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Sample records for transcutaneous oxygen tension

  1. Transcutaneous oxygen tension in imminent foot gangrene

    DEFF Research Database (Denmark)

    Tønnesen, K H

    1978-01-01

    Transcutaneous oxygen tension at 44 degree C and maximal isotope clearance (90m Tc-pretechnetate + histramine) just proximal to the 1st toe and systolic toe blood pressure (strain gauge) were studied on a tilt table in patients with various degrees of obstructive arteriosclerotic disease. In legs...

  2. Changes in transcutaneous oxygen tension during exercise in pulmonary emphysema.

    OpenAIRE

    Hughes, J A; Gray, B J; Hutchison, D C

    1984-01-01

    Continuous measurements of transcutaneous oxygen tension (tcPO2) were made in 23 patients with radiological evidence of emphysema, at rest and during a maximal progressive exercise test. tcPO2 during the final phase of exercise was compared with tcPO2 at rest; the mean change (exercising minus resting value) in tcPO2 (delta tcPO2) was -0.8 mm Hg (SD 10.5, range -18 to +25) (-0.1 kPa (SD 1.4, range -2.4 to +3.3]. delta tcPO2 was correlated with: resting arterial oxygen tension (PaO2) (r = 0.60...

  3. Superiority of Transcutaneous Oxygen Tension Measurements in Predicting Limb Salvage After Below-the-Knee Angioplasty: A Prospective Trial in Diabetic Patients With Critical Limb Ischemia

    International Nuclear Information System (INIS)

    Redlich, Ulf; Xiong, Yan Y.; Pech, Maciej; Tautenhahn, Jörg; Halloul, Zuhir; Lobmann, Ralf; Adolf, Daniela; Ricke, Jens; Dudeck, Oliver

    2011-01-01

    Purpose: To assess postprocedural angiograms, the ankle–brachial index (ABI), and transcutaneous oxygen tension (TcPO 2 ) to predict outcome after infrageniculate angioplasty (PTA) in diabetic patients with critical limb ischemia (CLI) scheduled for amputation. Materials and Methods: PTA was performed in 28 diabetic patients with CLI confined to infrapopliteal vessels. We recorded patency of crural vessels, including the vascular supply of the foot as well as the ABI and TcPO 2 of the foot. Results: Technical success rate was 92.9% (n = 26), and limb-salvage rate at 12 months was 60.7% (n = 17). The number of patent straight vessels above and below the level of the malleoli increased significantly in patients avoiding amputation. Amputation was unnecessary in 88.2% (n = 15) patients when patency of at least one tibial artery was achieved. In 72.7% (n = 8) of patients, patency of the peroneal artery alone was not sufficient for limb salvage. ABI was of no predictive value for limb salvage. TcPO 2 values increased significantly only in patients not requiring amputation (P = 0.015). In patients with only one tibial artery supplying the foot or only a patent peroneal artery in postprocedural angiograms, TcPO 2 was capable of reliably predicting the outcome. Conclusion: Below-the-knee PTA as an isolated part of therapy was effective to prevent major amputation in more than a half of diabetic patients with CLI. TcPO 2 was a valid predictor for limb salvage, even when angiographic outcome criteria failed.

  4. Effects of the transcutaneous electrode temperature on the accuracy of transcutaneous carbon dioxide tension

    DEFF Research Database (Denmark)

    Sørensen, Line C; Brage-Andersen, Lene; Greisen, Gorm

    2011-01-01

    The harmful effect of hypocapnia on the neonatal brain emphasizes the importance of monitoring arterial carbon dioxide tension (PaCO2). Transcutaneous monitoring of carbon dioxide (tcPCO2) reduces the need for arterial blood sampling. Drawbacks are high electrode temperature causing risks of skin...

  5. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    la Cour, M; Kiilgaard, Jens Folke; Eysteinsson, T

    2000-01-01

    To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide.......To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide....

  6. Effects of the transcutaneous electrode temperature on the accuracy of transcutaneous carbon dioxide tension

    DEFF Research Database (Denmark)

    Sørensen, Line C; Brage-Andersen, Lene; Greisen, Gorm

    2011-01-01

    The harmful effect of hypocapnia on the neonatal brain emphasizes the importance of monitoring arterial carbon dioxide tension (PaCO2). Transcutaneous monitoring of carbon dioxide (tcPCO2) reduces the need for arterial blood sampling. Drawbacks are high electrode temperature causing risks of skin...... burning. The aim was to determine the accuracy and precision of tcPCO2 at reduced electrode temperature....

  7. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    Kiilgaard, Jens Folke; Pedersen, D B; Eysteinsson, T

    2004-01-01

    The authors have previously reported that carbonic anhydrase inhibitors such as acetazolamide and dorzolamide raise optic nerve oxygen tension (ONPO(2)) in pigs. The purpose of the present study was to investigate whether timolol, which belongs to another group of glaucoma drugs called beta...

  8. Biomedical sensor for transcutaneous oxygen measurements using thick film technology

    OpenAIRE

    Lam, Yu-Zhi (Liza)

    2003-01-01

    The measurement of the partial pressure of oxygen in arterial blood is essential for the analysis of a patient's respiratory condition. There are several commercially available methods and systems to measure this parameter transcutaneously. However, they tend to be cumbersome and costly. To overcome the disadvantages presented, a new type of sensor for transcutaneous blood gas measurement was investigated, employing thick film technology, which is an excellent technique to produce sensors in ...

  9. Mitochondrial Respiration and Oxygen Tension.

    Science.gov (United States)

    Shaw, Daniel S; Meitha, Karlia; Considine, Michael J; Foyer, Christine H

    2017-01-01

    Measurements of respiration and oxygen tension in plant organs allow a precise understanding of mitochondrial capacity and function within the context of cellular oxygen metabolism. Here we describe methods that can be routinely used for the isolation of intact mitochondria, and the determination of respiratory electron transport, together with techniques for in vivo determination of oxygen tension and measurement of respiration by both CO 2 production and O 2 consumption that enables calculation of the respiratory quotient [CO 2 ]/[O 2 ].

  10. Use of a combined oxygen and carbon dioxide transcutaneous electrode in the estimation of gas exchange during exercise.

    OpenAIRE

    Sridhar, M K; Carter, R; Moran, F; Banham, S W

    1993-01-01

    BACKGROUND--Accurate and reliable measurement of gas exchange during exercise has traditionally involved arterial cannulation. Non-invasive devices to estimate arterial oxygen (O2) and carbon dioxide (CO2) tensions are now available. A method has been devised and evaluated for measuring gas exchange during exercise with a combined transcutaneous O2 and CO2 electrode. METHODS--Symptom limited exercise tests were carried out in 24 patients reporting effort intolerance and breathlessness. Exerci...

  11. The newborn oxygram: automated processing of transcutaneous oxygen data.

    Science.gov (United States)

    Horbar, J D; Clark, J T; Lucey, J F

    1980-12-01

    Hypoxemic and hyperoxemic episodes are common in newborns with respiratory disorders. We have developed a microprocessor-based data system for use with transcutaneous oxygen (TcPO2) monitors in an attempt to quantitate these episodes. The amount of time spent by an infant in each of ten preset TcPO2 ranges can be automatically recorded. These data are referred to as the oxygram. Fourteen newborn infants were monitored for a total of 552 hours using this system. They spent a mean of 2.96% of the time with a TcPO2 less than or equal to 40 torr and 0.26% of the time with a TcPO2 greater than 100 torr. Representative oxygrams are presented. Clinical and research applications of the data system are discussed.

  12. Multibreath alveolar oxygen tension imaging.

    Science.gov (United States)

    Clapp, Justin; Hamedani, Hooman; Kadlecek, Stephen; Xin, Yi; Shaghaghi, Hoora; Siddiqui, Sarmad; Rossman, Milton D; Rizi, Rahim R

    2016-10-01

    This study tested the ability of a multibreath hyperpolarized HP (3) He MRI protocol to increase the accuracy of regional alveolar oxygen tension (PA O2 ) measurements by lessening the influence of gas-flow artifacts. Conventional single-breath PA O2 measurement has been susceptible to error induced by intervoxel gas flow, particularly when used to study subjects with moderate-to-severe chronic obstructive pulmonary disease (COPD). Both single-breath and multibreath PA O2 imaging schemes were implemented in seven human subjects (one healthy, three asymptomatic smokers, and three COPD). The number and location of voxels with nonphysiologic PA O2 values generated by intervoxel gas flow were compared between the two protocols. The multibreath scheme resulted in a significantly lower total percentage of nonphysiologic PA O2 values (6.0%) than the single-breath scheme (13.7%) (P = 0.006). PA O2 maps showed several patterns of gas-flow artifacts that were present in the single-breath protocol but mitigated by the multibreath approach. Multibreath imaging also allowed for the analysis of slow-filling areas that presented no signal after a single breath. A multibreath approach enhances the accuracy and completeness of noninvasive PA O2 measurement by significantly lessening the proportion of nonphysiologic values generated by intervoxel gas flow. Magn Reson Med 76:1092-1101, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  13. Oxygen tension level and human viral infections

    Energy Technology Data Exchange (ETDEWEB)

    Morinet, Frédéric, E-mail: frederic.morinet@sls.aphp.fr [Centre des Innovations Thérapeutiques en Oncologie et Hématologie (CITOH), CHU Saint-Louis, Paris (France); Université Denis Diderot, Sorbonne Paris Cité Paris, Paris (France); Casetti, Luana [Institut Cochin INSERM U1016, Paris (France); François, Jean-Hugues; Capron, Claude [Institut Cochin INSERM U1016, Paris (France); Laboratoire d' Hématologie, Hôpital Ambroise Paré, Boulogne (France); Université de Versailles Saint-Quentin en Yvelynes, Versailles (France); Pillet, Sylvie [Laboratoire de Bactériologie-Virologie-Hygiène, CHU de Saint-Etienne, Saint-Etienne (France); Université de Lyon et Université de Saint-Etienne, Jean Monnet, GIMAP EA3064, F-42023 Saint-Etienne, Lyon (France)

    2013-09-15

    The role of oxygen tension level is a well-known phenomenon that has been studied in oncology and radiotherapy since about 60 years. Oxygen tension may inhibit or stimulate propagation of viruses in vitro as well as in vivo. In turn modulating oxygen metabolism may constitute a novel approach to treat viral infections as an adjuvant therapy. The major transcription factor which regulates oxygen tension level is hypoxia-inducible factor-1 alpha (HIF-1α). Down-regulating the expression of HIF-1α is a possible method in the treatment of chronic viral infection such as human immunodeficiency virus infection, chronic hepatitis B and C viral infections and Kaposi sarcoma in addition to classic chemotherapy. The aim of this review is to supply an updating concerning the influence of oxygen tension level in human viral infections and to evoke possible new therapeutic strategies regarding this environmental condition. - Highlights: • Oxygen tension level regulates viral replication in vitro and possibly in vivo. • Hypoxia-inducible factor 1 (HIF-1α) is the principal factor involved in Oxygen tension level. • HIF-1α upregulates gene expression for example of HIV, JC and Kaposi sarcoma viruses. • In addition to classical chemotherapy inhibition of HIF-1α may constitute a new track to treat human viral infections.

  14. Reduction of skin damage from transcutaneous oxygen electrodes using a spray on dressing.

    Science.gov (United States)

    Evans, N J; Rutter, N

    1986-09-01

    A spray on, copolymer acrylic dressing (Op-Site) was used to limit the skin damage caused by a transcutaneous oxygen electrode and its adhesive ring. Two identical electrodes were applied to the abdominal skin of 10 preterm infants, one on untreated skin, the other after application of Op-Site. It was found that Op-Site prevented the epidermal damage (as measured by transepidermal water loss) that occurs when the adhesive ring is removed from untreated skin. It did not interfere with transcutaneous oxygen measurements; absolute values and response times were unchanged. Op-Site is therefore useful in preventing the skin trauma that occurs when transcutaneous oxygen monitoring is being performed in preterm infants below 30 weeks' gestation in the first week of life. Care must be taken, however, to prevent a build up of Op-Site--it should be applied as a single layer, allowed to dry, and removed after use.

  15. TRANSCUTANEOUS ELECTRICAL NERVE-STIMULATION (TENS) IN RAYNAUDS-PHENOMENON

    NARCIS (Netherlands)

    MULDER, P; DOMPELING, EC; VANSLOCHTERENVANDERBOOR, JC; KUIPERS, WD; SMIT, AJ

    Transcutaneous nerve stimulation (TENS) has been described as resulting in vasodilatation. The effect of 2 Hz TENS of the right hand during forty-five minutes on skin temperature and plethysmography of the third digit of both hands and feet and on transcutaneous oxygen tension (TcpO2) of the right

  16. Effect of Electroacupuncture on Transcutaneous Oxygen Partial Pressure During Hyperbaric Oxygen Therapy in Healthy Individuals.

    Science.gov (United States)

    Qu, Lan; Ye, Yong; Li, Chunfeng; Gao, Guangkai

    2015-01-01

    The goal of hyperbaric oxygen therapy (HBOT) is to increase the oxygen (O₂) supply to the body significantly. Because of the toxic side effects and complications of hyperbaric oxygen (HBO₂), the environmental pressure and treatment time must be restricted. The research team hypothesized that other therapies administered during HBOT could safely improve the value of the arterial oxygen partial pressure (PaO₂) during HBOT and improve its therapeutic effect. The study intended to investigate whether electroacupuncture (EA) while receiving HBOT had a greater effect for healthy individuals than HBOT or EA alone or EA combined with normobaric pure oxygen (pure O₂). The research team designed a randomized, controlled trial. The study was performed in the Department of Hyperbaric Medicine at the No. 401 Hospital of the People's Liberation Army in Qingdao, China. A total of 81 volunteers were recruited. After thorough physical examination and laboratory testing, 21 volunteers were excluded from the study. Participants included 60 healthy volunteers. Participants were randomly assigned to 1 of 4 groups of 15 participants each: (1) an HBOT group, (2) an EA group, (3) an EA During HBOT group, and (4) an EA Combined With Pure O₂group. Because at the current technology level a blood gas analyzer cannot test PaO₂during HBOT, transcutaneous oxygen partial pressure (PtcO₂) of the participants was tested instead. Before, during, and after EA, variations in PtcO₂were monitored in each group. For the EA During HBOT group, (1) the increase in PtcO₂during EA was significantly greater than that observed for the other 3 groups (P > .05). The EA During HBOT method provided improvements in the efficacy, safety, and tolerability of HBOT, and the study's results partially demonstrated the accuracy of the research team's hypothesis that EA therapy applied during HBOT could safely improve the value of PtcO₂(PaO₂) during HBOT and produce a greater therapeutic effect.

  17. Dorzolamide increases retinal oxygen tension after branch retinal vein occlusion

    DEFF Research Database (Denmark)

    Noergaard, Michael Hove; Bach-Holm, Daniella; Scherfig, Erik

    2008-01-01

    To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs.......To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs....

  18. Reduction of skin damage from transcutaneous oxygen electrodes using a spray on dressing.

    OpenAIRE

    Evans, N J; Rutter, N

    1986-01-01

    A spray on, copolymer acrylic dressing (Op-Site) was used to limit the skin damage caused by a transcutaneous oxygen electrode and its adhesive ring. Two identical electrodes were applied to the abdominal skin of 10 preterm infants, one on untreated skin, the other after application of Op-Site. It was found that Op-Site prevented the epidermal damage (as measured by transepidermal water loss) that occurs when the adhesive ring is removed from untreated skin. It did not interfere with transcut...

  19. Reproducibility of proximal and distal transcutaneous oxygen pressure measurements during exercise in stage 2 arterial claudication.

    Science.gov (United States)

    Bouyé, P; Picquet, J; Jaquinandi, V; Enon, B; Leftheriotis, G; Saumet, J-L; Abraham, P

    2004-06-01

    Although transcutaneous oxygen pressure measurements (tcpO2) are largely used in the investigation of vascular patients, its reproducibility is still debated. Indeed an unpredictable gradient exists between arterial and transcutaneous oxygen pressure. We hypothesised that indices taking into account changes over time and independent of absolute starting values would be more reproducible than other indices. comparative test-retest procedure (1 to 13 days between tests). institutional practice, ambulatory care. 15 subjects with stage 2 claudication. tcpO2 recordings at rest and at exercise during the 2 treadmill tests. calculation of the Delta-from-rest of oxygen pressure index (limb tcpO2 changes minus chest tcpO2 changes), of the resting - or minimal values attained during exercise - of absolute tcpO2 and of the regional perfusion index (regional perfusion index: ration of limb to chest). Both absolute tcpO2 and regional perfusion index at rest showed low reproducibility. During exercise the best reproducibility was attained through Delta-from-rest of oxygen pressure index calculation. Equations from the linear regression analysis (test 2 versus test 1) were 0.88 x -4.2 (r(2)=0.82) at the buttock level and 0.82 x -3.8 (r(2)=0.80) at the calf level. TcpO2 measurement on the calf or buttock during exercise, is a reproducible measurement in patients with vascular claudication, specifically when corrected for exercise-induced systemic pO2 changes trough Delta-from-rest of oxygen pressure calculation.

  20. A microfluidic cell culture array with various oxygen tensions.

    Science.gov (United States)

    Peng, Chien-Chung; Liao, Wei-Hao; Chen, Ying-Hua; Wu, Chueh-Yu; Tung, Yi-Chung

    2013-08-21

    Oxygen tension plays an important role in regulating various cellular functions in both normal physiology and disease states. Therefore, drug testing using conventional in vitro cell models under normoxia often possesses limited prediction capability. A traditional method of setting an oxygen tension in a liquid medium is by saturating it with a gas mixture at the desired level of oxygen, which requires bulky gas cylinders, sophisticated control, and tedious interconnections. Moreover, only a single oxygen tension can be tested at the same time. In this paper, we develop a microfluidic cell culture array platform capable of performing cell culture and drug testing under various oxygen tensions simultaneously. The device is fabricated using an elastomeric material, polydimethylsiloxane (PDMS) and the well-developed multi-layer soft lithography (MSL) technique. The prototype device has 4 × 4 wells, arranged in the same dimensions as a conventional 96-well plate, for cell culture. The oxygen tensions are controlled by spatially confined oxygen scavenging chemical reactions underneath the wells using microfluidics. The platform takes advantage of microfluidic phenomena while exhibiting the combinatorial diversities achieved by microarrays. Importantly, the platform is compatible with existing cell incubators and high-throughput instruments (liquid handling systems and plate readers) for cost-effective setup and straightforward operation. Utilizing the developed platform, we successfully perform drug testing using an anti-cancer drug, triapazamine (TPZ), on adenocarcinomic human alveolar basal epithelial cell line (A549) under three oxygen tensions ranging from 1.4% to normoxia. The developed platform is promising to provide a more meaningful in vitro cell model for various biomedical applications while maintaining desired high throughput capabilities.

  1. Investigation of spatial resolution dependent variability in transcutaneous oxygen saturation using point spectroscopy system

    Science.gov (United States)

    Philimon, Sheena P.; Huong, Audrey K. C.; Ngu, Xavier T. I.

    2017-08-01

    This paper aims to investigate the variation in one’s percent mean transcutaneous oxygen saturation (StO2) with differences in spatial resolution of data. This work required the knowledge of extinction coefficient of hemoglobin derivatives in the wavelength range of 520 - 600 nm to solve for the StO2 value via an iterative fitting procedure. A pilot study was conducted on three healthy subjects with spectroscopic data collected from their right index finger at different arbitrarily selected distances. The StO2 value estimated by Extended Modified Lambert Beer (EMLB) model revealed a higher mean StO2 of 91.1 ± 1.3% at a proximity distance of 30 mm compared to 60.83 ± 2.8% at 200 mm. The results showed a high correlation between data spatial resolution and StO2 value, and revealed a decrease in StO2 value as the sampling distance increased. The preliminary findings from this study contribute to the knowledge of the appropriate distance range for consistent and high repeatability measurement of skin oxygenation.

  2. "Tissue oxygen tension, a determinant of resistance to infection and ...

    African Journals Online (AJOL)

    "Tissue oxygen tension, a determinant of resistance to infection and healing" - An Inaugural Lecture. K Jönsson. Abstract. An Inaugural Lecture Given in the University of Zimbabwe on 21 June 2001. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  3. Oxygen Tension Regulates Human Mesenchymal Stem Cell Paracrine Functions

    OpenAIRE

    Paquet, Joseph; Deschepper, Mickael; Moya, Adrien; Logeart-Avramoglou, Delphine; Boisson-Vidal, Catherine; Petite, Hervé

    2015-01-01

    This study examined the shift of the human mesenchymal stem cell (hMSC) cytokine signature induced by oxygen tension. Conditioned media obtained from hMSCs cultured under near anoxia exhibited significantly enhanced chemotactic and proangiogenic properties and a significant decrease in the inflammatory mediator content. These results elucidate important aspects of using MSCs in regenerative medicine, contribute to improving the efficacy of such therapies, and highlight the interest in using c...

  4. Hemodynamic parameters change earlier than tissue oxygen tension in hemorrhage.

    Science.gov (United States)

    Pestel, Gunther J; Fukui, Kimiko; Kimberger, Oliver; Hager, Helmut; Kurz, Andrea; Hiltebrand, Luzius B

    2010-05-15

    Untreated hypovolemia results in impaired outcome. This study tests our hypothesis whether general hemodynamic parameters detect acute blood loss earlier than monitoring parameters of regional tissue beds. Eight pigs (23-25 kg) were anesthetized and mechanically ventilated. A pulmonary artery catheter and an arterial catheter were inserted. Tissue oxygen tension was measured with Clark-type electrodes in the jejunal and colonic wall, in the liver, and subcutaneously. Jejunal microcirculation was assessed by laser Doppler flowmetry (LDF). Intravascular volume was optimized using difference in pulse pressure (dPP) to keep dPP below 13%. Sixty minutes after preparation, baseline measurements were taken. At first, 5% of total blood volume was withdrawn, followed by another 5% increment, and then in 10% increments until death. After withdrawal of 5% of estimated blood volume, dPP increased from 6.1% +/- 3.0% to 20.8% +/- 2.7% (P < 0.01). Mean arterial pressure (MAP), mean pulmonary artery pressure (PAP) and pulmonary artery occlusion pressure (PAOP) decreased with a blood loss of 10% (P < 0.01). Cardiac output (CO) changed after a blood loss of 20% (P < 0.05). Tissue oxygen tension in central organs, and blood flow in the jejunal muscularis decreased (P < 0.05) after a blood loss of 20%. Tissue oxygen tension in the skin, and jejunal mucosa blood flow decreased (P < 0.05) after a blood loss of 40% and 50%, respectively. In this hemorrhagic pig model systemic hemodynamic parameters were more sensitive to detect acute hypovolemia than tissue oxygen tension measurements or jejunal LDF measurements. Acute blood loss was detected first by dPP. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  5. Renal transplantation induces mitochondrial uncoupling, increased kidney oxygen consumption, and decreased kidney oxygen tension

    NARCIS (Netherlands)

    Papazova, Diana A.; Friederich-Persson, Malou; Joles, Jaap A.; Verhaar, Marianne C.

    2015-01-01

    Hypoxia is an acknowledged pathway to renal injury and ischemia-reperfusion (I/R) and is known to reduce renal oxygen tension (PO2). We hypothesized that renal I/R increases oxidative damage and induces mitochondrial uncoupling, resulting in increased oxygen consumption and hence kidney

  6. Cerebral Microcirculation and Oxygen Tension in the Human Secondary Cortex

    Science.gov (United States)

    Linninger, A. A.; Gould, I. G.; Marinnan, T.; Hsu, C.-Y.; Chojecki, M.; Alaraj, A.

    2013-01-01

    The three-dimensional spatial arrangement of the cortical microcirculatory system is critical for understanding oxygen exchange between blood vessels and brain cells. A three-dimensional computer model of a 3 × 3 × 3 mm3 subsection of the human secondary cortex was constructed to quantify oxygen advection in the microcirculation, tissue oxygen perfusion, and consumption in the human cortex. This computer model accounts for all arterial, capillary and venous blood vessels of the cerebral microvascular bed as well as brain tissue occupying the extravascular space. Microvessels were assembled with optimization algorithms emulating angiogenic growth; a realistic capillary bed was built with space filling procedures. The extravascular tissue was modeled as a porous medium supplied with oxygen by advection–diffusion to match normal metabolic oxygen demand. The resulting synthetic computer generated network matches prior measured morphometrics and fractal patterns of the cortical microvasculature. This morphologically accurate, physiologically consistent, multi-scale computer network of the cerebral microcirculation predicts the oxygen exchange of cortical blood vessels with the surrounding gray matter. Oxygen tension subject to blood pressure and flow conditions were computed and validated for the blood as well as brain tissue. Oxygen gradients along arterioles, capillaries and veins agreed with in vivo trends observed recently in imaging studies within experimental tolerances and uncertainty. PMID:23842693

  7. Effect of pneumatic tourniquet on muscle oxygen tension.

    Science.gov (United States)

    Santavirta, S; Höckerstedt, K; Niinikoski, J

    1978-10-01

    Recent investigations suggest that circulation in a limb can be reduced with a tourniquet to less than 1 per cent of the control limb, or even completely occluded. The development of tissue oxygen tonometry with implanted silastic tubes has provided new possibilities for assessing muscle tissue oxygen tension. In the present work, this method was employed to register the effect of tourniquet blackade on the lower limb muscle PO2 in rabbits. The duration of the tourniquet blockade was 60, 120 and 180 minutes. The baseline muscle PO2 in the tibialis anterior muscle was 22.6 +/- 0.6 mmHg. During the tourniquet blockade the oxygen tension dropped to minimal values between 9.2 +/- 0.5 and 10.7 +/- 0.6 mmHg in these experimental groups, but the tissue microclimate never reached fully anoxic conditions. The rapid response of muscle PO2 to oxygen breathing after release of the blockade suggests that limb microcirculation tolerates tourniquet occlusion well.

  8. Oxygen tension during biofilm growth influences the efficacy antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Raquel Pippi ANTONIAZZI

    Full Text Available Abstract Objective To compare the antimicrobial efficacy of a 0.12% chlorhexidine (CHX and herbal green tea (Camellia sinensis solution on established biofilms formed at different oxygen tensions in an in situ model. Method Twenty-five dental students were eligible for the study. In situ devices with standardized enamel specimens (ES facing the palatal and buccal sides were inserted in the mouths of volunteers for a 7 day period. No agent was applied during the first four days. From the fifth day onward, both agents were applied to the test ES group and no agent was applied to the control ES group. After 7 days the ES fragments were removed from the devices, sonicated, plated on agar, and incubated for 24 h at 37 °C to determine and quantify the colony forming units (CFUs. Result CHX had significantly higher efficacy compared to green tea on the buccal (1330 vs. 2170 CFU/µL and palatal (2250 vs. 2520 CFU/µL ES. In addition, intragroup comparisons showed significantly higher efficacy in buccal ES over palatal ES (1330 vs. 2250 CFU/µL for CHX and 2170 vs, 2520 CFU/µL for CV for both solutions. Analysis of the ES controls showed significantly higher biofilm formation in palatal ES compared to buccal ES. Conclusion CHX has higher efficacy than green tea on 4-day biofilms. The efficacy of both agents was reduced for biofilms grown in a low oxygen tension environment. Therefore, the oxygen tension environment seems to influence the efficacy of the tested agents.

  9. Oxygen Tension Regulates Human Mesenchymal Stem Cell Paracrine Functions.

    Science.gov (United States)

    Paquet, Joseph; Deschepper, Mickael; Moya, Adrien; Logeart-Avramoglou, Delphine; Boisson-Vidal, Catherine; Petite, Hervé

    2015-07-01

    : Mesenchymal stem cells (MSCs) have captured the attention and research endeavors of the scientific world because of their differentiation potential. However, there is accumulating evidence suggesting that the beneficial effects of MSCs are predominantly due to the multitude of bioactive mediators secreted by these cells. Because the paracrine potential of MSCs is closely related to their microenvironment, the present study investigated and characterized select aspects of the human MSC (hMSC) secretome and assessed its in vitro and in vivo bioactivity as a function of oxygen tension, specifically near anoxia (0.1% O2) and hypoxia (5% O2), conditions that reflect the environment to which MSCs are exposed during MSC-based therapies in vivo. In contrast to supernatant conditioned media (CM) obtained from hMSCs cultured at either 5% or 21% of O2, CM from hMSCs cultured under near anoxia exhibited significantly (p mesenchymal stem cell (hMSC) secretome and assessed its in vitro and in vivo biological bioactivity as a function of oxygen tension, specifically near anoxia (0.1% O2) and hypoxia (5% O2), conditions that reflect the environment to which MSCs are exposed during MSC-based therapies in vivo. The present study provided the first evidence of a shift of the hMSC cytokine signature induced by oxygen tension, particularly near anoxia (0.1% O2). Conditioned media obtained from hMSCs cultured under near anoxia exhibited significantly enhanced chemotactic and proangiogenic properties and a significant decrease in the inflammatory mediator content. These findings provide new evidence that elucidates aspects of great importance for the use of MSCs in regenerative medicine, could contribute to improving the efficacy of such therapies, and most importantly highlighted the interest in using conditioned media in therapeutic modalities. ©AlphaMed Press.

  10. Effect of administration of water enriched in O2 by injection or electrolysis on transcutaneous oxygen pressure in anesthetized pigs.

    Science.gov (United States)

    Charton, Antoine; Péronnet, François; Doutreleau, Stephane; Lonsdorfer, Evelyne; Klein, Alexis; Jimenez, Liliana; Geny, Bernard; Diemunsch, Pierre; Richard, Ruddy

    2014-01-01

    Oral administration of oxygenated water has been shown to improve blood oxygenation and could be an alternate way for oxygen (O2) supply. In this experiment, tissue oxygenation was compared in anesthetized pigs receiving a placebo or water enriched in O2 by injection or a new electrolytic process. Forty-two pigs randomized in three groups received either mineral water as placebo or water enriched in O2 by injection or the electrolytic process (10 mL/kg in the stomach). Hemodynamic parameters, partial pressure of oxygen in the arterial blood (PaO2), skin blood flow, and tissue oxygenation (transcutaneous oxygen pressure, or TcPO2) were monitored during 90 minutes of general anesthesia. Absorption and tissue distribution of the three waters administered were assessed using dilution of deuterium oxide. Mean arterial pressure, heart rate, PaO2, arteriovenous oxygen difference, and water absorption from the gut were not significantly different among the three groups. The deuterium to protium ratio was also similar in the plasma, skin, and muscle at the end of the protocol. Skin blood flow decreased in the three groups. TcPO2 slowly decreased over the last 60 minutes of the experiment in the three groups, but when compared to the control group, the values remained significantly higher in animals that received the water enriched in O2 by electrolysis. In this protocol, water enriched in O2 by electrolysis lessened the decline of peripheral tissue oxygenation. This observation is compatible with the claim that the electrolytic process generates water clathrates which trap O2 and facilitate O2 diffusion along pressure gradients. Potential applications of O2-enriched water include an alternate method of oxygen supply.

  11. Carbonic anhydrase inhibition increases retinal oxygen tension and dilates retinal vessels

    DEFF Research Database (Denmark)

    Pedersen, Daniella Bach; Koch Jensen, Peter; la Cour, Morten

    2005-01-01

    Carbonic anhydrase inhibitors (CAIs) increase blood flow in the brain and probably also in the optic nerve and retina. Additionally they elevate the oxygen tension in the optic nerve in the pig. We propose that they also raise the oxygen tension in the retina. We studied the oxygen tension in the...... in the pig retina and optic nerve before and after dorzolamide injection. Also the retinal vessel diameters during carbonic anhydrase inhibition were studied....

  12. A method for volumetric retinal tissue oxygen tension imaging.

    Science.gov (United States)

    Felder, Anthony E; Wanek, Justin; Teng, Pang-Yu; Blair, Norman P; Shahidi, Mahnaz

    2018-01-01

    Inadequate retinal oxygenation occurs in many vision-threatening retinal diseases, including diabetic retinopathy, retinal vascular occlusions, and age-related macular degeneration. Therefore, techniques that assess retinal oxygenation are necessary to understand retinal physiology in health and disease. The purpose of the current study is to report a method for the three-dimensional (3D) imaging of retinal tissue oxygen tension (tPO 2 ) in rats. Imaging was performed in Long Evans pigmented rats under systemic normoxia (N = 6) or hypoxia (N = 3). A vertical laser line was horizontally scanned on the retina and a series of optical section phase-delayed phosphorescence images were acquired. From these images, phosphorescence volumes at each phase delay were constructed and a 3D retinal tPO 2 volume was generated. Retinal tPO 2 volumes were quantitatively analyzed by generating retinal depth profiles of mean tPO 2 (M tPO2 ) and the spatial variation of tPO 2 (SV tPO2 ). The effects of systemic condition (normoxia/hypoxia) and retinal depth on M tPO2 and SV tPO2 were determined by mixed linear model. Each 3D retinal tPO 2 volume was approximately 500 × 750 × 200 μm (horizontal × vertical × depth) and consisted of 45 en face tPO 2 images through the retinal depth. M tPO2 at the chorioretinal interface was significantly correlated with systemic arterial oxygen tension (P = 0.007; N = 9). There were significant effects of both systemic condition and retinal depth on M tPO2 and SV tPO2 , such that both were lower under hypoxia than normoxia and higher in the outer retina than inner retina (P < 0.001). For the first time, 3D imaging of retinal tPO 2 was demonstrated, with potential future application for assessment of physiological alterations in animal models of retinal diseases.

  13. Oxygen Tension in the Aqueous Humor of Human Eyes under Different Oxygenation Conditions

    Directory of Open Access Journals (Sweden)

    Farideh Sharifipour

    2013-01-01

    Full Text Available Purpose: To measure oxygen tension in the aqueous humor of human eyes under different oxygenation conditions. Methods: This prospective comparative interventional case series consisted of two parts. In the first part, 120 consecutive patients scheduled for cataract surgery were randomized into group I (control group in which surgery was performed under local anesthesia inhaling 21% oxygen; group II in whom general anesthesia using 50% oxygen was employed; and group III receiving general anesthesia with 100% oxygen. After aspirating 0.2 ml aqueous humor under sterile conditions, the aqueous sample and a simultaneously drawn arterial blood sample were immediately analyzed using a blood gas analyzer. In part II the same procedures were performed in 10 patients after fitting a contact lens and patching the eye for 20 minutes (group IV and in 10 patients after transcorneal delivery of oxygen at a flow rate of 5 L/min (group V. Results: Mean aqueous PO2 in groups I, II and III was 112.3±6.2, 141.1±20.4, and 170.1±27 mmHg, respectively (P values <0.001 and mean arterial PO2 was 85.7±7.9, 184.6±46, and 379.1±75.9 mmHg, respectively (P values <0.001. Aqueous PO2 was 77.2±9.2 mmHg in group IV and 152.3±10.9 mmHg in group V (P values <0.001. There was a significant correlation between aqueous and blood PO2 (r=0.537, P<0.001. The contribution of atmospheric oxygen to aqueous PO2 was 23.7%. Conclusion: Aqueous oxygen tension is mostly dependent on the systemic circulation and in part on the atmosphere. Increasing inspiratory oxygen and transcorneal oxygen delivery both increase aqueous PO2 levels.

  14. Transcutaneous oxygen pressure measurement in diabetic foot ulcers: mean values and cut-point for wound healing.

    Science.gov (United States)

    Yang, Chuan; Weng, Huan; Chen, Lihong; Yang, Haiyun; Luo, Guangming; Mai, Lifang; Jin, Guoshu; Yan, Li

    2013-01-01

    The purpose of this study was to investigate mean values and cut-point of transcutaneous oxygen pressure (TcPO2) measurement in patients with diabetic foot ulcers. Prospective, descriptive study. Sixty-one patients with diabetes mellitus and foot ulcers comprised the sample. The research setting was Sun Yat-sen Memorial Hospital of SunYat-sen University, Guangzhou, China. Participants underwent transcutaneous oxygen (TcPO2) measurement at the dorsum of foot. Patients were classified into 3 groups according to clinical outcomes: (1) ulcers healed with intact skin group, (2) ulcer improved, and (3) ulcer failed to improve. TcPO2 was assessed and cut-points for predicting diabetic foot ulcer healing were calculated. Thirty-six patients healed with intact skin, 8 experienced improvement, and 17 showed no improvement. Mean TcPO2 levels were significantly higher (Pfoot ulcers. In contrast, all patients with TcPO2≥ 40 mmHg achieved wound closure. Measurement of TcPO2 in the supine position revealed a cut-point value of 25 mmHg as the best threshold for predicting diabetic foot ulcer healing; the area under the curve using this cut-point was 0.838 (95% confidence interval = 0.700-0.976). The sensitivity, specificity, positive predictive value, and negative predictive value for TxPO2 were 88.6%, 82.4%, 90.7%, and 72.2%, respectively. TcPO2≥ 40 mmHg was associated with diabetic foot ulcer healing, but a TcPO2≤ 10 mmHg was associated with failure of wound healing. We found that a cut-point of 25 mmHg was most predictive of diabetic foot ulcer healing.

  15. Bladder urine oxygen tension for assessing renal medullary oxygenation in rabbits: experimental and modeling studies

    OpenAIRE

    Sgouralis, Ioannis; Kett, Michelle M.; Ow, Connie P. C.; Abdelkader, Amany; Layton, Anita T.; Gardiner, Bruce S.; Smith, David W.; Lankadeva, Yugeesh R.; Evans, Roger G.

    2016-01-01

    Oxygen tension (Po2) of urine in the bladder could be used to monitor risk of acute kidney injury if it varies with medullary Po2. Therefore, we examined this relationship and characterized oxygen diffusion across walls of the ureter and bladder in anesthetized rabbits. A computational model was then developed to predict medullary Po2 from bladder urine Po2. Both intravenous infusion of [Phe2,Ile3,Orn8]-vasopressin and infusion of NG-nitro-l-arginine reduced urinary Po2 and medullary Po2 (8–1...

  16. Encouraging effects of a short-term, adapted Nordic diet intervention on skin microvascular function and skin oxygen tension in younger and older adults.

    Science.gov (United States)

    Rogerson, David; McNeill, Scott; Könönen, Heidi; Klonizakis, Markos

    2018-05-01

    The microvascular benefits of regional diets appear in the literature; however, little is known about Nordic-type diets. We investigated the effects of a short-term, adapted, Nordic diet on microvascular function in younger and older individuals at rest and during activity. Thirteen young (mean age: 28 y; standard deviation: 5 y) and 15 older (mean age: 68 y; standard deviation: 6 y) participants consumed a modified Nordic diet for 4 wk. Laser Doppler flowmetry and transcutaneous oxygen monitoring were used to assess cutaneous microvascular function and oxygen tension pre- and postintervention; blood pressure, body mass, body fat percentage, ratings of perceived exertion, and peak heart rate during activity were examined concurrently. Axon-mediated vasodilation improved in older participants (1.17 [0.30] to 1.30 [0.30]; P Nordic diet might improve microvascular health. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Oxygen Tension Beneath Scleral Lenses of Different Clearances.

    Science.gov (United States)

    Giasson, Claude J; Morency, Jeanne; Melillo, Marc; Michaud, Langis

    2017-04-01

    To evaluate the relative partial pressure in oxygen (pO2) at the corneal surface under Boston XO2 scleral lenses (SL) fitted with targeted clearances of 200 and 400 μm (SL200 and SL400). During this prospective study, the right eyes of eight normal subjects were fitted with SL200 and SL400. Clearance, validated after 5 minutes of wear with an optical coherence tomograph, was used with lens thicknesses to calculate transmissibility and estimate pO2. Corneal pO2s were measured with an oxygen electrode after 5 minutes of (1) corneal exposure to calibrating gases with various pO2 or of (2) SL wear. Decays in pO2 were modeled to an exponential. Linear regression between exponent k of these decays and calibrating gas pO2s allowed for the calculation of corneal pO2 under SL. Differences between pO2s beneath SL200 and SL400 were tested with a mixed ANOVA. The estimated transmissibility based on thicknesses and clearances (239.7 ± 34.7; 434.5 ± 33.2 μm) predicted a corneal pO2 of 8.52 ± 0.51 and 6.37 ± 0.28% for SL200 and SL400. These values were close to measured pO2: 9.07 ± 0.86 and 6.19 ± 0.87% (mean ± SEM) (P time, an 18-mm scleral lens fitted with a 400-μm clearance reduces the oxygen tension available to the cornea by 30% compared to a similar lens fitted with a 200-μm clearance after 5 minutes of wear.

  18. Optic nerve oxygen tension in pigs and the effect of carbonic anhydrase inhibitors

    DEFF Research Database (Denmark)

    Stefánsson, E; Jensen, P K; Eysteinsson, T

    1999-01-01

    To evaluate how the oxygen tension of the optic nerve (ONP(O)2) is affected by the administration of the carbonic anhydrase inhibitors dorzolamide and acetazolamide and by alterations in oxygen and carbon dioxide in the breathing mixture.......To evaluate how the oxygen tension of the optic nerve (ONP(O)2) is affected by the administration of the carbonic anhydrase inhibitors dorzolamide and acetazolamide and by alterations in oxygen and carbon dioxide in the breathing mixture....

  19. Exercise transcutaneous oxygen pressure measurement has good sensitivity and specificity to detect lower extremity arterial stenosis assessed by computed tomography angiography

    OpenAIRE

    Koch, Caroline; Chauve, Emmanuel; Chaudru, S?gol?ne; Le Faucheur, Alexis; Jaquinandi, Vincent; Mah?, Guillaume

    2016-01-01

    Abstract Peripheral artery disease (PAD) is a highly prevalent disease diagnosed by the use of ankle-brachial index (ABI) at rest. In some clinical conditions (diabetes, renal insufficiency, advanced age), ABI can be falsely normal and other tests are required for the PAD diagnosis (American Heart Association statement). This study was conducted to determine the accuracy of exercise transcutaneous oxygen pressure measurement (exercise-TcPo2) in detection of arterial stenosis ?50% using comput...

  20. Simultaneous Monitoring of Vascular Oxygenation and Tissue Oxygen Tension of Breast Tumors Under Hyperbaric Oxygen Exposure

    Science.gov (United States)

    2008-04-01

    28. Alagoz, T., R. Buller, B. Anderson, K. Terrell , R...and oxygenation Ann . New Acad. Sci. 838 29–45 Chapman J D, Stobbe C C, Arnfield M R, Santus R, Lee J and McPhee M S 1991 Oxygen dependency of tumor

  1. Simultaneous Monitoring of Vascular Oxygenation and Tissue Oxygen Tension of Breast Tumors Under Hyperbaric Oxygen Exposure

    National Research Council Canada - National Science Library

    Xia, Mengna

    2005-01-01

    The goals of the study in the first stage are 1) to develop a mathematic model by which we can derive tumor blood flow and metabolic rate of oxygen from hemoglobin concentration during interventions, 2...

  2. Low physiologic oxygen tensions reduce proliferation and differentiation of human multipotent mesenchymal stromal cells

    Directory of Open Access Journals (Sweden)

    Handgretinger Rupert

    2010-01-01

    Full Text Available Abstract Background Human multipotent mesenchymal stromal cells (MSC can be isolated from various tissues including bone marrow. Here, MSC participate as bone lining cells in the formation of the hematopoietic stem cell niche. In this compartment, the oxygen tension is low and oxygen partial pressure is estimated to range from 1% to 7%. We analyzed the effect of low oxygen tensions on human MSC cultured with platelet-lysate supplemented media and assessed proliferation, morphology, chromosomal stability, immunophenotype and plasticity. Results After transferring MSC from atmospheric oxygen levels of 21% to 1%, HIF-1α expression was induced, indicating efficient oxygen reduction. Simultaneously, MSC exhibited a significantly different morphology with shorter extensions and broader cell bodies. MSC did not proliferate as rapidly as under 21% oxygen and accumulated in G1 phase. The immunophenotype, however, was unaffected. Hypoxic stress as well as free oxygen radicals may affect chromosomal stability. However, no chromosomal abnormalities in human MSC under either culture condition were detected using high-resolution matrix-based comparative genomic hybridization. Reduced oxygen tension severely impaired adipogenic and osteogenic differentiation of human MSC. Elevation of oxygen from 1% to 3% restored osteogenic differentiation. Conclusion Physiologic oxygen tension during in vitro culture of human MSC slows down cell cycle progression and differentiation. Under physiological conditions this may keep a proportion of MSC in a resting state. Further studies are needed to analyze these aspects of MSC in tissue regeneration.

  3. Fluid responsiveness predicted by transcutaneous partial pressure of oxygen in patients with circulatory failure: a prospective study.

    Science.gov (United States)

    Xu, Jingyuan; Peng, Xiao; Pan, Chun; Cai, Shixia; Zhang, Xiwen; Xue, Ming; Yang, Yi; Qiu, Haibo

    2017-12-01

    Significant effort has been devoted to defining parameters for predicting fluid responsiveness. Our goal was to study the feasibility of predicting fluid responsiveness by transcutaneous partial pressure of oxygen (PtcO 2 ) in the critically ill patients. This was a single-center prospective study conducted in the intensive care unit of a tertiary care teaching hospital. Shock patients who presented with at least one clinical sign of inadequate tissue perfusion, defined as systolic blood pressure 40 mmHg in previously hypertensive patients or the need for vasopressive drugs; urine output 4 mmol/l, for less than 24 h in the absence of a contraindication for fluids were eligible to participate in the study. PtcO 2 was continuously recorded before and during a passive leg raising (PLR) test, and then before and after a 250 ml rapid saline infusion in 10 min. Fluid responsiveness is defined as a change in the stroke volume ≥10% after 250 ml of volume infusion. Thirty-four patients were included, and 14 responded to volume expansion. In the responders, the mean arterial pressure, central venous pressure, cardiac output, stroke volume and PtcO 2 increased significantly, while the heart rate decreased significantly by both PLR and volume expansion. Changes in the stroke volume induced either by PLR or volume expansion were significantly greater in responders than in non-responders. The correlation between the changes in PtcO 2 and stroke volume induced by volume expansion was significant. Volume expansion induced an increase in the PtcO 2 of 14% and PLR induced an increase in PtcO 2 of 13% predicted fluid responsiveness. This study suggested the changes in PtcO 2 induced by volume expansion and a PLR test predicted fluid responsiveness in critically ill patients. Trial registration NCT02083757.

  4. In vivo mitochondrial oxygen tension measured by a delayed fluorescence lifetime technique

    NARCIS (Netherlands)

    Mik, Egbert G.; Johannes, Tanja; Zuurbier, Coert J.; Heinen, Andre; Houben-Weerts, Judith H. P. M.; Balestra, Gianmarco M.; Stap, Jan; Beek, Johan F.; Ince, Can

    2008-01-01

    Mitochondrial oxygen tension (mitoPO(2)) is a key parameter for cellular function, which is considered to be affected under various pathophysiological circumstances. Although many techniques for assessing in vivo oxygenation are available, no technique for measuring mitoPO(2) in vivo exists. Here we

  5. Radioprotection of mouse skin by WR-2721: the critical influence of oxygen tension

    International Nuclear Information System (INIS)

    Denekamp, J.; Michael, B.D.; Rojas, A.; Stewart, F.A.

    1982-01-01

    The epidermal clone assay has been used to study the radioprotective effect of WR-2721 on mouse skin under different conditions of oxygenation and under anoxia. The skin has shown a progressive decrease in sensitivity as the inspired gas has changed from 100% oxygen towards 0% oxygen. Compared with mice breathning 100% oxygen, those breathing air are partially protected. The inspired oxygen concentration to give half the full oxygen effect is 10-12%. The radioprotecton observed with 400 mg/kg WR-2721 is markedly dependent on the ambient oxygen concentration. The protection factor is 1.1 or less in mice breathing 5%, 1% or 0% oxygen. Protection is maximal (1.95) in air and in 50% oxygen and diminishes to 1.6 at higher oxygen tensions

  6. Bladder urine oxygen tension for assessing renal medullary oxygenation in rabbits: experimental and modeling studies

    Science.gov (United States)

    Sgouralis, Ioannis; Kett, Michelle M.; Ow, Connie P. C.; Abdelkader, Amany; Layton, Anita T.; Gardiner, Bruce S.; Smith, David W.; Lankadeva, Yugeesh R.

