Engineering," which was held during the Fifth World Biomaterials Congress in May 1996. Presentations covered the areas of material substrate architecture, barrier effects, and cellular response, including analysis of biomaterials challenges involved in producing specific tissue-engineered products.

  8. Biomimetic heterogenous elastic tissue development.

    Science.gov (United States)

    Tsai, Kai Jen; Dixon, Simon; Hale, Luke Richard; Darbyshire, Arnold; Martin, Daniel; de Mel, Achala

    2017-01-01

    There is an unmet need for artificial tissue to address current limitations with donor organs and problems with donor site morbidity. Despite the success with sophisticated tissue engineering endeavours, which employ cells as building blocks, they are limited to dedicated labs suitable for cell culture, with associated high costs and long tissue maturation times before available for clinical use. Direct 3D printing presents rapid, bespoke, acellular solutions for skull and bone repair or replacement, and can potentially address the need for elastic tissue, which is a major constituent of smooth muscle, cartilage, ligaments and connective tissue that support organs. Thermoplastic polyurethanes are one of the most versatile elastomeric polymers. Their segmented block copolymeric nature, comprising of hard and soft segments allows for an almost limitless potential to control physical properties and mechanical behaviour. Here we show direct 3D printing of biocompatible thermoplastic polyurethanes with Fused Deposition Modelling, with a view to presenting cell independent in-situ tissue substitutes. This method can expeditiously and economically produce heterogenous, biomimetic elastic tissue substitutes with controlled porosity to potentially facilitate vascularisation. The flexibility of this application is shown here with tubular constructs as exemplars. We demonstrate how these 3D printed constructs can be post-processed to incorporate bioactive molecules. This efficacious strategy, when combined with the privileges of digital healthcare, can be used to produce bespoke elastic tissue substitutes in-situ, independent of extensive cell culture and may be developed as a point-of-care therapy approach.

  9. In vitro study of the biological activity of RNAs after incubation of hog liver, heart and brain tissue at room temperature

    DEFF Research Database (Denmark)

    Reichert, G H; Issinger, O G

    1985-01-01

    The biological activity of RNA, isolated from tissue which was incubated for 1, 3, or 6 hours at room temperature (simulation of post-mortem conditions), was preserved. However, the different organs used differ from each other. When liver is used, qualitative differences in the in vitro translati...... RNase inhibitors during thawing to reduce the loss of biological activity....

  10. Tissue Engineering of the Penis

    Directory of Open Access Journals (Sweden)

    Manish N. Patel

    2011-01-01

    Full Text Available Congenital disorders, cancer, trauma, or other conditions of the genitourinary tract can lead to significant organ damage or loss of function, necessitating eventual reconstruction or replacement of the damaged structures. However, current reconstructive techniques are limited by issues of tissue availability and compatibility. Physicians and scientists have begun to explore tissue engineering and regenerative medicine strategies for repair and reconstruction of the genitourinary tract. Tissue engineering allows the development of biological substitutes which could potentially restore normal function. Tissue engineering efforts designed to treat or replace most organs are currently being undertaken. Most of these efforts have occurred within the past decade. However, before these engineering techniques can be applied to humans, further studies are needed to ensure the safety and efficacy of these new materials. Recent progress suggests that engineered urologic tissues and cell therapy may soon have clinical applicability.

  11. Commercial considerations in tissue engineering.

    Science.gov (United States)

    Mansbridge, Jonathan

    2006-10-01

    Tissue engineering is a field with immense promise. Using the example of an early tissue-engineered skin implant, Dermagraft, factors involved in the successful commercial development of devices of this type are explored. Tissue engineering has to strike a balance between tissue culture, which is a resource-intensive activity, and business considerations that are concerned with minimizing cost and maximizing customer convenience. Bioreactor design takes place in a highly regulated environment, so factors to be incorporated into the concept include not only tissue culture considerations but also matters related to asepsis, scaleup, automation and ease of use by the final customer. Dermagraft is an allogeneic tissue. Stasis preservation, in this case cryopreservation, is essential in allogeneic tissue engineering, allowing sterility testing, inventory control and, in the case of Dermagraft, a cellular stress that may be important for hormesis following implantation. Although the use of allogeneic cells provides advantages in manufacturing under suitable conditions, it raises the spectre of immunological rejection. Such rejection has not been experienced with Dermagraft. Possible reasons for this and the vision of further application of allogeneic tissues are important considerations in future tissue-engineered cellular devices. This review illustrates approaches that indicate some of the criteria that may provide a basis for further developments. Marketing is a further requirement for success, which entails understanding of the mechanism of action of the procedure, and is illustrated for Dermagraft. The success of a tissue-engineered product is dependent on many interacting operations, some discussed here, each of which must be performed simultaneously and well.

  12. Tissue bioengineering and artificial organs.

    Science.gov (United States)

    Llames, Sara; García, Eva; Otero Hernández, Jesús; Meana, Alvaro

    2012-01-01

    The scarcity of organs and tissues for transplant and the need of immunosuppressive drugs to avoid rejection constitute two reasons that justify organ and tissue production in the laboratory. Tissue engineering based tissues (TE) could allow to regenerate the whole organ from a fragment or even to produce several organs from an organ donor for grafting purposes. TE is based in: (1) the ex vivo expansion of cells, (2) the seeding of these expanded cells in tridimensional structures that mimic physiological conditions and, (3) grafting the prototype. In order to graft big structures it is necessary that the organ or tissue produced "ex vivo" bears a vascular tree to ensure the nutrition of its deep layers. At present, no technology has been developed to provide this vascular tree to TE derived products. Thus, these tissues must be thin enough to acquire nutrients during the first days by diffusion from surrounding tissues. This fact constitutes nowadays the greatest limitation of technologies for organ development in the laboratory.In this chapter, all these problems and their possible solutions are commented. Also, the present status of TE techniques in the regeneration of different organ systems is reviewed.

  13. Physicochemical processes in embryonic plant tissue during the transition to the state of cold anabiosis and storage at liquid nitrogen temperature

    Science.gov (United States)

    Khodko, A. T.; Lysak, Yu. S.

    2017-10-01

    Critical opalescence phenomenon was observed in the cytoplasm of garlic embryonic tissue—meristem—upon cooling in liquid nitrogen vapor, indicating liquid-liquid phase transition in the system. It was established that cells of the meristem tissue survive the cooling-thawing cycle. We suggest that the transition of meristem tissue to the state of anabiosis is mainly due to a drastic slowing of the diffusion in the cytoplasm caused by the passage of the solution through the critical point, followed by the formation of a dispersed system—a highly concentrated emulsion—as a result of a liquid-liquid phase transition. This macrophase separation is characteristic of polymer-solvent systems. We established the regime of cooling down to liquid nitrogen temperature and subsequent thawing in the cryopreservation cycle for the biological object under study, which ensures the preservation of tissue viability.

  14. Multimodality instrument for tissue characterization

    Science.gov (United States)

    Mah, Robert W. (Inventor); Andrews, Russell J. (Inventor)

    2004-01-01

    A system with multimodality instrument for tissue identification includes a computer-controlled motor driven heuristic probe with a multisensory tip. For neurosurgical applications, the instrument is mounted on a stereotactic frame for the probe to penetrate the brain in a precisely controlled fashion. The resistance of the brain tissue being penetrated is continually monitored by a miniaturized strain gauge attached to the probe tip. Other modality sensors may be mounted near the probe tip to provide real-time tissue characterizations and the ability to detect the proximity of blood vessels, thus eliminating errors normally associated with registration of pre-operative scans, tissue swelling, elastic tissue deformation, human judgement, etc., and rendering surgical procedures safer, more accurate, and efficient. A neural network program adaptively learns the information on resistance and other characteristic features of normal brain tissue during the surgery and provides near real-time modeling. A fuzzy logic interface to the neural network program incorporates expert medical knowledge in the learning process. Identification of abnormal brain tissue is determined by the detection of change and comparison with previously learned models of abnormal brain tissues. The operation of the instrument is controlled through a user friendly graphical interface. Patient data is presented in a 3D stereographics display. Acoustic feedback of selected information may optionally be provided. Upon detection of the close proximity to blood vessels or abnormal brain tissue, the computer-controlled motor immediately stops probe penetration. The use of this system will make surgical procedures safer, more accurate, and more efficient. Other applications of this system include the detection, prognosis and treatment of breast cancer, prostate cancer, spinal diseases, and use in general exploratory surgery.

  15. Chitosan adhesive for laser tissue repair

    Science.gov (United States)

    Lauto, A.; Stoodley, M.; Avolio, A.; Foster, L. J. R.

    2006-02-01

    Background. Laser tissue repair usually relies on haemoderivate solders, based on serum albumin. These solders have intrinsic limitations that impair their widespread use, such as limited repair strength, high solubility, brittleness and viral transmission. Furthermore, the solder activation temperature (65-70 °C) can induce significant damage to tissue. In this study, a new laser-activated biomaterial for tissue repair was developed and tested in vitro and in vivo to overcome some of the shortcomings of traditional solders. Materials and Methods. Flexible and insoluble strips of chitosan adhesive (surface area ~34 mm2, thickness ~20 μm) were developed and bonded on sheep intestine with a laser fluence and irradiance of 52 +/- 2 J/cm2 and ~15 W/cm2 respectively. The temperature between tissue and adhesive was measured using small thermocouples. The strength of repaired tissue was tested by a calibrated tensiometer. The adhesive was also bonded in vivo to the sciatic nerve of rats to assess the thermal damage induced by the laser (fluence = 65 +/- 11 J/cm2, irradiance = 15 W/cm2) four days post-operatively. Results. Chitosan adhesives successfully repaired intestine tissue, achieving a repair strength of 0.50 +/- 0.15 N (shear stress = 14.7 +/- 4.7 KPa, n=30) at a temperature of 60-65 °C. The laser caused demyelination of axons at the operated site; nevertheless, the myelinated axons retained their normal morphology proximally and distally.

  16. Lymphoid Tissue Grafts in Man

    Energy Technology Data Exchange (ETDEWEB)

    Kay, H. E.M. [Royal Marsden Hospital, Institute of Cancer Research, London (United Kingdom)

    1969-07-15

    Grafts of lymphoid tissue or of lymphoid stem cells may be appropriate in the treatment of some congenital immune deficiency disorders. The reasons for preferring tissues of foetal origin are discussed and the evidence for foetal immunocompetence is briefly summarized. Methods of storing foetal liver cells and cells or fragments of thymus are mentioned, and the organization of the Foetal Tissue Bank of the Royal Marsden Hospital is described. Clinical data from transplantation of lymphoid cells in various immune deficiency disorders are briefly presented. (author)

  17. Soft tissue tumors - imaging methods

    International Nuclear Information System (INIS)

    Arlart, I.P.

    1985-01-01

    Soft Tissue Tumors - Imaging Methods: Imaging methods play an important diagnostic role in soft tissue tumors concerning a preoperative evaluation of localization, size, topographic relationship, dignity, and metastatic disease. The present paper gives an overview about diagnostic methods available today such as ultrasound, thermography, roentgenographic plain films and xeroradiography, radionuclide methods, computed tomography, lymphography, angiography, and magnetic resonance imaging. Besides sonography particularly computed tomography has the most important diagnostic value in soft tissue tumors. The application of a recently developed method, the magnetic resonance imaging, cannot yet be assessed in its significance. (orig.) [de

  18. Force transmission in epithelial tissues.

    Science.gov (United States)

    Vasquez, Claudia G; Martin, Adam C

    2016-03-01

    In epithelial tissues, cells constantly generate and transmit forces between each other. Forces generated by the actomyosin cytoskeleton regulate tissue shape and structure and also provide signals that influence cells' decisions to divide, die, or differentiate. Forces are transmitted across epithelia because cells are mechanically linked through junctional complexes, and forces can propagate through the cell cytoplasm. Here, we review some of the molecular mechanisms responsible for force generation, with a specific focus on the actomyosin cortex and adherens junctions. We then discuss evidence for how these mechanisms promote cell shape changes and force transmission in tissues. © 2016 Wiley Periodicals, Inc.

  19. Low-temperature X-ray microanalysis of the differentiating vascular tissue in root tips of Lemna minor L

    Energy Technology Data Exchange (ETDEWEB)

    Echlin, P [Univ. of Cambridge, England; Lai, C E; Hayes, T L

    1982-06-01

    The fracture faces of bulk-frozen tissue offer a number of advantages for the analysis of diffusible elements. They are easy to prepare, remain uncontaminated, and, unlike most frozen-hydrated sections, can be shown to exist in a fully hydrated state throughout examination and analysis. Root tips of Lemna minor briefly treated with a polymeric cryoprotectant are quench frozen in melting nitrogen. Fractures are prepared using the AMRAY Biochamber, lightly etched if necessary to reveal surface detail and carbon coated while maintaining the specimen at 110 K. The frozen-hydrated fracture faces are analyzed at 110 K using the P/B ratio method which is less sensitive to changes in surface geometry and variations in beam current. The method has been used to investigate the distribution of seven elements (Na/sup +/, Mg/sup + +/, P, S, Cl/sup -/, K/sup +/ and Ca/sup + +/) in the developing vascular tissue of the root tip. The microprobe can measure relative elemental ratios at the cellular level and the results from this present study reveal important variations in different parts of the root. The younger, more actively dividing cells, appear to have a slightly higher concentration of diffusible ions in comparison to the somewhat older tissues which have begun to differentiate into what are presumed to be functional vascular elements.

  20. The relevance of MRI for patient modeling in head and neck hyperthermia treatment planning: A comparison of CT and CT-MRI based tissue segmentation on simulated temperature

    International Nuclear Information System (INIS)

    Verhaart, René F.; Paulides, Margarethus M.; Fortunati, Valerio; Walsum, Theo van; Veenland, Jifke F.; Verduijn, Gerda M.; Lugt, Aad van der

    2014-01-01

    Purpose: In current clinical practice, head and neck (H and N) hyperthermia treatment planning (HTP) is solely based on computed tomography (CT) images. Magnetic resonance imaging (MRI) provides superior soft-tissue contrast over CT. The purpose of the authors’ study is to investigate the relevance of using MRI in addition to CT for patient modeling in H and N HTP. Methods: CT and MRI scans were acquired for 11 patients in an immobilization mask. Three observers manually segmented on CT, MRI T1 weighted (MRI-T1w), and MRI T2 weighted (MRI-T2w) images the following thermo-sensitive tissues: cerebrum, cerebellum, brainstem, myelum, sclera, lens, vitreous humor, and the optical nerve. For these tissues that are used for patient modeling in H and N HTP, the interobserver variation of manual tissue segmentation in CT and MRI was quantified with the mean surface distance (MSD). Next, the authors compared the impact of CT and CT and MRI based patient models on the predicted temperatures. For each tissue, the modality was selected that led to the lowest observer variation and inserted this in the combined CT and MRI based patient model (CT and MRI), after a deformable image registration. In addition, a patient model with a detailed segmentation of brain tissues (including white matter, gray matter, and cerebrospinal fluid) was created (CT and MRI db ). To quantify the relevance of MRI based segmentation for H and N HTP, the authors compared the predicted maximum temperatures in the segmented tissues (T max ) and the corresponding specific absorption rate (SAR) of the patient models based on (1) CT, (2) CT and MRI, and (3) CT and MRI db . Results: In MRI, a similar or reduced interobserver variation was found compared to CT (maximum of median MSD in CT: 0.93 mm, MRI-T1w: 0.72 mm, MRI-T2w: 0.66 mm). Only for the optical nerve the interobserver variation is significantly lower in CT compared to MRI (median MSD in CT: 0.58 mm, MRI-T1w: 1.27 mm, MRI-T2w: 1.40 mm). Patient

  1. The relevance of MRI for patient modeling in head and neck hyperthermia treatment planning: A comparison of CT and CT-MRI based tissue segmentation on simulated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Verhaart, René F., E-mail: r.f.verhaart@erasmusmc.nl; Paulides, Margarethus M. [Hyperthermia Unit, Department of Radiation Oncology, Erasmus MC - Cancer Institute, Groene Hilledijk 301, Rotterdam 3008 AE (Netherlands); Fortunati, Valerio; Walsum, Theo van; Veenland, Jifke F. [Biomedical Imaging Group of Rotterdam, Department of Medical Informatics and Radiology, Erasmus MC, Dr. Molewaterplein 50/60, Rotterdam 3015 GE (Netherlands); Verduijn, Gerda M. [Department of Radiation Oncology, Erasmus MC - Cancer Institute, Groene Hilledijk 301, Rotterdam 3008 AE (Netherlands); Lugt, Aad van der [Department of Radiology, Erasmus MC, Dr. Molewaterplein 50/60, Rotterdam 3015 GE (Netherlands)

    2014-12-15

    Purpose: In current clinical practice, head and neck (H and N) hyperthermia treatment planning (HTP) is solely based on computed tomography (CT) images. Magnetic resonance imaging (MRI) provides superior soft-tissue contrast over CT. The purpose of the authors’ study is to investigate the relevance of using MRI in addition to CT for patient modeling in H and N HTP. Methods: CT and MRI scans were acquired for 11 patients in an immobilization mask. Three observers manually segmented on CT, MRI T1 weighted (MRI-T1w), and MRI T2 weighted (MRI-T2w) images the following thermo-sensitive tissues: cerebrum, cerebellum, brainstem, myelum, sclera, lens, vitreous humor, and the optical nerve. For these tissues that are used for patient modeling in H and N HTP, the interobserver variation of manual tissue segmentation in CT and MRI was quantified with the mean surface distance (MSD). Next, the authors compared the impact of CT and CT and MRI based patient models on the predicted temperatures. For each tissue, the modality was selected that led to the lowest observer variation and inserted this in the combined CT and MRI based patient model (CT and MRI), after a deformable image registration. In addition, a patient model with a detailed segmentation of brain tissues (including white matter, gray matter, and cerebrospinal fluid) was created (CT and MRI{sub db}). To quantify the relevance of MRI based segmentation for H and N HTP, the authors compared the predicted maximum temperatures in the segmented tissues (T{sub max}) and the corresponding specific absorption rate (SAR) of the patient models based on (1) CT, (2) CT and MRI, and (3) CT and MRI{sub db}. Results: In MRI, a similar or reduced interobserver variation was found compared to CT (maximum of median MSD in CT: 0.93 mm, MRI-T1w: 0.72 mm, MRI-T2w: 0.66 mm). Only for the optical nerve the interobserver variation is significantly lower in CT compared to MRI (median MSD in CT: 0.58 mm, MRI-T1w: 1.27 mm, MRI-T2w: 1.40 mm

  2. The relevance of MRI for patient modeling in head and neck hyperthermia treatment planning: a comparison of CT and CT-MRI based tissue segmentation on simulated temperature.

    Science.gov (United States)

    Verhaart, René F; Fortunati, Valerio; Verduijn, Gerda M; van der Lugt, Aad; van Walsum, Theo; Veenland, Jifke F; Paulides, Margarethus M

    2014-12-01

    In current clinical practice, head and neck (H&N) hyperthermia treatment planning (HTP) is solely based on computed tomography (CT) images. Magnetic resonance imaging (MRI) provides superior soft-tissue contrast over CT. The purpose of the authors' study is to investigate the relevance of using MRI in addition to CT for patient modeling in H&N HTP. CT and MRI scans were acquired for 11 patients in an immobilization mask. Three observers manually segmented on CT, MRI T1 weighted (MRI-T1w), and MRI T2 weighted (MRI-T2w) images the following thermo-sensitive tissues: cerebrum, cerebellum, brainstem, myelum, sclera, lens, vitreous humor, and the optical nerve. For these tissues that are used for patient modeling in H&N HTP, the interobserver variation of manual tissue segmentation in CT and MRI was quantified with the mean surface distance (MSD). Next, the authors compared the impact of CT and CT and MRI based patient models on the predicted temperatures. For each tissue, the modality was selected that led to the lowest observer variation and inserted this in the combined CT and MRI based patient model (CT and MRI), after a deformable image registration. In addition, a patient model with a detailed segmentation of brain tissues (including white matter, gray matter, and cerebrospinal fluid) was created (CT and MRIdb). To quantify the relevance of MRI based segmentation for H&N HTP, the authors compared the predicted maximum temperatures in the segmented tissues (Tmax) and the corresponding specific absorption rate (SAR) of the patient models based on (1) CT, (2) CT and MRI, and (3) CT and MRIdb. In MRI, a similar or reduced interobserver variation was found compared to CT (maximum of median MSD in CT: 0.93 mm, MRI-T1w: 0.72 mm, MRI-T2w: 0.66 mm). Only for the optical nerve the interobserver variation is significantly lower in CT compared to MRI (median MSD in CT: 0.58 mm, MRI-T1w: 1.27 mm, MRI-T2w: 1.40 mm). Patient models based on CT (Tmax: 38.0 °C) and CT and MRI

  3. Dynamics of anisotropic tissue growth

    Energy Technology Data Exchange (ETDEWEB)

    Bittig, Thomas; Juelicher, Frank [Max Planck Institute for the Physics of Complex Systems, Noethnitzer Strasse 38, 01187 Dresden (Germany); Wartlick, Ortrud; Kicheva, Anna; Gonzalez-Gaitan, Marcos [Department of Biochemistry and Department of Molecular Biology, Geneva University, Sciences II, Quai Ernest-Ansermet 30, 1211 Geneva 4 (Switzerland)], E-mail: Marcos.Gonzalez@biochem.unige.ch, E-mail: julicher@pks.mpg.de

    2008-06-15

    We study the mechanics of tissue growth via cell division and cell death (apoptosis). The rearrangements of cells can on large scales and times be captured by a continuum theory which describes the tissue as an effective viscous material with active stresses generated by cell division. We study the effects of anisotropies of cell division on cell rearrangements and show that average cellular trajectories exhibit anisotropic scaling behaviors. If cell division and apoptosis balance, there is no net growth, but for anisotropic cell division the tissue undergoes spontaneous shear deformations. Our description is relevant for the study of developing tissues such as the imaginal disks of the fruit fly Drosophila melanogaster, which grow anisotropically.

  4. Molecular, cellular, and tissue engineering

    CERN Document Server

    Bronzino, Joseph D

    2015-01-01

    Known as the bible of biomedical engineering, The Biomedical Engineering Handbook, Fourth Edition, sets the standard against which all other references of this nature are measured. As such, it has served as a major resource for both skilled professionals and novices to biomedical engineering. Molecular, Cellular, and Tissue Engineering, the fourth volume of the handbook, presents material from respected scientists with diverse backgrounds in molecular biology, transport phenomena, physiological modeling, tissue engineering, stem cells, drug delivery systems, artificial organs, and personalized medicine. More than three dozen specific topics are examined, including DNA vaccines, biomimetic systems, cardiovascular dynamics, biomaterial scaffolds, cell mechanobiology, synthetic biomaterials, pluripotent stem cells, hematopoietic stem cells, mesenchymal stem cells, nanobiomaterials for tissue engineering, biomedical imaging of engineered tissues, gene therapy, noninvasive targeted protein and peptide drug deliver...

  5. American Association of Tissue Banks

    Science.gov (United States)

    ... Committees Accreditation American Board of Tissue Banking Bylaws / Ethics Communications Donor Family Services Ad Hoc Committee Education Finance ... Bureau Accredited Bank Search Bookstore Bulletins Global Topics Communications & Media Job Center News Releases Patients and Community Useful ...

  6. Tissue equivalence in neutron dosimetry

    International Nuclear Information System (INIS)

    Nutton, D.H.; Harris, S.J.

    1980-01-01

    A brief review is presented of the essential features of neutron tissue equivalence for radiotherapy and gives the results of a computation of relative absorbed dose for 14 MeV neutrons, using various tissue models. It is concluded that for the Bragg-Gray equation for ionometric dosimetry it is not sufficient to define the value of W to high accuracy and that it is essential that, for dosimetric measurements to be applicable to real body tissue to an accuracy of better than several per cent, a correction to the total absorbed dose must be made according to the test and tissue atomic composition, although variations in patient anatomy and other radiotherapy parameters will often limit the benefits of such detailed dosimetry. (U.K.)

  7. Imaging of soft tissue sarcomas

    International Nuclear Information System (INIS)

    Vanel, D.; Le Treut, A.

    1988-01-01

    Modern imaging of soft tissue sarcomas now includes ultrasounds, CT and MRI. These new techniques allow a better evaluation of initial local extension, of the response to treatment and are able to detect local recurrences early [fr

  8. Development of stereotactically guided laser interstitial thermotherapy of breast cancer: in situ measurement and analysis of the temperature field in ex vivo and in vivo adipose tissue.

    Science.gov (United States)

    Milne, P J; Parel, J M; Manns, F; Denham, D B; Gonzalez-Cirre, X; Robinson, D S

    2000-01-01

    The size (0.5-1.0 cm) of early nonpalpable breast tumors currently detected by mammography and confirmed by stereotactic core biopsy is of the order of the penetration depth of near infrared photons in breast tissue. In principle, stereotactically biopsied tumors, therefore, could be safely and efficiently treated with laser thermotherapy. The aim of the current study is to confirm the controlled heating produced by clinically relevant power levels delivered with an interstitial laser fiber optic probe adapted for use with stereotactic mammography and biopsy procedures. Temperature increases and the resultant thermal field produced by the irradiation of ex vivo (porcine and human) and in vivo (porcine) tissue models appropriate to the treatment of human breast tissue by using cw Nd:YAG laser radiation delivered with a interstitial fiber optic probe with a quartz diffusing tip, were recorded with an array of fifteen 23-gauge needle thermocouple probes connected to a laboratory computer-based data acquisition system. By using a stepwise decreasing power cycle to avoid tissue charring, acceptably symmetric thermal fields of repeatable volumetric dimensions were obtained. Reproducible thermal gradients and predictable tissue necrosis without carbonization could be induced in a 3-cm-diameter region around the fiber probe during a single treatment lasting only 3 minutes. The time-dependences of the temperature rise of the thermocouples surrounding the LITT probe were quantitatively modeled with simple linear functions during the applied laser heating cycles. Analysis of our experimental results show that reproducible, symmetric and predictable volumetric temperature increases in time can be reliably produced by interstitial laser thermotherapy. Copyright 2000 Wiley-Liss, Inc.

  9. Symptomatic heterotopic suprarenal splenic tissue

    International Nuclear Information System (INIS)

    Heider, J.; Kreft, B.; Winter, P.

    1998-01-01

    We report on a 33-year-old man with symptomatic heterotopic suprarenal splenic tissue. Heterotopic splenic tissue can often be found after posttraumatic splenectomy. It is a result of autotransplantation induced by trauma (splenosis). Additionally it can grow during embryogenic development. Such an accessory spleen is found in 10-44% of all autopsies. In this case report the patient was treated by resection due to increasing flank pain and suspected neoplasm. (orig.) [de

  10. The growth of tissue engineering.

    Science.gov (United States)

    Lysaght, M J; Reyes, J

    2001-10-01

    This report draws upon data from a variety of sources to estimate the size, scope, and growth rate of the contemporary tissue engineering enterprise. At the beginning of 2001, tissue engineering research and development was being pursued by 3,300 scientists and support staff in more than 70 startup companies or business units with a combined annual expenditure of over $600 million. Spending by tissue engineering firms has been growing at a compound annual rate of 16%, and the aggregate investment since 1990 now exceeds $3.5 billion. At the beginning of 2001, the net capital value of the 16 publicly traded tissue engineering startups had reached $2.6 billion. Firms focusing on structural applications (skin, cartilage, bone, cardiac prosthesis, and the like) comprise the fastest growing segment. In contrast, efforts in biohybrid organs and other metabolic applications have contracted over the past few years. The number of companies involved in stem cells and regenerative medicine is rapidly increasing, and this area represents the most likely nidus of future growth for tissue engineering. A notable recent trend has been the emergence of a strong commercial activity in tissue engineering outside the United States, with at least 16 European or Australian companies (22% of total) now active.

  11. Microgel Technology to Advance Modular Tissue Engineering

    NARCIS (Netherlands)

    Kamperman, Tom

    2018-01-01

    The field of tissue engineering aims to restore the function of damaged or missing tissues by combining cells and/or a supportive biomaterial scaffold into an engineered tissue construct. The construct’s design requirements are typically set by native tissues – the gold standard for tissue

  12. Tissue Banking: Current procedures, ethical consideration and ...

    African Journals Online (AJOL)

    Tissue banking provides safe and effective cells and tissues for transplantation in reconstruction surgery. Bone, amnion, skin, cartilage, heart valves and xenograft tissues are the most commonly used biological tissues. Acquisition of tissue is dependent on elaborate donor screening criteria based on medical and social ...

  13. Soft tissue engineering with micronized-gingival connective tissues.

    Science.gov (United States)

    Noda, Sawako; Sumita, Yoshinori; Ohba, Seigo; Yamamoto, Hideyuki; Asahina, Izumi

    2018-01-01

    The free gingival graft (FGG) and connective tissue graft (CTG) are currently considered to be the gold standards for keratinized gingival tissue reconstruction and augmentation. However, these procedures have some disadvantages in harvesting large grafts, such as donor-site morbidity as well as insufficient gingival width and thickness at the recipient site post-treatment. To solve these problems, we focused on an alternative strategy using micronized tissue transplantation (micro-graft). In this study, we first investigated whether transplantation of micronized gingival connective tissues (MGCTs) promotes skin wound healing. MGCTs (≤100 µm) were obtained by mincing a small piece (8 mm 3 ) of porcine keratinized gingiva using the RIGENERA system. The MGCTs were then transplanted to a full skin defect (5 mm in diameter) on the dorsal surface of immunodeficient mice after seeding to an atelocollagen matrix. Transplantations of atelocollagen matrixes with and without micronized dermis were employed as experimental controls. The results indicated that MGCTs markedly promote the vascularization and epithelialization of the defect area 14 days after transplantation compared to the experimental controls. After 21 days, complete wound closure with low contraction was obtained only in the MGCT grafts. Tracking analysis of transplanted MGCTs revealed that some mesenchymal cells derived from MGCTs can survive during healing and may function to assist in wound healing. We propose here that micro-grafting with MGCTs represents an alternative strategy for keratinized tissue reconstruction that is characterized by low morbidity and ready availability. © 2017 Wiley Periodicals, Inc.

  14. Bioactive glass in tissue engineering

    Science.gov (United States)

    Rahaman, Mohamed N.; Day, Delbert E.; Bal, B. Sonny; Fu, Qiang; Jung, Steven B.; Bonewald, Lynda F.; Tomsia, Antoni P.

    2011-01-01

    This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in biomaterials processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed. PMID:21421084

  15. Tissue-electronics interfaces: from implantable devices to engineered tissues

    Science.gov (United States)

    Feiner, Ron; Dvir, Tal

    2018-01-01

    Biomedical electronic devices are interfaced with the human body to extract precise medical data and to interfere with tissue function by providing electrical stimuli. In this Review, we outline physiologically and pathologically relevant tissue properties and processes that are important for designing implantable electronic devices. We summarize design principles for flexible and stretchable electronics that adapt to the mechanics of soft tissues, such as those including conducting polymers, liquid metal alloys, metallic buckling and meandering architectures. We further discuss technologies for inserting devices into the body in a minimally invasive manner and for eliminating them without further intervention. Finally, we introduce the concept of integrating electronic devices with biomaterials and cells, and we envision how such technologies may lead to the development of bionic organs for regenerative medicine.

  16. THE CHANGE OF TOTAL PROTEIN FRACTION OF MUSCLE TISSUE OF PORK WITH BIO- AND PHYSICO-CHEMICAL SPECIFIC IN THE PROCESS OF COOKING AT DIFFERENT TEMPERATURES

    Directory of Open Access Journals (Sweden)

    O. Shalimova

    2012-03-01

    Full Text Available The character of changes in total protein fraction of muscle tissue of pork with PSE defects in the process of cooking at temperatures ranging from 40 to 72 g.C in steps of 2 g.C is investigated. Our studies have revealed differences in the change of state the total fraction of muscle proteins with defects PSE pork during cooking.

  17. Translational Research in Pediatrics IV: Solid Tissue Collection and Processing.

    Science.gov (United States)

    Gillio-Meina, Carolina; Zielke, H Ronald; Fraser, Douglas D

    2016-01-01

    Solid tissues are critical for child-health research. Specimens are commonly obtained at the time of biopsy/surgery or postmortem. Research tissues can also be obtained at the time of organ retrieval for donation or from tissue that would otherwise have been discarded. Navigating the ethics of solid tissue collection from children is challenging, and optimal handling practices are imperative to maximize tissue quality. Fresh biopsy/surgical specimens can be affected by a variety of factors, including age, gender, BMI, relative humidity, freeze/thaw steps, and tissue fixation solutions. Postmortem tissues are also vulnerable to agonal factors, body storage temperature, and postmortem intervals. Nonoptimal tissue handling practices result in nucleotide degradation, decreased protein stability, artificial posttranslational protein modifications, and altered lipid concentrations. Tissue pH and tryptophan levels are 2 methods to judge the quality of solid tissue collected for research purposes; however, the RNA integrity number, together with analyses of housekeeping genes, is the new standard. A comprehensive clinical data set accompanying all tissue samples is imperative. In this review, we examined: the ethical standards relating to solid tissue procurement from children; potential sources of solid tissues; optimal practices for solid tissue processing, handling, and storage; and reliable markers of solid tissue quality. Copyright © 2016 by the American Academy of Pediatrics.

  18. Cryopreservation of tissue engineered constructs for bone.

    Science.gov (United States)

    Kofron, Michelle D; Opsitnick, Natalie C; Attawia, Mohamed A; Laurencin, Cato T

    2003-11-01

    The large-scale clinical use of tissue engineered constructs will require provisions for its mass availability and accessibility. Therefore, it is imperative to understand the effects of low temperature (-196 degrees C) on the tissue engineered biological system. Initial studies used samples of the osteoblast-like cell line (SaOS-2) adhered to a two-dimensional poly(lactide-co-glycolide) thin film (2D-PLAGA) or a three-dimensional poly(lactide-co-glycolide) sintered microsphere matrix (3D-PLAGA) designed for bone tissue engineering. Experimental samples were tested for their ability to maintain cell viability, following low temperature banking for one week, in solutions of the penetrating cryoprotective agents, dimethylsulfoxide (DMSO), ethylene glycol, and glycerol. Results indicated the DMSO solution yielded the greatest percent cell survival for SaOS-2 cells adhered to both the 2D- and 3D-PLAGA scaffolds; therefore, DMSO was used to cryopreserve mineralizing primary rabbit osteoblasts cells adhered to 2D-PLAGA matrices for 35 days. Results indicated retention of the extracellular matrix architecture as no statistically significant difference in the pre- and post-thaw mineralized structures was measured. Percent cell viability of the mineralized constructs following low temperature storage was approximately 50%. These are the first studies to address the issue of preservation techniques for tissue engineered constructs. The ability to successfully cryopreserve mineralized tissue engineered matrices for bone may offer an unlimited and readily available source of bone-like materials for orthopaedic applications.

  19. Synthetic biology meets tissue engineering.

    Science.gov (United States)

    Davies, Jamie A; Cachat, Elise

    2016-06-15

    Classical tissue engineering is aimed mainly at producing anatomically and physiologically realistic replacements for normal human tissues. It is done either by encouraging cellular colonization of manufactured matrices or cellular recolonization of decellularized natural extracellular matrices from donor organs, or by allowing cells to self-organize into organs as they do during fetal life. For repair of normal bodies, this will be adequate but there are reasons for making unusual, non-evolved tissues (repair of unusual bodies, interface to electromechanical prostheses, incorporating living cells into life-support machines). Synthetic biology is aimed mainly at engineering cells so that they can perform custom functions: applying synthetic biological approaches to tissue engineering may be one way of engineering custom structures. In this article, we outline the 'embryological cycle' of patterning, differentiation and morphogenesis and review progress that has been made in constructing synthetic biological systems to reproduce these processes in new ways. The state-of-the-art remains a long way from making truly synthetic tissues, but there are now at least foundations for future work. © 2016 Authors; published by Portland Press Limited.

  20. Bladder tissue engineering through nanotechnology.

    Science.gov (United States)

    Harrington, Daniel A; Sharma, Arun K; Erickson, Bradley A; Cheng, Earl Y

    2008-08-01

    The field of tissue engineering has developed in phases: initially researchers searched for "inert" biomaterials to act solely as replacement structures in the body. Then, they explored biodegradable scaffolds--both naturally derived and synthetic--for the temporary support of growing tissues. Now, a third phase of tissue engineering has developed, through the subcategory of "regenerative medicine." This renewed focus toward control over tissue morphology and cell phenotype requires proportional advances in scaffold design. Discoveries in nanotechnology have driven both our understanding of cell-substrate interactions, and our ability to influence them. By operating at the size regime of proteins themselves, nanotechnology gives us the opportunity to directly speak the language of cells, through reliable, repeatable creation of nanoscale features. Understanding the synthesis of nanoscale materials, via "top-down" and "bottom-up" strategies, allows researchers to assess the capabilities and limits inherent in both techniques. Urology research as a whole, and bladder regeneration in particular, are well-positioned to benefit from such advances, since our present technology has yet to reach the end goal of functional bladder restoration. In this article, we discuss the current applications of nanoscale materials to bladder tissue engineering, and encourage researchers to explore these interdisciplinary technologies now, or risk playing catch-up in the future.

  1. Radiosensitivity of soft tissue sarcomas

    International Nuclear Information System (INIS)

    Hirano, Toru; Iwasaki, Katsuro; Suzuki, Ryohei; Monzen, Yoshio; Hombo, Zenichiro

    1989-01-01

    The correlation between the effectiveness of radiation therapy and the histology of soft tissue sarcomas was investigated. Of 31 cases with a soft tissue sarcoma of an extremity treated by conservative surgery and postoperative radiation of 3,000-6,000 cGy, local recurrence occurred in 12; 5 out of 7 synovial sarcomas, 4 of 9 MFH, one of 8 liposarcomas, none of 4 rhabdomyosarcomas and 2 of 3 others. As for the histological subtyping, the 31 soft tissue sarcomas were divided into spindle cell, pleomorphic cell, myxoid and round cell type, and recurrence rates were 75%, 33.3%, 16.7% and 0%, respectively. From the remarkable difference in recurrent rate, it was suggested that round cell and myxoid type of soft tissue sarcomas showed a high radiosensitivity compared to the spindle cell type with low sensitivity. Clarifying the degree of radiosensitivity is helpful in deciding on the management of limb salvage in soft tissue sarcomas of an extremity. (author)

  2. Engineered Muscle Actuators: Cells and Tissues

    National Research Council Canada - National Science Library

    Dennis, Robert G; Herr, Hugh; Parker, Kevin K; Larkin, Lisa; Arruda, Ellen; Baar, Keith

    2007-01-01

    .... Our primary objectives were to engineer living skeletal muscle actuators in culture using integrated bioreactors to guide tissue development and to maintain tissue contractility, to achieve 50...

  3. Micro- and nanotechnology in cardiovascular tissue engineering

    International Nuclear Information System (INIS)

    Zhang Boyang; Xiao Yun; Hsieh, Anne; Thavandiran, Nimalan; Radisic, Milica

    2011-01-01

    While in nature the formation of complex tissues is gradually shaped by the long journey of development, in tissue engineering constructing complex tissues relies heavily on our ability to directly manipulate and control the micro-cellular environment in vitro. Not surprisingly, advancements in both microfabrication and nanofabrication have powered the field of tissue engineering in many aspects. Focusing on cardiac tissue engineering, this paper highlights the applications of fabrication techniques in various aspects of tissue engineering research: (1) cell responses to micro- and nanopatterned topographical cues, (2) cell responses to patterned biochemical cues, (3) controlled 3D scaffolds, (4) patterned tissue vascularization and (5) electromechanical regulation of tissue assembly and function.

  4. Optical clearing of vaginal tissues in cadavers

    Science.gov (United States)

    Chang, Chun-Hung; Hardy, Luke A.; Peters, Michael G.; Bastawros, Dina A.; Myers, Erinn M.; Kennelly, Michael J.; Fried, Nathaniel M.

    2018-02-01

    A nonsurgical laser procedure is being developed for treatment of female stress urinary incontinence (SUI). Previous studies in porcine vaginal tissues, ex vivo, as well as computer simulations, showed the feasibility of using near-infrared laser energy delivered through a transvaginal contact cooling probe to thermally remodel endopelvic fascia, while preserving the vaginal wall from thermal damage. This study explores optical properties of vaginal tissue in cadavers as an intermediate step towards future pre-clinical and clinical studies. Optical clearing of tissue using glycerol resulted in a 15-17% increase in optical transmission after 11 min at room temperature (and a calculated 32.5% increase at body temperature). Subsurface thermal lesions were created using power of 4.6 - 6.4 W, 5.2-mm spot, and 30 s irradiation time, resulting in partial preservation of vaginal wall to 0.8 - 1.1 mm depth.

  5. Beta adrenergic receptors in human cavernous tissue

    Energy Technology Data Exchange (ETDEWEB)

    Dhabuwala, C.B.; Ramakrishna, C.V.; Anderson, G.F.

    1985-04-01

    Beta adrenergic receptor binding was performed with /sup 125/I iodocyanopindolol on human cavernous tissue membrane fractions from normal tissue and transsexual procedures obtained postoperatively, as well as from postmortem sources. Isotherm binding studies on normal fresh tissues indicated that the receptor density was 9.1 fmoles/mg. with a KD of 23 pM. Tissue stored at room temperature for 4 to 6 hours, then at 4C in saline solution for 19 to 20 hours before freezing showed no significant changes in receptor density or affinity, and provided evidence for the stability of postmortem tissue obtained within the same time period. Beta receptor density of 2 cavernous preparations from transsexual procedures was not significantly different from normal control tissues, and showed that high concentrations of estrogen received by these patients had no effect on beta adrenergic receptor density. Displacement of /sup 125/iodocyanopindolol by 5 beta adrenergic agents demonstrated that 1-propranolol had the greatest affinity followed by ICI 118,551, zinterol, metoprolol and practolol. When the results of these displacement studies were subjected to Scatfit, non- linear regression line analysis, a single binding site was described. Based on the relative potency of the selective beta adrenergic agents it appears that these receptors were of the beta 2 subtype.

  6. Cryobanking of human ovarian tissue

    DEFF Research Database (Denmark)

    Ernst, Erik; Andersen, Anders Nyboe; Andersen, Claus Yding

    2014-01-01

    Cryopreservation of ovarian tissue is one way of preserving fertility in young women with a malignant disease or other disorders that require gonadotoxic treatment. The purpose of the study was to explore how many women remained interested in continued cryostorage of their ovarian tissue beyond...... an initial 5-year period. Between 1999 and 2006, a total of 201 girls and young women had one ovary cryopreserved for fertility preservation in Denmark. One hundred of these met our inclusion criteria, which included a follow-up period of at least 5 years, and were mailed a questionnaire. The response rate...... women with ovarian tissue cryobanked requested continued cryostorage after an initial period of at least 5 years. The main reason for requesting disposal was successful completion of a family....