    2016-01-01

    Oxygen tension (Po2) of urine in the bladder could be used to monitor risk of acute kidney injury if it varies with medullary Po2. Therefore, we examined this relationship and characterized oxygen diffusion across walls of the ureter and bladder in anesthetized rabbits. A computational model was then developed to predict medullary Po2 from bladder urine Po2. Both intravenous infusion of [Phe2,Ile3,Orn8]-vasopressin and infusion of NG-nitro-l-arginine reduced urinary Po2 and medullary Po2 (8–17%), yet had opposite effects on renal blood flow and urine flow. Changes in bladder urine Po2 during these stimuli correlated strongly with changes in medullary Po2 (within-rabbit r2 = 0.87–0.90). Differences in the Po2 of saline infused into the ureter close to the kidney could be detected in the bladder, although this was diminished at lesser ureteric flow. Diffusion of oxygen across the wall of the bladder was very slow, so it was not considered in the computational model. The model predicts Po2 in the pelvic ureter (presumed to reflect medullary Po2) from known values of bladder urine Po2, urine flow, and arterial Po2. Simulations suggest that, across a physiological range of urine flow in anesthetized rabbits (0.1–0.5 ml/min for a single kidney), a change in bladder urine Po2 explains 10–50% of the change in pelvic urine/medullary Po2. Thus, it is possible to infer changes in medullary Po2 from changes in urinary Po2, so urinary Po2 may have utility as a real-time biomarker of risk of acute kidney injury. PMID:27385734

  7. Oxygen tension measurements of tumors growing in mice

    International Nuclear Information System (INIS)

    Adam, Markus F.; Dorie, Mary Jo; Brown, J. Martin

    1999-01-01

    Purpose: Clinical studies using the Eppendorf histograph have shown that patients whose tumors have a low pO 2 have worse local control after radiotherapy, and have higher metastatic rates. Because preclinical studies of methods of overcoming, or exploiting, hypoxia generally use transplanted tumors in mice, we have compared the oxygenation of mouse tumors with human tumors to determine the appropriateness of the transplanted mouse model for such preclinical studies. Methods and Materials: We evaluated the oxygenation status of subcutaneous (s.c.) tissue and of 12 intradermally (i.d.)- and 7 s.c.-growing mouse or human transplanted tumors in mice using the Eppendorf histograph, and compared the values obtained with measurements of human head and neck nodes. Results: The normal tissue pO 2 profile of air-breathing mice showed a nearly Gaussian distribution (38.2 ± 14.9 mmHg). Breathing 10% O 2 or carbogen resulted in dramatic changes in normal tissue oxygenation. Tumors growing intradermally in the back of air-breathing mice were extremely hypoxic and resistant to expected changes in oxygenation (carbogen breathing, size, and use of anesthetics). Tumors growing s.c. in the foot showed higher oxygen profiles with marked changes in oxygenation when exposing the animals to different levels of oxygen. However, the oxygenation of the mouse tumors transplanted in either site was only a fraction of that of the majority of human tumors. Conclusion: Experimental mouse tumors are markedly hypoxic, with median values of 10-20% of those of human tumors. Hence, mouse tumors are probably good models for the most hypoxic human tumors that respond poorly to radiotherapy; however, caution has to be exercised in extrapolating data from mouse to man

  8. A Method for Combined Retinal Vascular and Tissue Oxygen Tension Imaging.

    Science.gov (United States)

    Felder, Anthony E; Wanek, Justin; Tan, Michael R; Blair, Norman P; Shahidi, Mahnaz

    2017-09-06

    The retina requires adequate oxygenation to maintain cellular metabolism and visual function. Inner retinal oxygen metabolism is directly related to retinal vascular oxygen tension (PO 2 ) and inner retinal oxygen extraction fraction (OEF), whereas outer retinal oxygen consumption (QO 2 ) relies on oxygen availability by the choroid and is contingent upon retinal tissue oxygen tension (tPO 2 ) gradients across the retinal depth. Thus far, these oxygenation and metabolic parameters have been measured independently by different techniques in separate animals, precluding a comprehensive and correlative assessment of retinal oxygenation and metabolism dynamics. The purpose of the current study is to report an innovative optical system for dual oxyphor phosphorescence lifetime imaging to near-simultaneously measure retinal vascular PO 2 and tPO 2 in rats. The use of a new oxyphor with different spectral characteristics allowed differentiation of phosphorescence signals from the retinal vasculature and tissue. Concurrent measurements of retinal arterial and venous PO 2 , tPO 2 through the retinal depth, inner retinal OEF, and outer retinal QO 2 were demonstrated, permitting a correlative assessment of retinal oxygenation and metabolism. Future application of this method can be used to investigate the relations among retinal oxygen content, extraction and metabolism under pathologic conditions and thus advance knowledge of retinal hypoxia pathophysiology.

  9. Indomethacin decreases optic nerve oxygen tension by a mechanism other than cyclo-oxygenase inhibition

    DEFF Research Database (Denmark)

    Noergaard, M Hove; Pedersen, D Bach; Bang, K

    2008-01-01

    We investigated the effect of several Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), on the preoptic nerve oxygen tension (ONPO2), as indomethacin previously has demonstrated a strong decreasing effect on ONPO2. We tested whether these NSAIDs, like indomethacin, also reduce the increasing effect...

  10. Methyl sterol and cyclopropane fatty acid composition of Methylococcus capsulatus grown at low oxygen tensions

    Science.gov (United States)

    Jahnke, L. L.; Nichols, P. D.

    1986-01-01

    The sterol and fatty acid concentrations for M. capsulatus grown in fed-batch cultures over a wide range of oxygen tensions (0.1-10.6 percent) and at a constant methane level are evaluated. The analyses reveal that the biomass decreases as oxygen levels are lowered; the sterol concentration increases when the oxygen range is between 0.5-1.1 percent and decreases when the oxygen range is below 0.5 percent; and the amount of monounsaturated C16 decreases and the concentration of cyclopropane fatty acids increases after oxygen is reduced. It is noted that growth and membrane synthesis occur at low oxygen concentrations and that the synthesis of membrane lipids responds to growth conditions.

  11. Control of oxygen tension recapitulates zone-specific functions in human liver microphysiology systems.

    Science.gov (United States)

    Lee-Montiel, Felipe T; George, Subin M; Gough, Albert H; Sharma, Anup D; Wu, Juanfang; DeBiasio, Richard; Vernetti, Lawrence A; Taylor, D Lansing

    2017-10-01

    This article describes our next generation human Liver Acinus MicroPhysiology System (LAMPS). The key demonstration of this study was that Zone 1 and Zone 3 microenvironments can be established by controlling the oxygen tension in individual devices over the range of ca. 3 to 13%. The oxygen tension was computationally modeled using input on the microfluidic device dimensions, numbers of cells, oxygen consumption rates of hepatocytes, the diffusion coefficients of oxygen in different materials and the flow rate of media in the MicroPhysiology System (MPS). In addition, the oxygen tension was measured using a ratiometric imaging method with the oxygen sensitive dye, Tris(2,2'-bipyridyl) dichlororuthenium(II) hexahydrate (RTDP) and the oxygen insensitive dye, Alexa 488. The Zone 1 biased functions of oxidative phosphorylation, albumin and urea secretion and Zone 3 biased functions of glycolysis, α1AT secretion, Cyp2E1 expression and acetaminophen toxicity were demonstrated in the respective Zone 1 and Zone 3 MicroPhysiology System. Further improvements in the Liver Acinus MicroPhysiology System included improved performance of selected nonparenchymal cells, the inclusion of a porcine liver extracellular matrix to model the Space of Disse, as well as an improved media to support both hepatocytes and non-parenchymal cells. In its current form, the Liver Acinus MicroPhysiology System is most amenable to low to medium throughput, acute through chronic studies, including liver disease models, prioritizing compounds for preclinical studies, optimizing chemistry in structure activity relationship (SAR) projects, as well as in rising dose studies for initial dose ranging. Impact statement Oxygen zonation is a critical aspect of liver functions. A human microphysiology system is needed to investigate the impact of zonation on a wide range of liver functions that can be experimentally manipulated. Because oxygen zonation has such diverse physiological effects in the liver, we

  12. Multiple oxygen tension environments reveal diverse patterns of transcriptional regulation in primary astrocytes.

    Directory of Open Access Journals (Sweden)

    Wayne Chadwick

    Full Text Available The central nervous system normally functions at O(2 levels which would be regarded as hypoxic by most other tissues. However, most in vitro studies of neurons and astrocytes are conducted under hyperoxic conditions without consideration of O(2-dependent cellular adaptation. We analyzed the reactivity of astrocytes to 1, 4 and 9% O(2 tensions compared to the cell culture standard of 20% O(2, to investigate their ability to sense and translate this O(2 information to transcriptional activity. Variance of ambient O(2 tension for rat astrocytes resulted in profound changes in ribosomal activity, cytoskeletal and energy-regulatory mechanisms and cytokine-related signaling. Clustering of transcriptional regulation patterns revealed four distinct response pattern groups that directionally pivoted around the 4% O(2 tension, or demonstrated coherent ascending/decreasing gene expression patterns in response to diverse oxygen tensions. Immune response and cell cycle/cancer-related signaling pathway transcriptomic subsets were significantly activated with increasing hypoxia, whilst hemostatic and cardiovascular signaling mechanisms were attenuated with increasing hypoxia. Our data indicate that variant O(2 tensions induce specific and physiologically-focused transcript regulation patterns that may underpin important physiological mechanisms that connect higher neurological activity to astrocytic function and ambient oxygen environments. These strongly defined patterns demonstrate a strong bias for physiological transcript programs to pivot around the 4% O(2 tension, while uni-modal programs that do not, appear more related to pathological actions. The functional interaction of these transcriptional 'programs' may serve to regulate the dynamic vascular responsivity of the central nervous system during periods of stress or heightened activity.

  13. The Role of Oxygen Tension in Penile Erection and Its Relationship to Erectile Dysfunction

    Directory of Open Access Journals (Sweden)

    Jong-Kwan Park

    2004-01-01

    Full Text Available The corpus cavernosum of the penis is one of the few vascular beds in which there is a change in oxygen tension with function (blood PO2 25-40mm Hg in the flaccid state, and 90-100mm Hg in the erect state. This change in oxygen tension exposes the components of the corpus cavernosum to a variety of cytokines, humoral, vasoactive, and growth factors which may affect the structure and function of the endothelial cells, smooth muscle cells, neurons and extracellular matrix. Among these cell types, endothelial cells are the first line of defense to blood-borne stress and can affect the underlying smooth muscle via paracrine mechanisms. Impotence is defined as the inability to obtain or sustain an erection sufficient for vaginal penetration and can result from a variety of pathological conditions, vascular disease, endocrine disease, neurological disease, and psychogenic disorders. The penis is a vascular organ and as such is susceptible to the effects of vascular diseases. This review will discuss the basic etiology of erection and vasculogenic erectile dysfunction and explore the role oxygen tension in regulating various cellular and humoral factors as well as trabecular structure and function.

  14. [Effect of different oxygen tension on the cytoskeleton remodeling of goat temporomandibular joint disc cells].

    Science.gov (United States)

    Xiaolan, He; Guangjie, Bao; Linglu, Sun; Xue, Zhang; Shanying, Bao; Hong, Kang

    2017-08-01

    Objective The effect of different oxygen tensions on the cytoskeleton remodeling of goat temporomandibular joint (TMJ) disc cells were investigated. Methods Goat TMJ disc cells were cultured under normoxia (21% O₂) and hypoxia (2%, 4%, and 8% O₂). Toluidine blue, picrosirius red, and type Ⅰ collagen immunocytochemical staining were performed to observe the changes in cell phenotype under different oxygen levels. Immunofluorescent staining and real-time reverse transcription-polymerase chain reaction analysis were then performed to identify actin, tubulin, and vimentin in the cultured disc cells. Results TMJ disc cells still displayed fibroblast characteristics under different oxygen levels and their cytoskeletons had regular arrangement. The fluorescence intensities of actin and vimentin were lowest at 4% O₂(P0.05). Actin mRNA levels were considerably decreased at 2% O₂ and 4% O₂ in hypoxic conditions, while actin mRNA expression was highest in 21% O₂. Tubulin mRNA levels considerably increased at 2% O₂, while tubulin mRNA expression was lowest in 8% O₂ (Plevels among these oxygen levels (Poxygen tensions, and 2% O₂ may be the optimal oxygen level required to proliferate TMJ disc cells.

  15. [Long-term expansion of multipotent mesenchymal stromal cells under reduced oxygen tension].

    Science.gov (United States)

    Rylova, Iu V; Buravkova, L B

    2013-01-01

    We have shown that the decrease in oxygen tension in the culture medium of multipotent mesenchymal stromal cells (MMSCs) results in a short-term reduction in the proportion of CD73(+)-cells in the population, without effecting the number of cells expressing other constitutive surface markers (CD90 and CD105). In this case, the heterogeneity of the cell population declined: large spread cells disappeared. The proliferative activity of MMSCs significantly increased and remained stable in conditions in which the oxygen content was close to the tissue oxygen levels (5% O2). At lower oxygen concentration, proliferative activity of the cells gradually reduced from passages 3-4. The increase in proliferative activity was not accompanied by increased expression of telomerase gene indicateding the alsance of cell transformation. However, genome-wide analysis of MMSC gene expression level revealed changes in expression of cyclins (CCND2 and PCNA), regulatory subunit cyclin-dependent kinase (CKS2) and an inhibitor of cyclin-dependent kinase (CDKN2C), regulating the cell cycle, which is obviously facilitated the increase in the proliferative capacity of cells at lower oxygen tension.

  16. Oxidative stress under ambient and physiological oxygen tension in tissue culture

    Science.gov (United States)

    Jagannathan, Lakshmanan; Cuddapah, Suresh; Costa, Max

    2016-01-01

    Oxygen (O2) levels range from 2–9% in vivo. However, cell culture experiments are performed at atmospheric O2 levels (21%). Oxidative stress due to generation of reactive oxygen species (ROS) in cells cultured at higher than physiological levels is implicated in multitude of deleterious effects including DNA damage, genomic instability and senescence. In addition, oxidative stress activates redox sensitive transcription factors related to inflammatory signaling and apoptotic signaling. Furthermore, several chromatin-modifying enzymes are affected by ROS, potentially impacting epigenetic regulation of gene expression. While primary cells are cultured at lower O2 levels due to their inability to grow at higher O2, the immortalized cells, which display no such apparent growth difficulties, are typically cultured at 21% O2. This review will provide an overview of issues associated with increased oxygen levels in in vitro cell culture and point out the benefits of using lower levels of oxygen tension even for immortalized cells. PMID:27034917

  17. Microcomputer-based system for registration of oxygen tension in peripheral muscle.

    Science.gov (United States)

    Odman, S; Bratt, H; Erlandsson, I; Sjögren, L

    1986-01-01

    For registration of oxygen tension fields in peripheral muscle a microcomputer based system was designed on the M6800 microprocessor. The system was designed to record the signals from a multiwire oxygen electrode, MDO, which is a multiwire electrode for measuring oxygen on the surface of an organ. The system contained patient safety isolation unit built on optocopplers and the upper frequency limit was 0.64 Hz. Collected data were corrected for drift and temperature changes during the measurement by using pre- and after calibrations and a linear compensation technique. Measure drift of the electrodes were proved to be linear and thus the drift could be compensated for. The system was tested in an experiment on pig. To study the distribution of oxygen statistically mean, standard deviation, skewness and curtosis were calculated. To see changes or differences between histograms a Kolmogorv-Smirnov test was used.

  18. The Effect of Non-nutritive Sucking on Transcutaneous Oxygen Saturation in Neonates under the Nasal Continuous Positive Airway Pressure (CPAP

    Directory of Open Access Journals (Sweden)

    Mousa Ahmadpour-kacho

    2017-03-01

    Full Text Available BackgroundSeveral beneficial effects of non-nutritive sucking in infants, including the physiological stability, relaxation, better transition from tube feeding to oral feeding have been reported. But its effect on oxygen saturation in neonates under the Nasal Continuous Positive Airway Pressure (NCPAPو (is not so clear. This study aimed to investigate the effects of non-nutritive sucking on transcutaneous oxygen saturation levels of neonates treated with NCPAP.Materials and MethodsThis quasi-experimental study was done on 25 preterm neonates, hospitalized with a diagnosis of respiratory distress, required NCPAP, in the neonatal intensive care unit (NICU at the Ayatollah Rouhani Hospital and Babol Clinic, North of Iran. Non-nutritive sucking was elicited by a standard pacifier appropriate to their age one hour a day, and the mean oxygen saturation was measured before and after intervention by cardiopulmonary monitoring (Saadat Co., Iran. Data analyzed using SPSS-18.0 software.ResultsIn the 25 cases studied, the mean oxygen saturation values ​​before performing non-nutritive sucking was 96.31±2.88%, which was changed to 98.35±1.6% after intervention, and this increase was statistically significant (P = 0.004.Results showed that the gender, birth weight and gestational age of neonates had no effect on mean Blood oxygen saturation (SpO2level.ConclusionAccording to the results, using the non-nutritive sucking in premature neonates under the NCPAP, can improve oxygenation.

  19. Effect of epidural blockade and oxygen therapy on changes in subcutaneous oxygen tension after abdominal surgery

    DEFF Research Database (Denmark)

    Rosenberg, J; Pedersen, U; Erichsen, C J

    1994-01-01

    The effect of oxygen therapy (37% by face mask) and epidural local anesthetic blockade (9 ml 0.5% bupivacaine at Th9-11 level) on wound oxygenation was evaluated in eight otherwise healthy patients undergoing elective colorectal resection. The patients were monitored continuously for subcutaneous...... without epidural blockade and 15 (10-20) min with blockade (P surgery....

  20. Effect of oxygen tension on bioenergetics and proteostasis in young and old myoblast precursor cells.

    Science.gov (United States)

    Konigsberg, M; Pérez, V I; Ríos, C; Liu, Y; Lee, S; Shi, Y; Van Remmen, H

    2013-01-01

    In the majority of studies using primary cultures of myoblasts, the cells are maintained at ambient oxygen tension (21% O2), despite the fact that physiological O2 at the tissue level in vivo is much lower (~1-5% O2). We hypothesized that the cellular response in presence of high oxygen concentration might be particularly important in studies comparing energetic function or oxidative stress in cells isolated from young versus old animals. To test this, we asked whether oxygen tension plays a role in mitochondrial bioenergetics (oxygen consumption, glycolysis and fatty acid oxidation) or oxidative damage to proteins (protein disulfides, carbonyls and aggregates) in myoblast precursor cells (MPCs) isolated from young (3-4 m) and old (29-30 m) C57BL/6 mice. MPCs were grown under physiological (3%) or ambient (21%) O2 for two weeks prior to exposure to an acute oxidative insult (H2O2). Our results show significantly higher basal mitochondrial respiration in young versus old MPCs, an increase in basal respiration in young MPCs maintained at 3% O2 compared to cells maintained at 21% O2, and a shift toward glycolytic metabolism in old MPCs grown at 21% O2. H2O2 treatment significantly reduced respiration in old MPCs grown at 3% O2 but did not further repress respiration at 21% O2 in old MPCs. Oxidative damage to protein was higher in cells maintained at 21% O2 and increased in response to H2O2 in old MPCs. These data underscore the importance of understanding the effect of ambient oxygen tension in cell culture studies, in particular studies measuring oxidative damage and mitochondrial function.

  1. Oxygen tension regulates the osteogenic, chondrogenic and endochondral phenotype of bone marrow derived mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Sheehy, Eamon J.; Buckley, Conor T. [Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin, Dublin 2 (Ireland); Kelly, Daniel J., E-mail: kellyd9@tcd.ie [Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin, Dublin 2 (Ireland)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Expansion in low oxygen enhances MSC proliferation and osteogenesis. Black-Right-Pointing-Pointer Differentiation in low oxygen enhances chondrogenesis and suppresses hypertrophy. Black-Right-Pointing-Pointer Oxygen can regulate the MSC phenotype for use in tissue engineering applications. -- Abstract: The local oxygen tension is a key regulator of the fate of mesenchymal stem cells (MSCs). The objective of this study was to investigate the effect of a low oxygen tension during expansion and differentiation on the proliferation kinetics as well as the subsequent osteogenic and chondrogenic potential of MSCs. We first hypothesised that expansion in a low oxygen tension (5% pO{sub 2}) would improve both the subsequent osteogenic and chondrogenic potential of MSCs compared to expansion in a normoxic environment (20% pO{sub 2}). Furthermore, we hypothesised that chondrogenic differentiation in a low oxygen environment would suppress hypertrophy of MSCs cultured in both pellets and hydrogels used in tissue engineering strategies. MSCs expanded at 5% pO{sub 2} proliferated faster forming larger colonies, resulting in higher cell yields. Expansion at 5% pO{sub 2} also enhanced subsequent osteogenesis of MSCs, whereas differentiation at 5% pO{sub 2} was found to be a more potent promoter of chondrogenesis than expansion at 5% pO{sub 2}. Greater collagen accumulation, and more intense staining for collagen types I and X, was observed in pellets maintained at 20% pO{sub 2} compared to 5% pO{sub 2}. Both pellets and hydrogels stained more intensely for type II collagen when undergoing chondrogenesis in a low oxygen environment. Differentiation at 5% pO{sub 2} also appeared to inhibit hypertrophy in both pellets and hydrogels, as demonstrated by reduced collagen type X and Alizarin Red staining and alkaline phosphatase activity. This study demonstrates that the local oxygen environment can be manipulated in vitro to either stabilise a

  2. Low Oxygen Tension Enhances Expression of Myogenic Genes When Human Myoblasts Are Activated from G0 Arrest

    DEFF Research Database (Denmark)

    Sellathurai, Jeeva; Nielsen, Joachim; Hejbøl, Eva Kildall

    2016-01-01

    -PCR, immunocytochemistry and western blot. RESULTS AND CONCLUSIONS: We found an increase in proliferation rate of myoblasts when activated at a low oxygen tension (1% O2) compared to 21% O2. In addition, the gene expression studies showed up regulation of the myogenesis related genes PAX3, PAX7, MYOD, MYOG (myogenin), MET......, NCAM, DES (desmin), MEF2A, MEF2C and CDH15 (M-cadherin), however, the fraction of DES and MYOD positive cells was not increased by low oxygen tension, indicating that 1% O2 may not have a functional effect on the myogenic response. Furthermore, the expression of genes involved in the TGFβ, Notch...... and Wnt signaling pathways were also up regulated in low oxygen tension. The differences in gene expression were most pronounced at day one after activation from G0-arrest, thus the initial activation of myoblasts seemed most sensitive to changes in oxygen tension. Protein expression of HES1 and β...

  3. Impact of low oxygen tension on stemness, proliferation and differentiation potential of human adipose-derived stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jane Ru; Pingguan-Murphy, Belinda; Wan Abas, Wan Abu Bakar [Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Noor Azmi, Mat Adenan; Omar, Siti Zawiah [Department of Obstetrics and Gynaecology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Chua, Kien Hui [Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia); Wan Safwani, Wan Kamarul Zaman, E-mail: wansafwani@um.edu.my [Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia)

    2014-05-30

    Highlights: • Hypoxia maintains the stemness of adipose-derived stem cells (ASCs). • ASCs show an increased proliferation rate under low oxygen tension. • Oxygen level as low as 2% enhances the chondrogenic differentiation potential of ASCs. • HIF-1α may regulate the proliferation and differentiation activities of ASCs under hypoxia. - Abstract: Adipose-derived stem cells (ASCs) have been found adapted to a specific niche with low oxygen tension (hypoxia) in the body. As an important component of this niche, oxygen tension has been known to play a critical role in the maintenance of stem cell characteristics. However, the effect of O{sub 2} tension on their functional properties has not been well determined. In this study, we investigated the effects of O{sub 2} tension on ASCs stemness, differentiation and proliferation ability. Human ASCs were cultured under normoxia (21% O{sub 2}) and hypoxia (2% O{sub 2}). We found that hypoxia increased ASC stemness marker expression and proliferation rate without altering their morphology and surface markers. Low oxygen tension further enhances the chondrogenic differentiation ability, but reduces both adipogenic and osteogenic differentiation potential. These results might be correlated with the increased expression of HIF-1α under hypoxia. Taken together, we suggest that growing ASCs under 2% O{sub 2} tension may be important in expanding ASCs effectively while maintaining their functional properties for clinical therapy, particularly for the treatment of cartilage defects.

  4. Indomethacin lowers optic nerve oxygen tension and reduces the effect of carbonic anhydrase inhibition and carbon dioxide breathing

    DEFF Research Database (Denmark)

    Pedersen, D B; Eysteinsson, T; Stefánsson, E

    2004-01-01

    Prostaglandins are important in blood flow regulation. Carbon dioxide (CO(2)) breathing and carbonic anhydrase inhibition increase the oxygen tension in the retina and optic nerve. To study the mechanism of this effect and the role of cyclo-oxygenase in the regulation of optic nerve oxygen tension...... (ONPO(2)), the authors investigated how indomethacin affects ONPO(2) and the ONPO(2) increases caused by CO(2) breathing and carbonic anhydrase inhibition in the pig....

  5. Cerebral interstitial tissue oxygen tension, pH, HCO3, CO2.

    Science.gov (United States)

    Charbel, F T; Hoffman, W E; Misra, M; Hannigan, K; Ausman, J I

    1997-10-01

    There are many techniques for monitoring the injured brain following trauma, subarachnoid hemorrhage, or surgery. It is thought that the major determinants for recovery of injured cerebral tissue are oxygen, glucose delivery, and the clearance of metabolites. These factors, at optimal levels, are probably responsible for the regaining of neuronal functions. These parameters are in turn dependent on the tissue's blood flow and metabolism. We have been using a single, compact, polyethylene sensor, the Paratrend 7 for the measurement of cerebral oxygen tension, CO2, pH, and temperature. This sensor is designed for continuous blood gas analysis to aid in monitoring neurosurgical patients, both during surgery and in the intensive care unit. Using the Paratrend 7 sensor, we found the normal range of values to be: PO2 33 +/- 11 mm Hg; PCO2 48 +/- 7 mm Hg; pH 7.19 +/- 0.11. Critical measurements are considered to be tissue PO2 60 mm Hg, and pH effective method of measuring tissue cerebral oxygen tension, along with carbon dioxide levels, pH, and temperature.

  6. Oxygen tension and prediction of the radiation response. Polarographic study in human breast cancer

    International Nuclear Information System (INIS)

    Pappova, N.; Siracka, E.

    1982-01-01

    Serial polarographic measurement of the tissue oxygen tension (pO 2 ) was made in the course of fractionated irradiation (preoperative or sole treatment) of advanced breast cancer in 24 patients. In responsive tumors an increase in pO 2 appeared sooner before expressive tumor size reduction became noticeable. Repeated recording of unchanged pO 2 values proved to be a good prognostic indicator of local failure. The study made on this tumor model showed that serial polarographic pO 2 determinations with suitable electrodes causing minimal trauma and providing consistent and reproductive data about changes in tumor microcirculation and oxygenation may enlarge the scale of indicators of radiation response. (author)

  7. The influence of ictal cutaneous allodynia on the response to occipital transcutaneous electrical stimulation in chronic migraine and chronic tension-type headache: a randomized, sham-controlled study.

    Science.gov (United States)

    Bono, F; Salvino, D; Mazza, M R; Curcio, M; Trimboli, M; Vescio, B; Quattrone, A

    2015-04-01

    The objective of this article is to determine whether cutaneous allodynia (CA) influences the response to treatment with occipital transcutaneous electrical stimulation (OTES) in chronic migraine (CM) and chronic tension-type headache (CTTH). One hundred and sixty consecutive patients with CM or CTTH were randomized to be treated with real or sham OTES stimulation three times a day for two consecutive weeks. All patients completed the validated 12-item allodynia symptom checklist for assessing the presence and the severity of CA during headache attack. Primary end-point was change (≥50%) in number of monthly headache-free days. There was a significant difference in the percentage of responders in the real OTES compared with sham OTES group (p headache-free days in the allodynic patients with CM and CTTH treated both with real and sham OTES, while the number of headache-free days per month was significantly reduced in the real (86%) but not in the sham group (7%) of non-allodynic patients with CTTH and CM. Severe CA is associated with decreased response to treatment with OTES in patients with CM and CTTH. © International Headache Society 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  8. Evaluation of multi-exponential curve fitting analysis of oxygen-quenched phosphorescence decay traces for recovering microvascular oxygen tension histograms

    NARCIS (Netherlands)

    Bezemer, Rick; Faber, Dirk J.; Almac, Emre; Kalkman, Jeroen; Legrand, Matthieu; Heger, Michal; Ince, Can

    2010-01-01

    Although it is generally accepted that oxygen-quenched phosphorescence decay traces can be analyzed using the exponential series method (ESM), its application until now has been limited to a few (patho)physiological studies, probably because the reliability of the recovered oxygen tension (pO(2))

  9. Effect of supplemental oxygen versus dobutamine administration on liver oxygen tension in dPP-guided normovolemic pigs.

    Science.gov (United States)

    Pestel, G; Fukui, K; Hager, H; Kurz, A; Hiltebrand, L

    2009-01-01

    Difference in pulse pressure (dPP) confirms adequate intravascular filling as a prerequisite for tissue perfusion. We hypothesized that both oxygen and dobutamine increase liver tissue oxygen tension (ptO(2)). Eight anesthetized pigs received dPP-guided fluid management. Hepatic pO(2) was measured with Clark-type electrodes placed subcapsularly, and on the liver surface. Pigs received: (1) supplemental oxygen (F(i)O(2) 1.0); (2) dobutamine 2.5 microg/kg/min, and (3) dobutamine 5 microg/kg/min. Data were analyzed using repeated-measures ANOVA followed by a Tukey post-test for multiple comparisons. ptO(2 )measured subcapsularly and at the liver surface were compared using the Bland-Altman plot. Variation in F(i)O(2) changed local hepatic tissue ptO(2) [subcapsular measurement: 39 +/- 12 (F(i)O(2) 0.3), 89 +/- 35 mm Hg (F(i)O(2) 1.0, p = 0.01 vs. F(i)O(2) 0.3), 44 +/- 10 mm Hg (F(i)O(2) 0.3, p = 0.05 vs. F(i)O(2) 1.0); surface measurement: 52 +/- 35 (F(i)O(2) 0.3), 112 +/- 24 mm Hg (F(i)O(2) 1.0, p = 0.001 vs. F(i)O(2) 0.3), 54 +/- 24 mm Hg (F(i)O(2) 0.3, p = 0.001 vs. F(i)O(2) 1.0)]. Surface measurements were widely scattered compared to subcapsular measurements (bias: -15 mm Hg, precision: 76.3 mm Hg). Dobutamine did not affect hepatic oxygenation. Supplemental oxygen increased hepatic tissue pO(2) while dobutamine did not. Although less invasive, the use of surface measurements is discouraged. Copyright 2009 S. Karger AG, Basel.

  10. Enhanced dopaminergic differentiation of human neural stem cells by synergistic effect of Bcl-xL and reduced oxygen tension

    DEFF Research Database (Denmark)

    Krabbe, Christina; Courtois, Elise; Jensen, Pia

    2009-01-01

    Neural stem cells constitute a promising source of cells for transplantation in Parkinson's disease, but a protocol for controlled dopaminergic differentiation is not yet available. Here we investigated the effect of the anti-apoptotic protein Bcl-x(L) and oxygen tension on dopaminergic different......Neural stem cells constitute a promising source of cells for transplantation in Parkinson's disease, but a protocol for controlled dopaminergic differentiation is not yet available. Here we investigated the effect of the anti-apoptotic protein Bcl-x(L) and oxygen tension on dopaminergic...... days at 20% oxygen, hVMbcl-x(L) cultures contained proportionally more tyrosine hydroxylase(TH)-positive cells than hVM1 control cultures. This difference was significantly potentiated from 11 +/- 0.8% to 17.2 +/- 0.2% of total cells when the oxygen tension was lowered to 3%. Immunocytochemistry and Q...

  11. Reactive oxygen species-driven HIF1α triggers accelerated glycolysis in endothelial cells exposed to low oxygen tension

    International Nuclear Information System (INIS)

    Paik, Jin-Young; Jung, Kyung-Ho; Lee, Jin-Hee; Park, Jin-Won; Lee, Kyung-Han

    2017-01-01

    Endothelial cells and their metabolic state regulate glucose transport into underlying tissues. Here, we show that low oxygen tension stimulates human umbilical vein endothelial cell 18 F–fluorodeoxyglucose ( 18 F–FDG) uptake and lactate production. This was accompanied by augmented hexokinase activity and membrane Glut-1, and increased accumulation of hypoxia-inducible factor-1α (HIF1α). Restoration of oxygen reversed the metabolic effect, but this was blocked by HIF1α stabilization. Hypoxia-stimulated 18 F–FDG uptake was completely abrogated by silencing of HIF1α expression or by a specific inhibitor. There was a rapid and marked increase of reactive oxygen species (ROS) by hypoxia, and ROS scavenging or NADPH oxidase inhibition completely abolished hypoxia-stimulated HIF1α and 18 F–FDG accumulation, placing ROS production upstream of HIF1α signaling. Hypoxia-stimulated HIF1α and 18 F–FDG accumulation was blocked by the protein kinase C (PKC) inhibitor, staurosporine. The phosphatidylinositol 3-kinase (PI3K) inhibitor, wortmannin, blocked hypoxia-stimulated 18 F–FDG uptake and attenuated hypoxia-responsive element binding of HIF1α without influencing its accumulation. Thus, ROS-driven HIF1α accumulation, along with PKC and PI3K signaling, play a key role in triggering accelerated glycolysis in endothelial cells under hypoxia, thereby contributing to 18 F–FDG transport.

  12. Towards a quantitative understanding of oxygen tension and cell density evolution in fibrin hydrogels.

    Science.gov (United States)

    Demol, Jan; Lambrechts, Dennis; Geris, Liesbet; Schrooten, Jan; Van Oosterwyck, Hans

    2011-01-01

    The in vitro culture of hydrogel-based constructs above a critical size is accompanied by problems of unequal cell distribution when diffusion is the primary mode of oxygen transfer. In this study, an experimentally-informed mathematical model was developed to relate cell proliferation and death inside fibrin hydrogels to the local oxygen tension in a quantitative manner. The predictive capacity of the resulting model was tested by comparing its outcomes to the density, distribution and viability of human periosteum derived cells (hPDCs) that were cultured inside fibrin hydrogels in vitro. The model was able to reproduce important experimental findings, such as the formation of a multilayered cell sheet at the hydrogel periphery and the occurrence of a cell density gradient throughout the hydrogel. In addition, the model demonstrated that cell culture in fibrin hydrogels can lead to complete anoxia in the centre of the hydrogel for realistic values of oxygen diffusion and consumption. A sensitivity analysis also identified these two parameters, together with the proliferation parameters of the encapsulated cells, as the governing parameters for the occurrence of anoxia. In conclusion, this study indicates that mathematical models can help to better understand oxygen transport limitations and its influence on cell behaviour during the in vitro culture of cell-seeded hydrogels. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Effect of body position and oxygen tension on foramen ovale recruitment.

    Science.gov (United States)

    Moses, Kayla L; Beshish, Arij G; Heinowski, Nicole; Baker, Kim R; Pegelow, David F; Eldridge, Marlowe W; Bates, Melissa L

    2015-01-01

    While there is an increased prevalence of stroke at altitude in individuals who are considered to be low risk for thrombotic events, it is uncertain how venous thrombi reach the brain. The patent foramen ovale (PFO) is a recruitable intracardiac shunt between the right and left atrium. We aimed to determine whether body position and oxygen tension affect blood flow through the PFO in healthy adults. We hypothesized that hypoxia and body positions that promote right atrial filling would independently recruit the PFO. Subjects with a PFO (n = 11) performed 11 trials, combining four different fractions of inhaled oxygen (FiO₂) (1.0, 0.21, 0.15, and 0.10) and three positions (upright, supine, and 45° head down), with the exception of FiO₂ = 0.10, while 45° head down. After 5 min in each position, breathing the prescribed oxygen tension, saline bubbles were injected into an antecubital vein and a four-chamber echocardiogram was obtained to evaluate PFO recruitment. We observed a high incidence of PFO recruitment in all conditions, with increased recruitment in response to severe hypoxia and some contribution of body position at moderate levels of hypoxia. We suspect that increased pulmonary vascular pressure, secondary to hypoxia-induced pulmonary vasoconstriction, increased right atrial pressure enough to recruit the PFO. Additionally, we hypothesize that the minor increase in breathing resistance that was added by the mouthpiece, used during experimental trials, affected intrathoracic pressure and venous return sufficiently to recruit the PFO. Copyright © 2015 the American Physiological Society.

  14. Oxygen tension is a determinant of the matrix-forming phenotype of cultured human meniscal fibrochondrocytes.

    Directory of Open Access Journals (Sweden)

    Adetola B Adesida

    Full Text Available BACKGROUND: Meniscal cartilage displays a poor repair capacity, especially when injury is located in the avascular region of the tissue. Cell-based tissue engineering strategies to generate functional meniscus substitutes is a promising approach to treat meniscus injuries. Meniscus fibrochondrocytes (MFC can be used in this approach. However, MFC are unable to retain their phenotype when expanded in culture. In this study, we explored the effect of oxygen tension on MFC expansion and on their matrix-forming phenotype. METHODOLOGY/PRINCIPAL FINDINGS: MFC were isolated from human menisci followed by basic fibroblast growth factor (FGF-2 mediated cell expansion in monolayer culture under normoxia (21%O(2 or hypoxia (3%O(2. Normoxia and hypoxia expanded MFC were seeded on to a collagen scaffold. The MFC seeded scaffolds (constructs were cultured in a serum free chondrogenic medium for 3 weeks under normoxia and hypoxia. Constructs containing normoxia-expanded MFC were subsequently cultured under normoxia while those formed from hypoxia-expanded MFC were subsequently cultured under hypoxia. After 3 weeks of in vitro culture, the constructs were assessed biochemically, histologically and for gene expression via real-time reverse transcription-PCR assays. The results showed that constructs under normoxia produced a matrix with enhanced mRNA ratio (3.5-fold higher; p<0.001 of collagen type II to I. This was confirmed by enhanced deposition of collagen II using immuno-histochemistry. Furthermore, the constructs under hypoxia produced a matrix with higher mRNA ratio of aggrecan to versican (3.5-fold, p<0.05. However, both constructs had the same capacity to produce a glycosaminoglycan (GAG -specific extracellular matrix. CONCLUSIONS: Our data provide evidence that oxygen tension is a key player in determining the matrix phenotype of cultured MFC. These findings suggest that the use of normal and low oxygen tension during MFC expansion and subsequent neo

  15. Oxygen tension and oocyte density during in vitro maturation affect the in vitro fertilization of bovine oocytes

    Directory of Open Access Journals (Sweden)

    Angelo Bertani Giotto

    2015-12-01

    Full Text Available Oocyte maturation is the key factor affecting the fertilization and embryonic development. Factors such as oocyte density and oxygen tension can directly influence the IMV. Thus, the objective of this study was to evaluate the effect of the association of oxygen tensions (5% or 20% with different oocyte densities (1:10?l or 1:20?l in the in vitro maturation (IVM of bovine oocytes on maturation and fertilization rates, ROS production and antioxidant activity. Three experiments were performed with bovine oocytes that were obtained from slaughterhouse ovaries. After selection, the oocytes were randomly distributed in four treatments: 1:10/5%; 1:10/20%; 1:20/5%and 1:20/20% for each experiment. In experiment I, nuclear maturation status and cytoplasmic maturation were evaluated through detection of the first polar body by immunofluorescence and the mitochondrial reorganization assay. In experiment II, ROS production and antioxidant activity were analyzed in oocytes and IVM medium after 24 h of maturation through detection of ROS, reduced glutathione (GSH and Superoxide dismutase activity by spectrofluorimetric methods. In experiment III, fertilization was evaluated through pronucleus formation, sperm penetration with or without decondensation and polyspermy rates by immunofluorescence. In experiment I, the nuclear maturation and cytoplasmic maturation were similar among treatments (P>0.05. In experiment II, reactive oxygen species in oocytes were elevated in treatments with low oxygen tension which was independent of oocyte density (P<0.05. Additionally, ROS levels in IVM medium were higher in treatments with high oocyte density by volume of medium, which was independent of oxygen tension (P<0.05. In Experiment III, the fertilization and penetration rates were higher in the treatment with 20% oxygen tension and high oocyte density (P<0.05. Furthermore, a high incidence of polyspermy was observed in groups with high oxygen tension and low oocyte

  16. The relationship between alveolar oxygen tension and the single-breath carbon monoxide diffusing capacity.

    Science.gov (United States)

    Kanner, R E; Crapo, R O

    1986-04-01

    The effects of alveolar oxygen tension (PAO2) on the single-breath carbon monoxide diffusing capacity (DLCO) were quantified and a factor was derived to accommodate for differences in PAO2 over commonly encountered altitudes and/or varying concentrations of oxygen in the test gas mixture (FIO2) We performed duplicate measurements of DLCO in 7 normal subjects with 6 different oxygen fractions (0.176, 0.196, 0.211, 0.22, 0.25, and 0.27). The PAO2 for each test was measured as the PO2 in the alveolar gas sample bag. DLCO varied inversely with PAO2 and changed by 0.35% for each mmHg change in PAO2 (r = -0.62, p less than 0.001). At an FIO2 of 0.25, PAO2 varied between subjects and was highly correlated with each subject's residual volume to total lung capacity ratio (r = -0.84, p less than 0.001). We suggest that laboratories can adjust the measured DLCO when PAO2 is not congruent to 120 mmHg by the following formula: DLCO (corrected = DLCO (measured) x [1.0 + 0.0035 (PAO2 - 120)].

  17. Enhanced proliferation and dopaminergic differentiation of ventral mesencephalic precursor cells by synergistic effect of FGF2 and reduced oxygen tension

    DEFF Research Database (Denmark)

    Jensen, Pia; Gramsbergen, Jan-Bert; Zimmer, Jens

    2011-01-01

    Effective numerical expansion of dopaminergic precursors might overcome the limited availability of transplantable cells in replacement strategies for Parkinson's disease. Here we investigated the effect of fibroblast growth factor-2 (FGF2) and FGF8 on expansion and dopaminergic differentiation o...... enzyme activity, which may explain the elevated dopamine levels. Our findings demonstrate that modulation of oxygen tension is a recognizable factor for in vitro expansion and dopaminergic differentiation of rat embryonic midbrain precursor cells....... of rat embryonic ventral mesencephalic neuroblasts cultured at high (20%) and low (3%) oxygen tension. More cells incorporated bromodeoxyuridine in cultures expanded at low as compared to high oxygen tension, and after 6 days of differentiation there were significantly more neuronal cells in low than......, switching FGF2-expanded cultures from low to high oxygen tension during the last two days of differentiation significantly enhanced dopamine release and intracellular dopamine levels as compared to all other treatment groups. In addition, the short-term exposure to high oxygen enhanced in situ assessed TH...

  18. Near-simultaneous hemoglobin saturation and oxygen tension maps in mouse brain using an AOTF microscope.

    Science.gov (United States)

    Shonat, R D; Wachman, E S; Niu, W; Koretsky, A P; Farkas, D L

    1997-09-01

    A newly developed microscope using acousto-optic tunable filters (AOTFs) was used to generate in vivo hemoglobin saturation (SO2) and oxygen tension (PO2) maps in the cerebral cortex of mice. SO2 maps were generated from the spectral analysis of reflected absorbance images collected at different wavelengths, and PO2 maps were generated from the phosphorescence lifetimes of an injected palladium-porphyrin compound using a frequency-domain measurement. As the inspiratory O2 was stepped from hypoxia (10% O2), through normoxia (21% O2), to hyperoxia (60% O2), measured SO2 and PO2 levels rose accordingly and predictably throughout. A plot of SO2 versus PO2 in different arterial and venous regions of the pial vessels conformed to the sigmoidal shape of the oxygen-hemoglobin dissociation curve, providing further validation of the two mapping procedures. The study demonstrates the versatility of the AOTF microscope for in vivo physiologic investigation, allowing for the generation of nearly simultaneous SO2 and PO2 maps in the cerebral cortex, and the frequency-domain detection of phosphorescence lifetimes. This class of study opens up exciting new possibilities for investigating the dynamics of hemoglobin and O2 binding during functional activation of neuronal tissues.

  19. Effect of low oxygen tension on the biological characteristics of human bone marrow mesenchymal stem cells.

    Science.gov (United States)

    Kim, Dae Seong; Ko, Young Jong; Lee, Myoung Woo; Park, Hyun Jin; Park, Yoo Jin; Kim, Dong-Ik; Sung, Ki Woong; Koo, Hong Hoe; Yoo, Keon Hee

    2016-11-01

    Culture of mesenchymal stem cells (MSCs) under ambient conditions does not replicate the low oxygen environment of normal physiological or pathological states and can result in cellular impairment during culture. To overcome these limitations, we explored the effect of hypoxia (1 % O 2 ) on the biological characteristics of MSCs over the course of different culture periods. The following biological characteristics were examined in human bone marrow-derived MSCs cultured under hypoxia for 8 weeks: proliferation rate, morphology, cell size, senescence, immunophenotypic characteristics, and the expression levels of stemness-associated factors and cytokine and chemokine genes. MSCs cultured under hypoxia for approximately 2 weeks showed increased proliferation and viability. During long-term culture, hypoxia delayed phenotypic changes in MSCs, such as increased cell volume, altered morphology, and the expression of senescence-associated-β-gal, without altering their characteristic immunophenotypic characteristics. Furthermore, hypoxia increased the expression of stemness and chemokine-related genes, including OCT4 and CXCR7, and did not decrease the expression of KLF4, C-MYC, CCL2, CXCL9, CXCL10, and CXCR4 compared with levels in cells cultured under normoxia. In conclusion, low oxygen tension improved the biological characteristics of MSCs during ex vivo expansion. These data suggest that hypoxic culture could be a useful method for increasing the efficacy of MSC cell therapies.

  20. Exogenous and endogenous angiotensin-II decrease renal cortical oxygen tension in conscious rats by limiting renal blood flow

    NARCIS (Netherlands)

    Emans, Tonja W.; Janssen, Ben J.; Pinkham, Maximilian I.; Ow, Connie P. C.; Evans, Roger G.; Joles, Jaap A.; Malpas, Simon C.; Krediet, C. T. Paul; Koeners, Maarten P.

    2016-01-01

    Our understanding of the mechanisms underlying the role of hypoxia in the initiation and progression of renal disease remains rudimentary. We have developed a method that allows wireless measurement of renal tissue oxygen tension in unrestrained rats. This method provides stable and continuous

  1. BIOELECTRIC POTENTIALS IN HALICYSTIS : VII. THE EFFECTS OF LOW OXYGEN TENSION.

    Science.gov (United States)

    Blinks, L R; Darsie, M L; Skow, R K

    1938-11-20

    The potential difference across the protoplasm of impaled cells of Halicystis is not affected by increase of oxygen tension in equilibrium with the sea water, nor with decrease down to about 1/10 its tension in the air (2 per cent O(2) in N(2)). When bubbling of 2 per cent O(2) is stopped, the P.D. drifts downward, to be restored on stirring the sea water, or rebubbling the gas. Bubbling 0.2 per cent O(2) causes the P.D. to drop to 20 mv. or less; 1.1 per cent O(2) to about 50 mv. Restoration of 2 per cent or higher O(2) causes recovery to 70 or 80 mv. often with a preliminary cusp which decreases the P.D. before it rises. Perfusion of aerated sea water through the vacuole is just as effective in restoring the P.D. as external aeration, indicating that the direction of the oxygen gradient is not significant. Low O(2) tension also inhibits the reversed, negative P.D. produced by adding NH(4)Cl to sea water, 0.2 per cent O(2) bringing this P.D. back to the same low positive values found without ammonia. Restoration of 2 per cent O(2) or air, restores this latent negativity. At slightly below the threshold for ammonia reversal, low O(2) may induce a temporary negativity when first bubbled, and a negative cusp may occur on aeration before positive P.D. is regained. This may be due to a decreased consumption of ammonia, or to intermediate pH changes. The locus of the P.D. alteration was tested by applying increased KCl concentrations to the cell exterior; the large cusps produced in aerated solutions become greatly decreased when the P.D. has fallen in 0.2 per cent O(2). This indicates that the originally high relative mobility or concentration of K(+) ion has approached that of Na(+) in the external protoplasmic surface under reduced O(2) tension. Results obtained with sulfate sea water indicate that Na(+) mobility approaches that of SO(4) (-) in 0.2 per cent O(2). P.D. measurements alone cannot tell whether this is due to an increase of the slower ion or a decrease of

  2. Oxygen Exposure Resulting in Arterial Oxygen Tensions Above the Protocol Goal Was Associated With Worse Clinical Outcomes in Acute Respiratory Distress Syndrome.

    Science.gov (United States)

    Aggarwal, Neil R; Brower, Roy G; Hager, David N; Thompson, B Taylor; Netzer, Giora; Shanholtz, Carl; Lagakos, Adrian; Checkley, William

    2018-04-01

    High fractions of inspired oxygen may augment lung damage to exacerbate lung injury in patients with acute respiratory distress syndrome. Participants enrolled in Acute Respiratory Distress Syndrome Network trials had a goal partial pressure of oxygen in arterial blood range of 55-80 mm Hg, yet the effect of oxygen exposure above this arterial oxygen tension range on clinical outcomes is unknown. We sought to determine if oxygen exposure that resulted in a partial pressure of oxygen in arterial blood above goal (> 80 mm Hg) was associated with worse outcomes in patients with acute respiratory distress syndrome. Longitudinal analysis of data collected in these trials. Ten clinical trials conducted at Acute Respiratory Distress Syndrome Network hospitals between 1996 and 2013. Critically ill patients with acute respiratory distress syndrome. None. We defined above goal oxygen exposure as the difference between the fraction of inspired oxygen and 0.5 whenever the fraction of inspired oxygen was above 0.5 and when the partial pressure of oxygen in arterial blood was above 80 mm Hg. We then summed above goal oxygen exposures in the first five days to calculate a cumulative above goal oxygen exposure. We determined the effect of a cumulative 5-day above goal oxygen exposure on mortality prior to discharge home at 90 days. Among 2,994 participants (mean age, 51.3 yr; 54% male) with a study-entry partial pressure of oxygen in arterial blood/fraction of inspired oxygen that met acute respiratory distress syndrome criteria, average cumulative above goal oxygen exposure was 0.24 fraction of inspired oxygen-days (interquartile range, 0-0.38). Participants with above goal oxygen exposure were more likely to die (adjusted interquartile range odds ratio, 1.20; 95% CI, 1.11-1.31) and have lower ventilator-free days (adjusted interquartile range mean difference of -0.83; 95% CI, -1.18 to -0.48) and lower hospital-free days (adjusted interquartile range mean difference of -1.38; 95

  3. A novel, non-invasive diagnostic clinical procedure for the determination of an oxygenation status of chronic lower leg ulcers using peri-ulceral transcutaneous oxygen partial pressure measurements: results of its application in chronic venous insufficiency (CVI).

    Science.gov (United States)

    Barnikol, Wolfgang K R; Pötzschke, Harald

    2012-01-01

    The basis for the new procedure is the simultaneous transcutaneous measurement of the peri-ulceral oxygen partial pressure (tcPO(2)), using a minimum of 4 electrodes which are placed as close to the wound margin as possible, additionally, as a challenge the patient inhales pure oxygen for approximately 15 minutes. In order to evaluate the measurement data and to characterise the wounds, two new oxygen parameters were defined: (1) the oxygen characteristic (K-PO(2)), and (2) the oxygen inhomogeneity (I-PO(2)) of a chronic wound. The first of these is the arithmetic mean of the two lowest tcPO(2) measurement values, and the second is the variation coefficient of the four measurement values. Using the K-PO(2) parameter, a grading of wound hypoxia can be obtained. To begin with, the physiologically regulated (and still compensated) hypoxia with K-PO(2) values of between 35 and 40 mmHg is distinguished from the pathological decompensated hypoxia with K-PO(2) values of between 0 and 35 mmHg; the first of these still stimulates self-healing (within the limits of the oxygen balance). The decompensated hypoxia can be (arbitrarily) divided into "simple" hypoxia (Grade I), intense hypoxia (Grade II) and extreme hypoxia (Grade III), with the possibility of intermediate grades (I/II and II/III).Measurements were carried out using the new procedure on the skin of the right inner ankle of 21 healthy volunteers of various ages, and in 17 CVI (chronic venous insufficiency) wounds. Sixteen of the 17 CVI wounds (i.e., 94%) were found to be pathologically hypoxic, a state which was not found in any of the healthy volunteers. The oxygen inhomogeneity (I-PO(2)) of the individual chronic wounds increased exponentially as a function of the hypoxia grading (K-PO(2)), with a 10-fold increase with extreme hypoxia in contrast to a constant value of approximately 14% in the healthy volunteers. This pronounced oxygen inhomogeneity explains inhomogeneous wound healing, resulting in the so

  4. Measuring oxygen tension modulation, induced by a new pre-radiotherapy therapeutic, in a mammary window chamber mouse model

    Science.gov (United States)

    Schafer, Rachel; Gmitro, Arthur F.

    2015-03-01

    Tumor regions under hypoxic or low oxygen conditions respond less effectively to many treatment strategies, including radiation therapy. A novel investigational therapeutic, NVX-108 (NuvOx Pharma), has been developed to increase delivery of oxygen through the use of a nano-emulsion of dodecofluoropentane. By raising pO2 levels prior to delivering radiation, treatment efficacy may be improved. To aid in evaluating the novel drug, oxygen tension was quantitatively measured, spatially and temporally, to record the effect of administrating NVX-108 in an orthotopic mammary window chamber mouse model of breast cancer. The oxygen tension was measured through the use of an oxygen-sensitive coating, comprised of phosphorescent platinum porphyrin dye embedded in a polystyrene matrix. The coating, applied to the surface of the coverslip of the window chamber through spin coating, is placed in contact with the mammary fat pad to record the oxygenation status of the surface tissue layer. Prior to implantation of the window chamber, a tumor is grown in the SCID mouse model by injection of MCF-7 cells into the mammary fat pad. Two-dimensional spatial distributions of the pO2 levels were obtained through conversion of measured maps of phosphorescent lifetime. The resulting information on the spatial and temporal variation of the induced oxygen modulation could provide valuable insight into the optimal timing between administration of NVX-108 and radiation treatment to provide the most effective treatment outcome.

  5. Increase of tumor oxygen tension and potentiation of radiation effects using pentoxifylline, vinpocetine and ticlopidine hydrochloride

    International Nuclear Information System (INIS)

    Amano, Morikazu; Monzen, Hajime; Suzuki, Takatoshi; Hasegawa, Takeo

    2004-01-01

    The effects of pentoxifylline (PTX), vinpocetine (VPT) and ticlopidine hydrochloride (TCD), each drug commonly used for vascular disorders in humans, on the pO 2 in SCC-7 (squamous cell carcinoma) tumors of C3H/HeJ mice on the radioresponse of SCC-7 tumors were investigated. When the SCC-7 implanted in the leg of C3H/HeJ mice grew about 100 mm 3 , the effects of PTX, VPT and TCD on the increase oxygen tension in the tumor was determined with polarography. The mice were injected intraperitoneally (ip) with 5 ml/kg PTX, 5 ml/kg VPT, or 10 ml/kg TCD, the tumor pO 2 increased slowly, peaked about 20-50 min postinjection, and returned to its original level in 60-80 min. When the C3H/HeJ mice bearing SCC-7 tumors in the legs were injected ip with 5 ml/kg PTX, 5 ml/kg VPT or 10 ml/kg TCD and tumors were X-irradiated 30 min later, the radiation induced growth delay of the tumor was greater than that caused by X-irradiation alone. The results in the present study, PTX, VPT and TCD increase the tumor pO 2 in rodent tumors strongly suggest that each drug may be useful for increasing the radiosensitivity of human tumor. (author)

  6. Localized increase of tissue oxygen tension by magnetic targeted drug delivery

    Science.gov (United States)

    Liong, Celine; Ortiz, Daniel; Ao-ieong, Eilleen; Navati, Mahantesh S.; Friedman, Joel M.; Cabrales, Pedro

    2014-07-01

    Hypoxia is the major hindrance to successful radiation therapy of tumors. Attempts to increase the oxygen (O2) tension (PO2) of tissue by delivering more O2 have been clinically disappointing, largely due to the way O2 is transported and released by the hemoglobin (Hb) within the red blood cells (RBCs). Systemic manipulation of O2 transport increases vascular resistance due to metabolic autoregulation of blood flow to prevent over oxygenation. This study investigates a new technology to increase O2 delivery to a target tissue by decreasing the Hb-O2 affinity of the blood circulating within the targeted tissue. As the Hb-O2 affinity decreases, the tissue PO2 to satisfy tissue O2 metabolic needs increases without increasing O2 delivery or extraction. Paramagnetic nanoparticles (PMNPs), synthetized using gadolinium oxide, were coated with the cell permeable Hb allosteric effector L35 (3,5-trichlorophenylureido-phenoxy-methylpropionic acid). L35 decreases Hb affinity for O2 and favors the release of O2. The L35-coated PMNPs (L35-PMNPs) were intravenously infused (10 mg kg-1) to hamsters instrumented with the dorsal window chamber model. A magnetic field of 3 mT was applied to localize the effects of the L35-PMNPs to the window chamber. Systemic O2 transport characteristics and microvascular tissue oxygenation were measured after administration of L35-PMNPs with and without magnetic field. The tissue PO2 in untreated control animals was 25.2 mmHg. L35-PMNPs without magnetic field decreased tissue PO2 to 23.4 mmHg, increased blood pressure, and reduced blood flow, largely due to systemic modification of Hb-O2 affinity. L35-PMNPs with magnetic field increased tissue PO2 to 27.9 mmHg, without systemic or microhemodynamic changes. These results indicate that localized modification of Hb-O2 affinity can increase PO2 of target tissue without affecting systemic O2 delivery or triggering O2 autoregulation mechanisms. This technology can be used to treat local hypoxia and to

  7. Characterization and validation of noninvasive oxygen tension measurements in human glioma xenografts by 19F-MR relaxometry

    International Nuclear Information System (INIS)

    Sanden, Boudewijn P.J. van der; Heerschap, Arend; Simonetti, Arjan W.; Rijken, Paul F.J.W.; Peters, Hans P.W.; Stbeen, Georg; Kogel, Albert J. van der

    1999-01-01

    Purpose: The aim of this study was to characterize and to validate noninvasive 19 F-magnetic resonance relaxometry for the measurement of oxygen tensions in human glioma xenografts in nude mice. The following three questions were addressed: 1. When perfluorocarbon compounds (PFCs) are administrated intravenously, which tumor regions are assessed by 19 F-MR relaxometry? 2. Are oxygen tension as detected by 19 F-MR relaxometry (pO 2/relaxo ) comparable to Eppendorf O 2 -electrode measurements (pO 2/electrode )? 3. Can 19 F-MR relaxometry be used to detect oxygen tension changes in tumor tissue during carbogen breathing? Methods and Materials: Slice-selective 19 F-MR relaxometry was carried out with perfluoro-15-crown-5-ether as oxygen sensor. The PFC was injected i.v. 3 days before the 19 F-MR experiments. Two datasets were acquired before and two after the start of carbogen breathing. The distribution of PFCs and necrotic areas were analyzed in 19 F-Spin Echo (SE) density MR images and T 2 -weighted 1 H-SE MR images, respectively. One day after the MR investigations, oxygen tensions were measured by oxygen electrodes in the same slice along two perpendicular tracks. These measurements were followed by (immuno)histochemical analysis of the 2D distribution of perfused microvessels, hypoxic cells, necrotic areas, and macrophages. Results: The PFCs mainly became sequestered in perfused regions at the tumor periphery; thus, 19 F-MR relaxometry probed mean oxygen tensions in these regions throughout the selected MR slice. In perfused regions of the tumor, mean pO 2/relaxo values were comparable to mean pO 2/electrode values, and varied from 0.03 to 9 mmHg. Median pO 2/electrode values of both tracks were lower than mean pO 2/relaxo values, because low pO 2/electrode values that originate from hypoxic and necrotic areas were also included in calculations of median pO 2/electrode values. After 8-min carbogen breathing, the average pO 2/relaxo increase was 3.3 ± 0.8 (SEM

  8. Development of bovine embryos cultured in CR1aa and IVD101 media using different oxygen tensions and culture systems.

    Science.gov (United States)

    Somfai, Tamás; Inaba, Yasushi; Aikawa, Yoshio; Ohtake, Masaki; Kobayashi, Shuji; Konishi, Kazuyuki; Nagai, Takashi; Imai, Kei

    2010-12-01

    The aim of the present study was to optimise the culture conditions for the in vitro production of bovine embryos. The development of in vitro fertilised bovine oocytes in CR1aa supplemented with 5% calf serum and IVD101 culture media were compared using traditional microdrops and Well of the Well (WOW) culture systems either under 5% or 20% oxygen tension. After 7 days of culture, a significantly higher blastocyst formation rate was obtained for embryos cultured in CR1aa medium compared to those cultured in IVD101, irrespective of O2 tensions and culture systems. The blastocyst formation in IVD101 was suppressed under 20% O2 compared to 5% O2 . Despite their similar total cell numbers, higher rates of inner cell mass (ICM) cells were observed in blastocysts developed in IVD101 medium than in those developed in CR1aa, irrespective of O2 tensions. There was no significant difference in blastocyst formation, total, ICM and trophectoderm (TE) cell numbers between embryos obtained by microdrop and WOW culture systems irrespective of the culture media and O2 tensions used. In conclusion, CR1aa resulted in higher blastocyst formation rates irrespective of O2 tension, whereas IVD101 supported blastocyst formation only under low O2 levels but enhanced the proliferation of ICM cells.

  9. Postnatal follow-up of the oxygenation index, arterial to alveolar oxygen tension ratio and alveolar arterial oxygen tension difference values in neonates with the respiratory distress syndrome treated with conventional ventilatory support.

    Science.gov (United States)

    Atanasov, A; Despotova-Toleva, L

    1997-01-01

    Recent development of sophisticated intensive care technique for use in newborn infants with the respiratory distress syndrome (RDS) has resulted in changes in the therapeutic strategies and moved the problem of neonatal survival into the realm of new therapeutic realities. At present, the mechanical ventilation methods form an integral part of the intensive care strategy of infants with RDS. They have come to the forefront of infant care because of their successful use in ventilatory support and children survival where other therapeutic modalities have failed. The present prospective observational longitudinal study was designed to assess the real-time convenience, reliability and accuracy of the changes in the oxygenation index (OI), arterial-to-alveolar oxygen tension ratio (a/A PO2) and alveolar-arterial oxygen gradient (A-a)DO2 in ventilator-dependent neonates with RDS, to analyze their feasibility and potential information yield in oxygen inhalation therapy as well as their prognostic implications and predictive value. Twenty neonates with RDS, heralded by respiratory failure which necessitated the initiation of oxygen inhalation therapy and ventilatory support within 24 hours of birth, were enrolled in the study. Ten of the infants survived and the remaining ten died. OI, (a/A PO2) and (A-a)DO2 were followed up sequentially and thoroughly analyzed as the primary outcome measures of the study. The indices were calculated on the basis of the complete monitoring of the ventilatory equipment parameters and acid-base status carried out on an hourly basis. Our results show that: 1. The combination of three indexes (OI, (a/A)PO2 and (A-a)DO2 we propose is a useful discriminating predictor of neonatal lung maturity reflecting arterial blood gas status in ventilator-dependent neonates with RDS. 2. The indices detect the efficacy of the modern conventional ventilatory support with real-time convenience and reliable accuracy forming the cornerstone of clinical decision

  10. Unusual Growth Phase and Oxygen Tension Regulation of Oxidative Stress Protection Enzymes, Catalase and Superoxide Dismutase, in the Phytopathogen Xanthomonas oryzae pv. oryzae

    OpenAIRE

    Chamnongpol, S.; Mongkolsuk, S.; Vattanaviboon, P.; Fuangthong, M.

    1995-01-01

    The enzymes catalase and superoxide dismutase play major roles in protecting phytopathogenic bacteria from oxidative stress. In Xanthomonas species, these enzymes are regulated by both growth phase and oxygen tension. The highest enzyme levels were detected within 1 h of growth. Continued growth resulted in a decline of both enzyme activities. High oxygen tension was an inducing signal for both enzyme activities. An 80,000-Da monofunctional catalase and a manganese superoxide dismutase were t...

  11. Modelling of L-valine Repeated Fed-batch Fermentation Process Taking into Account the Dissolved Oxygen Tension

    Directory of Open Access Journals (Sweden)

    Tzanko Georgiev

    2009-03-01

    Full Text Available This article deals with synthesis of dynamic unstructured model of variable volume fed-batch fermentation process with intensive droppings for L-valine production. The presented approach of the investigation includes the following main procedures: description of the process by generalized stoichiometric equations; preliminary data processing and calculation of specific rates for main kinetic variables; identification of the specific rates takes into account the dissolved oxygen tension; establishment and optimisation of dynamic model of the process; simulation researches. MATLAB is used as a research environment.

  12. The role of tissue oxygen tension in the control of local blood flow in the microcirculation of skeletal muscles

    DEFF Research Database (Denmark)

    Ngo, Thuc Anh

    2010-01-01

    In the microcirculation blood flow is highly regulated dependent on the metabolic activity of the tissues. Among several mechanisms, mechanisms involved in the coupling of changes in tissue oxygen tension due to changes in the metabolic activity of the tissue play an important role. In the systemic...... (inhibitor of KATP channels) in the superfusate abolished both vasodilatation and constriction to low and high oxygen superfusate, indicating that KATP channels are involved in both hypoxic vasodilatation and hyperoxic vasoconstriction. Red blood cells (RBCs) have been proposed to release ATP and...... as in the intact blood-perfused arteriole. This indicates that RBCs are not essential for hypoxic vasodilatation. In addition several potential pathways were evaluated. Application of DPCPX (inhibitor of adenosine A1 and A2 receptors) and L-NAME (inhibitor of NO-synthase) did not affect vasomotor responses to low...

  13. The effect of oxygen tension on porcine embryonic development is dependent on embryo type

    DEFF Research Database (Denmark)

    Booth, Paul; Holm, Peter; Callesen, Henrik

    2005-01-01

    of the embryos prior to culture--a study was performed to examine the effect of O2 tension during culture on three different types of porcine embryos, namely: in vivo flushed embryos, and in vitro matured oocytes either fertilized in vitro or parthenogenetically activated. In vivo embryos (n=208) were flushed...... supplemented with 10% calf serum until day 7. The gas environment for IVM/IVF was 5% CO2 in air, while that for IVC was either 5% CO2 in air or 5% O2, 5% CO2 and 90% N2. Low O2 tension increased both day 7 blastocyst rates (high versus low O2, respectively; 9.3+/-2.9%: 26/280; 23.9+/-4.2%: 71/293; P...

  14. Discrepancies between measured changes of radiobiological hypoxic fraction and oxygen tension monitoring using two assay systems

    International Nuclear Information System (INIS)

    Sasai, K.; Brown, J.M.

    1994-01-01

    This study was conducted to assess the ability of computerized pO 2 histography to measure changes in tumor oxygenation produced by low oxygen breathing. Female syngeneic C3H/Km mice bearing SCC VII/St carcinomas were used in these experiments. Changes in tumor oxygenation produced by the mice breathing 10% oxygen were assessed with computerized pO2 histography, 3 H-misonidazole binding, and the paired survival curve assay of radiosensitivity. The hypoxic cell fraction of the tumors in mice breathing 10% oxygen was 3.1 times higher than that of tumors in mice breathing normal air determined by an in vivo-in vitro clonogenic assay. Binding of radiolabeled misonidazole to the tumors in mice breathing 10% oxygen was also significantly higher than that to tumors in mice breathing normal air (p 2 value for the tumor. The number of pO 2 readings lower than 5 mmHg in the tumor was not affected by the 10% oxygen breathing. These findings indicate that increases in radiobiological hypoxic fraction produced by lower blood oxygen levels may not correlate well with the results of polarographic measurements of tumor pO 2 levels. 29 refs., 4 figs., 1 tab

  15. Comparison of Preterm and Term Wharton's Jelly-Derived Mesenchymal Stem Cell Properties in Different Oxygen Tensions.

    Science.gov (United States)

    Balgi-Agarwal, Saloni; Winter, Caitlyn; Corral, Alexis; Mustafa, Shamimunisa B; Hornsby, Peter; Moreira, Alvaro

    2018-06-27

    Mesenchymal stem cells (MSCs) have shown promise as therapeutic agents in treating morbidities associated with premature birth. MSCs derived from the human umbilical cord are easy to isolate and have low immunogenicity and a robust ability to secrete paracrine factors. To date, there are no studies evaluating preterm versus term umbilical cord tissue-derived MSCs. Therefore, our aim was twofold: (1) to compare stem cell properties in preterm versus term MSCs and (2) to examine the impact of oxygen tension on stem cell behavior. Umbilical cord tissue was obtained from 5 preterm and 5 term neonates. The cells were isolated and characterized as MSCs in accordance with the International Society for Cellular Therapy. We exposed MSCs to different oxygen tensions to examine the impact of environmental factors on cell performance. We studied the following stem cell properties: (i) motility, (ii) proliferation, (iii) senescence, (iv) cell viability, (v) colony-forming unit efficiency, and (vi) inflammatory cytokine expression. Under normoxia (21% O2), cells from preterm and term infants had similar properties. Under hypoxic conditions (1% O2), term MSCs had better cell proliferation; however, cells exposed to hyperoxia (90% O2) had the slowest motility and lowest cell viability (p cytokine expression between the groups. The term cells demonstrated more colony-forming efficiency than the preterm cells. In sum, our preliminary findings suggest that MSCs derived from term and preterm umbilical cords have similar characteristics, offering the potential of future autologous/allogeneic MSC transplants in neonates. © 2018 S. Karger AG, Basel.

  16. Detection of cerebral arterial gas embolism using regional cerebral oxygen saturation, quantitative electroencephalography, and brain oxygen tension in the swine

    NARCIS (Netherlands)

    Weenink, R. P.; Hollmann, M. W.; Stevens, M. F.; Kager, J.; van Gulik, T. M.; van Hulst, R. A.

    2014-01-01

    Cerebral air emboli occur as a complication of invasive medical procedures. The sensitivity of cerebral monitoring methods for the detection of air emboli is not known. This study investigates the utility of electroencephalography and non-invasively measured cerebral oxygen saturation in the

  17. Exogenous and endogenous angiotensin-II decrease renal cortical oxygen tension in conscious rats by limiting renal blood flow.

    Science.gov (United States)

    Emans, Tonja W; Janssen, Ben J; Pinkham, Maximilian I; Ow, Connie P C; Evans, Roger G; Joles, Jaap A; Malpas, Simon C; Krediet, C T Paul; Koeners, Maarten P

    2016-11-01

    Our understanding of the mechanisms underlying the role of hypoxia in the initiation and progression of renal disease remains rudimentary. We have developed a method that allows wireless measurement of renal tissue oxygen tension in unrestrained rats. This method provides stable and continuous measurements of cortical tissue oxygen tension (PO2) for more than 2 weeks and can reproducibly detect acute changes in cortical oxygenation. Exogenous angiotensin-II reduced renal cortical tissue PO2 more than equi-pressor doses of phenylephrine, probably because it reduced renal oxygen delivery more than did phenylephrine. Activation of the endogenous renin-angiotensin system in transgenic Cyp1a1Ren2 rats reduced cortical tissue PO2; in this model renal hypoxia precedes the development of structural pathology and can be reversed acutely by an angiotensin-II receptor type 1 antagonist. Angiotensin-II promotes renal hypoxia, which may in turn contribute to its pathological effects during development of chronic kidney disease. We hypothesised that both exogenous and endogenous angiotensin-II (AngII) can decrease the partial pressure of oxygen (PO2) in the renal cortex of unrestrained rats, which might in turn contribute to the progression of chronic kidney disease. Rats were instrumented with telemeters equipped with a carbon paste electrode for continuous measurement of renal cortical tissue PO2. The method reproducibly detected acute changes in cortical oxygenation induced by systemic hyperoxia and hypoxia. In conscious rats, renal cortical PO2 was dose-dependently reduced by intravenous AngII. Reductions in PO2 were significantly greater than those induced by equi-pressor doses of phenylephrine. In anaesthetised rats, renal oxygen consumption was not affected, and filtration fraction was increased only in the AngII infused animals. Oxygen delivery decreased by 50% after infusion of AngII and renal blood flow (RBF) fell by 3.3 ml min -1 . Equi-pressor infusion of

  18. Exogenous and endogenous angiotensin‐II decrease renal cortical oxygen tension in conscious rats by limiting renal blood flow

    Science.gov (United States)

    Emans, Tonja W.; Janssen, Ben J.; Pinkham, Maximilian I.; Ow, Connie P. C.; Evans, Roger G.; Joles, Jaap A.; Malpas, Simon C.; Krediet, C. T. Paul

    2016-01-01

    Key points Our understanding of the mechanisms underlying the role of hypoxia in the initiation and progression of renal disease remains rudimentary.We have developed a method that allows wireless measurement of renal tissue oxygen tension in unrestrained rats.This method provides stable and continuous measurements of cortical tissue oxygen tension (PO2) for more than 2 weeks and can reproducibly detect acute changes in cortical oxygenation.Exogenous angiotensin‐II reduced renal cortical tissue PO2 more than equi‐pressor doses of phenylephrine, probably because it reduced renal oxygen delivery more than did phenylephrine.Activation of the endogenous renin–angiotensin system in transgenic Cyp1a1Ren2 rats reduced cortical tissue PO2; in this model renal hypoxia precedes the development of structural pathology and can be reversed acutely by an angiotensin‐II receptor type 1 antagonist.Angiotensin‐II promotes renal hypoxia, which may in turn contribute to its pathological effects during development of chronic kidney disease. Abstract We hypothesised that both exogenous and endogenous angiotensin‐II (AngII) can decrease the partial pressure of oxygen (PO2) in the renal cortex of unrestrained rats, which might in turn contribute to the progression of chronic kidney disease. Rats were instrumented with telemeters equipped with a carbon paste electrode for continuous measurement of renal cortical tissue PO2. The method reproducibly detected acute changes in cortical oxygenation induced by systemic hyperoxia and hypoxia. In conscious rats, renal cortical PO2 was dose‐dependently reduced by intravenous AngII. Reductions in PO2 were significantly greater than those induced by equi‐pressor doses of phenylephrine. In anaesthetised rats, renal oxygen consumption was not affected, and filtration fraction was increased only in the AngII infused animals. Oxygen delivery decreased by 50% after infusion of AngII and renal blood flow (RBF) fell by 3.3 ml min−1

  19. Cutaneous respirometry by dynamic measurement of mitochondrial oxygen tension for monitoring mitochondrial function in vivo.

    Science.gov (United States)

    Harms, Floor A; Voorbeijtel, Wilhelmina J; Bodmer, Sander I A; Raat, Nicolaas J H; Mik, Egbert G

    2013-09-01

    Progress in diagnosis and treatment of mitochondrial dysfunction in chronic and acute disease could greatly benefit from techniques for monitoring of mitochondrial function in vivo. In this study we demonstrate the feasibility of in vivo respirometry in skin. Mitochondrial oxygen measurements by means of oxygen-dependent delayed fluorescence of protoporphyrin IX are shown to provide a robust basis for measurement of local oxygen disappearance rate (ODR). The fundamental principles behind the technology are described, together with an analysis method for retrievel of respirometry data. The feasibility and reproducibility of this clinically useful approach are demonstrated in a series of rats. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Membrane culture and reduced oxygen tension enhances cartilage matrix formation from equine cord blood mesenchymal stromal cells in vitro.

    Science.gov (United States)

    Co, C; Vickaryous, M K; Koch, T G

    2014-03-01

    Ongoing research is aimed at increasing cartilage tissue yield and quality from multipotent mesenchymal stromal cells (MSC) for the purpose of treating cartilage damage in horses. Low oxygen culture has been shown to enhance chondrogenesis, and novel membrane culture has been proposed to increase tissue yield and homogeneity. The objective of this study was to evaluate and compare the effect of reduced oxygen and membrane culture during in vitro chondrogenesis of equine cord blood (CB) MSC. CB-MSC (n = 5 foals) were expanded at 21% oxygen prior to 3-week differentiation in membrane or pellet culture at 5% and 21% oxygen. Assessment included histological examination (H&E, toluidine Blue, immunohistochemistry (IHC) for collagen type I and II), protein quantification by hydroxyproline assay and dimethylmethylene assay, and mRNA analysis for collagen IA1, collagen IIA1, collagen XA1, HIF1α and Sox9. Among treatment groups, 5% membrane culture produced neocartilage most closely resembling hyaline cartilage. Membrane culture resulted in increased wet mass, homogenous matrix morphology and an increase in total collagen content, while 5% oxygen culture resulted in higher GAG and type II collagen content. No significant differences were observed for mRNA analysis. Membrane culture at 5% oxygen produces a comparatively larger amount of higher quality neocartilage. Matrix homogeneity is attributed to a uniform diffusion gradient and reduced surface tension. Membrane culture holds promise for scale-up for therapeutic purposes, for cellular preconditioning prior to cytotherapeutic applications, and for modeling system for gas-dependent chondrogenic differentiation studies. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  1. Ion release from magnesium materials in physiological solutions under different oxygen tensions.

    Science.gov (United States)

    Feyerabend, Frank; Drücker, Heiko; Laipple, Daniel; Vogt, Carla; Stekker, Michael; Hort, Norbert; Willumeit, Regine

    2012-01-01

    Although magnesium as degradable biomaterial already showed clinical proof of concepts, the design of new alloys requires predictive in vitro methods, which are still lacking. Incubation under cell culture conditions to obtain "physiological" corrosion may be a solution. The aim of this study was to analyse the influence of different solutions, addition of proteins and of oxygen availability on the corrosion of different magnesium materials (pure Mg, WE43, and E11) with different surface finishing. Oxygen content in solution, pH, osmolality and ion release were determined. Corrosion led to a reduction of oxygen in solution. The influence of oxygen on pH was enhanced by proteins, while osmolality was not influenced. Magnesium ion release was solution-dependent and enhanced in the initial phase by proteins with delayed release of alloying elements. The main corrosion product formed was magnesium carbonate. Therefore, cell culture conditions are proposed as first step toward physiological corrosion.

  2. Comparison Between Cerebral Tissue Oxygen Tension and Energy Metabolism in Experimental Subdural Hematoma

    DEFF Research Database (Denmark)

    Nielsen, Troels Halfeld; Engell, Susanne I; Johnsen, Rikke Aagaard

    2011-01-01

    BACKGROUND: An experimental swine model (n = 7) simulating an acute subdural hematoma (ASDH) was employed (1) to explore the relation between the brain tissue oxygenation (PbtO(2)) and the regional cerebral energy metabolism as obtained by microdialysis, and (2) to define the lowest level of PbtO(2...

  3. Oxygen-tension measurements - The first step towards prevention and early detection of anastomotic leakage

    NARCIS (Netherlands)

    Tanase, D.; French, P.J.; Komen, N.; Kleinrensink, G.J.; Jeekel, J.; Lange, J.F.; Draaijer, A.

    2007-01-01

    Many patients still die every year as a result of anastomotic leakage after surgery. The medical world needs an objective aid to detect leakage during surgery and during the critical recovery period. We propose a miniature measurement system to detect adequate tissue oxygenation pre- and

  4. Influence of hyperoxia on the number of nucleated cells and oxygen tension in rat bone marrow after whole-body irradiation

    International Nuclear Information System (INIS)

    Zima, M.; Vodicka, I.

    1987-01-01

    The cell number in the femur bone marrow of rats determined three days after X-ray or gamma irradiation is inversely proportional to the dose while oxygen tension in the marrow shows direct dependence on the dose. With fractionation of the lethal dose of gamma radiation (9 Gy) into two doses with different time intervals between them, a greater number of bone marrow cells and a smaller oxygen tension are reached on the 3rd day after the second dose, reflecting the extent of bone marrow repair. A short-term hyperoxia (95% O 2 + 5% CO 2 ) lasting 20 min from the end of exposure compared with the euoxic conditions induced, on the 3rd day after the second fraction, a nonsignificant but reproducible increase in the marrow cell number and a decrease in partial oxygen tension in the distal part of femur marrow. The results obtained testify that immediate short-term hyperoxia facilitates regeneration of the marrow and that a greater number of cells accompanied by greater metabolic activity and oxygen consumption decrease the partial oxygen tension measured on the 3rd day following the last exposure. (author). 7 figs., 16 refs

  5. Correlation of cutaneous tension distribution and tissue oxygenation with acute external tissue expansion

    Directory of Open Access Journals (Sweden)

    Marquardt C

    2009-11-01

    Full Text Available Abstract Today, the biomechanical fundamentals of skin expansion are based on viscoelastic models of the skin. Although many studies have been conducted in vitro, analyses performed in vivo are rare. Here, we present in vivo measurements of the expansion at the skin surface as well as measurement of the corresponding intracutaneous oxygen partial pressure. In our study the average skin stretching was 24%, with a standard deviation of 11%, excluding age or gender dependency. The measurement of intracutaneous oxygen partial pressure produced strong inter-individual fluctuations, including initial values at the beginning of the measurement, as well as varying individual patient reactions to expansion of the skin. Taken together, we propose that even large defect wounds can be closed successfully using the mass displacement caused by expansion especially in areas where soft, voluminous tissue layers are present.

  6. Effect of low oxygen tension on the biological characteristics of human bone marrow mesenchymal stem cells

    OpenAIRE

    Kim, Dae Seong; Ko, Young Jong; Lee, Myoung Woo; Park, Hyun Jin; Park, Yoo Jin; Kim, Dong-Ik; Sung, Ki Woong; Koo, Hong Hoe; Yoo, Keon Hee

    2016-01-01

    Culture of mesenchymal stem cells (MSCs) under ambient conditions does not replicate the low oxygen environment of normal physiological or pathological states and can result in cellular impairment during culture. To overcome these limitations, we explored the effect of hypoxia (1 % O2) on the biological characteristics of MSCs over the course of different culture periods. The following biological characteristics were examined in human bone marrow-derived MSCs cultured under hypoxia for 8 week...

  7. Adverse effects of reduced oxygen tension on the proliferative capacity of rat kidney and insulin-secreting cell lines involve DNA damage and stress responses

    International Nuclear Information System (INIS)

    Chen Jianhua; Jones, R. Huw; Tarry-Adkins, Jane; Smith, Noel H.; Ozanne, Susan E.

    2008-01-01

    Standard cell culture conditions do not reflect the physiological environment in terms of oxygen tension (20% vs 3%). The effects of lowering oxygen tension on cell proliferation in culture can be beneficial as well as detrimental depending on the cell line studied, but the molecular mechanism underlying such effects is not fully understood. We observed that the proliferative capacity of the rat cell lines NRK and INS-1 was inhibited when cultured under 3% oxygen as compared to 20% oxygen. Suppression of proliferation in NRK cells was accompanied by induction of DNA double strand breaks whereas in INS-1 cells it was accompanied by up-regulation of p53 and p27. Although Sirt1 was up-regulated in both cell lines by 3% oxygen the effects on antioxidant enzymes (MnSOD, CuZnSOD and catalase) were cell line specific. Marked up-regulation of heme oxygenase-1 (HO-1) was detected in both NRK and INS-1 cells when cultured in 3% oxygen. HO-1 expression can be readily induced by exposure to hydrogen peroxide in culture. These results suggest that reduced oxygen tension suppresses the proliferative capacity of these two cell lines through a stress response that is similar to an oxidative stress response but the molecular events that lead to the reduced cell proliferation are cell line specific

  8. Variations in tumour oxygen tension (pO2) during accelerated radiotherapy of head and neck carcinoma

    International Nuclear Information System (INIS)

    Guichard, M.; Eschwege, F.; Luboinski, B.; Wibault, P.; Weeger, P.; Lusinchi, A.; Lartigau, E.

    1998-01-01

    The study was performed to assess the effect of accelerated radiotherapy on oxygenation of primary tumours and metastatic nodes in patients with advanced head and neck tumours. In 14 patients with head and neck tumour, oxygen tension (pO 2 ) was evaluated in normal tissues and tumours (primary tumour or metastatic neck node) before (0 Gy) and after 2 weeks (32 Gy) of accelerated radiotherapy (70 Gy in 3.5 weeks, with three daily fractions). Radiotherapy was combined with carbogen breathing in 5 patients. pO 2 was measured using a polarographic technique. For pooled normal tissues, median pO 2 was 38 mmHg before treatment and 46 mmHg after 2 weeks. For tumours, very low values ( 2 12 mmHg before treatment versus 26 mmHg after 2 weeks, P 2 was 44 mmHg at 2 weeks, compared with 13.5 mmHg before treatment (P=0.05). Very low pO 2 values, corresponding to tumour hypoxia, were found in the tumours (primary and metastatic neck nodes) prior to accelerated treatment. During the first 2 weeks of accelerated treatment, an increase in median pO 2 was found in nine of the 14 tumours, together with a decrease in the frequency of very low values. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  9. IVF/ICSI outcomes after culture of human embryos at low oxygen tension: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Gomes Sobrinho David B

    2011-11-01

    Full Text Available Abstract Background Improved pregnancy, implantation, and birth rates have been reported after the use of reduced O2 concentration during embryo culture, mainly due to a reduction of the cumulative detrimental effects of reactive oxygen species. However, some studies have failed to report any positive effects. The objective of this meta-analysis was to evaluate the effect of a low-O2 environment on IVF/intracytoplasmic sperm injection (ICSI outcomes. Methods All available published and ongoing randomised trials that compared the effects of low (~5%; OC~5 and atmospheric (~20%; OC~20 oxygen concentrations on IVF/ICSI outcomes were included. Search strategies included online surveys of databases from 1980 to 2011. The outcomes measured were fertilisation rate, implantation rate and ongoing pregnancy rates. The fixed effects model was used to calculate the odds ratio. Results Seven studies were included in this analysis. The pooled fertilisation rate did not differ significantly (P = 0.54 between the group of oocytes cultured at low O2 tension and the group at atmospheric O2 tension. Concerning all cycles, the implantation (P = 0.06 and ongoing pregnancy (P = 0.051 rates were not significantly different between the group receiving transferred sets containing only OC~5 embryos and the group receiving transferred sets with only OC~20 embryos. In a meta-analysis performed for only those trials in which embryos were transferred on day 2/3, implantation (P = 0.63 and ongoing pregnancy (P = 0.19 rates were not significantly different between the groups. In contrast, when a meta-analysis was performed using only trials in which embryos were transferred on days 5 and 6 (at the blastocyst stage, the group with transferred sets of only OC~5 embryos showed a statistically significantly higher implantation rate (P = 0.006 than the group receiving transferred sets with only OC~20 embryos, although the ongoing pregnancy (P = 0.19 rates were not significantly

  10. Endothelial cell respiration is affected by the oxygen tension during shear exposure: role of mitochondrial peroxynitrite.

    Science.gov (United States)

    Jones, Charles I; Han, Zhaosheng; Presley, Tennille; Varadharaj, Saradhadevi; Zweier, Jay L; Ilangovan, Govindasamy; Alevriadou, B Rita

    2008-07-01

    Cultured vascular endothelial cell (EC) exposure to steady laminar shear stress results in peroxynitrite (ONOO(-)) formation intramitochondrially and inactivation of the electron transport chain. We examined whether the "hyperoxic state" of 21% O(2), compared with more physiological O(2) tensions (Po(2)), increases the shear-induced nitric oxide (NO) synthesis and mitochondrial superoxide (O(2)(*-)) generation leading to ONOO(-) formation and suppression of respiration. Electron paramagnetic resonance oximetry was used to measure O(2) consumption rates of bovine aortic ECs sheared (10 dyn/cm(2), 30 min) at 5%, 10%, or 21% O(2) or left static at 5% or 21% O(2). Respiration was inhibited to a greater extent when ECs were sheared at 21% O(2) than at lower Po(2) or left static at different Po(2). Flow in the presence of an endothelial NO synthase (eNOS) inhibitor or a ONOO(-) scavenger abolished the inhibitory effect. EC transfection with an adenovirus that expresses manganese superoxide dismutase in mitochondria, and not a control virus, blocked the inhibitory effect. Intracellular and mitochondrial O(2)(*-) production was higher in ECs sheared at 21% than at 5% O(2), as determined by dihydroethidium and MitoSOX red fluorescence, respectively, and the latter was, at least in part, NO-dependent. Accumulation of NO metabolites in media of ECs sheared at 21% O(2) was modestly increased compared with ECs sheared at lower Po(2), suggesting that eNOS activity may be higher at 21% O(2). Hence, the hyperoxia of in vitro EC flow studies, via increased NO and mitochondrial O(2)(*-) production, leads to enhanced ONOO(-) formation intramitochondrially and suppression of respiration.

  11. Environmental oxygen tension regulates the energy metabolism and self-renewal of human embryonic stem cells.

    Science.gov (United States)

    Forristal, Catherine E; Christensen, David R; Chinnery, Fay E; Petruzzelli, Raffaella; Parry, Kate L; Sanchez-Elsner, Tilman; Houghton, Franchesca D

    2013-01-01

    Energy metabolism is intrinsic to cell viability but surprisingly has been little studied in human embryonic stem cells (hESCs). The current study aims to investigate the effect of environmental O2 tension on carbohydrate utilisation of hESCs. Highly pluripotent hESCs cultured at 5% O2 consumed significantly more glucose, less pyruvate and produced more lactate compared to those maintained at 20% O2. Moreover, hESCs cultured at atmospheric O2 levels expressed significantly less OCT4, SOX2 and NANOG than those maintained at 5% O2. To determine whether this difference in metabolism was a reflection of the pluripotent state, hESCs were cultured at 5% O2 in the absence of FGF2 for 16 hours leading to a significant reduction in the expression of SOX2. In addition, these cells consumed less glucose and produced significantly less lactate compared to those cultured in the presence of FGF2. hESCs maintained at 5% O2 were found to consume significantly less O2 than those cultured in the absence of FGF2, or at 20% O2. GLUT1 expression correlated with glucose consumption and using siRNA and chromatin immunoprecipitation was found to be directly regulated by hypoxia inducible factor (HIF)-2α at 5% O2. In conclusion, highly pluripotent cells associated with hypoxic culture consume low levels of O2, high levels of glucose and produce large amounts of lactate, while at atmospheric conditions glucose consumption and lactate production are reduced and there is an increase in oxidative metabolism. These data suggest that environmental O2 regulates energy metabolism and is intrinsic to the self-renewal of hESCs.

  12. Diet-induced weight loss decreases adipose tissue oxygen tension with parallel changes in adipose tissue phenotype and insulin sensitivity in overweight humans

    NARCIS (Netherlands)

    Vink, R.G.; Roumans, N.J.; Čajlaković, M.; Cleutjens, J.P.M.; Boekschoten, M.V.; Fazelzadeh, P.; Vogel, M.A.A.; Blaak, E.E.; Mariman, E.C.; Baak, van M.A.; Goossens, G.H.

    2017-01-01

    Background/objectives: Although adipose tissue (AT) hypoxia is present in rodent models of obesity, evidence for this in humans is limited. Here, we investigated the effects of diet-induced weight loss (WL) on abdominal subcutaneous AT oxygen tension (pO 2), AT blood flow (ATBF), AT capillary

  13. [transcutaneous oximetry--between theory and practice].

    Science.gov (United States)

    Zulec, Mirna

    2014-10-01

    Transcutaneous oximetry is a procedure used to measure the pressure of oxygen in tissue and to determine oxygenation level. It is essential to determine the state of microcirculation and is used to assess the necessity and level of amputation and the effect of revascularization procedures, as a predictor of wound healing and hyperbaric oxygen therapy (HBOT) effectiveness tool. The measurement is done by the application electrode measuring point and the result is measured in mm Hg. Tissue with adequate oxygen level has a value greater than 50 mm Hg. Values between 20 and 40 mm Hg are considered hypoxic, while those below 20 mm Hg indicate extreme hypoxia. In Croatia, TcPO2 is commonly used for HBOT assessment but there is the need of broader application to objectify and facilitate procedures in the care of persons with impaired microcirculation.

  14. Matrix forming characteristics of inner and outer human meniscus cells on 3D collagen scaffolds under normal and low oxygen tensions.

    Science.gov (United States)

    Croutze, Roger; Jomha, Nadr; Uludag, Hasan; Adesida, Adetola

    2013-12-13

    Limited intrinsic healing potential of the meniscus and a strong correlation between meniscal injury and osteoarthritis have prompted investigation of surgical repair options, including the implantation of functional bioengineered constructs. Cell-based constructs appear promising, however the generation of meniscal constructs is complicated by the presence of diverse cell populations within this heterogeneous tissue and gaps in the information concerning their response to manipulation of oxygen tension during cell culture. Four human lateral menisci were harvested from patients undergoing total knee replacement. Inner and outer meniscal fibrochondrocytes (MFCs) were expanded to passage 3 in growth medium supplemented with basic fibroblast growth factor (FGF-2), then embedded in porous collagen type I scaffolds and chondrogenically stimulated with transforming growth factor β3 (TGF-β3) under 21% (normal or normoxic) or 3% (hypoxic) oxygen tension for 21 days. Following scaffold culture, constructs were analyzed biochemically for glycosaminoglycan production, histologically for deposition of extracellular matrix (ECM), as well as at the molecular level for expression of characteristic mRNA transcripts. Constructs cultured under normal oxygen tension expressed higher levels of collagen type II (p = 0.05), aggrecan (p oxygen tension. There was no significant difference in expression of these genes between scaffolds seeded with MFCs isolated from inner or outer regions of the tissue following 21 days chondrogenic stimulation (p > 0.05). Cells isolated from inner and outer regions of the human meniscus demonstrated equivalent differentiation potential toward chondrogenic phenotype and ECM production. Oxygen tension played a key role in modulating the redifferentiation of meniscal fibrochondrocytes on a 3D collagen scaffold in vitro.

  15. A multislice single breath-hold scheme for imaging alveolar oxygen tension in humans.

    Science.gov (United States)

    Hamedani, Hooman; Kadlecek, Stephen J; Emami, Kiarash; Kuzma, Nicholas N; Xu, Yinan; Xin, Yi; Mongkolwisetwara, Puttisarn; Rajaei, Jennia; Barulic, Amy; Wilson Miller, G; Rossman, Milton; Ishii, Masaru; Rizi, Rahim R

    2012-05-01

    Reliable, noninvasive, and high-resolution imaging of alveolar partial pressure of oxygen (p(A)O(2)) is a potentially valuable tool in the early diagnosis of pulmonary diseases. Several techniques have been proposed for regional measurement of p(A)O(2) based on the increased depolarization rate of hyperpolarized (3) He. In this study, we explore one such technique by applying a multislice p(A)O(2) -imaging scheme that uses interleaved-slice ordering to utilize interslice time-delays more efficiently. This approach addresses the low spatial resolution and long breath-hold requirements of earlier techniques, allowing p(A)O(2) measurements to be made over the entire human lung in 10-15 s with a typical resolution of 8.3 × 8.3 × 15.6 mm(3). PO(2) measurements in a glass syringe phantom were in agreement with independent gas analysis within 4.7 ± 4.1% (R = 0.9993). The technique is demonstrated in four human subjects (healthy nonsmoker, healthy former smoker, healthy smoker, and patient with COPD), each imaged six times on 3 different days during a 2-week span. Two independent measurements were performed in each session, consisting of 12 coronal slices. The overall p(A)O(2) mean across all subjects was 95.9 ± 12.2 Torr and correlated well with end-tidal O(2) (R = 0.805, P < 0.0001). The alveolar O(2) uptake rate was consistent with the expected range of 1-2 Torr/s. Repeatable visual features were observed in p(A)O(2) maps over different days, as were characteristic differences among the subjects and gravity-dependent effects. Copyright © 2011 Wiley Periodicals, Inc.