  7. Tissue Friendly Pendulum: Soft Liner to prevent Tissue Irritation

    Directory of Open Access Journals (Sweden)

    Siddharth Shashidhar Revankar

    2014-01-01

    Full Text Available Palatal mucosal irritation is commonly encountered with the Pendulum appliance. The efficiency of soft liners in reducing tissue irritation has been well documented in the field of prosthodontics. The following article describes an innovative technique where soft liner can be used to reduce palatal mucosal irritation caused by pendulum appliance.

  8. Tissue properties and collagen remodeling in heart valve tissue engineering

    NARCIS (Netherlands)

    Geemen, van D.

    2012-01-01

    Valvular heart disease is a major health problem worldwide causing morbidity and mortality. Heart valve replacement is frequently applied to avoid serious cardiac, pulmonary, or systemic problems. However, the current replacements do not consist of living tissue and, consequently, cannot grow,

  9. Raman Spectroscopy of Ocular Tissue

    Science.gov (United States)

    Ermakov, Igor V.; Sharifzadeh, Mohsen; Gellermann, Warner

    The optically transparent nature of the human eye has motivated numerous Raman studies aimed at the non-invasive optical probing of ocular tissue components critical to healthy vision. Investigations include the qualitative and quantitative detection of tissue-specific molecular constituents, compositional changes occurring with development of ocular pathology, and the detection and tracking of ocular drugs and nutritional supplements. Motivated by a better understanding of the molecular mechanisms leading to cataract formation in the aging human lens, a great deal of work has centered on the Raman detection of proteins and water content in the lens. Several protein groups and the hydroxyl response are readily detectable. Changes of protein compositions can be studied in excised noncataractous tissue versus aged tissue preparations as well as in tissue samples with artificially induced cataracts. Most of these studies are carried out in vitro using suitable animal models and conventional Raman techniques. Tissue water content plays an important role in optimum light transmission of the outermost transparent ocular structure, the cornea. Using confocal Raman spectroscopy techniques, it has been possible to non-invasively measure the water to protein ratio as a measure of hydration status and to track drug-induced changes of the hydration levels in the rabbit cornea at various depths. The aqueous humor, normally supplying nutrients to cornea and lens, has an advantageous anterior location for Raman studies. Increasing efforts are pursued to non-invasively detect the presence of glucose and therapeutic concentrations of antibiotic drugs in this medium. In retinal tissue, Raman spectroscopy proves to be an important tool for research into the causes of macular degeneration, the leading cause of irreversible vision disorders and blindness in the elderly. It has been possible to detect the spectral features of advanced glycation and advanced lipooxydation end products in

  10. Commentary: Photothermal effects of laser tissue soldering

    International Nuclear Information System (INIS)

    Menovsky, T.; Beek, J.F.; Gemert, M.J.C. van

    1999-01-01

    Full text: Laser tissue welding is the process of using laser energy to join tissues without sutures or with a reduced number of sutures. Recently, diode lasers have been added to the list of fusion lasers (Lewis and Uribe 1993, Reali et al 1993). Typically, for tissue welding, deep penetrating diode lasers emitting at 800-810 nm are used, in combination with a strong absorbing protein solder containing the dye indocyanine green. Indocyanine green has a maximum absorption coefficient at 805 nm and binds preferentially with proteins (Sauda et al 1986). The greatest advantage of diode lasers is their compact size, easy use and low cost. In this issue of Physics in Medicine and Biology (pp 983-1002, 'Photothermal effects of laser tissue soldering'), in an in vitro study, McNally et al investigate the optimal laser settings and welding temperatures in relation to the tensile strength and thermal damage of bovine aorta specimens. An interesting statement in their introduction is that the low strength of laser produced anastomoses can lead to aneurysm formation. The increased chance of aneurysm formation may merely be due to the thermal effect of the laser on the vascular wall, especially on the adventitia and media layers, which become necrotic after thermal injury. Subsequent haemodynamic stress exerted on a damaged vascular wall is a significant contributing factor for aneurysmal initiation. Also interesting is the remark that 'by the application of wavelength-specific chromophores in tissue welding ... the requirement for precise focusing and aiming of the laser beam may be removed'. Though perhaps not yet fully justified, this statement, if true, would facilitate surgical procedures. While the experiments are conducted in a proper manner, the use of bovine aorta specimens, which were stored at -70 deg. C and subsequently thawed for the tissue welding experiments, may not be the most appropriate for studying tissue effects or tensile strength measurements, as the

  11. Biothermomechanical behavior of skin tissue

    Institute of Scientific and Technical Information of China (English)

    F.Xu; T.J.Lu; K.A.Seffen

    2008-01-01

    Advances in laser,microwave and similar tech nologies have led to recent developments of thermal treatments involving skin tissue.The effectiveness of these treatments is governed by the coupled thermal,mechanical,biological and neural responses of the affected tissue:a favorable interaction results in a procedure with relatively little pain and no lasting side effects.Currently,even though each behavioral facet is to a certain extent established and understood,none exists to date in the interdisciplinarv area.A highly interdisciplinary approach is required for studying the biothermomechanical behavior of skin,involving bioheat transfer.biomechanics and physiology.A comprehensive literature review penrtinent to the subject is presented in this paper,covering four subject areas:(a)skin structure,(b)skin bioheat transfer and thermal damage,(c)skin biomechanics,and(d)skin biothermomechanics.The major problems,issues,and topics for further studies are also outlined.This review finds that significant advances in each of these aspects have been achieved in recent years.Although focus is placed upon the biothermomechanical behavior of skin tissue,the fundamental concepts and methodologies reviewed in this paper may also be applicable for studying other soft tissues.

  12. Bone and soft tissue ischemia

    International Nuclear Information System (INIS)

    Berquist, T.H.; Brown, M.L.; Joyce, J.W.; Johnson, K.A.

    1989-01-01

    This paper discusses clinical features and imaging techniques for ischemic necrosis, a common problem in the foot, particularly in diabetics and patients with other vascular diseases. Necrosis of bone and soft tissues will be considered separately as the underlying etiology and imaging evaluation differ considerably

  13. Tissue dose in thorotrast patients

    International Nuclear Information System (INIS)

    Kaul, A.; Noffz, W.

    1978-01-01

    Absorbed doses to the liver, spleen, red marrow, lungs, kidneys, and to various parts of bone tissue were calculated for long-term burdens of intravascularly injected Thorotrast. The estimates were performed for typical injection levels of 10, 30, 50 and 100 ml, based upon best estimates of 232 Th tissue distribution, and steady state activity ratios between the subsequent daughters. Correcting for the α-particle self absorption within Thorotrast aggregates, the mean α-dose to a standard 70-kg man at 30 yr after the injection 0f 25 ml of Thorotrast is 750 rad to the liver, 2100 rad to the spleen, 270 rad to the red marrow, 60-620 rad in various parts of the lung, and 13 rad to the kidneys. Dose rates to various parts of bone tissue (bone surface, compact, and cancellous bone) were estimated by applying the ICRP model on alkaline earth metabolism to the continuous translocation of thorium daughters to bone and to the formation of thorium daughters by decay within bone tissue. The average dose to calcified bone from translocated 224 Ra with its daughters is 18 rad at 30 yr after the injection of 25 ml of Thorotrast. Considering the Spiess-Mays risk coefficient of 0.9-1.7% bone sarcoma/ 100 rad of average skeletal dose from 224 Ra and its daughters, the induction of 1.6-3.1 bone sarcomas per 1000 Thorotrast patients is predicted. (author)

  14. Biomaterials in myocardial tissue engineering

    Science.gov (United States)

    Reis, Lewis A.; Chiu, Loraine L. Y.; Feric, Nicole; Fu, Lara; Radisic, Milica

    2016-01-01

    Cardiovascular disease is the leading cause of death in the developed world, and as such there is a pressing need for treatment options. Cardiac tissue engineering emerged from the need to develop alternate sources and methods of replacing tissue damaged by cardiovascular diseases, as the ultimate treatment option for many who suffer from end-stage heart failure is a heart transplant. In this review we focus on biomaterial approaches to augment injured or impaired myocardium with specific emphasis on: the design criteria for these biomaterials; the types of scaffolds—composed of natural or synthetic biomaterials, or decellularized extracellular matrix—that have been used to develop cardiac patches and tissue models; methods to vascularize scaffolds and engineered tissue, and finally injectable biomaterials (hydrogels)designed for endogenous repair, exogenous repair or as bulking agents to maintain ventricular geometry post-infarct. The challenges facing the field and obstacles that must be overcome to develop truly clinically viable cardiac therapies are also discussed. PMID:25066525

  15. Epigenetics in plant tissue culture

    NARCIS (Netherlands)

    Smulders, M.J.M.; Klerk, de G.J.M.

    2011-01-01

    Plants produced vegetatively in tissue culture may differ from the plants from which they have been derived. Two major classes of off-types occur: genetic ones and epigenetic ones. This review is about epigenetic aberrations. We discuss recent studies that have uncovered epigenetic modifications at

  16. White adipose tissue: Getting nervous

    NARCIS (Netherlands)

    Fliers, E.; Kreier, F.; Voshol, P. J.; Havekes, L. M.; Sauerwein, H. P.; Kalsbeek, A.; Buijs, R. M.; Romijn, J. A.

    2003-01-01

    Neuroendocrine research has altered the traditional perspective of white adipose tissue (WAT) as a passive store of triglycerides. In addition to fatty acids, WAT produces many hormones and can therefore be designated as a traditional endocrine gland actively participating in the integrative

  17. Gastric tissue biopsy and culture

    Science.gov (United States)

    ... symptoms may include: Loss of appetite or weight loss Nausea and vomiting Pain in the upper part of the belly Black stools Vomiting blood or coffee ground-like material A gastric tissue biopsy and culture can help detect: Cancer Infections, most commonly Helicobacter ...

  18. Membrane supported scaffold architectures for tissue engineering

    NARCIS (Netherlands)

    Bettahalli Narasimha, M.S.

    2011-01-01

    Tissue engineering aims at restoring or regenerating a damaged tissue. Often the tissue recreation occurs by combining cells, derived from a patient biopsy, onto a 3D porous matrix, functioning as a scaffold. One of the current limitations of tissue engineering is the inability to provide sufficient

  19. Soft Tissue Sarcoma—Health Professional Version

    Science.gov (United States)

    Soft tissue sarcomas are malignant tumors that arise in any of the mesodermal tissues of the extremities, trunk and retroperitoneum, or head and neck. Soft tissue sarcomas may be heterogeneous. Find evidence-based information on soft tissue sarcoma treatment and research.

  20. The comparison of thermal tissue injuries caused by ultrasonic scalpel and electrocautery use in rabbit tongue tissue

    Science.gov (United States)

    Beriat, Guclu Kaan; Akmansu, Sefik Halit; Ezerarslan, Hande; Dogan, Cem; Han, Unsal; Saglam, Mehmet; Senel, Oytun Okan; Kocaturk, Sinan

    2012-01-01

    The aim of this study compares to the increase in tissue temperature and the thermal histological effects of ultrasonic scalpel, bipolar and unipolar electrosurgery incisions in the tongue tissue of rabbits. This study evaluates the histopathological changes related to thermal change and the maximum temperature values in the peripheral tissue brought about by the incisions carried out by the three methods in a comparative way. To assess thermal tissue damage induced by the three instruments, maximum tissue temperatures were measured during the surgical procedure and tongue tissue samples were examined histopathologically following the surgery. The mean maximum temperature values of the groups were 93.93±2.76 C° for the unipolar electrocautery group, whereas 85.07±5.95 C° for the bipolar electrocautery group, and 108.23±7.64 C° for the ultrasonic scalpel group. There was a statistically significant relationship between the increase in maximum temperature values and the separation among tissue layers, edema, congestion, necrosis, hemorrhage, destruction in blood vessel walls and fibrin accumulation, and between the existence of fibrin thrombus and tissue damage depth (pelectrocautery use gives way to less temperature increase in the tissues and less thermal tissue damage in comparison to the other methods. PMID:22938541

  1. Soft tissue modelling with conical springs.

    Science.gov (United States)

    Omar, Nadzeri; Zhong, Yongmin; Jazar, Reza N; Subic, Aleksandar; Smith, Julian; Shirinzadeh, Bijan

    2015-01-01

    This paper presents a new method for real-time modelling soft tissue deformation. It improves the traditional mass-spring model with conical springs to deal with nonlinear mechanical behaviours of soft tissues. A conical spring model is developed to predict soft tissue deformation with reference to deformation patterns. The model parameters are formulated according to tissue deformation patterns and the nonlinear behaviours of soft tissues are modelled with the stiffness variation of conical spring. Experimental results show that the proposed method can describe different tissue deformation patterns using one single equation and also exhibit the typical mechanical behaviours of soft tissues.

  2. A portrait of tissue phosphoprotein stability in the clinical tissue procurement process.

    Science.gov (United States)

    Espina, Virginia; Edmiston, Kirsten H; Heiby, Michael; Pierobon, Mariaelena; Sciro, Manuela; Merritt, Barbara; Banks, Stacey; Deng, Jianghong; VanMeter, Amy J; Geho, David H; Pastore, Lucia; Sennesh, Joel; Petricoin, Emanuel F; Liotta, Lance A

    2008-10-01

    Little is known about the preanalytical fluctuations of phosphoproteins during tissue procurement for molecular profiling. This information is crucial to establish guidelines for the reliable measurement of these analytes. To develop phosphoprotein profiles of tissue subjected to the trauma of excision, we measured the fidelity of 53 signal pathway phosphoproteins over time in tissue specimens procured in a community clinical practice. This information provides strategies for potential surrogate markers of stability and the design of phosphoprotein preservative/fixation solutions. Eleven different specimen collection time course experiments revealed augmentation (+/-20% from the time 0 sample) of signal pathway phosphoprotein levels as well as decreases over time independent of tissue type, post-translational modification, and protein subcellular location (tissues included breast, colon, lung, ovary, and uterus (endometrium/myometrium) and metastatic melanoma). Comparison across tissue specimens showed an >20% decrease of protein kinase B (AKT) Ser-473 (p 20% increases within 90-min postprocurement. Endothelial nitric-oxide synthase Ser-1177 did not change over the time period evaluated with breast or leiomyoma tissue. Treatment with phosphatase or kinase inhibitors alone revealed that tissue kinase pathways are active ex vivo. Combinations of kinase and phosphatase inhibitors appeared to stabilize proteins that exhibited increases in the presence of phosphatase inhibitors alone (ATF-2 Thr-71, SAPK/JNK Thr-183/Tyr-185, STAT1 Tyr-701, JAK1 Tyr-1022/1023, and PAK1/PAK2 Ser-199/204/192/197). This time course study 1) establishes the dynamic nature of specific phosphoproteins in excised tissue, 2) demonstrates augmented phosphorylation in the presence of phosphatase inhibitors, 3) shows that kinase inhibitors block the upsurge in phosphorylation of phosphoproteins, 4) provides a rational strategy for room temperature preservation of proteins, and 5) constitutes a

  3. Biomechanics and mechanobiology in functional tissue engineering

    Science.gov (United States)

    Guilak, Farshid; Butler, David L.; Goldstein, Steven A.; Baaijens, Frank P.T.

    2014-01-01

    The field of tissue engineering continues to expand and mature, and several products are now in clinical use, with numerous other preclinical and clinical studies underway. However, specific challenges still remain in the repair or regeneration of tissues that serve a predominantly biomechanical function. Furthermore, it is now clear that mechanobiological interactions between cells and scaffolds can critically influence cell behavior, even in tissues and organs that do not serve an overt biomechanical role. Over the past decade, the field of “functional tissue engineering” has grown as a subfield of tissue engineering to address the challenges and questions on the role of biomechanics and mechanobiology in tissue engineering. Originally posed as a set of principles and guidelines for engineering of load-bearing tissues, functional tissue engineering has grown to encompass several related areas that have proven to have important implications for tissue repair and regeneration. These topics include measurement and modeling of the in vivo biomechanical environment; quantitative analysis of the mechanical properties of native tissues, scaffolds, and repair tissues; development of rationale criteria for the design and assessment of engineered tissues; investigation of the effects biomechanical factors on native and repair tissues, in vivo and in vitro; and development and application of computational models of tissue growth and remodeling. Here we further expand this paradigm and provide examples of the numerous advances in the field over the past decade. Consideration of these principles in the design process will hopefully improve the safety, efficacy, and overall success of engineered tissue replacements. PMID:24818797

  4. Tissue physiology and the response to heat

    DEFF Research Database (Denmark)

    Horsman, Michael Robert

    2006-01-01

    physiological effects should occur in normal tissues, such combination therapies must be carefully applied. Heating tumours to higher temperatures typically causes a transient increase in perfusion during heating, followed by vascular collapse which if sufficient will increase tumour necrosis. The speed...... and degree of vascular collapse is dependent on heating time, temperature and tumour model used. Such vascular collapse generally occurs at temperatures that cause a substantial blood flow increase in certain normal tissues, thus preferential anti-tumour effects can be achieved. The tumour vascular supply...... can also be exploited to improve the response to heat. Decreasing blood flow, using transient physiological modifiers or longer acting vascular disrupting agents prior to the initiation of heating, can both increase the accumulation of physical heat in the tumour, as well as increase heat sensitivity...

  5. Skin color and tissue thickness effects on transmittance, reflectance, and skin temperature when using 635 and 808 nm lasers in low intensity therapeutics.

    Science.gov (United States)

    Souza-Barros, Leanna; Dhaidan, Ghaith; Maunula, Mikko; Solomon, Vaeda; Gabison, Sharon; Lilge, Lothar; Nussbaum, Ethne L

    2018-04-01

    To examine the role of skin color and tissue thickness on transmittance, reflectance, and skin heating using red and infrared laser light. Forty volunteers were measured for skin color and skin-fold thickness at a standardized site near the elbow. Transmittance, reflectance and skin temperature were recorded for energy doses of 2, 6, 9, and 12 Joules using 635 nm (36 mW) and 808 nm (40 mW) wavelength laser diodes with irradiances within American National Standards Institute safety guidelines (4.88 mm diameter, 0.192 W/cm 2 and 4.88 mm diameter, 0.214 W/cm 2 , respectively). The key factors affecting reflectance to an important degree were skin color and wavelength. However, the skin color effects were different for the two wavelengths: reflectance decreased for darker skin with a greater decrease for red light than near infrared light. Transmittance was greater using 808 nm compared with 635 nm. However, the effect was partly lost when the skin was dark rather than light, and was increasingly lost as tissue thickness increased. Dose had an increasing effect on temperature (0.7-1.6°C across the 6, 9, and 12 J doses); any effects of wavelength, skin color, and tissue thickness were insignificant compared to dose effects. Subjects themselves were not aware of the increased skin temperature. Transmittance and reflectance changes as a function of energy were very small and likely of no clinical significance. Absorption did not change with higher energy doses and increasing temperature. Skin color and skin thickness affect transmittance and reflectance of laser light and must be accounted for when selecting energy dose to ensure therapeutic effectiveness at the target tissue. Skin heating appears not to be a concern when using 635 and 808 nm lasers at energy doses of up to 12 J and irradiance within American National Standards Institute standards. Photobiomodulation therapy should never exceed the American National Standards Institute

  6. Periodontal tissue damage in smokers

    Directory of Open Access Journals (Sweden)

    Hutojo Djajakusuma

    2006-09-01

    Full Text Available Dental plaque is the primary etiological factor in periodontal diseases. However, there are many factors that can modify how an individual periodontal tissue will respond to the accumulation of dental plaque. Among such risk factors, there is increasing evidence that smoking tobacco products alters the expression and rate of progression of periodontal diseases. The aim of this study was to find out the loss of periodontal tissue adhesion in smokers by measuring pocket depth using probe, and by measuring alveolar bone damage using Bone Loss Score (BLS radiographic methods on teeth 12, 11, 21, 22, 32, 31, 41, 42. Based on T Test statistical analysis, there were significant differences in pocket depth damage of alveolar bone in smokers and non smokers. In conclusion there were increasing pocket depth and alveolar bone damage in smokers.

  7. Collagen Quantification in Tissue Specimens.

    Science.gov (United States)

    Coentro, João Quintas; Capella-Monsonís, Héctor; Graceffa, Valeria; Wu, Zhuning; Mullen, Anne Maria; Raghunath, Michael; Zeugolis, Dimitrios I

    2017-01-01

    Collagen is the major extracellular protein in mammals. Accurate quantification of collagen is essential in the biomaterials (e.g., reproducible collagen scaffold fabrication), drug discovery (e.g., assessment of collagen in pathophysiologies, such as fibrosis), and tissue engineering (e.g., quantification of cell-synthesized collagen) fields. Although measuring hydroxyproline content is the most widely used method to quantify collagen in biological specimens, the process is very laborious. To this end, the Sircol™ Collagen Assay is widely used due to its inherent simplicity and convenience. However, this method leads to overestimation of collagen content due to the interaction of Sirius red with basic amino acids of non-collagenous proteins. Herein, we describe the addition of an ultrafiltration purification step in the process to accurately determine collagen content in tissues.

  8. Photon Entanglement Through Brain Tissue.

    Science.gov (United States)

    Shi, Lingyan; Galvez, Enrique J; Alfano, Robert R

    2016-12-20

    Photon entanglement, the cornerstone of quantum correlations, provides a level of coherence that is not present in classical correlations. Harnessing it by study of its passage through organic matter may offer new possibilities for medical diagnosis technique. In this work, we study the preservation of photon entanglement in polarization, created by spontaneous parametric down-conversion, after one entangled photon propagates through multiphoton-scattering brain tissue slices with different thickness. The Tangle-Entropy (TS) plots show the strong preservation of entanglement of photons propagating in brain tissue. By spatially filtering the ballistic scattering of an entangled photon, we find that its polarization entanglement is preserved and non-locally correlated with its twin in the TS plots. The degree of entanglement correlates better with structure and water content than with sample thickness.

  9. Postgraduate programme in tissue banking

    International Nuclear Information System (INIS)

    Yongyudh Vajaradul

    1999-01-01

    In 1992 in the Project Formulation Meeting of IAEA, the masters degree programme was proposed by Dr. Youngyudh Vajaradul, Thailand to upgrade the personnel of tissue bank and the person who had been working and involving in tissue banking. After The Bangkok Biomaterial Center proposed the degree programme and presented to Mahidol University, this programme was accepted by Ministry of University Affairs in 1998 and the masters degree programme under the name of 'Masters of Science in Biomaterial for Implantation' will be started in April 1999. IAEA will support the fellowship candidates from the region to study in masters degree programme. The programme includes 6 months of course work in Bangkok that is 12 credits and 24 is for the dissertation work which would be done in any country. The time of validity is 5 years

  10. Quality assurance in tissue banking

    International Nuclear Information System (INIS)

    Von Versen, R.; Mnig, H. J.; Bettin, D.

    1999-01-01

    Today the different kinds of human allografts have the full acceptance for the clinical application for the treatment of a very wide range of indications in many medical disciplines. An essential aspect of this acceptance of these allografts is the complete biological safety, first of all the exclusion of virus contaminations. The German Institute for Cell and Tissue Replacement (DIZG) is functioning as a national tissue bank cooperating with more than 300 hospitals in Germany and Austria. Its profile is determined by the processing of tissue allografts like cortical and cancellous bone, fascia lata, tendon as well as skin, skin substitutes and cultured autologous and allogenic kerytinocytes. DIZG is licensed by the German Federal Institute for Pharmaceuticals and Medical Products and the country health authorities. To ensure that the allografts fulfill the highest quality requirements a controlled and certified quality management system has been established. In accordance with the Good Manufacturing Practice all procedures are perform-ned on the basis of validated methods. All non-vital allografts are sterilized by a chemical sterilisation method with peracetic acid (PAA) that is validated by the Robert Koch Institute, an independent governmental institution, for the inactivation of bacteria, fungi and viruses. The used test viruses are Pseudorabies V, Polio V, Bovine Virusdiarrhoe V, Parvo V, Hepatitis A V, HIV). The DIZG quality management system (QMS) is based on ISO 9001 which is required for institutions that are involved in processing, research and education and is certified by an international auditing body. With this presentation the validation design shall be introduced and the responsibility of regional and national tissue banks for internal and external quality control and quality assurance shall be discussed

  11. Endoscopic tissue diagnosis of cholangiocarcinoma.

    LENUS (Irish Health Repository)

    Harewood, Gavin C

    2008-09-01

    The extremely poor outcome in patients with cholangiocarcinoma, in large part, reflects the late presentation of these tumors and the challenging nature of establishing a tissue diagnosis. Establishing a diagnosis of cholangiocarcinoma requires obtaining evidence of malignancy from sampling of the epithelium of the biliary tract, which has proven to be challenging. Although endoscopic ultrasound-guided fine needle aspiration performs slightly better than endoscopic retrograde cholangiopancreatography in diagnosing cholangiocarcinoma, both endoscopic approaches demonstrate disappointing performance characteristics.

  12. [Tissue-specific nucleoprotein complexes].

    Science.gov (United States)

    Riadnova, I Iu; Shataeva, L K; Khavinson, V Kh

    2000-01-01

    A method of isolation of native nucleorprotein complexes from cattle cerebral cortex, thymus, and liver was developed. Compositions of these complexes were studied by means of gel-chromatography and ion-exchange chromatography. These preparations were shown to consist of several fractions of proteins and their complexes differ by molecular mass and electro-chemical properties. Native nucleoprotein complexes revealed high tissue specific activity, which was not species-specific.

  13. Biotransformations with plant tissue cultures.

    Science.gov (United States)

    Carew, D P; Bainbridge, T

    1976-01-01

    Suspension cultures of Catharanthus roseus, Apocynum cannabinum and Conium maculatum were examined for their capacity to transform aniline, anisole, acetanilide, benzoic acid and coumarin. None of the cultures transformed acetanilide but each produced acetanilide when fed aniline. All three cultures converted benzoic acid to its para-hydroxy derivative. Coumarin was selectively hydroxylated at the 7-position by Catharanthus and Conium and anisole was O-demethylated only by older Catharanthus tissue.

  14. Titanium-hydroxyapatite composites sintered at low temperature for tissue engineering: in vitro cell support and biocompatibility.

    Science.gov (United States)

    Comín, Romina; Cid, Mariana P; Grinschpun, Luciano; Oldani, Carlos; Salvatierra, Nancy A

    2017-04-26

    In clinical orthopedics, a critical problem is the bone tissue loss produced by a disease or injury. The use of composites from titanium and hydroxyapatite for biomedical applications has increased due to the resulting advantageous combination of hydroxyapatite bioactivity and favorable mechanical properties of titanium. Powder metallurgy is a simple and lower-cost method that uses powder from titanium and hydroxyapatite to obtain composites having hydroxyapatite phases in a metallic matrix. However, this method has certain limitations arising from thermal decomposition of hydroxyapatite in the titanium-hydroxyapatite system above 800°C. We obtained a composite from titanium and bovine hydroxyapatite powders sintered at 800°C and evaluated its bioactivity and cytocompatibility according to the ISO 10993 standard. Surface analysis and bioactivity of the composite was evaluated by X-ray diffraction and SEM. MTT assay was carried out to assess cytotoxicity on Vero and NIH3T3 cells. Cell morphology and cell adhesion on the composite surface were analyzed using fluorescence and SEM. We obtained a porous composite with hydroxyapatite particles well integrated in titanium matrix which presented excellent bioactivity. Our data did not reveal any toxicity of titanium-hydroxyapatite composite on Vero or NIH3T3 cells. Moreover, extracts from composite did not affect cell morphology or density. Finally, NIH3T3 cells were capable of adhering to and proliferating on the composite surface. The composite obtained displayed promising biomedical applications through the simple method of powder metallurgy. Additionally, these findings provide an in vitro proof for adequate biocompatibility of titanium-hydroxyapatite composite sintered at 800°C.

  15. Silk fibroin in tissue engineering.

    Science.gov (United States)

    Kasoju, Naresh; Bora, Utpal

    2012-07-01

    Tissue engineering (TE) is a multidisciplinary field that aims at the in vitro engineering of tissues and organs by integrating science and technology of cells, materials and biochemical factors. Mimicking the natural extracellular matrix is one of the critical and challenging technological barriers, for which scaffold engineering has become a prime focus of research within the field of TE. Amongst the variety of materials tested, silk fibroin (SF) is increasingly being recognized as a promising material for scaffold fabrication. Ease of processing, excellent biocompatibility, remarkable mechanical properties and tailorable degradability of SF has been explored for fabrication of various articles such as films, porous matrices, hydrogels, nonwoven mats, etc., and has been investigated for use in various TE applications, including bone, tendon, ligament, cartilage, skin, liver, trachea, nerve, cornea, eardrum, dental, bladder, etc. The current review extensively covers the progress made in the SF-based in vitro engineering and regeneration of various human tissues and identifies opportunities for further development of this field. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Nanoparticles for bone tissue engineering.

    Science.gov (United States)

    Vieira, Sílvia; Vial, Stephanie; Reis, Rui L; Oliveira, J Miguel

    2017-05-01

    Tissue engineering (TE) envisions the creation of functional substitutes for damaged tissues through integrated solutions, where medical, biological, and engineering principles are combined. Bone regeneration is one of the areas in which designing a model that mimics all tissue properties is still a challenge. The hierarchical structure and high vascularization of bone hampers a TE approach, especially in large bone defects. Nanotechnology can open up a new era for TE, allowing the creation of nanostructures that are comparable in size to those appearing in natural bone. Therefore, nanoengineered systems are now able to more closely mimic the structures observed in naturally occurring systems, and it is also possible to combine several approaches - such as drug delivery and cell labeling - within a single system. This review aims to cover the most recent developments on the use of different nanoparticles for bone TE, with emphasis on their application for scaffolds improvement; drug and gene delivery carriers, and labeling techniques. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:590-611, 2017. © 2017 American Institute of Chemical Engineers.

  17. Implications of human tissue studies

    International Nuclear Information System (INIS)

    Kathren, R.L.

    1986-10-01

    Through radiochemical analysis of voluntary tissue donations, the United States Transuranium and Uranium Registries are gaining improved understanding of the distribution and biokinetics of actinide elements in occupationally exposed persons. Evaluation of the first two whole body contributions to the Transuranium Registry revealed an inverse proportionality between actinide concentration and bone ash fraction. The analysis of a whole body with a documented 241 Am deposition indicated a significantly shorter half-time in liver and a greater fraction resident in the skeleton than predicted by existing models. Other studies of the Registries are designed to evaluate in vivo estimates of actinide deposition with those derived from postmortem tissue analysis, compare results of animal experiments with human data, and reviw histopathologic slides for tissue toxicity that might be attributable to exposure to uranium and the transuranic elements. The implications of these recent findings and other work of the Registries are discussed from the standpoint of their potential impact on biokinetic modeling, internal dose assessment, safety standards, and operational health physics practices

  18. Monitoring of tissue optical properties during thermal coagulation of ex vivo tissues.

    Science.gov (United States)

    Nagarajan, Vivek Krishna; Yu, Bing

    2016-09-01

    Real-time monitoring of tissue status during thermal ablation of tumors is critical to ensure complete destruction of tumor mass, while avoiding tissue charring and excessive damage to normal tissues. Currently, magnetic resonance thermometry (MRT), along with magnetic resonance imaging (MRI), is the most commonly used technique for monitoring and assessing thermal ablation process in soft tissues. MRT/MRI is very expensive, bulky, and often subject to motion artifacts. On the other hand, light propagation within tissue is sensitive to changes in tissue microstructure and physiology which could be used to directly quantify the extent of tissue damage. Furthermore, optical monitoring can be a portable, and cost-effective alternative for monitoring a thermal ablation process. The main objective of this study, is to establish a correlation between changes in tissue optical properties and the status of tissue coagulation/damage during heating of ex vivo tissues. A portable diffuse reflectance spectroscopy system and a side-firing fiber-optic probe were developed to study the absorption (μa (λ)), and reduced scattering coefficients (μ's (λ)) of native and coagulated ex vivo porcine, and chicken breast tissues. In the first experiment, both porcine and chicken breast tissues were heated at discrete temperature points between 24 and 140°C for 2 minutes. Diffuse reflectance spectra (430-630 nm) of native and coagulated tissues were recorded prior to, and post heating. In a second experiment, porcine tissue samples were heated at 70°C and diffuse reflectance spectra were recorded continuously during heating. The μa (λ) and μ's (λ) of the tissues were extracted from the measured diffuse reflectance spectra using an inverse Monte-Carlo model of diffuse reflectance. Tissue heating was stopped when the wavelength-averaged scattering plateaued. The wavelength-averaged optical properties, and , for native porcine tissues (n = 66) at room temperature, were 5.4

  19. Hematopoietic stem cell origin of connective tissues.

    Science.gov (United States)

    Ogawa, Makio; Larue, Amanda C; Watson, Patricia M; Watson, Dennis K

    2010-07-01

    Connective tissue consists of "connective tissue proper," which is further divided into loose and dense (fibrous) connective tissues and "specialized connective tissues." Specialized connective tissues consist of blood, adipose tissue, cartilage, and bone. In both loose and dense connective tissues, the principal cellular element is fibroblasts. It has been generally believed that all cellular elements of connective tissue, including fibroblasts, adipocytes, chondrocytes, and bone cells, are generated solely by mesenchymal stem cells. Recently, a number of studies, including those from our laboratory based on transplantation of single hematopoietic stem cells, strongly suggested a hematopoietic stem cell origin of these adult mesenchymal tissues. This review summarizes the experimental evidence for this new paradigm and discusses its translational implications. Copyright 2010 ISEH - Society for Hematology and Stem Cells. All rights reserved.

  20. Dental tissue as a thermoluminescence dosimetry dosimeter

    International Nuclear Information System (INIS)

    Solaimani, F.; Zahmatkesh, M.H.; Akhlaghpoor, Sh.

    2003-01-01

    Background: Thermoluminescence dosimetry is one of the dosimetry procedures used widely as routine and personal dosimeters. In order to extend this kind of dosimeters, dental tissue has been examined and was found promising as a Thermoluminescence Dosimetry dosimeter. Materials and Methods: In this study, 70 health teeth were collected. The only criterion, wich was considered for selection of the teeth, was the healthiness of them regardless of age and gender of the donors. All collected samples were washed and cleaned and milled uniformly. The final powder had a uniform grain size between 100-300 micrometer. The sample was divided into four groups. Group A and B were used for measurement of density and investigation of variation of thermoluminescent characteristics with temperature respectively. Groups C and D were used for investigation of variation of thermoluminescent intensity with dose and fading of this intensity with time. In all cases the results obtained with dental tissue were compared to a standard LiF, thermoluminescence dosimetry dosimeter. Results: It was found that, average density of the dental tissue was 1.570 g/cm 3 , which is comparable to density of LiF, which is 1.612g/cm 3 . It was also concluded that the range of 0-300 d ig C , dental tissue has a simple curve with two specific peaks at 140 and 25 d ig C respectively. The experiment also showed that, the variation of relative intensity versus dose is linear in the range of 0.04-0.1 Gy. The fading rate of dental tissue is higher than LiF but still in the acceptable range (14% per month in compare to 5.2% per month). Conclusion: Dental tissue as a natural dosimeter is comparable with Thermoluminescence Dosimetry and can be used in accidental events with a good approximation

  1. Monkey alcohol tissue research resource: banking tissues for alcohol research.

    Science.gov (United States)

    Daunais, James B; Davenport, April T; Helms, Christa M; Gonzales, Steven W; Hemby, Scott E; Friedman, David P; Farro, Jonathan P; Baker, Erich J; Grant, Kathleen A

    2014-07-01

    An estimated 18 million adults in the United States meet the clinical criteria for diagnosis of alcohol abuse or alcoholism, a disorder ranked as the third leading cause of preventable death. In addition to brain pathology, heavy alcohol consumption is comorbid with damage to major organs including heart, lungs, liver, pancreas, and kidneys. Much of what is known about risk for and consequences of heavy consumption derive from rodent or retrospective human studies. The neurobiological effects of chronic intake in rodent studies may not easily translate to humans due to key differences in brain structure and organization between species, including a lack of higher-order cognitive functions, and differences in underlying prefrontal cortical neural structures that characterize the primate brain. Further, rodents do not voluntarily consume large quantities of ethanol (EtOH) and they metabolize it more rapidly than primates. The basis of the Monkey Alcohol Tissue Research Resource (MATRR) is that nonhuman primates, specifically monkeys, show a range of drinking excessive amounts of alcohol (>3.0 g/kg or a 12 drink equivalent per day) over long periods of time (12 to 30 months) with concomitant pathological changes in endocrine, hepatic, and central nervous system (CNS) processes. The patterns and range of alcohol intake that monkeys voluntarily consume parallel what is observed in humans with alcohol use disorders and the longitudinal experimental design spans stages of drinking from the EtOH-naïve state to early exposure through chronic abuse. Age- and sex-matched control animals self-administer an isocaloric solution under identical operant procedures. The MATRR is a unique postmortem tissue bank that provides CNS and peripheral tissues, and associated bioinformatics from monkeys that self-administer EtOH using a standardized experimental paradigm to the broader alcohol research community. This resource provides a translational platform from which we can better

  2. Effect of ionizing radiations on connective tissue

    International Nuclear Information System (INIS)

    Altman, K.I.; Gerber, G.B.

    1980-01-01

    The effects of ionizing radiations on connective tissue in lung, heart, vasculature, kidney, skin, and skeletal tissues are reviewed. Special emphasis is given to the effect of ionizing radiations on vasculo-connective tissue and fibrotic changes following radiation-induced injury to organs and tissues. In order to put the subject matter in proper prospective, the general biochemistry, physiology, and pathology of connective tissue is reviewed briefly together with the participation of connective tissue in disease. The review closes with an assessment of future problems and an enumeration and discussion of important, as yet unanswered questions

  3. Responsiveness to Thyroid Hormone and to Ambient Temperature Underlies Differences Between Brown Adipose Tissue and Skeletal Muscle Thermogenesis in a Mouse Model of Diet-Induced Obesity

    Science.gov (United States)

    Ueta, Cintia B.; Olivares, Emerson L.

    2011-01-01

    Thyroid hormone accelerates energy expenditure (EE) and is critical for cold-induced thermogenesis. To define the metabolic role played by thyroid hormone in the dissipation of calories from diet, hypothyroid mice were studied for 60 d in a comprehensive lab animal monitoring system. Hypothyroidism decreased caloric intake and body fat while down-regulating genes in the skeletal muscle but not brown adipose tissue thermogenic programs, without affecting daily EE. Only at thermoneutrality (30 C) did hypothyroid mice exhibit slower rate of EE, indicating a metabolic response to hypothyroidism that depends on ambient temperature. A byproduct of this mechanism is that at room temperature (22 C), hypothyroid mice are protected against diet-induced obesity, i.e. only at thermoneutrality did hypothyroid mice become obese when placed on a high-fat diet (HFD). This is in contrast to euthyroid controls, which on a HFD gained more body weight and fat at any temperature while activating the brown adipose tissue and accelerating daily EE but not the skeletal muscle thermogenic program. In the liver of euthyroid controls, HFD caused an approximately 5-fold increase in triglyceride content and expression of key metabolic genes, whereas acclimatization to 30 C cut triglyceride content by half and normalized gene expression. However, in hypothyroid mice, HFD-induced changes in liver persisted at 30 C, resulting in marked liver steatosis. Acclimatization to thermoneutrality dramatically improves glucose homeostasis, but this was not affected by hypothyroidism. In conclusion, hypothyroid mice are metabolically sensitive to environmental temperature, constituting a mechanism that defines resistance to diet-induced obesity and hepatic lipid metabolism. PMID:21771890

  4. Tissue culture of ornamental cacti

    Directory of Open Access Journals (Sweden)

    Eugenio Pérez-Molphe-Balch

    2015-12-01

    Full Text Available Cacti species are plants that are well adapted to growing in arid and semiarid regions where the main problem is water availability. Cacti have developed a series of adaptations to cope with water scarcity, such as reduced leaf surface via morphological modifications including spines, cereous cuticles, extended root systems and stem tissue modifications to increase water storage, and crassulacean acid metabolism to reduce transpiration and water loss. Furthermore, seeds of these plants very often exhibit dormancy, a phenomenon that helps to prevent germination when the availability of water is reduced. In general, cactus species exhibit a low growth rate that makes their rapid propagation difficult. Cacti are much appreciated as ornamental plants due to their great variety and diversity of forms and their beautiful short-life flowers; however, due to difficulties in propagating them rapidly to meet market demand, they are very often over-collected in their natural habitats, which leads to numerous species being threatened, endangered or becoming extinct. Therefore, plant tissue culture techniques may facilitate their propagation over a shorter time period than conventional techniques used for commercial purposes; or may help to recover populations of endangered or threatened species for their re-introduction in the wild; or may also be of value to the preservation and conservation of the genetic resources of this important family. Herein we present the state-of-the-art of tissue culture techniques used for ornamental cacti and selected suggestions for solving a number of the problems faced by members of the Cactaceae family.

  5. NMR imaging of cell phone radiation absorption in brain tissue

    Science.gov (United States)

    Gultekin, David H.; Moeller, Lothar

    2013-01-01

    A method is described for measuring absorbed electromagnetic energy radiated from cell phone antennae into ex vivo brain tissue. NMR images the 3D thermal dynamics inside ex vivo bovine brain tissue and equivalent gel under exposure to power and irradiation time-varying radio frequency (RF) fields. The absorbed RF energy in brain tissue converts into Joule heat and affects the nuclear magnetic shielding and the Larmor precession. The resultant temperature increase is measured by the resonance frequency shift of hydrogen protons in brain tissue. This proposed application of NMR thermometry offers sufficient spatial and temporal resolution to characterize the hot spots from absorbed cell phone radiation in aqueous media and biological tissues. Specific absorption rate measurements averaged over 1 mg and 10 s in the brain tissue cover the total absorption volume. Reference measurements with fiber optic temperature sensors confirm the accuracy of the NMR thermometry. PMID:23248293

  6. Fundamentals of bladder tissue engineering | Mahfouz | African ...

    African Journals Online (AJOL)

    Fundamentals of bladder tissue engineering. ... could affect the bladder and lead to eventual loss of its integrity, with the need for replacement or repair. ... Tissue engineering relies upon three essential pillars; the scaffold, the cells seeded on ...

  7. Fibrovascular tissue in bilateral juxtafoveal telangiectasis.

    Science.gov (United States)

    Park, D; Schatz, H; McDonald, H R; Johnson, R N

    1996-09-01

    To study the natural history and retinal findings associated with the intraretinal and subretinal fibrovascular tissues that develop in the late phases of bilateral juxtafoveal telangiectasis. The records of 10 patients (11 eyes) with bilateral juxtafoveal telangiectasis who developed these fibrovascular tissues were examined. Throughout the follow-up period (average 44 months), only 2 eyes (18%) lost 2 or more lines of vision; the final visual acuities were similar for the eyes both with and without fibrovascular tissues. Sixty-four percent of fibrovascular tissues showed little to no growth. Eyes with fibrovascular tissue commonly had retinal pigment epithelial hyperplasia (72%), draining retinal venules (82%), and retinal vascular distortion (64%). Fibrovascular tissues of bilateral juxtafoveal telangiectasis have little proliferative potential and minimal effects on visual acuity. Nevertheless, these fibrovascular tissues do remodel over time, leading to retinal vascular distortion. Given these benign findings, the role of laser photocoagulation treatment of these tissues is questionable.