  16. Critical oxygen tension and the effect of hypoxia on the oxygen consumption of the striped catfish, Pangasius hypophthaimos (Pangasiidae)

    DEFF Research Database (Denmark)

    Lefevre, S.; Bayley, Mark; Wang, Tobias

    2008-01-01

    The striped catfish (Pangasius hypophthalmus) is an air-breathing teleost that uses a modified swim bladder for aerial gas exchange. Pangasius is of enormous importance for aquaculture industry in the Mekong Delta(Vietnam), but little is known about its physiology. We have initiated a series...... consumption (VO2), measured with intermittent closed respirometry, was 67.8 ± 5.1 mLO2/kg/h when the fish were maintained without access to air at 27 °C. The critical oxygen tension (Pcrit) at these conditions was 57.9 ± 8.9 mmHg (N = 7). The metabolic response to aquatic hypoxia was studied in fish subjected....... The ontogenetic effect of environmental PO2 on metabolism is currently under investigation with fish being reared in 30%, 60% and 100% saturation. Data on resting VO2and Pcrit will be presented and discussed for these animals....

  17. Additive influence of extracellular pH, oxygen tension, and pressure on invasiveness and survival of human osteosarcoma cells

    Directory of Open Access Journals (Sweden)

    Takao eMatsubara

    2013-07-01

    Full Text Available BACKGROUND/PURPOSE:The effects of chemical and physical interactions in the microenvironment of solid tumors have not been fully elucidated. We hypothesized that acidosis, hypoxia, and elevated interstitial fluid pressure (eIFP have additive effects on tumor cell biology and lead to more aggressive behavior during tumor progression. We investigated this phenomenon using 3 human osteosarcoma cell lines and a novel in vitro cell culture apparatus. MATERIALS AND METHODS:U2OS, SaOS, and MG63 cell lines were cultured in media adjusted to various pH levels, oxygen tension (hypoxia 2% O2, normoxia 20% O2, and hydrostatic gauge pressure (0 or 50 mm Hg. Growth rate, apoptosis, cell cycle parameters, and expression of mRNA for proteins associated with invasiveness and tumor microenvironment (CA IX, VEGF-A, HIF-1A, MMP-9, and TIMP-2 were analyzed. Levels of CA IX, HIF-1α, and MMP-9 were measured using immunofluorescence. The effect of pH on invasiveness was evaluated in a Matrigel chamber assay.RESULTS: Within the acidic–hypoxic–pressurized conditions that simulate the microenvironment at a tumor’s center, invasive genes were upregulated, but the cell cycle was downregulated. The combined influence of acidosis, hypoxia, and IFP promoted invasiveness and angiogenesis to a greater extent than did pH, pO2, or eIFP individually. Significant cell death after brief exposure to acidic conditions occurred in each cell line during acclimation to acidic media, while prolonged exposure to acidic media resulted in reduced cell death. Furthermore, 48-hour exposure to acidic conditions promoted tumor invasiveness in the Matrigel assay. CONCLUSION: Our findings demonstrate that tumor microenvironmental parameters—particularly pH, pO2, and eIFP—additively influence tumor proliferation, invasion, metabolism, and viability to enhance cell survival.

  18. Optimizing the calculation of DM,CO and VC via the single breath single oxygen tension DLCO/NO method.

    Science.gov (United States)

    Coffman, Kirsten E; Taylor, Bryan J; Carlson, Alex R; Wentz, Robert J; Johnson, Bruce D

    2016-01-15

    Alveolar-capillary membrane conductance (D(M,CO)) and pulmonary-capillary blood volume (V(C)) are calculated via lung diffusing capacity for carbon monoxide (DL(CO)) and nitric oxide (DL(NO)) using the single breath, single oxygen tension (single-FiO2) method. However, two calculation parameters, the reaction rate of carbon monoxide with blood (θ(CO)) and the D(M,NO)/D(M,CO) ratio (α-ratio), are controversial. This study systematically determined optimal θ(CO) and α-ratio values to be used in the single-FiO2 method that yielded the most similar D(M,CO) and V(C) values compared to the 'gold-standard' multiple-FiO2 method. Eleven healthy subjects performed single breath DL(CO)/DL(NO) maneuvers at rest and during exercise. D(M,CO) and V(C) were calculated via the single-FiO2 and multiple-FiO2 methods by implementing seven θ(CO) equations and a range of previously reported α-ratios. The RP θ(CO) equation (Reeves, R.B., Park, H.K., 1992. Respiration Physiology 88 1-21) and an α-ratio of 4.0-4.4 yielded DM,CO and VC values that were most similar between methods. The RP θ(CO) equation and an experimental α-ratio should be used in future studies. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Stimulation of growth of the human gastric pathogen Helicobacter pylori by atmospheric level of oxygen under high carbon dioxide tension

    Directory of Open Access Journals (Sweden)

    Lee Na

    2011-05-01

    Full Text Available Abstract Background Helicobacter pylori (Hp, a human pathogen that is associated with gastritis, peptic ulcer, and gastric cancer, has been considered a microaerophile, but there is no general consensus about its specific O2 requirements. A clear understanding of Hp physiology is needed to elucidate the pathogenic mechanism(s of Hp infection. Results We cultured Hp under a range of O2 levels with or without 10% CO2 and evaluated growth profiles, morphology, intracellular pH, and energy metabolism. We found that, in the presence of 10% CO2, the normal atmospheric level of O2 inhibited Hp growth at low density but stimulated growth at a higher density. Field emission scanning electron microscopy and fluorescence microscopy of Hp cells cultured under 20% O2 tension revealed live spiral-shaped bacteria with outer membrane vesicles on a rugged cell surface, which became smooth during the stationary phase. Fermentation products including acetate, lactate, and succinate were detected in cell culture media grown under microaerobic conditions, but not under the aerobic condition. CO2 deprivation for less than 24 h did not markedly change cytoplasmic or periplasmic pH, suggesting that cellular pH homeostasis alone cannot account for the capnophilic nature of Hp. Further, CO2 deprivation significantly increased intracellular levels of ppGpp and ATP but significantly decreased cellular mRNA levels, suggesting induction of the stringent response. Conclusions We conclude, unlike previous reports, that H. pylori may be a capnophilic aerobe whose growth is promoted by atmospheric oxygen levels in the presence of 10% CO2. Our data also suggest that buffering of intracellular pH alone cannot account for the CO2 requirement of H. pylori and that CO2 deprivation initiates the stringent response in H. pylori. Our findings may provide new insight into the physiology of this fastidious human pathogen.

  20. Oxygen tension in human tumours measured with polarographic needle electrodes and its relationship to vascular density, necrosis and hypoxia

    International Nuclear Information System (INIS)

    Lyng, Heidi; Sundfoer, Kolbein; Rofstad, Einar K.

    1997-01-01

    Background and purpose: The use of polarographic needle electrodes for measurement of oxygen tension (pO 2 ) in tumours requires documentation of the validity of the method. In the present work the pO 2 values measured polarographically with the Eppendorf pO 2 histograph in human tumours were compared with the histological appearance of the tumour tissue, i.e. vascular density, fraction of necrosis and fraction of hypoxic tissue, to investigate whether the measurements reflected the expected pO 2 . Materials and methods: The pO 2 was measured in cervix tumours in patients and in human melanoma xenografted tumours in athymic mice. Vascular density was determined in the cervix tumours by histological analysis of biopsies from the pO 2 measurement tracks. Fraction of necrosis and fraction of hypoxic tissue, i.e. tissue binding the hypoxia marker pimonidazole, were determined in the melanomas by analysis of histological sections from the tumour planes in which the pO 2 measurements were performed. Results: The pO 2 distributions showed large intratumour heterogeneity. In cervix tumours, tumour regions with vascular density (vascular length per unit tissue volume) in the range of 47-77 mm/mm 3 showed higher pO 2 than tumour regions with vascular density in the range of 20-47 mm/mm 3 , which in turn showed higher pO 2 than tumour regions with vascular density in the range of 0-20 mm/mm 3 . In melanomas, tumour regions in which necrosis and hypoxia constituted more than 50% of the tissue showed lower pO 2 than other tumour regions. Conclusions: The pO 2 measured in the tumours was consistent with the histological appearance of the tissue in which the measurements were performed, suggesting that reliable pO 2 distributions of tumours can be obtained with polarographic needle electrodes

  1. Prediction of inspired oxygen fraction for targeted arterial oxygen tension following open heart surgery in non-smoking and smoking patients.

    Science.gov (United States)

    Bou-Khalil, Pierre; Zeineldine, Salah; Chatburn, Robert; Ayyoub, Chakib; Elkhatib, Farouk; Bou-Akl, Imad; El-Khatib, Mohamad

    2017-10-01

    Simple and accurate expressions describing the P a O 2 -F i O 2 relationship in mechanically ventilated patients are lacking. The current study aims to validate a novel mathematical expression for accurate prediction of the fraction of inspired oxygen that will result in a targeted arterial oxygen tension in non-smoking and smoking patients receiving mechanical ventilation following open heart surgeries. One hundred P a O 2 -F i O 2 data pairs were obtained from 25 non-smoking patients mechanically ventilated following open heart surgeries. One data pair was collected at each of F i O 2 of 40, 60, 80, and 100% while maintaining same mechanical ventilation support settings. Similarly, another 100 hundred P a O 2 -F i O 2 data pairs were obtained from 25 smoking patients mechanically ventilated following open heart surgeries. The utility of the new mathematical expression in accurately describing the P a O 2 -F i O 2 relationship in these patients was assessed by the regression and Bland-Altman analyses. Significant correlations were seen between the true and estimated F i O 2 values in non-smoking (r 2  = 0.9424; p < 0.05) and smoking (r 2  = 0.9466; p < 0.05) patients. Tight biases between the true and estimated F i O 2 values for non-smoking (3.1%) and smoking (4.1%) patients were observed. Also, significant correlations were seen between the true and estimated P a O 2 /F i O 2 ratios in non-smoking (r 2  = 0.9530; p < 0.05) and smoking (r 2  = 0.9675; p < 0.05) patients. Tight biases between the true and estimated P a O 2 /F i O 2 ratios for non-smoking (-18 mmHg) and smoking (-16 mmHg) patients were also observed. The new mathematical expression for the description of the P a O 2 -F i O 2 relationship is valid and accurate in non-smoking and smoking patients who are receiving mechanical ventilation for post cardiac surgery.

  2. Oxygen tension regulates the miRNA profile and bioactivity of exosomes released from extravillous trophoblast cells - Liquid biopsies for monitoring complications of pregnancy.

    Directory of Open Access Journals (Sweden)

    Grace Truong

    Full Text Available Our understanding of how cells communicate has undergone a paradigm shift since the recent recognition of the role of exosomes in intercellular signaling. In this study, we investigated whether oxygen tension alters the exosome release and miRNA profile from extravillous trophoblast (EVT cells, modifying their bioactivity on endothelial cells (EC. Furthermore, we have established the exosomal miRNA profile at early gestation in women who develop pre-eclampsia (PE and spontaneous preterm birth (SPTB. HTR-8/SVneo cells were used as an EVT model. The effect of oxygen tension (i.e. 8% and 1% oxygen on exosome release was quantified using nanocrystals (Qdot® coupled to CD63 by fluorescence NTA. A real-time, live-cell imaging system (Incucyte™ was used to establish the effect of exosomes on EC. Plasma samples were obtained at early gestation (<18 weeks and classified according to pregnancy outcomes. An Illumina TrueSeq Small RNA kit was used to construct a small RNA library from exosomal RNA obtained from EVT and plasma samples. The number of exosomes was significantly higher in EVT cultured under 1% compared to 8% oxygen. In total, 741 miRNA were identified in exosomes from EVT. Bioinformatic analysis revealed that these miRNA were associated with cell migration and cytokine production. Interestingly, exosomes isolated from EVT cultured at 8% oxygen increased EC migration, whilst exosomes cultured at 1% oxygen decreased EC migration. These changes were inversely proportional to TNF-α released from EC. Finally, we have identified a set of unique miRNAs in exosomes from EVT cultured at 1% oxygen and exosomes isolated from the circulation of mothers at early gestation, who later developed PE and SPTB. We suggest that aberrant exosomal signalling by placental cells is a common aetiological factor in pregnancy complications characterised by incomplete SpA remodeling and is therefore a clinically relevant biomarker of pregnancy complications.

  3. Oxygen tension and riboflavin gradients cooperatively regulate the migration of Shewanella oneidensis MR-1 revealed by a hydrogel-based microfluidic device

    Directory of Open Access Journals (Sweden)

    Beum Jun Kim

    2016-09-01

    Full Text Available Shewanella oneidensis (S. oneidensis is a model bacterial strain for studies of bioelectrochemical systems (BESs. It has two extracellular electron transfer pathways: 1 shuttling electrons via an excreted mediator riboflavin; and 2 direct contact between the c-type cytochromes at the cell membrane and the electrode. Despite the extensive use of S. oneidensis in bioelectrochemical systems such as microbial fuel cells and biosensors, many basic microbiology questions about S. oneidensis in the context of BES remain unanswered. Here, we present studies of motility and chemotaxis of S. oneidensis under well controlled concentration gradients of two electron acceptors, oxygen and oxidized form of riboflavin (flavin+ using a newly developed microfluidic platform. Experimental results demonstrate that either oxygen or flavin+ is a chemoattractant to S. oneidensis. The chemotactic tendency of S. oneidensis in a flavin+ concentration gradient is significantly enhanced in an anaerobic in contrast to an aerobic condition. Furthermore, either a low oxygen tension or a high flavin+ concentration considerably enhances the speed of S. oneidensis. This work presents a robust microfluidic platform for generating oxygen and/or flavin+ gradients in an aqueous environment, and demonstrates that two important electron acceptors, oxygen and oxidized riboflavin, cooperatively regulate S. oneidensis migration patterns. The microfluidic tools presented as well as the knowledge gained in this work can be used to guide the future design of BESs for efficient electron production.

  4. A novel system for transcutaneous application of carbon dioxide causing an "artificial Bohr effect" in the human body.

    Directory of Open Access Journals (Sweden)

    Yoshitada Sakai

    Full Text Available BACKGROUND: Carbon dioxide (CO(2 therapy refers to the transcutaneous administration of CO(2 for therapeutic purposes. This effect has been explained by an increase in the pressure of O(2 in tissues known as the Bohr effect. However, there have been no reports investigating the oxygen dissociation of haemoglobin (Hb during transcutaneous application of CO(2in vivo. In this study, we investigate whether the Bohr effect is caused by transcutaneous application of CO2 in human living body. METHODS: We used a novel system for transcutaneous application of CO(2 using pure CO(2 gas, hydrogel, and a plastic adaptor. The validity of the CO(2 hydrogel was confirmed in vitro using a measuring device for transcutaneous CO(2 absorption using rat skin. Next, we measured the pH change in the human triceps surae muscle during transcutaneous application of CO(2 using phosphorus-31 magnetic resonance spectroscopy ((31P-MRS in vivo. In addition, oxy- and deoxy-Hb concentrations were measured with near-infrared spectroscopy in the human arm with occulted blood flow to investigate O2 dissociation from Hb caused by transcutaneous application of CO(2. RESULTS: The rat skin experiment showed that CO(2 hydrogel enhanced CO(2 gas permeation through the rat skin. The intracellular pH of the triceps surae muscle decreased significantly 10 min. after transcutaneous application of CO(2. The NIRS data show the oxy-Hb concentration decreased significantly 4 min. after CO(2 application, and deoxy-Hb concentration increased significantly 2 min. after CO(2 application in the CO(2-applied group compared to the control group. Oxy-Hb concentration significantly decreased while deoxy-Hb concentration significantly increased after transcutaneous CO(2 application. CONCLUSIONS: Our novel transcutaneous CO(2 application facilitated an O(2 dissociation from Hb in the human body, thus providing evidence of the Bohr effect in vivo.

  5. Modification of the radiation response of pig skin by manipulation of tissue oxygen tension using anesthetics and administration of BW12C

    International Nuclear Information System (INIS)

    van den Aardweg, G.J.; Hopewell, J.W.; Barnes, D.W.; Sansom, J.M.; Nethersell, A.B.

    1989-01-01

    The importance of tissue oxygen tension on radiosensitivity was studied by examining modifications in the incidence of moist desquamation in pig skin after irradiation with strontium-90 plaques. The effects were analyzed using quantal dose-response data and comparisons were made using ED50 values for moist desquamation. Under standard anesthetic conditions of 2% halothane, approximately 70% oxygen, and approximately 30% nitrous oxide, the ED50 value (+/- SE) for moist desquamation was 27.32 +/- 0.52 Gy with no significant variation in radiosensitivity between dorsal, lateral, and ventral skin sites on the flank. Irradiation with 2% halothane and air increased the ED50 to 31.25 +/- 0.94 Gy, primarily due to an increased radioresistance of the dorsal sites. When combined with BW12C, a drug which binds oxygen selectively to hemoglobin and hence reduced the oxygen availability to tissues, a further increase in the ED50 values was observed. This was approximately 39 Gy with BW12C concentrations of 30 mg/kg and 50 mg/kg b.w. of BW12C, indicating a dose modification factor (DMF) of approximately 1.26. However, when animals were breathing the standard gas mixture, this DMF was reduced to 1.15 for 30 mg/kg of BW12C, indicating that a higher level of oxygen partly counteracted the effects of the drug in these studies with BW12C. The greatest variability in radiosensitivity was seen in the dorsal fields. This suggested complex physiological adaptation, a phenomenon that might also explain the absence of any modification of the radiation response when 100 mg/kg of BW12C was used

  6. The effect of oxygen tension in the sediment on the behaviour of waste radionuclides at the NEA Atlantic dumpsite

    International Nuclear Information System (INIS)

    Rutgers van der Loeff, M.M.; Waijers, D.A.

    1985-01-01

    Predictions of the transport and fate of waste radionuclides at the NEA Atlantic dumpsite require a knowledge of the behaviour of these nuclides within the sediment. Since redox conditions are known to influence the mobility of many elements in deep-sea sediments, we have investigated the speciation of some trace elements in relation to the dissolved oxygen concentration in sediments from the dumpsite. Dissolved oxygen in these sediments penetrates mostly between 50 and 100 cm, although at topographic highs and on hillsides oxygen penetrates more than 2 m into the sediment because of the special hydrodynamic and sedimentological conditions there. Remobilization at lowered redox potentials below the depth where oxygen reaches zero causes an upward diffusive transport of Mn and the manganese-associated trace metals Co and Ni. Whether this diagenetic mobilization influences other elements such as rare earth elements and actinides as well, remains to be investigated. Under normal sedimentological condition this mobilization can not be expected to return radioactivity to the water column through an oxidized sediment layer of 50 cm. However, burial of radioactivity to depths beyond the reach of deep burrowing organisms can be significantly delayed. Kd values (solid/dissolved partition coefficients) of redox sensitive elements vary over orders of magnitude and are inappropriate to model the behaviour of these elements in sediments with redox gradients

  7. Changes in the metabolic footprint of placental explant-conditioned medium cultured in different oxygen tensions from placentas of small for gestational age and normal pregnancies.

    LENUS (Irish Health Repository)

    Horgan, R P

    2012-01-31

    Being born small for gestational age (SGA) confers significantly increased risks of perinatal morbidity and mortality. Accumulating evidence suggests that an SGA fetus results from a poorly perfused and abnormally developed placenta. Some of the placental features seen in SGA, such as abnormal cell turnover and impaired nutrient transport, can be reproduced by culture of placental explants in hypoxic conditions. Metabolic footprinting offers a hypothesis-generating strategy to investigate factors absorbed by and released from this tissue in vitro. Previously, metabolic footprinting of the conditioned culture media has identified differences in placental explants cultured under normoxic and hypoxic conditions and between normal pregnancies and those complicated by pre-eclampsia. In this study we aimed to examine the differences in the metabolic footprint of placental villous explants cultured at different oxygen (O(2)) tensions between women who deliver an SGA baby (n = 9) and those from normal controls (n = 8). Placental villous explants from cases and controls were cultured for 96 h in 1% (hypoxic), 6% (normoxic) and 20% (hyperoxic) O(2). Metabolic footprints were analysed by Ultra Performance Liquid Chromatography coupled to an electrospray hybrid LTQ-Orbitrap Mass Spectrometry (UPLC-MS). 574 metabolite features showed significant difference between SGA and normal at one or more of the oxygen tensions. SGA explant media cultured under hypoxic conditions was observed, on a univariate level, to exhibit the same metabolic signature as controls cultured under normoxic conditions in 49% of the metabolites of interest, suggesting that SGA tissue is acclimatised to hypoxic conditions in vivo. No such behaviour was observed under hyperoxic culture conditions. Glycerophospholipid and tryptophan metabolism were highlighted as areas of particular interest.

  8. [Reduced muscular oxygen tension and nerve impulse transmission from antishock hose. Reduction of oxygen tension in the tibial muscle and impulse transmission in the peroneal nerve from pneumatic -1 pressure from antishock hose].

    Science.gov (United States)

    Willy, C; Völker, H U; Weber, F; Albert, U; Sterk, J; Helm, M; Gerngross, H; Thomas, A

    1998-07-01

    The aim of the study was to assess, whether the pneumatic pressure of an antishock-trouser (AST) of 20-40 mm Hg induces a decreased oxygenation of the anterior tibial muscle and attenuates muscular response potential (MRP) of n. peronaeus profundus? Among 22 normotensive, healthy volunteers the AST were tested by applying pressure values between 0 and 100 mm Hg and measuring the intracompartmental pressure, the muscular oxygen pressure as well as the MRP by electroneurographic means within a period of 6 hours. The median initial intracompartmental pressure value of the m. tibialis anterior was 12.0 mm Hg (Q25%/Q75%: 8.9/17.3), the muscular oxygen pressure 14.8 mm Hg (Q25%/Q75%: 11.5/22.0). Transmission of the pneumatic AST-leg segment pressure to the muscle: 97.7% (Q25%/Q75%: 89.2/99.8). Already in the low AST pressure field (20-40 mm Hg) a severe hypoxia occurred in one case. A reduction of MRP was noticed at an AST pressure rate of 10 mm Hg. In 5 of 6 cases AST pressure values of 60 mm Hg led to pathological pO2-values within 5-20 minutes. Almost without exception AST-pressure rates < 60 mm Hg resulted in an anoxia of the muscle and loss of the MRP. We should demand that the AST are only applied with models where the pressure generated within the single segments can be controlled by pressure gauge. The application of the AST seems to be justified for polytraumatised in severe haemorrhagic shock where the risk of a local tissue ischemia with systemical consequences must deliberately be accepted.

  9. Effects of Low and High Oxygen Tensions and Related Respiratory Conditions on Visual Performance: A Literature Review

    Science.gov (United States)

    1988-07-01

    and of the same subject after a diet that made him deficient in Vitamin A. They used only one healthy well-trained observer. Measurementv of...background intensity. The authors do not discuss hypoxia changes in some other visual process, but this improvement above 15,000 feet may reflect hypo ...these studies, Gellhorn and Spiesman (1935) induced caloric nystagmus while subjects breathed mixtures high in CO2 and low in oxygen, and also after

  10. Transcutaneous Raman Spectroscopy of Bone

    Science.gov (United States)

    Maher, Jason R.

    Clinical diagnoses of bone health and fracture risk typically rely upon measurements of bone density or structure, but the strength of a bone is also dependent upon its chemical composition. One technology that has been used extensively in ex vivo, exposed-bone studies to measure the chemical composition of bone is Raman spectroscopy. This spectroscopic technique provides chemical information about a sample by probing its molecular vibrations. In the case of bone tissue, Raman spectra provide chemical information about both the inorganic mineral and organic matrix components, which each contribute to bone strength. To explore the relationship between bone strength and chemical composition, our laboratory has contributed to ex vivo, exposed-bone animal studies of rheumatoid arthritis, glucocorticoid-induced osteoporosis, and prolonged lead exposure. All of these studies suggest that Raman-based predictions of biomechanical strength may be more accurate than those produced by the clinically-used parameter of bone mineral density. The utility of Raman spectroscopy in ex vivo, exposed-bone studies has inspired attempts to perform bone spectroscopy transcutaneously. Although the results are promising, further advancements are necessary to make non-invasive, in vivo measurements of bone that are of sufficient quality to generate accurate predictions of fracture risk. In order to separate the signals from bone and soft tissue that contribute to a transcutaneous measurement, we developed an overconstrained extraction algorithm that is based upon fitting with spectral libraries derived from separately-acquired measurements of the underlying tissue components. This approach allows for accurate spectral unmixing despite the fact that similar chemical components (e.g., type I collagen) are present in both soft tissue and bone and was applied to experimental data in order to transcutaneously detect, to our knowledge for the first time, age- and disease-related spectral

  11. Cellular and molecular repair of X-ray-induced damage: dependence on oxygen tension and nutritional status

    International Nuclear Information System (INIS)

    Spiro, I.J.; Kennedy, K.A.; Stickler, R.; Ling, C.C.

    1985-01-01

    Cellular and molecular repair was studied at 23 0 C using split-dose recovery and alkaline elution techniques, respectively, as a function of cellular oxygen and nutrient conditions. Hypoxic cells in full medium showed a partial reduction in the level of sublethal damage (SLD) repair relative to aerated cells; the respective repair kinetics were similar with a common repair half-time of 30 min. Similarly, hypoxic cells showed a slight reduction in strand break rejoining capacity compared to aerated cells. Under nutrient deprivation, anoxic cells displayed no SLD repair or strand break repair, while aerated cells exhibited the same level of SLD and strand break repair as for well-fed cells. In addition, nutrient deprived cells at low O 2 levels displayed normal SLD and strand break repair capability. These results indicate that both nutrient and O 2 deprivation are necessary for complete inhibition of cellular and molecular repair, and low levels of O 2 can effectively reverse this inhibition

  12. Tension Headache

    Science.gov (United States)

    ... tight band around your head. A tension headache (tension-type headache) is the most common type of headache, and ... Headache after a head injury, especially if the headache gets worse ... tension or stress. But research suggests muscle contraction isn't the ...

  13. Effects of in vitro low oxygen tension preconditioning of adipose stromal cells on their in vivo chondrogenic potential: application in cartilage tissue repair.

    Directory of Open Access Journals (Sweden)

    Sophie Portron

    Full Text Available PURPOSE: Multipotent stromal cell (MSC-based regenerative strategy has shown promise for the repair of cartilage, an avascular tissue in which cells experience hypoxia. Hypoxia is known to promote the early chondrogenic differentiation of MSC. The aim of our study was therefore to determine whether low oxygen tension could be used to enhance the regenerative potential of MSC for cartilage repair. METHODS: MSC from rabbit or human adipose stromal cells (ASC were preconditioned in vitro in control or chondrogenic (ITS and TGF-β medium and in 21 or 5% O2. Chondrogenic commitment was monitored by measuring COL2A1 and ACAN expression (real-time PCR. Preconditioned rabbit and human ASC were then incorporated into an Si-HPMC hydrogel and injected (i into rabbit articular cartilage defects for 18 weeks or (ii subcutaneously into nude mice for five weeks. The newly formed tissue was qualitatively and quantitatively evaluated by cartilage-specific immunohistological staining and scoring. The phenotype of ASC cultured in a monolayer or within Si-HPMC in control or chondrogenic medium and in 21 or 5% O2 was finally evaluated using real-time PCR. RESULTS/CONCLUSIONS: 5% O2 increased the in vitro expression of chondrogenic markers in ASC cultured in induction medium. Cells implanted within Si-HPMC hydrogel and preconditioned in chondrogenic medium formed a cartilaginous tissue, regardless of the level of oxygen. In addition, the 3D in vitro culture of ASC within Si-HPMC hydrogel was found to reinforce the pro-chondrogenic effects of the induction medium and 5% O2. These data together indicate that although 5% O2 enhances the in vitro chondrogenic differentiation of ASC, it does not enhance their in vivo chondrogenesis. These results also highlight the in vivo chondrogenic potential of ASC and their potential value in cartilage repair.

  14. Inverse Regulation of Early and Late Chondrogenic Differentiation by Oxygen Tension Provides Cues for Stem Cell-Based Cartilage Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Sophie Portron

    2015-01-01

    Full Text Available Background/Aims: Multipotent stem/stromal cells (MSC are considered promising for cartilage tissue engineering. However, chondrogenic differentiation of MSC can ultimately lead to the formation of hypertrophic chondrocytes responsible for the calcification of cartilage. To prevent the production of this calcified matrix at the articular site, the late hypertrophic differentiation of MSCs must be carefully controlled. Given that articular cartilage is avascular, we hypothesized that in addition to its stimulatory role in the early differentiation of chondrogenic cells, hypoxia may prevent their late hypertrophic conversion. Methods: Early and late chondrogenic differentiation were evaluated using human adipose MSC and murine ATDC5 cells cultured under either normoxic (21%O2 or hypoxic (5%O2 conditions. To investigate the effect of hypoxia on late chondrogenic differentiation, the transcriptional activity of hypoxia-inducible factor-1alpha (HIF-1α and HIF-2α were evaluated using the NoShift DNA-binding assay and through modulation of their activity (chemical inhibitor, RNA interference. Results: Our data demonstrate that low oxygen tension not only stimulates the early chondrogenic commitment of two complementary models of chondrogenic cells, but also inhibits their hypertrophic differentiation. Conclusion: These results suggest that hypoxia can be used as an instrumental tool to prevent the formation of a calcified matrix in MSC-based cartilage tissue engineering.

  15. End-Tidal CO2 Tension Is Predictive of Effective Nocturnal Oxygen Therapy in Patients with Chronic Heart Failure and Central Sleep Apnea.

    Science.gov (United States)

    Sugimura, Koichiro; Shinozaki, Tsuyoshi; Fukui, Shigefumi; Ogawa, Hiromasa; Shimokawa, Hiroaki

    2016-05-01

    Central sleep apnea (CSA) is characterized by recurring cycles of crescendo-decrescendo ventilation during sleep, and enhances sympathetic nerve activity. Thus CSA has a prognostic impact in patients with chronic heart failure (CHF). Although nocturnal oxygen (O2) therapy decreases frequency of CSA and improves functional exercise capacity, it is also known that some non-responders to the therapy exist. We thus aimed to identify predictors of responders to nocturnal O2 therapy in CHF patients with CSA. In 12 CHF patients with CSA hospitalized at our department, sleep study was performed at 2 consecutive nights. Patients nasally inhaled O2 at either the first or second night in a randomized manner. To predict the percentage reduction in apnea-hypopnea index (%ΔAHI) in response to the nocturnal O2 therapy, we performed multiple regression analysis with a stepwise method with variables including age, brain-natriuretic peptide, circulation time, baseline AHI, hypercapnic ventilatory response and end-tidal carbon dioxide tension (PETCO2). Nocturnal O2 therapy significantly decreased AHI (from 32 ± 13 /h to 12 ± 10 /h, P 50% reduction of AHI), with 88.9% of sensitivity and 66.7% of specificity. In conclusion, PETCO2 is useful to predict the efficacy of O2 therapy in CHF patients with CSA, providing important information to the current nocturnal O2 therapy.

  16. Skin perfusion pressure measured by isotope washout in legs with arterial occlusive disease. Evaluation of different tracers, comparison to segmental systolic pressure, angiography and transcutaneous oxygen tension and variations during changes in systemic blood pressure

    DEFF Research Database (Denmark)

    Holstein, P; Trap-Jensen, J; Bagger, H

    1983-01-01

    Hg (range 18-98) (P less than 0.02). The average washout constant for the three different tracers were approximately equal and correlated statistically significant with the SPP; (2) In 59 legs with AOD, segmental SPP was compared to segmental systolic blood pressures on the thigh, calf, ankle and first...... digit (strain gauge technique). The two different methods correlated statistically significant at all four levels, but the systolic blood pressures were higher than the SPP in particular in diabetic legs; (3) Angiograms in 35 legs with AOD showed that the SPP on the ankle was only consistently decreased...

  17. 21 CFR 870.5550 - External transcutaneous cardiac pacemaker (noninvasive).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External transcutaneous cardiac pacemaker... § 870.5550 External transcutaneous cardiac pacemaker (noninvasive). (a) Identification. An external transcutaneous cardiac pacemaker (noninvasive) is a device used to supply a periodic electrical pulse intended to...

  18. Transcriptional and metabolic response of recombinant Escherichia coli to spatial dissolved oxygen tension gradients simulated in a scale-down system.

    Science.gov (United States)

    Lara, Alvaro R; Leal, Lidia; Flores, Noemí; Gosset, Guillermo; Bolívar, Francisco; Ramírez, Octavio T

    2006-02-05

    Escherichia coli, expressing recombinant green fluorescent protein (GFP), was subjected to dissolved oxygen tension (DOT) oscillations in a two-compartment system for simulating gradients that can occur in large-scale bioreactors. Cells were continuously circulated between the anaerobic (0% DOT) and aerobic (10% DOT) vessels of the scale-down system to mimic an overall circulation time of 50 s, and a mean residence time in the anaerobic and aerobic compartments of 33 and 17 s, respectively. Transcription levels of mixed acid fermentation genes (ldhA, poxB, frdD, ackA, adhE, pflD, and fdhF), measured by quantitative RT-PCR, increased between 1.5- to over 6-fold under oscillatory DOT compared to aerobic cultures (constant 10% DOT). In addition, the transcription level of fumB increased whereas it decreased for sucA and sucB, suggesting that the tricarboxylic acid cycle was functioning as two open branches. Gene transcription levels revealed that cytrochrome bd, which has higher affinity to oxygen but lower energy efficiency, was preferred over cytochrome bO3 in oscillatory DOT cultures. Post-transcriptional processing limited heterologous protein production in the scale-down system, as inferred from similar gfp transcription but 19% lower GFP concentration compared to aerobic cultures. Simulated DOT gradients also affected the transcription of genes of the glyoxylate shunt (aceA), of global regulators of aerobic and anaerobic metabolism (fnr, arcA, and arcB), and other relevant genes (luxS, sodA, fumA, and sdhB). Transcriptional changes explained the observed alterations in overall stoichiometric and kinetic parameters, and production of ethanol and organic acids. Differences in transcription levels between aerobic and anaerobic compartments were also observed, indicating that E. coli can respond very fast to intermittent DOT conditions. The transcriptional responses of E. coli to DOT gradients reported here are useful for establishing rational scale-up criteria and

  19. Repetitive reduction of uterine blood flow and its influence on fetal transcutaneous PO2 and cardiovascular variables.

    Science.gov (United States)

    Jensen, A; Künzel, W; Kastendieck, E

    1985-04-01

    The influence of repeated asphyxia on fetal transcutaneous PO2, relative local skin perfusion, heart rate, blood gases and pH was investigated in 15 experiments on 8 acutely instrumented sheep fetuses in utero between 125 and 145 days gestation (term is 147 days). Uterine blood flow was intermittently arrested (11 times within 33 min) by intra-vascular maternal aortic occlusion, exposing the fetuses to repeated episodes of asphyxia of 30 (n = 3), 60 (n = 9) and 90 (n = 3) s duration. The fetal transcutaneous PO2 fell as the duration of asphyxia (2 alpha less than 0.01), heart rate deceleration area (2 alpha less than 0.01) and acidaemia (2 alpha less than 0.01) increased. With decreasing skin perfusion, which was dependent on the duration of asphyxia (2 alpha less than 0.001) and acidaemia (2 alpha less than 0.001), a discrepancy developed between transcutaneous and arterial PO2. The increase (delta) in transcutaneous-arterial PO2 difference was related linearly to the duration of asphyxia (2 alpha less than 0.01), the mean haemoglobin oxygen saturation (2 alpha less than 0.001), acidaemia (2 alpha less than 0.001) and relative local skin flow (2 alpha less than 0.05). It was highest after severe episodes of asphyxia (90 s), when O2 saturation, skin blood flow and arterial blood pH values were low. Fetal heart rate deceleration area was only correlated with the cutaneous-arterial PO2 difference when the mean fetal haemoglobin oxygen saturation was below 35%. Thus, a discrimination of heart rate decelerations that are significant for the fetus seems to be possible, when associated with low transcutaneous PO2 values. We conclude that in the sheep fetus transcutaneous PO2 measurements during repeated asphyxial episodes yield information on fetal oxygenation and on the skin vasomotor response.

  20. A hybrid multibreath wash-in wash-out lung function quantification scheme in human subjects using hyperpolarized 3 He MRI for simultaneous assessment of specific ventilation, alveolar oxygen tension, oxygen uptake, and air trapping.

    Science.gov (United States)

    Hamedani, Hooman; Kadlecek, Stephen; Xin, Yi; Siddiqui, Sarmad; Gatens, Heather; Naji, Joseph; Ishii, Masaru; Cereda, Maurizio; Rossman, Milton; Rizi, Rahim

    2017-08-01

    To present a method for simultaneous acquisition of alveolar oxygen tension (P A O 2 ), specific ventilation (SV), and apparent diffusion coefficient (ADC) of hyperpolarized (HP) gas in the human lung, allowing reinterpretation of the P A O 2 and SV maps to produce a map of oxygen uptake (R). An imaging scheme was designed with a series of identical normoxic HP gas wash-in breaths to measure ADC, SV, P A O 2 , and R in less than 2 min. Signal dynamics were fit to an iterative recursive model that regionally solved for these parameters. This measurement was successfully performed in 12 subjects classified in three healthy, smoker, and chronic obstructive pulmonary disease (COPD) cohorts. The overall whole lung ADC, SV, P A O 2 , and R in healthy, smoker, and COPD subjects was 0.20 ± 0.03 cm 2 /s, 0.39 ± 0.06,113 ± 2 Torr, and 1.55 ± 0.35 Torr/s, respectively, in healthy subjects; 0.21 ± 0.03 cm 2 /s, 0.33 ± 0.06, 115.9 ± 4 Torr, and 0.97 ± 0.2 Torr/s, respectively, in smokers; and 0.25 ± 0.06 cm 2 /s, 0.23 ± 0.08, 114.8 ± 6.0Torr, and 0.94 ± 0.12 Torr/s, respectively, in subjects with COPD. Hetrogeneity of SV, P A O 2 , and R were indicators of both smoking-related changes and disease, and the severity of the disease correlated with the degree of this heterogeneity. Subjects with symptoms showed reduced oxygen uptake and specific ventilation. High-resolution, nearly coregistered and quantitative measures of lung function and structure were obtained with less than 1 L of HP gas. This hybrid multibreath technique produced measures of lung function that revealed clear differences among the cohorts and subjects and were confirmed by correlations with global lung measurements. Magn Reson Med 78:611-624, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  1. Transcutaneous immunization using microneedles and cubosomes

    DEFF Research Database (Denmark)

    Rattanapak, Teerawan; Birchall, James; Young, Katherine

    2013-01-01

    Transcutaneous (TCI) immunization is a novel vaccination approach that provides many advantages over traditional parenteral vaccination. However, a major barrier to TCI is mediating penetration of vaccine antigens through the stratum corneum (SC) to the deeper tissue layers. Many approaches have...

  2. Tension headache.

    Science.gov (United States)

    Ziegler, D K

    1978-05-01

    Headache is an extremely common symptom, and many headaches undoubtedly have a relationship to stressful situations. The clear definition, however, of a "tension headache" complex and its differentiation from migraine in some patients is difficult. The problems are in the identification of a specific headache pattern induced by stress or "tension" and the relationship of the symptom to involuntary contraction of neck and scalp muscles. Treatment consists of analgesics and occasionally mild tranquilizers. Psychotherapy consists of reassurance and often other supportive measures, including modification of life styles. Various feedback techniques have been reported of value, but their superiority to suggestion and hypnosis is still problematic.

  3. L-lysine escinat, thiotriazolin, gordox and mydocalm influence on oxygen tension in the intestinal wall and acid-base balance and limited proteolysis in intestinal venous blood in terms of intraabdominal hypertension modeling

    Directory of Open Access Journals (Sweden)

    Sapegin V.I.

    2014-11-01

    Full Text Available In acute experiments on rabbits there were studied changes in oxygen tension in the intestinal wall tissues, acid-base balance and limited proteolysis and its inhibitors in intestinal venous blood, protective action of L-lysine escinat (0,15 mg/kg / single dose, thiotriazolin (25 mg/kg / single dose, aprotinin (gordox (10,000 units/kg / single dose in sequential modeling of standard levels increasing of intra-abdominal hypertension (IAH — 50, 100, 150, 200, 250, 300, 350 m H2O, and also of tolperison (mydocalm (5 mg/kg / single dose on modeling of stable 3-hour IAH 200 m H2O. The IAH modeling was performed by means of stand of our construction. Under the influence of IAH the compensated metabolic acidosis in intestinal venous blood with a compensative hyperpnoe develops, decline of oxygen tension in tissues and activating of a limited proteolysis as well as decline of its inhibitors activity in intestinal venous blood occur. By the degree of metabolic acidosis prevention investigational preparations were distributed as follows gordox > thiotriazolin = L-lysine escinat = mydocalm, and by prevention of decline of oxygen tension in tissues — thiotriazolin > L-lysine escinat > mydocalm > gordox, it is is connected with different rate of methabolic products excretion into the blood, due to the influence on blood circulation and transcapilary exchange. By the degree of prevention of proteolytic activity and inhibitory potential changes, investigational preparations were distributed as follows: gordox > mydocalm > thiotriazolin > L-lysine escinat, this is connected with inhibition of proteolysis in gordox, and in other ones – with reduction of ischemic damage of tissues. Owing to different mechanism of action thiotriazolin, L-lysine escinat and mydocalm may be simultaneously recommended for a conservative treatment of patients with intraabdominal hypertension syndrome.

  4. Transcutaneous electrical neurostimulation in functional pain.

    Science.gov (United States)

    Richardson, R R; Arbit, J; Siqueira, E B; Zagar, R

    1981-01-01

    Transcutaneous electrical neurostimulation (TENS) has recently emerged as a distinct therapeutic modality in the alleviation of acute and chronic pain. We applied this modality to 15 nonsurgical low-back pain patients having diagnoses of functional pain, with 40% initially having significant pain relief (50% of greater). However, this pain-alleviating effect of TENS did not last longer than two months. After initiation of neurostimulation, increased pain and/or bizarre and inappropriate sensations and behavior frequently developed. We also applied this modality in the diagnostic evaluation and treatment of 24 patients having diagnoses of postsurgical chronic intractable low-back pain of psychosomatic origin and achieved similar results. In both groups, we utilized a simplified poststimulation "normal-saline-sterile-water intramuscular injection test" to confirm the findings from transcutaneous electrical neurostimulation and to verify the functional basis of the present low-back pain.

  5. Arterial oxygen tension and pulmonary ventilation in horses placed in the Anderson Sling suspension system after a period of lateral recumbency and anaesthetised with constant rate infusions of romifidine and ketamine.

    Science.gov (United States)

    François, I; Lalèyê, F-X; Micat, M; Benredouane, K; Portier, K

    2014-09-01

    Some controversy exists over whether or not horses' recovery and cardiopulmonary function are affected by suspension in slings. To measure arterial oxygen tension and pulmonary ventilation in anaesthetised horses placed in a standing position in an Anderson Sling (AS) after a period of right lateral recumbency (RLR). Randomised crossover experimental study. Six Standardbred horses were anaesthetised twice. Catheters were inserted into the right jugular vein and the left carotid artery. After premedication with romifidine, anaesthesia was induced with diazepam and ketamine. Following 50 min in RLR, horses were maintained in either RLR or AS for an additional 60 min through to recovery. Anaesthesia was maintained i.v. with a constant rate infusion of romifidine and ketamine. Heart rate, respiratory rate, mean arterial pressure, expiratory tidal volume, minute volumes and end tidal CO2 were monitored continuously. Venous and arterial bloods were sampled for lactate concentration, creatine kinase activity and blood gas analysis before premedication, after induction, every 20 min for 100 min, as soon as the horse was standing (TR), and 24 h later. The data were averaged within 2 anaesthetic periods: P1, 0-20 min; and P2, 40-100 min. During P2, horses in the RLR group had lower arterial oxygen tension (P = 0.001), higher alveolar-arterial oxygen tension gradient (P = 0.005), higher respiratory rate (P = 0.04) and higher minute volumes (P = 0.04) than horses in the AS group. Arterial CO2 tension and mean arterial pressure increased in the AS group during P2 (P = 0.01 and 0.02 respectively). The recoveries were judged better in the AS group than in the RLR group (P = 0.01). During TR, lactate were higher in the RLR group than in the AS group (P = 0.007). Creatine kinase activities were higher in the AS group at 24 h vs. TR (P = 0.02). Anderson Sling suspension after a period of recumbency improves cardiopulmonary function and recovery quality in horses and

  6. Transcutaneous sacral neurostimulation for irritative voiding dysfunction.

    Science.gov (United States)

    Walsh, I K; Johnston, R S; Keane, P F

    1999-01-01

    Patients with irritative voiding dysfunction are often unresponsive to standard clinical treatment. We evaluated the response of such individuals to transcutaneous electrical stimulation of the third sacral nerve. 32 patients with refractory irritative voiding dysfunction (31 female and 1 male; mean age 47 years) were recruited to the study. Ambulatory transcutaneous electrical neurostimulation was applied bilaterally to the third sacral dermatomes for 1 week. Symptoms of frequency, nocturia, urgency, and bladder pain were scored by each patient throughout and up to 6 months following treatment. The mean daytime frequency was reduced from 11.3 to 7.96 (p = 0.01). Nocturia episodes were reduced from a mean of 2.6 to 1.8 (p = 0.01). Urgency and bladder pain mean symptom scores were reduced from 5.97 to 4.89 and from 1.48 to 0.64, respectively. After stopping therapy, symptoms returned to pretreatment levels within 2 weeks in 40% of the patients and within 6 months in 100%. Three patients who continued with neurostimulation remained satisfied with this treatment modality at 6 months. Transcutaneous third sacral nerve stimulation may be an effective and noninvasive ambulatory technique for the treatment of patients with refractory irritative voiding dysfunction. Following an initial response, patients may successfully apply this treatment themselves to ensure long-term relief.

  7. Transcutaneous oximetry measurements of the leg: comparing different measuring equipment and establishing values in healthy young adults.

    Science.gov (United States)

    Trinks, Tobias P; Blake, Denise F; Young, Derelle A; Thistlethwaite, Ken; Vangaveti, Venkat N

    2017-06-01

    Transcutaneous oximetry measurement (TCOM) is a non-invasive method of determining oxygen tension at the skin level using heated electrodes. To compare TCOM values generated by different machines and to establish lower limb TCOM values in a cohort of healthy individuals younger than 40 years of age. Sixteen healthy, non-smoking volunteers aged 18 to 39 years were recruited. TCOM was obtained at six locations on the lower leg and foot using three different Radiometer machines. Measurements were taken with subjects lying supine, breathing air. Except for one sensor site, there were no statistical differences in measurements obtained by the different TCOM machines. There was no statistical difference in measurements comparing left and right legs. Room air TCOM values for the different lower leg sites were (mean (SD) in mmHg): lateral leg 61.5 (9.2); lateral ankle 61.1 (9.7); medial ankle 59.1 (10.8); foot, first and second toe 63.4 (10.6); foot, fifth toe 59.9 (13.2) and plantar foot 74.1 (8.8). The overall mean TCOM value for the lower limb was 61 (10.8; 95% confidence intervals 60.05-62.0) mmHg. Lower-leg TCOM measurements using different Radiometer TCOM machines were comparable. Hypoxia has been defined as lower-leg TCOM values of less than 40 mmHg in non-diabetic patients and this is supported by our measurements. The majority (96.9%) of the lower leg TCOM values in healthy young adults are above the hypoxic threshold.

  8. Simultaneous estimation of transcutaneous bilirubin, hemoglobin, and melanin based on diffuse reflectance spectroscopy

    Science.gov (United States)

    Nishidate, Izumi; Abdul, Wares MD.; Ohtsu, Mizuki; Nakano, Kazuya; Haneishi, Hideaki

    2018-02-01

    We propose a method to estimate transcutaneous bilirubin, hemoglobin, and melanin based on the diffuse reflectance spectroscopy. In the proposed method, the Monte Carlo simulation-based multiple regression analysis for an absorbance spectrum in the visible wavelength region (460-590 nm) is used to specify the concentrations of bilirubin (Cbil), oxygenated hemoglobin (Coh), deoxygenated hemoglobin (Cdh), and melanin (Cm). Using the absorbance spectrum calculated from the measured diffuse reflectance spectrum as a response variable and the extinction coefficients of bilirubin, oxygenated hemoglobin, deoxygenated hemoglobin, and melanin, as predictor variables, multiple regression analysis provides regression coefficients. Concentrations of bilirubin, oxygenated hemoglobin, deoxygenated hemoglobin, and melanin, are then determined from the regression coefficients using conversion vectors that are numerically deduced in advance by the Monte Carlo simulations for light transport in skin. Total hemoglobin concentration (Cth) and tissue oxygen saturation (StO2) are simply calculated from the oxygenated hemoglobin and deoxygenated hemoglobin. In vivo animal experiments with bile duct ligation in rats demonstrated that the estimated Cbil is increased after ligation of bile duct and reaches to around 20 mg/dl at 72 h after the onset of the ligation, which corresponds to the reference value of Cbil measured by a commercially available transcutaneous bilirubin meter. We also performed in vivo experiments with rats while varying the fraction of inspired oxygen (FiO2). Coh and Cdh decreased and increased, respectively, as FiO2 decreased. Consequently, StO2 was dramatically decreased. The results in this study indicate potential of the method for simultaneous evaluation of multiple chromophores in skin tissue.

  9. On developing a thesis for Reproductive Endocrinology and Infertility fellowship: a case study of ultra-low (2%) oxygen tension for extended culture of human embryos.

    Science.gov (United States)

    Kaser, Daniel J

    2017-03-01

    Fellows in Reproductive Endocrinology and Infertility training are expected to complete 18 months of clinical, basic, or epidemiological research. The goal of this research is not only to provide the basis for the thesis section of the oral board exam but also to spark interest in reproductive medicine research and to provide the next generation of physician-scientists with a foundational experience in research design and implementation. Incoming fellows often have varying degrees of training in research methodology and, likewise, different career goals. Ideally, selection of a thesis topic and mentor should be geared toward defining an "answerable" question and building a practical skill set for future investigation. This contribution to the JARG Young Investigator's Forum revisits the steps of the scientific method through the lens of one recently graduated fellow and his project aimed to test the hypothesis that "sequential oxygen exposure (5% from days 1 to 3, then 2% from days 3 to 5) improves blastocyst yield and quality compared to continuous exposure to 5% oxygen among human preimplantation embryos."

  10. Oxygen tension in transplanted mouse osteosarcomas during fractionated high-LET- and low-LET radiotherapy - predictive aspects for choosing beam quality?

    International Nuclear Information System (INIS)

    Auberger, T.; Thuerriegel, B.; Freude, T.; Weissfloch, L.; Kneschaurek, P.; Molls, M.; Senekowitsch-Schmidtke, R.; Wagner, F.M.

    1999-01-01

    Murine OTS64 - osteosarcomas were tranplanted in 102 balb-C mice and irradiated by 36 Gy of photons in fractions of 3 Gy five times a week (group P-36/3) or by 12 Gy of reactor fission neutrons in fractions of 2 Gy two times a week (group N-12/2). Irradiations started at a tumor volume of 500 to 600 mm 3 . A third group received no radiotherapy, but all investigations (group CG). Tumor volume and tumor oxygenation were measured once a week under therapy and during three weeks after therapy. For in vivo-evaluation of oxygen status a computerized polarographic needle electrode system (KIMOC pO 2 histograph, Eppendorf) was used. The median pO 2 and the hypoxic fraction (pO 2 values 2 decreased from 20 mm to 8 mm Hg and the hypoxic fraction increased from 7% to 31%. After fractionated photon therapy a growth delay of three weeks was observed. Six weeks after beginning of the irradiation the median tumor volume had been doubled again. After fission neutron therapy growth delay continued until the end of the follow-up period. In both of the irradiated groups a significant decrease of median pO 2 values and an increase of the hypoxic fraction were observed under radiotherapy. Hypoxia was more intensive after neutrons with a decrease of the median pO 2 from 20 mm Hg to 1 mm Hg vs. 10 mm Hg after photon therapy and with an increase of the hypoxic fraction from 7% to 78% vs. 36% respectively. Two weeks after the end of therapy the median pO 2 and the hypoxic fraction of both treated groups reached the levels prior to irradiation indicating a complete reoxygenation. (orig.)

  11. Intra-operative tissue oxygen tension is increased by local insufflation of humidified-warm CO2 during open abdominal surgery in a rat model.

    Directory of Open Access Journals (Sweden)

    Jean K Marshall

    Full Text Available Maintenance of high tissue oxygenation (PtO2 is recommended during surgery because PtO2 is highly predictive of surgical site infection and colonic anastomotic leakage. However, surgical site perfusion is often sub-optimal, creating an obstructive hurdle for traditional, systemically applied therapies to maintain or increase surgical site PtO2. This research tested the hypothesis that insufflation of humidified-warm CO2 into the abdominal cavity would increase sub-peritoneal PtO2 during open abdominal surgery.15 Wistar rats underwent laparotomy under general anesthesia. Three sets of randomized cross-over experiments were conducted in which the abdominal cavity was subjected to alternating exposure to 1 humidified-warm CO2 & ambient air; 2 humidified-warm CO2 & dry-cold CO2; and 3 dry-cold CO2 & ambient air. Sub-peritoneal PtO2 and tissue temperature were measured with a polarographic oxygen probe.Upon insufflation of humidified-warm CO2, PtO2 increased by 29.8 mmHg (SD 13.3; p<0.001, or 96.6% (SD 51.9, and tissue temperature by 3.0°C (SD 1.7 p<0.001, in comparison with exposure to ambient air. Smaller, but significant, increases in PtO2 were seen in experiments 2 and 3. Tissue temperature decreased upon exposure to dry-cold CO2 compared with ambient air (-1.4°C, SD 0.5, p = 0.001.In a rat model, insufflation of humidified-warm CO2 into the abdominal cavity during open abdominal surgery causes an immediate and potentially clinically significant increase in PtO2. The effect is an additive result of the delivery of CO2 and avoidance of evaporative cooling via the delivery of the CO2 gas humidified at body temperature.

  12. Effect of culture at low oxygen tension on the expression of heat shock proteins in a panel of melanoma cell lines.

    Directory of Open Access Journals (Sweden)

    Christopher Shipp

    Full Text Available Tumours are commonly hypoxic and this can be associated with aggressive tumour type, metastasis and resistance to therapy. Heat shock proteins (hsps are induced in response to hypoxia, provide cancer cells with protection against tumour-associated stressors and chaperone oncoproteins that drive tumour proliferation. This study examined the effect of different oxygen concentrations on the expression of hsps in melanoma cell lines.Melanoma cell lines were cultured in 2% and 20% O(2. Expression of Hsp90, Hsp70, Hsp60, Hsp40 and Hsp32 proteins were determined by flow cytometry.Growth rates and viability were reduced in the majority of cell lines by culture in 2% O(2. Hsp expression was different in 2% compared to 20% O(2 and changes in Hsp90 expression correlated with cell line generation time (P<0.005 and viability (P<0.01. Greater total hsp expression correlated with improved viability in 2% but not 20% O(2 (P<0.05. Relative expression of the different hsps was consistent across cell lines and each correlated with the others (P = 0.0001 but not with Hsp32. Hsp expression was inversely correlated with cell line adhesion to laminin as well as collagen type IV and Breslow depth of the original primary tumour tissue (P<0.05, but not with Clark level or patient survival. All five hsps were identified on the cell surface.Culture in 2% O(2 variably altered hsp expression in a panel of melanoma cell lines. Hsp expression was associated with certain cell line characteristics and clinical parameters of the originating tumour.

  13. Effects of hyperoxia on 18F-fluoro-misonidazole brain uptake and tissue oxygen tension following middle cerebral artery occlusion in rodents: Pilot studies.

    Directory of Open Access Journals (Sweden)

    Tim D Fryer

    Full Text Available Mapping brain hypoxia is a major goal for stroke diagnosis, pathophysiology and treatment monitoring. 18F-fluoro-misonidazole (FMISO positron emission tomography (PET is the gold standard hypoxia imaging method. Normobaric hyperoxia (NBO is a promising therapy in acute stroke. In this pilot study, we tested the straightforward hypothesis that NBO would markedly reduce FMISO uptake in ischemic brain in Wistar and spontaneously hypertensive rats (SHRs, two rat strains with distinct vulnerability to brain ischemia, mimicking clinical heterogeneity.Thirteen adult male rats were randomized to distal middle cerebral artery occlusion under either 30% O2 or 100% O2. FMISO was administered intravenously and PET data acquired dynamically for 3hrs, after which magnetic resonance imaging (MRI and tetrazolium chloride (TTC staining were carried out to map the ischemic lesion. Both FMISO tissue uptake at 2-3hrs and FMISO kinetic rate constants, determined based on previously published kinetic modelling, were obtained for the hypoxic area. In a separate group (n = 9, tissue oxygen partial pressure (PtO2 was measured in the ischemic tissue during both control and NBO conditions.As expected, the FMISO PET, MRI and TTC lesion volumes were much larger in SHRs than Wistar rats in both the control and NBO conditions. NBO did not appear to substantially reduce FMISO lesion size, nor affect the FMISO kinetic rate constants in either strain. Likewise, MRI and TTC lesion volumes were unaffected. The parallel study showed the expected increases in ischemic cortex PtO2 under NBO, although these were small in some SHRs with very low baseline PtO2.Despite small samples, the apparent lack of marked effects of NBO on FMISO uptake suggests that in permanent ischemia the cellular mechanisms underlying FMISO trapping in hypoxic cells may be disjointed from PtO2. Better understanding of FMISO trapping processes will be important for future applications of FMISO imaging.

  14. CONTINUOUS MONITORING OF LACTATE DURING EXERCISE IN HUMANS USING SUBCUTANEOUS AND TRANSCUTANEOUS MICRODIALYSIS

    NARCIS (Netherlands)

    DEBOER, J; PLIJTERGROENDIJK, H; VISSER, KR; MOOK, GA; KORF, J

    1994-01-01

    We have evaluated the possibility of monitoring the plasma lactate concentration in human volunteers during cycle ergometer exercise using subcutaneous and transcutaneous microdialysis. In transcutaneous microdialysis, the relative increase in dialysate lactate concentration exceeded that of plasma

  15. Assessment of the respiratory metabolism in the skin from transcutaneous measurements of pO2 and pCO2: potential for non-invasive monitoring of response to tuberculin skin testing.

    Science.gov (United States)

    Abbot, N C; Spence, V A; Swanson-Beck, J; Carnochan, F M; Gibbs, J H; Lowe, J G

    1990-03-01

    A method is described for non-invasive transcutaneous (tc) measurement of tissue respiratory gas tensions in the skin on the forearm for study of delayed hypersensitivity reactions in man. Steady state values for tcpO2 and tcpCO2 were measured, and the skin respiratory rate (oxygen consumption) and the tissue pH were estimated from the changes in tcpO2 and tcpCO2 observed after interruption of the arterial circulation by cuff occlusion for 4 minutes. The extent of within-experiment and between subject variation in the steady-state measurements was not great (coefficient of variation 10%): tcpCO2.ss (steady state) was higher in men and tcpO2.ss was higher in women, but the extent of these sex differences was also small. Reference ranges have been established for tc measurements and calculated indices of tissue respiration in the undisturbed forearm skin of normal volunteers, against which the changes induced by tuberculin testing can be assessed. Severe changes, indicative of profound hypoxia and acidosis, are seen in intense delayed hypersensitivity reactions. Similar, but less severe changes were seen at the site of skin tests on BCG-vaccinated subjects who were 'negative' by conventional criteria of measurement of dermal induration and they became greatly exaggerated after successful re-vaccination. Intradermal injection of saline did not induce hypoxia or local acidosis. These new methods are very sensitive indicators of the tissue response in the DHS reaction.

  16. Comparison of serum bilirubin estimation with transcutaneous bilirubinometry in neonates

    International Nuclear Information System (INIS)

    Waqar, T.; Ahmad, Z.; Ali, A.

    2010-01-01

    Objective: To assess usefulness of Minolta Air shield transcutaneous bilirubinometer by comparing bilirubin values obtained by transcutaneous jaundice meter with serum bilirubin estimation. Design: Analytical cross sectional study. Place and duration: NICU Military Hospital Rawalpindi Pakistan Jun 2002 to May 2005. Subjects and Methods: One hundred and fifty neonates admitted to NICU because of visible jaundice were included in the study. Serum was sent to laboratory for total bilirubin estimation. At the same time bilirubin was also checked by a Jaundice Meter. Data was tabulated and t-test applied to compare the two values. Results: One hundred and fifty paired estimations were performed. The transcutaneous bilirubin values ranged from 8.0 mg/dl to 20.4 mg/dl. While serum bilirubin by jaundice meter values ranged between 5.3 mg/dl and 26.0 mg/dl. A Scatter diagram was plotted. It showed a correlation coefficient of 0.78. Conclusion: Bilirubin values obtained by transcutaneous bilirubin meter were not significantly different from laboratory values thus proving the fact that transcutaneous bilirubinometer is a useful device to measure bilirubin. (author)

  17. Transcutaneous mechanical nerve stimulation using perineal vibration: a novel method for the treatment of female stress urinary incontinence

    DEFF Research Database (Denmark)

    Sønksen, Jens; Ohl, Dana A; Bonde, Birthe

    2007-01-01

    We defined basic guidelines for transcutaneous mechanical nerve stimulation in modifying pelvic floor responses in women and determined the efficacy of transcutaneous mechanical nerve stimulation in treating stress urinary incontinence.......We defined basic guidelines for transcutaneous mechanical nerve stimulation in modifying pelvic floor responses in women and determined the efficacy of transcutaneous mechanical nerve stimulation in treating stress urinary incontinence....

  18. Reactor vessel stud tensioner

    International Nuclear Information System (INIS)

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

    1982-01-01

    A quick-acting stud tensioner, for facilitating the loosening or tightening of a stud nut on a reactor vessel stud, has gripper jaws which when the tensioner is lowered into engagement with the upper end of the stud are moved inwards to grip the upper end and which when the tensioner is lifted move outward to release the upper end. (author)

  19. Trans-Cutaneous Bilirubinometery versus Serum Bilirubin in Neonatal Jaundice.

    Science.gov (United States)

    Mahram, Manoochehr; Oveisi, Sonia; Jaberi, Najmeh

    2015-12-01

    Hyperbilirubinemia is a common problem in neonates and causes serious complications. Thus, serial measurements of bilirubin should be done. This assessment is done through two methods of laboratory measurement in serum sample and transcutaneous bilirubinometer. This descriptive study compared transcutaneous bilirubin assessment and laboratory serum bilirubin. Bilirubin level was assessed among 256 neonates admitted to the Qods Children's Hospital in Qazvin- Iran, because of neonatal indirect jaundice, through two methods of transcutaneous bilirubinometery from two sites of forehead and sternum and laboratory measurement of bilirubin in serum. The cases were non-hemolytic icteric term neonates weighing 2500 gram or more and had not received phototherapy or other treatments. Neonates with hemolytic forms of jaundice, sepsis and suspicious to metabolic disorders were excluded. Assessments by means of KJ-8000 transcutaneous bilirubinometer from two sites of forehead and sternum and through laboratory measurement of serum bilirubin were registered and analyzed. The results of the current study showed that there was a correlation of 0.82 between serum bilirubin and transcutaneous forehead bilirubin assessment and for the used device sensitivity of 0.844; specificity of 0.842, Youden Index of 0.709 and Shortest of 0.042 for a cut-off of 12.4 in bilirubin of participants. Furthermore, Likelihood Ratio positive and negative (LR) were 5.665 and 0.164, respectively and diagnostic Odds Ratio (LR+/LR-) was 34.56. Transcutaneous bilirubinometery can be considered as a reliable tool to assess bilirubin for the screening of neonatal jaundice in term neonates.

  20. Transcutaneous electrical nerve stimulation and transcutaneous spinal electroanalgesia: a preliminary efficacy and mechanisms-based investigation.

    Science.gov (United States)

    Palmer, Shea; Cramp, Fiona; Propert, Kate; Godfrey, Helen

    2009-09-01

    To determine the effects of transcutaneous electrical nerve stimulation (TENS) and transcutaneous spinal electroanalgesia (TSE) on mechanical pain threshold (MPT) and vibration threshold (VT). A prospective, single-blind, randomised, placebo-controlled trial. Laboratory based. Thirty-four healthy volunteers (12 men and 22 women; mean age+/-standard deviation 30+/-8 years). Exclusion criteria were conditions affecting upper limb sensation and contraindications to electrical stimulation. Participants were allocated at random to receive TENS (n=8), TSE (n=8), placebo (n=9) or control (n=9). Electrical stimulation was applied for 30 minutes (from time 18 minutes to 48 minutes) via electrodes (5 cmx5 cm) placed centrally above and below the space between the C6 and C7 spinous processes, with 5 cm between electrodes. MPT (using an algometer) and VT (using a vibrameter) were recorded on seven occasions from the first dorsal interosseous muscle of the right hand - at baseline (0 minutes) and then at 10-minute intervals until the end of the 60-minute testing period. There were no statistically significant group differences in MPT (all p>0.05). Significant group differences in VT were found at 20, 30 and 40 minutes (all ptests showed that the TENS group had significantly greater VT than both the placebo [median difference 0.30 microm, 95% confidence interval (CI) -0.05 to 0.66] and control (0.51 microm, 95% CI 0.05 to 0.97) groups at 20 minutes, and significantly greater VT than the control group (0.69 microm, 95% CI 0.20 to 1.17) at 30 minutes (all p<0.008). Electrical stimulation did not alter MPT. The increase in VT during TENS may be due to distraction or antidromic block of large-diameter nerve fibres. TSE failed to alter either outcome measure significantly.

  1. [Value of transcutaneous staged dynamic oximetry of stage II arteritis of the leg].

    Science.gov (United States)

    Grard, C; Desmytterre, J; Vinckier, L; Hatron, P Y; Roux, J P; Warembourg, H; Devulder, B

    1990-03-01

    The clinical and prognostic value of transcutaneous oxygen pressure measurements at rest has been established in Leriche Stage III and IV occlusive peripheral arterial disease but is controversial in Stage II because there is an overlap of transcutaneous pO2 (Tc pO2) values with those of normal subjects. The authors report the results of Tc pO2 measurements during exercise testing in a group of patients with Stage II occlusive arterial disease of the lower limbs. Seventy-eight patients with an average age of 53 years (range 40 to 65 years) whose claudication perimeter and site of pain had been carefully assessed and who had also recently undergone Doppler arterial examination and arteriography and 35 control subjects with an average age of 54 years (range 45 to 70 years) were studied. The Tc pO2 was continuously measured with a multimodular Kontron Supermon at 4 different sites simultaneously: precordium (reference probe), thigh, calf and foot in the dorsal recumbent position after 30 minutes rest, during a standardised exercise stress test at 50 watts and during the recovery phase. The results were expressed as ratio of tissue oxygenation (RTO): thigh, calf or foot Tc pO2/precordial Tc pO2 X 100 in order to take into account the patients cardiorespiratory status and adaptation to exercise. The RTO in normal subjects remained at the upper limits of the resting value throughout exercise and then returned slowly to basal values during the recovery phase.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Mechanistic studies on transcutaneous vaccine delivery : microneedles, nanoparticles and adjuvants

    NARCIS (Netherlands)

    Bal, Suzanne Marleen

    2011-01-01

    Microneedle-based transcutaneous immunisation is an appealing alternative to the classical manner of injecting vaccines by intramuscular or subcutaneous route. Importantly, as a consequence of the fact that the skin is in direct contact with the environment and should protect the body against

  3. Transcutaneous drug delivery by liposomes using fractional laser technology.

    Science.gov (United States)

    Fujimoto, Takahiro; Wang, Jian; Baba, Kazuki; Oki, Yuka; Hiruta, Yuki; Ito, Masayuki; Ito, Shinobu; Kanazawa, Hideko

    2017-07-01

    Transdermal delivery of hydrophilic peptides remains a challenge due to their poor cellular uptake and transdermal penetration. We hypothesize that combination of a CO 2 fractional laser to enhance percutaneous absorption and liposomes as transdermal carriers would improve skin penetration of hydrophilic drugs. NA. Liposomes were prepared using membrane fusion lipid dioleoylphosphatidylethanolamine, and used to deliver 5-carboxyfluorescein (CF) and fluorescein isothiocyanate-conjugated ovalbumin (OVA-FITC) as model hydrophilic peptide drugs. Liposome size was estimated by dynamic light scattering. Liposome uptake into murine macrophage cells and penetration or permeation into Yucatan micropig skin after irradiation by CO 2 fractional laser at varying energy levels (laser power and exposure duration) were investigated using Franz cell and fluorescence microscopy. Oxidative damage to the irradiated mouse skin was assessed by electron spin resonance. Size of CF and OVA-FITC encapsulated liposomes was 324 ± 75 nm. Cellular uptake of OVA-FITC delivered by liposomes was 10-fold higher (1,370 relative fluorescence units, RFU) than delivered in solution form (130 RFU). Fractional laser irradiation increased skin permeation rate of CF liposomes (0-10%) and OVA-FITC liposomes (4-40%) in a dose-dependent manner. Although peeling off the stratum corneum facilitated CF liposome penetration at low energy levels (2.69-3.29 J/cm 2 ; 10-20 W for 500 μs), drug permeation was similar (7-8%) in peeled or untreated skin at higher laser energy levels (6.06 J/cm 2 ; 20 W for 1,500 μs). FITC penetrated deeper in the skin after laser irradiation. However, OH, O2-, and VC reactive oxygen species were generated upon irradiation of the skin with a fractional CO 2 laser. Increasing laser power and irradiation, time increased liposome uptake by cells and penetration of peptide drugs across the skin in a dose-dependent manner. High-energy CO 2 fractional laser overcomes the

  4. Tension type headache

    Directory of Open Access Journals (Sweden)

    Debashish Chowdhury

    2012-01-01

    Full Text Available Tension type headaches are common in clinical practice. Earlier known by various names, the diagnosis has had psychological connotations. Recent evidence has helped clarify the neurobiological basis and the disorder is increasingly considered more in the preview of neurologists. The classification, clinical features, differential diagnosis and treatment of tension type headache are discussed in this paper.

  5. Tensions in Distributed Leadership

    Science.gov (United States)

    Ho, Jeanne; Ng, David

    2017-01-01

    Purpose: This article proposes the utility of using activity theory as an analytical lens to examine the theoretical construct of distributed leadership, specifically to illuminate tensions encountered by leaders and how they resolved these tensions. Research Method: The study adopted the naturalistic inquiry approach of a case study of an…

  6. Optic nerve oxygenation

    DEFF Research Database (Denmark)

    Stefánsson, Einar; Pedersen, Daniella Bach; Jensen, Peter Koch

    2005-01-01

    The oxygen tension of the optic nerve is regulated by the intraocular pressure and systemic blood pressure, the resistance in the blood vessels and oxygen consumption of the tissue. The oxygen tension is autoregulated and moderate changes in intraocular pressure or blood pressure do not affect...... the optic nerve oxygen tension. If the intraocular pressure is increased above 40 mmHg or the ocular perfusion pressure decreased below 50 mmHg the autoregulation is overwhelmed and the optic nerve becomes hypoxic. A disturbance in oxidative metabolism in the cytochromes of the optic nerve can be seen...... at similar levels of perfusion pressure. The levels of perfusion pressure that lead to optic nerve hypoxia in the laboratory correspond remarkably well to the levels that increase the risk of glaucomatous optic nerve atrophy in human glaucoma patients. The risk for progressive optic nerve atrophy in human...

  7. Transcutaneous Noninvasive Device for the Responsive Delivery of Melatonin in Microgravity., Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Our goal is develop a smart, transcutaneous device for individualized circadian (sleep) therapy by responsive release of melatonin, in microgravity. Additionally,...

  8. Closed Loop Control of Oxygen Delivery and Oxygen Generation

    Science.gov (United States)

    2017-08-01

    were used for this study and were connected via a USB cable to allow communication. The ventilator was modified to allow closed loop control of oxygen...connected via a USB cable to allow communication. The ventilator was modified to allow closed loop control of oxygen based on the oxygen saturation...2017-4119, 28 Aug 2017. oximetry (SpO2) and intermittent arterial blood sampling for arterial oxygen tension (partial pressure of oxygen [PaO2]) and

  9. Transcutaneous Spinal Direct Current Stimulation (tsDCS

    Directory of Open Access Journals (Sweden)

    Filippo eCogiamanian

    2012-07-01

    Full Text Available In the past ten years renewed interest has centered on non-invasive transcutaneous weak direct currents applied over the scalp to modulate cortical excitability (brain polarization or transcranial direct current stimulation, tDCS. Extensive literature shows that tDCS induces marked changes in cortical excitability that outlast stimulation.Aiming at developing a new, non invasive, approach to spinal cord neuromodulation we assessed the after-effects of thoracic transcutaneous spinal DC stimulation (tsDCS on somatosensory potentials (SEPs evoked in healthy subjects by posterior tibial nerve (PTN stimulation. Our findings showed that thoracic anodal tsDCS depresses the cervico-medullary PTN-SEP component (P30 without eliciting adverse effects. tsDCS also modulates post-activation H-reflex dynamics. Later works further confirmed that transcutaneous electric fields modulate spinal cord function. Subsequent studies in our laboratory showed that tsDCS modulates the flexion reflex in the human lower limb. Besides influencing the laser evoked potentials, tsDCS increases pain tolerance in healthy subjects. Hence, though the underlying mechanisms remain speculative, tsDCS modulates activity in lemniscal, spinothalamic and segmental motor systems.Here we review currently available experimental evidence that non-invasive spinal cord stimulation influences spinal function in humans and argue that, by focally modulating spinal excitability, tsDCS could provide a novel therapeutic tool complementary to drugs and invasive spinal cord stimulation in managing various pathologic conditions, including pain.

  10. Immediate effects of tongue trills associated with transcutaneous electrical nerve stimulation (TENS).

    Science.gov (United States)

    Fabron, Eliana Maria Gradim; Petrini, Andressa Schweitzer; Cardoso, Vanessa de Moraes; Batista, João Carlos Torgal; Motonaga, Suely Mayumi; Marino, Viviane Cristina de Castro

    2017-06-08

    To investigate vocal quality variability after applying tongue trills associated with transcutaneous electrical nerve stimulation (TENS) on the larynx of women with normal laryngeal function. Additionally, to verify the effect of this technique over time on voice quality. Participants were 40 women (average 23.4 years) without vocal complaints. The procedure involved tongue trills with or without TENS for 3 minutes, rest and repeating the technique for another 2 minutes. The participants' voices were recorded before (Pre), after three minutes (Post 3min) and after two additional minutes (Post 5min) applying the technique. TENS with two electrodes was used on the thyroid cartilage. Self-assessment, acoustic and perceptual analysis were performed. When comparing tongue trills in isolation and associated with TENS, a greater sense of stability in phonation (self-assessment) and improvement in voice quality (perceptual evaluation) was observed in the combination technique. There was no statistical difference in acoustics findings between tongue trills in isolation and associated with TENS. When comparing the time effect of tongue trills with TENS in self-assessment there was a perception of less muscle tension (3min) and greater comfort during phonation (5 min); in the acoustic analysis, there was an increase of F0 (3 and 5 min) and intensity (5 min) when compared to Pre-moment; in the perceptual evaluation, better voice quality (3min). Comparing tongue trills in isolation and associated with TENS, there were changes in the comfort and muscle tension perception, as well as in vocal quality. On the other hand, tongue trills associated with TENS performed in 3 or 5 minutes resulted in beneficial effects on the voice identified in the assessments.

  11. Parachute Cord Tension Sensor

    Data.gov (United States)

    National Aeronautics and Space Administration — To design and fabricate a light weight (few oz), very small (~2 inch length) parachute cord tension sensor demonstrator device.A major challenge for the CPAS (The...

  12. Leadership. Using Creative Tension.

    Science.gov (United States)

    Cook, David L.

    1986-01-01

    Leadership involves maintaining a balance of the variables which comprise leadership. Love and fear, types of power, success and effectiveness, and driving and restraining forces are discussed as sources of the creative tension a leader uses to influence others. (MT)

  13. Spontaneous tension haemopneumothorax

    OpenAIRE

    Patterson, Benjamin Oliver; Itam, Sarah; Probst, Fey

    2008-01-01

    Abstract We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such c...

  14. 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.

  15. 21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

    Science.gov (United States)

    2010-04-01

    ... pain relief. 882.5890 Section 882.5890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to...

  16. The Neuroprotection Effect of Oxygen Therapy: A Systematic Review ...

    African Journals Online (AJOL)

    2018-04-04

    Apr 4, 2018 ... investigating the neuroprotective effect of oxygen, but the outcomes as well as ...... Neuroprotective gases – Fantasy or reality for clinical use? Prog .... of oxygen on brain tissue oxygen tension in children with severe traumatic ...

  17. Comparison of arterial blood gas with continuous intra-arterial and transcutaneous PO2 sensors in adult critically ill patients.

    Science.gov (United States)

    Green, G E; Hassell, K T; Mahutte, C K

    1987-05-01

    We compared the partial pressure of oxygen directly via a continuous intra-arterial probe (PiaO2) and indirectly using a transcutaneous device (PtcO2) with simultaneously obtained arterial blood PaO2. The PiaO2 values were measured using a bipolar oxygen sensor placed through an 18-ga arterial catheter. The PtcO2 values were measured using a transcutaneous O2-CO2 sensor placed on the abdomen. Seven critically ill, hemodynamically stable, ventilator-dependent adult patients were studied. Measurements were obtained at varying concentrations (0.25 to 1.0) of inspired oxygen after a 10-min stabilization. A total of 78 simultaneous values were obtained; by linear regression: PiaO2 = 0.91 PaO2 + 1.39 (r = .98, standard errors of the estimate [SEE] = 18.6); PtcO2 = 0.39 PaO2 + 36.2 (r = .89, SEE = 14.1). To assess these instruments as trend monitors, we compared the changes in simultaneous PaO2, PiaO2, and PtcO2 values; by linear regression: delta PiaO2 = 0.90 delta PaO2 + 3.88 (r = .96, SEE = 27.7); delta PtcO2 = 0.43 delta PaO2 + 5.6 (r = .94, SEE = 15.2). We conclude that, although these instruments correlate highly with the PaO2, the SEE was substantial and therefore may limit their clinical reliability in adults. Any acute or clinically significant change in PiaO2 or PtcO2 should be confirmed with a blood gas PaO2.

  18. Spontaneous tension haemopneumothorax.

    Science.gov (United States)

    Patterson, Benjamin Oliver; Itam, Sarah; Probst, Fey

    2008-10-31

    We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such case reported.Aetiology and current approach to spontaneous haemothorax are discussed briefly.

  19. Spontaneous tension haemopneumothorax

    Directory of Open Access Journals (Sweden)

    Itam Sarah

    2008-10-01

    Full Text Available Abstract We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such case reported. Aetiology and current approach to spontaneous haemothorax are discussed briefly.

  20. Creating Tension in Writing.

    Science.gov (United States)

    Folta, Bernarr

    This paper discusses the rationale and teaching methods for a six-week unit, for a high school freshman English Class, on perception, semantics, and writing, which places special focus on developing tension in student writing. The first four objectives of the course focus on perception and the next two focus on semantics. The seventh…

  1. Tension-filled Governance?

    DEFF Research Database (Denmark)

    Celik, Tim Holst

    on the statesituated tension-filled functional relationship between legitimation and accumulation, the study both historically and theoretically reworks this approach and reapplies it for the post-1970s/1990s governance period. It asks whether and to what extent governance has served as a distinctive post- 1970s/1990s...

  2. Rein tension during canter

    NARCIS (Netherlands)

    Egenvall, Agneta; Eisersiö, Marie; Rhodin, Marie; van Weeren, P.R.; Roepstorff, Lars

    2015-01-01

    Riders generally use reins as a means for communication with the horse. At present, the signalling pattern is poorly understood. The aim of this study was to illustrate and analyse the rein tension patterns in a number of rider/horse combinations across a variety of exercises in the canter gait. Our

  3. Transcutaneous Bilirubin Nomogram for Healthy Term and Late Preterm Neonates in First 96 Hours of Life.

    Science.gov (United States)

    Thakkar, Pareshkumar; Chavda, Hardas; Doshi, Vikas

    2017-05-15

    To develop nomogram of Transcutaneous Bilirubin among healthy term and late-preterm neonates during first 96 hours of age. Longitudinal observational study. Neonatal unit of a tertiary care Hospital of Central Gujarat, India. 1075 healthy term and late preterm neonates (≥35weeks). Six-hourly transcutaneous bilirubin was obtained from birth to 96 hour of life using Drager JM 103 Transcutaneous Bilirubinometer. Main outcome measures: Nomogram of Transcutaneous Bilirubin with percentile values was obtained, rate of rise of bilirubin was calculated and predictive ability of normative data was analyzed for subsequent need of phototherapy. The age-specific percentile curves and nomogram were developed from the transcutaneous bilirubin readings of 1,010 neonates. Rate of rise in first 12 hour was 0.2 mg/dL and was 0.17 mg/dL in 12 to 24 hour of life which decreased on second day of life. Neonates who required phototherapy had consistently higher readings of transcutaneous bilirubin and also higher rate of rise in first 48 hrs. Neonates whose transcutaneous bilirubin is above the 50th percentile should be monitored for the development of significant hyperbilirubinemia.

  4. WITHDRAWN: Transcutaneous electrical nerve stimulation and acupuncture-like transcutaneous electrical nerve stimulation for chronic low back pain.

    Science.gov (United States)

    Gadsby, J G; Flowerdew, M W

    2007-07-18

    In view of the claims and counter-claims of the effectiveness of transcutaneous electrical nerve stimulation, it would seem appropriate to systematically review the literature. To determine the effectiveness of transcutaneous electrical nerve stimulation in reducing pain and improving range of movement in patients with chronic low back pain. Electronic searches of EMBASE, MEDLINE, CISCOM, AMED for all studies of TENS in the English language, identifying those treating chronic low back pain and hand searching their references. The inclusion criterion for studies included in this review, 6 of 68 identified, was comparisons of TENS/ALTENS versus placebo in patients with chronic low back pain. Outcome data on pain reduction, range of movement, functional status and work was extracted by two independent reviewers together with trial design qualities to construct a Quality Index. The ratio of odds of improvement in pain for each comparison was calculated: TENS vs. placebo at 1.62 (95% CI 0.90, 2.68); ALTENS vs. placebo at 7.22 (95% CI 2.60, 20.01) and TENS/ALTENS vs. placebo at 2.11 (95% CI 1.32, 3.38) times that of placebo. An improvement in pain reduction was seen in 45.80% (CI 37.00%, 55.00%) of TENS; 86.70% (CI 80.00%, 93.00%) of ALTENS; 54.00% (CI 46.20%, 61.80%) of TENS/ ALTENS and 36.40% (95%CI 28.40%, 44.40%) of placebo subjects. The odds of improvement in range of movement on ALTENS vs. placebo was 6.61 times (95% CI 2.36, 18.55) that of placebo. Transcutaneous electrical nerve stimulation appears to reduce pain and improve the range of movement in chronic low back pain subjects. A definitive randomised controlled study of ALTENS, TENS, placebo/no treatment controls, of sufficient power, is needed to confirm these findings.

  5. Coulomb string tension, asymptotic string tension, and the gluon chain

    OpenAIRE

    Greensite, Jeff; Szczepaniak, Adam P.

    2014-01-01

    We compute, via numerical simulations, the non-perturbative Coulomb potential of pure SU(3) gauge theory in Coulomb gauge. We find that that the Coulomb potential scales nicely in accordance with asymptotic freedom, that the Coulomb potential is linear in the infrared, and that the Coulomb string tension is about four times larger than the asymptotic string tension. We explain how it is possible that the asymptotic string tension can be lower than the Coulomb string tension by a factor of four.

  6. Low impedance pH sensitive electrochemical devices that are potentially applicable to transcutaneous PCO2 measurements.

    Science.gov (United States)

    Yeung, H N; Beran, A V; Huxtable, R F

    1978-01-01

    Two cases of low impedance, non-glass membrane electrodes for pH measurement were evaluated: (I) Metal--metal oxide electrodes and (II) Reduction-oxidation electrodes. The fundamental cause of oxygen sensitivity of metal-metal oxide electrodes were examined and three approaches for its suppression were proposed. For the case of Sb--Sb2Ox electordes, oxygen sensitivity can be attenuated partially by cell loading, either directly across the reference electrode or indirectly across a third slave electrode. In a PO2 range of 8--54 kPa, more than 95% of the PO2 response can be suppressed by loading the cell emf to half of tis open-circuit value. The oxygen sensitivity also was observed to diminished by grinding the metal-metal oxide and pressing it under high pressure into a pellet electrode. Other metal-metal oxide electrodes that have promise in transcutaneous measurement are the Pd-PdO2 electrodes. The redox electrodes are typified by the Quinhydrone electrode. A membrane Quinhydrome electrode showed a sensitivity of 56 mV/Decade at 37 degree C and no oxygen sensitivity up to 50 kPa and a drift of 1 mV/h over a 24-h period. However, the stability deteriorated over a long-term period.

  7. Transcutaneous Electrical Nerve Stimulation (TENS) and Laryngeal Manual Therapy (LMT): Immediate Effects in Women With Dysphonia.

    Science.gov (United States)

    Conde, Mariana de Cásisa Macedo; Siqueira, Larissa Thaís Donalonso; Vendramini, José Eduardo; Brasolotto, Alcione Ghedini; Guirro, Rinaldo Roberto de Jesus; Silverio, Kelly Cristina Alves

    2018-05-01

    This study aimed to verify the immediate effect of low-frequency transcutaneous electrical nerve stimulation (TENS) and laryngeal manual therapy (LMT) in musculoskeletal pain, voice quality, and self-reported signs in women with dysphonia. Thirty women with behavioral dysphonia were randomly divided into the TENS group and the LMT group. All participants fulfilled the pain survey and had their voices recorded to posterior perceptual and acoustic analysis before and after intervention. The TENS group received a unique low-frequency TENS session (20 minutes). The LMT group received LMT (20 minutes) with soft and superficial massage in the sternocleidomastoid muscle, suprahyoid muscles, and larynx. Afterward, the volunteers reported their voice, larynx, breathing, and articulatory signs. Pre and post data were compared by parametric and nonparametric tests. After TENS, a decrease in pain intensity in the posterior or anterior region of the neck, shoulders, upper or lower back, and masseter was observed. After LMT, a decrease in pain intensity in the neck anterior region, shoulders, lower back, and temporal region was observed. Also, after TENS, there was an improvement in vowel /a/ instability; after LMT, there was a general improvement in voice quality, decrease in tension, and decrease in breathiness in speech. Positive voice and laryngeal signs were reported after TENS, and positive laryngeal signs and articulation were reported after LMT. TENS and LMT may be used in voice treatment of women with behavioral dysphonia, and both may be considered important therapy resources that reduce musculoskeletal pain and cause positive laryngeal signs. Both TENS and LMT are able to partially improve voice quality, but TENS presented better results. Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  8. Oxygen, nitric oxide and articular cartilage

    Directory of Open Access Journals (Sweden)

    B Fermor

    2007-04-01

    Full Text Available Molecular oxygen is required for the production of nitric oxide (NO, a pro-inflammatory mediator that is associated with osteoarthritis and rheumatoid arthritis. To date there has been little consideration of the role of oxygen tension in the regulation of nitric oxide production associated with arthritis. Oxygen tension may be particularly relevant to articular cartilage since it is avascular and therefore exists at a reduced oxygen tension. The superficial zone exists at approximately 6% O2, while the deep zone exists at less than 1% O2. Furthermore, oxygen tension can alter matrix synthesis, and the material properties of articular cartilage in vitro.The increase in nitric oxide associated with arthritis can be caused by pro-inflammatory cytokines and mechanical stress. Oxygen tension significantly alters endogenous NO production in articular cartilage, as well as the stimulation of NO in response to both mechanical loading and pro-inflammatory cytokines. Mechanical loading and pro-inflammatory cytokines also increase the production of prostaglandin E2 (PGE2. There is a complex interaction between NO and PGE2, and oxygen tension can alter this interaction. These findings suggest that the relatively low levels of oxygen within the joint may have significant influences on the metabolic activity, and inflammatory response of cartilage as compared to ambient levels. A better understanding of the role of oxygen in the production of inflammatory mediators in response to mechanical loading, or pro-inflammatory cytokines, may aid in the development of strategies for therapeutic intervention in arthritis.

  9. The influence of transcutaneous electrical neurostimulation (TENS) on human cerebral blood flow velocities

    NARCIS (Netherlands)

    ter Laan, Mark; van Dijk, J. Marc C.; Elting, Jan-Willem J.; Fidler, Vaclav; Staal, Michiel J.

    It has been shown that transcutaneous electrical neurostimulation (TENS) reduces sympathetic tone. Spinal cord stimulation (SCS) has proven qualities to improve coronary, peripheral, and cerebral blood circulation. Therefore, we postulate that TENS and SCS affect the autonomic nervous system in

  10. Comparison of Transcutaneous Bilirubin Measurement With Total Serum Bilirubin Levels in Preterm Neonates Receiving Phototherapy.

    Science.gov (United States)

    Pendse, Amruta; Jasani, Bonny; Nanavati, Ruchi; Kabra, Nandkishor

    2017-08-15

    To compare transcutaneous bilirubin with total serum bilirubin in preterm neonates after initiation of phototherapy. Jaundice was assessed in 30 preterm neonates with transcutaneous bilirubin and total serum bilirubin before initiation of phototherapy and at 12 hr after initiation of phototherapy. A photo-occlusive patch was applied over the sternum. Transcutaneous bilirubin has a good correlation with total serum bilirubin after initiation of phototherapy. (r=0.918, Pbilirubin at 28-32 weeks of gestation (r = 0.97) was better correlated with total serum bilirubin than those at 32-37 weeks (r =0.88). The correlation was better for neonates 72 hours of age (r = 0.82). Transcutaneous bilirubin correlates significantly with total serum bilirubin at the patched sternal site after initiation of phototherapy in preterm neonates.

  11. Effect of transcutaneous electrical muscle stimulation on muscle volume in patients with septic shock

    DEFF Research Database (Denmark)

    Poulsen, Jesper Brøndum; Møller, Kirsten; Jensen, Claus V

    2011-01-01

    Objective: Intensive care unit admission is associated with muscle wasting and impaired physical function. We investigated the effect of early transcutaneous electrical muscle stimulation on quadriceps muscle volume in patients with septic shock. Design: Randomized interventional study using...

  12. Transcutaneous periorbital electrical stimulation in the treatment of dry eye.

    Science.gov (United States)

    Pedrotti, Emilio; Bosello, Francesca; Fasolo, Adriano; Frigo, Anna C; Marchesoni, Ivan; Ruggeri, Alfredo; Marchini, Giorgio

    2017-06-01

    To evaluate efficacy and safety of transcutaneous application of electrical current on symptoms and clinical signs of dry eye (DE). 27 patients with DE underwent transcutaneous electrostimulation with electrodes placed onto the periorbital region of both eyes and manual stimulation with a hand-piece conductor moved by the operator. Each patient underwent 12 sessions of 22 min spread over 2 months, two sessions per week in the first month and one session per week in the second month. Ocular Surface Disease Index (OSDI) questionnaire, tear break-up time (TBUT), fluorescein staining of the cornea, Schirmer I test and adverse events were evaluated at baseline, at end of treatment and at 6 and 12 months. OSDI improved from 43.0±19.2 at baseline to 25.3±22.1 at end of treatment (mean±SD, p=0.001). These effects were substantially maintained at 6-month and 12-month follow-up evaluations. Improvement of the values of TBUT was recorded for the right eye at the end of treatment (p=0.003) and found in the left eye after 12 months (p=0.02). The Oxford scores changed in both eyes at the end of treatment and at the 6-month evaluation (peye at the 12-month evaluation (p=0.035). Schirmer I improved significantly at the end of treatment in the left eye (p=0.001) and in both eyes at the 12-month evaluation (p=0.004 and p=0.039 for the left and right eye, respectively). A significant reduction of the use of tear substitutes was found at the end of treatment (p=0.003), and was maintained during the follow-up (ptreatment satisfying. Transcutaneous electrical stimulation was shown to improve DE, both subjectively and objectively, without any adverse effects and has the potential to enlarge the armamentarium for treating DE. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  13. Medical devices; neurological devices; classification of the transcutaneous electrical nerve stimulator to treat headache. Final order.

    Science.gov (United States)

    2014-07-03

    The Food and Drug Administration (FDA) is classifying the transcutaneous electrical nerve stimulator to treat headache into class II (special controls). The special controls that will apply to the device are identified in this order, and will be part of the codified language for the transcutaneous electrical nerve stimulator to treat headache classification. The Agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device.

  14. Transcutaneous electric nerve stimulation (TENS) in dentistry- A review.

    Science.gov (United States)

    Kasat, Vikrant; Gupta, Aditi; Ladda, Ruchi; Kathariya, Mitesh; Saluja, Harish; Farooqui, Anjum-Ara

    2014-12-01

    Transcutaneous electric nerve stimulation (TENS) is a non-pharmacological method which is widely used by medical and paramedical professionals for the management of acute and chronic pain in a variety of conditions. Similarly, it can be utilized for the management of pain during various dental procedures as well as pain due to various conditions affecting maxillofacial region. This review aims to provide an insight into clinical research evidence available for the analgesic and non analgesic uses of TENS in pediatric as well as adult patients related to the field of dentistry. Also, an attempt is made to briefly discuss history of therapeutic electricity, mechanism of action of TENS, components of TENs equipment, types, techniques of administration, advantages and contradictions of TENS. With this we hope to raise awareness among dental fraternity regarding its dental applications thereby increasing its use in dentistry. Key words:Dentistry, pain, TENS.

  15. Does transcutaneous nerve stimulation have effect on sympathetic skin response?

    Science.gov (United States)

    Okuyucu, E Esra; Turhanoğlu, Ayşe Dicle; Guntel, Murat; Yılmazer, Serkan; Savaş, Nazan; Mansuroğlu, Ayhan

    2018-01-01

    This study examined the effects of transcutaneous electrical nerve stimulation (TENS) on the sympathetic nerve system by sympathetic skin response test. Fifty-five healthy volunteers received either: (i) 30minutes TENS (25 participants) (ii) 30minutes sham TENS (30 participants) and SSR test was performed pre- and post-TENS. The mean values of latency and peak-to-peak amplitude of five consecutive SSRs were calculated. A significant amplitude difference was found between TENS and sham TENS group both in right and left hand (p=0.04, p=0.01, respectively). However there was no significant latancy difference between two groups (p>0.05 ). TENS has an inhibitory effect on elicited SNS responses when compared with sham TENS control group. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Fixed-site high-frequency transcutaneous electrical nerve stimulation for treatment of chronic low back and lower extremity pain

    OpenAIRE

    Gozani, Shai

    2016-01-01

    Shai N Gozani NeuroMetrix, Inc., Waltham, MA, USA Objective: The objective of this study was to determine if fixed-site high-frequency transcutaneous electrical nerve stimulation (FS-TENS) is effective in treating chronic low back and lower extremity pain. Background: Transcutaneous electrical nerve stimulation is widely used for treatment of chronic pain. General-purpose transcutaneous electrical nerve stimulation devices are designed for stimulation anywhere on the body and often cannot be ...