  8. Donation FAQs (Bone and Tissue Allografts)

    Science.gov (United States)

    ... Biologics is affiliated with organ, eye and tissue procurement agencies throughout the U.S. They typically ... Visit DonateLife.net and learn how your gift of tissue can give bring new life to ...

  9. SE Marine Mammal Histology/Tissue data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples are collected from stranded marine mammals in the Southeastern United States. These tissue samples are examined histologically and evaluated to...

  10. RF safety assessment of a bilateral four-channel transmit/receive 7 Tesla breast coil: SAR versus tissue temperature limits.

    Science.gov (United States)

    Fiedler, Thomas M; Ladd, Mark E; Bitz, Andreas K

    2017-01-01

    The purpose of this work was to perform an RF safety evaluation for a bilateral four-channel transmit/receive breast coil and to determine the maximum permissible input power for which RF exposure of the subject stays within recommended limits. The safety evaluation was done based on SAR as well as on temperature simulations. In comparison to SAR, temperature is more directly correlated with tissue damage, which allows a more precise safety assessment. The temperature simulations were performed by applying three different blood perfusion models as well as two different ambient temperatures. The goal was to evaluate whether the SAR and temperature distributions correlate inside the human body and whether SAR or temperature is more conservative with respect to the limits specified by the IEC. A simulation model was constructed including coil housing and MR environment. Lumped elements and feed networks were modeled by a network co-simulation. The model was validated by comparison of S-parameters and B 1 + maps obtained in an anatomical phantom. Three numerical body models were generated based on 3 Tesla MRI images to conform to the coil housing. SAR calculations were performed and the maximal permissible input power was calculated based on IEC guidelines. Temperature simulations were performed based on the Pennes bioheat equation with the power absorption from the RF simulations as heat source. The blood perfusion was modeled as constant to reflect impaired patients as well as with a linear and exponential temperature-dependent increase to reflect two possible models for healthy subjects. Two ambient temperatures were considered to account for cooling effects from the environment. The simulation model was validated with a mean deviation of 3% between measurement and simulation results. The highest 10 g-averaged SAR was found in lung and muscle tissue on the right side of the upper torso. The maximum permissible input power was calculated to be 17 W. The

  11. CELLULAR CONTROL OF CONNECTIVE TISSUE MATRIX TENSION†

    OpenAIRE

    Langevin, Helene M.; Nedergaard, Maiken; Howe, Alan

    2013-01-01

    The biomechanical behavior of connective tissue in response to stretching is generally attributed to the molecular composition and organization of its extracellular matrix. It also is becoming apparent that fibroblasts play an active role in regulating connective tissue tension. In response to static stretching of the tissue, fibroblasts expand within minutes by actively remodeling their cytoskeleton. This dynamic change in fibroblast shape contributes to the drop in tissue tension that occur...

  12. Variation in alternative splicing across human tissues

    OpenAIRE

    Yeo, Gene; Holste, Dirk; Kreiman, Gabriel; Burge, Christopher B

    2004-01-01

    Background: Alternative pre-mRNA splicing (AS) is widely used by higher eukaryotes to generate different protein isoforms in specific cell or tissue types. To compare AS events across human tissues, we analyzed the splicing patterns of genomically aligned expressed sequence tags (ESTs) derived from libraries of cDNAs from different tissues. Results: Controlling for differences in EST coverage among tissues, we found that the brain and testis had the highest levels of exon skipping. The most p...

  13. Scientific and industrial status of tissue engineering ...

    African Journals Online (AJOL)

    Tissue engineering is a newly emerging field targeting many unresolved health problems. So far, the achievements of this technology in the production of different tissue engineered substitutes were promising. This review is intended to describe, briefly and in a simple language, what tissue engineering is, what the ...

  14. Mechanics of needle-tissue interaction

    NARCIS (Netherlands)

    Roesthuis, Roy; van Veen, Youri; Jahya, Alex; Misra, Sarthak

    2011-01-01

    When a needle is inserted into soft tissue, interac- tion forces are developed at the needle tip and along the needle shaft. The needle tip force is due to cutting of the tissue, and the force along the needle shaft is due to friction between needle and tissue. In this study, the friction force is

  15. Engineering vascular development for tissue regeneration

    NARCIS (Netherlands)

    Rivron, N.C.

    2010-01-01

    Tissue engineering and regenerative medicine aim at restoring a damaged tissue by recreating in vitro or promoting its regeneratin in vovo. The vasculature is central to these therapies for the irrigation of the defective tissue (oxygen, nutrients or circulating regenerative cells) and as an

  16. Extracellular matrix and tissue engineering applications

    NARCIS (Netherlands)

    Fernandes, H.A.M.; Moroni, Lorenzo; van Blitterswijk, Clemens; de Boer, Jan

    2009-01-01

    The extracellular matrix is a key component during regeneration and maintenance of tissues and organs, and it therefore plays a critical role in successful tissue engineering as well. Tissue engineers should recognise that engineering technology can be deduced from natural repair processes. Due to

  17. Facial sculpting and tissue augmentation.

    Science.gov (United States)

    Carruthers, Jean D A; Carruthers, Alastair

    2005-11-01

    Until recently, deep facial sculpting was exclusively the domain of surgical interventions. Recent advances in the available array of dermal and subdermal fillers combined with an esthetic appreciation by both surgeons and nonsurgeons alike of the positive effect of filling the volume-depleted face have led to an expansion in the indications for the use of soft tissue augmenting agents. Subdermal support of the lateral two-thirds of the brow, the nasojugal fold, the malar and buccal fat pads, the lateral lip commissures, and the perioral region, including the pre-jowl sulcus, all restore youthful facial contour and harmony. An important advance in technique is the subdermal rather than the intradermal injection plane. "Instant" facial sculpting giving a brow-lift, cheek-lift, lip expansion, and perioral augmentation is possible using modern soft tissue augmenting agents. The softer, more relaxed appearance contrasts to the somewhat "pulled" appearance of subjects who have had surgical overcorrections. Treatments can be combined with botulinum toxin and other procedures if required. Newer advances in the use of fillers include the use of fillers injected in the subdermal plane for "lunchtime" facial sculpting. Using the modern esthetic filler compounds, which are biodegradable but longer lasting, subjects can have a "rehearsal" treatment or make it ongoing. Some individuals, such as those with human immunodeficiency virus (HIV)-related lipoatrophy or those who desire to obtain a longer-lasting effect, may elect to use a nonbiodegradable filling agent.

  18. [Update on soft tissue sarcomas].

    Science.gov (United States)

    Bui, Binh Nguyen; Tabrizi, Reza; Dagada, Corinne; Trufflandier, Nathalie; St ckle, Eberhard; Coindre, Jean-Michel

    2002-01-01

    Important refinements have taken place in the diagnosis of soft tissue sarcoma with extensive use of immuno-histochemistry. New entities have been described, while malignant histiocytofibroma, the most diagnosed sarcoma type during the last two decades, has been dismembered. As for prognosis, the new UICC classification is effectively more discriminating in the definition of prognostic groups; but the usefullness of new biological or genetic markers remains to be assessed. Several breakthrough have taken place in the last years in the treatment of soft tissue sarcoma. Isolated limb perfusion with TNF, hyperthermia and melphalan have proven its efficacy, and is now an alternative to preoperative chemotherapy and/or radiotherapy for limb sparing treatment of the primary tumor site or to amputation. For systemic treatments, novel cytostatic drugs have been shown to be active in sarcomas, including ecteinascidine (ET743) and Glivec (STI571). This last drug has been shown to be remarkably active in c-kit+ stromal sarcoma of the gastro-intestinal tract. It can hopefully regarded as an example for targeted therapies, which may come with a better understanding of the molecular mechanisms triggered by the fundamental, specific genetic alterations shown in sarcoma.

  19. Nanotechnology in bone tissue engineering.

    Science.gov (United States)

    Walmsley, Graham G; McArdle, Adrian; Tevlin, Ruth; Momeni, Arash; Atashroo, David; Hu, Michael S; Feroze, Abdullah H; Wong, Victor W; Lorenz, Peter H; Longaker, Michael T; Wan, Derrick C

    2015-07-01

    Nanotechnology represents a major frontier with potential to significantly advance the field of bone tissue engineering. Current limitations in regenerative strategies include impaired cellular proliferation and differentiation, insufficient mechanical strength of scaffolds, and inadequate production of extrinsic factors necessary for efficient osteogenesis. Here we review several major areas of research in nanotechnology with potential implications in bone regeneration: 1) nanoparticle-based methods for delivery of bioactive molecules, growth factors, and genetic material, 2) nanoparticle-mediated cell labeling and targeting, and 3) nano-based scaffold construction and modification to enhance physicochemical interactions, biocompatibility, mechanical stability, and cellular attachment/survival. As these technologies continue to evolve, ultimate translation to the clinical environment may allow for improved therapeutic outcomes in patients with large bone deficits and osteodegenerative diseases. Traditionally, the reconstruction of bony defects has relied on the use of bone grafts. With advances in nanotechnology, there has been significant development of synthetic biomaterials. In this article, the authors provided a comprehensive review on current research in nanoparticle-based therapies for bone tissue engineering, which should be useful reading for clinicians as well as researchers in this field. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Flocking Transition in Confluent Tissues

    Science.gov (United States)

    Paoluzzi, Matteo; Giavazzi, Fabio; Macchi, Marta; Scita, Giorgio; Cerbino, Roberto; Manning, Lisa; Marchetti, Cristina

    The emerging of collective migration in biological tissues plays a pivotal role in embryonic morphogenesis, wound healing and cancer invasion. While many aspects of single cell movements are well established, the mechanisms leading to coherent displacements of cohesive cell groups are still poorly understood. Some of us recently proposed a Self-Propelled Voronoi (SPV) model of dense tissues that combines self-propelled particle models and vertex models of confluent cell layers and exhibits a liquid-solid transition as a function of cell shape and cell motility. We now examine the role of cell polarization on collective cell dynamics by introducing an orientation mechanism that aligns cell polarization with local cell motility. The model predicts a density-independent flocking transition tuned by the strength of the aligning interaction, with both solid and liquid flocking states existing in different regions of parameter space. MP and MCM were supported by the Simons Foundation Targeted Grant in the Mathematical Modeling of Living Systems Number: 342354 and by the Syracuse Soft Matter Program.

  1. Human tissue in systems medicine.

    Science.gov (United States)

    Caie, Peter D; Schuur, Klaas; Oniscu, Anca; Mullen, Peter; Reynolds, Paul A; Harrison, David J

    2013-12-01

    Histopathology, the examination of an architecturally artefactual, two-dimensional and static image remains a potent tool allowing diagnosis and empirical expectation of prognosis. Considerable optimism exists that the advent of molecular genetic testing and other biomarker strategies will improve or even replace this ancient technology. A number of biomarkers already add considerable value for prediction of whether a treatment will work. In this short review we argue that a systems medicine approach to pathology will not seek to replace traditional pathology, but rather augment it. Systems approaches need to incorporate quantitative morphological, protein, mRNA and DNA data. A significant challenge for clinical implementation of systems pathology is how to optimize information available from tissue, which is frequently sub-optimal in quality and amount, and yet generate useful predictive models that work. The transition of histopathology to systems pathophysiology and the use of multiscale data sets usher in a new era in diagnosis, prognosis and prediction based on the analysis of human tissue. © 2013 The Authors. FEBS Journal published by John Wiley & Sons Ltd on behalf of FEBS.

  2. Brown adipose tissue in cetacean blubber.

    Directory of Open Access Journals (Sweden)

    Osamu Hashimoto

    Full Text Available Brown adipose tissue (BAT plays an important role in thermoregulation in species living in cold environments, given heat can be generated from its chemical energy reserves. Here we investigate the existence of BAT in blubber in four species of delphinoid cetacean, the Pacific white-sided and bottlenose dolphins, Lagenorhynchus obliquidens and Tursiops truncates, and Dall's and harbour porpoises, Phocoenoides dalli and Phocoena phocoena. Histology revealed adipocytes with small unilocular fat droplets and a large eosinophilic cytoplasm intermingled with connective tissue in the innermost layers of blubber. Chemistry revealed a brown adipocyte-specific mitochondrial protein, uncoupling protein 1 (UCP1, within these same adipocytes, but not those distributed elsewhere throughout the blubber. Western blot analysis of extracts from the inner blubber layer confirmed that the immunohistochemical positive reaction was specific to UCP1 and that this adipose tissue was BAT. To better understand the distribution of BAT throughout the entire cetacean body, cadavers were subjected to computed tomography (CT scanning. Resulting imagery, coupled with histological corroboration of fine tissue structure, revealed adipocytes intermingled with connective tissue in the lowest layer of blubber were distributed within a thin, highly dense layer that extended the length of the body, with the exception of the rostrum, fin and fluke regions. As such, we describe BAT effectively enveloping the cetacean body. Our results suggest that delphinoid blubber could serve a role additional to those frequently attributed to it: simple insulation blanket, energy storage, hydrodynamic streamlining or contributor to positive buoyancy. We believe delphinoid BAT might also function like an electric blanket, enabling animals to frequent waters cooler than blubber as an insulator alone might otherwise allow an animal to withstand, or allow animals to maintain body temperature in cool

  3. Effects of temperature and salinity on survival rate of cultured corals and photosynthetic efficiency of zooxanthellae in coral tissues

    Science.gov (United States)

    Kuanui, Pataporn; Chavanich, Suchana; Viyakarn, Voranop; Omori, Makoto; Lin, Chiahsin

    2015-06-01

    This study investigated the effects of temperature and salinity on growth, survival, and photosynthetic efficiency of three coral species, namely, Pocillopora damicornis, Acropora millepora and Platygyra sinensis of different ages (6 and 18 months old). The experimental corals were cultivated via sexual propagation. Colonies were exposed to 5 different temperatures (18, 23, 28, 33, and 38°C) and 5 different salinities (22, 27, 32, 37, and 42 psu). Results showed that temperature significantly affected photosynthetic efficiency (Fv/Fm) (p < 0.05) compared to salinity. The maximum quantum yield of corals decreased ranging from 5% to 100% when these corals were exposed to different temperatures and salinities. Temperature also significantly affected coral growth and survival. However, corals exposed to changes in salinity showed higher survivorship than those exposed to changes in temperature. Results in this study also showed that corals of different ages and of different species did not display the same physiological responses to changes in environmental conditions. Thus, the ability of corals to tolerate salinity and temperature stresses depends on several factors.

  4. Ergot alkaloid transport across ruminant gastric tissues.

    Science.gov (United States)

    Hill, N S; Thompson, F N; Stuedemann, J A; Rottinghaus, G W; Ju, H J; Dawe, D L; Hiatt, E E

    2001-02-01

    Ergot alkaloids cause fescue toxicosis when livestock graze endophyte-infected tall fescue. It is generally accepted that ergovaline is the toxic component of endophyte-infected tall fescue, but there is no direct evidence to support this hypothesis. The objective of this study was to examine relative and potential transport of ergoline and ergopeptine alkaloids across isolated gastric tissues in vitro. Sheep ruminal and omasal tissues were surgically removed and placed in parabiotic chambers. Equimolar concentrations of lysergic acid, lysergol, ergonovine, ergotamine, and ergocryptine were added to a Kreb's Ringer phosphate (KRP) solution on the mucosal side of the tissue. Tissue was incubated in near-physiological conditions for 240 min. Samples were taken from KRP on the serosal side of the chambers at times 0, 30, 60, 120, 180, and 240 min and analyzed for ergot alkaloids by competitive ELISA. The serosal KRP remaining after incubation was freeze-dried and the alkaloid species quantified by HPLC. The area of ruminal and omasal tissues was measured and the potential transportable alkaloids calculated by multiplying the moles of transported alkaloids per square centimeter of each tissue type by the surface area of the tissue. Studies were conducted to compare alkaloid transport in reticular, ruminal, and omasal tissues and to determine whether transport was active or passive. Ruminal tissue had greater ergot alkaloid transport potential than omasal tissue (85 vs 60 mmol) because of a larger surface area. The ruminal posterior dorsal sac had the greatest potential for alkaloid transport, but the other ruminal tissues were not different from one another. Alkaloid transport was less among reticular tissues than among ruminal tissues. Transport of alkaloids seemed to be an active process. The alkaloids with greatest transport potential were lysergic acid and lysergol. Ergopeptine alkaloids tended to pass across omasal tissues in greater quantities than across ruminal

  5. Piezoelectric materials for tissue regeneration: A review.

    Science.gov (United States)

    Rajabi, Amir Hossein; Jaffe, Michael; Arinzeh, Treena Livingston

    2015-09-01

    The discovery of piezoelectricity, endogenous electric fields and transmembrane potentials in biological tissues raised the question whether or not electric fields play an important role in cell function. It has kindled research and the development of technologies in emulating biological electricity for tissue regeneration. Promising effects of electrical stimulation on cell growth and differentiation and tissue growth has led to interest in using piezoelectric scaffolds for tissue repair. Piezoelectric materials can generate electrical activity when deformed. Hence, an external source to apply electrical stimulation or implantation of electrodes is not needed. Various piezoelectric materials have been employed for different tissue repair applications, particularly in bone repair, where charges induced by mechanical stress can enhance bone formation; and in neural tissue engineering, in which electric pulses can stimulate neurite directional outgrowth to fill gaps in nervous tissue injuries. In this review, a summary of piezoelectricity in different biological tissues, mechanisms through which electrical stimulation may affect cellular response, and recent advances in the fabrication and application of piezoelectric scaffolds will be discussed. The discovery of piezoelectricity, endogenous electric fields and transmembrane potentials in biological tissues has kindled research and the development of technologies using electrical stimulation for tissue regeneration. Piezoelectric materials generate electrical activity in response to deformations and allow for the delivery of an electrical stimulus without the need for an external power source. As a scaffold for tissue engineering, growing interest exists due to its potential of providing electrical stimulation to cells to promote tissue formation. In this review, we cover the discovery of piezoelectricity in biological tissues, its connection to streaming potentials, biological response to electrical stimulation and

  6. Morphogenesis and tissue culture of sweet orange (Citrus sinensis (L.) Osb.): effect of temperature and photosynthetic radiation

    International Nuclear Information System (INIS)

    Duran-Vila, N.; Gogorcena, Y.; Ortega, V.; Ortiz, J.; Navarro, L.

    1992-01-01

    Both incubation temperature and photosynthetic radiation affected morphogenesis, callus culture and plantlet culture of sweet orange (Citrus sinensis) cultured in vitro. Bud culture from nodal stem segments, regeneration of shoots and buds from internode stem segments and induction of primary callus were near optimal at incubation temperatures between 21–30°C. The optimal temperature for root formation was 27°C with temperatures above and below being clearly deleterious. Incubation in the dark or under low photosynthetic photon flux density (PPFD) was beneficial for callus induction and growth and also favored the production of rooted plantlets from bud cultures. Incubation in the dark improved considerably the regeneration of shoots and buds from internode segments and the recovery of whole plants. No off-types, as determined by protein and isoenzyme analysis, were observed among plantlets recovered from bud cultures or from regeneration of shoots from internode stem segments

  7. Comparison of tissue deterioration of ripening banana fruit (Musa spp., AAA group, Cavendish subgroup) under chilling and non-chilling temperatures.

    Science.gov (United States)

    Ramírez-Sánchez, Maricruz; Huber, Donald J; Vallejos, Carlos E

    2018-03-08

    In fleshy fruits, induced programmed cell death (PCD) has been observed in heat-treated tomato, and in ethylene-treated and low-temperature exposure in immature cucumber. No other fleshy fruit has been evaluated for chilling-injury-induced PCD, especially mature fruit with full ripening capacity. The purpose of this research was to identify and evaluate the presence of PCD processes during the development of low-temperature-induced physiopathy of banana fruit. Exposure of fruit to 5 °C for 4 days induced degradative processes similar to those occurring during ripening and overripening of non-chilled fruit. Nuclease from banana peel showed activity in both DNA substrates and RNA substrates. No exclusive low-temperature-induced proteases and nucleases were observed. DNA of chilled peel showed earlier signs of degradation and higher levels of DNA tailing during overripening. This study shows that exposure to low temperatures did not induce a pattern of degradative processes that differed from that occurring during ripening and overripening of non-chilled fruit. DNA showed earlier signs of degradation and higher levels of DNA tailing. Nuclease activity analysis showed bifunctionality in both chilled and non-chilled tissue and no chilling-exclusive protease and nuclease. Fleshy fruit might use their available resources on degradative processes and adjust them depending on environmental conditions. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  8. Quantification of thermal damage in skin tissue

    Institute of Scientific and Technical Information of China (English)

    Xu Feng; Wen Ting; Lu Tianjian; Seffen Keith

    2008-01-01

    Skin thermal damage or skin burns are the most commonly encountered type of trauma in civilian and military communities. Besides, advances in laser, microwave and similar technologies have led to recent developments of thermal treatments for disease and damage involving skin tissue, where the objective is to induce thermal damage precisely within targeted tissue structures but without affecting the surrounding, healthy tissue. Further, extended pain sensation induced by thermal damage has also brought great problem for burn patients. Thus, it is of great importance to quantify the thermal damage in skin tissue. In this paper, the available models and experimental methods for quantification of thermal damage in skin tissue are discussed.

  9. Electroroentgenography in diagnosis of soft tissue tumors

    International Nuclear Information System (INIS)

    Vintergal'ter, S.F.; Vishevnik, B.I.

    1989-01-01

    Clinical, electroroentgenographic and X-ray studies of soft tissues were carried out in 425 patients with malignant (75), benign (246) soft tissue tumors and in cases of such soft tissue pathologies of the extremities and body (104). The paper discusses the technicalities of electroroentgenography which produces on one roentgenogram separate images of all components of soft tissues and bones in a given segment. A comparions of image quality assured by electroroentgeno- and roentgenography did not establish any significant difference in soft tissue tumor semiotics

  10. Diagnosis of breast cancer by tissue analysis

    Institute of Scientific and Technical Information of China (English)

    Debnath Bhattacharyya; Samir Kumar Bandyopadhyay; Tai-hoon Kim

    2013-01-01

    In this paper,we propose a technique to locate abnormal growth of cells in breast tissue and suggest further pathological test,when require.We compare normal breast tissue with malignant invasive breast tissue by a series of image processing steps.Normal ductal epithelial cells and ductal/lobular invasive carcinogenic cells also consider for comparison here in this paper.In fact,features of cancerous breast tissue (invasive) are extracted and analyses with normal breast tissue.We also suggest the breast cancer recognition technique through image processing and prevention by controlling p53 gene mutation to some extent.

  11. Hardwiring Stem Cell Communication through Tissue Structure.

    Science.gov (United States)

    Xin, Tianchi; Greco, Valentina; Myung, Peggy

    2016-03-10

    Adult stem cells across diverse organs self-renew and differentiate to maintain tissue homeostasis. How stem cells receive input to preserve tissue structure and function largely relies on their communication with surrounding cellular and non-cellular elements. As such, how tissues are organized and patterned not only reflects organ function, but also inherently hardwires networks of communication between stem cells and their environment to direct tissue homeostasis and injury repair. This review highlights how different methods of stem cell communication reflect the unique organization and function of diverse tissues. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Hardwiring stem cell communication through tissue structure

    Science.gov (United States)

    Xin, Tianchi; Greco, Valentina; Myung, Peggy

    2016-01-01

    Adult stem cells across diverse organs self-renew and differentiate to maintain tissue homeostasis. How stem cells receive input to preserve tissue structure and function largely relies on their communication with surrounding cellular and non-cellular elements. As such, how tissues are organized and patterned not only reflects organ function but also inherently hardwires networks of communication between stem cells and their environment to direct tissue homeostasis and injury repair. This review highlights how different methods of stem cell communication reflect the unique organization and function of diverse tissues. PMID:26967287

  13. Microwave Tissue Ablation: Biophysics, Technology and Applications

    Science.gov (United States)

    2010-01-01

    Microwave ablation is an emerging treatment option for many cancers, cardiac arrhythmias and other medical conditions. During treatment, microwaves are applied directly to tissues to produce rapid temperature elevations sufficient to produce immediate coagulative necrosis. The engineering design criteria for each application differ, with individual consideration for factors such as desired ablation zone size, treatment duration, and procedural invasiveness. Recent technological developments in applicator cooling, power control and system optimization for specific applications promise to increase the utilization of microwave ablation in the future. This article will review the basic biophysics of microwave tissue heating, provide an overview of the design and operation of current equipment, and outline areas for future research for microwave ablation. PMID:21175404

  14. NONCHEMICAL DEHYDRATION OF FIXED TISSUE COMBINING MICROWAVES AND VACUUM

    NARCIS (Netherlands)

    KOK, LP; BOON, ME

    A novel histoprocessing method for paraffin and plastic sections is presented in which dehydration of fixed tissue blocks is achieved within 5 minutes by microwaving under vacuum. Exploiting the decrease in boiling temperature under vacuum, we succeed in evaporating liquid molecules in the tissues

  15. Temperature-responsive grafted polymer brushes obtained from renewable sources with potential application as substrates for tissue engineering

    Science.gov (United States)

    Raczkowska, Joanna; Stetsyshyn, Yurij; Awsiuk, Kamil; Lekka, Małgorzata; Marzec, Monika; Harhay, Khrystyna; Ohar, Halyna; Ostapiv, Dmytro; Sharan, Mykola; Yaremchuk, Iryna; Bodnar, Yulia; Budkowski, Andrzej

    2017-06-01

    The novel temperature-responsive poly(cholesteryl methacylate) (PChMa) coatings derived from renewable sources were synthesized and characterized. Temperature induced changes in wettability were accompanied by surface roughness modifications, traced with AFM. Topographies recorded for temperatures increasing from 5 to 25 °C showed a slight but noticeable increase of calculated root mean square (RMS) roughness by a factor of 1.5, suggesting a horizontal rearrangement in the structure of PChMa coatings. Another structural reordering was observed in the 55-85 °C temperature range. The recorded topography changed noticeably from smooth at 55 °C to very structured and rough at 60 °C and returned eventually to relatively smooth at 85 °C. In addition, temperature transitions of PChMa molecules were revealed by DSC measurements. The biocompatibility of the PChMa-grafted coatings was shown for cultures of granulosa cells and a non malignant bladder cancer cell (HCV29 line) culture.

  16. Quality system in Malaysian National Tissue Bank

    International Nuclear Information System (INIS)

    Go Boon Thong; Firdaus, M. N.; Abd Rani Shamsudin

    1999-01-01

    Quality System in Malaysian National Tissue Bank is based on the Quality Manual which has been drawn up by the chairman, who is the Dean, School of Medical Sciences. The Quality Manual include general standard for Tissue Banking in University Science of Malaysia which describe and explain a set of general standard similar to the EATB standard. The primary aim of the quality system is to produce a safe and effective tissue graft for successful clinical use and to ensure the safety of tissue bank operators. The Quality Manual also related the role of a Technical Manual, which explain the standard of technical aspect of tissue bank in a Quality Assurance. The safe working environment and Good Laboratory Practice is highlight in Quality System. Documentation of tissue bank activities is the key to the administration to tissue bank. Finally Quality System in tissue banking will never be complete without a Tissue Bank Auditing System which allow the tissue bank coordinator and staff to look into the problem and further enhance the progress of the tissue bank

  17. Calculation of neutron kerma in tissues

    International Nuclear Information System (INIS)

    Vega C, H.R.; Manzanares A, E.

    2004-01-01

    Neutron kerma of normal and tumor tissues has been calculated using the tissues elemental concentration. A program developed in Math cad contains the kerma factors of C, H, O, N, Na, Mg, P, S, Cl, K, etc. that are in normal and tumor human tissues. Having the elemental composition of any human tissue the neutron kerma can be calculated. The program was tested using the elemental composition of tumor tissues such as sarcoma, melanoma, carcinoma and adenoid cystic, also neutron kerma for adipose and muscle tissue for normal adult was calculated. The results are in agreement with those published in literature. The neutron kerma for water was also calculated because in some dosimetric calculations water is used to describe normal and tumor tissues. From this comparison was found that at larger energies kerma factors are approximately the same, but energies less than 100 eV the differences are large. (Author)

  18. Microbial Biofilms and Breast Tissue Expanders

    Directory of Open Access Journals (Sweden)

    Melissa J. Karau

    2013-01-01

    Full Text Available We previously developed and validated a vortexing-sonication technique for detection of biofilm bacteria on the surface of explanted prosthetic joints. Herein, we evaluated this technique for diagnosis of infected breast tissue expanders and used it to assess colonization of breast tissue expanders. From April 2008 to December 2011, we studied 328 breast tissue expanders at Mayo Clinic, Rochester, MN, USA. Of seven clinically infected breast tissue expanders, six (85.7% had positive cultures, one of which grew Propionibacterium species. Fifty-two of 321 breast tissue expanders (16.2%, 95% CI, 12.3–20.7% without clinical evidence of infection also had positive cultures, 45 growing Propionibacterium species and ten coagulase-negative staphylococci. While vortexing-sonication can detect clinically infected breast tissue expanders, 16 percent of breast tissue expanders appear to be asymptomatically colonized with normal skin flora, most commonly, Propionibacterium species.

  19. Radiotherapy in patients with connective tissue diseases.

    Science.gov (United States)

    Giaj-Levra, Niccolò; Sciascia, Savino; Fiorentino, Alba; Fersino, Sergio; Mazzola, Rosario; Ricchetti, Francesco; Roccatello, Dario; Alongi, Filippo

    2016-03-01

    The decision to offer radiotherapy in patients with connective tissue diseases continues to be challenging. Radiotherapy might trigger the onset of connective tissue diseases by increasing the expression of self-antigens, diminishing regulatory T-cell activity, and activating effectors of innate immunity (dendritic cells) through Toll-like receptor-dependent mechanisms, all of which could potentially lead to breaks of immune tolerance. This potential risk has raised some debate among radiation oncologists about whether patients with connective tissue diseases can tolerate radiation as well as people without connective tissue diseases. Because the number of patients with cancer and connective tissue diseases needing radiotherapy will probably increase due to improvements in medical treatment and longer life expectancy, the issue of interactions between radiotherapy and connective tissue diseases needs to be clearer. In this Review, we discuss available data and evidence for patients with connective tissue diseases treated with radiotherapy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Variation in tissue outcome of ovine and human engineered heart valve constructs : relevance for tissue engineering

    NARCIS (Netherlands)

    Geemen, van D.; Driessen - Mol, A.; Grootzwagers, L.G.M.; Soekhradj - Soechit, R.S.; Riem Vis, P.W.; Baaijens, F.P.T.; Bouten, C.V.C.

    AIM: Clinical application of tissue engineered heart valves requires precise control of the tissue culture process to predict tissue composition and mechanical properties prior to implantation, and to understand the variation in tissue outcome. To this end we investigated cellular phenotype and

  1. Stem Cells and Tissue Engineering

    CERN Document Server

    Pavlovic, Mirjana

    2013-01-01

    Stem cells are the building blocks for all other cells in an organism. The human body has about 200 different types of cells and any of those cells can be produced by a stem cell. This fact emphasizes the significance of stem cells in transplantational medicine, regenerative therapy and bioengineering. Whether embryonic or adult, these cells can be used for the successful treatment of a wide range of diseases that were not treatable before, such as osteogenesis imperfecta in children, different forms of leukemias, acute myocardial infarction, some neural damages and diseases, etc. Bioengineering, e.g. successful manipulation of these cells with multipotential capacity of differentiation toward appropriate patterns and precise quantity, are the prerequisites for successful outcome and treatment. By combining in vivo and in vitro techniques, it is now possible to manage the wide spectrum of tissue damages and organ diseases. Although the stem-cell therapy is not a response to all the questions, it provides more...

  2. Ultraviolet injury of connective tissue

    International Nuclear Information System (INIS)

    Sengupta, K.P.; Sanyal, Sabitri; Biswas, S.K.; Pal, N.C.

    1975-01-01

    Changes induced by UV irradiation of rat skin could be divided morphologically into prenecrotic, necrotic and regenerating phases. During prenecrotic and necrotic phases, decrease in water content, collagenous protein, citrate buffer soluble fraction, elastin and total lipid and its fractions, and increase in noncollagenous protein nitrogen and fucoglycoprotein were observed. Increase in serum and urinary hydroxyproline and hexosamine, and serum sialic acid and fucose revealed the complicated nature of intrinsic changes occurring systemically. The study revealed that the ground substance was more easily affected while collagen, elastin and fat appeared to be more resistant to injury. This could be due to superficial action of radiation of short duration (30 min) on the dermal connective tissue. (author)

  3. Soft tissue aneurysmal bone cyst

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.L.; Gielen, J.L.; Delrue, F.; De Schepper, A.M.A. [Department of Radiology, Universitair Ziekenhuis Antwerpen (University of Antwerp), Wilrijkstraat 10, 2650, Edegem (Belgium); Salgado, R. [Department of Pathology, Universitair Ziekenhuis Antwerpen (University of Antwerp), Wilrijkstraat 10, 2650, Edegem (Belgium)

    2004-08-01

    A soft tissue aneurysmal bone cyst located in the right gluteus medius of a 21-year-old man is reported. On conventional radiography, the lesion demonstrated a spherically trabeculated mass with a calcific rim. On CT scan, it showed a well-organized peripheral calcification resembling a myositis ossificans. On MRI, it presented as a multilocular, cystic lesion with fluid-fluid levels. The lesion had no solid components except for intralesional septa. Although findings on imaging and histology were identical to those described in classical aneurysmal bone cyst, diagnosis was delayed because of lack of knowledge of this entity and its resemblance to the more familiar post-traumatic heterotopic ossification (myositis ossificans). (orig.)

  4. Soft tissue aneurysmal bone cyst

    International Nuclear Information System (INIS)

    Wang, X.L.; Gielen, J.L.; Delrue, F.; De Schepper, A.M.A.; Salgado, R.

    2004-01-01

    A soft tissue aneurysmal bone cyst located in the right gluteus medius of a 21-year-old man is reported. On conventional radiography, the lesion demonstrated a spherically trabeculated mass with a calcific rim. On CT scan, it showed a well-organized peripheral calcification resembling a myositis ossificans. On MRI, it presented as a multilocular, cystic lesion with fluid-fluid levels. The lesion had no solid components except for intralesional septa. Although findings on imaging and histology were identical to those described in classical aneurysmal bone cyst, diagnosis was delayed because of lack of knowledge of this entity and its resemblance to the more familiar post-traumatic heterotopic ossification (myositis ossificans). (orig.)

  5. DYSTOCIA DUE TO SOFT TISSUE

    Science.gov (United States)

    DeCarle, Donald W.

    1954-01-01

    In dystocia caused by abnormal conditions of the soft parts, the etiologic changes may be either in the genital tissues or in adjacent soft structures. Broadly, the conditions causing the difficulty may be grouped as follows: (1) anomalies or congenital modifications; (2) tumors; (3) modifications due to age, accident or surgical operations; (4) modification of the expulsive forces; (5) abnormalities of the products of conception. Often in such circumstances cesarean section is necessary. Sometimes when tumor is present it can be removed before it interferes with delivery, but decision to excise the growth must be guided by such factors as the location of the lesion and the stage of gestation. This would determine to what extent the maintenance of pregnancy would be jeopardized by surgical intervention before term. PMID:13190430

  6. Confocal imaging of butterfly tissue.

    Science.gov (United States)

    Brunetti, Craig R

    2014-01-01

    To understand the molecular events responsible for morphological change requires the ability to examine gene expression in a wide range of organisms in addition to model systems to determine how the differences in gene expression correlate with phenotypic differences. There are approximately 12,000 species of butterflies, most, with distinct patterns on their wings. The most important tool for studying gene expression in butterflies is confocal imaging of butterfly tissue by indirect immunofluorescence using either cross-reactive antibodies from closely related species such as Drosophila or developing butterfly-specific antibodies. In this report, we describe how indirect immunofluorescence protocols can be used to visualize protein expression patterns on the butterfly wing imaginal disc and butterfly embryo.

  7. Tissue Biopsies in Diabetes Research

    DEFF Research Database (Denmark)

    Højlund, Kurt; Gaster, Michael; Beck-Nielsen, Henning

    2007-01-01

    resistance of glucose disposal and glycogen synthesis in this tissue are hallmark features of type 2 diabetes in humans (2,3). During the past two decades, we have carried out more than 1200 needle biopsies of skeletal muscle to study the cellular mechanisms underlying insulin resistance in type 2 diabetes....... Together with morphological studies, measurement of energy stores and metabolites, enzyme activity and phosphorylation, gene and protein expression in skeletal muscle biopsies have revealed a variety of cellular abnormalities in patients with type 2 diabetes and prediabetes. The possibility to establish...... and gene expression profiling on skeletal muscle biopsies have pointed to abnormalities in mitochondrial oxidative phosphorylation in type 2 diabetes. These novel insights will inevitably cause a renewed interest in studying skeletal muscle. This chapter reviews our experience to date and gives a thorough...

  8. Industrial tissue: perennialization of suppliers

    International Nuclear Information System (INIS)

    Pin, M.; Hutin, J.P.; Tetreau, F.

    1996-01-01

    The durability of industrial tissue is a necessary condition, and certainly the most important, for the performance of actual park and the successful of its renewal. Reciprocally, the maintenance and the evolution of the actual park, the preparation of its renewal, are sources of activities to insure this durability of industrial and favour their international development. In the period of reduced activity, which began for the nuclear market, the dialogue which has always existed between EDF and its suppliers must be reinforced, in the respect of their respective responsibility, to insure: a right reciprocal understanding of activities and strategies, a right adaptation to these activities, and finally, the maintenance of the competitiveness. (N.C.)

  9. Ultrasonic Histotripsy for Tissue Therapy

    Science.gov (United States)

    Pahk, K. J.; Dhar, D. K.; Malago, M.; Saffari, N.

    2015-01-01

    Hepatocyte transplantation has been considered and investigated as a promising and alternative method to liver transplantation for treating liver-based metabolic disorder in newborns over the past two decades. Although some clinical trials have been conducted and shown clinical benefits and outcomes, it is difficult to deliver and achieve a desired level of integration and transplantation of hepatocytes in the liver parenchyma. To overcome this problem, this work introduces an alternative method to a portal-infused-hepatocyte cell transplantation. To improve the level of engraftment of transplantable hepatocytes, these are injected directly into cavities generated by ultrasonic histotripsy. Histotripsy is an extracorporeal noninvasive technique which has been recently developed using high intensity focused ultrasound (HIFU) for inducing tissue fractionation with no coagulative necrosis. The exact mechanisms for the tissue fractionation are not well understood yet; but the possible mechanisms are thought to be a combination of nonlinear wave propagation effect, explosive bubble growth and ultrasonic atomization. The main objectives of this work are to demonstrate the feasibility of this new cell therapy and evaluate and distinguish between the different types of cavitation activity for either a thermally or a mechanically induced lesion. In the present work, numerical studies on the bubble dynamics (the Gilmore-Akulichev bubble model coupled with the Khokhlov-Zabolotskaya-Kuznetsov equation) and both ex- and in vivo liver experiments are conducted with histological analysis (haematoxylin and eosin stain). The numerical and the experimental results suggest that (a) the acoustic emissions emitted during the thermal ablation and the histotripsy exposure can be distinguished both numerically and experimentally and (b) the proposed cell therapy may potentially form an effective and safe clinical treatment for replacing and correcting disordered hepatocytes, although the

  10. Ultrasonic Histotripsy for Tissue Therapy

    International Nuclear Information System (INIS)

    Pahk, K J; Saffari, N; Dhar, D K; Malago, M

    2015-01-01

    Hepatocyte transplantation has been considered and investigated as a promising and alternative method to liver transplantation for treating liver-based metabolic disorder in newborns over the past two decades. Although some clinical trials have been conducted and shown clinical benefits and outcomes, it is difficult to deliver and achieve a desired level of integration and transplantation of hepatocytes in the liver parenchyma. To overcome this problem, this work introduces an alternative method to a portal-infused-hepatocyte cell transplantation. To improve the level of engraftment of transplantable hepatocytes, these are injected directly into cavities generated by ultrasonic histotripsy. Histotripsy is an extracorporeal noninvasive technique which has been recently developed using high intensity focused ultrasound (HIFU) for inducing tissue fractionation with no coagulative necrosis. The exact mechanisms for the tissue fractionation are not well understood yet; but the possible mechanisms are thought to be a combination of nonlinear wave propagation effect, explosive bubble growth and ultrasonic atomization. The main objectives of this work are to demonstrate the feasibility of this new cell therapy and evaluate and distinguish between the different types of cavitation activity for either a thermally or a mechanically induced lesion. In the present work, numerical studies on the bubble dynamics (the Gilmore-Akulichev bubble model coupled with the Khokhlov-Zabolotskaya-Kuznetsov equation) and both ex- and in vivo liver experiments are conducted with histological analysis (haematoxylin and eosin stain). The numerical and the experimental results suggest that (a) the acoustic emissions emitted during the thermal ablation and the histotripsy exposure can be distinguished both numerically and experimentally and (b) the proposed cell therapy may potentially form an effective and safe clinical treatment for replacing and correcting disordered hepatocytes, although the

  11. Analysis of biological tissues by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Bonkova, I.; Bujdos, M.; Miglierini, M.

    2016-01-01

    The aim of this work was to analyze of biological tissues by Moessbauer spectroscopy in terms of demonstration of the magnetic properties of iron and its structural positions. Lyophilized samples of the human brain, human and equine spleen were used for the analysis. The samples were measured with 57 Fe Moessbauer spectroscopy in transmission arrangement at room temperature (∼ 300 K) and at a temperature of liquid helium (4.2 K). The resulting Moessbauer spectra measured at room temperature had doublet character, which confirms the presence of non-magnetic particles. On the contrary, low-temperature measurements are a superposition of several sextet and one duplicate. Hyperfine parameters obtained are similar to those reported hematite, ferrihydrite or magnetite. (authors)

  12. Transcriptome architecture across tissues in the pig

    Directory of Open Access Journals (Sweden)

    Folch Josep M

    2008-04-01

    Full Text Available Abstract Background Artificial selection has resulted in animal breeds with extreme phenotypes. As an organism is made up of many different tissues and organs, each with its own genetic programme, it is pertinent to ask: How relevant is tissue in terms of total transcriptome variability? Which are the genes most distinctly expressed between tissues? Does breed or sex equally affect the transcriptome across tissues? Results In order to gain insight on these issues, we conducted microarray expression profiling of 16 different tissues from four animals of two extreme pig breeds, Large White and Iberian, two males and two females. Mixed model analysis and neighbor – joining trees showed that tissues with similar developmental origin clustered closer than those with different embryonic origins. Often a sound biological interpretation was possible for overrepresented gene ontology categories within differentially expressed genes between groups of tissues. For instance, an excess of nervous system or muscle development genes were found among tissues of ectoderm or mesoderm origins, respectively. Tissue accounted for ~11 times more variability than sex or breed. Nevertheless, we were able to confidently identify genes with differential expression across tissues between breeds (33 genes and between sexes (19 genes. The genes primarily affected by sex were overall different than those affected by breed or tissue. Interaction with tissue can be important for differentially expressed genes between breeds but not so much for genes whose expression differ between sexes. Conclusion Embryonic development leaves an enduring footprint on the transcriptome. The interaction in gene × tissue for differentially expressed genes between breeds suggests that animal breeding has targeted differentially each tissue's transcriptome.

  13. Impact of Temperature and Nutrients on Carbon: Nutrient Tissue Stoichiometry of Submerged Aquatic Plants: An Experiment and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Mandy Velthuis

    2017-05-01

    Full Text Available Human activity is currently changing our environment rapidly, with predicted temperature increases of 1–5°C over the coming century and increased nitrogen and phosphorus inputs in aquatic ecosystems. In the shallow parts of these ecosystems, submerged aquatic plants enhance water clarity by resource competition with phytoplankton, provide habitat, and serve as a food source for other organisms. The carbon:nutrient stoichiometry of submerged aquatic plants can be affected by changes in both temperature and nutrient availability. We hypothesized that elevated temperature leads to higher carbon:nutrient ratios through enhanced nutrient-use efficiency, while nutrient addition leads to lower carbon:nutrient ratios by the luxurious uptake of nutrients. We addressed these hypotheses with an experimental and a meta-analytical approach. We performed a full-factorial microcosm experiment with the freshwater plant Elodea nuttallii grown at 10, 15, 20, and 25°C on sediment consisting of pond soil/sand mixtures with 100, 50, 25, and 12.5% pond soil. To address the effect of climatic warming and nutrient addition on the carbon:nutrient stoichiometry of submerged freshwater and marine plants we performed a meta-analysis on experimental studies that elevated temperature and/or added nutrients (nitrogen and phosphorus. In the microcosm experiment, C:N ratios of Elodea nuttallii decreased with increasing temperature, and this effect was most pronounced at intermediate nutrient availability. Furthermore, higher nutrient availability led to decreased aboveground C:P ratios. In the meta-analysis, nutrient addition led to a 25, 22, and 16% reduction in aboveground C:N and C:P ratios and belowground C:N ratios, accompanied with increased N content. No consistent effect of elevated temperature on plant stoichiometry could be observed, as very few studies were found on this topic and contrasting results were reported. We conclude that while nutrient addition

  14. Regional deep hyperthermia: impact of observer variability in CT-based manual tissue segmentation on simulated temperature distribution

    Science.gov (United States)

    Aklan, Bassim; Hartmann, Josefin; Zink, Diana; Siavooshhaghighi, Hadi; Merten, Ricarda; Putz, Florian; Ott, Oliver; Fietkau, Rainer; Bert, Christoph

    2017-06-01

    The aim of this study was to systematically investigate the influence of the inter- and intra-observer segmentation variation of tumors and organs at risk on the simulated temperature coverage of the target. CT scans of six patients with tumors in the pelvic region acquired for radiotherapy treatment planning were used for hyperthermia treatment planning. To study the effect of inter-observer variation, three observers manually segmented in the CT images of each patient the following structures: fat, muscle, bone and the bladder. The gross tumor volumes (GTV) were contoured by three radiation oncology residents and used as the hyperthermia target volumes. For intra-observer variation, one of the observers of each group contoured the structures of each patient three times with a time span of one week between the segmentations. Moreover, the impact of segmentation variations in organs at risk (OARs) between the three inter-observers was investigated on simulated temperature distributions using only one GTV. The spatial overlap between individual segmentations was assessed by the Dice similarity coefficient (DSC) and the mean surface distance (MSD). Additionally, the temperatures T90/T10 delivered to 90%/10% of the GTV, respectively, were assessed for each observer combination. The results of the segmentation similarity evaluation showed that the DSC of the inter-observer variation of fat, muscle, the bladder, bone and the target was 0.68  ±  0.12, 0.88  ±  0.05, 0.73  ±  0.14, 0.91  ±  0.04 and 0.64  ±  0.11, respectively. Similar results were found for the intra-observer variation. The MSD results were similar to the DSCs for both observer variations. A statistically significant difference (p  <  0.05) was found for T90 and T10 in the predicted target temperature due to the observer variability. The conclusion is that intra- and inter-observer variations have a significant impact on the temperature coverage of the

  15. Conjunctival Tear Layer Temperature, Evaporation, Hyperosmolarity, Inflammation, Hyperemia, Tissue Damage, and Symptoms: A Review of an Amplifying Cascade.

    Science.gov (United States)

    McMonnies, Charles W

    2017-12-01

    This review examines the evidence for and significance of pre-conjunctival tear temperature being higher than central pre-corneal temperature with associated more rapid evaporation of warmer pre-conjunctival tears in normal eyes but especially in hyperemic dry eye disease. PubMed searches using the terms "evaporative dry eye," "conjunctival tear evaporation," "tear evaporation," and "dry eye conjunctival hyperemia" indicated 157, 49, 309, and 96 potentially relevant papers, respectively. Selections from these lists were the basis for examining the significance of the evidence relevant to pre-conjunctival tear layer temperature and evaporation. There is evidence supporting an amplifying inflammatory and para-inflammatory hyperemia dry eye cascade, which increases pre-conjunctival tear temperature and the risk of accelerated pre-conjunctival tear evaporation with exacerbated osmolarity elevation and inflammation. Dry eye cascade amplification is consistent with increases in symptoms and inflammatory as well as para-inflammatory hyperemia toward the end of the waking day. Apart from age-related conjunctivochalasis, dry eye-related conjunctival epithelial cell pathology including reduced goblet cell numbers and associated mucin deficiency, squamous metaplasia, and increased separation of cell layers could help to destabilize tears and facilitate evaporation as part of an amplifying cascade. Greater difficulty in assessing conjunctival tear break up may contribute to an underestimation of a role for faster evaporation of pre-conjunctival tears in dry eye disease and help explain any non-correspondence between symptoms and corneal signs of dry eye disease. Success with anti-inflammatory therapies for dry eye disease may be at least partly due to reductions in conjunctival hyperemia and deamplification of evaporative cascades. Conjunctival inflammatory hyperemia in other diseases may contribute to accelerated pre-conjunctival tear evaporation and the risk of tear

  16. Seasonal variation in the effect of constant ambient temperature of 24 C in reducing FDG uptake by brown adipose tissue in children

    International Nuclear Information System (INIS)

    Zukotynski, Katherine A.; Fahey, Frederic H.; Laffin, Stephen; Davis, Royal; Treves, S. Ted; Grant, Frederick D.; Drubach, Laura A.

    2010-01-01

    It has been shown that warming patients prior to and during 18 F-FDG uptake by controlling the room temperature can decrease uptake by brown adipose tissue (BAT). The aim of this study is to determine if this effect is subject to seasonal variation. A retrospective review was conducted of all patients referred for whole-body 18 F-FDG PET between December 2006 and December 2008. After December 2007, all patients were kept in the PET injection room at a constant 24 C for 30 min before and until 1 h following FDG administration. Patients over 22 years of age and those who received pre-medication known to reduce FDG uptake by BAT were excluded. One hundred and three patients were warmed to 24 C prior to scanning. The number of patients showing uptake by BAT in this group was compared to a control group of 99 patients who underwent PET prior to December 2007 when the injection room temperature was 21 C. Uptake by BAT occurred in 9% of studies performed after patient warming (24 C), compared to 27% of studies performed on the control group (21 C) (p 0.05). Maintaining room temperature at a constant 24 C for 30 min prior to and 1 h after IV tracer administration significantly decreases FDG uptake by BAT in children. This effect is greatest in the summer and winter. (orig.)

  17. Transcriptomic analyses on muscle tissues of Litopenaeus vannamei provide the first profile insight into the response to low temperature stress.

    Directory of Open Access Journals (Sweden)

    Wen Huang

    Full Text Available The Pacific white shrimp (Litopenaeus vannamei is an important cultured crustacean species worldwide. However, little is known about the molecular mechanism of this species involved in the response to cold stress. In this study, four separate RNA-Seq libraries of L. vannamei were generated from 13°C stress and control temperature. Total 29,662 of Unigenes and overall of 19,619 annotated genes were obtained. Three comparisons were carried out among the four libraries, in which 72 of the top 20% of differentially-expressed genes were obtained, 15 GO and 5 KEGG temperature-sensitive pathways were fished out. Catalytic activity (GO: 0003824 and Metabolic pathways (ko01100 were the most annotated GO and KEGG pathways in response to cold stress, respectively. In addition, Calcium, MAPK cascade, Transcription factor and Serine/threonine-protein kinase signal pathway were picked out and clustered. Serine/threonine-protein kinase signal pathway might play more important roles in cold adaptation, while other three signal pathway were not widely transcribed. Our results had summarized the differentially-expressed genes and suggested the major important signaling pathways and related genes. These findings provide the first profile insight into the molecular basis of L. vannamei response to cold stress.

  18. Cell enlargement of plant tissue explants oscillates with a temperature-compensated period of ca. 24 min

    Science.gov (United States)

    Morre, D. James; Ternes, Philipp; Morre, Dorothy M.

    2002-01-01

    Rate of plant cell enlargement, measured at intervals of 3 min using a sensitive linear transducer, oscillates with a minimum period of about 24 min that parallels the 24-min periodicity observed with the oxidation of NADH by the external plasma membrane NADH oxidase and of single cells measured previously by video-enhanced light microscopy. Also exhibiting 24-min oscillations is the steady-state rate of cell enlargement induced by the addition of the auxin herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) or the natural auxin indole-3-acetic acid (IAA). Immediately following 2,4-D addition, a very complex pattern of oscillations is frequently observed. However, after several hours a dominant 24-min period emerges. The length of the 24-min period is temperature compensated and remains constant at 24 min when measured at 15, 25 or 35 degrees C, despite the fact that the rate of cell enlargement approximately doubles for each 10 degree C rise over this same range of temperatures.

  19. Survival of plant tissue at super-low temperatures v. An electron microscope study of ice in cortical cells cooled rapidly.

    Science.gov (United States)

    Sakai, A; Otsuka, K

    1967-12-01

    Experiments were carried out with cortical cells in twig bark of mulberry trees in winter in order to clarify the mechanism of survival at super-low temperatures with rapid cooling and rewarming. Attention was given to the relation between the existence of intracellular ice crystals and survival.Cortical cells were cooled rapidly by direct immersion into liquid nitrogen or isopentane cooled at various temperatures. After immersion, they were freeze-substituted with absolute ethanol at -78 degrees . They were then embedded, sectioned and examined under the electron microscope for the presence and distribution of cavities left after ice removal.Cells were found to remain alive and contain no ice cavities when immersed rapidly into isopentane baths kept below -60 degrees . Those cells at intermediate temperatures from -20 degrees to -45 degrees , were almost all destroyed. It was also observed that many ice cavities were contained in the cells immersed rapidly into isopentane baths at -30 degrees . The data seem to indicate that no ice crystals were formed when cooled rapidly by direct immersion into isopentane baths below -60 degrees or into liquid nitrogen.The tissue sections immersed in liquid nitrogen were rapidly transferred to isopentane baths at temperatures ranging from -70 degrees to -10 degrees before rapid rewarming. There was little damage when samples were held at temperatures below -50 degrees for 10 minutes or below -60 degrees for 16 hours. No cavities were found in these cells. Above -45 degrees , and especially at -30 degrees , however, all cells were completely destroyed even when exposed only for 1 minute. Many ice cavities were observed throughout these cells. The results obtained may be explained in terms of the growth rate of intracellular ice crystals.

  20. Optimal parameters for laser tissue soldering

    Science.gov (United States)

    McNally-Heintzelman, Karen M.; Sorg, Brian S.; Chan, Eric K.; Welch, Ashley J.; Dawes, Judith M.; Owen, Earl R.

    1998-07-01

    Variations in laser irradiance, exposure time, solder composition, chromophore type and concentration have led to inconsistencies in published results of laser-solder repair of tissue. To determine optimal parameters for laser tissue soldering, an in vitro study was performed using an 808-nm diode laser in conjunction with an indocyanine green (ICG)- doped albumin protein solder to weld bovine aorta specimens. Liquid and solid protein solders prepared from 25% and 60% bovine serum albumin (BSA), respectively, were compared. The effects of laser irradiance and exposure time on tensile strength of the weld and temperature rise as well as the effect of hydration on bond stability were investigated. Optimum irradiance and exposure times were identified for each solder type. Increasing the BSA concentration from 25% to 60% greatly increased the tensile strength of the weld. A reduction in dye concentration from 2.5 mg/ml to 0.25 mg/ml was also found to result in an increase in tensile strength. The strongest welds were produced with an irradiance of 6.4 W/cm2 for 50 s using a solid protein solder composed of 60% BSA and 0.25 mg/ml ICG. Steady-state solder surface temperatures were observed to reach 85 plus or minus 5 degrees Celsius with a temperature gradient across the solid protein solder strips of between 15 and 20 degrees Celsius. Finally, tensile strength was observed to decrease significantly (20 to 25%) after the first hour of hydration in phosphate-buffered saline. No appreciable change was observed in the strength of the tissue bonds with further hydration.

  1. Engineering complex orthopaedic tissues via strategic biomimicry.

    Science.gov (United States)

    Qu, Dovina; Mosher, Christopher Z; Boushell, Margaret K; Lu, Helen H

    2015-03-01

    The primary current challenge in regenerative engineering resides in the simultaneous formation of more than one type of tissue, as well as their functional assembly into complex tissues or organ systems. Tissue-tissue synchrony is especially important in the musculoskeletal system, wherein overall organ function is enabled by the seamless integration of bone with soft tissues such as ligament, tendon, or cartilage, as well as the integration of muscle with tendon. Therefore, in lieu of a traditional single-tissue system (e.g., bone, ligament), composite tissue scaffold designs for the regeneration of functional connective tissue units (e.g., bone-ligament-bone) are being actively investigated. Closely related is the effort to re-establish tissue-tissue interfaces, which is essential for joining these tissue building blocks and facilitating host integration. Much of the research at the forefront of the field has centered on bioinspired stratified or gradient scaffold designs which aim to recapitulate the structural and compositional inhomogeneity inherent across distinct tissue regions. As such, given the complexity of these musculoskeletal tissue units, the key question is how to identify the most relevant parameters for recapitulating the native structure-function relationships in the scaffold design. Therefore, the focus of this review, in addition to presenting the state-of-the-art in complex scaffold design, is to explore how strategic biomimicry can be applied in engineering tissue connectivity. The objective of strategic biomimicry is to avoid over-engineering by establishing what needs to be learned from nature and defining the essential matrix characteristics that must be reproduced in scaffold design. Application of this engineering strategy for the regeneration of the most common musculoskeletal tissue units (e.g., bone-ligament-bone, muscle-tendon-bone, cartilage-bone) will be discussed in this review. It is anticipated that these exciting efforts will

  2. Engineering Complex Orthopaedic Tissues via Strategic Biomimicry

    Science.gov (United States)

    Qu, Dovina; Mosher, Christopher Z.; Boushell, Margaret K.; Lu, Helen H.

    2014-01-01

    The primary current challenge in regenerative engineering resides in the simultaneous formation of more than one type of tissue, as well as their functional assembly into complex tissues or organ systems. Tissue-tissue synchrony is especially important in the musculoskeletal system, whereby overall organ function is enabled by the seamless integration of bone with soft tissues such as ligament, tendon, or cartilage, as well as the integration of muscle with tendon. Therefore, in lieu of a traditional single-tissue system (e.g. bone, ligament), composite tissue scaffold designs for the regeneration of functional connective tissue units (e.g. bone-ligament-bone) are being actively investigated. Closely related is the effort to re-establish tissue-tissue interfaces, which is essential for joining these tissue building blocks and facilitating host integration. Much of the research at the forefront of the field has centered on bioinspired stratified or gradient scaffold designs which aim to recapitulate the structural and compositional inhomogeneity inherent across distinct tissue regions. As such, given the complexity of these musculoskeletal tissue units, the key question is how to identify the most relevant parameters for recapitulating the native structure-function relationships in the scaffold design. Therefore, the focus of this review, in addition to presenting the state-of-the-art in complex scaffold design, is to explore how strategic biomimicry can be applied in engineering tissue connectivity. The objective of strategic biomimicry is to avoid over-engineering by establishing what needs to be learned from nature and defining the essential matrix characteristics that must be reproduced in scaffold design. Application of this engineering strategy for the regeneration of the most common musculoskeletal tissue units (e.g. bone-ligament-bone, muscle-tendon-bone, cartilage-bone) will be discussed in this review. It is anticipated that these exciting efforts will

  3. Bioprinting for vascular and vascularized tissue biofabrication.

    Science.gov (United States)

    Datta, Pallab; Ayan, Bugra; Ozbolat, Ibrahim T

    2017-03-15

    Bioprinting is a promising technology to fabricate design-specific tissue constructs due to its ability to create complex, heterocellular structures with anatomical precision. Bioprinting enables the deposition of various biologics including growth factors, cells, genes, neo-tissues and extra-cellular matrix-like hydrogels. Benefits of bioprinting have started to make a mark in the fields of tissue engineering, regenerative medicine and pharmaceutics. Specifically, in the field of tissue engineering, the creation of vascularized tissue constructs has remained a principal challenge till date. However, given the myriad advantages over other biofabrication methods, it becomes organic to expect that bioprinting can provide a viable solution for the vascularization problem, and facilitate the clinical translation of tissue engineered constructs. This article provides a comprehensive account of bioprinting of vascular and vascularized tissue constructs. The review is structured as introducing the scope of bioprinting in tissue engineering applications, key vascular anatomical features and then a thorough coverage of 3D bioprinting using extrusion-, droplet- and laser-based bioprinting for fabrication of vascular tissue constructs. The review then provides the reader with the use of bioprinting for obtaining thick vascularized tissues using sacrificial bioink materials. Current challenges are discussed, a comparative evaluation of different bioprinting modalities is presented and future prospects are provided to the reader. Biofabrication of living tissues and organs at the clinically-relevant volumes vitally depends on the integration of vascular network. Despite the great progress in traditional biofabrication approaches, building perfusable hierarchical vascular network is a major challenge. Bioprinting is an emerging technology to fabricate design-specific tissue constructs due to its ability to create complex, heterocellular structures with anatomical precision

  4. Tissue refractometry using Hilbert phase microscopy.

    Science.gov (United States)

    Lue, Niyom; Bewersdorf, Joerg; Lessard, Mark D; Badizadegan, Kamran; Dasari, Ramachandra R; Feld, Michael S; Popescu, Gabriel

    2007-12-15

    We present, for the first time to our knowledge, quantitative phase images associated with unstained 5 mum thick tissue slices of mouse brain, spleen, and liver. The refractive properties of the tissue are retrieved in terms of the average refractive index and its spatial variation. We find that the average refractive index varies significantly with tissue type, such that the brain is characterized by the lowest value and the liver by the highest. The spatial power spectra of the phase images reveal power law behavior with different exponents for each tissue type. This approach opens a new possibility for stain-free characterization of tissues, where the diagnostic power is provided by the intrinsic refractive properties of the biological structure. We present results obtained for liver tissue affected by a lysosomal storage disease and show that our technique can quantify structural changes during this disease development.

  5. CELLULAR CONTROL OF CONNECTIVE TISSUE MATRIX TENSION†

    Science.gov (United States)

    Langevin, Helene M.; Nedergaard, Maiken; Howe, Alan

    2013-01-01

    The biomechanical behavior of connective tissue in response to stretching is generally attributed to the molecular composition and organization of its extracellular matrix. It also is becoming apparent that fibroblasts play an active role in regulating connective tissue tension. In response to static stretching of the tissue, fibroblasts expand within minutes by actively remodeling their cytoskeleton. This dynamic change in fibroblast shape contributes to the drop in tissue tension that occurs during viscoelastic relaxation. We propose that this response of fibroblasts plays a role in regulating extracellular fluid flow into the tissue, and protects against swelling when the matrix is stretched. This article reviews the evidence supporting possible mechanisms underlying this response including autocrine purinergic signaling. We also discuss fibroblast regulation of connective tissue tension with respect to lymphatic flow, immune function and cancer. PMID:23444198

  6. Imaging of musculoskeletal soft tissue infections

    Energy Technology Data Exchange (ETDEWEB)

    Turecki, Marcin B.; Taljanovic, Mihra S.; Holden, Dean A.; Hunter, Tim B.; Rogers, Lee F. [University of Arizona HSC, Department of Radiology, Tucson, AZ (United States); Stubbs, Alana Y. [Southern Arizona VA Health Care System, Department of Radiology, Tucson, AZ (United States); Graham, Anna R. [University of Arizona HSC, Department of Pathology, Tucson, AZ (United States)

    2010-10-15

    Prompt and appropriate imaging work-up of the various musculoskeletal soft tissue infections aids early diagnosis and treatment and decreases the risk of complications resulting from misdiagnosis or delayed diagnosis. The signs and symptoms of musculoskeletal soft tissue infections can be nonspecific, making it clinically difficult to distinguish between disease processes and the extent of disease. Magnetic resonance imaging (MRI) is the imaging modality of choice in the evaluation of soft tissue infections. Computed tomography (CT), ultrasound, radiography and nuclear medicine studies are considered ancillary. This manuscript illustrates representative images of superficial and deep soft tissue infections such as infectious cellulitis, superficial and deep fasciitis, including the necrotizing fasciitis, pyomyositis/soft tissue abscess, septic bursitis and tenosynovitis on different imaging modalities, with emphasis on MRI. Typical histopathologic findings of soft tissue infections are also presented. The imaging approach described in the manuscript is based on relevant literature and authors' personal experience and everyday practice. (orig.)

  7. Imaging of musculoskeletal soft tissue infections

    International Nuclear Information System (INIS)

    Turecki, Marcin B.; Taljanovic, Mihra S.; Holden, Dean A.; Hunter, Tim B.; Rogers, Lee F.; Stubbs, Alana Y.; Graham, Anna R.

    2010-01-01

    Prompt and appropriate imaging work-up of the various musculoskeletal soft tissue infections aids early diagnosis and treatment and decreases the risk of complications resulting from misdiagnosis or delayed diagnosis. The signs and symptoms of musculoskeletal soft tissue infections can be nonspecific, making it clinically difficult to distinguish between disease processes and the extent of disease. Magnetic resonance imaging (MRI) is the imaging modality of choice in the evaluation of soft tissue infections. Computed tomography (CT), ultrasound, radiography and nuclear medicine studies are considered ancillary. This manuscript illustrates representative images of superficial and deep soft tissue infections such as infectious cellulitis, superficial and deep fasciitis, including the necrotizing fasciitis, pyomyositis/soft tissue abscess, septic bursitis and tenosynovitis on different imaging modalities, with emphasis on MRI. Typical histopathologic findings of soft tissue infections are also presented. The imaging approach described in the manuscript is based on relevant literature and authors' personal experience and everyday practice. (orig.)

  8. Using Polymeric Scaffolds for Vascular Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Alida Abruzzo

    2014-01-01

    Full Text Available With the high occurrence of cardiovascular disease and increasing numbers of patients requiring vascular access, there is a significant need for small-diameter (<6 mm inner diameter vascular graft that can provide long-term patency. Despite the technological improvements, restenosis and graft thrombosis continue to hamper the success of the implants. Vascular tissue engineering is a new field that has undergone enormous growth over the last decade and has proposed valid solutions for blood vessels repair. The goal of vascular tissue engineering is to produce neovessels and neoorgan tissue from autologous cells using a biodegradable polymer as a scaffold. The most important advantage of tissue-engineered implants is that these tissues can grow, remodel, rebuild, and respond to injury. This review describes the development of polymeric materials over the years and current tissue engineering strategies for the improvement of vascular conduits.

  9. Attenuation of the gamma rays in tissues

    International Nuclear Information System (INIS)

    Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Amador V, P.; Chacon R, A.; Vega C, H.R.

    2005-01-01

    The mass and lineal attenuation coefficient and of hepatic tissue, muscular, osseous and of brain before gamma rays of 10 -3 to 10 5 MeV were calculated. For the case of the osseous tissue the calculation was made for the cartilage, the cortical tissue and the bone marrow. During the calculations the elementary composition of the tissues of human origin was used. The calculations include by separate the Photoelectric effect, the Compton scattering and the Pair production, as well as the total. For to establish a comparison with the attenuation capacities, the coefficients of the water, the aluminum and the lead also were calculated. The study was complemented measuring the attenuation coefficient of hepatic tissue of bovine before gamma rays of 0.662 MeV of a source of 137 Cs. The measurement was made through of an experiment of photons transmission through samples frozen of hepatic tissue and with a Geiger-Mueller detector. (Author)

  10. Cellular control of connective tissue matrix tension.

    Science.gov (United States)

    Langevin, Helene M; Nedergaard, Maiken; Howe, Alan K

    2013-08-01

    The biomechanical behavior of connective tissue in response to stretching is generally attributed to the molecular composition and organization of its extracellular matrix. It also is becoming apparent that fibroblasts play an active role in regulating connective tissue tension. In response to static stretching of the tissue, fibroblasts expand within minutes by actively remodeling their cytoskeleton. This dynamic change in fibroblast shape contributes to the drop in tissue tension that occurs during viscoelastic relaxation. We propose that this response of fibroblasts plays a role in regulating extracellular fluid flow into the tissue, and protects against swelling when the matrix is stretched. This article reviews the evidence supporting possible mechanisms underlying this response including autocrine purinergic signaling. We also discuss fibroblast regulation of connective tissue tension with respect to lymphatic flow, immune function, and cancer. Copyright © 2013 Wiley Periodicals, Inc.

  11. Soft-tissue tension total knee arthroplasty.

    Science.gov (United States)

    Asano, Hiroshi; Hoshino, Akiho; Wilton, Tim J

    2004-08-01

    It is far from clear how best to define the proper strength of soft-tissue tensioning in total knee arthroplasty (TKA). We attached a torque driver to the Monogram balancer/tensor device and measured soft-tissue tension in full extension and 90 degrees flexion during TKA. In our surgical procedure, when we felt proper soft-tissue tension was being applied, the mean distraction force was noted to be 126N in extension and 121N in flexion. There was no significant correlation between soft-tissue tension and the postoperative flexion angle finally achieved. To the best of our knowledge, this is the first study to assess the actual distraction forces in relation to soft-tissue tension in TKA. Further study may reveal the most appropriate forces to achieve proper soft-tissue tension in the wide variety of circumstances presenting at knee arthroplasty.

  12. Dopaminergic Immunofluorescence Studies in Kidney Tissue.

    Science.gov (United States)

    Gildea, J J; Van Sciver, R E; McGrath, H E; Kemp, B A; Jose, P A; Carey, R M; Felder, R A

    2017-01-01

    The kidney is a highly integrated system of specialized differentiated cells that are responsible for fluid and electrolyte balance in the body. While much of today's research focuses on isolated nephron segments or cells from nephron segments grown in tissue culture, an often overlooked technique that can provide a unique view of many cell types in the kidney is slice culture. Here, we describe techniques that use freshly excised kidney tissue from rats to perform a variety of experiments shortly after isolating the tissue. By slicing the rat kidney in a "bread loaf" format, multiple studies can be performed on slices from the same tissue in parallel. Cryosectioning and staining of the tissue allow for the evaluation of physiological or biochemical responses in a wide variety of specific nephron segments. The procedures described within this chapter can also be extended to human or mouse kidney tissue.

  13. Quantification of thermal damage in skin tissue

    Institute of Scientific and Technical Information of China (English)

    徐峰; 文婷; 卢天健; Seffen; Keith

    2008-01-01

    Skin thermal damage or skin burns are the most commonly encountered type of trauma in civilian and military communities. Besides, advances in laser, microwave and similar technologies have led to recent developments of thermal treatments for disease and damage involving skin tissue, where the objective is to induce thermal damage precisely within targeted tissue structures but without affecting the surrounding, healthy tissue. Further, extended pain sensation induced by thermal damage has also brought great...

  14. Methadone Recycling Sustains Drug Reservoir in Tissue.

    Science.gov (United States)

    Linares, Oscar A; Fudin, Jeffrey; Daly, Annemarie; Schiesser, William E; Boston, Raymond C

    2015-09-01

    We hypothesize that there is a tissue store of methadone content in humans that is not directly accessible, but is quantifiable. Further, we hypothesize the mechanism by which methadone content is sustained in tissue stores involves methadone uptake, storage, and release from tissue depots in the body (recycling). Accordingly, we hypothesize that such tissue stores, in part, determine plasma methadone levels. We studied a random sample of six opioid-naïve healthy subjects. We performed a clinical trial simulation in silico using pharmacokinetic modeling. We found a large tissue store of methadone content whose size was much larger than methadone's size in plasma in response to a single oral dose of methadone 10 mg. The tissue store measured 13-17 mg. This finding could only be explained by the contemporaneous storage of methadone in tissue with dose recycling. We found that methadone recycles 2-5 times through an inaccessible extravascular compartment (IAC), from an accessible plasma-containing compartment (AC), before exiting irreversibly. We estimate the rate of accumulation (or storage) of methadone in tissue was 0.029-7.29 mg/h. We predict 39 ± 13% to 83 ± 6% of methadone's tissue stores "spillover" into the circulation. Our results indicate that there exists a large quantifiable tissue store of methadone in humans. Our results support the notion that methadone in humans undergoes tissue uptake, storage, release into the circulation, reuptake from the circulation, and re-release into the circulation, and that spillover of methadone from tissue stores, in part, maintain plasma methadone levels in humans.

  15. Phenylalanine kinetics in human adipose tissue.

    OpenAIRE

    Coppack, S W; Persson, M; Miles, J M

    1996-01-01

    Very little is known about the regulation of protein metabolism in adipose tissue. In this study systemic, adipose tissue, and forearm phenylalanine kinetics were determined in healthy postabsorptive volunteers before and during a 2-h glucose infusion (7 mg.kg-1.min-1). [3H]Phenylalanine was infused and blood was sampled from a radial artery, a subcutaneous abdominal vein, and a deep forearm vein. Adipose tissue and forearm blood flow were measured with 133Xe and plethysmography, respectively...

  16. Soft tissue grafting to improve implant esthetics

    Directory of Open Access Journals (Sweden)

    Moawia M Kassab

    2010-09-01

    Full Text Available Moawia M KassabDivision of Periodontics, Marquette University, School of Dentistry, Milwaukee, WI, USAAbstract: Dental implants are becoming the treatment of choice to replace missing teeth, especially if the adjacent teeth are free of restorations. When minimal bone width is present, implant placement becomes a challenge and often resulting in recession and dehiscence around the implant that leads to subsequent gingival recession. To correct such defect, the author turned to soft tissue autografting and allografting to correct a buccal dehiscence around tooth #24 after a malpositioned implant placed by a different surgeon. A 25-year-old woman presented with the chief complaint of gingival recession and exposure of implant threads around tooth #24. The patient received three soft tissue grafting procedures to augment the gingival tissue. The first surgery included a connective tissue graft to increase the width of the keratinized gingival tissue. The second surgery included the use of autografting (connective tissue graft to coronally position the soft tissue and achieve implant coverage. The third and final surgery included the use of allografting material Alloderm to increase and mask the implant from showing through the gingiva. Healing period was uneventful for the patient. After three surgical procedures, it appears that soft tissue grafting has increased the width and height of the gingiva surrounding the implant. The accomplished thickness of gingival tissue appeared to mask the showing of implant threads through the gingival tissue and allowed for achieving the desired esthetic that the patient desired. The aim of the study is to present a clinical case with soft tissue grafting procedures.Keywords: case report, connective tissue, dental implants, allograft, coronally positioned flap

  17. Heat transfer modelling of pulsed laser-tissue interaction

    Science.gov (United States)

    Urzova, J.; Jelinek, M.

    2018-03-01

    Due to their attributes, the application of medical lasers is on the rise in numerous medical fields. From a biomedical point of view, the most interesting applications are the thermal interactions and the photoablative interactions, which effectively remove tissue without excessive heat damage to the remaining tissue. The objective of this work is to create a theoretical model for heat transfer in the tissue following its interaction with the laser beam to predict heat transfer during medical laser surgery procedures. The dimensions of the ablated crater (shape and ablation depth) were determined by computed tomography imaging. COMSOL Multiphysics software was used for temperature modelling. The parameters of tissue and blood, such as density, specific heat capacity, thermal conductivity and diffusivity, were calculated from the chemical ratio. The parameters of laser-tissue interaction, such as absorption and reflection coefficients, were experimentally determined. The parameters of the laser beam were power density, repetition frequency, pulse length and spot dimensions. Heat spreading after laser interaction with tissue was captured using a Fluke thermal camera. The model was verified for adipose tissue, skeletal muscle tissue and heart muscle tissue.

  18. Tissue polarimetry: concepts, challenges, applications, and outlook.

    Science.gov (United States)

    Ghosh, Nirmalya; Vitkin, I Alex

    2011-11-01

    Polarimetry has a long and successful history in various forms of clear media. Driven by their biomedical potential, the use of the polarimetric approaches for biological tissue assessment has also recently received considerable attention. Specifically, polarization can be used as an effective tool to discriminate against multiply scattered light (acting as a gating mechanism) in order to enhance contrast and to improve tissue imaging resolution. Moreover, the intrinsic tissue polarimetry characteristics contain a wealth of morphological and functional information of potential biomedical importance. However, in a complex random medium-like tissue, numerous complexities due to multiple scattering and simultaneous occurrences of many scattering and polarization events present formidable challenges both in terms of accurate measurements and in terms of analysis of the tissue polarimetry signal. In order to realize the potential of the polarimetric approaches for tissue imaging and characterization/diagnosis, a number of researchers are thus pursuing innovative solutions to these challenges. In this review paper, we summarize these and other issues pertinent to the polarized light methodologies in tissues. Specifically, we discuss polarized light basics, Stokes-Muller formalism, methods of polarization measurements, polarized light modeling in turbid media, applications to tissue imaging, inverse analysis for polarimetric results quantification, applications to quantitative tissue assessment, etc.

  19. VISUALIZATION OF BIOLOGICAL TISSUE IMPEDANCE PARAMETERS

    Directory of Open Access Journals (Sweden)

    V. I. Bankov

    2016-01-01

    Full Text Available Objective. Investigation the opportunity for measurement of biological tissue impedance to visualize its parameters.Materials and methods. Studies were undertook on the experimental facility, consists of registrating measuring cell, constructed from flat inductors system, formed in oscillatory circuit, herewith investigated biological tissue is the part of this oscillatory circuit. An excitation of oscillatory circuit fulfilled by means of exciter inductor which forms impulse complex modulated electromagnetic field (ICM EMF. The measurement process and visualizations provided by set of certificated instruments: a digital oscillograph AKTAKOM ADS-2221MV, a digital generator АКТАКОМ AWG-4150 (both with software and a gauge RLC E7-22. Comparative dynamic studies of fixed volume and weight pig’s blood, adipose tissue, muscular tissue impedance were conducted by contact versus contactless methods. Contactless method in contrast to contact method gives opportunity to obtain the real morphological visualization of biological tissue irrespective of their nature.Results. Comparison of contact and contactless methods of impedance measurement shows that the inductance to capacitance ratio X(L / X(C was equal: 17 – for muscular tissue, 4 – for blood, 1 – for adipose tissue. It demonstrates the technical correspondence of both impedance registration methods. If propose the base relevance of X (L and X (C parameters for biological tissue impedance so contactless measurement method for sure shows insulating properties of adipose tissue and high conductivity for blood and muscular tissue in fixed volume-weight parameters. Registration of biological tissue impedance complex parameters by contactless method with the help of induced ICM EMF in fixed volume of biological tissue uncovers the most important informative volumes to characterize morphofunctional condition of biological tissue namely X (L / X (C.Conclusion. Contactless method of biological

  20. Scalable robotic biofabrication of tissue spheroids

    International Nuclear Information System (INIS)

    Mehesz, A Nagy; Hajdu, Z; Visconti, R P; Markwald, R R; Mironov, V; Brown, J; Beaver, W; Da Silva, J V L

    2011-01-01

    Development of methods for scalable biofabrication of uniformly sized tissue spheroids is essential for tissue spheroid-based bioprinting of large size tissue and organ constructs. The most recent scalable technique for tissue spheroid fabrication employs a micromolded recessed template prepared in a non-adhesive hydrogel, wherein the cells loaded into the template self-assemble into tissue spheroids due to gravitational force. In this study, we present an improved version of this technique. A new mold was designed to enable generation of 61 microrecessions in each well of a 96-well plate. The microrecessions were seeded with cells using an EpMotion 5070 automated pipetting machine. After 48 h of incubation, tissue spheroids formed at the bottom of each microrecession. To assess the quality of constructs generated using this technology, 600 tissue spheroids made by this method were compared with 600 spheroids generated by the conventional hanging drop method. These analyses showed that tissue spheroids fabricated by the micromolded method are more uniform in diameter. Thus, use of micromolded recessions in a non-adhesive hydrogel, combined with automated cell seeding, is a reliable method for scalable robotic fabrication of uniform-sized tissue spheroids.

  1. Printing and Prototyping of Tissues and Scaffolds

    Science.gov (United States)

    Derby, Brian

    2012-11-01

    New manufacturing technologies under the banner of rapid prototyping enable the fabrication of structures close in architecture to biological tissue. In their simplest form, these technologies allow the manufacture of scaffolds upon which cells can grow for later implantation into the body. A more exciting prospect is the printing and patterning in three dimensions of all the components that make up a tissue (cells and matrix materials) to generate structures analogous to tissues; this has been termed bioprinting. Such techniques have opened new areas of research in tissue engineering and regenerative medicine.

  2. Segmentation and Quantitative Analysis of Epithelial Tissues.

    Science.gov (United States)

    Aigouy, Benoit; Umetsu, Daiki; Eaton, Suzanne

    2016-01-01

    Epithelia are tissues that regulate exchanges with the environment. They are very dynamic and can acquire virtually any shape; at the cellular level, they are composed of cells tightly connected by junctions. Most often epithelia are amenable to live imaging; however, the large number of cells composing an epithelium and the absence of informatics tools dedicated to epithelial analysis largely prevented tissue scale studies. Here we present Tissue Analyzer, a free tool that can be used to segment and analyze epithelial cells and monitor tissue dynamics.

  3. Extraintestinal heterotopic gastric tissue simulating acute appendicitis

    Institute of Scientific and Technical Information of China (English)

    Elizabeth Bender; Steven P Schmidt

    2008-01-01

    We describe the case of a 68-year-old otherwise healthy male who presented to our emergency room with signs and symptoms of acute appendicitis. Exploratory surgery revealed a normal appendix. Further examination revealed an enlarged lymph node-like mass of tissue near the appendix, in the ileocecal mesentery. This mass was removed and was found to be inflamed heterotopic gastric tissue. Although reports of heterotopic gastric tissue in the literature are common, we believe that this case represents the first report of inflamed heterotopic gastric tissue simulating appendicitis.

  4. Effect of Infrared Lasers on Corneal Tissue

    National Research Council Canada - National Science Library

    Eurell, Thomas

    2004-01-01

    .... However, using MMP-2 immunohistochemistry to detect subtle stromal remodeling, we discovered a markedly increased tissue response to nanosecond exposures when compared to millisecond exposures...

  5. Microgravity cultivation of cells and tissues

    Science.gov (United States)

    Freed, L. E.; Pellis, N.; Searby, N.; de Luis, J.; Preda, C.; Bordonaro, J.; Vunjak-Novakovic, G.

    1999-01-01

    In vitro studies of cells and tissues in microgravity, either simulated by cultivation conditions on earth or actual, during spaceflight, are expected to help identify mechanisms underlying gravity sensing and transduction in biological organisms. In this paper, we review rotating bioreactor studies of engineered skeletal and cardiovascular tissues carried out in unit gravity, a four month long cartilage tissue engineering study carried out aboard the Mir Space Station, and the ongoing laboratory development and testing of a system for cell and tissue cultivation aboard the International Space Station.

  6. Scalable robotic biofabrication of tissue spheroids

    Energy Technology Data Exchange (ETDEWEB)

    Mehesz, A Nagy; Hajdu, Z; Visconti, R P; Markwald, R R; Mironov, V [Advanced Tissue Biofabrication Center, Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC (United States); Brown, J [Department of Mechanical Engineering, Clemson University, Clemson, SC (United States); Beaver, W [York Technical College, Rock Hill, SC (United States); Da Silva, J V L, E-mail: mironovv@musc.edu [Renato Archer Information Technology Center-CTI, Campinas (Brazil)

    2011-06-15

    Development of methods for scalable biofabrication of uniformly sized tissue spheroids is essential for tissue spheroid-based bioprinting of large size tissue and organ constructs. The most recent scalable technique for tissue spheroid fabrication employs a micromolded recessed template prepared in a non-adhesive hydrogel, wherein the cells loaded into the template self-assemble into tissue spheroids due to gravitational force. In this study, we present an improved version of this technique. A new mold was designed to enable generation of 61 microrecessions in each well of a 96-well plate. The microrecessions were seeded with cells using an EpMotion 5070 automated pipetting machine. After 48 h of incubation, tissue spheroids formed at the bottom of each microrecession. To assess the quality of constructs generated using this technology, 600 tissue spheroids made by this method were compared with 600 spheroids generated by the conventional hanging drop method. These analyses showed that tissue spheroids fabricated by the micromolded method are more uniform in diameter. Thus, use of micromolded recessions in a non-adhesive hydrogel, combined with automated cell seeding, is a reliable method for scalable robotic fabrication of uniform-sized tissue spheroids.

  7. Principles, Techniques, and Applications of Tissue Microfluidics

    Science.gov (United States)

    Wade, Lawrence A.; Kartalov, Emil P.; Shibata, Darryl; Taylor, Clive

    2011-01-01

    The principle of tissue microfluidics and its resultant techniques has been applied to cell analysis. Building microfluidics to suit a particular tissue sample would allow the rapid, reliable, inexpensive, highly parallelized, selective extraction of chosen regions of tissue for purposes of further biochemical analysis. Furthermore, the applicability of the techniques ranges beyond the described pathology application. For example, they would also allow the posing and successful answering of new sets of questions in many areas of fundamental research. The proposed integration of microfluidic techniques and tissue slice samples is called "tissue microfluidics" because it molds the microfluidic architectures in accordance with each particular structure of each specific tissue sample. Thus, microfluidics can be built around the tissues, following the tissue structure, or alternatively, the microfluidics can be adapted to the specific geometry of particular tissues. By contrast, the traditional approach is that microfluidic devices are structured in accordance with engineering considerations, while the biological components in applied devices are forced to comply with these engineering presets.