  17. Tension-type headache

    DEFF Research Database (Denmark)

    Bendtsen, Lars; Jensen, Rigmor; Bendtsen, Lars

    2009-01-01

    The substantial societal and individual burdens associated with tension-type headache (TTH) constitute a previously overlooked major public health issue. TTH is prevalent, affecting up to 78% of the general population, and 3% suffer from chronic TTH. Pericranial myofascial nociception probably...... is important for the pathophysiology of episodic TTH, whereas sensitization of central nociceptive pathways seems responsible for the conversion of episodic to chronic TTH. Headache-related disability usually can be reduced by identification of trigger factors combined with nonpharmacologic and pharmacologic...... treatments, but effective treatment modalities are lacking. Benefits can be gained by development of specific and effective treatment strategies....

  18. Transcutaneous electrical nerve stimulation and acupuncture-like transcutaneous electrical nerve stimulation for chronic low back pain.

    Science.gov (United States)

    Gadsby, J G; Flowerdew, M W

    2000-01-01

    Transcutaneous electrical nerve stimulation (TENS), originally based on the gate-control theory of pain, is widely used for the treatment of chronic low back pain. Despite its wide use and theoretical rationale, there appears at first glance little scientific evidence to support its use. This Cochrane review examines the available evidence on TENS for the treatment of chronic back pain through an exhaustive search of the literature. Transcutaneous electrical nerve stimulation (TENS) and acupuncture-like transcutaneous electrical nerve stimulation (ALTENS) for chronic low back pain management have experienced a tremendous growth over the past 25 years. The objective of this review was to assess the effects of TENS and ALTENS for reducing pain and improving function in patients with chronic back pain. We searched MEDLINE up to November 1997, EMBASE from 1985 to September 1995, Amed and Ciscom to January 1995, reference lists of the retrieved articles, proceedings of conferences and contacted investigators in the field. Randomised trials comparing TENS or ALTENS therapy to placebo in patients with chronic low back pain. Two reviewers independently assessed trial quality and extracted data on pain reduction, range of movement, functional and work status. Six trials were included. The trials included 288 participants with an average age range of 45 to 50 years and approximately equal numbers of women and men. The overall odds ratio for improvement in pain for each comparison was: TENS/ALTENS versus placebo 2.11 (95% confidence interval 1.32 to 3. 38), ALTENS versus placebo 7.22 (95% confidence interval 2.60 to 20.01) and TENS versus placebo 1.52 (95% confidence interval 0.90 to 2.58). The odds ration for improvement in range of motion on ALTENS versus placebo was 6.61 (95% confidence interval 2.36 to 18.55). There is evidence from the limited data available that TENS/ALTENS reduces pain and improves range of motion in chronic back pain patients, at least in the short

  19. Transcutaneous oximetry compared to ankle-brachial-index measurement in the evaluation of percutaneous transluminal angioplasty

    International Nuclear Information System (INIS)

    Wildgruber, Moritz; Wolf, Oliver; Weiss, Wolfgang; Berger, Hermann; Lutzenberger, Werner; Eckstein, Hans-Henning; Heider, Peter

    2007-01-01

    Objective: To investigate transcutaneous oximetry as parameter of the microcirculation is correlated to ankle-brachial-index as parameter of the macrocirculation after peripheral angioplasty procedures. Design: Prospective study. Materials and methods: 60 patients suffering from intermittent claudication were scheduled for angioplasty treatment. 45 patients were considered as eligible for angioplasty after angiographic evaluation, 15 patients underwent angiography only. Transcutaneous oximetry measurements were performed before the procedure, at the end of intervention, 24 h as well as 2 and 4 weeks after percutaneous transluminal angioplasty. Ankle-brachial-indices were obtained before intervention, 24 h as well as 2 and 4 weeks later. Results: Ankle-brachial-indices increased significantly at 24 h after angioplasty in patients being treated with angioplasty. Transcutaneous oximetry values dropped significantly at the end of the procedure and returned close to the baseline levels at 2 and 4 weeks after angioplasty. Ankle-brachial-indices and transcutaneous oximetry were positively correlated before (r = 0.3833, p = 0.009) as well as 4 weeks after angioplasty (r = 0.4596, p = 0.001). Immediately after radiological interventions, ankle-brachial-indices and transcutaneous oximetry are not positively correlated. In patients undergoing angiography only, transcutaneous oximetry levels drop significantly immediately after angiography and remain at decreased levels even at 4 weeks after intervention. Conclusion: Transcutaneous oximetry as parameter of the microcirculation is positively correlated with ankle-brachial-index as parameter of the macrocirculation before and at 4 weeks after angioplasty. Intraarterial angiography leads to a sudden decrease in skin microcirculation without affecting macrocirculation. As indicated by a lack of recovery in transcutaneous oximetry levels after 4 weeks, angiography alone results in a prolonged impaired microcirculation which may

  20. General definition of gravitational tension

    International Nuclear Information System (INIS)

    Harmark, T.; Obers, N.A.

    2004-01-01

    In this note we give a general definition of the gravitational tension in a given asymptotically translationally-invariant spatial direction of a space-time. The tension is defined via the extrinsic curvature in analogy with the Hawking-Horowitz definition of energy. We show the consistency with the ADM tension formulas for asymptotically-flat space-times, in particular for Kaluza-Klein black hole solutions. Moreover, we apply the general tension formula to near-extremal branes, constituting a check for non-asymptotically flat space-times. (author)

  1. Bilateral tension pneumothorax related to acupuncture.

    Science.gov (United States)

    Tagami, Rumi; Moriya, Takashi; Kinoshita, Kosaku; Tanjoh, Katsuhisa

    2013-06-01

    We report on a patient with a rare case of bilateral tension pneumothorax that occurred after acupuncture. A 69-year-old large-bodied man, who otherwise had no risk factors for spontaneous pneumothorax, presented with chest pressure, cold sweats and shortness of breath. Immediately after bilateral pneumothorax had been identified on a chest radiograph in the emergency room, his blood pressure and percutaneous oxygen saturation suddenly decreased to 78 mm Hg and 86%, respectively. We confirmed deterioration in his cardiopulmonary status and diagnosed bilateral tension pneumothorax. We punctured his chest bilaterally and inserted chest tubes for drainage. His vital signs promptly recovered. After the bilateral puncture and drainage, we learnt that he had been treated with acupuncture on his upper back. We finally diagnosed a bilateral tension pneumothorax based on the symptoms that appeared 8 h after the acupuncture. Because the patient had no risk factors for spontaneous pneumothorax, no alternative diagnosis was proposed. We recommend that patients receiving acupuncture around the chest wall must be adequately informed of the possibility of complications and expected symptoms, as a definitive diagnosis can be difficult without complete information.

  2. Tension type headaches: a review

    African Journals Online (AJOL)

    Location of the pain:There is often a typical location for tension- type headaches, as ... Cranial nerve abnormalities, including papilloedema. • Signs of ... peripheral and central mechanisms underlie tension-type ... Physiotherapy has been shown to be an effective management option for .... Acupuncture in primary headache.

  3. Early predictive value of cord blood bilirubin and dynamic monitoring of transcutaneous bilirubin for hyperbilirubinemia of newborns

    Directory of Open Access Journals (Sweden)

    Haishan Guan

    2017-12-01

    Conclusions: The increase of cord blood bilirubin effectively predict the occurrence of neonatal hyperbilirubinemia. There is a good correlation between levels of transcutaneous bilirubin and serum bilirubin. Moreover, combined detection of transcutaneous bilirubin and cord blood bilirubin can significantly improve the prediction accuracy of hyperbilirubinemia.

  4. Inadequate cerebral oxygen delivery and central fatigue during strenuous exercise

    DEFF Research Database (Denmark)

    Nybo, Lars; Rasmussen, Peter

    2007-01-01

    Under resting conditions, the brain is protected against hypoxia because cerebral blood flow increases when the arterial oxygen tension becomes low. However, during strenuous exercise, hyperventilation lowers the arterial carbon dioxide tension and blunts the increase in cerebral blood flow, which...... can lead to an inadequate oxygen delivery to the brain and contribute to the development of fatigue....

  5. MUSCLE TENSION DYSPHONIA

    Directory of Open Access Journals (Sweden)

    Irena Hočevar Boltežar

    2004-07-01

    Full Text Available Background. Muscle tension dysphonia (MTD is the cause of hoarseness in almost one half of the patients with voice disorders. The otorhinolaryngologic examination discovers no evident organic lesions in the larynx at least in the beginning of the voice problems. The reason for the hoarse voice is a disordered and maladjusted activity of the muscles taking part in phonation and/or articulation. In some patients, the irregular function of the larynx results in mucosal lesions on vocal folds. The factors participating in the development of MTD, directly or indirectly influence the quality of laryngeal mucosa, the activity of the phonatory muscles and/or increase of the vocal load. In the diagnostics and treatment of the MTD a phoniatrician, a speech and language therapist and a psychologist closely cooperate with the patient who must take an active role. The treatment is a long-lasting one but resulted in a high percentage of clinical success.Conclusions. Most likely, MTD is not a special disease but only a reflection of any disorder in the complicated system of regulation and realization of phonation. The prognosis of treatment is good when all unfavourable factors participating in development of MTD are eliminated and a proper professional voice- and psychotherapy started.

  6. Coated microneedle arrays for transcutaneous delivery of live virus vaccines.

    Science.gov (United States)

    Vrdoljak, Anto; McGrath, Marie G; Carey, John B; Draper, Simon J; Hill, Adrian V S; O'Mahony, Conor; Crean, Abina M; Moore, Anne C

    2012-04-10

    Vaccines are sensitive biologics that require continuous refrigerated storage to maintain their viability. The vast majority of vaccines are also administered using needles and syringes. The need for cold chain storage and the significant logistics surrounding needle-and-syringe vaccination is constraining the success of immunization programs. Recombinant live viral vectors are a promising platform for the development of vaccines against a number of infectious diseases, however these viruses must retain infectivity to be effective. Microneedles offer an effective and painless method for delivery of vaccines directly into skin that in the future could provide solutions to current vaccination issues. Here we investigated methods of coating live recombinant adenovirus and modified vaccinia virus Ankara (MVA) vectors onto solid microneedle arrays. An effective spray-coating method, using conventional pharmaceutical processes, was developed, in tandem with suitable sugar-based formulations, which produces arrays with a unique coating of viable virus in a dry form around the shaft of each microneedle on the array. Administration of live virus-coated microneedle arrays successfully resulted in virus delivery, transcutaneous infection and induced an antibody or CD8(+) T cell response in mice that was comparable to that obtained by needle-and-syringe intradermal immunization. To our knowledge, this is the first report of successful vaccination with recombinant live viral vectored vaccines coated on microneedle delivery devices. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Transcutaneous vagus nerve stimulation (tVNS) enhances divergent thinking.

    Science.gov (United States)

    Colzato, Lorenza S; Ritter, Simone M; Steenbergen, Laura

    2018-03-01

    Creativity is one of the most important cognitive skills in our complex and fast-changing world. Previous correlative evidence showed that gamma-aminobutyric acid (GABA) is involved in divergent but not convergent thinking. In the current study, a placebo/sham-controlled, randomized between-group design was used to test a causal relation between vagus nerve and creativity. We employed transcutaneous vagus nerve stimulation (tVNS), a novel non-invasive brain stimulation technique to stimulate afferent fibers of the vagus nerve and speculated to increase GABA levels, in 80 healthy young volunteers. Creative performance was assessed in terms of divergent thinking (Alternate Uses Task) and convergent thinking tasks (Remote Associates Test, Creative Problem Solving Task, Idea Selection Task). Results demonstrate active tVNS, compared to sham stimulation, enhanced divergent thinking. Bayesian analysis reported the data to be inconclusive regarding a possible effect of tVNS on convergent thinking. Therefore, our findings corroborate the idea that the vagus nerve is causally involved in creative performance. Even thought we did not directly measure GABA levels, our results suggest that GABA (likely to be increased in active tVNS condition) supports the ability to select among competing options in high selection demand (divergent thinking) but not in low selection demand (convergent thinking). Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. [Mechanisms and applications of transcutaneous electrical nerve stimulation in analgesia].

    Science.gov (United States)

    Tang, Zheng-Yu; Wang, Hui-Quan; Xia, Xiao-Lei; Tang, Yi; Peng, Wei-Wei; Hu, Li

    2017-06-25

    Transcutaneous electrical nerve stimulation (TENS), as a non-pharmacological and non-invasive analgesic therapy with low-cost, has been widely used to relieve pain in various clinical applications, by delivering current pulses to the skin area to activate the peripheral nerve fibers. Nevertheless, analgesia induced by TENS varied in the clinical practice, which could be caused by the fact that TENS with different stimulus parameters has different biological mechanisms in relieving pain. Therefore, to advance our understanding of TENS in various basic and clinical studies, we discussed (1) neurophysiological and biochemical mechanisms of TENS-induced analgesia; (2) relevant factors that may influence analgesic effects of TENS from the perspectives of stimulus parameters, including stimulated position, pulse parameters (current intensity, frequency, and pulse width), stimulus duration and used times in each day; and (3) applications of TENS in relieving clinical pain, including post-operative pain, chronic low back pain and labor pain. Finally, we propose that TENS may involve multiple and complex psychological neurophysiological mechanisms, and suggest that different analgesic effects of TENS with different stimulus parameters should be taken into consideration in clinical applications. In addition, to optimize analgesic effect, we recommend that individual-based TENS stimulation parameters should be designed by considering individual differences among patients, e.g., adaptively adjusting the stimulation parameters based on the dynamic ratings of patients' pain.

  9. Transcutaneous electrical nerve stimulation therapy in reduction of orofacial pain

    Directory of Open Access Journals (Sweden)

    Đorđević Igor

    2014-01-01

    Full Text Available Introduction. Patients with craniomandibular disorders suffer from hypertonic, fatigued and painful masticatory muscles. This condition can lead to limitation of mandibular jaw movements. All of these symptoms and signs are included in myofascial pain dysfunction syndrome. Transcutaneous electrical nerve stimulation (TENS has been used for treatment of these patients. Objective. The aim of this study was to assess the effect of TENS therapy on chronic pain reduction in patients with the muscular dysfunction symptom. Methods. In order to evaluate the effect of TENS therapy before and after the treatment, Craniomandibular Index (Helkimo was used. Pain intensity was measured by VAS. Patients had TENS treatment over two-week period. BURST TENS modality was used. Current intensity was individually adjusted. Results. Two patients did not respond to TENS therapy. Complete pain reduction was recorded in 8 patients, while pain reduction was not significantly different after TENS therapy in 10 patients. Conclusion. TENS therapy was confirmed as therapeutic procedure in orofacial muscle relaxation and pain reduction.

  10. Coated microneedle arrays for transcutaneous delivery of live virus vaccines

    Science.gov (United States)

    Vrdoljak, Anto; McGrath, Marie G.; Carey, John B.; Draper, Simon J.; Hill, Adrian V.S.; O’Mahony, Conor; Crean, Abina M.; Moore, Anne C.

    2016-01-01

    Vaccines are sensitive biologics that require continuous refrigerated storage to maintain their viability. The vast majority of vaccines are also administered using needles and syringes. The need for cold chain storage and the significant logistics surrounding needle-and-syringe vaccination is constraining the success of immunization programs. Recombinant live viral vectors are a promising platform for the development of vaccines against a number of infectious diseases, however these viruses must retain infectivity to be effective. Microneedles offer an effective and painless method for delivery of vaccines directly into skin that in the future could provide solutions to current vaccination issues. Here we investigated methods of coating live recombinant adenovirus and modified vaccinia virus Ankara (MVA) vectors onto solid microneedle arrays. An effective spray-coating method, using conventional pharmaceutical processes, was developed, in tandem with suitable sugar-based formulations, which produces arrays with a unique coating of viable virus in a dry form around the shaft of each microneedle on the array. Administration of live virus-coated microneedle arrays successfully resulted in virus delivery, transcutaneous infection and induced an antibody or CD8+ T cell response in mice that was comparable to that obtained by needle-and-syringe intradermal immunization. To our knowledge, this is the first report of successful vaccination with recombinant live viral vectored vaccines coated on microneedle delivery devices. PMID:22245683

  11. Transcutaneous electrical nerve stimulation improves low back pain during pregnancy.

    Science.gov (United States)

    Keskin, E A; Onur, O; Keskin, H L; Gumus, I I; Kafali, H; Turhan, N

    2012-01-01

    To compare the efficiency of transcutaneous electrical nerve stimulation (TENS) with those of exercise and acetaminophen for the treatment of pregnancy-related low back pain (LBP) during the third trimester of pregnancy. This prospective study included 79 subjects (≥32 gestational weeks) with visual analog scale (VAS) pain scores ≥5. Participants were divided randomly into a control group (n = 21) and three treatment groups [exercise (n = 19); acetaminophen (n = 19); TENS (n = 20)]. The VAS and the Roland-Morris disability questionnaire (RMDQ) were completed before and 3 weeks after treatment to assess the impact of pain on daily activities. During the study period, pain intensity increased in 57% of participants in the control group, whereas pain decreased in 95% of participants in the exercise group and in all participants in the acetaminophen and TENS groups. Post-treatment VAS and RMDQ values were significantly lower in the treatment groups (p pain relief in the TENS group than in the exercise and acetaminophen groups (p TENS application on pregnant women was observed during the study. TENS is an effective and safe treatment modality for LBP during pregnancy. TENS improved LBP more effectively than did exercise and acetaminophen. Copyright © 2012 S. Karger AG, Basel.

  12. Utility of noninvasive transcutaneous measurement of postoperative hemoglobin in total joint arthroplasty patients.

    Science.gov (United States)

    Stoesz, Michael; Wood, Kristin; Clark, Wesley; Kwon, Young-Min; Freiberg, Andrew A

    2014-11-01

    This study prospectively evaluated the clinical utility of a noninvasive transcutaneous device for postoperative hemoglobin measurement in 100 total hip and knee arthroplasty patients. A protocol to measure hemoglobin noninvasively, prior to venipuncture, successfully avoided venipuncture in 73% of patients. In the remaining 27 patients, there were a total of 48 venipunctures performed during the postoperative hospitalization period due to reasons including transcutaneous hemoglobin measurement less than or equal to 9 g/dL (19), inability to obtain a transcutaneous hemoglobin measurement (8), clinical signs of anemia (3), and noncompliance with the study protocol (18). Such screening protocols may provide a convenient and cost-effective alternative to routine venipuncture for identifying patients at risk for blood transfusion after elective joint arthroplasty. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Oxygen dependency of porfiromycin cytotoxicity

    International Nuclear Information System (INIS)

    Marshall, R.S.; Rauth, A.M.

    1987-01-01

    The authors determined the oxygen dependency of toxicity for the bioreductive alkylating agents mitomycin C (MMC) and porfiromycin (PM) to investigate whether the toxicities of these agents increase in the range of oxygen tensions over which cells become increasingly radioresistant. In the present work the oxygen dependency of PM in CHO cells was determined by assaying survival as a function of time of exposure to 1.0 μg/ml PM under various known levels of oxygen. While PM demonstrated preferential hypoxic cell toxicity, aerobic cell survival was reduced ten-fold after five hours of exposure. Conversely, PM toxicity after a five hour hypoxic exposure to <0.001% oxygen appeared to be greater than that observed for similar MMC exposures, suggesting that PM may be more selective than MMC in killing hypoxic rather than aerobic cells. The authors are currently investigating this preferential toxicity in two human cell lines, one of which is resistant to these agents. At present, these observations suggest that PM may be more effective than MMC at destroying tumour cells in regions of intermediate and low oxygen tensions which may survive radiotherapy, though the range of oxygen tensions which mediate toxicity is similar for both agents

  14. The effect of transcutaneous application of carbon dioxide (CO2) on skeletal muscle

    International Nuclear Information System (INIS)

    Oe, Keisuke; Ueha, Takeshi; Sakai, Yoshitada; Niikura, Takahiro; Lee, Sang Yang; Koh, Akihiro; Hasegawa, Takumi; Tanaka, Masaya; Miwa, Masahiko; Kurosaka, Masahiro

    2011-01-01

    Highlights: → PGC-1α is up-regulated as a result of exercise such as mitochondrial biogenesis and muscle fiber-type switching, and up-regulation of VEGF. → We demonstrated transcutaneous application of CO 2 up-regulated the gene expression of PGC-1α, SIRT1 and VEGF, and instance of muscle fiber switching. → Transcutaneous application of CO 2 may cause similar effect to aerobic exercise in skeletal muscle. -- Abstract: In Europe, carbon dioxide therapy has been used for cardiac disease and skin problems for a long time. However there have been few reports investigating the effects of carbon dioxide therapy on skeletal muscle. Peroxisome proliferators-activated receptor (PPAR)-gamma coactivator-1 (PGC-1α) is up-regulated as a result of exercise and mediates known responses to exercise, such as mitochondrial biogenesis and muscle fiber-type switching, and neovascularization via up-regulation of vascular endothelial growth factor (VEGF). It is also known that silent mating type information regulation 2 homologs 1 (SIRT1) enhances PGC-1α-mediated muscle fiber-type switching. Previously, we demonstrated transcutaneous application of CO 2 increased blood flow and a partial increase of O 2 pressure in the local tissue known as the Bohr effect. In this study, we transcutaneously applied CO 2 to the lower limbs of rats, and investigated the effect on the fast muscle, tibialis anterior (TA) muscle. The transcutaneous CO 2 application caused: (1) the gene expression of PGC-1α, silent mating type information regulation 2 homologs 1 (SIRT1) and VEGF, and increased the number of mitochondria, as proven by real-time PCR and immunohistochemistry, (2) muscle fiber switching in the TA muscle, as proven by isolation of myosin heavy chain and ATPase staining. Our results suggest the transcutaneous application of CO 2 may have therapeutic potential for muscular strength recovery resulting from disuse atrophy in post-operative patients and the elderly population.

  15. Effects of a single dose of terlipressin on transcutaneous oxygen pressures

    DEFF Research Database (Denmark)

    Krag, Aleksander; Møller, Søren; Henriksen, Jens H

    2010-01-01

    (TcPO(2) mmHg) after administration of 2 mg of TP. Patients and methods. Nineteen patients with cirrhosis and ascites were included. TcPO(2) mmHg were measured continuously measured at the chest, abdominal wall and at the lower extremity at baseline and after 2 mg TP in 15 patients and placebo in 4...... patients. Results. The mean whole body TcPO(2) decreased after TP by 34% (p ... compared to 0% in the placebo group, p = 0.005. There were no significant changes in TcPO(2) after placebo. The baseline leg TcPO(2) correlated inversely with the MELD score (r = -0.64 and p PO(2) at the thorax (r = -0.60, p = 0...

  16. Transcutaneous transhepatic portography in the diagnosis of neoplasms of the organs of the hepatopancreatoduodenal zone

    International Nuclear Information System (INIS)

    Savel'ev, V.S.; Prokubovskij, V.I.; Kapranov, S.A.

    1987-01-01

    An analysis of the results of 135 transcutaneous transhepatic investigations of the venous system including 39 superselective investigations of the pancreatoduodenal veins conducted in 78 patients with different diseases of the organs of the hepatopancreatodoudenal zone, made it possible to describe in detail and systematize their phlebographic semiotics. The diagnostic accuracy of the transhepatic radiopaque investigation of the portal vein in pancreatic diseases was 96.5%, in tumors of the biliary tract - 89.5%. The results of transcutaneous transhepatic portography formed the basis for the determination of a size of lesion and applicability of surgery in blastomatous involvement of the organs of the hepatopancreatoduodenal zone

  17. Tension pneumocephalus: Mount Fuji sign

    Directory of Open Access Journals (Sweden)

    Pulastya Sanyal

    2015-01-01

    Full Text Available A 13-year-old male was operated for a space occupying lesion in the brain. A noncontrast computed tomography scan done in the late postoperative period showed massive subdural air collection causing compression of bilateral frontal lobes with widening of interhemispheric fissure and the frontal lobes acquiring a peak like configuration - causing tension pneumocephalus-"Mount Fuji sign." Tension pneumocephalus occurs when air enters the extradural or intradural spaces in sufficient volume to exert a mass or pressure effect on the brain, leading to brain herniation. Tension pneumocephalus is a surgical emergency, which needs immediate intervention in the form of decompression of the cranial cavity by a burr hole or needle aspiration. The Mount Fuji sign differentiates tension pneumocephalus from pneumocephalus.

  18. Solid nanoemulsion as antigen and immunopotentiator carrier for transcutaneous immunization.

    Science.gov (United States)

    Gogoll, Karsten; Stein, Pamela; Lee, K D; Arnold, Philipp; Peters, Tanja; Schild, Hansjörg; Radsak, Markus; Langguth, Peter

    2016-10-01

    Imiquimod, a toll-like receptor 7 (TLR7) agonist, is an active pharmaceutical ingredient (API) established for the topical treatment of several dermal cancerous and precancerous skin lesions. Within this work, the immunostimulatory effect of imiquimod is further exploited in a transcutaneous immunization (TCI) approach based on a solid nanoemulsion (SN) formulation. SN contains a combination of imiquimod with the model peptide antigen SIINFEKL as a novel approach to omit needle and syringe and optimize dermal antigen administration. Excipients including sucrose fatty acid esters and the pharmaceutically acceptable oils MCT (middle chain triglycerides), avocado oil, jojoba wax and squalene are high pressure homogenized together with the antigen SIINFEKL. Freeze drying was performed to eliminate water and to achieve spreadable properties of the formulation for dermal administration. The influence of the different oil components was assessed regarding in vitro drug permeation in a Franz diffusion cell model using a murine skin setup. In vivo performance in terms of cytotoxic T-cell response was assessed in a C57BL/6 mouse model. Whereas Aldara® cream contains imiquimod in a dissolved state, the SN formulations carry the active in a suspended state. This resulted in a reduction of imiquimod permeation across murine skin from the SN when compared to Aldara® cream. In spite of this permeation rate reduction, each SN induced an in vivo immune response by specific T-cell lysis. A stabilized solid nanosuspension containing squalene/tocopherol exhibited a significantly higher performance (p⩽0.05) in comparison with Aldara® cream. MCT based SN exerted an in vivo effect comparable to Aldara®. In conclusion, anhydrous highly dispersed vehicles containing imiquimod in a submicron particle size distribution can represent promising formulations for TCI. The choice of the oil component has a strong influence on SN performance, independent of in vitro drug permeation

  19. Perceptual embodiment of prosthetic limbs by transcutaneous electrical nerve stimulation.

    Science.gov (United States)

    Mulvey, Matthew R; Fawkner, Helen J; Radford, Helen E; Johnson, Mark I

    2012-01-01

      In able-bodied participants, it is possible to induce a sense of perceptual embodiment in an artificial hand using a visual-tactile illusion. In amputee patients, electrical stimulation of sensory afferents using transcutaneous electrical nerve stimulation (TENS) has been shown to generate somatic sensations in an amputee's phantom limb(s). However, the effects of TENS on the perceptual embodiment of an artificial limb are not known. Our objective was to investigate the effects of TENS on the perceptual embodiment of an artificial limb in fully intact able-bodied participants.   We used a modified version of the rubber hand illusion presented to 30 able-bodied participants (16 women, 14 men) to convey TENS paresthesia to an artificial hand. TENS electrodes were located over superficial radial nerve on the lateral aspect of the right forearm (1 cm proximal to the wrist), which was hidden from view. TENS intensity was increased to a strong non-painful TENS sensation (electrical paresthesia) was felt beneath the electrodes and projecting into the fingers of the hand. The electrical characteristics of TENS were asymmetric biphasic electrical pulsed waves, continuous pulse pattern, 120 Hz pulse frequency (rate), and 80 µs pulse duration (width).   Participants reported significantly higher intensities of the rubber hand illusion during the two TENS conditions (mean = 5.8, standard deviation = 1.9) compared with the two non-TENS conditions (mean = 4.9, standard deviation = 1.7), p embodiment of an artificial hand. Further exploratory studies involving an amputee population are warranted. © 2011 International Neuromodulation Society.

  20. Transcutaneous electrical nerve stimulation (TENS) for neuropathic pain in adults.

    Science.gov (United States)

    Gibson, William; Wand, Benedict M; O'Connell, Neil E

    2017-09-14

    Neuropathic pain, which is due to nerve disease or damage, represents a significant burden on people and society. It can be particularly unpleasant and achieving adequate symptom control can be difficult. Non-pharmacological methods of treatment are often employed by people with neuropathic pain and may include transcutaneous electrical nerve stimulation (TENS). This review supersedes one Cochrane Review 'Transcutaneous electrical nerve stimulation (TENS) for chronic pain' (Nnoaham 2014) and one withdrawn protocol 'Transcutaneous electrical nerve stimulation (TENS) for neuropathic pain in adults' (Claydon 2014). This review replaces the original protocol for neuropathic pain that was withdrawn. To determine the analgesic effectiveness of TENS versus placebo (sham) TENS, TENS versus usual care, TENS versus no treatment and TENS in addition to usual care versus usual care alone in the management of neuropathic pain in adults. We searched CENTRAL, MEDLINE, Embase, PsycINFO, AMED, CINAHL, Web of Science, PEDro, LILACS (up to September 2016) and various clinical trials registries. We also searched bibliographies of included studies for further relevant studies. We included randomised controlled trials where TENS was evaluated in the treatment of central or peripheral neuropathic pain. We included studies if they investigated the following: TENS versus placebo (sham) TENS, TENS versus usual care, TENS versus no treatment and TENS in addition to usual care versus usual care alone in the management of neuropathic pain in adults. Two review authors independently screened all database search results and identified papers requiring full-text assessment. Subsequently, two review authors independently applied inclusion/exclusion criteria to these studies. The same review authors then independently extracted data, assessed for risk of bias using the Cochrane standard tool and rated the quality of evidence using GRADE. We included 15 studies with 724 participants. We found a

  1. Polydeoxyribonucleotide Improves Peripheral Tissue Oxygenation and Accelerates Angiogenesis in Diabetic Foot Ulcers

    Directory of Open Access Journals (Sweden)

    Seoyoung Kim

    2017-11-01

    Full Text Available Background Polydeoxyribonucleotide (PDRN is known to have anti-inflammatory and angiogenic effects and to accelerate wound healing. The aim of this study was to investigate whether PDRN could improve peripheral tissue oxygenation and angiogenesis in diabetic foot ulcers. Methods This was a prospective randomized controlled clinical trial. Twenty patients with a non-healing diabetic foot ulcer were randomly distributed into a control group (n=10 and a PDRN group (n=10. Initial surgical debridement and secondary surgical procedures such as a split-thickness skin graft, primary closure, or local flap were performed. Between the initial surgical debridement and secondary surgical procedures, 0.9% normal saline (3 mL or PDRN was injected for 2 weeks by the intramuscular (1 ampule, 3 mL, 5.625 mg, 5 days per week and perilesional routes (1 ampule, 3 mL, 5.625 mg, 2 days per week. Transcutaneous oxygen tension (TcPO2 was evaluated using the Periflux System 5000 with TcPO2/CO2 unit 5040 before the injections and on days 1, 3, 7, 14, and 28 after the start of the injections. A pathologic review (hematoxylin and eosin stain of the debrided specimens was conducted by a pathologist, and vessel density (average number of vessels per visual field was calculated. Results Compared with the control group, the PDRN-treated group showed improvements in peripheral tissue oxygenation on day 7 (P<0.01, day 14 (P<0.001, and day 28 (P<0.001. The pathologic review of the specimens from the PDRN group showed increased angiogenesis and improved inflammation compared with the control group. No statistically significant difference was found between the control group and the PDRN group in terms of vessel density (P=0.094. Complete healing was achieved in every patient. Conclusions In this study, PDRN improved peripheral tissue oxygenation. Moreover, PDRN is thought to be effective in improving inflammation and angiogenesis in diabetic foot ulcers.

  2. Transcutaneous carbon dioxide enhances the antitumor effect of radiotherapy on oral squamous cell carcinoma.

    Science.gov (United States)

    Iwata, Eiji; Hasegawa, Takumi; Ueha, Takeshi; Takeda, Daisuke; Saito, Izumi; Kawamoto, Teruya; Akisue, Toshihiro; Sakai, Yoshitada; Sasaki, Ryohei; Kuroda, Ryosuke; Komori, Takahide

    2018-05-16

    Radiotherapy (RT) is one of the main treatment modalities for oral squamous cell carcinoma (OSCC), however, radioresistance is a major impediment to its clinical success and poses as a concern that needs to be addressed. Tumor hypoxia is known to be significantly associated with radioresistance in various malignancies, hence, resolving the hypoxic state of a tumor may improve the antitumor effect of RT on OSCC. We have previously revealed that transcutaneous CO2 induced mitochondrial apoptosis and suppressed tumor growth in OSCC by resolving hypoxia. Considering the previous study, we hypothesized that transcutaneous CO2 may enhance the antitumor effect of RT on OSCC by improving intratumoral hypoxia, thereby overcoming radioresistance. In the present study, the combination of transcutaneous CO2 and RT significantly inhibited tumor growth compared with other treatments. This combination therapy also led to decreased expression of HIF-1α in parallel with increased expression of the cleaved forms of caspase-3-8-9 and PARP, which play essential roles in mitochondrial apoptosis. Additionally, the combination therapy increased the expression of ROS modulator 1 and subsequent mitochondrial ROS production, compared to RT alone. These results indicated that transcutaneous CO2 could potentially improve the antitumor effect of RT by decreasing the intratumoral hypoxia and increasing the mitochondrial apoptosis. Our findings indicated that CO2 therapy may be a novel adjuvant therapy in combination with RT for OSCC.

  3. 42 CFR 414.232 - Special payment rules for transcutaneous electrical nerve stimulators (TENS).

    Science.gov (United States)

    2010-10-01

    ... nerve stimulators (TENS). 414.232 Section 414.232 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... Special payment rules for transcutaneous electrical nerve stimulators (TENS). (a) General payment rule. Except as provided in paragraph (b) of this section, payment for TENS is made on a purchase basis with...

  4. Effects of transcutaneous electrical nerve stimulation (TENS) on memory in elderly with mild cognitive impairment.

    NARCIS (Netherlands)

    Luijpen, M.W.; Swaab, D.F.; Sergeant, J.A.; Dijk, K.R.A.; Scherder, E.J.

    2005-01-01

    In previous studies, transcutaneous electrical nerve stimulation (TENS) was shown to have a positive effect on memory in Alzheimer's disease (AD) patients. Moreover, the reported effects appeared to be more beneficial in early stages of Alzheimer's disease compared to later stage intervention. Based

  5. Effects of transcutaneous electrical nerve stimulation (TENS) on memory in elderly with mild cognitive impairment

    NARCIS (Netherlands)

    Luijpen, MW; Swaab, DF; Sergeant, JA; van Dijk, KRA; Scherder, EJA

    2005-01-01

    In previous studies, transcutaneous electrical nerve stimulation (TENS) was shown to have a positive effect on memory in Alzheimer's disease (AD) patients. Moreover, the reported effects appeared to be more beneficial in early stages of Alzheimer's disease compared to later stage intervention. Based

  6. Effects of transcutaneous electrical nerve stimulation (TENS) on cognition and behaviour in aging

    NARCIS (Netherlands)

    Scherder, E.J A; van Someren, E.W J; Bouma, J.M.; van der Berg, M

    2000-01-01

    In previous studies, transcutaneous electrical nerve stimulation (TENS) improved cognition and behaviour in patients with Alzheimer's disease (AD). The rationale underlying these studies was that TENS could activate, e.g. the septo-hippocampal region and the hypothalamus through direct and indirect

  7. Transcutaneous electrical nerve stimulation (TENS) improves the rest-activity rhythm in midstage Alzheimer's disease

    NARCIS (Netherlands)

    Scherder, E. J.; van Someren, E. J.; Swaab, D. F.

    1999-01-01

    Nightly restlessness in patients with Alzheimer's disease (AD) is probably due to a disorder of circadian rhythms. Transcutaneous electrical nerve stimulation (TENS) was previously reported to increase the strength of coupling of the circadian rest activity rhythm to Zeitgebers in early stage

  8. Transcutaneous migration of foreign body into thorax in children: A report of two cases

    Directory of Open Access Journals (Sweden)

    Bothra Jyoti

    2016-11-01

    Full Text Available Inhalation and ingestion of foreign bodies is common in pediatric age group. However transcutaneous migration of sharps into the lung parenchyma is rarely reported and can be hazardous. We report two such cases with details on the diagnosis and the treatment modalities used for the management.

  9. Microneedle arrays for the transcutaneous immunization of diphtheria and influenza in BALB/c mice

    NARCIS (Netherlands)

    Ding, Z.; Verbaan, F. J.; Bivas-Benita, M.; Bungener, L.; Huckriede, A.; van den Berg, D. J.; Kersten, G.; Bouwstra, J. A.

    2009-01-01

    Transcutaneous immunization (TCI) is limited by poor permeation of macromolecules across the skin. Microneedle arrays form transient conduits and enhance the transport of vaccine molecules across the skin barrier without pain sensation. Here we investigated in mouse the immune responses after TO

  10. Effects of Transcutaneous Electrical Nerve Stimulation (TENS) on cognition and behaviour in aging

    NARCIS (Netherlands)

    Scherder, E.J.A.; Bouma, A.; van den Berg, M.

    2000-01-01

    In previous studies, transcutaneous electrical nerve stimulation (TENS) improved cognition and behaviour in patients with Alzheimer's disease (AD). The rationale underlying these studies was that TENS could activate, e.g. the septo-hippocampal region and the hypothalamus through direct and indirect

  11. The influence of stellate ganglion transcutaneous electrical nerve stimulation on signal quality of pulse oximetry in prehospital trauma care.

    Science.gov (United States)

    Barker, Renate; Lang, Thomas; Hager, Helmut; Steinlechner, Barbara; Hoerauf, Klaus; Zimpfer, Michael; Kober, Alexander

    2007-05-01

    Accurate monitoring of the peripheral arterial oxygen saturation has become an important tool in the prehospital emergency medicine. This monitoring requires an adequate plethysmographic pulsation. Signal quality is diminished by cold ambient temperature due to vasoconstriction. Blockade of the stellate ganglion can improve peripheral vascular perfusion and can be achieved by direct injection or transcutaneous electrical nerve stimulation (TENS) stimulation. We evaluated whether TENS on the stellate ganglion would reduce vasoconstriction and thereby improve signal detection quality of peripheral pulse oximetry. In our study, 53 patients with minor trauma who required transport to the hospital were enrolled. We recorded vital signs, including core and skin temperature before and after transport to the hospital. Pulse oximetry sensors were attached to the patient's second finger on both hands. TENS of the stellate ganglion was started on one side after the beginning of the transport. Pulse oximeter alerts, due to poor signal detection, were recorded for each side separately. On the hand treated with TENS we detected a significant reduction of alerts compared to the other side (mean alerts TENS 3.1 [1-15] versus control side 8.8 [1-28] P signal quality of pulse oximeters in the prehospital setting.

  12. Intraoperative transfusion threshold and tissue oxygenation

    DEFF Research Database (Denmark)

    Nielsen, K; Dahl, B; Johansson, P I

    2012-01-01

    Transfusion with allogeneic red blood cells (RBCs) may be needed to maintain oxygen delivery during major surgery, but the appropriate haemoglobin (Hb) concentration threshold has not been well established. We hypothesised that a higher level of Hb would be associated with improved subcutaneous...... oxygen tension during major spinal surgery....

  13. Optimal clinical time for reliable measurement of transcutaneous CO2 with ear probes: counterbalancing overshoot and the vasodilatation effect.

    Science.gov (United States)

    Domingo, Christian; Canturri, Elisa; Moreno, Amalia; Espuelas, Humildad; Vigil, Laura; Luján, Manel

    2010-01-01

    To determine the optimal clinical reading time for the transcutaneous measurement of oxygen saturation (SpO(2)) and transcutaneous CO(2) (TcPCO(2)) in awake spontaneously breathing individuals, considering the overshoot phenomenon (transient overestimation of arterial PaCO(2)). EXPERIMENTAL SECTION: Observational study of 91 (75 men) individuals undergoing forced spirometry, measurement of SpO(2) and TcPCO(2) with the SenTec monitor every two minutes until minute 20 and arterial blood gas (ABG) analysis. Overshoot severity: (a) mild (0.1-1.9 mm Hg); (b) moderate (2-4.9 mm Hg); (c) severe: (>5 mm Hg). The mean difference was calculated for SpO(2) and TcPCO(2) and arterial values of PaCO(2) and SpO(2). The intraclass correlation coefficient (ICC) between monitor readings and blood values was calculated as a measure of agreement. The mean age was 63.1 ± 11.8 years. Spirometric values: FVC: 75.4 ± 6.2%; FEV(1): 72.9 ± 23.9%; FEV(1)/FVC: 70 ± 15.5%. ABG: PaO(2): 82.6 ± 13.2; PaCO(2): 39.9.1 ± 4.8 mmHg; SaO(2): 95.3 ± 4.4%. Overshoot analysis: overshoot was mild in 33 (36.3%) patients, moderate in 20 (22%) and severe in nine (10%); no overshoot was observed in 29 (31%) patients. The lowest mean differences between arterial blood gas and TcPCO(2) was -0.57 mmHg at minute 10, although the highest ICC was obtained at minutes 12 and 14 (>0.8). The overshoot lost its influence after minute 12. For SpO(2), measurements were reliable at minute 2. The optimal clinical reading measurement recommended for the ear lobe TcPCO(2) measurement ranges between minute 12 and 14. The SpO(2) measurement can be performed at minute 2.

  14. Optimal Clinical Time for Reliable Measurement of Transcutaneous CO2 with Ear Probes: Counterbalancing Overshoot and the Vasodilatation Effect

    Directory of Open Access Journals (Sweden)

    Manel Luján

    2010-01-01

    Full Text Available OBJECTIVES: To determine the optimal clinical reading time for the transcutaneous measurement of oxygen saturation (SpO and transcutaneous CO2 (TcPCO2 in awake spontaneously breathing individuals, considering the overshoot phenomenon (transient overestimation of arterial PaCO2. EXPERIMENTAL SECTION: Observational study of 91 (75 men individuals undergoing forced spirometry, measurement of SpO2 and TcPCO2 with the SenTec monitor every two minutes until minute 20 and arterial blood gas (ABG analysis. Overshoot severity: (a mild (0.1–1.9 mm Hg; (b moderate (2–4.9 mm Hg; (c severe: (>5 mm Hg. The mean difference was calculated for SpO2 and TcPCO2 and arterial values of PaCO2 and SpO2. The intraclass correlation coefficient (ICC between monitor readings and blood values was calculated as a measure of agreement. RESULTS: The mean age was 63.1 ± 11.8 years. Spirometric values: FVC: 75.4 ± 6.2%; FEV1: 72.9 ± 23.9%; FEV1/FVC: 70 ± 15.5%. ABG: PaO2: 82.6 ± 13.2; PaCO2: 39.9.1 ± 4.8 mmHg; SaO2: 95.3 ± 4.4%. Overshoot analysis: overshoot was mild in 33 (36.3% patients, moderate in 20 (22% and severe in nine (10%; no overshoot was observed in 29 (31% patients. The lowest mean differences between arterial blood gas and TcPCO2 was –0.57 mmHg at minute 10, although the highest ICC was obtained at minutes 12 and 14 (>0.8. The overshoot lost its influence after minute 12. For SpO2, measurements were reliable at minute 2. CONCLUSIONS: The optimal clinical reading measurement recommended for the ear lobe TcPCO2 measurement ranges between minute 12 and 14. The SpO2 measurement can be performed at minute 2.

  15. Optimal Clinical Time for Reliable Measurement of Transcutaneous CO2 with Ear Probes: Counterbalancing Overshoot and the Vasodilatation Effect

    Science.gov (United States)

    Domingo, Christian; Canturri, Elisa; Moreno, Amalia; Espuelas, Humildad; Vigil, Laura; Luján, Manel

    2010-01-01

    OBJECTIVES: To determine the optimal clinical reading time for the transcutaneous measurement of oxygen saturation (SpO2) and transcutaneous CO2 (TcPCO2) in awake spontaneously breathing individuals, considering the overshoot phenomenon (transient overestimation of arterial PaCO2). EXPERIMENTAL SECTION: Observational study of 91 (75 men) individuals undergoing forced spirometry, measurement of SpO2 and TcPCO2 with the SenTec monitor every two minutes until minute 20 and arterial blood gas (ABG) analysis. Overshoot severity: (a) mild (0.1–1.9 mm Hg); (b) moderate (2–4.9 mm Hg); (c) severe: (>5 mm Hg). The mean difference was calculated for SpO2 and TcPCO2 and arterial values of PaCO2 and SpO2. The intraclass correlation coefficient (ICC) between monitor readings and blood values was calculated as a measure of agreement. RESULTS: The mean age was 63.1 ± 11.8 years. Spirometric values: FVC: 75.4 ± 6.2%; FEV1: 72.9 ± 23.9%; FEV1/FVC: 70 ± 15.5%. ABG: PaO2: 82.6 ± 13.2; PaCO2: 39.9.1 ± 4.8 mmHg; SaO2: 95.3 ± 4.4%. Overshoot analysis: overshoot was mild in 33 (36.3%) patients, moderate in 20 (22%) and severe in nine (10%); no overshoot was observed in 29 (31%) patients. The lowest mean differences between arterial blood gas and TcPCO2 was −0.57 mmHg at minute 10, although the highest ICC was obtained at minutes 12 and 14 (>0.8). The overshoot lost its influence after minute 12. For SpO2, measurements were reliable at minute 2. CONCLUSIONS: The optimal clinical reading measurement recommended for the ear lobe TcPCO2 measurement ranges between minute 12 and 14. The SpO2 measurement can be performed at minute 2. PMID:22315552

  16. Rearfoot Transcutaneous Oximetry is a Useful Tool to Highlight Ischemia of the Heel

    Energy Technology Data Exchange (ETDEWEB)

    Izzo, Valentina, E-mail: valentina-izzo@virgilio.it; Meloni, Marco, E-mail: meloni.marco@libero.it [University of Tor Vergata, Department of Systems Medicine (Italy); Fabiano, Sebastiano, E-mail: sebas575@yahoo.it; Morosetti, Daniele, E-mail: danielemorosetti@hotmail.com [University of Tor Vergata, Department of Diagnostic Imaging and Interventional Radiology (Italy); Giurato, Laura, E-mail: lauragiurato@yahoo.it [University of Tor Vergata, Department of Systems Medicine (Italy); Chiaravalloti, Antonio, E-mail: antoniochiaravalloti@hotmail.it [University of Tor Vergata, Department of Diagnostic Imaging and Interventional Radiology (Italy); Ruotolo, Valeria, E-mail: valeriaruotolo@virgilio.it [University of Tor Vergata, Department of Systems Medicine (Italy); Gandini, Roberto, E-mail: roberto.gandini@fastwebnet.it [University of Tor Vergata, Department of Diagnostic Imaging and Interventional Radiology (Italy); Uccioli, Luigi, E-mail: luccioli@yahoo.com [University of Tor Vergata, Department of Systems Medicine (Italy)

    2017-01-15

    PurposeTo demonstrate the usefulness of rearfoot transcutaneous oximetry to assess the peripheral arterial disease in diabetic patients with heel ulcer.MethodsFrom our database of 550 critical limb ischemia diabetic patients followed after a percutaneous transluminal angioplasty, we have selected patients with below the knee arterial disease. Patients were grouped according to the dorsal transcutaneous oximetry value (Group A < 30 mmHg; Group B ≥ 30 mmHg). Patients of Group B had a second oximetry performed at the rearfoot, close to the lesion localized in all cases at the heel. Finally, the analysis of the arterial pattern disease has been done.ResultsWe selected 191 patients: Group A (151 patients), dorsal transcutaneous oximetry of 11.8 ± 0.7 mmHg; Group B (40 patients), dorsal transcutaneous oximetry of 44.2 ± 10.1 mmHg. In Group B, rearfoot oximetry was 20.5 ± 5 mmHg, significantly lower than dorsal oximetry (p = 0.0179). The anterior tibial artery was involved in all patients of Group A. In Group B, the anterior tibial artery was involved in 15 subjects and never alone; the posterior tibial artery was involved in 20 subjects and in 11 cases alone. The peroneal artery was affected in 20 subjects and in 14 patients alone.ConclusionWhen a heel lesion is present and the transcutaneous oximetry recorded on the dorsum of the foot does not confirm the presence of critical limb ischemia (not ≤30 mmHg), a second oximetry recorded on the rearfoot is useful to point out ischemia of the peroneal artery and/or of the posterior tibial artery.