  8. Medical image of the week: granulation tissue

    Directory of Open Access Journals (Sweden)

    Ganesh A

    2014-03-01

    Full Text Available A 57 year old woman presented with a tickling sensation in the back of throat and intermittent bleeding from the healing stoma one month after decannulation of her tracheostomy tube. On bronchoscopy a granuloma with surrounding granulation tissue was present in the subglottic space (Figure 1. Argon plasma coagulation (APC was performed to cauterize the granulation tissue (Figure 2. Formation of granulation tissue after tracheostomy is a common complication which can result in tracheal stenosis. APC and electrocautery using flexible bronchoscopy has been shown to safely and effectively remove the granulation tissue.

  9. Analysis of tooth tissues using Raman spectroscopy

    International Nuclear Information System (INIS)

    Timchenko, E.V.; Timchenko, P.E.; Kulabukhova, A.Yu.; Volova, L.T.; Rosenbaum, A.Yu.

    2016-01-01

    The results of experimental studies of healthy tooth tissue and tooth tissues during caries disease are presented. Features of Raman spectrum of tooth tissues during caries disease are obtained: the main changes are detected at wavenumbers 956 cm -1 .1069 cm -1 . corresponding to phosphates. and 1241 cm -1 . 1660 cm -1 . corresponding to collagen III and collagen I. respectively. Were introduced criteria allowing to detect caries and to identify weakening of tooth tissues. preceding the caries. The reliability of research results is confirmed by scanning electron microscopy. (paper)

  10. Tissue characterization using magnetic resonance elastography: preliminary results

    International Nuclear Information System (INIS)

    Kruse, S.A.; Smith, J.A.; Lawrence, A.J.; Dresner, M.A.; Manduca, A.; Greenleaf, J.F.; Ehman, R.L.

    2000-01-01

    The well-documented effectiveness of palpation as a diagnostic technique for detecting cancer and other diseases has provided motivation for developing imaging techniques for non-invasively evaluating the mechanical properties of tissue. A recently described approach for elasticity imaging, using propagating acoustic shear waves and phase-contrast MRI, has been called magnetic resonance elastography (MRE). The purpose of this work was to conduct preliminary studies to define methods for using MRE as a tool for addressing the paucity of quantitative tissue mechanical property data in the literature. Fresh animal liver and kidney tissue specimens were evaluated with MRE at multiple shear wave frequencies. The influence of specimen temperature and orientation on measurements of stiffness was studied in skeletal muscle. The results demonstrated that all of the materials tested (liver, kidney, muscle and tissue-simulating gel) exhibit systematic dependence of shear stiffness on shear rate. These data are consistent with a viscoelastic model of tissue mechanical properties, allowing calculation of two independent tissue properties from multiple-frequency MRE data: shear modulus and shear viscosity. The shear stiffness of tissue can be substantially affected by specimen temperature. The results also demonstrated evidence of shear anisotropy in skeletal muscle but not liver tissue. The measured shear stiffness in skeletal muscle was found to depend on both the direction of propagation and polarization of the shear waves. (author)

  11. Effects of tissue mechanical properties on susceptibility to histotripsy-induced tissue damage

    Science.gov (United States)

    Vlaisavljevich, Eli; Kim, Yohan; Owens, Gabe; Roberts, William; Cain, Charles; Xu, Zhen

    2014-01-01

    Histotripsy is a non-invasive tissue ablation method capable of fractionating tissue by controlling acoustic cavitation. To determine the fractionation susceptibility of various tissues, we investigated histotripsy-induced damage on tissue phantoms and ex vivo tissues with different mechanical strengths. A histotripsy bubble cloud was formed at tissue phantom surfaces using 5-cycle long ultrasound pulses with peak negative pressure of 18 MPa and PRFs of 10, 100, and 1000 Hz. Results showed significantly smaller lesions were generated in tissue phantoms of higher mechanical strength. Histotripsy was also applied to 43 different ex vivo porcine tissues with a wide range of mechanical properties. Gross morphology demonstrated stronger tissues with higher ultimate stress, higher density, and lower water content were more resistant to histotripsy damage in comparison to weaker tissues. Based on these results, a self-limiting vessel-sparing treatment strategy was developed in an attempt to preserve major vessels while fractionating the surrounding target tissue. This strategy was tested in porcine liver in vivo. After treatment, major hepatic blood vessels and bile ducts remained intact within a completely fractionated liver volume. These results identify varying susceptibilities of tissues to histotripsy therapy and provide a rational basis to optimize histotripsy parameters for treatment of specific tissues.

  12. Mechanical homeostasis regulating adipose tissue volume

    Directory of Open Access Journals (Sweden)

    Svedman Paul

    2007-09-01

    Full Text Available Abstract Background The total body adipose tissue volume is regulated by hormonal, nutritional, paracrine, neuronal and genetic control signals, as well as components of cell-cell or cell-matrix interactions. There are no known locally acting homeostatic mechanisms by which growing adipose tissue might adapt its volume. Presentation of the hypothesis Mechanosensitivity has been demonstrated by mesenchymal cells in tissue culture. Adipocyte differentiation has been shown to be inhibited by stretching in vitro, and a pathway for the response has been elucidated. In humans, intermittent stretching of skin for reconstructional purposes leads to thinning of adipose tissue and thickening of epidermis – findings matching those observed in vitro in response to mechanical stimuli. Furthermore, protracted suspension of one leg increases the intermuscular adipose tissue volume of the limb. These findings may indicate a local homeostatic adipose tissue volume-regulating mechanism based on movement-induced reduction of adipocyte differentiation. This function might, during evolution, have been of importance in confined spaces, where overgrowth of adipose tissue could lead to functional disturbance, as for instance in the turtle. In humans, adipose tissue near muscle might in particular be affected, for instance intermuscularly, extraperitoneally and epicardially. Mechanical homeostasis might also contribute to protracted maintainment of soft tissue shape in the face and neck region. Testing of the hypothesis Assessment of messenger RNA-expression of human adipocytes following activity in adjacent muscle is planned, and study of biochemical and volumetric adipose tissue changes in man are proposed. Implications of the hypothesis The interpretation of metabolic disturbances by means of adipose tissue might be influenced. Possible applications in the head and neck were discussed.

  13. Tissue banking for management of nuclear casualties

    International Nuclear Information System (INIS)

    Singh, Rita

    2014-01-01

    The proliferation of nuclear material and technology has made the acquisition and adversarial use more probable than ever. Devastating medical consequences would follow a nuclear detonation due to the thermal, blast and radiation effects of the weapon. Atomic explosions at Hiroshima and Nagasaki demonstrated the human agonies on vast scale. A full range of medical modalities are required to decrease the morbidity and mortality as a result of the use of nuclear weapons. Biological tissues from human donor like bone, skin, amniotic membrane and other soft tissues can be used for repair or reconstruction of the injured part of the body. Tissues from human donor can be processed and banked for orthopaedic, spinal, trauma and other surgical procedures. Processed tissues can be provided by the tissue banks and can be of great assistance in the treatment of injuries due to the nuclear weapon. The use of allograft tissue avoids the donor site morbidity and reduces the operating time, expense and trauma associated with the acquisition of autografts. Further, allografts have the added advantage of being available in large quantities. This has led to a global increase in allogeneic transplantation and development of tissue banking. The aim of the tissue bank is to provide a wide range of processed biological tissues free from any transmissible disease, that help to restore the growth and function of the damaged tissues. Skin dressings or skin substitutes like allograft skin, xenograft skin and amniotic membrane can be used for the treatment of thermal burns and radiation induced skin injuries. Bone allografts can be used for reconstructive approaches to the skeletal system. Tissue banking would thus ensure health care to the military personnel and population following a nuclear detonation. (author)

  14. Retention of metabolized antimony, cobalt, iodine, mercury, selenium and zinc in various tissues of the rat following freeze-drying and oven-drying at different temperatures

    International Nuclear Information System (INIS)

    Iyengar, G.V.; Kasperek, K.; Feinendegen, L.E.

    1977-01-01

    Loss of Sb, Co, I, Hg, Se, and Zn during freeze-drying and oven-drying at 80 0 C, 105 0 C, and 120 0 C were studied in rat tissues that contained metabolized radioactive isotopes. No loss was observed for any of the 6 elements on freeze-drying. However, tissue-specific differences were observed in many cases for the elements Hg, Se, I, and Sb on oven-drying. Although the losses were statistically significant, they remained in most cases between 2 and 10%, with the exception of Hg at 120 0 C, where the losses in some of the tissues were unpredictable. With respect to urine, freeze-drying and oven-drying at 80 0 C were found to be relatively safe for the elements Hg and I. At 105 0 C and above, serious loss of Hg was observed. For Se only freeze-drying was found to be safe

  15. Lasers in Esthetic Dentistry: Soft Tissue Photobiomodulation, Hard Tissue Decontamination, and Ceramics Conditioning

    Directory of Open Access Journals (Sweden)

    Karen Müller Ramalho

    2014-01-01

    Full Text Available The increasing concern and the search for conservative dental treatments have resulted in the development of several new technologies. Low and high power lasers can be cited as one of these new technologies. Low power lasers act at cellular level leading to pain reduction, modulation of inflammation, and improvement of tissue healing. High power lasers act by increasing temperature and have the potential to promote microbial reduction and ablation of hard and soft tissues. The clinical application of both low and high power lasers requires specific knowledge concerning laser interaction with biological tissues, so that the correct irradiation protocol can be established. The present case report describes the clinical steps of two metal-ceramic crowns development in a 60-year-old patient. Three different laser wavelengths were applied throughout the treatment with different purposes: Nd:YAG laser (1,064 nm for dentin decontamination, diode (660 nm for soft tissue biomodulation, and Er:YAG laser (2,940 nm for inner ceramic surface conditioning. Lasers were successfully applied in the present case report as coadjutant in the treatment. This coadjutant technology can be a potential tool to assist treatment to reach the final success.

  16. 2010 Great Lakes Human Health Fish Tissue Study Fish Tissue Data Dictionary

    Science.gov (United States)

    The Office of Science and Technology (OST) is providing the fish tissue results from the 2010 Great Lakes Human Health Fish Tissue Study (GLHHFTS). This document includes the “data dictionary” for Mercury, PFC, PBDE and PCBs.

  17. Adipose tissue-derived stem cells in oral mucosa tissue engineering ...

    African Journals Online (AJOL)

    Jane

    2011-10-10

    Oct 10, 2011 ... stem cells (ADSCs) may play an important role in this field. In this research ..... Adipose tissue is derived from embryonic mesodermal precursors and .... Clonogenic multipotent stem cells in human adipose tissue differentiate ...

  18. Intermittent straining accelerates the development of tissue properties in engineered heart valve tissue

    NARCIS (Netherlands)

    Rubbens, M.P.; Mol, A.; Boerboom, R.A.; Bank, R.A.; Baaijens, F.P.T.; Bouten, C.V.C.

    2009-01-01

    Tissue-engineered heart valves lack sufficient amounts of functionally organized structures and consequently do not meet in vivo mechanical demands. To optimize tissue architecture and hence improve mechanical properties, various in vitro mechanical conditioning protocols have been proposed, of

  19. Walnut tissue culture: research and field applications

    Science.gov (United States)

    2004-01-01

    Vitrotech Biotecnologia Vegetal began researching propagating Juglans regia (English walnut) and various Juglans hybrids by tissue culture in 1993 and has operated on a commercial scale since 1996. Since this time, more than one and a half million walnuts of different species have been propagated and field planted. Tissue cultured...

  20. Degradable Adhesives for Surgery and Tissue Engineering.

    Science.gov (United States)

    Bhagat, Vrushali; Becker, Matthew L

    2017-10-09

    This review highlights the research on degradable polymeric tissue adhesives for surgery and tissue engineering. Included are a comprehensive listing of specific uses, advantages, and disadvantages of different adhesive groups. A critical evaluation of challenges affecting the development of next generation materials is also discussed, and insights into the outlook of the field are explored.

  1. Development of multilayer constructs for tissue engineering

    NARCIS (Netherlands)

    Bettahalli, N. M. S.; Groen, N.; Steg, H.; Unadkat, H.; de Boer, J.; van Blitterswijk, C. A.; Wessling, M.; Stamatialis, D.

    The rapidly developing field of tissue engineering produces living substitutes that restore, maintain or improve the function of tissues or organs. In contrast to standard therapies, the engineered products become integrated within the patient, affording a potentially permanent and specific cure of

  2. Development of multilayer constructs for tissue engineering

    NARCIS (Netherlands)

    Bettahalli Narasimha, M.S.; Groen, N.; Steg, H.; Unadkat, H.V.; de Boer, Jan; van Blitterswijk, Clemens; Wessling, Matthias; Stamatialis, Dimitrios

    2014-01-01

    The rapidly developing field of tissue engineering produces living substitutes that restore, maintain or improve the function of tissues or organs. In contrast to standard therapies, the engineered products become integrated within the patient, affording a potentially permanent and specific cure of

  3. Observations of needle-tissue interactions

    NARCIS (Netherlands)

    Misra, Sarthak; Reed, Kyle B.; Ramesh, K.T.; Okamura, Allison M.

    2009-01-01

    Needles with asymmetric bevel tips naturally bend when they are inserted into soft tissue. In this study, we present an analytical model for the loads developed at the bevel tip during needle-tissue interaction. The model calculates the loads based on the geometry of the bevel edge and gel material

  4. 3D bioprinting for vascularized tissue fabrication

    Science.gov (United States)

    Richards, Dylan; Jia, Jia; Yost, Michael; Markwald, Roger; Mei, Ying

    2016-01-01

    3D bioprinting holds remarkable promise for rapid fabrication of 3D tissue engineering constructs. Given its scalability, reproducibility, and precise multi-dimensional control that traditional fabrication methods do not provide, 3D bioprinting provides a powerful means to address one of the major challenges in tissue engineering: vascularization. Moderate success of current tissue engineering strategies have been attributed to the current inability to fabricate thick tissue engineering constructs that contain endogenous, engineered vasculature or nutrient channels that can integrate with the host tissue. Successful fabrication of a vascularized tissue construct requires synergy between high throughput, high-resolution bioprinting of larger perfusable channels and instructive bioink that promotes angiogenic sprouting and neovascularization. This review aims to cover the recent progress in the field of 3D bioprinting of vascularized tissues. It will cover the methods of bioprinting vascularized constructs, bioink for vascularization, and perspectives on recent innovations in 3D printing and biomaterials for the next generation of 3D bioprinting for vascularized tissue fabrication. PMID:27230253

  5. Stem Cells in Tissue Repair and Regeneration

    OpenAIRE

    Falanga, Vincent

    2012-01-01

    The field of tissue repair and wound healing has blossomed in the last 30 years. We have gone from recombinant growth factors, to living tissue engineering constructs, to stem cells. The task now is to pursue true regeneration, thus achieving full restoration of structures and their function.

  6. Biomechanics and mechanobiology in functional tissue engineering

    NARCIS (Netherlands)

    Guilak, F.; Butler, D.L.; Goldstein, S.A.; Baaijens, F.P.T.

    2014-01-01

    The field of tissue engineering continues to expand and mature, and several products are now in clinical use, with numerous other preclinical and clinical studies underway. However, specific challenges still remain in the repair or regeneration of tissues that serve a predominantly biomechanical

  7. Scientific and industrial status of tissue engineering

    African Journals Online (AJOL)

    SERVER

    2007-12-28

    Dec 28, 2007 ... with artificial materials e.g. replacement of aortic artery with Dacron. ... Employment of living cells to replace the lost tissue, which is the basis of tissue ...... by the US National Intelligence Council, the Intelligence. Technology ...

  8. Electromagnetic pulse distortion in living tissue

    NARCIS (Netherlands)

    Lepelaars, E.S.A.M.

    1996-01-01

    Insight into the distortion of electromagnetic (EM) signals in living tissue is important for optimising medical applications. To obtain this insight, field calculations have been carried out for a plane-stratified configuration of air, skin, fat, muscle and bone tissue. In this configuration, an EM

  9. Lung tissue mechanics as an emergent phenomenon.

    Science.gov (United States)

    Suki, Béla; Bates, Jason H T

    2011-04-01

    The mechanical properties of lung parenchymal tissue are both elastic and dissipative, as well as being highly nonlinear. These properties cannot be fully understood, however, in terms of the individual constituents of the tissue. Rather, the mechanical behavior of lung tissue emerges as a macroscopic phenomenon from the interactions of its microscopic components in a way that is neither intuitive nor easily understood. In this review, we first consider the quasi-static mechanical behavior of lung tissue and discuss computational models that show how smooth nonlinear stress-strain behavior can arise through a percolation-like process in which the sequential recruitment of collagen fibers with increasing strain causes them to progressively take over the load-bearing role from elastin. We also show how the concept of percolation can be used to link the pathologic progression of parenchymal disease at the micro scale to physiological symptoms at the macro scale. We then examine the dynamic mechanical behavior of lung tissue, which invokes the notion of tissue resistance. Although usually modeled phenomenologically in terms of collections of springs and dashpots, lung tissue viscoelasticity again can be seen to reflect various types of complex dynamic interactions at the molecular level. Finally, we discuss the inevitability of why lung tissue mechanics need to be complex.

  10. Effect of UV laser irradiation on tissue

    International Nuclear Information System (INIS)

    Nakayama, Takeyoshi; Kubo, Uichi

    1992-01-01

    Laser-tissue interactions have been investigated through Electron Probe Micro Analysis (EPMA), UV-visible optical absorption and Fourier Transform Infrared Spectroscopy (FTIR). Three excimer lasers, ArF, KrF and XeCl, were used to irradiate tissue; cow thighbone and gelatin thin film. Features of UV laser irradiation are described. (author)

  11. A flexible infrared sensor for tissue oximetry

    DEFF Research Database (Denmark)

    Petersen, Søren Dahl; Thyssen, Anders; Engholm, Mathias

    2013-01-01

    We present a flexible infrared sensor for use in tissue oximetry with the aim of treating prematurely born infants. The sensor will detect the oxygen saturation in brain tissue through near infrared spectroscopy. The sensor itself consists of several individual silicon photo detectors fully...

  12. Taurine content of tissues of irradiated rats

    International Nuclear Information System (INIS)

    Akhalaya, M.Ya.; Bogatyrev, G.P.; Kudryashov, Yu.B.; Yartsev, E.I.

    1976-01-01

    The taurine content of tissues (liver, stomach, small intestine and spleen) of rats irradiated with doses of 700 and 450 rads has been studied. Phase changes have been found in the taurine content of radiosensitive tissues in the course of radiation injury development

  13. PATMA: parser of archival tissue microarray

    Directory of Open Access Journals (Sweden)

    Lukasz Roszkowiak

    2016-12-01

    Full Text Available Tissue microarrays are commonly used in modern pathology for cancer tissue evaluation, as it is a very potent technique. Tissue microarray slides are often scanned to perform computer-aided histopathological analysis of the tissue cores. For processing the image, splitting the whole virtual slide into images of individual cores is required. The only way to distinguish cores corresponding to specimens in the tissue microarray is through their arrangement. Unfortunately, distinguishing the correct order of cores is not a trivial task as they are not labelled directly on the slide. The main aim of this study was to create a procedure capable of automatically finding and extracting cores from archival images of the tissue microarrays. This software supports the work of scientists who want to perform further image processing on single cores. The proposed method is an efficient and fast procedure, working in fully automatic or semi-automatic mode. A total of 89% of punches were correctly extracted with automatic selection. With an addition of manual correction, it is possible to fully prepare the whole slide image for extraction in 2 min per tissue microarray. The proposed technique requires minimum skill and time to parse big array of cores from tissue microarray whole slide image into individual core images.

  14. Pressure induced deep tissue injury explained

    NARCIS (Netherlands)

    Oomens, C.W.J.; Bader, D.L.; Loerakker, S.; Baaijens, F.P.T.

    The paper describes the current views on the cause of a sub-class of pressure ulcers known as pressure induced deep tissue injury (DTI). A multi-scale approach was adopted using model systems ranging from single cells in culture, tissue engineered muscle to animal studies with small animals. This

  15. General Information about Adult Soft Tissue Sarcoma

    Science.gov (United States)

    ... deep (in the muscle and may be in connective or subcutaneous tissue). In stage IB , the tumor is low-grade (likely to grow and spread ... deep (in the muscle and may be in connective or subcutaneous tissue). In stage IIB , the tumor is mid-grade (somewhat likely to grow and ...

  16. Stages of Adult Soft Tissue Sarcoma

    Science.gov (United States)

    ... deep (in the muscle and may be in connective or subcutaneous tissue). In stage IB , the tumor is low-grade (likely to grow and spread ... deep (in the muscle and may be in connective or subcutaneous tissue). In stage IIB , the tumor is mid-grade (somewhat likely to grow and ...

  17. Nanomaterials for Craniofacial and Dental Tissue Engineering.

    Science.gov (United States)

    Li, G; Zhou, T; Lin, S; Shi, S; Lin, Y

    2017-07-01

    Tissue engineering shows great potential as a future treatment for the craniofacial and dental defects caused by trauma, tumor, and other diseases. Due to the biomimetic features and excellent physiochemical properties, nanomaterials are of vital importance in promoting cell growth and stimulating tissue regeneration in tissue engineering. For craniofacial and dental tissue engineering, the frequently used nanomaterials include nanoparticles, nanofibers, nanotubes, and nanosheets. Nanofibers are attractive for cell invasion and proliferation because of their resemblance to extracellular matrix and the presence of large pores, and they have been used as scaffolds in bone, cartilage, and tooth regeneration. Nanotubes and nanoparticles improve the mechanical and chemical properties of scaffold, increase cell attachment and migration, and facilitate tissue regeneration. In addition, nanofibers and nanoparticles are also used as a delivery system to carry the bioactive agent in bone and tooth regeneration, have better control of the release speed of agent upon degradation of the matrix, and promote tissue regeneration. Although applications of nanomaterials in tissue engineering remain in their infancy with numerous challenges to face, the current results indicate that nanomaterials have massive potential in craniofacial and dental tissue engineering.

  18. Adipose Tissue Biology: An Update Review

    Directory of Open Access Journals (Sweden)

    Anna Meiliana

    2009-12-01

    Full Text Available BACKGROUND: Obesity is a major health problem in most countries in the world today. It increases the risk of diabetes, heart disease, fatty liver and some form of cancer. Adipose tissue biology is currently one of the “hot” areas of biomedical science, as fundamental for the development of novel therapeutics for obesity and its related disorders.CONTENT: Adipose tissue consist predominantly of adipocytes, adipose-derived stromal cells (ASCs, vascular endothelial cells, pericytes, fibroblast, macrophages, and extracellular matrix. Adipose tissue metabolism is extremely dynamic, and the supply of and removal of substrates in the blood is acutely regulated according to the nutritional state. Adipose tissue possesses the ability to a very large extent to modulate its own metabolic activities including differentiation of new adipocytes and production of blood vessels as necessary to accommodate increasing fat stores. At the same time, adipocytes signal to other tissue to regulate their energy metabolism in accordance with the body's nutritional state. Ultimately adipocyte fat stores have to match the body's overall surplus or deficit of energy. Obesity causes adipose tissue dysfunction and results in obesity-related disorders. SUMMARY: It is now clear that adipose tissue is a complex and highly active metabolic and endocrine organ. Undestanding the molecular mechanisms underlying obesity and its associated disease cluster is also of great significance as the need for new and more effective therapeutic strategies is more urgent than ever.  KEYWORDS: obesity, adipocyte, adipose, tissue, adipogenesis, angiogenesis, lipid droplet, lipolysis, plasticity, dysfunction.

  19. NMR imaging of soft tissue tumors

    International Nuclear Information System (INIS)

    Laval-Jeantet, M.; Tobolsk, F.; Delepine, N.; Delepine, G.; Roger, B.; Cabanis, E.A.

    1986-01-01

    Preliminary findings on NMR imaging of 30 soft tissue tumors demonstrated the indispensable value of this examination (particularly when a surface antenna is used) for preoperative investigation and diagnosis of tumoral recurrence when compared with other radiologic techniques. The possible potential of NMR imaging for characterization of tissues, apart from lipoma or liposarcoma, cannot be evaluated at the present time [fr

  20. Protein signature of lung cancer tissues.

    Directory of Open Access Journals (Sweden)

    Michael R Mehan

    Full Text Available Lung cancer remains the most common cause of cancer-related mortality. We applied a highly multiplexed proteomic technology (SOMAscan to compare protein expression signatures of non small-cell lung cancer (NSCLC tissues with healthy adjacent and distant tissues from surgical resections. In this first report of SOMAscan applied to tissues, we highlight 36 proteins that exhibit the largest expression differences between matched tumor and non-tumor tissues. The concentrations of twenty proteins increased and sixteen decreased in tumor tissue, thirteen of which are novel for NSCLC. NSCLC tissue biomarkers identified here overlap with a core set identified in a large serum-based NSCLC study with SOMAscan. We show that large-scale comparative analysis of protein expression can be used to develop novel histochemical probes. As expected, relative differences in protein expression are greater in tissues than in serum. The combined results from tissue and serum present the most extensive view to date of the complex changes in NSCLC protein expression and provide important implications for diagnosis and treatment.

  1. Collecting and Storing Tissue, Blood, and Bone Marrow Samples From Patients With Rhabdomyosarcoma or Other Soft Tissue Sarcoma

    Science.gov (United States)

    2017-12-11

    Adult Rhabdomyosarcoma; Childhood Desmoplastic Small Round Cell Tumor; Chordoma; Desmoid Tumor; Metastatic Childhood Soft Tissue Sarcoma; Nonmetastatic Childhood Soft Tissue Sarcoma; Previously Treated Childhood Rhabdomyosarcoma; Previously Untreated Childhood Rhabdomyosarcoma; Recurrent Adult Soft Tissue Sarcoma; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Soft Tissue Sarcoma; Stage I Adult Soft Tissue Sarcoma; Stage II Adult Soft Tissue Sarcoma; Stage III Adult Soft Tissue Sarcoma; Stage IV Adult Soft Tissue Sarcoma

  2. Bone Marrow Adipose Tissue: To Be or Not To Be a Typical Adipose Tissue?

    OpenAIRE

    Hardouin, Pierre; Rharass, Tareck; Lucas, Stéphanie

    2016-01-01

    Bone marrow adipose tissue (BMAT) emerges as a distinct fat depot whose importance has been proved in the bone–fat interaction. Indeed, it is well recognized that adipokines and free fatty acids released by adipocytes can directly or indirectly interfere with cells of bone remodeling or hematopoiesis. In pathological states, such as osteoporosis, each of adipose tissues – subcutaneous white adipose tissue (WAT), visceral WAT, brown adipose tissue (BAT), and BMAT – is differently associated wi...

  3. The tissue injury and repair in cancer radiotherapy. A concept of tissue architecture and radio sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Matsuzawa, T [Tohoku Univ., Sendai (Japan). Research Inst. for Tuberculosis, Leprosy and Cancer

    1975-06-01

    One of the difficulties in cancer radiotherapy arises from the fact that the tissue tolerance dose is much smaller than the tumor lethal dose. In our opinion the former depends upon the tolerance of the endothelial cell of the blood vessel in the normal tissue. In this introduction, a new concept regarding the estimation of tissue radiosensitivity was described, and the possible significance of the mode of radiation injury and the repair capability of normal tissue in the cancer radiotheraphy was discussed.

  4. The Adipose Tissue in Farm Animals

    DEFF Research Database (Denmark)

    Sauerwein, Helga; Bendixen, Emoke; Restelli, Laura

    2014-01-01

    and immune cells. The scientific interest in adipose tissue is largely based on the worldwide increasing prevalence of obesity in humans; in contrast, obesity is hardly an issue for farmed animals that are fed according to their well-defined needs. Adipose tissue is nevertheless of major importance...... in these animals, as the adipose percentage of the bodyweight is a major determinant for the efficiency of transferring nutrients from feed into food products and thus for the economic value from meat producing animals. In dairy animals, the importance of adipose tissue is based on its function as stromal...... and metabolic disorders. We herein provide a general overview of adipose tissue functions and its importance in farm animals. This review will summarize recent achievements in farm animal adipose tissue proteomics, mainly in cattle and pigs, but also in poultry, i.e. chicken and in farmed fish. Proteomics...

  5. Nonmuscle Tissues Contribution to Cancer Cachexia

    Directory of Open Access Journals (Sweden)

    Josep M. Argilés

    2015-01-01

    Full Text Available Cachexia is a syndrome associated with cancer, characterized by body weight loss, muscle and adipose tissue wasting, and inflammation, being often associated with anorexia. In spite of the fact that muscle tissue represents more than 40% of body weight and seems to be the main tissue involved in the wasting that occurs during cachexia, recent developments suggest that tissues/organs such as adipose (both brown and white, brain, liver, gut, and heart are directly involved in the cachectic process and may be responsible for muscle wasting. This suggests that cachexia is indeed a multiorgan syndrome. Bearing all this in mind, the aim of the present review is to examine the impact of nonmuscle tissues in cancer cachexia.

  6. Tissue and Organ 3D Bioprinting.

    Science.gov (United States)

    Xia, Zengmin; Jin, Sha; Ye, Kaiming

    2018-02-01

    Three-dimensional (3D) bioprinting enables the creation of tissue constructs with heterogeneous compositions and complex architectures. It was initially used for preparing scaffolds for bone tissue engineering. It has recently been adopted to create living tissues, such as cartilage, skin, and heart valve. To facilitate vascularization, hollow channels have been created in the hydrogels by 3D bioprinting. This review discusses the state of the art of the technology, along with a broad range of biomaterials used for 3D bioprinting. It provides an update on recent developments in bioprinting and its applications. 3D bioprinting has profound impacts on biomedical research and industry. It offers a new way to industrialize tissue biofabrication. It has great potential for regenerating tissues and organs to overcome the shortage of organ transplantation.

  7. Aloe Vera for Tissue Engineering Applications

    Directory of Open Access Journals (Sweden)

    Shekh Rahman

    2017-02-01

    Full Text Available Aloe vera, also referred as Aloe barbadensis Miller, is a succulent plant widely used for biomedical, pharmaceutical and cosmetic applications. Aloe vera has been used for thousands of years. However, recent significant advances have been made in the development of aloe vera for tissue engineering applications. Aloe vera has received considerable attention in tissue engineering due to its biodegradability, biocompatibility, and low toxicity properties. Aloe vera has been reported to have many biologically active components. The bioactive components of aloe vera have effective antibacterial, anti-inflammatory, antioxidant, and immune-modulatory effects that promote both tissue regeneration and growth. The aloe vera plant, its bioactive components, extraction and processing, and tissue engineering prospects are reviewed in this article. The use of aloe vera as tissue engineering scaffolds, gels, and films is discussed, with a special focus on electrospun nanofibers.

  8. Studying cytokinesis in Drosophila epithelial tissues.

    Science.gov (United States)

    Pinheiro, D; Bellaïche, Y

    2017-01-01

    Epithelial tissue cohesiveness is ensured through cell-cell junctions that maintain both adhesion and mechanical coupling between neighboring cells. During development, epithelial tissues undergo intensive cell proliferation. Cell division, and particularly cytokinesis, is coupled to the formation of new adhesive contacts, thereby preserving tissue integrity and propagating cell polarity. Remarkably, the geometry of the new interfaces is determined by the combined action of the dividing cell and its neighbors. To further understand the interplay between the dividing cell and its neighbors, as well as the role of cell division for tissue morphogenesis, it is important to analyze cytokinesis in vivo. Here we present methods to perform live imaging of cell division in Drosophila epithelial tissues and discuss some aspects of image processing and analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Microwave processing of gustatory tissues for immunohistochemistry

    Science.gov (United States)

    Bond, Amanda; Kinnamon, John C.

    2013-01-01

    We use immunohistochemistry to study taste cell structure and function as a means to elucidate how taste receptor cells communicate with nerve fibers and adjacent taste cells. This conventional method, however, is time consuming. In the present study we used taste buds from rat circumvallate papillae to compare conventional immunohistochemical tissue processing with microwave processing for the colocalization of several biochemical pathway markers (PLCβ2, syntaxin-1, IP3R3, α-gustducin) and the nuclear stain, Sytox. The results of our study indicate that in microwave versus conventional immunocytochemistry: (1) fixation quality is improved; (2) the amount of time necessary for processing tissue is decreased; (3) antigen retrieval is no longer needed; (4) image quality is superior. In sum, microwave tissue processing of gustatory tissues is faster and superior to conventional immunohistochemical tissue processing for many applications. PMID:23473796

  10. Biological aspects of tissue-engineered cartilage.

    Science.gov (United States)

    Hoshi, Kazuto; Fujihara, Yuko; Yamawaki, Takanori; Harai, Motohiro; Asawa, Yukiyo; Hikita, Atsuhiko

    2018-04-01

    Cartilage regenerative medicine has been progressed well, and it reaches the stage of clinical application. Among various techniques, tissue engineering, which incorporates elements of materials science, is investigated earnestly, driven by high clinical needs. The cartilage tissue engineering using a poly lactide scaffold has been exploratorily used in the treatment of cleft lip-nose patients, disclosing good clinical results during 3-year observation. However, to increase the reliability of this treatment, not only accumulation of clinical evidence on safety and usefulness of the tissue-engineered products, but also establishment of scientific background on biological mechanisms, are regarded essential. In this paper, we reviewed recent trends of cartilage tissue engineering in clinical practice, summarized experimental findings on cellular and matrix changes during the cartilage regeneration, and discussed the importance of further studies on biological aspects of tissue-engineered cartilage, especially by the histological and the morphological methods.

  11. Multispectral tissue characterization for intestinal anastomosis optimization

    Science.gov (United States)

    Cha, Jaepyeong; Shademan, Azad; Le, Hanh N. D.; Decker, Ryan; Kim, Peter C. W.; Kang, Jin U.; Krieger, Axel

    2015-10-01

    Intestinal anastomosis is a surgical procedure that restores bowel continuity after surgical resection to treat intestinal malignancy, inflammation, or obstruction. Despite the routine nature of intestinal anastomosis procedures, the rate of complications is high. Standard visual inspection cannot distinguish the tissue subsurface and small changes in spectral characteristics of the tissue, so existing tissue anastomosis techniques that rely on human vision to guide suturing could lead to problems such as bleeding and leakage from suturing sites. We present a proof-of-concept study using a portable multispectral imaging (MSI) platform for tissue characterization and preoperative surgical planning in intestinal anastomosis. The platform is composed of a fiber ring light-guided MSI system coupled with polarizers and image analysis software. The system is tested on ex vivo porcine intestine tissue, and we demonstrate the feasibility of identifying optimal regions for suture placement.

  12. Aloe Vera for Tissue Engineering Applications.

    Science.gov (United States)

    Rahman, Shekh; Carter, Princeton; Bhattarai, Narayan

    2017-02-14

    Aloe vera, also referred as Aloe barbadensis Miller, is a succulent plant widely used for biomedical, pharmaceutical and cosmetic applications. Aloe vera has been used for thousands of years. However, recent significant advances have been made in the development of aloe vera for tissue engineering applications. Aloe vera has received considerable attention in tissue engineering due to its biodegradability, biocompatibility, and low toxicity properties. Aloe vera has been reported to have many biologically active components. The bioactive components of aloe vera have effective antibacterial, anti-inflammatory, antioxidant, and immune-modulatory effects that promote both tissue regeneration and growth. The aloe vera plant, its bioactive components, extraction and processing, and tissue engineering prospects are reviewed in this article. The use of aloe vera as tissue engineering scaffolds, gels, and films is discussed, with a special focus on electrospun nanofibers.

  13. Assessment of tissue viability by polarization spectroscopy

    Science.gov (United States)

    Nilsson, G.; Anderson, C.; Henricson, J.; Leahy, M.; O'Doherty, J.; Sjöberg, F.

    2008-09-01

    A new and versatile method for tissue viability imaging based on polarization spectroscopy of blood in superficial tissue structures such as the skin is presented in this paper. Linearly polarized light in the visible wavelength region is partly reflected directly by the skin surface and partly diffusely backscattered from the dermal tissue matrix. Most of the directly reflected light preserves its polarization state while the light returning from the deeper tissue layers is depolarized. By the use of a polarization filter positioned in front of a sensitive CCD-array, the light directly reflected from the tissue surface is blocked, while the depolarized light returning from the deeper tissue layers reaches the detector array. By separating the colour planes of the detected image, spectroscopic information about the amount of red blood cells (RBCs) in the microvascular network of the tissue under investigation can be derived. A theory that utilizes the differences in light absorption of RBCs and bloodless tissue in the red and green wavelength region forms the basis of an algorithm for displaying a colour coded map of the RBC distribution in a tissue. Using a fluid model, a linear relationship (cc. = 0.99) between RBC concentration and the output signal was demonstrated within the physiological range 0-4%. In-vivo evaluation using transepidermal application of acetylcholine by the way of iontophoresis displayed the heterogeneity pattern of the vasodilatation produced by the vasoactive agent. Applications of this novel technology are likely to be found in drug and skin care product development as well as in the assessment of skin irritation and tissue repair processes and even ultimately in a clinic case situation.

  14. Difference in volatile composition between the pericarp tissue and inner tissue of tomato (Solanum lycopersicum) fruit

    Science.gov (United States)

    Numerous studies have reported the volatile profiles in the whole fruit or pericarp tissue of tomato (Solanum lycopersicum) fruit; however, information is limited on the volatile composition in the inner tissue and its contribution to tomato aroma. For this, the pericarps and inner tissues of “Money...

  15. The importance of establishing an international network of tissue banks and regional tissue processing centers.

    Science.gov (United States)

    Morales Pedraza, Jorge

    2014-03-01

    During the past four decades, many tissue banks have been established across the world with the aim of supplying sterilized tissues for clinical use and research purposes. Between 1972 and 2005, the International Atomic Energy Agency supported the establishment of more than sixty of these tissue banks in Latin America and the Caribbean, Asia and the Pacific, Africa and Eastern Europe; promoted the use of the ionizing radiation technique for the sterilization of the processed tissues; and encouraged cooperation between the established tissue banks during the implementation of its program on radiation and tissue banking at national, regional and international levels. Taking into account that several of the established tissue banks have gained a rich experience in the procurement, processing, sterilization, storage, and medical use of sterilized tissues, it is time now to strengthen further international and regional cooperation among interested tissue banks located in different countries. The purpose of this cooperation is to share the experience gained by these banks in the procurement, processing, sterilization, storage, and used of different types of tissues in certain medical treatments and research activities. This could be done through the establishment of a network of tissue banks and a limited number of regional tissue processing centers in different regions of the world.

  16. 3D printing facilitated scaffold-free tissue unit fabrication

    International Nuclear Information System (INIS)

    Tan, Yu; Richards, Dylan J; Mei, Ying; Trusk, Thomas C; Visconti, Richard P; Yost, Michael J; Drake, Christopher J; Argraves, William Scott; Markwald, Roger R; Kindy, Mark S

    2014-01-01

    Tissue spheroids hold great potential in tissue engineering as building blocks to assemble into functional tissues. To date, agarose molds have been extensively used to facilitate fusion process of tissue spheroids. As a molding material, agarose typically requires low temperature plates for gelation and/or heated dispenser units. Here, we proposed and developed an alginate-based, direct 3D mold-printing technology: 3D printing microdroplets of alginate solution into biocompatible, bio-inert alginate hydrogel molds for the fabrication of scaffold-free tissue engineering constructs. Specifically, we developed a 3D printing technology to deposit microdroplets of alginate solution on calcium containing substrates in a layer-by-layer fashion to prepare ring-shaped 3D hydrogel molds. Tissue spheroids composed of 50% endothelial cells and 50% smooth muscle cells were robotically placed into the 3D printed alginate molds using a 3D printer, and were found to rapidly fuse into toroid-shaped tissue units. Histological and immunofluorescence analysis indicated that the cells secreted collagen type I playing a critical role in promoting cell–cell adhesion, tissue formation and maturation. (paper)

  17. Effect of 4G-alpha-glucopyranosyl hesperidin on brown fat adipose tissue- and cutaneous-sympathetic nerve activity and peripheral body temperature.

    Science.gov (United States)

    Shen, Jiao; Nakamura, Hiroyasu; Fujisaki, Yoshiyuki; Tanida, Mamoru; Horii, Yuko; Fuyuki, Risa; Takumi, Hiroko; Shiraishi, Koso; Kometani, Takashi; Nagai, Katsuya

    2009-09-11

    Changes in the activity of the autonomic nervous system are good indicators of alterations in physiological phenomena such as the body temperature, blood glucose, blood pressure. Hesperidin, a flavanone known as vitamin P, has been shown to reduce the levels of serum lipids, cholesterol, and blood pressure. However, hesperidin is not water-soluble and is not well absorbed from the intestine. G-hesperidin (4G-alpha-glucopyranosyl hesperidin) is more water-soluble and more rapidly absorbed than hesperidin. In order to clarify the functions of G-hesperidin, we examined the effects of oral administration of G-hesperidin on interscapular brown adipose tissue-sympathetic nerve activity (BAT-SNA) and cutaneous sympathetic nerve activity (CASNA) in rats weighing about 300 g. In this study, we found that oral administration of 60 mg of G-hesperidin increased the BAT-SNA but decreased the CASNA in urethane-anesthetized rats. Since an elevation in BAT-SNA increases heat production (i.e. body temperature (BT)) and a decrease in CASNA increases cutaneous perfusion, we examined whether oral administration of G-hesperidin had an effect on the peripheral BT in rats. Consequently, we observed that the subcutaneous BT at the caudal end of the back after oral administration of 60 mg of G-hesperidin was significantly higher than the subcutaneous BT after oral administration of water in conscious rats. These findings suggest that G-hesperidin enhances the BAT-SNA and suppresses the CASNA resulting in an increase in the peripheral BT, probably by an increase in the thermogenesis in the BAT and an elevation in the cutaneous blood flow.

  18. Chloride absorption by root, leaf and floral tissues of Petunia

    International Nuclear Information System (INIS)

    Jooste, J.H.

    1980-01-01

    Chloride absorption by root, leaf and floral tissues of Petunia was compared at two temperatures (30 and 2 degrees Celcius), employing different absorption periods, and in the presence and absence of a desorption treatment. All treatments revealed highest absorption by floral tissue. This was further confirmed by the absorption of chloride by the various tissues from solutions in the low (0-1 mM) and high (1-50 mM) concentration ranges. The results offer a possible explanation for the observed effects of organic and inorganic solutes on the longevity of cut flowers [af

  19. Next Generation Tissue Engineering of Orthopedic Soft Tissue-to-Bone Interfaces

    Science.gov (United States)

    Boys, Alexander J.; McCorry, Mary Clare; Rodeo, Scott; Bonassar, Lawrence J.; Estroff, Lara A.

    2017-01-01

    Soft tissue-to-bone interfaces are complex structures that consist of gradients of extracellular matrix materials, cell phenotypes, and biochemical signals. These interfaces, called entheses for ligaments, tendons, and the meniscus, are crucial to joint function, transferring mechanical loads and stabilizing orthopedic joints. When injuries occur to connected soft tissue, the enthesis must be re-established to restore function, but due to structural complexity, repair has proven challenging. Tissue engineering offers a promising solution for regenerating these tissues. This prospective review discusses methodologies for tissue engineering the enthesis, outlined in three key design inputs: materials processing methods, cellular contributions, and biochemical factors. PMID:29333332

  20. Ethical tissue: a not-for-profit model for human tissue supply.

    Science.gov (United States)

    Adams, Kevin; Martin, Sandie

    2011-02-01

    Following legislative changes in 2004 and the establishment of the Human Tissue Authority, access to human tissues for biomedical research became a more onerous and tightly regulated process. Ethical Tissue was established to meet the growing demand for human tissues, using a process that provided ease of access by researchers whilst maintaining the highest ethical and regulatory standards. The establishment of a licensed research tissue bank entailed several key criteria covering ethical, legal, financial and logistical issues being met. A wide range of stakeholders, including the HTA, University of Bradford, flagged LREC, hospital trusts and clinical groups were also integral to the process.

  1. Extravascular transport in normal and tumor tissues.

    Science.gov (United States)

    Jain, R K; Gerlowski, L E

    1986-01-01

    The transport characteristics of the normal and tumor tissue extravascular space provide the basis for the determination of the optimal dosage and schedule regimes of various pharmacological agents in detection and treatment of cancer. In order for the drug to reach the cellular space where most therapeutic action takes place, several transport steps must first occur: (1) tissue perfusion; (2) permeation across the capillary wall; (3) transport through interstitial space; and (4) transport across the cell membrane. Any of these steps including intracellular events such as metabolism can be the rate-limiting step to uptake of the drug, and these rate-limiting steps may be different in normal and tumor tissues. This review examines these transport limitations, first from an experimental point of view and then from a modeling point of view. Various types of experimental tumor models which have been used in animals to represent human tumors are discussed. Then, mathematical models of extravascular transport are discussed from the prespective of two approaches: compartmental and distributed. Compartmental models lump one or more sections of a tissue or body into a "compartment" to describe the time course of disposition of a substance. These models contain "effective" parameters which represent the entire compartment. Distributed models consider the structural and morphological aspects of the tissue to determine the transport properties of that tissue. These distributed models describe both the temporal and spatial distribution of a substance in tissues. Each of these modeling techniques is described in detail with applications for cancer detection and treatment in mind.

  2. Tylosin depletion in edible tissues of turkeys.

    Science.gov (United States)

    Montesissa, C; De Liguoro, M; Santi, A; Capolongo, F; Biancotto, G

    1999-10-01

    The depletion of tylosin residues in edible turkey tissues was followed after 3 days of administration of tylosin tartrate at 500 mg l-1 in drinking water, to 30 turkeys. Immediately after the end of the treatment (day 0) and at day 1, 3, 5 and 10 of withdrawal, six turkeys (three males and three females) per time were sacrificed and samples of edible tissues were collected. Tissue homogenates were extracted, purified and analysed by HPLC according to a method previously published for the analysis of tylosin residues in pig tissues. In all tissues, tylosin residues were already below the detection limits of 50 micrograms kg-1 at time zero. However, in several samples of tissues (skin + fat, liver, kidney, muscle), from the six turkeys sacrificed at that time, one peak corresponding to an unknown tylosin equivalent was detected at measurable concentrations. The identification of this unknown compound was performed by LC-MS/MS analysis of the extracts from incurred samples. The mass fragmentation of the compound was consistent with the structure of tylosin D (the alcoholic derivative of tylosin A), the major metabolite of tylosin previously recovered and identified in tissues and/or excreta from treated chickens, cattle and pigs.

  3. Oxygen delivery in irradiated normal tissue

    Energy Technology Data Exchange (ETDEWEB)

    Kiani, M.F.; Ansari, R. [Univ. of Tennessee Health Science Center, Memphis, TN (United States). School of Biomedical Engineering; Gaber, M.W. [St. Jude Children' s Research Hospital, Memphis, TN (United States)

    2003-03-01

    Ionizing radiation exposure significantly alters the structure and function of microvascular networks, which regulate delivery of oxygen to tissue. In this study we use a hamster cremaster muscle model to study changes in microvascular network parameters and use a mathematical model to study the effects of these observed structural and microhemodynamic changes in microvascular networks on oxygen delivery to the tissue. Our experimental observations indicate that in microvascular networks while some parameters are significantly affected by irradiation (e.g. red blood cell (RBC) transit time), others remain at the control level (e.g. RBC path length) up to 180 days post-irradiation. The results from our mathematical model indicate that tissue oxygenation patterns are significantly different in irradiated normal tissue as compared to age-matched controls and the differences are apparent as early as 3 days post irradiation. However, oxygen delivery to irradiated tissue was not found to be significantly different from age matched controls at any time between 7 days to 6 months post-irradiation. These findings indicate that microvascular late effects in irradiated normal tissue may be due to factors other than compromised tissue oxygenation. (author)

  4. Glutathione turnover in 14 rat tissues

    International Nuclear Information System (INIS)

    Potter, D.W.; Tran, T.

    1990-01-01

    GSH is a tripeptide found in all tissues and is important in maintaining cellular redox status. First-order rate constants for GSH turnover were determined for various tissues of Fischer male rats. Animals were administered [ 35 S]Cys by tail vein injection and GSH turnover was estimated by the decrease in GSH specific activity following incorporation of Cys, 1-102 hr after administration. Tissue nonprotein sulfhydryls (NPSH) were detected by Ellman's assay and compared with GSH and Cys concentrations determined by HPLC with electrochemical detection. [ 35 S]GSH was analyzed by HPLC equipped with a flow-through radioactivity detector. Although total GSH and Cys were usually slightly lower than NPSH concentrations for the tissues examined, both assay systems gave comparable results. An exception was the glandular stomach which had approximately 2-fold higher NPSH. Liver and kidney had rapid turnover rates with GSH half-lives between 2-5 hr, while heart and skeletal muscle tissue had half-lives of 80-90 hr. Turnover in the blood was slowest, with a half-life of 170 hr. Gastrointestinal tract tissues were shown to have intermediate turnover rates of the following order: glandular stomach > duodenum = small intestine = caecum = large intestine = colon > forestomach. GSH half-life in lung and skin was approximately 45 hr. These studies indicate that tissues utilize GSH at markedly different rates

  5. Trends in Tissue Engineering for Blood Vessels

    Directory of Open Access Journals (Sweden)

    Judee Grace Nemeno-Guanzon

    2012-01-01

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

  6. Multilayer scaffolds in orthopaedic tissue engineering.

    Science.gov (United States)

    Atesok, Kivanc; Doral, M Nedim; Karlsson, Jon; Egol, Kenneth A; Jazrawi, Laith M; Coelho, Paulo G; Martinez, Amaury; Matsumoto, Tomoyuki; Owens, Brett D; Ochi, Mitsuo; Hurwitz, Shepard R; Atala, Anthony; Fu, Freddie H; Lu, Helen H; Rodeo, Scott A

    2016-07-01

    The purpose of this study was to summarize the recent developments in the field of tissue engineering as they relate to multilayer scaffold designs in musculoskeletal regeneration. Clinical and basic research studies that highlight the current knowledge and potential future applications of the multilayer scaffolds in orthopaedic tissue engineering were evaluated and the best evidence collected. Studies were divided into three main categories based on tissue types and interfaces for which multilayer scaffolds were used to regenerate: bone, osteochondral junction and tendon-to-bone interfaces. In vitro and in vivo studies indicate that the use of stratified scaffolds composed of multiple layers with distinct compositions for regeneration of distinct tissue types within the same scaffold and anatomic location is feasible. This emerging tissue engineering approach has potential applications in regeneration of bone defects, osteochondral lesions and tendon-to-bone interfaces with successful basic research findings that encourage clinical applications. Present data supporting the advantages of the use of multilayer scaffolds as an emerging strategy in musculoskeletal tissue engineering are promising, however, still limited. Positive impacts of the use of next generation scaffolds in orthopaedic tissue engineering can be expected in terms of decreasing the invasiveness of current grafting techniques used for reconstruction of bone and osteochondral defects, and tendon-to-bone interfaces in near future.

  7. Tissue banking, biovigilance and the notify library.

    Science.gov (United States)

    Strong, D Michael

    2017-06-30

    This issue is dedicated to the contributions of Professor Glyn O. Phillips to the field of tissue banking and the advancement of science in general. The use of ionizing radiation to sterilize medical products drew the interest of the International Atomic Energy Agency (IAEA). A meeting in 1976 in Athens Greece to present work on the effects of sterilizing radiation doses upon the antigenic properties of proteins and biologic tissues was my first introduction of Professor Phillips and the role that he was to play in Tissue Banking (Friedlaender, in Phillips GO, Tallentine AN (eds) Radiation sterilization. Irradiated tissues and their potential clinical use. The North E. Wales Institute, Clwyd, p 128, 1978). The IAEA sponsored subsequent meetings in the Republic of Korea, Czechoslovakia and Rangoon, the later including a visit to the tissue bank by Professor Phillips. His advocacy resulted in multiple workshops and teaching opportunities in a variety of countries, one of which led to the establishment of the Asia Pacific Surgical Tissue Banking Association in 1989 (Phillips and Strong, in Phillips GO, Strong DM, von Versen R, Nather A (eds) Advances in tissue banking, vol 3. World Scientific, Singapore, pp 403-417, 1999).

  8. Mechanotransduction mechanisms in growing spherically structured tissues

    Science.gov (United States)

    Littlejohns, Euan; Dunlop, Carina M.

    2018-04-01

    There is increasing experimental interest in mechanotransduction in multi-cellular tissues as opposed to single cells. This is driven by a growing awareness of the importance of physiologically relevant three-dimensional culture and of cell–cell and cell–gel interactions in directing growth and development. The paradigm biophysical technique for investigating tissue level mechanobiology in this context is to grow model tissues in artificial gels with well-defined mechanical properties. These studies often indicate that the stiffness of the encapsulating gel can significantly alter cellular behaviours. We demonstrate here potential mechanisms linking tissue growth with stiffness-mediated mechanotransduction. We show how tissue growth in gel systems generates points at which there is a significant qualitative change in the cellular stress and strain experienced. We show analytically how these potential switching points depend on the mechanical properties of the constraining gel and predict when they will occur. Significantly, we identify distinct mechanisms that act separately in each of the stress and strain fields at different times. These observations suggest growth as a potential physical mechanism coupling gel stiffness with cellular mechanotransduction in three-dimensional tissues. We additionally show that non-proliferating areas, in the case that the constraining gel is soft compared with the tissue, will expand and contract passively as a result of growth. Central compartment size is thus seen to not be a reliable indicator on its own for growth initiation or active behaviour.

  9. Tissue banking: public awareness in Indonesia

    International Nuclear Information System (INIS)

    Nazly Hilmy

    1999-01-01

    Public awareness and acceptance on the benefit of Tissue Bank (TB) and its products in Indonesia are still very low, however four productive TBs are in operation by using mostly tissues from living donors. Except for medical doctors, nurses and experts who are involved in the establishment of the TB as well as who applied the products, almost nobody else understand what kind of bank this tissue bank is. Ethical in collecting tissues from non- living donors and using of this human tissues for safe medical application has several considerations that should be overcome, such as religious, legal and medical considerations. Legal and medical considerations are not very difficult to be faced. People are reluctant to give up by cutting off the needed tissue of a dead relative to help someone else who is suffering from a life threatening disease. Our duty is to enlighten the public about this bank by means of seminars, exposition, writings and discussions. We can use the electronic mass- media or printed one to explain the necessity of this tissue bank. We also need to involve leaders of religions, government high ranking officials as well as related Government institutions. Otherwise the tissues that are needed can only be obtained from the poor, the homeless whose health condition we do not know and no relatives who can give their permission for the taking of parts of the body. This is a very unethical way. Since January 1998, Batan Research Tissue Bank together with several hospitals in Indonesia have done four seminars, two discussions, two expositions, producing leaflets and carried out training in this matter. But it is not enough. More efforts should be done

  10. Application of polarization OCT in tissue engineering

    Science.gov (United States)

    Yang, Ying; Ahearne, Mark; Bagnaninchi, Pierre O.; Hu, Bin; Hampson, Karen; El Haj, Alicia J.

    2008-02-01

    For tissue engineering of load-bearing tissues, such as bone, tendon, cartilage, and cornea, it is critical to generate a highly organized extracellular matrix. The major component of the matrix in these tissues is collagen, which usually forms a highly hierarchical structure with increasing scale from fibril to fiber bundles. These bundles are ordered into a 3D network to withstand forces such as tensile, compressive or shear. To induce the formation of organized matrix and create a mimic body environment for tissue engineering, in particular, tendon tissue engineering, we have fabricated scaffolds with features to support the formation of uniaxially orientated collagen bundles. In addition, mechanical stimuli were applied to stimulate tissue formation and matrix organization. In parallel, we seek a nondestructive tool to monitor the changes within the constructs in response to these external stimulations. Polarizationsensitive optical coherence tomography (PSOCT) is a non-destructive technique that provides functional imaging, and possesses the ability to assess in depth the organization of tissue. In this way, an engineered tissue construct can be monitored on-line, and correlated with the application of different stimuli by PSOCT. We have constructed a PSOCT using a superluminescent diode (FWHM 52nm) in this study and produced two types of tendon constructs. The matrix structural evolution under different mechanical stimulation has been evaluated by the PSOCT. The results in this study demonstrate that PSOCT was a powerful tool enabling us to monitor non-destructively and real time the progressive changes in matrix organization and assess the impact of various stimuli on tissue orientation and growth.

  11. Viscoelastic Properties of Human Tracheal Tissues.

    Science.gov (United States)

    Safshekan, Farzaneh; Tafazzoli-Shadpour, Mohammad; Abdouss, Majid; Shadmehr, Mohammad B

    2017-01-01

    The physiological performance of trachea is highly dependent on its mechanical behavior, and therefore, the mechanical properties of its components. Mechanical characterization of trachea is key to succeed in new treatments such as tissue engineering, which requires the utilization of scaffolds which are mechanically compatible with the native human trachea. In this study, after isolating human trachea samples from brain-dead cases and proper storage, we assessed the viscoelastic properties of tracheal cartilage, smooth muscle, and connective tissue based on stress relaxation tests (at 5% and 10% strains for cartilage and 20%, 30%, and 40% for smooth muscle and connective tissue). After investigation of viscoelastic linearity, constitutive models including Prony series for linear viscoelasticity and quasi-linear viscoelastic, modified superposition, and Schapery models for nonlinear viscoelasticity were fitted to the experimental data to find the best model for each tissue. We also investigated the effect of age on the viscoelastic behavior of tracheal tissues. Based on the results, all three tissues exhibited a (nonsignificant) decrease in relaxation rate with increasing the strain, indicating viscoelastic nonlinearity which was most evident for cartilage and with the least effect for connective tissue. The three-term Prony model was selected for describing the linear viscoelasticity. Among different models, the modified superposition model was best able to capture the relaxation behavior of the three tracheal components. We observed a general (but not significant) stiffening of tracheal cartilage and connective tissue with aging. No change in the stress relaxation percentage with aging was observed. The results of this study may be useful in the design and fabrication of tracheal tissue engineering scaffolds.

  12. Evaluation of laser radiation regimes at thermal tissue destruction

    Science.gov (United States)

    Ivanov, Anatoly; Kazaryan, Mishik A.; Molodykh, E. I.; Shchetinkina, T. A.

    1996-01-01

    The existing methods of laser destruction of biotissues, widely spread in surgery and coagulation action, are based on local heat emission in the tissues after light absorption. Here we present the results of the simulation of tissues heat destruction, taking into account the influence of blood and lymph circulation on the processes of heat transfer. The problem is adapted to the case of liver tissue with tumor. A liver is considered as a capillary-porous body with internal blood circulation. Heatconductivity and tissue-blood heat transfer are considered. Heat action is assumed to be implemented with contact laser scalpel. The mathematical model consists of two inhomogeneous nonlinear equations of heatconductivity with spherical symmetry. Nonstationary temperature fields of tissue and blood are determined and the main parameters are: (1) coefficients of heatconductivity and capacitance of blood and tissue, (2) blood and tissue density, (3) total metabolic energy, (4) volume coefficient accounting for heat-exchange between tissue and blood, and (5) blood circulation velocity. The power of laser radiation was taken into account in boundary conditions set for the center of coagulated tissue volume. We also took into account the process connected with changing of substance phase (vaporization). The original computer programs allow one to solve the problem varying in a wide range of the main parameters. Reasonable agreement was found between the calculation results and the experimental data for operations on microsamples and on test animals. It was demonstrated, in particular, that liver tissue coagulation regime is achieved at 10 W laser power during 25 s. The coagulation radius of 0.7 cm with the given tumor radius of 0.5 cm corresponds to the real clinical situation in case of metastasis liver affection.

  13. Imaging in cellular and tissue engineering

    CERN Document Server

    Yu, Hanry

    2013-01-01

    Details on specific imaging modalities for different cellular and tissue engineering applications are scattered throughout articles and chapters in the literature. Gathering this information into a single reference, Imaging in Cellular and Tissue Engineering presents both the fundamentals and state of the art in imaging methods, approaches, and applications in regenerative medicine. The book underscores the broadening scope of imaging applications in cellular and tissue engineering. It covers a wide range of optical and biological applications, including the repair or replacement of whole tiss

  14. Post-radiation soft tissue sarcoma

    International Nuclear Information System (INIS)

    Tomita, Yasuhiko; Kuratsu, Shigeyuki; Myoui, Akira; Ohsawa, Masahiko; Aozasa, Katsuyuki; Uchida, Atsumasa; Ono, Keiro

    1993-01-01

    Seven patients received radiation for malignancies, and two received for benign tumors. The latency period from radiation to symptom ranged from two years to 36 years (mean 17.2 years). Post-radiation soft tissue sarcomas (PRS) comprised six cases of malignant fibrous histiocytomas, two leiomyosarcomas, and one angiosarcoma. The five-year survival of PRS was 16.7% showing a worse prognosis than spontaneously occurring soft tissue sarcomas. Seven PRS occurred superficially, and two were deeply located. Four cases occurring in the superficial tissues had histories of radiation-induced dermatitis. The radiation-induced dermatitis was suggested to be a risk factor for development of PRS. (author)

  15. Adipose tissue as an endocrine organ.

    Science.gov (United States)

    McGown, Christine; Birerdinc, Aybike; Younossi, Zobair M

    2014-02-01

    Obesity is one of the most important health challenges faced by developed countries and is increasingly affecting adolescents and children. Obesity is also a considerable risk factor for the development of numerous other chronic diseases, such as insulin resistance, type 2 diabetes, heart disease and nonalcoholic fatty liver disease. The epidemic proportions of obesity and its numerous comorbidities are bringing into focus the highly complex and metabolically active adipose tissue. Adipose tissue is increasingly being considered as a functional endocrine organ. This article discusses the endocrine effects of adipose tissue during obesity and the systemic impact of this signaling. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Progress in planta transformation without tissue culture

    International Nuclear Information System (INIS)

    Gu Yunhong; Chinese Academy of Sciences, Hefei; Qin Guangyong; Huo Yuping; Yu Zengliang

    2004-01-01

    With the development of planta genetic engineering, more emphases have been laid on convenient and high efficient genetic transformation methods. And transformation without tissue culture is a prospective direction of it. In this paper, traditional transformation methods and the methods of non-tissue culture were summarized. With the exploration and application of Arabidopsis transformation mechanism, with the use of ion beam-mediated transformation invented by Chinese scientists and the development of other transformation methods, transformation methods without tissue culture and planta genetic engineering could be improved rapidly. (authors)

  17. Quantification and validation of soft tissue deformation

    DEFF Research Database (Denmark)

    Mosbech, Thomas Hammershaimb; Ersbøll, Bjarne Kjær; Christensen, Lars Bager

    2009-01-01

    We present a model for soft tissue deformation derived empirically from 10 pig carcases. The carcasses are subjected to deformation from a known single source of pressure located at the skin surface, and the deformation is quantified by means of steel markers injected into the tissue. The steel...... markers are easy to distinguish from the surrounding soft tissue in 3D computed tomography images. By tracking corresponding markers using methods from point-based registration, we are able to accurately quantify the magnitude and propagation of the induced deformation. The deformation is parameterised...

  18. HIV Persistence in Adipose Tissue Reservoirs.

    Science.gov (United States)

    Couturier, Jacob; Lewis, Dorothy E

    2018-02-01

    The purpose of this review is to examine the evidence describing adipose tissue as a reservoir for HIV-1 and how this often expansive anatomic compartment contributes to HIV persistence. Memory CD4 T cells and macrophages, the major host cells for HIV, accumulate in adipose tissue during HIV/SIV infection of humans and rhesus macaques. Whereas HIV and SIV proviral DNA is detectable in CD4 T cells of multiple fat depots in virtually all infected humans and monkeys examined, viral RNA is less frequently detected, and infected macrophages may be less prevalent in adipose tissue. However, based on viral outgrowth assays, adipose-resident CD4 T cells are latently infected with virus that is replication-competent and infectious. Additionally, adipocytes interact with CD4 T cells and macrophages to promote immune cell activation and inflammation which may be supportive for HIV persistence. Antiviral effector cells, such as CD8 T cells and NK/NKT cells, are abundant in adipose tissue during HIV/SIV infection and typically exceed CD4 T cells, whereas B cells are largely absent from adipose tissue of humans and monkeys. Additionally, CD8 T cells in adipose tissue of HIV patients are activated and have a late differentiated phenotype, with unique TCR clonotypes of less diversity relative to blood CD8 T cells. With respect to the distribution of antiretroviral drugs in adipose tissue, data is limited, but there may be class-specific penetration of fat depots. The trafficking of infected immune cells within adipose tissues is a common event during HIV/SIV infection of humans and monkeys, but the virus may be mostly transcriptionally dormant. Viral replication may occur less in adipose tissue compared to other major reservoirs, such as lymphoid tissue, but replication competence and infectiousness of adipose latent virus are comparable to other tissues. Due to the ubiquitous nature of adipose tissue, inflammatory interactions among adipocytes and CD4 T cells and macrophages, and

  19. Vascularization of soft tissue engineering constructs

    DEFF Research Database (Denmark)

    Pimentel Carletto, Rodrigo

    with mechanical properties in the range of soft tissues has not been fully achieved. My project focused on the fabrication and the active perfusion of hydrogel constructs with multi-dimensional vasculature and controlled mechanical properties targeting soft tissues. Specifically, the initial part of the research...... nanotechnology-based paradigm for engineering vascularised liver tissue for transplantation”) and the Danish National Research Foundation and Villum Foundation’s Center for Intelligent Drug delivery and sensing Using microcontainers and Nanomechanics (Danish National Research Foundation (DNRF122)....

  20. Streptococcus anginosus infections: crossing tissue planes.

    Science.gov (United States)

    Sunwoo, Bernie Y; Miller, Wallace T

    2014-10-01

    Streptococcus anginosus has long been recognized to cause invasive pyogenic infections. This holds true for thoracic infections where S. anginosus has a propensity for abscess and empyema formation. Early diagnosis is important given the significant morbidity and mortality associated with thoracic S. anginosus infections. Yet, distinguishing thoracic S. anginosus clinically is difficult. We present three cases of thoracic S. anginosus that demonstrated radiographic extension across tissue planes, including the interlobar fissure, diaphragm, and chest wall. Few infectious etiologies are known to cross tissue planes. Accordingly, we propose S. anginosus be considered among the differential diagnosis of potential infectious etiologies causing radiographic extension across tissue planes.

  1. [Scanning electron microscopy of heat-damaged bone tissue].

    Science.gov (United States)

    Harsanyl, L

    1977-02-01

    Parts of diaphyses of bones were exposed to high temperature of 200-1300 degrees C. Damage to the bone tissue caused by the heat was investigated. The scanning electron microscopic picture seems to be characteristic of the temperature applied. When the bones heated to the high temperature of 700 degrees C characteristic changes appear on the periostal surface, higher temperatura on the other hand causes damage to the compact bone tissue and can be observed on the fracture-surface. Author stresses the importance of this technique in the legal medicine and anthropology.

  2. The influence of freezing and tissue porosity on the material properties of vegetable tissues

    Energy Technology Data Exchange (ETDEWEB)

    Ralfs, Julie D

    2002-07-01

    Tissue porosity and fluid flow have been shown to be important parameters affecting the mechanical and sensorial behaviour of edible plant tissues. The quantity of fluid and the manner with which it was released on compression of the plant tissue were also important regarding the sensory perception and a good indication of any structural damage resulting from freezing, for example. Potato, carrot and Chinese water chestnut were used to study the effects freezing has on model plant tissues. Mechanical and structural measurements of the plant tissue were correlated with sensory analysis. Conventional freezing was shown to cause severe structural damage predominantly in the form of cavities between or through cells, resulting in decreases in mechanical strength and stiffness, and samples that were perceived in the mouth as 'soft' and 'wet'. The location and size of the cavities formed from ice crystals, depended on the particular plant tissue being frozen, the processing it was subjected to prior to freezing, the size of the sample and the cooling regime employed to freeze the tissue. Cavitation in the tissue resulted in an increase in tissue porosity, which enabled fluid to flow more easily from the tissue on compression, thus affecting the mechanical properties and sensory perception. Freezing damage to plant tissues was shown to be reduced, and sometimes prevented, when active antifreeze proteins (AFPs) were introduced into the tissues by vacuum infiltration or transformation and the tissue was frozen at a suitable cooling rate. Theoretical modelling was applied to the fluid flow and porosity data to test the validity of the models and to subsequently predict the mechanical behaviour of potato from the structural properties of the tissue. (author)

  3. The influence of freezing and tissue porosity on the material properties of vegetable tissues

    International Nuclear Information System (INIS)

    Ralfs, Julie D.

    2002-01-01

    Tissue porosity and fluid flow have been shown to be important parameters affecting the mechanical and sensorial behaviour of edible plant tissues. The quantity of fluid and the manner with which it was released on compression of the plant tissue were also important regarding the sensory perception and a good indication of any structural damage resulting from freezing, for example. Potato, carrot and Chinese water chestnut were used to study the effects freezing has on model plant tissues. Mechanical and structural measurements of the plant tissue were correlated with sensory analysis. Conventional freezing was shown to cause severe structural damage predominantly in the form of cavities between or through cells, resulting in decreases in mechanical strength and stiffness, and samples that were perceived in the mouth as 'soft' and 'wet'. The location and size of the cavities formed from ice crystals, depended on the particular plant tissue being frozen, the processing it was subjected to prior to freezing, the size of the sample and the cooling regime employed to freeze the tissue. Cavitation in the tissue resulted in an increase in tissue porosity, which enabled fluid to flow more easily from the tissue on compression, thus affecting the mechanical properties and sensory perception. Freezing damage to plant tissues was shown to be reduced, and sometimes prevented, when active antifreeze proteins (AFPs) were introduced into the tissues by vacuum infiltration or transformation and the tissue was frozen at a suitable cooling rate. Theoretical modelling was applied to the fluid flow and porosity data to test the validity of the models and to subsequently predict the mechanical behaviour of potato from the structural properties of the tissue. (author)

  4. Tissue disposition of bifenthrin in the rat

    Data.gov (United States)

    U.S. Environmental Protection Agency — Tissue disposition of bifenthrin in the rat and oral and intravenous administration. This dataset is associated with the following publication: Hughes , M., D. Ross...

  5. SEM investigation of heart tissue samples

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, R; Amoroso, M [Physics Department, University of the West Indies, St. Augustine, Trinidad and Tobago, West Indies (Trinidad and Tobago)

    2010-07-01

    We used the scanning electron microscope to examine the cardiac tissue of a cow (Bos taurus), a pig (Sus scrofa), and a human (Homo sapiens). 1mm{sup 3} blocks of left ventricular tissue were prepared for SEM scanning by fixing in 96% ethanol followed by critical point drying (cryofixation), then sputter-coating with gold. The typical ridged structure of the myofibrils was observed for all the species. In addition crystal like structures were found in one of the samples of the heart tissue of the pig. These structures were investigated further using an EDVAC x-ray analysis attachment to the SEM. Elemental x-ray analysis showed highest peaks occurred for gold, followed by carbon, oxygen, magnesium and potassium. As the samples were coated with gold for conductivity, this highest peak is expected. Much lower peaks at carbon, oxygen, magnesium and potassium suggest that a cystallized salt such as a carbonate was present in the tissue before sacrifice.

  6. Differences in breast tissue oxygenation following radiotherapy

    International Nuclear Information System (INIS)

    Dornfeld, Ken; Gessert, Charles E.; Renier, Colleen M.; McNaney, David D.; Urias, Rodolfo E.; Knowles, Denise M.; Beauduy, Jean L.; Widell, Sherry L.; McDonald, Bonita L.

    2011-01-01

    Tissue perfusion and oxygenation changes following radiotherapy may result from and/or contribute to the toxicity of treatment. Breast tissue oxygenation levels were determined in the treated and non-treated breast 1 year after radiotherapy for breast conserving treatment. Transcutaneous oxygenation varied between subjects in both treated and non-treated breast. Subjects without diabetes mellitus (n = 16) had an average oxygenation level of 64.8 ± 19.9 mmHg in the irradiated breast and an average of 72.3 ± 18.1 mmHg (p = 0.018) at the corresponding location in the control breast. Patients with diabetes (n = 4) showed a different oxygenation pattern, with lower oxygenation levels in control tissue and no decrease in the irradiated breast. This study suggests oxygenation levels in normal tissues vary between patients and may respond differently after radiotherapy.

  7. Imaging the hard/soft tissue interface.

    Science.gov (United States)

    Bannerman, Alistair; Paxton, Jennifer Z; Grover, Liam M

    2014-03-01

    Interfaces between different tissues play an essential role in the biomechanics of native tissues and their recapitulation is now recognized as critical to function. As a consequence, imaging the hard/soft tissue interface has become increasingly important in the area of tissue engineering. Particularly as several biotechnology based products have made it onto the market or are close to human trials and an understanding of their function and development is essential. A range of imaging modalities have been developed that allow a wealth of information on the morphological and physical properties of samples to be obtained non-destructively in vivo or via destructive means. This review summarizes the use of a selection of imaging modalities on interfaces to date considering the strengths and weaknesses of each. We will also consider techniques which have not yet been utilized to their full potential or are likely to play a role in future work in the area.

  8. White adipose tissue coloring by intermittent fasting.

    Science.gov (United States)

    Kivelä, Riikka; Alitalo, Kari

    2017-11-01

    Intermittent fasting (IF) has been shown to promote metabolic health in several organisms. Two recent papers show that IF induces white adipose tissue beiging and increases thermogenesis, which improves metabolic health in mice.

  9. Drugs Approved for Soft Tissue Sarcoma

    Science.gov (United States)

    This page lists cancer drugs approved by the Food and Drug Administration (FDA) for soft tissue sarcoma. The list includes generic names and brand names. The drug names link to NCI's Cancer Drug Information summaries.

  10. SEM investigation of heart tissue samples

    International Nuclear Information System (INIS)

    Saunders, R; Amoroso, M

    2010-01-01

    We used the scanning electron microscope to examine the cardiac tissue of a cow (Bos taurus), a pig (Sus scrofa), and a human (Homo sapiens). 1mm 3 blocks of left ventricular tissue were prepared for SEM scanning by fixing in 96% ethanol followed by critical point drying (cryofixation), then sputter-coating with gold. The typical ridged structure of the myofibrils was observed for all the species. In addition crystal like structures were found in one of the samples of the heart tissue of the pig. These structures were investigated further using an EDVAC x-ray analysis attachment to the SEM. Elemental x-ray analysis showed highest peaks occurred for gold, followed by carbon, oxygen, magnesium and potassium. As the samples were coated with gold for conductivity, this highest peak is expected. Much lower peaks at carbon, oxygen, magnesium and potassium suggest that a cystallized salt such as a carbonate was present in the tissue before sacrifice.

  11. NCI’s Cooperative Human Tissue Network

    Science.gov (United States)

    Quality biospecimens are a foundational resource for cancer research. One of NCI’s longest running biospecimen programs is the Cooperative Human Tissue Network, a resource mainly for basic discovery and early translational research.

  12. High-dose erythropoietin for tissue protection

    DEFF Research Database (Denmark)

    Lund, Anton; Lundby, Carsten; Olsen, Niels Vidiendal

    2014-01-01

    BACKGROUND: The discovery of potential anti-apoptotic and cytoprotective effects of recombinant human erythropoietin (rHuEPO) has led to clinical trials investigating the use of high-dose, short-term rHuEPO therapy for tissue protection in conditions such as stroke and myocardial infarction....... Experimental studies have been favourable, but the clinical efficacy has yet to be validated. MATERIALS AND METHODS: We have reviewed clinical studies regarding the use of high-dose, short-term rHuEPO therapy for tissue protection in humans with the purpose to detail the safety and efficacy of r...... no effect of rHuEPO therapy on measures of tissue protection. Five trials including 1025 patients reported safety concerns in the form of increased mortality or adverse event rates. No studies reported reduced mortality. CONCLUSIONS: Evidence is sparse to support a tissue-protective benefit of r...

  13. Vascularization of soft tissue engineering constructs

    DEFF Research Database (Denmark)

    Pimentel Carletto, Rodrigo

    nanotechnology-based paradigm for engineering vascularised liver tissue for transplantation”) and the Danish National Research Foundation and Villum Foundation’s Center for Intelligent Drug delivery and sensing Using microcontainers and Nanomechanics (Danish National Research Foundation (DNRF122).......Vascularization is recognized to be the biggest challenge for the fabrication of tissues and finally, organs in vitro. So far, several fabrication techniques have been proposed to create a perfusable vasculature within hydrogels, however, the vascularization and perfusion of hydrogels...... with mechanical properties in the range of soft tissues has not been fully achieved. My project focused on the fabrication and the active perfusion of hydrogel constructs with multi-dimensional vasculature and controlled mechanical properties targeting soft tissues. Specifically, the initial part of the research...

  14. Synthetic aperture tissue and flow ultrasound imaging

    DEFF Research Database (Denmark)

    Nikolov, Svetoslav

    imaging applied to medical ultrasound. It is divided into two major parts: tissue and blood flow imaging. Tissue imaging using synthetic aperture algorithms has been investigated for about two decades, but has not been implemented in medical scanners yet. Among the other reasons, the conventional scanning...... and beamformation methods are adequate for the imaging modalities in clinical use - the B-mode imaging of tissue structures, and the color mapping of blood flow. The acquisition time, however, is too long, and these methods fail to perform real-time three-dimensional scans. The synthetic transmit aperture......, on the other hand, can create a Bmode image with as little as 2 emissions, thus significantly speeding-up the scan procedure. The first part of the dissertation describes the synthetic aperture tissue imaging. It starts with an overview of the efforts previously made by other research groups. A classification...

  15. Developing 3D microstructures for tissue engineering

    DEFF Research Database (Denmark)

    Mohanty, Soumyaranjan

    casting process to generate various large scale tissue engineering constructs with single pore geometry with the desired mechanical stiffness and porosity. In addition, a new technique was developed to fa bricate dual-pore scaffolds for various tissue-engineering applications where 3D printing...... materials have been developed and tested for enhancing the differentiation of hiPSC-derived hepatocytes and fabricating biodegradable scaffolds for in-vivo tissue engineering applications. Along with various scaffolds fabrication methods we finally presented an optimized study of hepatic differentiation...... of hiPSC-derived DE cells cultured for 25 days in a 3D perfusion bioreactor system with an array of 16 small-scale tissue-bioreactors with integrated dual-pore pore scaffolds and flow rates. Hepatic differentiation and functionality of hiPSC-derived hepatocytes were successfully assessed and compared...

  16. Skin and soft-tissue infec tions

    African Journals Online (AJOL)

    2010-06-01

    Jun 1, 2010 ... Patients with skin and soft-tissue infections (SSTIs) often initially present to family physicians. ..... Nosocomial infections are often caused by MRSA or mixed .... site infections are good hand hygiene, good surgical technique.

  17. Construction of retroviral recombinant containing human tissue ...

    African Journals Online (AJOL)

    USER

    2010-03-29

    Mar 29, 2010 ... Recombinant retroviral vector containing human tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) gene was ..... heavy metal ions, the protein could be express in an .... involves adhesion, degradation and movement. To.

  18. DOPA, norepinephrine, and dopamine in rat tissues

    DEFF Research Database (Denmark)

    Eldrup, E; Richter, Erik; Christensen, N J

    1989-01-01

    We studied the effect of unilateral sympathectomy on rat quadriceps and gastrocnemius muscle concentrations of endogenous dihydroxyphenylalanine (DOPA), dopamine (DA), and norepinephrine (NE) and assessed the relationships between these catecholamines in several rat tissues. Catecholamines were...

  19. Adenovirus 36 DNA in human adipose tissue.

    Science.gov (United States)

    Ponterio, E; Cangemi, R; Mariani, S; Casella, G; De Cesare, A; Trovato, F M; Garozzo, A; Gnessi, L

    2015-12-01

    Recent studies have suggested a possible correlation between obesity and adenovirus 36 (Adv36) infection in humans. As information on adenoviral DNA presence in human adipose tissue are limited, we evaluated the presence of Adv36 DNA in adipose tissue of 21 adult overweight or obese patients. Total DNA was extracted from adipose tissue biopsies. Virus detection was performed using PCR protocols with primers against specific Adv36 fiber protein and the viral oncogenic E4orf1 protein nucleotide sequences. Sequences were aligned with the NCBI database and phylogenetic analyses were carried out with MEGA6 software. Adv36 DNA was found in four samples (19%). This study indicates that some individuals carry Adv36 in the visceral adipose tissue. Further studies are needed to determine the specific effect of Adv36 infection on adipocytes, the prevalence of Adv36 infection and its relationship with obesity in the perspective of developing a vaccine that could potentially prevent or mitigate infection.

  20. Processing laboratory of radio sterilized biological tissues

    International Nuclear Information System (INIS)

    Aguirre H, Paulina; Zarate S, Herman; Silva R, Samy; Hitschfeld, Mario

    2005-01-01

    The nuclear development applications have also reached those areas related to health. The risk of getting contagious illnesses through applying biological tissues has been one of the paramount worries to be solved since infectious illnesses might be provoked by virus, fungis or bacterias coming from donors or whether they have been introduced by means of intermediate stages before the use of these tissues. Therefore it has been concluded that the tissue allografts must be sterilized. The sterilization of medical products has been one of the main applications of the ionizing radiations and that it is why the International Organization of Atomic Energy began in the 70s promoting works related to the biological tissue sterilization and pharmaceutical products. The development of different tissue preservation methods has made possible the creation of tissue banks in different countries, to deal with long-term preservation. In our country, a project was launched in 1998, 'Establishment of a Tissue Bank in Latino america', this project was supported by the OIEA through the project INT/ 6/ 049, and was the starting of the actual Processing Laboratory of Radioesterilized Biological Tissues (LPTR), leaded by the Chilean Nuclear Energy Commission (CCHEN). This first organization is part of a number of entities compounding the Tissue Bank in Chile, organizations such as the Transplantation Promotion Corporation hospitals and the LPTR. The working system is carried out by means of the interaction between the hospitals and the laboratory. The medical professionals perform the procuring of tissues in the hospitals, then send them to the LPTR where they are processed and sterilized with ionizing radiation. The cycle ends up with the tissues return released to the hospitals, where they are used, and then the result information is sent to the LPTR as a form of feedback. Up to now, human skin has been processed (64 donors), amniotic membranes (35 donors) and pig skin (175 portions

  1. Deep soft tissue leiomyoma of the thigh

    International Nuclear Information System (INIS)

    Watson, G.M.T.; Saifuddin, A.; Sandison, A.

    1999-01-01

    A case of ossified leiomyoma of the deep soft tissues of the left thigh is presented. The radiographic appearance suggested a low-grade chondrosarcoma. MRI of the lesion showed signal characteristics similar to muscle on both T1- and T2-weighted spin echo sequences with linear areas of high signal intensity on T1-weighted images consistent with medullary fat in metaplastic bone. Histopathological examination of the resected specimen revealed a benign ossified soft tissue leiomyoma. (orig.)

  2. CO2 laser milling of hard tissue

    Science.gov (United States)

    Werner, Martin; Ivanenko, Mikhail; Harbecke, Daniela; Klasing, Manfred; Steigerwald, Hendrik; Hering, Peter

    2007-02-01

    Drilling of bone and tooth tissue belongs to recurrent medical procedures (screw- and pin-bores, bores for implant inserting, trepanation etc.). Small round bores can be in general quickly produced with mechanical drills. Problems arise however by angled drilling, by the necessity to fulfill the drilling without damaging of sensitive soft tissue beneath the bone, or by the attempt to mill precisely noncircular small cavities. We present investigations on laser hard tissue "milling", which can be advantageous for solving these problems. The "milling" is done with a CO2 laser (10.6 μm) with pulse duration of 50 - 100 μs, combined with a PC-controlled galvanic beam scanner and with a fine water-spray, which helps to avoid thermal side-effects. The damaging of underlying soft tissue can be prevented through control of the optical or acoustical ablation signal. The ablation of hard tissue is accompanied with a strong glowing, which is absent during the laser beam action on soft tissue. The acoustic signals from the diverse tissue types exhibit distinct differences in the spectral composition. Also computer image analysis could be a useful tool to control the operation. Laser "milling" of noncircular cavities with 1 - 4 mm width and about 10 mm depth is particularly interesting for dental implantology. In ex-vivo investigations we found conditions for fast laser "milling" of the cavities without thermal damage and with minimal tapering. It included exploration of different filling patterns (concentric rings, crosshatch, parallel lines and their combinations), definition of maximal pulse duration, repetition rate and laser power, optimal position of the spray. The optimized results give evidences for the applicability of the CO2 laser for biologically tolerable "milling" of deep cavities in the hard tissue.

  3. Introduction to regenerative medicine and tissue engineering.

    Science.gov (United States)

    Stoltz, J-F; Decot, V; Huseltein, C; He, X; Zhang, L; Magdalou, J; Li, Y P; Menu, P; Li, N; Wang, Y Y; de Isla, N; Bensoussan, D

    2012-01-01

    Human tissues don't regenerate spontaneously, explaining why regenerative medicine and cell therapy represent a promising alternative treatment (autologous cells or stem cells of different origins). The principle is simple: cells are collected, expanded and introduced with or without modification into injured tissues or organs. Among middle-term therapeutic applications, cartilage defects, bone repair, cardiac insufficiency, burns, liver or bladder, neurodegenerative disorders could be considered.