  17. Rearfoot Transcutaneous Oximetry is a Useful Tool to Highlight Ischemia of the Heel

    International Nuclear Information System (INIS)

    Izzo, Valentina; Meloni, Marco; Fabiano, Sebastiano; Morosetti, Daniele; Giurato, Laura; Chiaravalloti, Antonio; Ruotolo, Valeria; Gandini, Roberto; Uccioli, Luigi

    2017-01-01

    PurposeTo demonstrate the usefulness of rearfoot transcutaneous oximetry to assess the peripheral arterial disease in diabetic patients with heel ulcer.MethodsFrom our database of 550 critical limb ischemia diabetic patients followed after a percutaneous transluminal angioplasty, we have selected patients with below the knee arterial disease. Patients were grouped according to the dorsal transcutaneous oximetry value (Group A < 30 mmHg; Group B ≥ 30 mmHg). Patients of Group B had a second oximetry performed at the rearfoot, close to the lesion localized in all cases at the heel. Finally, the analysis of the arterial pattern disease has been done.ResultsWe selected 191 patients: Group A (151 patients), dorsal transcutaneous oximetry of 11.8 ± 0.7 mmHg; Group B (40 patients), dorsal transcutaneous oximetry of 44.2 ± 10.1 mmHg. In Group B, rearfoot oximetry was 20.5 ± 5 mmHg, significantly lower than dorsal oximetry (p = 0.0179). The anterior tibial artery was involved in all patients of Group A. In Group B, the anterior tibial artery was involved in 15 subjects and never alone; the posterior tibial artery was involved in 20 subjects and in 11 cases alone. The peroneal artery was affected in 20 subjects and in 14 patients alone.ConclusionWhen a heel lesion is present and the transcutaneous oximetry recorded on the dorsum of the foot does not confirm the presence of critical limb ischemia (not ≤30 mmHg), a second oximetry recorded on the rearfoot is useful to point out ischemia of the peroneal artery and/or of the posterior tibial artery.

  18. Analysis, design, and control of a transcutaneous power regulator for artificial hearts.

    Science.gov (United States)

    Qianhong Chen; Siu Chung Wong; Tse, C K; Xinbo Ruan

    2009-02-01

    Based on a generic transcutaneous transformer model, a remote power supply using a resonant topology for use in artificial hearts is analyzed and designed for easy controllability and high efficiency. The primary and secondary windings of the transcutaneous transformer are positioned outside and inside the human body, respectively. In such a transformer, the alignment and gap may change with external positioning. As a result, the coupling coefficient of the transcutaneous transformer is also varying, and so are the two large leakage inductances and the mutual inductance. Resonant-tank circuits with varying resonant-frequency are formed from the transformer inductors and external capacitors. For a given range of coupling coefficients, an operating frequency corresponding to a particular coupling coefficient can be found, for which the voltage transfer function is insensitive to load. Prior works have used frequency modulation to regulate the output voltage under varying load and transformer coupling. The use of frequency modulation may require a wide control frequency range which may extend well above the load insensitive frequency. In this paper, study of the input-to-output voltage transfer function is carried out, and a control method is proposed to lock the switching frequency at just above the load insensitive frequency for optimized efficiency at heavy loads. Specifically, operation at above resonant of the resonant circuits is maintained under varying coupling-coefficient. Using a digital-phase-lock-loop (PLL), zero-voltage switching is achieved in a full-bridge converter which is also programmed to provide output voltage regulation via pulsewidth modulation (PWM). A prototype transcutaneous power regulator is built and found to to perform excellently with high efficiency and tight regulation under variations of the alignment or gap of the transcutaneous transformer, load and input voltage.

  19. Micromachined three-dimensional electrode arrays for transcutaneous nerve tracking

    Science.gov (United States)

    Rajaraman, Swaminathan; Bragg, Julian A.; Ross, James D.; Allen, Mark G.

    2011-08-01

    We report the development of metal transfer micromolded (MTM) three-dimensional microelectrode arrays (3D MEAs) for a transcutaneous nerve tracking application. The measurements of electrode-skin-electrode impedance (ESEI), electromyography (EMG) and nerve conduction utilizing these minimally invasive 3D MEAs are demonstrated in this paper. The 3D MEAs used in these measurements consist of a metalized micro-tower array that can penetrate the outer layers of the skin in a painless fashion and are fabricated using MTM technology. Two techniques, an inclined UV lithography approach and a double-side exposure of thick negative tone resist, have been developed to fabricate the 3D MEA master structure. The MEAs themselves are fabricated from the master structure utilizing micromolding techniques. Metal patterns are transferred during the micromolding process, thereby ensuring reduced process steps compared to traditional silicon-based approaches. These 3D MEAs have been packaged utilizing biocompatible Kapton® substrates. ESEI measurements have been carried out on test human subjects with standard commercial wet electrodes as a reference. The 3D MEAs demonstrate an order of magnitude lower ESEI (normalized to area) compared to wet electrodes for an area that is 12.56 times smaller. This compares well with other demonstrated approaches in literature. For a nerve tracking demonstration, we have chosen EMG and nerve conduction measurements on test human subjects. The 3D MEAs show 100% improvement in signal power and SNR/√area as compared to standard electrodes. They also demonstrate larger amplitude signals and faster rise times during nerve conduction measurements. We believe that this microfabrication and packaging approach scales well to large-area, high-density arrays required for applications like nerve tracking. This development will increase the stimulation and recording fidelity of skin surface electrodes, while increasing their spatial resolution by an order of

  20. Micromachined three-dimensional electrode arrays for transcutaneous nerve tracking

    International Nuclear Information System (INIS)

    Rajaraman, Swaminathan; Allen, Mark G; Bragg, Julian A; Ross, James D

    2011-01-01

    We report the development of metal transfer micromolded (MTM) three-dimensional microelectrode arrays (3D MEAs) for a transcutaneous nerve tracking application. The measurements of electrode–skin–electrode impedance (ESEI), electromyography (EMG) and nerve conduction utilizing these minimally invasive 3D MEAs are demonstrated in this paper. The 3D MEAs used in these measurements consist of a metalized micro-tower array that can penetrate the outer layers of the skin in a painless fashion and are fabricated using MTM technology. Two techniques, an inclined UV lithography approach and a double-side exposure of thick negative tone resist, have been developed to fabricate the 3D MEA master structure. The MEAs themselves are fabricated from the master structure utilizing micromolding techniques. Metal patterns are transferred during the micromolding process, thereby ensuring reduced process steps compared to traditional silicon-based approaches. These 3D MEAs have been packaged utilizing biocompatible Kapton® substrates. ESEI measurements have been carried out on test human subjects with standard commercial wet electrodes as a reference. The 3D MEAs demonstrate an order of magnitude lower ESEI (normalized to area) compared to wet electrodes for an area that is 12.56 times smaller. This compares well with other demonstrated approaches in literature. For a nerve tracking demonstration, we have chosen EMG and nerve conduction measurements on test human subjects. The 3D MEAs show 100% improvement in signal power and SNR/√area as compared to standard electrodes. They also demonstrate larger amplitude signals and faster rise times during nerve conduction measurements. We believe that this microfabrication and packaging approach scales well to large-area, high-density arrays required for applications like nerve tracking. This development will increase the stimulation and recording fidelity of skin surface electrodes, while increasing their spatial resolution by an order

  1. Transcutaneous electrical nerve stimulation (TENS) for pain management in labour

    Science.gov (United States)

    Dowswell, Therese; Bedwell, Carol; Lavender, Tina; Neilson, James P

    2014-01-01

    Background Transcutaneous nerve stimulation (TENS) has been proposed as a means of reducing pain in labour. The TENS unit emits low-voltage electrical impulses which vary in frequency and intensity. During labour, TENS electrodes are generally placed on the lower back, although TENS may be used to stimulate acupuncture points or other parts of the body. The physiological mechanisms whereby TENS relieves pain are uncertain. TENS machines are frequently operated by women, which may increase a sense of control in labour. Objectives To assess the effects of TENS on pain in labour. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (30 April 2011) and reference lists of retrieved papers. Selection criteria Randomised controlled trials comparing women receiving TENS for pain management in labour versus routine care, alternative non-pharmacological methods of pain relief, or placebo devices. We included all types of TENS machines. Data collection and analysis Two review authors assessed for inclusion all trials identified by the search strategy, carried out data extraction and assessed risk of bias. We have recorded reasons for excluding studies. Main results Seventeen trials with 1466 women contribute data to the review. Thirteen examined TENS applied to the back, two to acupuncture points, and two to the cranium. Overall, there was little difference in pain ratings between TENS and control groups, although women receiving TENS to acupuncture points were less likely to report severe pain (average risk ratio 0.41, 95% confidence interval 0.31 to 0.54; measured in two studies). The majority of women using TENS said they would be willing to use it again in a future labour. Where TENS was used as an adjunct to epidural analgesia there was no evidence that it reduced pain. There was no consistent evidence that TENS had any impact on interventions and outcomes in labour. There was little information on outcomes for mothers and babies. No

  2. Transcutaneous electrical nerve stimulation (TENS) for chronic low back pain.

    Science.gov (United States)

    Milne, S; Welch, V; Brosseau, L; Saginur, M; Shea, B; Tugwell, P; Wells, G

    2001-01-01

    Low back pain (LBP) affects a large proportion of the population. Transcutaneous electrical nerve stimulation (TENS) was introduced more than 30 years ago as an alternative therapy to pharmacological treatments for chronic pain. However, despite its widespread use, the effectiveness of TENS is still controversial. The aim of this systematic review was to determine the efficacy of TENS in the treatment of chronic LBP. We searched MEDLINE, EMBASE, PEDro and the Cochrane Controlled Trials Register up to June 1, 2000. Only randomized controlled clinical trials of TENS for the treatment of patients with a clinical diagnosis of chronic LBP were included. Abstracts were excluded unless further data could be obtained from the authors. Two reviewers independently selected trials and extracted data using predetermined forms. Heterogeneity was tested with Cochran's Q test. A fixed effects model was used throughout for continuous variables, except where heterogeneity existed, in which case, a random effects model was used. Results are presented as weighted mean differences (WMD) with 95% confidence intervals (95% CI), where the difference between the treated and control groups was weighted by the inverse of the variance. Standardized mean differences (SMD) were calculated by dividing the difference between the treated and control by the baseline variance. SMD were used when different scales were used to measure the same concept. Dichotomous outcomes were analyzed with odds ratios. Five trials were included, with 170 subjects randomized to the placebo group receiving sham-TENS and 251 subjects receiving active TENS (153 for conventional mode, 98 for acupuncture-like TENS). The schedule of treatments varied greatly between studies ranging from one treatment/day for two consecutive days, to three treatments/day for four weeks. There were no statistically significant differences between the active TENS group when compared to the placebo TENS group for any outcome measures

  3. Transcutaneous electrical nerve stimulation (TENS) for pain relief in labour.

    Science.gov (United States)

    Dowswell, Therese; Bedwell, Carol; Lavender, Tina; Neilson, James P

    2009-04-15

    Transcutaneous nerve stimulation (TENS) has been proposed as a means of reducing pain in labour. The TENS unit emits low-voltage electrical impulses which vary in frequency and intensity. During labour, TENS electrodes are generally placed on the lower back, although TENS may be used to stimulate acupuncture points or other parts of the body. The physiological mechanisms whereby TENS relieves pain are uncertain. The TENS unit is frequently operated by women, which may increase sense of control in labour. To assess the effects of TENS on pain in labour. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (November 2008). Randomised controlled trials comparing women receiving TENS for pain relief in labour versus routine care, alternative pharmacological methods of pain relief, or placebo devices. We included all types of TENS machines. Two review authors assessed for inclusion all trials identified by the search strategy, carried out data extraction and assessed risk of bias. We have recorded reasons for excluding studies. The search identified 25 studies; we excluded six and included 19 studies including 1671 women. Fifteen examined TENS applied to the back, two to acupuncture points and two to the cranium. Overall, there was little difference in pain ratings between TENS and control groups, although women receiving TENS to acupuncture points were less likely to report severe pain (risk ratio 0.41, 95% confidence interval 0.32 to 0.55). The majority of women using TENS said they would be willing to use it again in a future labour. Where TENS was used as an adjunct to epidural analgesia there was no evidence that it reduced pain. There was no consistent evidence that TENS had any impact on interventions and outcomes in labour. There was little information on outcomes for mothers and babies. No adverse events were reported. There is only limited evidence that TENS reduces pain in labour and it does not seem to have any impact (either positive or

  4. Magnetic tension and gravitational collapse

    International Nuclear Information System (INIS)

    Tsagas, Christos G

    2006-01-01

    The gravitational collapse of a magnetized medium is investigated by studying qualitatively the convergence of a timelike family of non-geodesic worldlines in the presence of a magnetic field. Focusing on the field's tension, we illustrate how the winding of the magnetic forcelines due to the fluid's rotation assists the collapse, while shear-like distortions in the distribution of the field's gradients resist contraction. We also show that the relativistic coupling between magnetism and geometry, together with the tension properties of the field, lead to a magneto-curvature stress that opposes the collapse. This tension stress grows stronger with increasing curvature distortion, which means that it could potentially dominate over the gravitational pull of the matter. If this happens, a converging family of non-geodesic worldlines can be prevented from focusing without violating the standard energy conditions

  5. Hyperbaric oxygen and radiotherapy

    International Nuclear Information System (INIS)

    Mayer, R.; Hamilton-Farrell, M.R.; Kleij, A.J. van der

    2005-01-01

    Background: Hyperbaric oxygen (HBO) therapy is the inhalation of 100% oxygen at a pressure of at least 1.5 atmospheres absolute (150 kPa). It uses oxygen as a drug by dissolving it in the plasma and delivering it to the tissues independent of hemoglobin. For a variety of organ systems, HBO is known to promote new vessel growth into areas with reduced oxygen tension due to poor vascularity, and therewith promotes wound healing and recovery of radiation-injured tissue. Furthermore, tumors may be sensitized to irradiation by raising intratumoral oxygen tensions. Methods: A network of hyperbaric facilities exists in Europe, and a number of clinical studies are ongoing. The intergovernmental framework COST B14 action 'Hyperbaric Oxygen Therapy' started in 1999. The main goal of the Working Group Oncology is preparation and actual implementation of prospective study protocols in the field of HBO and radiation oncology in Europe. Results: In this paper a short overview on HBO is given and the following randomized clinical studies are presented: (a) reirradiation of recurrent squamous cell carcinoma of the head and neck after HBO sensitization; (b) role of HBO in enhancing radiosensitivity on glioblastoma multiforme; (c) osseointegration in irradiated patients; adjunctive HBO to prevent implant failures; (d) the role of HBO in the treatment of late irradiation sequelae in the pelvic region. The two radiosensitization protocols (a, b) allow a time interval between HBO and subsequent irradiation of 10-20 min. Conclusion: Recruitment of centers and patients is being strongly encouraged, detailed information is given on www.oxynet.org. (orig.)

  6. Electrodes for high-definition transcutaneous DC stimulation for applications in drug-delivery and electrotherapy, including tDCS

    OpenAIRE

    Minhas, Preet; Bansal, Varun; Patel, Jinal; Ho, Johnson S.; Diaz, Julian; Datta, Abhishek; Bikson, Marom

    2010-01-01

    Transcutaneous electrical stimulation is applied in a range of biomedical applications including Transcranial Direct Current Stimulation (tDCS). tDCS is a non-invasive procedure where a weak direct current (

  7. Modulation of cerebral blood flow with transcutaneous electrical neurostimulation (TENS) in patients with cerebral vasospasm after subarachnoid hemorrhage

    NARCIS (Netherlands)

    ter Laan, Mark; van Dijk, J.M.C.; Stewart, Roy; Staal, Michiel J; Elting, Jan-Willem J.

    ObjectivesTranscutaneous electrical neurostimulation (TENS) and spinal cord stimulation have been shown to increase peripheral and cerebral blood flow. We postulate that certain pathological conditions attenuate cerebral autoregulation, which may result in a relative increase of the importance of

  8. Modulation of cerebral blood flow with transcutaneous electrical neurostimulation (TENS) in patients with cerebral vasospasm after subarachnoid hemorrhage

    NARCIS (Netherlands)

    Laan, M. ter; Dijk, J.M. van; Stewart, R.; Staal, M.J.; Elting, J.W.

    2014-01-01

    OBJECTIVES: Transcutaneous electrical neurostimulation (TENS) and spinal cord stimulation have been shown to increase peripheral and cerebral blood flow. We postulate that certain pathological conditions attenuate cerebral autoregulation, which may result in a relative increase of the importance of

  9. AUTOGENIC THERAPY IN TENSION HEADACHE

    Science.gov (United States)

    Amruthraj, Brunda; Mishra, H.; Kumaraiah, V.

    1987-01-01

    SUMMARY Ten subjects diagnosed as Psychalgia were taken for study. A multiple baseline design was adapted and clients were subjected to 30 sessions of autogenic training. They were assessed using physiological (EMG and thermal change) and behavioural measures (Visual analogue scale and behavioural symptom checklist). Findings revealed autogenic therapy to be effective in reducing tension headache. PMID:21927245

  10. Tensions of Corporate Social Responsibility

    DEFF Research Database (Denmark)

    Strand, Robert

    , and formally rational tools like key performance indicators (KPIs) can be developed and employed in service of the selected substantively rational ends. I show how these KPIs can serve to highlight tensions between substantively rational ends. As such, I argue the CSR bureaucracy can create a space...

  11. AUTOGENIC THERAPY IN TENSION HEADACHE

    OpenAIRE

    Amruthraj, Brunda; Mishra, H.; Kumaraiah, V.

    1987-01-01

    SUMMARY Ten subjects diagnosed as Psychalgia were taken for study. A multiple baseline design was adapted and clients were subjected to 30 sessions of autogenic training. They were assessed using physiological (EMG and thermal change) and behavioural measures (Visual analogue scale and behavioural symptom checklist). Findings revealed autogenic therapy to be effective in reducing tension headache.

  12. Comparative study between manual therapy and TENS Burst in patients with tension-type cephalalgia

    Directory of Open Access Journals (Sweden)

    Denise Vasconcelos Fernandes

    Full Text Available Introduction Cephalgia or cephalalgia is one of the most common symptoms in the general population. Objective To compare the efficacy of physical therapy modalities, through manual therapy and the effect of Transcutaneous Nerve Stimulation (TENS for tension-type cephalalgia. Materials and methods The study was compounded by 60 subjects, but only 40 of them completed it, due to the exclusion criteria. These were divided into control group and intervention group. The control group received treatment — manual therapy. The intervention group received TENS Burst. Patients underwent ten sessions of treatment, made at every two days on a week, lasting 30 minutes each session. Results The characteristics related to lifestyle, postural issues and range of motion are responsible for the main causes of tension-type cephalalgia. Discussion treatments showed effective results in all cases in relation to pain intensity, but the use of manual therapy techniques give the patient a better quality of life compared to the use of TENS. Final considerations The treatment of this condition deserves analysis and studies; however, there are only a few studying physical therapy techniques, especially regarding to the use of TENS.

  13. [Case of tension pneumothorax associated with asthma attack during general anesthesia].

    Science.gov (United States)

    Komasawa, Nobuyasu; Ueki, Ryusuke; Kusuyama, Kazuki; Okano, Yukari; Tatara, Tsuneo; Tashiro, Chikara

    2010-05-01

    We report a case of tension pneumothorax associated with asthma attack during general anesthesia. An 86-year-old woman with dementia underwent cataract surgery under general anesthesia. At 70 min after the start of operation, airway pressure suddenly increased from 19 to 28 cm HO2O. In spite of bag ventilation with 100% oxygen, Sp(O2) decreased to 81%. Chest-Xp showed typical image of tension pneumothorax. Chest drainage was immediately performed, after which Pa(O2) recovered soon. She was extubated on postoperative day 1 without any neurological disorder. Hyperinflation of fragile alveoli by mechanical ventilation was likely a cause of tension pneumothorax.

  14. Transcutaneous electric nerve stimulation (TENS) for cancer pain in adults.

    Science.gov (United States)

    Hurlow, Adam; Bennett, Michael I; Robb, Karen A; Johnson, Mark I; Simpson, Karen H; Oxberry, Stephen G

    2012-03-14

    Cancer-related pain is complex and multi-dimensional but the mainstay of cancer pain management has predominantly used a biomedical approach. There is a need for non-pharmacological and innovative approaches. Transcutaneous Electric Nerve Stimulation (TENS) may have a role in pain management but the effectiveness of TENS is currently unknown. This is an update of the original review published in Issue 3, 2008. The aim of this systematic review was to determine the effectiveness of TENS for cancer-related pain in adults. The initial review searched The Cochrane Library, MEDLINE, EMBASE, CINAHL, PsychINFO, AMED and PEDRO databases in April 2008. We performed an updated search of CENTRAL, MEDLINE, EMBASE, CINAHL and PEDRO databases in November 2011. We included only randomised controlled trials (RCTS) investigating the use of TENS for the management of cancer-related pain in adults. The search strategy identified a further two studies for possible inclusion. One of the review authors screened each abstract using a study eligibility tool. Where eligibility could not be determined, a second author assessed the full paper. One author used a standardised data extraction sheet to collect information on the studies and independently assess the quality of the studies using the validated five-point Oxford Quality Scale. The small sample sizes and differences in patient study populations of the three included studies (two from the original review and a third included in this update) prevented meta-analysis. For the original review the search strategy identified 37 possible published studies; we divided these between two pairs of review authors who decided on study selection; all four review authors discussed and agreed final scores. Only one additional RCT met the eligibility criteria (24 participants) for this updated review. Although this was a feasibility study, not designed to investigate intervention effect, it suggested that TENS may improve bone pain on movement in a

  15. Oxygenation measurement by multi-wavelength oxygen-dependent phosphorescence and delayed fluorescence: catchment depth and application in intact heart

    NARCIS (Netherlands)

    Balestra, Gianmarco M.; Aalders, Maurice C. G.; Specht, Patricia A. C.; Ince, Can; Mik, Egbert G.

    2015-01-01

    Oxygen delivery and metabolism represent key factors for organ function in health and disease. We describe the optical key characteristics of a technique to comprehensively measure oxygen tension (PO(2)) in myocardium, using oxygen-dependent quenching of phosphorescence and delayed fluorescence of

  16. Urinary incontinence - tension-free vaginal tape

    Science.gov (United States)

    ... ency/article/007377.htm Urinary incontinence - tension-free vaginal tape To use the sharing features on this page, please enable JavaScript. Placement of tension-free vaginal tape is surgery to help control stress urinary ...

  17. Laser Transcutaneous Bilirubin Meter: A New Device For Bilirubin Monitoring In Neonatal Jaundice

    Science.gov (United States)

    Hamza, Mostafa; Hamza, Mohammad

    1988-06-01

    Neonates with jaundice require monitoring of serum bilirubin which should be repeated at frequent intervals. However, taking blood samples from neonates is not always an easy job, plus being an invasive and traumatising procedure with the additional risk of blood loss. In this paper the authors present the theory and design of a new noninvasive device for transcutaneous bilirubinometry, using a differential absorption laser system. The new technique depends upon illuminating the skin of the neonate with radiation from a two wave-length oscillation laser. The choice of the wavelengths follows the principles of optical bilirubinometry. For obtaining more accurate measurements, different pairs of two wave-lengths are incorporated in the design. The presence of hemoglobin is corrected for by appropriate selection of the laser wavelengths. The new design was tested for accuracy and precision using an argon ion laser. Correlation study between serum bilirubin determination by laser transcutaneous bilirubinometry and by American optical bilirubinometer was highly significant.

  18. Effect of transcutaneous electrical muscle stimulation on postoperative muscle mass and protein synthesis

    DEFF Research Database (Denmark)

    Vinge, O; Edvardsen, L; Jensen, F

    1996-01-01

    In an experimental study, 13 patients undergoing major elective abdominal surgery were given postoperative transcutaneous electrical muscle stimulation (TEMS) to the quadriceps femoris muscle on one leg; the opposite leg served as control. Changes in cross-sectional area (CSA) and muscle protein ...... protein synthesis and muscle mass after abdominal surgery and should be evaluated in other catabolic states with muscle wasting.......In an experimental study, 13 patients undergoing major elective abdominal surgery were given postoperative transcutaneous electrical muscle stimulation (TEMS) to the quadriceps femoris muscle on one leg; the opposite leg served as control. Changes in cross-sectional area (CSA) and muscle protein...... synthesis were assessed by computed tomography and ribosome analysis of percutaneous muscle biopsies before surgery and on the sixth postoperative day. The percentage of polyribosomes in the ribosome suspension decreased significantly (P

  19. Transcutaneous electrical neurostimulation in musculoskeletal pain of acute spinal cord injuries.

    Science.gov (United States)

    Richardson, R R; Meyer, P R; Cerullo, L J

    1980-01-01

    Cervical, thoracic, thoracolumbar, and lumbar fractures associated with physiologic complete or incomplete spinal cord injuries frequently have severe soft-tissue injury as well as severe pain associated with the site or area of injury. Transcutaneous electrical neurostimulation has proved effective in the treatment of various causes of severe acute and chronic intractable pains. We applied this modality to a group of 20 patients who had acute spinal cord injuries and pain associated with severe, extensive soft-tissue injury. Its advantages include ease of application, lack of major complications, increased intestinal peristalsis, and avoidance of narcotic analgesic medications. It also produced significant (greater than 50%) pain relief in 75% of patients treated by transcutaneous electrical neurostimulation.

  20. Objective and subjective outcome of a new transcutaneous bone conduction hearing device

    DEFF Research Database (Denmark)

    Eberhard, Kristine Elisabeth; Olsen, Steen Østergaard; Miyazaki, Hidemi

    2016-01-01

    Objective: To examine the objective and subjective outcome of a new transcutaneous bone conduction hearing device. Study Design: Prospective, consecutive case series. Patients: Twelve patients were implanted. Eight patients had a conductive/mixed (con/mix) hearing loss. Four had single sided...... to beneficial outcome. In Speech, Spatial and Qualities of Hearing Scale 12, ''quality of hearing'' scored especially high. The con/mix hearing loss group showed larger benefit especially in SDS, SRT50% in noise and the subjective evaluations, whereas frequency and duration of use were similar. Conclusion......: This study on the first 12 Nordic patients implanted with a new transcutaneous bone conduction hearing device demonstrates significant objective, as well as subjective hearing benefit. Patient satisfaction was high, as was the frequency of use....

  1. Effectiveness of transcutaneous electrical nerve stimulation on saliva production in post-radiated oral cancer patients

    OpenAIRE

    Sakshi Ojha; Thimmarasa V Bhovi; Prashant P Jaju; Manas Gupta; Neha Singh; Kriti Shrivastava

    2016-01-01

    Aims and Objectives: To determine the effectiveness of transcutaneous electrical nerve stimulation (TENS) in stimulating salivary flow in post-radiated oral cancer patients, and to compare the salivary flow rate between unstimulated saliva and saliva stimulated with TENS in post-radiated oral cancer patients. Materials and Methods: In 30 patients who underwent radiotherapy for oral cancer, unstimulated saliva was collected every minute for 5 min in a graduated test tube. The TENS unit was act...

  2. Can the human lumbar posterior columns be stimulated by transcutaneous spinal cord stimulation? A modeling study

    OpenAIRE

    Danner, Simon M.; Hofstoetter, Ursula S.; Ladenbauer, Josef; Rattay, Frank; Minassian, Karen

    2011-01-01

    Stimulation of different spinal cord segments in humans is a widely developed clinical practice for modification of pain, altered sensation and movement. The human lumbar cord has become a target for modification of motor control by epidural and more recently by transcutaneous spinal cord stimulation. Posterior columns of the lumbar spinal cord represent a vertical system of axons and when activated can add other inputs to the motor control of the spinal cord than stimulated posterior roots. ...

  3. Transcutaneous measurement of the arterial input function in positron emission tomography

    International Nuclear Information System (INIS)

    Litton, J.E.; Eriksson, L.

    1990-01-01

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

  4. Wearable Neural Prostheses - Restoration of Sensory-Motor Function by Transcutaneous Electrical Stimulation

    OpenAIRE

    Micera, Silvestro; Keller, Thierry; Lawrence, Marc; Morari, Manfred; Popovic, Dejan B.

    2010-01-01

    In this article, we focus on the least invasive interface: transcutaneous ES (TES), i.e., the use of surface electrodes as an interface between the stimulator and sensory-motor systems. TES is delivered by a burst of short electrical charge pulses applied between pairs of electrodes positioned on the skin. Monophasic or charge-balanced biphasic (symmetric or asymmetric) stimulation pulses can be delivered. The latter ones have the advantage to provide contraction force while minimizing tissue...

  5. Wearable neural prostheses. Restoration of sensory-motor function by transcutaneous electrical stimulation.

    Science.gov (United States)

    Micera, Silvestro; Keller, Thierry; Lawrence, Marc; Morari, Manfred; Popović, Dejan B

    2010-01-01

    In this article, we focus on the least invasive interface: transcutaneous ES (TES), i.e., the use of surface electrodes as an interface between the stimulator and sensory-motor systems. TES is delivered by a burst of short electrical charge pulses applied between pairs of electrodes positioned on the skin. Monophasic or charge-balanced biphasic (symmetric or asymmetric) stimulation pulses can be delivered. The latter ones have the advantage to provide contraction force while minimizing tissue damage.

  6. Robust Tensioned Kevlar Suspension Design

    Science.gov (United States)

    Young, Joseph B.; Naylor, Bret J.; Holmes, Warren A.

    2012-01-01

    One common but challenging problem in cryogenic engineering is to produce a mount that has excellent thermal isolation but is also rigid. Such mounts can be achieved by suspending the load from a network of fibers or strings held in tension. Kevlar fibers are often used for this purpose owing to their high strength and low thermal conductivity. A suite of compact design elements has been developed to improve the reliability of suspension systems made of Kevlar.

  7. Surface Tension Confines Cryogenic Liquid

    Science.gov (United States)

    Castles, Stephen H.; Schein, Michael E.

    1989-01-01

    New type of Dewar provides passive, constant-temperature cryogenic cooling for scientific instruments under normal-to low-gravity conditions. Known as Surface-Tension-Contained Liquid Cryogen Cooler (STCLCC), keeps liquid cryogen in known location inside the Dewar by trapping liquid inside spongelike material. Unique sponge material fills most of volume of inner tank. Sponge is all-silica, open-cell material similar to that used for Space Shuttle thermal-protection tiles.

  8. Delayed Tension Pneumothorax During Surgery

    Directory of Open Access Journals (Sweden)

    Ying-Lun Chen

    2005-10-01

    Full Text Available Tension pneumothorax is a life-threatening emergency that rapidly results in cardiopulmonary arrest. It requires prompt diagnosis and treatment. We present 2 cases from our practice, 1 caused by blunt chest trauma and the other resulting from laparoscopic surgery. Both were successfully treated by insertion of a chest tube. The diagnosis and treatment of intraoperative pneumothorax is discussed together with a review of the literature.

  9. Reduced discomfort during High-Definition transcutaneous stimulation using 6% benzocaine

    Directory of Open Access Journals (Sweden)

    Berkan eGuleyupoglu

    2014-07-01

    Full Text Available AbstractBackground High-Definition transcranial Direct Current Stimulation (HD-tDCS allows for non-invasive neuromodulation using an array of compact (approximately 1 cm2 contact area High-Definition (HD electrodes, as compared to conventional tDCS (which uses two large pads that are approximately 35cm2. In a previous transcutaneous study, we developed and validated designs for HD electrodes that reduce discomfort over >20 min session with 2 mA electrode current.ObjectiveThe purpose of this study was to investigate the use of a chemical pretreatment with 6% benzocaine (topical numbing agent to further reduce subjective discomfort during transcutaneous stimulation and to allow for better sham controlled studies.MethodsPre-treatment with 6% benzocaine was compared with control (no pretreatment for 22 minutes 2 mA of stimulation, with either CCNY-4 or Lectron II electroconductive gel, for both cathodal and anodal transcutaneous (forearm stimulation (8 different combinations.Results Results show that for all conditions and polarities tested, stimulation with HD electrodes is safe and well tolerated and that pretreatment further reduced subjective discomfort. ConclusionPretreatment with a mild analgesic reduces discomfort during HD-tDCS.

  10. Adaptive Transcutaneous Power Transfer to Implantable Devices: A State of the Art Review.

    Science.gov (United States)

    Bocan, Kara N; Sejdić, Ervin

    2016-03-18

    Wireless energy transfer is a broad research area that has recently become applicable to implantable medical devices. Wireless powering of and communication with implanted devices is possible through wireless transcutaneous energy transfer. However, designing wireless transcutaneous systems is complicated due to the variability of the environment. The focus of this review is on strategies to sense and adapt to environmental variations in wireless transcutaneous systems. Adaptive systems provide the ability to maintain performance in the face of both unpredictability (variation from expected parameters) and variability (changes over time). Current strategies in adaptive (or tunable) systems include sensing relevant metrics to evaluate the function of the system in its environment and adjusting control parameters according to sensed values through the use of tunable components. Some challenges of applying adaptive designs to implantable devices are challenges common to all implantable devices, including size and power reduction on the implant, efficiency of power transfer and safety related to energy absorption in tissue. Challenges specifically associated with adaptation include choosing relevant and accessible parameters to sense and adjust, minimizing the tuning time and complexity of control, utilizing feedback from the implanted device and coordinating adaptation at the transmitter and receiver.

  11. Transcutaneous bilirubinometry reduces the need for blood sampling in neonates with visible jaundice.

    Science.gov (United States)

    Mishra, S; Chawla, D; Agarwal, R; Deorari, A K; Paul, V K; Bhutani, V K

    2009-12-01

    We determined usefulness of transcutaneous bilirubinometry to decrease the need for blood sampling to assay serum total bilirubin (STB) in the management of jaundiced healthy Indian neonates. Newborns, > or =35 weeks' gestation, with clinical evidence of jaundice were enrolled in an institutional approved randomized clinical trial. The severity of hyperbilirubinaemia was determined by two non-invasive methods: i) protocol-based visual assessment of bilirubin (VaB) and ii) transcutaneous bilirubin (TcB) determination (BiliCheck). By a random allocation, either method was used to decide the need for blood sampling, which was defined to be present if assessed STB by allocated method exceeded 80% of hour-specific threshold values for phototherapy (2004 AAP Guidelines). A total of 617 neonates were randomized to either TcB (n = 314) or VaB (n = 303) groups with comparable gestation, birth weight and postnatal age. Need for blood sampling to assay STB was 34% lower (95% CI: 10% to 51%) in the TcB group compared with VaB group (17.5% vs 26.4% assessments; risk difference: -8.9%, 95% CI: -2.4% to -15.4%; p = 0.008). Routine use of transcutaneous bilirubinometry compared with systematic visual assessment of bilirubin significantly reduced the need for blood sampling to assay STB in jaundiced term and late-preterm neonates. (ClinicalTrials.gov number, NCT00653874).

  12. Adaptive Transcutaneous Power Transfer to Implantable Devices: A State of the Art Review

    Directory of Open Access Journals (Sweden)

    Kara N. Bocan

    2016-03-01

    Full Text Available Wireless energy transfer is a broad research area that has recently become applicable to implantable medical devices. Wireless powering of and communication with implanted devices is possible through wireless transcutaneous energy transfer. However, designing wireless transcutaneous systems is complicated due to the variability of the environment. The focus of this review is on strategies to sense and adapt to environmental variations in wireless transcutaneous systems. Adaptive systems provide the ability to maintain performance in the face of both unpredictability (variation from expected parameters and variability (changes over time. Current strategies in adaptive (or tunable systems include sensing relevant metrics to evaluate the function of the system in its environment and adjusting control parameters according to sensed values through the use of tunable components. Some challenges of applying adaptive designs to implantable devices are challenges common to all implantable devices, including size and power reduction on the implant, efficiency of power transfer and safety related to energy absorption in tissue. Challenges specifically associated with adaptation include choosing relevant and accessible parameters to sense and adjust, minimizing the tuning time and complexity of control, utilizing feedback from the implanted device and coordinating adaptation at the transmitter and receiver.

  13. Point Spectroscopy System for Noncontact and Noninvasive Prediction of Transcutaneous Bilirubin Concentration

    Science.gov (United States)

    Ong, P. E.; K. C Huong, Audrey

    2017-08-01

    This paper presents the use of a point spectroscopy system to determine one’s transcutaneous bilirubin level using Modified Lambert Beer model and the developed fitting routine. This technique required a priori knowledge of extinction coefficient of bilirubin and hemoglobin components in the wavelength range of 440-500 nm for the prediction of the required parameter value. This work was conducted on different skin sites of six healthy Asians namely on the thenar region of the palm of their hand, back of the hand, posterior and anterior forearm. The obtained results revealed the lowest mean transcutaneous bilirubin concentration of 0.44±0.3 g/l predicted for palm site while the highest bilirubin level of 0.98±0.2 g/l was estimated for posterior forearm. These values were also compared with that presented in the literature. This study found considerably good consistency in the value predicted for different subjects especially at the thenar region of the palm. This work concluded that the proposed system and technique may be suitably served as an alternative means to noncontact and noninvasive measurement of one’s transcutaneous bilirubin level at palm site.

  14. Oxygen toxicity

    Directory of Open Access Journals (Sweden)

    C. A. van der Westhuizen

    1990-07-01

    Full Text Available Oxygen has been discovered about 200 years ago. Since then the vital physiological involvement of oxygen in various biologi­cal processes, mainly energy production, has been established. However, in the body molecular oxygen can be converted to toxic oxygen metabolites such as superoxide anion, hydrogen peroxide, the hydroxyl radical and singlet oxygen. These toxic metabolites are produced mainly in the mitochondria, plasma membranes and endoplasmic reticulum.

  15. Acute effects of transcutaneous electrical diaphragmatic stimulation on respiratory pattern in COPD patients: cross-sectional and comparative clinical trial

    Directory of Open Access Journals (Sweden)

    Karina M. Cancelliero-Gaiad

    2013-12-01

    Full Text Available BACKGROUND: Transcutaneous electrical diaphragmatic stimulation (TEDS has been used to improve respiratory muscle strength in patients with respiratory muscle weakness. However, this physical therapy resource has not been studied in chronic obstructive pulmonary disease (COPD. OBJECTIVE: To evaluate the respiratory pattern during one session of TEDS in COPD patients. METHOD: Fifteen COPD patients participated in one TEDS session for plethysmographic analysis and assessment of peripheral oxygen saturation (SpO2 and heart rate (HR. After the session, patients were divided into two groups: Responder (R; n=9 and Non-Responder (NR; n=6 to TEDS. Statistic analysis was performed using the Shapiro-Wilk normality test and two-way ANOVA. For the parameters that showed interaction, the Student t test was used (P<0.05. RESULTS: R group consisted mainly of men, with lower SpO2 and higher HR than NR group. When time (before and during and groups (R and NR were compared (interaction, there were differences in the parameters minute ventilation (Vent, inspiratory tidal volume (ViVol, expiratory tidal volume (VeVol, and respiratory rate (Br/M. In the intergroup comparison, differences were observed in the parameters Vent, ViVol, and VeVol. A significant effect was also observed for time in change in end-expiratory lung volume level (qDEEL, phase relation during inspiration (PhRIB; phase relation during expiration (PhREB; phase relation of entire breath (PhRTB, and phase angle (PhAng. During TEDS, there was an increase in SpO2 and a reduction in HR in both groups. CONCLUSIONS: The most hypoxemic group with greater HR responded to TEDS and there was interaction between group and time of analysis for the pulmonary volumes. The time factor had an influence on the two groups with an increase in thoracoabdominal asynchrony.

  16. Evaluation of the correlation between transcutaneous measurement andconcentration ofbilirubin inthe blood serum ofa newborn

    Directory of Open Access Journals (Sweden)

    Małgorzata Morawiecka-Pietrzak

    2016-09-01

    Full Text Available Aim: Due to the potential toxicity of high concentrations of bilirubin, newborns are monitored in terms of the potential emergence of a group at risk of the development of severe hyperbilirubinaemia and, rarely, encephalopathy and kernicterus. The transcutaneous measurement of bilirubin, as a non-invasive method, is applied in neonatal centres. The paper presents an evaluation of the correlation between the transcutaneous measurement and the concentration of bilirubin in the blood serum of a newborn, taking into consideration the reduction of the necessity to carry out blood tests related to the transcutaneous measurement. Material and method: The analysis comprised 1,076 medical histories of newborns hospitalised at the Department of Neonatology of the Municipal Hospital in Zabrze in the period from 1 January to 31 December 2013 (a primary referral centre. The inclusion criteria for the study were: performing a simultaneous transcutaneous measurement and a blood serum concentration measurement of bilirubin, gestational age ≥35 Hbd and birth weight >2,500 g. 272 children were qualified for the study. Results: Boys constituted 51.7%, and girls 48.3% of the research group. The mean gestational age was 38.7 Hbd and the mean birth weight was 3,323.4 g; 67.8% of the children were born by natural labour and 32.2% – by caesarean section. The mean Apgar score in the 5th minute was 9.8 points. The measurement of the concentration of bilirubin was performed on average on the 3.9 day of life. The mean transcutaneous measurement was 9.67 mg% (2.7–17.2 mg% and the mean concentration of bilirubin in the blood serum was 13.18 mg% (7.0–19.8 mg%; the difference was 3.5 mg% (p < 0.0001. A statistically significant positive correlation was found between the concentrations of bilirubin obtained in the transcutaneous measurement and the concentrations in the blood serum (according to Spearman, r

  17. Development of pulmonary vascular response to oxygen

    International Nuclear Information System (INIS)

    Morin, F.C. III; Egan, E.A.; Ferguson, W.; Lundgren, C.E.

    1988-01-01

    The ability of the pulmonary circulation of the fetal lamb to respond to a rise in oxygen tension was studied from 94 to 146 days of gestation. The unanesthetized ewe breathed room air at normal atmospheric pressure, followed by 100% oxygen at three atmospheres absolute pressure in a hyperbaric chamber. In eleven near-term lambs, fetal arterial oxygen tension (Pa O 2 ) increased from 25 to 55 Torr, which increased the proportion or right ventricular output distributed to the fetal lungs from 8 to 59%. In five very immature lambs fetal Pa O 2 increased from 27 to 174 Torr, but the proportion of right ventricular output distributed to the lung did not change. In five of the near-term lambs, pulmonary blood flow was measured. For each measurement of the distribution of blood flow, approximately 8 x 10 5 spheres of 15-μm diameter, labeled with either 153 Gd, 113 Sn, 103 Ru, 95 Nb, or 46 Sc were injected. It increased from 34 to 298 ml · kg fetal wt -1 · min -1 , an 8.8-fold increase. The authors conclude that the pulmonary circulation of the fetal lamb does not respond to an increase in oxygen tension before 101 days of gestation; however, near term an increase in oxygen tension alone can induce the entire increase in pulmonary blood flow that normally occurs after the onset of breathing at birth

  18. Oxygen Modulates Human Decidual Natural Killer Cell Surface Receptor Expression and Interactions with Trophoblasts1

    Science.gov (United States)

    Wallace, Alison E.; Goulwara, Sonu S.; Whitley, Guy S.; Cartwright, Judith E.

    2014-01-01

    Decidual natural killer (dNK) cells have been shown to both promote and inhibit trophoblast behavior important for decidual remodeling in pregnancy and have a distinct phenotype compared to peripheral blood NK cells. We investigated whether different levels of oxygen tension, mimicking the physiological conditions of the decidua in early pregnancy, altered cell surface receptor expression and activity of dNK cells and their interactions with trophoblast. dNK cells were isolated from terminated first-trimester pregnancies and cultured in oxygen tensions of 3%, 10%, and 21% for 24 h. Cell surface receptor expression was examined by flow cytometry, and the effects of secreted factors in conditioned medium (CM) on the trophoblast cell line SGHPL-4 were assessed in vitro. SGHPL-4 cells treated with dNK cell CM incubated in oxygen tensions of 10% were significantly more invasive (P cells treated with dNK cell CM incubated in oxygen tensions of 3% or 21%. After 24 h, a lower percentage of dNK cells expressed CD56 at 21% oxygen (P cells expressed NKG2D at 10% oxygen (P oxygen tensions, with large patient variation. This study demonstrates dNK cell phenotype and secreted factors are modulated by oxygen tension, which induces changes in trophoblast invasion and endovascular-like differentiation. Alterations in dNK cell surface receptor expression and secreted factors at different oxygen tensions may represent regulation of function within the decidua during the first trimester of pregnancy. PMID:25232021

  19. The Plastic Tension Field Method

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2005-01-01

    This paper describes a calculation method for steel plate girders with transverse web stiffeners subjected to shear. It may be used for predicting the failure load or, as a design method, to determine the optimal amount of internal web stiffeners. The new method is called the plastic tension field...... method. The method is based on the theory of plasticity and is analogous to the so-called diagonal compression field method developed for reinforced concrete beams with transverse stirrups, which is adopted in the common European concrete code (Eurocode 2). Many other theories have been developed...

  20. Axelrod's model with surface tension

    Science.gov (United States)

    Pace, Bruno; Prado, Carmen P. C.

    2014-06-01

    In this work we propose a subtle change in Axelrod's model for the dissemination of culture. The mechanism consists of excluding from the set of potentially interacting neighbors those that would never possibly exchange. Although the alteration proposed does not alter the state space topologically, it yields significant qualitative changes, specifically the emergence of surface tension, driving the system in some cases to metastable states. The transient behavior is considerably richer, and cultural regions become stable leading to the formation of different spatiotemporal patterns. A metastable "glassy" phase emerges between the globalized phase and the disordered, multicultural phase.

  1. Update on normal tension glaucoma

    Directory of Open Access Journals (Sweden)

    Jyotiranjan Mallick

    2016-01-01

    Full Text Available Normal tension glaucoma (NTG is labelled when typical glaucomatous disc changes, visual field defects and open anterior chamber angles are associated with intraocular pressure (IOP constantly below 21 mmHg. Chronic low vascular perfusion, Raynaud's phenomenon, migraine, nocturnal systemic hypotension and over-treated systemic hypertension are the main causes of normal tension glaucoma. Goldmann applanation tonometry, gonioscopy, slit lamp biomicroscopy, optical coherence tomography and visual field analysis are the main tools of investigation for the diagnosis of NTG. Management follows the same principles of treatment for other chronic glaucomas: To reduce IOP by a substantial amount, sufficient to prevent disabling visual loss. Treatment is generally aimed to lower IOP by 30% from pre-existing levels to 12-14 mmHg. Betaxolol, brimonidine, prostaglandin analogues, trabeculectomy (in refractory cases, systemic calcium channel blockers (such as nifedipine and 24-hour monitoring of blood pressure are considered in the management of NTG. The present review summarises risk factors, causes, pathogenesis, diagnosis and management of NTG.

  2. Oxygen Therapy

    Science.gov (United States)

    ... their breathing to dangerously low levels. Will I need oxygen when I sleep? Usually if you use supplemental oxygen during the ... your health care provider tells you you only need to use oxygen for exercise or sleep. Even if you feel “fine” off of your ...