  4. European quality system for tissue banking.

    Science.gov (United States)

    Manyalich, M; Navarro, A; Koller, J; Loty, B; de Guerra, A; Cornu, O; Vabels, G; Fornasari, P M; Costa, A N; Siska, I; Hirn, M; Franz, N; Miranda, B; Kaminski, A; Uhrynowska, I; Van Baare, J; Trias, E; Fernández, C; de By, T; Poniatowski, S; Carbonell, R

    2009-01-01

    The aims of this project were to analyze the factors that influence quality and safety of tissues for transplantation and to develop the method to ensure standards of quality and safety in relation to tissue banking as demanded by European Directive 2004/23/EC and its technical annexes. It is organized in 4 Working Groups, the objectives of each one being focused in a specific area. The Guide of Recommendations for Tissue Banking is structured into 4 parts: (1) quality systems that apply to tissue banking and general quality system requirements, (2) regulatory framework in Europe, (3) standards available, and (4) recommendations of the fundamental quality and safety keypoints. This Working Group handled design of a multinational musculoskeletal tissue registry prototype. This Working Group handled design and validation of a specialized training model structured into online and face-to-face courses. The model was improved with suggestions from students, and 100% certification was obtained. The Guide for Auditing Tissue Establishments provides guidance for auditors, a self-assessment questionnaire, and an audit report form. The effectiveness and sustainability of the outputs were assessed. Both guides are useful for experienced tissue establishments and auditors and also for professionals that are starting in the field. The registry prototype proves it is possible to exchange tissues between establishments throughout Europe. The training model has been effective in educating staff and means having professionals with excellent expertise. Member states could adapt/adopt it. The guides should be updated periodically and perhaps a European organization should take responsibility for this and even create a body of auditors.

  5. Tissue Engineering Strategies in Ligament Regeneration

    OpenAIRE

    Yilgor, Caglar; Yilgor Huri, Pinar; Huri, Gazi

    2011-01-01

    Ligaments are dense fibrous connective tissues that connect bones to other bones and their injuries are frequently encountered in the clinic. The current clinical approaches in ligament repair and regeneration are limited to autografts, as the gold standard, and allografts. Both of these techniques have their own drawbacks that limit the success in clinical setting; therefore, new strategies are being developed in order to be able to solve the current problems of ligament grafting. Tissue eng...

  6. Pediatric rhabdomyosarcomas and nonrhabdomyosarcoma soft tissue sarcoma

    OpenAIRE

    Agarwala Sandeep

    2006-01-01

    Tumors arising from the soft tissues are uncommon in children, accounting for about 6% of all childhood malignancies. More than half (53%) of these originate from the striated muscles and are called rhabdomyosarcomas (RMS) the remaining are nonrhabdomyosarcoma soft tissue sarcomas (NRSTS). Almost two-thirds of RMS cases are diagnosed in children < 6 years of age. They can arise at varied locations like the head and neck region, genitourinary tract, extremities, trunk and retrope...

  7. Pediatric brain tumors of neuroepithelial tissue

    International Nuclear Information System (INIS)

    Papanagiotou, P.; Politi, M.; Bergmann, M.; Pekrun, A.; Juergens, K.U.

    2014-01-01

    Tumors of neuroepithelial tissue represent the largest group of pediatric brain tumors by far and has therefore been divided into several discrete tumor subtypes each corresponding to a specific component of the neuropil. The neuropil contains several subtypes of glial cells, including astrocytes, oligodendrocytes, ependymal cells and modified ependymal cells that form the choroid plexus. This review discusses the imaging aspects of the most common pediatric tumors of neuroepithelial tissue. (orig.) [de

  8. Dermal fillers for facial soft tissue augmentation.

    Science.gov (United States)

    Dastoor, Sarosh F; Misch, Carl E; Wang, Hom-Lay

    2007-01-01

    Nowadays, patients are demanding not only enhancement to their dental (micro) esthetics, but also their overall facial (macro) esthetics. Soft tissue augmentation via dermal filling agents may be used to correct facial defects such as wrinkles caused by age, gravity, and trauma; thin lips; asymmetrical facial appearances; buccal fold depressions; and others. This article will review the pathogenesis of facial wrinkles, history, techniques, materials, complications, and clinical controversies regarding dermal fillers for soft tissue augmentation.

  9. Local tissue distribution of fissile nuclides

    International Nuclear Information System (INIS)

    Smith, J.M.

    1981-01-01

    Conventional tissue-section autoradiography of alpha-emitting actinide elements may require prohibitively long exposure times. Neutron-induced or fission-track autoradiography can be used for fissile nuclides such as 233 U, 235 U, and 239 Pu to circumvent this difficulty. The detection limit for these nuclides is about 4 x 10 -13 (weight fraction). This paper describes a specific technique for determining their microdistribution with histologically stained tissue sections

  10. Actinomyces associated with persistent vaginal granulation tissue.

    OpenAIRE

    Wai, Clifford Y; Nihira, Mikio A; Drewes, Peter G; Chang, Joe S; Siddiqui, Momin T; Hemsell, David L

    2005-01-01

    BACKGROUND: We report a case of symptomatic actinomycosis associated with vaginal suture erosion and granulation tissue refractory to conservative management, in an outpatient setting. CASE: Three months after total vaginal hysterectomy and uterosacral ligament vaginal vault suspension, a woman complained of painless, intermittent vaginal discharge and spotting. Despite cauterization of granulation tissue, vaginal spotting persisted for another month. On re-examination, braided polyester sutu...

  11. Tissue Engineering: Current Strategies and Future Directions

    OpenAIRE

    Olson, Jennifer L.; Atala, Anthony; Yoo, James J.

    2011-01-01

    Novel therapies resulting from regenerative medicine and tissue engineering technology may offer new hope for patients with injuries, end-stage organ failure, or other clinical issues. Currently, patients with diseased and injured organs are often treated with transplanted organs. However, there is a shortage of donor organs that is worsening yearly as the population ages and as the number of new cases of organ failure increases. Scientists in the field of regenerative medicine and tissue eng...

  12. Direct plasma interaction with living tissue

    Science.gov (United States)

    Fridman, Gregory

    For some time, plasma has been used in medicine to cauterize or cut tissue using heat and mechanical energy. In the recent decade, some researchers around the world have started to investigate how gas jets that pass through thermal plasma can be employed in medicine. This thesis presents the first investigation of biomedical uses of non-thermal plasma discharge which comes in direct contact with living tissue. It is demonstrated that the direct application of non-thermal plasma in air can cause rapid deactivation of bacteria on surfaces of tissues without causing any visible tissue damage. Medical need for such a device is discussed. Construction and operation of various types of non-thermal plasma power supplies and many types of treatment electrodes are presented as well. Application of this plasma to living organisms is shown to be safe from both the electrical perspective and from the biological perspective. Biological safety is revealed through a series of differential skin toxicity trials on human cadaver tissue, live hairless mouse skin tissue, live pig skin tissue, and finally in an open wound model on pigs. Direct non-thermal plasma in air is shown to deactivate bacteria about 100 times faster than indirect application using jets. A series of experiments reveal that this effectiveness is due to the ability of direct discharge to bring charges to tissue surfaces. It is demonstrated that neither ultraviolet (UV) radiation nor neutral active species such as hydroxyl radicals or ozone produced in plasma are responsible for the main effect on bacteria. Although much additional work remains on establishing detailed mechanism by which charges from plasma achieve this effect, the work carried out in this thesis clearly demonstrates that direct application of non-thermal plasma in air can be a very useful tool in medicine.

  13. Laser tissue effects with regard to otorhinolaryngology

    International Nuclear Information System (INIS)

    Lippert, B.M.; Werner, J.A.; Rudert, H.

    1994-01-01

    The multitude of medical laser systems with different wavelengths and technical appliances implicates the necessity of fundamental knowledge about the effects of laser beams on living tissue. This is necessary to allow sufficient and therefore successful results for the patient. In this paper tissue effects of the mostly used lasers in otorhinolaryngology, CO-2 laser and Nd:YAG laser will be presented. Influence on blood and lymphatic vessels, wound healing and several CO-2 laser parameters will be discussed. (author)

  14. Introduction to tissue engineering applications and challenges

    CERN Document Server

    Birla, Ravi

    2014-01-01

    Covering a progressive medical field, Tissue Engineering describes the innovative process of regenerating human cells to restore or establish normal function in defective organs. As pioneering individuals look ahead to the possibility of generating entire organ systems, students may turn to this textbook for a comprehensive understanding and preparation for the future of regenerative medicine. This book explains chemical stimulations, the bioengineering of specific organs, and treatment plans for chronic diseases. It is a must-read for tissue engineering students and practitioners.

  15. The volume of fluid injected into the tissue expander and the tissue expansion

    Directory of Open Access Journals (Sweden)

    Mahmood Omranifard

    2014-01-01

    Full Text Available Background: Replacement of the lost tissue is the major concerns of the plastic surgeons. Expanded area should be coherent with the surrounding tissue. Tissue expansion technique is the reforming methods the skin tissue scarcities. Several methods for tissue expansion are available; including usage of silicon balloon and injecting fluid into the tissue expander. Materials and Methods: In a clinical trial study, 35 patients, with burn scars, in the face, skull and neck area were studied. We provided a tissue expander device with capacities of 125, 250 and 350cc. Fluid was injected inside the device, 3 consecutive weeks with 1-week interval. After 3 months the device was set out and the tissue expansion was measured using a transparent board and the results were analyzed. Multiple regression was done by SPSS 20 to analyze the data. Results: Regression model showed Skin expansion was positively correlated with the volume of the injected fluid. For each centimeter square of skin expansion, about 6-8 ml of fluid must be injected. Conclusion: Correction of skin defects resulting from burning scar is possible using tissue expanders. The tissue expansion is correlated with the amount of the injected fluid.

  16. Bioactive polymeric scaffolds for tissue engineering

    Directory of Open Access Journals (Sweden)

    Scott Stratton

    2016-12-01

    Full Text Available A variety of engineered scaffolds have been created for tissue engineering using polymers, ceramics and their composites. Biomimicry has been adopted for majority of the three-dimensional (3D scaffold design both in terms of physicochemical properties, as well as bioactivity for superior tissue regeneration. Scaffolds fabricated via salt leaching, particle sintering, hydrogels and lithography have been successful in promoting cell growth in vitro and tissue regeneration in vivo. Scaffold systems derived from decellularization of whole organs or tissues has been popular due to their assured biocompatibility and bioactivity. Traditional scaffold fabrication techniques often failed to create intricate structures with greater resolution, not reproducible and involved multiple steps. The 3D printing technology overcome several limitations of the traditional techniques and made it easier to adopt several thermoplastics and hydrogels to create micro-nanostructured scaffolds and devices for tissue engineering and drug delivery. This review highlights scaffold fabrication methodologies with a focus on optimizing scaffold performance through the matrix pores, bioactivity and degradation rate to enable tissue regeneration. Review highlights few examples of bioactive scaffold mediated nerve, muscle, tendon/ligament and bone regeneration. Regardless of the efforts required for optimization, a shift in 3D scaffold uses from the laboratory into everyday life is expected in the near future as some of the methods discussed in this review become more streamlined.

  17. The materials used in bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Tereshchenko, V. P., E-mail: tervp@ngs.ru; Kirilova, I. A.; Sadovoy, M. A.; Larionov, P. M. [Novosibirsk Research Institute of Traumatology and Orthopedics n.a. Ya.L. Tsivyan, Novosibirsk (Russian Federation)

    2015-11-17

    Bone tissue engineering looking for an alternative solution to the problem of skeletal injuries. The method is based on the creation of tissue engineered bone tissue equivalent with stem cells, osteogenic factors, and scaffolds - the carriers of these cells. For production of tissue engineered bone equivalent is advisable to create scaffolds similar in composition to natural extracellular matrix of the bone. This will provide optimal conditions for the cells, and produce favorable physico-mechanical properties of the final construction. This review article gives an analysis of the most promising materials for the manufacture of cell scaffolds. Biodegradable synthetic polymers are the basis for the scaffold, but it alone cannot provide adequate physical and mechanical properties of the construction, and favorable conditions for the cells. Addition of natural polymers improves the strength characteristics and bioactivity of constructions. Of the inorganic compounds, to create cell scaffolds the most widely used calcium phosphates, which give the structure adequate stiffness and significantly increase its osteoinductive capacity. Signaling molecules do not affect the physico-mechanical properties of the scaffold, but beneficial effect is on the processes of adhesion, proliferation and differentiation of cells. Biodegradation of the materials will help to fulfill the main task of bone tissue engineering - the ability to replace synthetic construct by natural tissues that will restore the original anatomical integrity of the bone.

  18. Microgravity Stress: Bone and Connective Tissue.

    Science.gov (United States)

    Bloomfield, Susan A; Martinez, Daniel A; Boudreaux, Ramon D; Mantri, Anita V

    2016-03-15

    The major alterations in bone and the dense connective tissues in humans and animals exposed to microgravity illustrate the dependency of these tissues' function on normal gravitational loading. Whether these alterations depend solely on the reduced mechanical loading of zero g or are compounded by fluid shifts, altered tissue blood flow, radiation exposure, and altered nutritional status is not yet well defined. Changes in the dense connective tissues and intervertebral disks are generally smaller in magnitude but occur more rapidly than those in mineralized bone with transitions to 0 g and during recovery once back to the loading provided by 1 g conditions. However, joint injuries are projected to occur much more often than the more catastrophic bone fracture during exploration class missions, so protecting the integrity of both tissues is important. This review focuses on the research performed over the last 20 years in humans and animals exposed to actual spaceflight, as well as on knowledge gained from pertinent ground-based models such as bed rest in humans and hindlimb unloading in rodents. Significant progress has been made in our understanding of the mechanisms for alterations in bone and connective tissues with exposure to microgravity, but intriguing questions remain to be solved, particularly with reference to biomedical risks associated with prolonged exploration missions. Copyright © 2016 John Wiley & Sons, Inc.

  19. Sterilization of biological tissues with ionizing radiation

    International Nuclear Information System (INIS)

    Reyes F, M.L.; Martinez P, M.E.; Luna Z, D.

    1997-01-01

    On June 1994, the National Institute of Nuclear Research (ININ) and the South Central Hospital for High Specialty of PEMEX (HCSAE) began a joint work with the finality to obtain radio sterilized amniotic membranes for to be used as cover (biological bandage) in burnt patients. Subsequently the Chemistry Faculty of UNAM and the National Institute of Cardiology began to collaborate this last with interest on cardiac valves for graft. Starting from 1997, the International Atomic Energy Agency (IAEA) supports this project (MEX/7/008) whose main objective is to set up the basis to establish in Mexico a Radio sterilized Tissue Bank (amniotic membranes, skin, bones, tendons, cardiac valves, etc.) to be used with therapeutic purposes (grafts). The IAEA support has consisted in the equipment acquisition which is fundamental for the Tissue Bank performance such as an experimental irradiator, laminar flow bell, lyophilizer, vacuum sealer and special knives for tissues. Also visits to Mexico of experts have been authorized with the aim of advising to the personnel which participate in the project and scientific visits of this personnel to another tissue banks (Sri Lanka and Argentine). The establishment in Mexico of a Tissue bank will be a great benefit because it will have availability of distinct tissues for grafts and it will reduce the synthetic materials importation which is very expensive. (Author)

  20. 3D bioprinting of tissues and organs.

    Science.gov (United States)

    Murphy, Sean V; Atala, Anthony

    2014-08-01

    Additive manufacturing, otherwise known as three-dimensional (3D) printing, is driving major innovations in many areas, such as engineering, manufacturing, art, education and medicine. Recent advances have enabled 3D printing of biocompatible materials, cells and supporting components into complex 3D functional living tissues. 3D bioprinting is being applied to regenerative medicine to address the need for tissues and organs suitable for transplantation. Compared with non-biological printing, 3D bioprinting involves additional complexities, such as the choice of materials, cell types, growth and differentiation factors, and technical challenges related to the sensitivities of living cells and the construction of tissues. Addressing these complexities requires the integration of technologies from the fields of engineering, biomaterials science, cell biology, physics and medicine. 3D bioprinting has already been used for the generation and transplantation of several tissues, including multilayered skin, bone, vascular grafts, tracheal splints, heart tissue and cartilaginous structures. Other applications include developing high-throughput 3D-bioprinted tissue models for research, drug discovery and toxicology.

  1. From DNA lesions to tissue malfunction

    International Nuclear Information System (INIS)

    Denekamp, J.

    1989-01-01

    After large doses of radiation, tissues fail to function when the proliferating cells lose their clonogenic ability. This results from unrepaired or misrepaired double strand breaks in the DNA. The lesions are inflicted immediately but there is a variable latent period before tissue damage is expressed. This ranges from a few days in intestine, to weeks in skin, and to months or years in deep visceral tissues, e.g. heart, lung, kidney, spinal cord. The latency relates to the proliferation kinetics of each tissue component. Doses of 10-30 Gy do not cause serious functional defects in differentiated cells, but they prevent successful mitosis in proliferating cells. Thus each tissue continues to function until its differentiated cells are lost by normal wear and tear processes. After a time which relates to the natural lifespan of the differentiated cells, failure to provide replacement cells from the proliferating compartment becomes important and the tissue shows atrophy and eventually a functional deficit. If the radiation exposure is divided into a series of smaller exposures or is given at a low dose-rate, the biochemical repair of DNA is more effective and less damage is observed. After high LET ionizing radiation, e.g. neutrons or α particles, the response is almost linear and is not affected by doserate or fractionation. (author)

  2. Stem cells in bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Jeong Min [Department of Preventive and Social Dentistry and Institute of Oral Biology, College of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Kim, Byung-Chul; Park, Jae-Hong; Kwon, Il Keun; Hwang, Yu-Shik [Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, College of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Mantalaris, Anathathios, E-mail: yshwang@khu.ac.k [Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom)

    2010-12-15

    Bone tissue engineering has been one of the most promising areas of research, providing a potential clinical application to cure bone defects. Recently, various stem cells including embryonic stem cells (ESCs), bone marrow-derived mesenchymal stem cells (BM-MSCs), umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs), adipose tissue-derived stem cells (ADSCs), muscle-derived stem cells (MDSCs) and dental pulp stem cells (DPSCs) have received extensive attention in the field of bone tissue engineering due to their distinct biological capability to differentiate into osteogenic lineages. The application of these stem cells to bone tissue engineering requires inducing in vitro differentiation of these cells into bone forming cells, osteoblasts. For this purpose, efficient in vitro differentiation towards osteogenic lineage requires the development of well-defined and proficient protocols. This would reduce the likelihood of spontaneous differentiation into divergent lineages and increase the available cell source for application to bone tissue engineering therapies. This review provides a critical examination of the various experimental strategies that could be used to direct the differentiation of ESC, BM-MSC, UCB-MSC, ADSC, MDSC and DPSC towards osteogenic lineages and their potential applications in tissue engineering, particularly in the regeneration of bone. (topical review)

  3. Traction force microscopy of engineered cardiac tissues.

    Science.gov (United States)

    Pasqualini, Francesco Silvio; Agarwal, Ashutosh; O'Connor, Blakely Bussie; Liu, Qihan; Sheehy, Sean P; Parker, Kevin Kit

    2018-01-01

    Cardiac tissue development and pathology have been shown to depend sensitively on microenvironmental mechanical factors, such as extracellular matrix stiffness, in both in vivo and in vitro systems. We present a novel quantitative approach to assess cardiac structure and function by extending the classical traction force microscopy technique to tissue-level preparations. Using this system, we investigated the relationship between contractile proficiency and metabolism in neonate rat ventricular myocytes (NRVM) cultured on gels with stiffness mimicking soft immature (1 kPa), normal healthy (13 kPa), and stiff diseased (90 kPa) cardiac microenvironments. We found that tissues engineered on the softest gels generated the least amount of stress and had the smallest work output. Conversely, cardiomyocytes in tissues engineered on healthy- and disease-mimicking gels generated significantly higher stresses, with the maximal contractile work measured in NRVM engineered on gels of normal stiffness. Interestingly, although tissues on soft gels exhibited poor stress generation and work production, their basal metabolic respiration rate was significantly more elevated than in other groups, suggesting a highly ineffective coupling between energy production and contractile work output. Our novel platform can thus be utilized to quantitatively assess the mechanotransduction pathways that initiate tissue-level structural and functional remodeling in response to substrate stiffness.

  4. Progress in the processing of radioesterilized tissue

    International Nuclear Information System (INIS)

    Zarate S, H; Espinoza B, J; Ribbeck N, J; Vargas Q, M; Gutierrez D, K

    2003-01-01

    Since 1996, the Chilean Nuclear Energy Commission has been carrying out work to implement the first Radiosterilized Tissue Processing Laboratory (RTPL) in Chile, in order to introduce the use of sterilized biological tissue for clinical application. The International Atomic Energy Agency (IAEA) has provided collaboration and technical assistance for this work. The processing of biological tissues has been done in conjunction with physicians from different state hospital centers, mostly in the Metropolitan Region. Among the tissues primarily processed are allografts such as frozen human skin at - 80 o C, freeze-dried human bone and amniotic membrane. We have also been working with xenograft developments such as freeze-dried pig skin and demineralized ground cow bone. All these tissues are sterilized by means of gamma radiation, in order to obtain a sterility assurance level (SAL) of 10 -6 . This laboratory has already completed various stages, from the beginning when it was only just an idea up to the production stage where a large quantity of processed tissues have been delivered to physicians of different specialties, resulting in a contribution to medical science as well as to the treatment quality of a great many patients. The preliminary results and the opinions of those physicians who have used the processed products from our laboratory have encouraged us to continue developing new products, thus enlarging the scope of application (author)

  5. Stem cells in bone tissue engineering

    International Nuclear Information System (INIS)

    Seong, Jeong Min; Kim, Byung-Chul; Park, Jae-Hong; Kwon, Il Keun; Hwang, Yu-Shik; Mantalaris, Anathathios

    2010-01-01

    Bone tissue engineering has been one of the most promising areas of research, providing a potential clinical application to cure bone defects. Recently, various stem cells including embryonic stem cells (ESCs), bone marrow-derived mesenchymal stem cells (BM-MSCs), umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs), adipose tissue-derived stem cells (ADSCs), muscle-derived stem cells (MDSCs) and dental pulp stem cells (DPSCs) have received extensive attention in the field of bone tissue engineering due to their distinct biological capability to differentiate into osteogenic lineages. The application of these stem cells to bone tissue engineering requires inducing in vitro differentiation of these cells into bone forming cells, osteoblasts. For this purpose, efficient in vitro differentiation towards osteogenic lineage requires the development of well-defined and proficient protocols. This would reduce the likelihood of spontaneous differentiation into divergent lineages and increase the available cell source for application to bone tissue engineering therapies. This review provides a critical examination of the various experimental strategies that could be used to direct the differentiation of ESC, BM-MSC, UCB-MSC, ADSC, MDSC and DPSC towards osteogenic lineages and their potential applications in tissue engineering, particularly in the regeneration of bone. (topical review)

  6. Articular cartilage: from formation to tissue engineering.

    Science.gov (United States)

    Camarero-Espinosa, Sandra; Rothen-Rutishauser, Barbara; Foster, E Johan; Weder, Christoph

    2016-05-26

    Hyaline cartilage is the nonlinear, inhomogeneous, anisotropic, poro-viscoelastic connective tissue that serves as friction-reducing and load-bearing cushion in synovial joints and is vital for mammalian skeletal movements. Due to its avascular nature, low cell density, low proliferative activity and the tendency of chondrocytes to de-differentiate, cartilage cannot regenerate after injury, wear and tear, or degeneration through common diseases such as osteoarthritis. Therefore severe damage usually requires surgical intervention. Current clinical strategies to generate new tissue include debridement, microfracture, autologous chondrocyte transplantation, and mosaicplasty. While articular cartilage was predicted to be one of the first tissues to be successfully engineered, it proved to be challenging to reproduce the complex architecture and biomechanical properties of the native tissue. Despite significant research efforts, only a limited number of studies have evolved up to the clinical trial stage. This review article summarizes the current state of cartilage tissue engineering in the context of relevant biological aspects, such as the formation and growth of hyaline cartilage, its composition, structure and biomechanical properties. Special attention is given to materials development, scaffold designs, fabrication methods, and template-cell interactions, which are of great importance to the structure and functionality of the engineered tissue.

  7. Hierarchical Design of Tissue Regenerative Constructs.

    Science.gov (United States)

    Rose, Jonas C; De Laporte, Laura

    2018-03-01

    The worldwide shortage of organs fosters significant advancements in regenerative therapies. Tissue engineering and regeneration aim to supply or repair organs or tissues by combining material scaffolds, biochemical signals, and cells. The greatest challenge entails the creation of a suitable implantable or injectable 3D macroenvironment and microenvironment to allow for ex vivo or in vivo cell-induced tissue formation. This review gives an overview of the essential components of tissue regenerating scaffolds, ranging from the molecular to the macroscopic scale in a hierarchical manner. Further, this review elaborates about recent pivotal technologies, such as photopatterning, electrospinning, 3D bioprinting, or the assembly of micrometer-scale building blocks, which enable the incorporation of local heterogeneities, similar to most native extracellular matrices. These methods are applied to mimic a vast number of different tissues, including cartilage, bone, nerves, muscle, heart, and blood vessels. Despite the tremendous progress that has been made in the last decade, it remains a hurdle to build biomaterial constructs in vitro or in vivo with a native-like structure and architecture, including spatiotemporal control of biofunctional domains and mechanical properties. New chemistries and assembly methods in water will be crucial to develop therapies that are clinically translatable and can evolve into organized and functional tissues. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Analysis of lung tissue using ion beams

    International Nuclear Information System (INIS)

    Alvarez, J.L.; Barrera, R.; Miranda, J.

    2002-01-01

    In this work a comparative study is presented of the contents of metals in lung tissue from healthy patients and with lung cancer, by means of two analytical techniques: Particle Induced X-ray Emission (PIXE) and Rutherford Backscattering Spectrometry (RBS). The samples of cancerous tissue were taken from 26 autopsies made to individuals died in the National Institute of Respiratory Disease (INER), 22 of cancer and 4 of other non-cancer biopsies. When analyzing the entirety of the samples, in the cancerous tissues, there were increments in the concentrations of S (4%), K (635%), Co (85%) and Cu (13%). Likewise, there were deficiencies in the concentrations of Cl (59%), Ca (6%), Fe (26%) and Zn (7%). Only in the cancerous tissues there were appearances of P, Ca, Ti, V, Cr, Mn, Ni, Br and Sr. The tissue samples were classified according to cancer types (adenocarcinomas, epidermoides and of small cell carcinoma), personal habits (smokers and alcoholic), genetic predisposition and residence place. There was a remarkable decrease in the concentration of Ca and a marked increment in the Cu in the epidermoide tissue samples with regard to those of adenocarcinoma or of small cells cancer. Also, decrements were detected in K and increments of Fe, Co and Cu in the sample belonging to people that resided in Mexico City with regard to those that resided in the State of Mexico

  9. Radionuclide imaging of soft tissue neoplasms

    International Nuclear Information System (INIS)

    Chew, F.S.; Hudson, T.M.; Enneking, W.F.

    1981-01-01

    Two classes of radiopharmaceuticals may be used for imaging tumors of the musculoskeletal system. The first is comprised of soft tissue or tumor specific agents such as gallium-67, bleomycin, and radionuclide-labeled antibodies, which may be useful for detecting and localizing these tumors. The other class of tracer is comprised of those with avidity for bone. The 99mTc-labeled-phosphate skeletal imaging compounds have been found to localize in a variety of soft tissue lesions, including benign and malignant tumors. In 1972, Enneking began to include bone scans in the preoperative evaluation of soft tissue masses. Later, he and his associates reported that these scans were useful in planning operative treatment of sarcomas by detecting involvement of bone by the tumors. Nearly all malignant soft tissue tumors take up bone-seeking radiopharmaceuticals, and bone involvement was indicated in two-thirds of the scans we reviewed. About half of benign soft tissue lesions had normal scans, but the other half showed uptake within the lesion and a few also showed bone involvement. Careful, thorough imaging technique is essential to proper evaluation. Multiple, high-resolution static gamma camera images in different projections are necessary to adequately demonstrate the presence or absence of soft tissue abnormality and to define the precise relationship of the tumor to the adjacent bone

  10. 21 CFR 1271.150 - Current good tissue practice requirements.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Current good tissue practice requirements. 1271... HUMAN CELLS, TISSUES, AND CELLULAR AND TISSUE-BASED PRODUCTS Current Good Tissue Practice § 1271.150 Current good tissue practice requirements. (a) General. This subpart D and subpart C of this part set...

  11. TRANSPLANTATION AND POTENTIAL IMMORTALITY OF MAMMALIAN TISSUES.

    Science.gov (United States)

    Loeb, L

    1926-06-20

    1. Serial transplantation of tumors made it possible in 1901 and following years to draw the conclusion that various mammalian tissues have potential immortality. Serial transplantations of normal tissues did not succeed at first, because the homoioreaction on the part of the lymphocytes and connective tissue of the host injures the transplant. 2. In continuation of these experiments we found that cartilage of the rat can be transplanted serially to other rats at least for a period of 3 years. At the end of that time great parts of the transplanted cartilage and perichondrium are alive. 3. Not only the cartilage of young rats can be homoiotransplanted, but also the cartilage of very old rats which are nearing the end of life. By using such animals we have been able to obtain cartilage and perichondrium approaching an age of 6 years which is almost double the average age of a rat. 4. We found that cartilage can be homoiotransplanted more readily than other tissues for the following reasons: (a) While in principle the homoioreaction towards cartilage is the same as against other tissues, cartilage elicits this reaction with less intensity; (b) cartilage is better able to resist the invasion of lymphocytes and connective tissue than the majority of other tissues; (c) a gradual adaptation between transplant and host seems to take place in the case of cartilage transplantation, as a result of which the lymphocytic reaction on the part of the host tissue decreases progressively the longer the cartilage is kept in the strange host. 5. At time of examination we not only found living transplanted cartilage tissue, but also perichondrial tissue, which in response to a stimulus apparently originating in the necrotic central cartilage, had been proliferating and replacing it. These results suggest that it may perhaps be possible under favorable conditions to keep cartilage alive indefinitely through serial transplantations. 6. At the same time these experiments permit the

  12. Methamphetamine and amphetamine concentrations in postmortem rabbit tissues.

    Science.gov (United States)

    Nagata, T; Kimura, K; Hara, K; Kudo, K

    1990-11-01

    The feasibility of detecting methamphetamine and its major metabolite, amphetamine, in postmortem tissues over a 2-year period was examined. It is important to determine if the abuse and toxic effects of drugs can be proved from evidence found in decayed, submerged, or stained tissue materials. The blood, urine, liver, skeletal muscle, skin and extremity bones from rabbits given methamphetamine intravenously were kept at room temperature, under 4 different conditions: sealed in a test tube, dried in the open air, submerged in tap water and stained on gauze. Methamphetamine was present in all the samples, with slight change in concentration in case of sealed and air dried tissues. Changes varied in bones kept in water. There were considerable decreases in methamphetamine in blood and urine stains. Despite long term storage, drug abuse and/or toxicity could be determined, in all tissues examined.

  13. Effects of pressure rise on cw laser ablation of tissue

    Science.gov (United States)

    LeCarpentier, Gerald L.; Motamedi, Massoud; Welch, Ashley J.

    1991-06-01

    The objectives of this research were to identify mechanisms responsible for the initiation of continuous wave (cw) laser ablation of tissue and investigate the role of pressure in the ablation process. Porcine aorta samples were irradiated in a chamber pressurized from 1 X 10-4 to 12 atmospheres absolute pressure. Acrylic and Zn-Se windows in the experimental pressure chamber allowed video and infrared cameras to simultaneously record mechanical and thermal events associated with cw argon laser ablation of these samples. Video and thermal images of tissue slabs documented the explosive nature of cw laser ablation of soft biological media and revealed similar ablation threshold temperatures and ablation onset times under different environmental pressures; however, more violent initiation explosions with decreasing environmental pressures were observed. These results suggest that ablation initiates with thermal alterations in the mechanical strength of the tissue and proceeds with an explosion induced by the presence superheated liquid within the tissue.

  14. Pulp and periodontal tissue repair - regeneration or tissue metaplasia after dental trauma. A review

    DEFF Research Database (Denmark)

    Andreasen, Jens O

    2012-01-01

    Healing subsequent to dental trauma is known to be very complex, a result explained by the variability of the types of dental trauma (six luxations, nine fracture types, and their combinations). On top of that, at least 16 different cellular systems get involved in more severe trauma types each o...... of tissue replaces the injured). In this study, a review is given of the impact of trauma to various dental tissues such as alveolar bone, periodontal ligament, cementum, Hertvigs epithelial root sheath, and the pulp....... of them with a different potential for healing with repair, i.e. (re-establishment of tissue continuity without functional restitution) and regeneration (where the injured or lost tissue is replaced with new tissue with identical tissue anatomy and function) and finally metaplasia (where a new type...

  15. Tissue/blood partition coefficients for xenon in various adipose tissue depots in man

    DEFF Research Database (Denmark)

    Bülow, J; Jelnes, Rolf; Astrup, A

    1987-01-01

    Tissue/blood partition coefficients (lambda) for xenon were calculated for subcutaneous adipose tissue from the abdominal wall and the thigh, and for the perirenal adipose tissue after chemical analysis of the tissues for lipid, water and protein content. The lambda in the perirenal tissue...... was found to correlate linearly to the relative body weight (RBW) in per cent with the regression equation lambda = 0.045 . RBW + 0.99. The subcutaneous lambda on the abdomen correlated linearly to the local skinfold thickness (SFT) with the equation lambda = 0.22 SFT + 2.99. Similarly lambda on the thigh...... correlated to SFT with the equation lambda = 0.20 . SFT + 4.63. It is concluded that the previously accepted lambda value of 10 is generally too high in perirenal as well as in subcutaneous tissue. Thus, by application of the present regression equations, it is possible to obtain more exact estimates...

  16. Nanoreinforced Hydrogels for Tissue Engineering: Biomaterials that are Compatible with Load-Bearing and Electroactive Tissues

    DEFF Research Database (Denmark)

    Mehrali, Mehdi; Thakur, Ashish; Pennisi, Christian Pablo

    2017-01-01

    , mechanical, and electrical properties. Here, recent advances in the fabrication and application of nanocomposite hydrogels in tissue engineering applications are described, with specific attention toward skeletal and electroactive tissues, such as cardiac, nerve, bone, cartilage, and skeletal muscle......Given their highly porous nature and excellent water retention, hydrogel-based biomaterials can mimic critical properties of the native cellular environment. However, their potential to emulate the electromechanical milieu of native tissues or conform well with the curved topology of human organs...

  17. Soft tissue twisting injuries of the knee

    International Nuclear Information System (INIS)

    Magee, T.; Shapiro, M.

    2001-01-01

    Twisting injuries occur as a result of differential motion of different tissue types in injuries with some rotational force. These injuries are well described in brain injuries but, to our knowledge, have not been described in the musculoskeletal literature. We correlated the clinical examination and MR findings of 20 patients with twisting injuries of the soft tissues around the knee. Design and patients: We prospectively followed the clinical courses of 20 patients with knee injuries who had clinical histories and MR findings to suggest twisting injuries of the subcutaneous tissues. Patients with associated internal derangement of the knee (i.e., meniscal tears, ligamentous or bone injuries) were excluded from this study. MR findings to suggest twisting injuries included linear areas of abnormal dark signal on T1-weighted sequences and abnormal bright signal on T2-weighted or short tau inversion recovery (STIR) sequences and/or signal to suggest hemorrhage within the subcutaneous tissues. These MR criteria were adapted from those established for indirect musculotendinous junction injuries. Results: All 20 patients presented with considerable pain that suggested internal derangement on physical examination by the referring orthopedic surgeons. All presented with injuries associated with rotational force. The patients were placed on a course of protected weight-bearing of the affected extremity for 4 weeks. All patients had pain relief by clinical examination after this period of protected weight-bearing. Twisting injuries of the soft tissues can result in considerable pain that can be confused with internal derangement of the knee on physical examination. Soft tissue twisting injuries need to be recognized on MR examinations as they may be the cause of the patient's pain despite no MR evidence of internal derangement of the knee. The demonstration of soft tissue twisting injuries in a patient with severe knee pain but no documented internal derangement on MR

  18. Kininase enzymes of cat eye tissues

    International Nuclear Information System (INIS)

    Ryan, J.W.; Anderson, D.R.

    1986-01-01

    Eye tissues contain kininase activities, including an angiotensin converting enzyme (ACE)-like activity. The authors have begun further to characterize the ACE-like activity and to examine for another reputed kininase, carboxypeptidase N (CPN). Homogenates of tissues of 6 cat eyes and paired plasmas were assayed for ACE using 3 acyl-tripeptide substrates, 3 H-benzoylated F-A-P, F-G-P and A-G-P (respectively, BFAP, BFGP and BAGP). CPN was assayed using 3 H-benzoyl-A-R. All eye tissues and fluids contained ACE- and CPN-like activities. The ACE activity was clearly owing to ACE: relative values of Kc/Km for BFAP, BFGP and BAGP were those for pure ACE (2.213, 1.751 and 1.0); reactivities with inhibitors were as expected (Ki for captopril, MK 422 and RAC-X-65: 2.7, 0.62 and 0.31 nM). EDTA inhibited both ACE and CPN (I 50 's: 43 and 47 μM). CPN activity was inhibited by 2-mercaptomethyl-3-guanidinoethylthiopropionate (Ki 2.4 nM). However, distributions of the two enzymes differed markedly. Virtually all tissues contained ACE at specific activities higher than that of plasma. Specific activities appeared to be a function of tissue vascularity (for choroid, ciliary body, iris, retina and plasma: 7.31, 2.57, 1.98, 1.53 and 0.21 pmol/mg protein). Only iris contained more CPN that did plasma (23.0 v. 7.21 pmol/mg protein). The tissue distribution of ACE is that expected for an endothelial-associated enzyme. Plasma may be the major source of CPN in eye tissues other than iris

  19. Realistic tissue visualization using photoacoustic image

    Science.gov (United States)

    Cho, Seonghee; Managuli, Ravi; Jeon, Seungwan; Kim, Jeesu; Kim, Chulhong

    2018-02-01

    Visualization methods are very important in biomedical imaging. As a technology that understands life, biomedical imaging has the unique advantage of providing the most intuitive information in the image. This advantage of biomedical imaging can be greatly improved by choosing a special visualization method. This is more complicated in volumetric data. Volume data has the advantage of containing 3D spatial information. Unfortunately, the data itself cannot directly represent the potential value. Because images are always displayed in 2D space, visualization is the key and creates the real value of volume data. However, image processing of 3D data requires complicated algorithms for visualization and high computational burden. Therefore, specialized algorithms and computing optimization are important issues in volume data. Photoacoustic-imaging is a unique imaging modality that can visualize the optical properties of deep tissue. Because the color of the organism is mainly determined by its light absorbing component, photoacoustic data can provide color information of tissue, which is closer to real tissue color. In this research, we developed realistic tissue visualization using acoustic-resolution photoacoustic volume data. To achieve realistic visualization, we designed specialized color transfer function, which depends on the depth of the tissue from the skin. We used direct ray casting method and processed color during computing shader parameter. In the rendering results, we succeeded in obtaining similar texture results from photoacoustic data. The surface reflected rays were visualized in white, and the reflected color from the deep tissue was visualized red like skin tissue. We also implemented the CUDA algorithm in an OpenGL environment for real-time interactive imaging.

  20. Toward real-time temperature monitoring in fat and aqueous tissue during magnetic resonance-guided high-intensity focused ultrasound using a three-dimensional proton resonance frequency T1 method.

    Science.gov (United States)

    Diakite, Mahamadou; Odéen, Henrik; Todd, Nick; Payne, Allison; Parker, Dennis L

    2014-07-01

    To present a three-dimensional (3D) segmented echoplanar imaging (EPI) pulse sequence implementation that provides simultaneously the proton resonance frequency shift temperature of aqueous tissue and the longitudinal relaxation time (T1 ) of fat during thermal ablation. The hybrid sequence was implemented by combining a 3D segmented flyback EPI sequence, the extended two-point Dixon fat and water separation, and the double flip angle T1 mapping techniques. High-intensity focused ultrasound (HIFU) heating experiments were performed at three different acoustic powers on excised human breast fat embedded in ex vivo porcine muscle. Furthermore, T1 calibrations with temperature in four different excised breast fat samples were performed, yielding an estimate of the average and variation of dT1 /dT across subjects. The water only images were used to mask the complex original data before computing the proton resonance frequency shift. T1 values were calculated from the fat-only images. The relative temperature coefficients were found in five fat tissue samples from different patients and ranged from 1.2% to 2.6%/°C. The results demonstrate the capability of real-time simultaneous temperature mapping in aqueous tissue and T1 mapping in fat during HIFU ablation, providing a potential tool for treatment monitoring in organs with large fat content, such as the breast. Copyright © 2013 Wiley Periodicals, Inc.

  1. Bioactive scaffolds for the controlled formation of complex skeletal tissues

    NARCIS (Netherlands)

    Hofmann, S.; Garcia-Fuentes, M.; Eberli, D.

    2011-01-01

    Tissue Engineering may offer new treatment alternatives for organ replacement or repair deteriorated organs. Among the clinical applications of Tissue Engineering are the production of artificial skin for burn patients, tissue engineered trachea, cartilage for knee-replacement procedures, urinary

  2. [Biofabrication: new approaches for tissue regeneration].

    Science.gov (United States)

    Horch, Raymund E; Weigand, Annika; Wajant, Harald; Groll, Jürgen; Boccaccini, Aldo R; Arkudas, Andreas

    2018-04-01

    The advent of Tissue Engineering (TE) in the early 1990ies was fostered by the increasing need for functional tissue and organ replacement. Classical TE was based on the combination of carrier matrices, cells and growth factors to reconstitute lost or damaged tissue and organs. Despite considerable results in vitro and in experimental settings the lack of early vascularization has hampered its translation into daily clinical practice so far. A new field of research, called "biofabrication" utilizing latest 3D printing technologies aims at hierarchically and spatially incorporating different cells, biomaterials and molecules into a matrix to alleviate a directed maturation of artificial tissue. A literature research of the relevant publications regarding biofabrication and bioprinting was performed using the PubMed data base. Relevant papers were selected and evaluated with secondary analysis of specific citations on the bioprinting techniques. 180 relevant papers containing the key words were identified and evaluated. Basic principles into the developing field of bioprinting technology could be discerned. Key elements comprise the high-throughput assembly of cells and the fabrication of complex and functional hierarchically organized tissue constructs. Five relevant technological principles for bioprinting were identified, such as stereolithography, extrusion-based printing, laser-assisted printing, inkjet-based printing and nano-bioprinting. The different technical methods of 3D printing were found to be associated with various positive but also negative effects on cells and proteins during the printing process. Research efforts in this field obviously aim towards the development of optimizing the so called bioinks and the printing technologies. This review details the evolution of the classical methods of TE in Regenerative Medicine into the evolving field of biofabrication by bioprinting. The advantages of 3D bioprinting over traditional tissue engineering

  3. Bone Tissue Donation: Tendency and Hurdles.

    Science.gov (United States)

    El Hage, S; Dos Santos, M J; de Moraes, E L; de Barros E Silva, L B

    2018-03-01

    The aim of this study was to identify the percentage of bone tissue donation in a brain death situation and the tendency of donation rate of this tissue in an organ procurement organization in the county of Sao Paulo from 2001 to 2016. It is a retrospective and quantitative study, based on the Organ and Tissue Donation Term of donors who died of brain death between 2001 and 2016. A logistic regression model was applied, and the odds of donation were identified throughout the years, regarding the odds ratio different from zero. Finally, it was measured the accuracy of the odds ratio through the confidence interval. The analysis has shown a significant change on the trend of bone donation (P 1, indicating that the donation rate has increased. However, the percentage of growth is still considered low. The study evidences a growth trend regarding the donation of bone tissue, but the percentage is still too low to adequately meet the demand of patients who need this modality of therapeutic intervention. It is believed that educational campaigns of donation are not emphasizing the donation of tissues for transplantation, which may be directly impacting their consent rates. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Recombinant protein scaffolds for tissue engineering

    International Nuclear Information System (INIS)

    Werkmeister, Jerome A; Ramshaw, John A M

    2012-01-01

    New biological materials for tissue engineering are now being developed using common genetic engineering capabilities to clone and express a variety of genetic elements that allow cost-effective purification and scaffold fabrication from these recombinant proteins, peptides or from chimeric combinations of these. The field is limitless as long as the gene sequences are known. The utility is dependent on the ease, product yield and adaptability of these protein products to the biomedical field. The development of recombinant proteins as scaffolds, while still an emerging technology with respect to commercial products, is scientifically superior to current use of natural materials or synthetic polymer scaffolds, in terms of designing specific structures with desired degrees of biological complexities and motifs. In the field of tissue engineering, next generation scaffolds will be the key to directing appropriate tissue regeneration. The initial period of biodegradable synthetic scaffolds that provided shape and mechanical integrity, but no biological information, is phasing out. The era of protein scaffolds offers distinct advantages, particularly with the combination of powerful tools of molecular biology. These include, for example, the production of human proteins of uniform quality that are free of infectious agents and the ability to make suitable quantities of proteins that are found in low quantity or are hard to isolate from tissue. For the particular needs of tissue engineering scaffolds, fibrous proteins like collagens, elastin, silks and combinations of these offer further advantages of natural well-defined structural scaffolds as well as endless possibilities of controlling functionality by genetic manipulation. (topical review)

  5. Tissue engineering and regenerative medicine: manufacturing challenges.

    Science.gov (United States)

    Williams, D J; Sebastine, I M

    2005-12-01

    Tissue engineering and regenerative medicine are interdisciplinary fields that apply principles of engineering and life sciences to develop biological substitutes, typically composed of biological and synthetic components, that restore, maintain or improve tissue function. Many tissue engineering technologies are still at a laboratory or pre-commercial scale. The short review paper describes the most significant manufacturing and bio-process challenges inherent in the commercialisation and exploitation of the exciting results emerging from the biological and clinical laboratories exploring tissue engineering and regenerative medicine. A three-generation road map of the industry has been used to structure a view of these challenges and to define where the manufacturing community can contribute to the commercial success of the products from these emerging fields. The first-generation industry is characterised by its demonstrated clinical applications and products in the marketplace, the second is characterised by emerging clinical applications, and the third generation is characterised by aspirational clinical applications. The paper focuses on the cost reduction requirement of the first generation of the industry to allow more market penetration and consequent patient impact. It indicates the technological requirements, for instance the creation of three-dimensional tissue structures, and value chain issues in the second generation of the industry. The third-generation industry challenges lie in fundamental biological and clinical science. The paper sets out a road map of these generations to identify areas for research.

  6. Measurement of tissue viscoelasticity with ultrasound

    Science.gov (United States)

    Greenleaf, J. F.; Alizad, A.

    2017-02-01

    Tissue properties such as elasticity and viscosity have been shown to be related to such tissue conditions as contraction, edema, fibrosis, and fat content among others. Magnetic Resonance Elastography has shown outstanding ability to measure the elasticity and in some cases the viscosity of tissues, especially in the liver, providing the ability to stage fibrotic liver disease similarly to biopsy. We discuss ultrasound methods of measuring elasticity and viscosity in tissues. Many of these methods are becoming widely available in the extant ultrasound machines distributed throughout the world. Some of the methods to be discussed are in the developmental stage. The advantages of the ultrasound methods are that the imaging instruments are widely available and that many of the viscoelastic measurements can be made during a short addition to the normal ultrasound examination time. In addition, the measurements can be made by ultrasound repetitively and quickly allowing evaluation of dynamic physiologic function in circumstances such as muscle contraction or artery relaxation. Measurement of viscoelastic tissue mechanical properties will become a consistent part of clinical ultrasound examinations in our opinion.

  7. Human normal tissue reactions in radiotherapy

    International Nuclear Information System (INIS)

    Taniike, Keiko

    1990-01-01

    Acute and late normal tissue reactions in radiotherapy have not been considered to be major problems with conventional fractionation. But they may cause certain problems when newer schedules such as hyperfractionation or accelerated fractionation are used. In opposing parallel radiotherapy, the dose fractionation of skin or subcutaneous connective tissue are different between in one portal and two portals daily. So we examined acute skin erythema and late connective tissue fibrosis in the two groups (one and two portals) of the patients with uterus cancer. Acute skin erythema and late connective tissue fibrosis were slightly stronger in case of one portal daily. In relation to the anatomical site of skin, acute skin erythema was stronger at the buttocks than the lower abdomen, but late fibrosis was reverse to that. So the degree of acute skin erythema did not predict the degree of late connective tissue fibrosis. The number of Time Dose Fractionation Factor could roughly estimate the degree of erythema and fibrosis. Late fibrosis in 36 fractions increased with an increase of abdominal thickness, but acute erythema did not. (author)

  8. MicroRNAs in skin tissue engineering.

    Science.gov (United States)

    Miller, Kyle J; Brown, David A; Ibrahim, Mohamed M; Ramchal, Talisha D; Levinson, Howard

    2015-07-01

    35.2 million annual cases in the U.S. require clinical intervention for major skin loss. To meet this demand, the field of skin tissue engineering has grown rapidly over the past 40 years. Traditionally, skin tissue engineering relies on the "cell-scaffold-signal" approach, whereby isolated cells are formulated into a three-dimensional substrate matrix, or scaffold, and exposed to the proper molecular, physical, and/or electrical signals to encourage growth and differentiation. However, clinically available bioengineered skin equivalents (BSEs) suffer from a number of drawbacks, including time required to generate autologous BSEs, poor allogeneic BSE survival, and physical limitations such as mass transfer issues. Additionally, different types of skin wounds require different BSE designs. MicroRNA has recently emerged as a new and exciting field of RNA interference that can overcome the barriers of BSE design. MicroRNA can regulate cellular behavior, change the bioactive milieu of the skin, and be delivered to skin tissue in a number of ways. While it is still in its infancy, the use of microRNAs in skin tissue engineering offers the opportunity to both enhance and expand a field for which there is still a vast unmet clinical need. Here we give a review of skin tissue engineering, focusing on the important cellular processes, bioactive mediators, and scaffolds. We further discuss potential microRNA targets for each individual component, and we conclude with possible future applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. 3D bioprinting for engineering complex tissues.

    Science.gov (United States)

    Mandrycky, Christian; Wang, Zongjie; Kim, Keekyoung; Kim, Deok-Ho

    2016-01-01

    Bioprinting is a 3D fabrication technology used to precisely dispense cell-laden biomaterials for the construction of complex 3D functional living tissues or artificial organs. While still in its early stages, bioprinting strategies have demonstrated their potential use in regenerative medicine to generate a variety of transplantable tissues, including skin, cartilage, and bone. However, current bioprinting approaches still have technical challenges in terms of high-resolution cell deposition, controlled cell distributions, vascularization, and innervation within complex 3D tissues. While no one-size-fits-all approach to bioprinting has emerged, it remains an on-demand, versatile fabrication technique that may address the growing organ shortage as well as provide a high-throughput method for cell patterning at the micrometer scale for broad biomedical engineering applications. In this review, we introduce the basic principles, materials, integration strategies and applications of bioprinting. We also discuss the recent developments, current challenges and future prospects of 3D bioprinting for engineering complex tissues. Combined with recent advances in human pluripotent stem cell technologies, 3D-bioprinted tissue models could serve as an enabling platform for high-throughput predictive drug screening and more effective regenerative therapies. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Circadian clocks are resounding in peripheral tissues.

    Directory of Open Access Journals (Sweden)

    Andrey A Ptitsyn

    2006-03-01

    Full Text Available Circadian rhythms are prevalent in most organisms. Even the smallest disturbances in the orchestration of circadian gene expression patterns among different tissues can result in functional asynchrony, at the organism level, and may to contribute to a wide range of physiologic disorders. It has been reported that as many as 5%-10% of transcribed genes in peripheral tissues follow a circadian expression pattern. We have conducted a comprehensive study of circadian gene expression on a large dataset representing three different peripheral tissues. The data have been produced in a large-scale microarray experiment covering replicate daily cycles in murine white and brown adipose tissues as well as in liver. We have applied three alternative algorithmic approaches to identify circadian oscillation in time series expression profiles. Analyses of our own data indicate that the expression of at least 7% to 21% of active genes in mouse liver, and in white and brown adipose tissues follow a daily oscillatory pattern. Indeed, analysis of data from other laboratories suggests that the percentage of genes with an oscillatory pattern may approach 50% in the liver. For the rest of the genes, oscillation appears to be obscured by stochastic noise. Our phase classification and computer simulation studies based on multiple datasets indicate no detectable boundary between oscillating and non-oscillating fractions of genes. We conclude that greater attention should be given to the potential influence of circadian mechanisms on any biological pathway related to metabolism and obesity.

  11. Inert gas transport in blood and tissues.

    Science.gov (United States)

    Baker, A Barry; Farmery, Andrew D

    2011-04-01

    This article establishes the basic mathematical models and the principles and assumptions used for inert gas transfer within body tissues-first, for a single compartment model and then for a multicompartment model. From these, and other more complex mathematical models, the transport of inert gases between lungs, blood, and other tissues is derived and compared to known experimental studies in both animals and humans. Some aspects of airway and lung transfer are particularly important to the uptake and elimination of inert gases, and these aspects of gas transport in tissues are briefly described. The most frequently used inert gases are those that are administered in anesthesia, and the specific issues relating to the uptake, transport, and elimination of these gases and vapors are dealt with in some detail showing how their transfer depends on various physical and chemical attributes, particularly their solubilities in blood and different tissues. Absorption characteristics of inert gases from within gas cavities or tissue bubbles are described, and the effects other inhaled gas mixtures have on the composition of these gas cavities are discussed. Very brief consideration is given to the effects of hyper- and hypobaric conditions on inert gas transport. © 2011 American Physiological Society. Compr Physiol 1:569-592, 2011.

  12. Injectable biomaterials for adipose tissue engineering

    International Nuclear Information System (INIS)

    Young, D A; Christman, K L

    2012-01-01

    Adipose tissue engineering has recently gained significant attention from materials scientists as a result of the exponential growth of soft tissue filler procedures being performed within the clinic. While several injectable materials are currently being marketed for filling subcutaneous voids, they often face limited longevity due to rapid resorption. Their inability to encourage natural adipose formation or ingrowth necessitates repeated injections for a prolonged effect and thus classifies them as temporary fillers. As a result, a significant need for injectable materials that not only act as fillers but also promote in vivo adipogenesis is beginning to be realized. This paper will discuss the advantages and disadvantages of commercially available soft tissue fillers. It will then summarize the current state of research using injectable synthetic materials, biopolymers and extracellular matrix-derived materials for adipose tissue engineering. Furthermore, the successful attributes observed across each of these materials will be outlined along with a discussion of the current difficulties and future directions for adipose tissue engineering. (paper)

  13. Esophageal tissue engineering: Current status and perspectives.

    Science.gov (United States)

    Poghosyan, T; Catry, J; Luong-Nguyen, M; Bruneval, P; Domet, T; Arakelian, L; Sfeir, R; Michaud, L; Vanneaux, V; Gottrand, F; Larghero, J; Cattan, P

    2016-02-01

    Tissue engineering, which consists of the combination and in vivo implantation of elements required for tissue remodeling toward a specific organ phenotype, could be an alternative for classical techniques of esophageal replacement. The current hybrid approach entails creation of an esophageal substitute composed of an acellular matrix and autologous epithelial and muscle cells provides the most successful results. Current research is based on the use of mesenchymal stem cells, whose potential for differentiation and proangioogenic, immune-modulator and anti-inflammatory properties are important assets. In the near future, esophageal substitutes could be constructed from acellular "intelligent matrices" that contain the molecules necessary for tissue regeneration; this should allow circumvention of the implantation step and still obtain standardized in vivo biological responses. At present, tissue engineering applications to esophageal replacement are limited to enlargement plasties with absorbable, non-cellular matrices. Nevertheless, the application of existing clinical techniques for replacement of other organs by tissue engineering in combination with a multiplication of translational research protocols for esophageal replacement in large animals should soon pave the way for health agencies to authorize clinical trials. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  14. Tissue adhesives for simple traumatic lacerations.

    Science.gov (United States)

    Beam, Joel W

    2008-01-01

    Farion K, Osmond MH, Hartling L, et al. Tissue adhesives for traumatic lacerations in children and adults. Cochrane Database Syst Rev. 2001(4);CD003326. What is the clinical evidence base for tissue adhesives in the management of simple traumatic lacerations? Studies were identified by searches of the following databases: Cochrane Wounds Group Specialized Trials Register (September 2003), Cochrane Central Register of Controlled Trials (CENTRAL) (CDROM 2003, issue 3), MEDLINE (1966 to September 2003, week 1), EMBASE (1988 to 2003, week 36), Web of Science Science Citation Index (1975 to September 13, 2003) and various clinical trials registers (September 2003). Investigators and product manufacturers were contacted to identify additional eligible studies. The search terms included wounds and injuries, laceration, face injury, nose injury, tissue adhesives, and acrylates. Each study fulfilled the following criteria: (1) The study was a randomized controlled trial that compared tissue adhesives with standard wound closure (SWC) (sutures, staples, adhesive strips) or tissue adhesive with tissue adhesive. (2) The wounds were acute, linear lacerations less than 12 hours old, resulting from blunt or sharp trauma. (3) The wound length, width, and depth allowed for approximation of the edges with minimal tension after deep sutures were placed, if required. Studies were included with no language or publication status restriction, with participants of any age recruited in an emergency department, outpatient clinic, walk-in clinic, or other primary care setting. Studies were excluded if the wounds were stellate lacerations, puncture wounds, mammalian bites, infected, heavily contaminated or devitalized, crossing joints or mucocutaneous junctions, in hair-bearing areas, or in patients with keloid formation or chronic illness. The characteristics of the study and participants, interventions, outcome measures, and findings were extracted by one author and verified by a second

  15. A newly developed container for safe, easy, and cost-effective overnight transportation of tissues and organs by electrically keeping tissue or organ temperature at 3 to 6°C.

    Science.gov (United States)

    Ohkawara, H; Kitagawa, T; Fukushima, N; Ito, T; Sawa, Y; Yoshimine, T

    2012-05-01

    As there is only one skin procurement organization in Japan the Japan Skin Bank Network (JSBN), all skin grafts procured in Japan are sent by a commercialized delivery system. Preliminarily, bottles containing saline were transported in a cardboard box using a so-called "cooled home delivery service" using a truck with a refrigerated cargo container. During transportation the temperature in the cardboard box increased to 18°C in summer and decreased to -5°C in winter. For these reasons, we investigated whether a newly developed container "Medi Cube" would be useful to transport skin grafts. Four bottles with a capacity of 300 mL containing 150 mL of saline in a Medi Cube container were transported from Osaka to the JSBN in Tokyo between 4 PM and 10 AM using a commercialized cooled home delivery service. Two bottles were transported in a Medi Cube container without phase change materials (PCM) in winter and summer, respectively. Another two bottles were transported in the Medi Cube with PCMs in winter. The temperatures inside saline, inside a transportation container, and outside the container, and air temperature were monitored continuously with a recordable thermometer. The temperatures inside saline and inside a Medi Cube container were maintained between 3 and 6°C, even when the temperature outside the container increased during parking. The temperature inside a Medi Cube container without PCM decreased to -3°C when the inside of the cargo container was overcooled in winter. However, the temperatures inside saline and inside a Medi Cube container with PCM were between 3 and 6°C, even when the temperature outside the container decreased to below 0°C in winter. A Medi Cube container with PCM provided a safe, easy, and cost-effective method for overnight transportation of skin grafts. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Quantitative characterization of viscoelastic behavior in tissue-mimicking phantoms and ex vivo animal tissues.

    Directory of Open Access Journals (Sweden)

    Ashkan Maccabi

    Full Text Available Viscoelasticity of soft tissue is often related to pathology, and therefore, has become an important diagnostic indicator in the clinical assessment of suspect tissue. Surgeons, particularly within head and neck subsites, typically use palpation techniques for intra-operative tumor detection. This detection method, however, is highly subjective and often fails to detect small or deep abnormalities. Vibroacoustography (VA and similar methods have previously been used to distinguish tissue with high-contrast, but a firm understanding of the main contrast mechanism has yet to be verified. The contributions of tissue mechanical properties in VA images have been difficult to verify given the limited literature on viscoelastic properties of various normal and diseased tissue. This paper aims to investigate viscoelasticity theory and present a detailed description of viscoelastic experimental results obtained in tissue-mimicking phantoms (TMPs and ex vivo tissues to verify the main contrast mechanism in VA and similar imaging modalities. A spherical-tip micro-indentation technique was employed with the Hertzian model to acquire absolute, quantitative, point measurements of the elastic modulus (E, long term shear modulus (η, and time constant (τ in homogeneous TMPs and ex vivo tissue in rat liver and porcine liver and gallbladder. Viscoelastic differences observed between porcine liver and gallbladder tissue suggest that imaging modalities which utilize the mechanical properties of tissue as a primary contrast mechanism can potentially be used to quantitatively differentiate between proximate organs in a clinical setting. These results may facilitate more accurate tissue modeling and add information not currently available to the field of systems characterization and biomedical research.

  17. Quantitative characterization of viscoelastic behavior in tissue-mimicking phantoms and ex vivo animal tissues.

    Science.gov (United States)

    Maccabi, Ashkan; Shin, Andrew; Namiri, Nikan K; Bajwa, Neha; St John, Maie; Taylor, Zachary D; Grundfest, Warren; Saddik, George N

    2018-01-01

    Viscoelasticity of soft tissue is often related to pathology, and therefore, has become an important diagnostic indicator in the clinical assessment of suspect tissue. Surgeons, particularly within head and neck subsites, typically use palpation techniques for intra-operative tumor detection. This detection method, however, is highly subjective and often fails to detect small or deep abnormalities. Vibroacoustography (VA) and similar methods have previously been used to distinguish tissue with high-contrast, but a firm understanding of the main contrast mechanism has yet to be verified. The contributions of tissue mechanical properties in VA images have been difficult to verify given the limited literature on viscoelastic properties of various normal and diseased tissue. This paper aims to investigate viscoelasticity theory and present a detailed description of viscoelastic experimental results obtained in tissue-mimicking phantoms (TMPs) and ex vivo tissues to verify the main contrast mechanism in VA and similar imaging modalities. A spherical-tip micro-indentation technique was employed with the Hertzian model to acquire absolute, quantitative, point measurements of the elastic modulus (E), long term shear modulus (η), and time constant (τ) in homogeneous TMPs and ex vivo tissue in rat liver and porcine liver and gallbladder. Viscoelastic differences observed between porcine liver and gallbladder tissue suggest that imaging modalities which utilize the mechanical properties of tissue as a primary contrast mechanism can potentially be used to quantitatively differentiate between proximate organs in a clinical setting. These results may facilitate more accurate tissue modeling and add information not currently available to the field of systems characterization and biomedical research.

  18. Tissue banking and clinical research on radiation and ethylene oxide sterilization of tissue grafts

    International Nuclear Information System (INIS)

    Pe Khin

    1987-06-01

    The research works carried out in Rangoon, Burma under the Agency supported project RC4420/RB have dealt with an elucidation of the radiation interaction(s) with the species of biomolecules such as proteins, lipids, collagens, connective tissues present in the cleaned and freeze-dried non-viable tissue grafts. Radiation as a cool process furthermore effectively helps to destroy the microbial bioburden as the undesirable contaminants which may associate the tissue grafts. Radiation also concomitantly helps to suppress the tissue-specific immunogenicity. All these attributes of radiation induced effects have proved successful towards the development of a sterilization process. A series of non-viable tissue grafts, such as bone, nerve, fascia, dura, cartilage, chorion-amnion (as dressings in burn wounds) and tympanic membrane have been successfully attempted in Burma and many more possibilities seem to still remain unexplored. Radiation sterilization modality has proved as a blessing for the promotion of clinical surgical applications of tissue allografts in the corrective/reconstructive surgery on the disability cases due to diseases which accompany tissue losses. The investigator in Burma has reported on the case histories where freeze dried radiation sterilized tissue allografts have been successfully used in the osteogenic inductions (bone grafts); midear tympanoplasty; partial recovery of nerve sensation throught nerve allografts; rapid healing of high degree burn wounds through the use of amnion dressings. Besides, there have been a widespread surgical use of radiation sterilized dura and fascia as allografts. A national tissue banking facility has been established in Burma surrounding the processing and clinical utilization of tissue allografts which has involved over ten hospital centres throughout the country. Radiation induced effects on the biomolecules of clinical significance in the tissue grafts have been researched to help gain insight into a better

  19. Curriculum in biomedical optics and laser-tissue interactions

    Science.gov (United States)

    Jacques, Steven L.

    2003-10-01

    A graduate student level curriculum has been developed for teaching the basic principles of how lasers and light interact with biological tissues and materials. The field of Photomedicine can be divided into two topic areas: (1) where tissue affects photons, used for diagnostic sensing, imaging, and spectroscopy of tissues and biomaterials, and (2) where photons affect tissue, used for surgical and therapeutic cutting, dissecting, machining, processing, coagulating, welding, and oxidizing tissues and biomaterials. The courses teach basic principles of tissue optical properties and light transport in tissues, and interaction of lasers and conventional light sources with tissues via photochemical, photothermal and photomechanical mechanisms.

  20. Advances in polymeric systems for tissue engineering and biomedical applications.

    Science.gov (United States)

    Ravichandran, Rajeswari; Sundarrajan, Subramanian; Venugopal, Jayarama Reddy; Mukherjee, Shayanti; Ramakrishna, Seeram

    2012-03-01

    The characteristics of tissue engineered scaffolds are major concerns in the quest to fabricate ideal scaffolds for tissue engineering applications. The polymer scaffolds employed for tissue engineering applications should possess multifunctional properties such as biocompatibility, biodegradability and favorable mechanical properties as it comes in direct contact with the body fluids in vivo. Additionally, the polymer system should also possess biomimetic architecture and should support stem cell adhesion, proliferation and differentiation. As the progress in polymer technology continues, polymeric biomaterials have taken characteristics more closely related to that desired for tissue engineering and clinical needs. Stimuli responsive polymers also termed as smart biomaterials respond to stimuli such as pH, temperature, enzyme, antigen, glucose and electrical stimuli that are inherently present in living systems. This review highlights the exciting advancements in these polymeric systems that relate to biological and tissue engineering applications. Additionally, several aspects of technology namely scaffold fabrication methods and surface modifications to confer biological functionality to the polymers have also been discussed. The ultimate objective is to emphasize on these underutilized adaptive behaviors of the polymers so that novel applications and new generations of smart polymeric materials can be realized for biomedical and tissue engineering applications. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Laser tissue welding in ophthalmic surgery.

    Science.gov (United States)

    Rossi, Francesca; Matteini, Paolo; Ratto, Fulvio; Menabuoni, Luca; Lenzetti, Ivo; Pini, Roberto

    2008-09-01

    Laser welding of ocular tissues is an alternative technique or adjunct to conventional suturing in ophthalmic surgery. It is based on the photothermal interaction of laser light with the main components of the extracellular matrix of connective tissues. The advantages of the welding procedure with respect to standard suturing and stapling are reduced operation times, lesser inflammation, faster healing and increased ability to induce tissue regeneration. The procedure we set up is based on the use of an infrared diode laser in association with the topical application of the chromophore Indocyanine Green. Laser light may be delivered either continuously or in pulses, thus identifying two different techniques that have been applied clinically in various types of transplants of the cornea.

  2. Electrospinning of Nanofibers for Tissue Engineering Applications

    Directory of Open Access Journals (Sweden)

    Haifeng Liu

    2013-01-01

    Full Text Available Electrospinning is a method in which materials in solution are formed into nano- and micro-sized continuous fibers. Recent interest in this technique stems from both the topical nature of nanoscale material fabrication and the considerable potential for use of these nanoscale fibres in a range of applications including, amongst others, a range of biomedical applications processes such as drug delivery and the use of scaffolds to provide a framework for tissue regeneration in both soft and hard tissue applications systems. The objectives of this review are to describe the theory behind the technique, examine the effect of changing the process parameters on fiber morphology, and discuss the application and impact of electrospinning on the fields of vascular, neural, bone, cartilage, and tendon/ligament tissue engineering.

  3. [Changes in muscle tissue in hypothyroidism].

    Science.gov (United States)

    Jiskra, J

    2001-09-01

    This article offers a synopsis of detailed analysis of the functional and structural changes in muscle tissue in manifest and subclinical hypothyroidism. There is a brief overview of the division between mypathy and myositis, with emphasis on endocrinological and metabolic disorders. The necessity of endocrinological examination in each case of myopathy the etiology of which is indefinite is stressed, and this especially before the instigation of non-specific immunosuppressive treatment (e.g., corticosteroids) as this treatment has the risk of undesirable side-effects. In conclusion, it emphasises the negative influence of the nexus of hypothyroidism and the administering of a hypolipidemic in tandem on muscle tissue, as in rare cases this can lead to the disintegration of muscle tissue, i.e., rhabdomyolysis. The administering of hypolipidemic drugs to patients with hypothyroidism is indicated only in those cases where persists hyperlipoproteinemia after the normalisation of the thyroid function by substitutional treatment.

  4. Angiographic picture of soft tissue desmoid fibromas

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  5. Tissue Harmonic Synthetic Aperture Ultrasound Imaging

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Rasmussen, Joachim; Jensen, Jørgen Arendt

    2014-01-01

    Synthetic aperture sequential beamforming (SASB) and tissue har- monic imaging (THI) are combined to improve the image quality of medical ultrasound imaging. The technique is evaluated in a compar- ative study against dynamic receive focusing (DRF). The objective is to investigate if SASB combined...... with THI improves the image qual- ity compared to DRF-THI. The major benet of SASB is a reduced bandwidth between the probe and processing unit. A BK Medical 2202 Ultraview ultrasound scanner was used to acquire beamformed RF data for oine evaluation. The acquisition was made interleaved between methods......, and data were recorded with and without pulse inversion for tissue harmonic imaging. Data were acquired using a Sound Technol- ogy 192 element convex array transducer from both a wire phantom and a tissue mimicking phantom to investigate spatial resolution and pen- etration. In-vivo scans were also...

  6. Damage Models for Soft Tissues: A Survey.

    Science.gov (United States)

    Li, Wenguang

    Damage to soft tissues in the human body has been investigated for applications in healthcare, sports, and biomedical engineering. This paper reviews and classifies damage models for soft tissues to summarize achievements, identify new directions, and facilitate finite element analysis. The main ideas of damage modeling methods are illustrated and interpreted. A few key issues related to damage models, such as experimental data curve-fitting, computational effort, connection between damage and fractures/cracks, damage model applications, and fracture/crack extension simulation, are discussed. Several new challenges in the field are identified and outlined. This review can be useful for developing more advanced damage models and extending damage modeling methods to a variety of soft tissues.

  7. Primary Kaposi sarcoma of the subcutaneous tissue

    Directory of Open Access Journals (Sweden)

    Dezube Bruce J

    2008-09-01

    Full Text Available Abstract Background Involvement of the subcutis by Kaposi sarcoma (KS occurs primarily when cutaneous KS lesions evolve into deep penetrating nodular tumors. Primary KS of the subcutaneous tissue is an exceptional manifestation of this low-grade vascular neoplasm. Case presentation We present a unique case of acquired immune deficiency syndrome (AIDS-associated KS manifesting primarily in the subcutaneous tissue of the anterior thigh in a 43-year-old male, which occurred without overlying visible skin changes or concomitant KS disease elsewhere. Radiological imaging and tissue biopsy confirmed the diagnosis of KS. Conclusion This is the first documented case of primary subcutaneous KS occurring in the setting of AIDS. The differential diagnosis of an isolated subcutaneous lesion in an human immunodeficiency virus (HIV-infected individual is broad, and requires both imaging and a histopathological diagnosis to guide appropriate therapy.

  8. Subcutaneous tissue flaps for hallux covering.

    Science.gov (United States)

    Vaienti, Luca; Urzola, Victor; Scotti, Andrea; Masetto, L

    2010-03-01

    With the understanding of the extensive vascular supply of the subcutaneous tissue, of its efficacy in the protection of the anatomical structures and of its capability of promoting the adequate functioning of very stressed regions of the human body, the use of subcutaneous adipose flaps has become a valid and sometimes the only reasonable therapeutic weapon in the treatment of small and medium-sized tissue loss. Such a defect represents a common complication of great toe injuries and surgery. Here subcutaneous flap reconstruction is proposed for the treatment of dorsal and medial soft tissue losses of the hallux complicated with infection. Two case are reported. To the best of the authors' knowledge, this application has not been reported in this anatomical site so far. The technique might be worth knowing both for orthopedic and plastic surgeons, as it may represent a safe, less invasive solution for most tegumentary problems of the dorso-medial side of the first ray.

  9. Soft-tissue mineralization in Werner syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Leone, Antonio; Costantini, Alessandro Maria; Brigida, Raffaela; Antoniol, Onorina Monica; Bonomo, Lorenzo [Universita Cattolica School of Medicine, Department of Radiology, Rome (Italy); Antonelli-Incalzi, Raffaele [Universita Cattolica School of Medicine, Department of Geriatrics, Rome (Italy)

    2005-01-01

    Werner syndrome is a rare autosomal recessive disorder characterized by clinical signs of premature aging, short stature, scleroderma-like skin changes, endocrine abnormalities, cataracts, and an increased incidence of malignancies. We report on a 48-year-old woman with Werner syndrome associated with intracranial meningiomas who had extensive musculoskeletal manifestations including osteoporosis of the extremities, extensive tendinopathy about the ankles, osteomyelitis of the phalanges of the first left toe, abundant soft-tissue calcification, and two dense ossified soft-tissue masses, with cortical bone and trabeculae arising from the posterosuperior aspect of the calcanei and extending into Kager fat pads. A review of previous descriptions of the radiological abnormalities of Werner syndrome indicates that the presence of soft-tissue calcifications has either not been noted or been mentioned only briefly. Moreover, there is no mention of bony masses associated with Werner syndrome in the world literature, and this would appear to be the first report of this kind. (orig.)

  10. Mechanically driven interface propagation in biological tissues

    International Nuclear Information System (INIS)

    Ranft, Jonas; Joanny, Jean-François; Aliee, Maryam; Jülicher, Frank; Prost, Jacques

    2014-01-01

    Many biological tissues consist of more than one cell type. We study the dynamics of an interface between two different cell populations as it occurs during the growth of a tumor in a healthy host tissue. Recent work suggests that the rates of cell division and cell death are under mechanical control, characterized by a homeostatic pressure. The difference in the homeostatic pressures of two cell types drives the propagation of the interface, corresponding to the invasion of one cell type into the other. We derive a front propagation equation that takes into account the coupling between cell number balance and tissue mechanics. We show that in addition to pulled fronts, pushed-front solutions occur as a result of convection driven by mechanics. (paper)

  11. Transplantation of frozen-thawed ovarian tissue

    DEFF Research Database (Denmark)

    Gellert, S E; Pors, S E; Kristensen, Stine Gry

    2018-01-01

    . CONCLUSION: This study found no indications of sufficient numbers of malignant cells present in the ovarian tissue to cause recurrence of cancer after OTT. Further, it is unlikely that OTC affects the well-being of children born. OTC is now an established method of fertility preservation in Denmark......PURPOSE: The purpose of the study is to review all peer-reviewed published reports of women receiving ovarian tissue transplantation (OTT) with frozen/thawed tissue (OTC) with respect to age, diagnosis, transplantation site, fertility outcome, and potential side effects, including data from all...... women in the Danish program. METHODS: A systematic review of the literature was performed in PubMed combined with results from all patients who had received OTT in Denmark up to December 2017. RESULTS: OTT has been reported from 21 different countries comprising a total of 360 OTT procedures in 318...

  12. Controlled drug release for tissue engineering.

    Science.gov (United States)

    Rambhia, Kunal J; Ma, Peter X

    2015-12-10

    Tissue engineering is often referred to as a three-pronged discipline, with each prong corresponding to 1) a 3D material matrix (scaffold), 2) drugs that act on molecular signaling, and 3) regenerative living cells. Herein we focus on reviewing advances in controlled release of drugs from tissue engineering platforms. This review addresses advances in hydrogels and porous scaffolds that are synthesized from natural materials and synthetic polymers for the purposes of controlled release in tissue engineering. We pay special attention to efforts to reduce the burst release effect and to provide sustained and long-term release. Finally, novel approaches to controlled release are described, including devices that allow for pulsatile and sequential delivery. In addition to recent advances, limitations of current approaches and areas of further research are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Tissue Engineering in Regenerative Dental Therapy

    Directory of Open Access Journals (Sweden)

    Hiral Jhaveri-Desai

    2011-01-01

    Full Text Available Tissue engineering is amongst the latest exciting technologies having impacted the field of dentistry. Initially considered as a futuristic approach, tissue engineering is now being successfully applied in regenerative surgery. This article reviews the important determinants of tissue engineering and how they contribute to the improvement of wound healing and surgical outcomes in the oral region. Furthermore, we shall address the clinical applications of engineering involving oral and maxillofacial surgical and periodontal procedures along with other concepts that are still in experimental phase of development. This knowledge will aid the surgical and engineering researchers to comprehend the collaboration between these fields leading to extounding dental applications and to ever-continuing man-made miracles in the field of human science.

  14. Necrotising soft tissue infection following mastectomy

    Directory of Open Access Journals (Sweden)

    Jackson P

    2010-03-01

    Full Text Available Necrotising fasciitis is a rare but rapidly progressive soft tissue disease which can lead to extensive necrosis, systemic sepsis and death. Including this case, only 7 other cases have been reported in the world literature with only 2 others affecting the patient post mastectomy.This 59 year old Caucasian lady presented with severe soft tissue infection soon after mastectomy, which was successfully treated with a combination of debridement, triangulation, VAC© dressing and skin grafting.Necrotising soft tissue infections following mastectomy are rapidly progressive and potentially extremely serious. It is essential that a high index of clinical suspicion is maintained together with prompt aggressive treatment in a multidisciplinary environment to prevent worsening physical and psychological sequelae.

  15. Biomimetic electrospun nanofibers for tissue regeneration

    International Nuclear Information System (INIS)

    Liao, Susan; Li Bojun; Ma Zuwei; Wei He; Chan Casey; Ramakrishna, Seeram

    2006-01-01

    Nanofibers exist widely in human tissue with different patterns. Electrospinning nanotechnology has recently gained a new impetus due to the introduction of the concept of biomimetic nanofibers for tissue regeneration. The advanced electrospinning technique is a promising method to fabricate a controllable continuous nanofiber scaffold similar to the natural extracellular matrix. Thus, the biomedical field has become a significant possible application field of electrospun fibers. Although electrospinning has developed rapidly over the past few years, electrospun nanofibers are still at a premature research stage. Further comprehensive and deep studies on electrospun nanofibers are essential for promoting their biomedical applications. Current electrospun fiber materials include natural polymers, synthetic polymers and inorganic substances. This review briefly describes several typically electrospun nanofiber materials or composites that have great potential for tissue regeneration, and describes their fabrication, advantages, drawbacks and future prospects. (topical review)

  16. Fabrication of myogenic engineered tissue constructs.

    Science.gov (United States)

    Pacak, Christina A; Cowan, Douglas B

    2009-05-01

    Despite the fact that electronic pacemakers are life-saving medical devices, their long-term performance in pediatric patients can be problematic owing to the restrictions imposed by a child's small size and their inevitable growth. Consequently, there is a genuine need for innovative therapies designed specifically for pediatric patients with cardiac rhythm disorders. We propose that a conductive biological alternative consisting of a collagen-based matrix containing autologously-derived cells could better adapt to growth, reduce the need for recurrent surgeries, and greatly improve the quality of life for these patients. In the present study, we describe a procedure for incorporating primary skeletal myoblast cell cultures within a hydrogel matrix to fashion a surgically-implantable tissue construct that will serve as an electrical conduit between the upper and lower chambers of the heart. Ultimately, we anticipate using this type of engineered tissue to restore atrioventricular electrical conduction in children with complete heart block. In view of that, we isolate myoblasts from the skeletal muscles of neonatal Lewis rats and plate them onto laminin-coated tissue culture dishes using a modified version of established protocols. After one to two days, cultured cells are collected and mixed with antibiotics, type 1 collagen, Matrigel, and NaHCO(3). The result is a viscous, uniform solution that can be cast into a mold of nearly any shape and size. For our tissue constructs, we employ type 1 collagen isolated from fetal lamb skin using standard procedures. Once the tissue has solidified at 37 degrees C, culture media is carefully added to the plate until the construct is submerged. The engineered tissue is then allowed to further condense through dehydration for 2 more days, at which point it is ready for in vitro assessment or surgical-implantation.

  17. Tissue engineering of ligaments for reconstructive surgery.

    Science.gov (United States)

    Hogan, MaCalus V; Kawakami, Yohei; Murawski, Christopher D; Fu, Freddie H

    2015-05-01

    The use of musculoskeletal bioengineering and regenerative medicine applications in orthopaedic surgery has continued to evolve. The aim of this systematic review was to address tissue-engineering strategies for knee ligament reconstruction. A systematic review of PubMed/Medline using the terms "knee AND ligament" AND "tissue engineering" OR "regenerative medicine" was performed. Two authors performed the search, independently assessed the studies for inclusion, and extracted the data for inclusion in the review. Both preclinical and clinical studies were reviewed, and the articles deemed most relevant were included in this article to provide relevant basic science and recent clinical translational knowledge concerning "tissue-engineering" strategies currently used in knee ligament reconstruction. A total of 224 articles were reviewed in our initial PubMed search. Non-English-language studies were excluded. Clinical and preclinical studies were identified, and those with a focus on knee ligament tissue-engineering strategies including stem cell-based therapies, growth factor administration, hybrid biomaterial, and scaffold development, as well as mechanical stimulation modalities, were reviewed. The body of knowledge surrounding tissue-engineering strategies for ligament reconstruction continues to expand. Presently, various tissue-engineering techniques have some potential advantages, including faster recovery, better ligamentization, and possibly, a reduction of recurrence. Preclinical research of these novel therapies continues to provide promising results. There remains a need for well-designed, high-powered comparative clinical studies to serve as a foundation for successful translation into the clinical setting going forward. Level IV, systematic review of Level IV studies. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  18. Accumulation of ethoxyquin in the tissue

    International Nuclear Information System (INIS)

    Kim, H.L.

    1991-01-01

    Ethoxyquin (EQ) residue levels in the mouse tissue were determined by the HPLC-fluorometric detection method. Mice were given powdered feed containing 0, 0.125, and 0.5% EQ HCl and the EQ residue levels in liver, kidney, lung, and brain tissues were determined after 2, 4, 6, 10, and 14 wk (4 mice/group). The tissue samples were homogenized in 10 volumes (w/v) of acetonitrile-water (7:3, v/v), centrifuged, and the supernatants were stored in a freezer for 2-3 h or until the two layers separated; then the clear upper layers were analyzed. The mean EQ residue levels in the tissue ranged 0.84-4.58 micrograms EQ/g liver and 0.11-0.92 micrograms EQ/g brain. The relative weight of the liver (5.21-7.07% body weight) and the hepatic glutathione level (5.99-7.83 microM GSH/g tissue) of mice that received EQ were significantly higher than those of the controls (4.67-5.05% body weight and 4.30-5.78 microM GSH/g tissue, respectively). The mean hepatic mitochondrial glutathione level of the higher EQ feeding group, following dietary administration of EQ for 14 wk, was approximately twofold (1.68 nM GSH/mg protein) of both the control and the lower EQ feeding groups (0.83 and 0.74 nM GSH/mg protein, respectively)

  19. Mechanisms of lymphatic regeneration after tissue transfer.

    Directory of Open Access Journals (Sweden)

    Alan Yan

    2011-02-01

    Full Text Available Lymphedema is the chronic swelling of an extremity that occurs commonly after lymph node resection for cancer treatment. Recent studies have demonstrated that transfer of healthy tissues can be used as a means of bypassing damaged lymphatics and ameliorating lymphedema. The purpose of these studies was to investigate the mechanisms that regulate lymphatic regeneration after tissue transfer.Nude mice (recipients underwent 2-mm tail skin excisions that were either left open or repaired with full-thickness skin grafts harvested from donor transgenic mice that expressed green fluorescent protein in all tissues or from LYVE-1 knockout mice. Lymphatic regeneration, expression of VEGF-C, macrophage infiltration, and potential for skin grafting to bypass damaged lymphatics were assessed.Skin grafts healed rapidly and restored lymphatic flow. Lymphatic regeneration occurred beginning at the peripheral edges of the graft, primarily from ingrowth of new lymphatic vessels originating from the recipient mouse. In addition, donor lymphatic vessels appeared to spontaneously re-anastomose with recipient vessels. Patterns of VEGF-C expression and macrophage infiltration were temporally and spatially associated with lymphatic regeneration. When compared to mice treated with excision only, there was a 4-fold decrease in tail volumes, 2.5-fold increase in lymphatic transport by lymphoscintigraphy, 40% decrease in dermal thickness, and 54% decrease in scar index in skin-grafted animals, indicating that tissue transfer could bypass damaged lymphatics and promote rapid lymphatic regeneration.Our studies suggest that lymphatic regeneration after tissue transfer occurs by ingrowth of lymphatic vessels and spontaneous re-connection of existing lymphatics. This process is temporally and spatially associated with VEGF-C expression and macrophage infiltration. Finally, tissue transfer can be used to bypass damaged lymphatics and promote rapid lymphatic regeneration.

  20. An optimal control problem by controlling heat source of the surface of tissue

    OpenAIRE

    Dhar, 1Rikhiya; Dhar, Ranajit; Dhar, Piyanka

    2013-01-01

    A distributed optimal control problem for a system described by bio-heat equation for a homogeneous plane tissue is analytically investigated such that a desired temperature of the tissue at a particular point of location of tumour in hyperthermia can be attained at the end of a total time of operation of the process due to induced microwave on the surface of the tissue which is taken as control. Here the temperature of the tissue along the length of the tissue at different times of operation...