  3. Comparison of skin sensory thresholds using pre-programmed or single-frequency transcutaneous electrical nerve stimulation.

    Science.gov (United States)

    Kang, Jong Ho

    2015-12-01

    [Purpose] The purpose of the present study was to compare the sensory thresholds of healthy subjects using pre-programmed or single-frequency transcutaneous electrical nerve stimulation. [Subjects] Ninety healthy adult subjects were randomly assigned to pre-programmed or single-frequency stimulation groups, each consisting of 45 participants. [Methods] Sensory thresholds were measured in the participants' forearms using von Frey filaments before and after pre-programmed or single-frequency transcutaneous electrical nerve stimulation, and the result in values were analyzed. [Results] Significant increases in sensory threshold after stimulation were observed in both groups. However, there were no significant differences between the two groups in sensory thresholds after stimulation or in the magnitude of threshold increases following stimulation. [Conclusion] Our results show that there are no differences between sensory threshold increases induced by pre-programmed and single-frequency transcutaneous electrical nerve stimulation.

  4. A Comparison between Transcutaneous and Total Serum Bilirubin in Healthy-term Greek Neonates with Clinical Jaundice

    Directory of Open Access Journals (Sweden)

    Charalambos Neocleous

    2014-01-01

    Full Text Available The accuracy of transcutaneous bilirubin meters has been assessed in newborns from various ethnic backgrounds. However, there are limited data on Greek newborns. Our study examined the accuracy of transcutaneous bilirubin measurements in clinically jaundiced healthy-term Greek newborns, using total serum bilirubin as the reference standard, in order to re-evaluate our local guidelines about neonatal jaundice. Clinically jaundiced newborns requiring total serum bilirubin level estimation were recruited prospectively. 368 pairs of total serum bilirubin/transcutaneous bilirubin measurements were taken in 222 newborns, using a direct spectrophotometric device and the BiliCheck device, respectively. The level of agreement between the obtained transcutaneous bilirubin and total serum bilirubin values was assessed. Our data were analysed using the Stata/SE 12.0 (StataCorp LP, USA statistical programme. The mean (± SD TSB was 225.4 ± 25.4 μmol/l and the mean (± SD TcB was 237.9 ± 21.0 μmol/l. The correlation between the values was poor (Pearson’s correlation coefficient 0.439; Lin’s concordance coefficient 0.377 [95% CI 0.301 to 0.453]; P<0.001. The Bland-Altman analysis demonstrated that transcutaneous bilirubin measurements tended to overestimate the total serum bilirubin value (mean difference 12.5 ± 24.9 μmol/l, with wide 95% limits of agreement (–36.2 μmol/l to 61.3 μmol/l. Transcutaneous bilirubin values did not correlate well with total serum bilirubin values, being often imprecise in predicting the actual total serum bilirubin levels. This permits us to continue estimating total serum bilirubin in clinically jaundiced newborns according to our local guidelines, in order to safely decide the appropriate care plan.

  5. The study and design of tension controller

    Science.gov (United States)

    Jun, G.; Lamei, X.

    2018-02-01

    Tension control is a wide used technology in areas such as textiles, paper and plastic films. In this article, the tension control system release and winding process is analyzed and the mathematical model of tension control system is established, and a high performance tension controller is designed. In hardware design, STM32F130 single chip microcomputer is used as the control core, which has the characteristics of fast running speed and rich peripheral features. In software design, μC/OS-II operating system is introduced to improve the efficiency of single chip microcomputer, and enhance the independence of each module, and make development and maintenance more convenient. The taper tension control is adopted in the winding part, which can effectively solve the problem of rolling shrinkage. The results show that the tension controller has the characteristics of simple structure, easy operation and stable performance.

  6. 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.

  7. The Equilibrium Spreading Tension of Pulmonary Surfactant

    OpenAIRE

    Dagan, Maayan P.; Hall, Stephen B.

    2015-01-01

    Monomolecular films at an air/water interface coexist at the equilibrium spreading tension (γe) with the bulk phase from which they form. For individual phospholipids, γe is single-valued, and separates conditions at which hydrated vesicles adsorb from tensions at which overcompressed monolayers collapse. With pulmonary surfactant, isotherms show that monolayers compressed on the surface of bubbles coexist with the three-dimensional collapsed phase over a range of surface tensions. γe therefo...

  8. Intervention of oxygen-control ability to radiation sensitivity, cell aging and cell transformation

    International Nuclear Information System (INIS)

    Yoshii, Hanako; Watanabe, Masami

    2009-01-01

    Oxygen is essential for life, and cells have therefore developed numerous adaptive responses to oxygen change. Here, we examined the difference in oxygen-control functions of human (HE), mouse (ME), and Syrian hamster embryo (SHE) cells cultured under different oxygen conditions (0.5%, 2% and 20%), and also examined whether oxygen tensions contributed to cellular lifespan and transformation. HE cells had their replicative lifespan slightly extended under hypoxic (0.5% and 2% oxygen) conditions, but were not immortalized under any of the oxygen concentrations. On the other hand, although ME cells cultured under 20% oxygen tension decreased their proliferation potency temporarily at early stage, all rodent cells were immortalized and acquired anchorage-independency, regardless of oxygen tension. These results suggest that cellular oxygen control function is related to sensitivities cellular immortalization and transformation. To understand intervention of oxygen control ability on cellular immortalization and transformation, we examined the intracellular oxidative level, mitochondria functions and radiation sensitivity. Intracellular oxidative levels of hypoxically cultured rodent cells were significantly enhanced. Mitochondrial membrane potential was altered depend on oxygen tensions, but the change was not parallel to mitochondria number in rodent cells. ME cells were particularly sensitive to oxygen change, and showed a clear oxygen effect on the X-ray survival. However, there was no difference in frequency of radiation-induced micronuclei between HE and ME cells. These results suggest that the response to oxygen change differs markedly in HE and rodent cells. (author)

  9. Transcutaneous spinal stimulation as a therapeutic strategy for spinal cord injury: state of the art

    Directory of Open Access Journals (Sweden)

    Grecco LH

    2015-03-01

    Full Text Available Leandro H Grecco,1,3,4,* Shasha Li,1,5,* Sarah Michel,1,6,* Laura Castillo-Saavedra,1 Andoni Mourdoukoutas,7 Marom Bikson,7 Felipe Fregni1,21Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, 2Spaulding-Harvard Spinal Cord Injury Model System, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, USA; 3Special Laboratory of Pain and Signaling, Butantan Institute, 4Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil; 5Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China; 6Department of Pharmacy and Biomedical Sciences, University of Namur, Belgium; 7Department of Biomedical Engineering, The City College of New York, New York, NY, USA*These authors contributed equally to this workAbstract: Treatments for spinal cord injury (SCI still have limited effects. Electrical stimulation might facilitate plastic changes in affected spinal circuitries that may be beneficial in improving motor function and spasticity or SCI-related neuropathic pain. Based on available animal and clinical evidence, we critically reviewed the physiological basis and therapeutic action of transcutaneous spinal cord stimulation in SCI. We analyzed the literature published on PubMed to date, looking for the role of three main noninvasive stimulation techniques in the recovery process of SCI and focusing mainly on transcutaneous spinal stimulation. This review discusses the main clinical applications, latest advances, and limitations of noninvasive electrical stimulation of the spinal cord. Although most recent research in this topic has focused on transcutaneous spinal direct current stimulation (tsDCS, we also reviewed the technique of transcutaneous electric nerve stimulation (TENS and neuromuscular electrical stimulation (NMES as potential methods to modulate spinal cord

  10. Novel diode-based laser system for combined transcutaneous monitoring and computer-controlled intermittent treatment of jaundiced neonates

    Science.gov (United States)

    Hamza, Mostafa; El-Ahl, Mohammad H. S.; Hamza, Ahmad M.

    2001-06-01

    The high efficacy of laser phototherapy combined with transcutaneous monitoring of serum bilirubin provides optimum safety for jaundiced infants from the risk of bilirubin encephalopathy. In this paper the authors introduce the design and operating principles of a new laser system that can provide simultaneous monitoring and treatment of several jaundiced babies at one time. The new system incorporates diode-based laser sources oscillating at selected wavelengths to achieve both transcutaneous differential absorption measurements of bilirubin concentration in addition to the computer controlled intermittent laser therapy through a network of optical fibers. The detailed description and operating characteristics of this system are presented.

  11. Oxygen Therapy

    Directory of Open Access Journals (Sweden)

    Bonnie Solmes

    2000-01-01

    Full Text Available LTOT is prescribed for people with chronic lung disease in whom there is a decrease in the ability of the lungs to supply enough oxygen to the body. The heart is obliged to pump faster to meet the body's oxygen requirements. This may place undue stress on the heart, resulting in palpitations, dizziness and fatigue. A low oxygen level in arterial blood is also harmful to the heart, the brain and the pulmonary blood vessels. Oxygen therapy is used to break this cycle. A person with low blood oxygen will often be able to accomplish more with less fatigue with the help of supplemental oxygen therapy. Shortness of breath is a mechanical problem resulting from the effects of chronic obstructive pulmonary disease. Oxygen therapy may or may not reduce shortness of breath, but it will help the lungs and heart to function with less stress.

  12. Flexible nine-channel photodetector probe facilitated intraspinal multisite transcutaneous photobiomodulation therapy dosimetry in cadaver dogs

    Science.gov (United States)

    Piao, Daqing; Sypniewski, Lara A.; Bailey, Christian; Dugat, Danielle; Burba, Daniel J.; De Taboada, Luis

    2018-01-01

    Noninvasive photobiomodulation therapy (PBMT) of spinal cord disease remains speculative due to the lack of evidence for whether photobiomodulatory irradiances can be transcutaneously delivered to the spinal cord under a clinically acceptable PBMT surface irradiation protocol. We developed a flexible nine-channel photodetection probe for deployment within the spinal canal of a cadaver dog after hemilaminectomy to measure transcutaneously transmitted PBMT irradiance at nine sites over an eight-cm spinal canal length. The probe was built upon a 6.325-mm tubular stem, to the surface of which nine photodiodes were epoxied at approximately 1 cm apart. The photodiode has a form factor of 4.80 mm×2.10 mm×1.15 mm (length×width×height). Each photodiode was individually calibrated to deliver 1 V per 7.58 μW/cm2 continuous irradiance at 850 nm. The outputs of eight photodiodes were logged concurrently using a data acquisition module interfacing eight channels of differential analog signals, while the output of the ninth photodiode was measured by a precision multimeter. This flexible probe rendered simultaneous intraspinal (nine-site) measurements of transcutaneous PBMT irradiations at 980 nm in a pilot cadaver dog model. At a surface continuous irradiance of 3.14 W/cm2 applied off-contact between L1 and L2, intraspinal irradiances picked up by nine photodiodes had a maximum of 327.48 μW/cm2 without the skin and 5.68 μW/cm2 with the skin.

  13. Transcutaneous glomerular filtration rate measurement in a canine animal model of chronic kidney disease.

    Science.gov (United States)

    Mondritzki, Thomas; Steinbach, Sarah M L; Boehme, Philip; Hoffmann, Jessica; Kullmann, Maximilian; Schock-Kusch, Daniel; Vogel, Julia; Kolkhof, Peter; Sandner, Peter; Bischoff, Erwin; Hüser, Jörg; Dinh, Wilfried; Truebel, Hubert

    Quantitative assessment of renal function by measurement of glomerular filtration rate (GFR) is an important part of safety and efficacy evaluation in preclinical drug development. Existing methods are often time consuming, imprecise and associated with animal burden. Here we describe the comparison between GFR determinations with sinistrin (PS-GFR) and fluorescence-labelled sinistrin-application and its transcutaneous detection (TD-GFR) in a large animal model of chronic kidney disease (CKD). TD-GFR measurements compared to a standard method using i.v. sinistrin were performed in a canine model. Animals were treated with one-sided renal wrapping (RW) followed by renal artery occlusion (RO). Biomarker and remote hemodynamic measurements were performed. Plasma sinistrin in comparison to transcutaneous derived GFR data were determined during healthy conditions, after RW and RW+RO. RW alone did not led to any significant changes in renal function, neither with PS-GFR nor TD-GFR. Additional RO showed a rise in blood pressure (+68.0mmHg), plasma urea (+28.8mmol/l), creatinine (+224,4μmol/l) and symmetric dimethylarginine (SDMA™; +12.6μg/dl). Plasma sinistrin derived data confirmed the expected drop (-44.7%, p<0.0001) in GFR. The calculated transcutaneous determined Fluorescein Isothiocyanate (FITC)-sinistrin GFR showed no differences to plasma sinistrin GFR at all times. Both methods were equaly sensitive to diagnose renal dysfunction in the affected animals. Renal function assessment using TD-GFR is a valid method to improve preclinical drug discovery and development. Furthermore, TD-GFR method offers advantages in terms of reduced need for blood sampling and thus decreasing animal burden compared to standard procedures. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Tension pneumothorax accompanied by type A aortic dissection.

    Science.gov (United States)

    Hifumi, Toru; Kiriu, Nobuaki; Inoue, Junichi; Koido, Yuichi

    2012-11-09

    A 51-year-old man was brought to the emergency room because of a sudden onset of severe dysponea. On presentation, his blood pressure was 94/55 mm Hg. Oxygen saturation was 86% while he was receiving 10 l/min oxygen through a non-rebreather mask. On physical examination, no jugular venous distention was noted, but breath sounds over the left lung were diminished. A bedside chest radiograph showed left tension pneumothorax, for which urgent needle decompression followed by chest thoracostomy was performed. Ventricular tachycardia developed, but a biphasic shock at 120 J immediately restored normal sinus rhythm. His vital signs, however, did not improve. A CT scan of the chest showed type A aortic dissection with bullae in the upper lobe of the left lung. He had an emergency operation for distal aortic arch displacement and was discharged on the 37th day of hospitalisation.

  15. Actin filaments as tension sensors.

    Science.gov (United States)

    Galkin, Vitold E; Orlova, Albina; Egelman, Edward H

    2012-02-07

    The field of mechanobiology has witnessed an explosive growth over the past several years as interest has greatly increased in understanding how mechanical forces are transduced by cells and how cells migrate, adhere and generate traction. Actin, a highly abundant and anomalously conserved protein, plays a large role in forming the dynamic cytoskeleton that is so essential for cell form, motility and mechanosensitivity. While the actin filament (F-actin) has been viewed as dynamic in terms of polymerization and depolymerization, new results suggest that F-actin itself may function as a highly dynamic tension sensor. This property may help explain the unusual conservation of actin's sequence, as well as shed further light on actin's essential role in structures from sarcomeres to stress fibers. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Neuralgia associated with transcutaneous electrical nerve stimulation therapy in a patient initially diagnosed with temporomandibular disorder.

    Science.gov (United States)

    Omolehinwa, Temitope T; Musbah, Thamer; Desai, Bhavik; O'Malley, Bert W; Stoopler, Eric T

    2015-03-01

    Head and neck neoplasms may be difficult to detect because of wide-ranging symptoms and the presence of overlapping anatomic structures in the region. This case report describes a patient with chronic otalgia and temporomandibular disorder, who developed sudden-onset neuralgia while receiving transcutaneous electrical nerve stimulation (TENS) therapy. Further diagnostic evaluation revealed a skull base tumor consistent with adenoid cystic carcinoma. To our knowledge, this is the first report of TENS-associated neuralgia leading to a diagnosis of primary intracranial adenoid cystic carcinoma. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Matrix stiffness and oxigen tension modulate epigenetic conversion of mouse dermal fibroblasts into insulin producing cells.

    Directory of Open Access Journals (Sweden)

    Alessandro Zenobi

    2017-05-01

    Full Text Available In vivo, cells are surrounded by a three-dimensional (3-D organization of supporting matrix, neighboring cells and a gradient of chemical and mechanical signals (Antoni, et al., 2015. However, the present understanding of many biological processes is mainly based on two-dimensional (2-D systems that typically provides a static environment. In the present study, we tested two different 3-D culture systems and apply them to the epigenetic conversion of mouse dermal fibroblasts into insulin producing-cells (Pennarossa, et al., 2013; Brevini, et al., 2015, combining also the use of two oxygen tensions. In particular, cells were differentiated using the Polytetrafluoroethylene micro-bioreactor (PTFE and the Polyacrylamide (PAA gels with different stiffness (1 kPa; 4 kPa, maintained either in the standard 20% or in the more physiological 5% oxygen tensions. Standard differentiation performed on plastic substrates was assessed as a control. Cell morphology (Fig.1A, insulin expression and release were analyzed to evaluate the role of both stiffness and oxygen tension in the process. The results obtained showed that 1 kPa PAA gel and PTFE system induced a significantly higher insulin expression and release than plastic and 4 kPa PAA gel, especially in low oxygen condition (Fig.1B. Furthermore, comparing the efficiency of the two systems tested, 1 kPa PAA gel ensured a higher insulin transcription than PTFE (Fig.1C. Recent studies show the direct influence of substrates on lineage commitment and cell differentiation (Engler, et al., 2006; Evans, et al., 2009. The evidence here presented confirm that the use of an appropriate stiffness (similar to the pancreatic tissue, combined with a physiological oxygen tension, promote β-cell differentiation, with beneficial effects on cell functional activity and insulin release. The present results highlight the importance of 3-D cell rearrangement and oxigen tension to promote in vitro epigenetic conversion of

  18. Oxygen status during haemodialysis. The Cord-Group

    DEFF Research Database (Denmark)

    Nielsen, A L; Jensen, H Æ; Hegbrant, J

    1995-01-01

    Hypoxia during haemodialysis, mainly acetate, has been reported several times. In our study we have monitored oxygen status during 258 bicarbonate haemodialyses. A significant drop below 80 mmHg in mean oxygen tension occurred. Mean oxygen saturation reflected this drop but did not reach levels...... below 90%. The mean oxygen concentration was on the whole critical low, though slightly increasing during each haemodialysis session due to ultrafiltration. It is concluded that both hypoxia and hypoxaemia do occur during bicarbonate haemodialysis. To a group of patients generally having limited cardiac...... reserves, a poor oxygen status is a potentially serious complication to haemodialysis. Monitoring oxygen status is thus advisable....

  19. Preliminary study on carprofen concentration measurements after transcutaneous treatment with Vetdrop® in a microfracture joint defect model in sheep.

    Science.gov (United States)

    Sidler, Michèle; Fouché, Nathalie; Meth, Ingmar; von Hahn, Friedrich; von Rechenberg, Brigitte; Kronen, Peter W

    2014-12-09

    The present preliminary study describes concentration time courses of the NSAID carprofen in the plasma and synovial fluid in a microfrature sheep model after transcutaneous treatments with a novel application device (Vetdrop®). To treat circumscribed inflammatory processes a transcutaneous application device could potentially be beneficial. After transcutaneous application normally lower systemic concentrations are measured which may reduce the incidence of side effects, whereas efficacy is still maintained. In this study carprofen was used based on its capacity to provide analgesia after orthopaedic procedures in sheep and it is considered that it may have a positive influence on the healing of cartilage in low concentrations. In all transcutaneously treated animals, carprofen plasma concentrations exceeded those of synovial fluid, although plasma levels remained significantly reduced (300-fold) as compared to carprofen administered intravenously. Furthermore, in contrast to the intravenously treated animals, a modest accumulation of carprofen in plasma and synovial fluid was observed in the transcutaneously treated animals over the 6-week treatment period. The transcutaneously administered carprofen using the Vetdrop® device penetrated the skin and both, plasma- and synovial concentrations could be measured repeatedly over time. This novel device may be considered a valuable transcutaneous drug delivery system.

  20. Cerebral oxygenation is reduced during hyperthermic exercise in humans

    DEFF Research Database (Denmark)

    Rasmussen, Peter; Nybo, Lars; Volianitis, S.

    2010-01-01

    Abstract Aim: Cerebral mitochondrial oxygen tension (P(mito)O(2)) is elevated during moderate exercise, while it is reduced when exercise becomes strenuous, reflecting an elevated cerebral metabolic rate for oxygen (CMRO(2)) combined with hyperventilation-induced attenuation of cerebral blood flo...

  1. Tricyclic and Tetracyclic Antidepressants for the Prevention of Frequent Episodic or Chronic Tension-Type Headache in Adults: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Jackson, Jeffrey L; Mancuso, Josephine M; Nickoloff, Sarah; Bernstein, Rebecca; Kay, Cynthia

    2017-12-01

    Tension-type headaches are a common source of pain and suffering. Our purpose was to assess the efficacy of tricyclic (TCA) and tetracyclic antidepressants in the prophylactic treatment of tension-type headache. We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, the ISI Web of Science, and clinical trial registries through 11 March 2017 for randomized controlled studies of TCA or tetracyclic antidepressants in the prevention of tension-type headache in adults. Data were pooled using a random effects approach. Among 22 randomized controlled trials, eight included a placebo comparison and 19 compared at least two active treatments. Eight studies compared TCAs to placebo, four compared TCAs to selective serotonin reuptake inhibitors (SSRIs), and two trials compared TCAs to behavioral therapies. Two trials compared tetracyclics to placebo. Single trials compared TCAs to tetracyclics, buspirone, spinal manipulation, transcutaneous electrical stimulation, massage, and intra-oral orthotics. High-quality evidence suggests that TCAs were superior to placebo in reducing headache frequency (weighted mean differences (WMD): -4.8 headaches/month, 95% CI: -6.63 to -2.95) and number of analgesic medications consumed (WMD: -21.0 doses/month, 95% CI: -38.2 to -3.8). TCAs were more effective than SSRIs. Low-quality studies suggest that TCAs are superior to buspirone, but equivalent to behavioral therapy, spinal manipulation, intra-oral orthotics, and massage. Tetracyclics were no better than placebo for chronic tension-type headache. Tricyclic antidepressants are modestly effective in reducing chronic tension-type headache and are superior to buspirone. In limited studies, tetracyclics appear to be ineffective in the prophylactic treatment of chronic tension-type headache.

  2. Normal-tension glaucoma (Low-tension glaucoma)

    Science.gov (United States)

    Anderson, Douglas R

    2011-01-01

    Glaucoma is now considered an abnormal physiology in the optic nerve head that interacts with the level of intraocular pressure (IOP), with the degree and rate of damage depending on the IOP and presumably the degree of abnormal physiology. Diagnosis of normal-tension glaucoma (NTG), defined as glaucoma without a clearly abnormal IOP, depends on recognizing symptoms and signs associated with optic nerve vulnerability, in addition to absence of other explanations for disc abnormality and visual field loss. Among the findings are a halo or crescent of absence of retinal pigment epithelium around the disc, bilateral pre-chiasmal visual field defects, splinter hemorrhages at the disc margin, vascular dysregulation (low blood pressure, cold hands and feet, migraine headache with aura, and the like), or a family history of glaucoma. Possibly relevant, is a history of hemodynamic crisis, arterial obstructive disease, or sleep apnea. Neurological evaluation with imaging is needed only for atypical cases or ones that progress unexpectedly. Management follows the same principle of other chronic glaucomas, to lower the IOP by a substantial amount, enough to prevent disabling visual loss. However, many NTG cases are non-progressive. Therefore, it may often be wisein mild cases to determine whether the case is progressive and the rate of progression before deciding on how aggressivene to be with therapy. Efforts at neuroprotection and improvement in blood flow have not yet been shown effective. PMID:21150042

  3. Normal-tension glaucoma (Low-tension glaucoma

    Directory of Open Access Journals (Sweden)

    Anderson Douglas

    2011-12-01

    Full Text Available Glaucoma is now considered an abnormal physiology in the optic nerve head that interacts with the level of intraocular pressure (IOP, with the degree and rate of damage depending on the IOP and presumably the degree of abnormal physiology. Diagnosis of normal-tension glaucoma (NTG, defined as glaucoma without a clearly abnormal IOP, depends on recognizing symptoms and signs associated with optic nerve vulnerability, in addition to absence of other explanations for disc abnormality and visual field loss. Among the findings are a halo or crescent of absence of retinal pigment epithelium around the disc, bilateral pre-chiasmal visual field defects, splinter hemorrhages at the disc margin, vascular dysregulation (low blood pressure, cold hands and feet, migraine headache with aura, and the like, or a family history of glaucoma. Possibly relevant, is a history of hemodynamic crisis, arterial obstructive disease, or sleep apnea. Neurological evaluation with imaging is needed only for atypical cases or ones that progress unexpectedly. Management follows the same principle of other chronic glaucomas, to lower the IOP by a substantial amount, enough to prevent disabling visual loss. However, many NTG cases are non-progressive. Therefore, it may often be wisein mild cases to determine whether the case is progressive and the rate of progression before deciding on how aggressivene to be with therapy. Efforts at neuroprotection and improvement in blood flow have not yet been shown effective.

  4. The efficacy of transcutaneous electrical nerve stimulation on the improvement of walking distance in patients with peripheral arterial disease with intermittent claudication: study protocol for a randomised controlled trial: the TENS-PAD study.

    Science.gov (United States)

    Besnier, Florent; Sénard, Jean-Michel; Grémeaux, Vincent; Riédel, Mélanie; Garrigues, Damien; Guiraud, Thibaut; Labrunée, Marc

    2017-08-10

    In patients with peripheral arterial disease (PAD), walking improvements are often limited by early pain onset due to vascular claudication. It would thus appear interesting to develop noninvasive therapeutic strategies, such as transcutaneous electrical nerve stimulation (TENS), to improve the participation of PAD patients in rehabilitation programmes, and thus improve their quality of life. Our team recently tested the efficacy of a single 45-min session of 10-Hz TENS prior to walking. TENS significantly delayed pain onset and increased the pain-free walking distance in patients with class-II PAD. We now seek to assess the efficacy of a chronic intervention that includes the daily use of TENS for 3 weeks (5 days a week) on walking distance in Leriche-Fontaine stage-II PAD patients. This is a prospective, double-blind, multicentre, randomised, placebo-controlled trial. One hundred subjects with unilateral PAD (Leriche-Fontaine stage II) will be randomised into two groups (1:1). For the experimental group (TENS group): the treatment will consist of stimulation of the affected leg (at a biphasic frequency of 10 Hz, with a pulse width of 200 μs, maximal intensity below the motor threshold) for 45 min per day, in the morning before the exercise rehabilitation programme, for 3 weeks, 5 days per week. For the control group (SHAM group): the placebo stimulation will be delivered according to the same modalities as for the TENS group but with a voltage level automatically falling to zero after 10 s of stimulation. First outcome: walking distance without pain. transcutaneous oxygen pressure (TcPO 2 ) measured during a Strandness exercise test, peak oxygen uptake (VO 2 peak), endothelial function (EndoPAT®), Ankle-brachial Pressure Index, Body Mass Index, lipid profile (LDL-C, HDL-C, triglycerides), fasting glycaemia, HbA1c level, and the WELCH questionnaire. TENS-PAD is the first randomised controlled trial that uses transcutaneous electrical therapy as an

  5. Traumatic tension pneumocephalus: Two case reports

    Directory of Open Access Journals (Sweden)

    Abubaker Al-Aieb

    2017-01-01

    Conclusions: These are two rare cases with posttraumatic tension pneumocephalus treated conservatively with a favorable outcome. Early diagnosis of tension pneumocephalus is a crucial step to facilitate early recovery; however, the associated injuries need attention as they could influence the hospital course.

  6. Embracing Tensions in Feminist Organizational Communication Pedagogies

    Science.gov (United States)

    Linabary, Jasmine R.; Long, Ziyu; Mouton, Ashton; Rao, Ranjani L.; Buzzanell, Patrice M.

    2017-01-01

    Feminist pedagogies hold potential to create more inclusive and transformative classrooms. Adopting a tension-centered approach, we draw on our individual and collective reflections on the design and instruction of a multi-section undergraduate organizational communication course to build an autoethnographic account of the tensions associated with…

  7. Tending the tensions in co-creation

    DEFF Research Database (Denmark)

    Phillips, Professor MSO Louise; Nordentoft, Helle Merete; Pedersen, Lektor Christina Hee

    -for-granted positive value. In the panel we de-romanticise “co-creation” and explore how it is enacted in particular organisational contexts, concentrating on context-specific tensions arising in the meeting between different knowledge forms and interests. These include tensions BETWEEN dialogic views of knowledge co-creation...

  8. Post-tensioning system surveillance program

    International Nuclear Information System (INIS)

    Drew, G.E.

    1979-01-01

    Nuclear power plant containment structure post-tensioning system tendon surveillance program is described in detail. Data collected over three yearly post-tensioning system Surveillance Programs is presented and evaluated to correlate anticipated stress losses with actual losses. In addition corrosion protected system performance is analyzed

  9. Tension and robustness in multitasking cellular networks.

    Directory of Open Access Journals (Sweden)

    Jeffrey V Wong

    Full Text Available Cellular networks multitask by exhibiting distinct, context-dependent dynamics. However, network states (parameters that generate a particular dynamic are often sub-optimal for others, defining a source of "tension" between them. Though multitasking is pervasive, it is not clear where tension arises, what consequences it has, and how it is resolved. We developed a generic computational framework to examine the source and consequences of tension between pairs of dynamics exhibited by the well-studied RB-E2F switch regulating cell cycle entry. We found that tension arose from task-dependent shifts in parameters associated with network modules. Although parameter sets common to distinct dynamics did exist, tension reduced both their accessibility and resilience to perturbation, indicating a trade-off between "one-size-fits-all" solutions and robustness. With high tension, robustness can be preserved by dynamic shifting of modules, enabling the network to toggle between tasks, and by increasing network complexity, in this case by gene duplication. We propose that tension is a general constraint on the architecture and operation of multitasking biological networks. To this end, our work provides a framework to quantify the extent of tension between any network dynamics and how it affects network robustness. Such analysis would suggest new ways to interfere with network elements to elucidate the design principles of cellular networks.

  10. Tension Pneumothorax following an Accidental Kerosene Poisoning ...

    African Journals Online (AJOL)

    Tension pneumothorax is a rare complication following an accidental kerosene poisoning. In such situation, a bed-side needle thoracocentesis is performed because of its potential of becoming fatal; hence its clinical importance. A case of 15 month old boy with tension pneumothorax following accidental kerosene ...

  11. Initial tension loss in cerclage cables.

    Science.gov (United States)

    Ménard, Jérémie; Émard, Maxime; Canet, Fanny; Brailovski, Vladimir; Petit, Yvan; Laflamme, George Y

    2013-10-01

    Cerclage cables, frequently used in the management of fractures and osteotomies, are associated with a high failure rate and significant loosening during surgery. This study compared the capacity to maintain tension of different types of orthopaedic cable systems. Multifilament Cobalt-Chrome (CoCr) cables with four different crimp/clamp devices (DePuy, Stryker, Zimmer and Smith&Nephew) and one non-metallic Nylon (Ny) cable from Kinamed were instrumented with a load cell to measure tension during insertion. Significant tension loss was observed with crimping for all cables (Ptensioner led to an additional unexpected tension loss (CoCr-DePuy: 18%, CoCr-Stryker: 29%, CoCr-Smith&Nephew: 33%, Ny: 46%, and CoCr-Zimmer: 52%). The simple CoCr (DePuy) cable system outperformed the more sophisticated locking devices due to its significantly better ability to prevent tension loss. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Can the human lumbar posterior columns be stimulated by transcutaneous spinal cord stimulation? A modeling study.

    Science.gov (United States)

    Danner, Simon M; Hofstoetter, Ursula S; Ladenbauer, Josef; Rattay, Frank; Minassian, Karen

    2011-03-01

    Stimulation of different spinal cord segments in humans is a widely developed clinical practice for modification of pain, altered sensation, and movement. The human lumbar cord has become a target for modification of motor control by epidural and, more recently, by transcutaneous spinal cord stimulation. Posterior columns of the lumbar spinal cord represent a vertical system of axons and when activated can add other inputs to the motor control of the spinal cord than stimulated posterior roots. We used a detailed three-dimensional volume conductor model of the torso and the McIntyre-Richard-Grill axon model to calculate the thresholds of axons within the posterior columns in response to transcutaneous lumbar spinal cord stimulation. Superficially located large-diameter posterior column fibers with multiple collaterals have a threshold of 45.4 V, three times higher than posterior root fibers (14.1 V). With the stimulation strength needed to activate posterior column axons, posterior root fibers of large and small diameters as well as anterior root fibers are coactivated. The reported results inform on these threshold differences, when stimulation is applied to the posterior structures of the lumbar cord at intensities above the threshold of large-diameter posterior root fibers. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  13. Effects and Mechanisms of Transcutaneous Electroacupuncture on Chemotherapy-Induced Nausea and Vomiting

    Directory of Open Access Journals (Sweden)

    Xing Zhang

    2014-01-01

    Full Text Available Nausea and vomiting are one of the major complications of chemotherapy for cancers. The aim of this study is to investigate the emetic effects and mechanisms involving serotonin and dopamine of needleless transcutaneous electroacupuncture (TEA at Neiguan (PC6 and Jianshi (PC5 on chemotherapy-induced nausea and vomiting in patients with cancers. Seventy-two patients with chemotherapy were randomly divided into sham-TEA group (sham-TEA, n=34 and TEA group (n=38. TEA was performed at PC 6 and PC 5 (1 h, bid in combination with granisetron. Sham-TEA was delivered at nonacupoints using the same parameters. We found the following. (1 In the acute phase, the conventional antiemetic therapy using Ondansetron effectively reduced nausea and vomiting; the addition of TEA did not show any additive effects. In the delayed phase, however, TEA significantly increased the rate of complete control (P<0.01 and reduced the nausea score (P<0.05, compared with sham-TEA. (2 TEA significantly reduced serum levels of 5-HT and dopamine in comparison with sham-TEA. Those results demonstrate that needleless transcutaneous electroacupuncture at PC6 using a watch-size digital stimulator improves emesis and reduces nausea in the delayed phase of chemotherapy in patients with cancers. This antiemetic effect is possibly mediated via mechanisms involving serotonin and dopamine.

  14. Evaluation of BiliCare™ transcutaneous bilirubin device in Japanese newborns.

    Science.gov (United States)

    Yamana, Keiji; Morioka, Ichiro; Kurokawa, Daisuke; Fukushima, Sachiyo; Nishida, Kosuke; Ohyama, Shohei; Nishimura, Noriyuki; Nozu, Kandai; Taniguchi-Ikeda, Mariko; Nagase, Hiroaki; Fujioka, Kazumichi; Iwatani, Sota; Nakamura, Hajime; Iijima, Kazumoto

    2017-10-01

    Non-invasive transcutaneous bilirubin (TcB) monitoring has been widely used to screen for hyperbilirubinemia. TcB measured using the recently developed BiliCare™ system, however, has not been fully evaluated. One hundred and seven TcB measurements were obtained from 82 Japanese newborns ≥35 weeks' gestational age within 2 weeks after birth. Measurements were taken at the scaphoid fossa, conchal cavity, and lobe of the ear using BiliCare. BiliCare TcB were compared with total serum bilirubin (TB) and TcB obtained using another bilirubinometer (JM-105™). Transcutaneous bilirubin measured at all three sites significantly correlated with TB (r = 0.91, 0.93, and 0.93 at the scaphoid fossa, conchal cavity, and lobe, respectively). The mean differences were 0.1, -0.3, and 3.6 at the scaphoid fossa, conchal cavity, and lobe, respectively. BiliCare TcB at the scaphoid fossa significantly correlated with that using the JM-105 (r = 0.91). The mean difference was 0.0. BiliCare, however, produced a significantly higher and lower TcB than the JM-105 for TB bilirubin measurements taken at the scaphoid fossa or conchal cavity using BiliCare were more reliable than those at the earlobe. BiliCare TcB differed from those of the JM-105, for TB <7 or ≥15 mg/dL. © 2017 Japan Pediatric Society.

  15. Effect of low frequency transcutaneous magnetic stimulation on sensory and motor transmission.

    Science.gov (United States)

    Leung, Albert; Shukla, Shivshil; Lee, Jacquelyn; Metzger-Smith, Valerie; He, Yifan; Chen, Jeffrey; Golshan, Shahrokh

    2015-09-01

    Peripheral nerve injury diminishes fast conducting large myelinated afferent fibers transmission but enhances smaller pain transmitting fibers firing. This aberrant afferent neuronal behavior contributes to development of chronic post-traumatic peripheral neuropathic pain (PTP-NP). Non-invasive dynamic magnetic flux stimulation has been implicated in treating PTP-NP, a condition currently not adequately addressed by other therapies including transcutaneous electrical nerve stimulation (TENS). The current study assessed the effect of low frequency transcutaneous magnetic stimulation (LFTMS) on peripheral sensory thresholds, nerve conduction properties, and TENS induced fast afferent slowing effect as measured by motor and sensory conduction studies in the ulnar nerve. Results indicated sham LFTMS with TENS (Sham + TENS) significantly (P = 0.02 and 0.007, respectively) reduces sensory conduction velocity (CV) and increases sensory onset latency (OL), and motor peak latency (PL) whereas, real LFTMS with TENS (Real + TENS) reverses effects of TENS on sensory CV and OL, and significantly (P = 0.036) increases the sensory PL. LFTMS alone significantly (P sensory PL and onset-to-peak latency. LFTMS appears to reverse TENS slowing effect on fast conducting fibers and casts a selective peripheral modulatory effect on slow conducting pain afferent fibers. © 2015 Wiley Periodicals, Inc.

  16. Development of novel double-decker microneedle patches for transcutaneous vaccine delivery.

    Science.gov (United States)

    Ono, Akihiko; Azukizawa, Hiroaki; Ito, Sayami; Nakamura, Yuki; Asada, Hideo; Quan, Ying-Shu; Kamiyama, Fumio; Katayama, Ichiro; Hirobe, Sachiko; Okada, Naoki

    2017-10-30

    Microneedle (MN) patches have great potential as transcutaneous vaccine delivery devices because MNs can effectively deliver vaccine antigen into the skin through the micropores formed in the stratum corneum by low-invasive and painless skin puncturing. This study aims to develop novel double-decker MN patches which have not only high safety and efficacy but also broad applicability to various vaccine antigens. We developed two types of MN patches (PGA-MN and Nylon-MN) that are made from polyglycolic acid and Nylon-6. In pre-clinical studies, both MN patches could demonstrably deliver antigens into resected human dermal tissue, prolong antigen deposition and increase antigen-specific IgG levels after vaccination compared with conventional injections. We demonstrated both MN patches could be safely applied to human skin because no broken MNs or significant skin irritation were observed after applications in the clinical research. PGA-MN was suggested to be superior to Nylon-MN regarding human skin puncturability based on measurements of transepidermal water loss and needle failure force. A high content of tetravalent influenza hemagglutinin antigens loaded on PGA-MN could stably maintain HA titers at 35°C for 1year. Overall, double-decker MN patches can reliably and safely puncture human skin and are promising as effective transcutaneous vaccine delivery devices. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Randomized clinical trial of intracutaneously versus transcutaneously sutured ileostomy to prevent stoma-related complications (ISI trial)

    NARCIS (Netherlands)

    Sier, M. F.; Wisselink, D. D.; Ubbink, D. T.; Oostenbroek, R. J.; Veldink, G. J.; Lamme, B.; van Duijvendijk, P.; van Geloven, A. A. W.; Eijsbouts, Q. A. J.; Bemelman, W. A.; van Grevenstein, M. U.; Veltkamp, S. C.; Tolenaar, P. L.; van de Laar, A. W. J. M.; Slooter, G. D.; Sonneveld, D. J. A.

    2018-01-01

    Ileostomy construction is a common procedure but can be associated with morbidity. The stoma is commonly secured to the skin using transcutaneous sutures. It is hypothesized that intracutaneous sutures result in a tighter adherence of the peristomal skin to the stoma plate to prevent faecal leakage.

  18. Effect of Transcutaneous Electrical Nerve Stimulation on Sensation Thresholds in Patients with Painful Diabetic Neuropathy: An Observational Study

    Science.gov (United States)

    Moharic, Metka

    2010-01-01

    Transcutaneous electrical nerve stimulation (TENS) is one of the therapies for painful neuropathy. Its analgesic mechanisms probably involve the gate control theory, the physiological block and the endogenous pain inhibitory system. The aim of the study was to determine whether TENS improves small fibre function diminished because of painful…

  19. Effects of transcutaneous electrical nerve stimulation (TENS) on self-efficacy and mood in elderly with mild cognitive impairment

    NARCIS (Netherlands)

    Luijpen, Marijn W.; Swaab, Dick F.; Sergeant, Joseph A.; Scherder, Erik J. A.

    2004-01-01

    In previous studies, transcutaneous electrical nerve stimulation (TENS) has been applied to patients with either Alzheimer's disease (AD) or incipient dementia, resulting in an enhancement in memory and verbal fluency. Moreover, affective behavior was shown to improve. Based on the positive effects

  20. Can We "Predict" Long-Term Outcome for Ambulatory Transcutaneous Electrical Nerve Stimulation in Patients with Chronic Pain?

    NARCIS (Netherlands)

    Koke, A.J.; Smeets, R.J.E.M.; Perez, R.S.G.M.; Kessels, A.; Winkens, B.; van Kleef, M.; Patijn, J.

    2015-01-01

    Background: Evidence for effectiveness of transcutaneous electrical nerve stimulation (TENS) is still inconclusive. As heterogeneity of chronic pain patients might be an important factor for this lack of efficacy, identifying factors for a successful long-term outcome is of great importance.

  1. Transcutaneous Electrical Nerve Stimulation as an Additional Treatment for Women Suffering from Therapy-Resistant Provoked Vestibulodynia : A Feasibility Study

    NARCIS (Netherlands)

    Vallinga, Marleen S.; Spoelstra, Symen K.; Hemel, Inge L. M.; van de Wiel, Harry B. M.; Schultz, Willibrord C. M. Weijnnar

    IntroductionThe current approach to women with provoked vestibulodynia (PVD) comprises a multidimensional, multidisciplinary therapeutic protocol. As PVD is considered to be a chronic pain disorder, transcutaneous electrical nerve stimulation (TENS) can be used as an additional therapy for women

  2. Direct and Indirect Benefits Reported by Users of Transcutaneous Electrical Nerve Stimulation for Chronic Musculoskeletal Pain: Qualitative Exploration Using Patient Interviews.

    Science.gov (United States)

    Gladwell, Peter William; Badlan, Kathryn; Cramp, Fiona; Palmer, Shea

    2015-11-01

    There is no consensus regarding the effectiveness of transcutaneous electrical nerve stimulation (TENS) for management of chronic musculoskeletal pain or chronic low back pain. A recent review of previous trial methodology identified significant problems with low treatment fidelity. There is little information available to guide selection of patient-reported outcome measures appropriate for TENS evaluation. The purpose of this study was to explore the experiences of patients at a secondary care pain clinic who successfully used TENS to help manage chronic musculoskeletal pain. These key informants were selected because they had the potential to generate knowledge that could inform research design and clinical practice. A qualitative method using individual semistructured interviews with open questions was selected for its capacity to generate rich data. A mini focus group informed the development of a discussion guide for semistructured interviews with 9 patients (6 women, 3 men). Thematic analysis was used as the primary data analysis method, and this analysis was enhanced by a case-level analysis of the context and processes of TENS use of each individual. Data analysis indicated that distraction from pain and a reduction in the sensations associated with muscle tension or spasm should be considered as separate outcomes from pain relief. These direct benefits led to a wide range of indirect benefits dependent on patient decision making, including medication reduction, enhanced function, psychological benefits, and enhanced ability to rest. The findings indicate that evaluating TENS using a unidimensional pain scale is likely to overlook potential benefits. The complex pattern of TENS usage, as well as multiple direct and indirect outcomes, indicates that TENS could be considered as a complex intervention. © 2015 American Physical Therapy Association.

  3. Dynamical modeling of surface tension

    International Nuclear Information System (INIS)

    Brackbill, J.U.; Kothe, D.B.

    1996-01-01

    In a recent review it is said that free-surface flows ''represent some of the difficult remaining challenges in computational fluid dynamics''. There has been progress with the development of new approaches to treating interfaces, such as the level-set method and the improvement of older methods such as the VOF method. A common theme of many of the new developments has been the regularization of discontinuities at the interface. One example of this approach is the continuum surface force (CSF) formulation for surface tension, which replaces the surface stress given by Laplace's equation by an equivalent volume force. Here, we describe how CSF might be made more useful. Specifically, we consider a derivation of the CSF equations from a minimization of surface energy as outlined by Jacqmin. This reformulation suggests that if one eliminates the computation of curvature in terms of a unit normal vector, parasitic currents may be eliminated For this reformulation to work, it is necessary that transition region thickness be controlled. Various means for this, in addition to the one discussed by Jacqmin are discussed

  4. Bilateral tension pneumothorax after acupuncture.

    Science.gov (United States)

    Mohammad, Nurashikin

    2018-04-19

    Acupuncture is an ancient complementary medicine which is currently used worldwide. Many serious adverse events have been reported which include a spectrum of mild-to-fatal complications. However, the level of awareness with regard to complications is still low both to physicians and patients. We report a 63-year-old who presented with acute shortness of breath 2 hours after having had acupuncture. On examination, there was absent breath sound heard on the left lung and slightly reduced breath sound on the right lung. She had type 1 respiratory failure. Urgent chest radiograph confirmed bilateral pneumothorax which was more severe on the left with tension pneumothorax and mediastinal shift. Chest tubes were inserted bilaterally after failed needle aspiration attempts. Subsequently, the pneumothoraces resolved, and she was discharged well. The bilateral pneumothoraces caused by acupuncture were curable but could have been potentially fatal if diagnosis was delayed. This case report adds to the limited current literature on the complications of acupuncture leading to bilateral pneumothoraces. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. Gastrothorax or tension pneumothorax: A diagnostic dilemma

    Directory of Open Access Journals (Sweden)

    Singh Sarvesh

    2011-01-01

    Full Text Available Gastrothorax, a rare complication following thoracoabdominal aortic aneurysm repair, is reported. The clinical features of a gastrothorax and tension pneumothorax are similar and thus, a gastrothorax can masquerade as a tension pneumothorax. The diagnosis is made by a high level of clinical suspicion, chest X-ray shows a distended stomach with air fluid levels and a computerised tomography is useful in assessing the diaphragm and establishing the positions of the various intra-abdominal organs. Also, the risk of an intercostal drainage tube placement and the role of nasogastric tube in avoiding the development of a tension gastrothorax is highlighted.

  6. Exploring the oxygen challenge test as a microcirculation evaluation model

    Directory of Open Access Journals (Sweden)

    Hugo Ferreira

    2013-12-01

    Full Text Available Cutaneous microcirculation has emerged in recent years as a practical accessible subject for the study of peripheral circulation. Non-invasive techniques such as Laser Doppler Flowmetry (LDF, skin Evaporimetry and Transcutaneous Gasimetry in association with provocation tests, render cutaneous circulation a very attractive research model. This study was applied to a group of healthy young female volunteers, (n = 8, (21,6 ± 2,6 years old breathing a 100 % oxygen atmosphere for 10 minutes. This test allowed us to evaluate the circulatory response in the lower limb microcirculation. Measurement techniques included local blood flow by LDF, Transcutaneous (tc pO2 partial pressure and Transepidermal Water Loss (TEWL by Evaporimetry. Data analysis revels that tc-pO2 and LDF changed significantly during the test. A reciprocal evolution profile was registered in LDF and TEWL, which seems to support previous data that changes in local blood flow may influence the epidermal “barrier” function. This model seems suitable to characterize the lower limb microcirculation.

  7. Capillary-oxygenation-level-dependent near-infrared spectrometry in frontal lobe of humans

    NARCIS (Netherlands)

    Rasmussen, Peter; Dawson, Ellen A.; Nybo, Lars; van Lieshout, Johannes J.; Secher, Niels H.; Gjedde, Albert

    2007-01-01

    Brain function requires oxygen and maintenance of brain capillary oxygenation is important. We evaluated how faithfully frontal lobe near-infrared spectroscopy (NIRS) follows haemoglobin saturation (SCap) and how calculated mitochondrial oxygen tension (PMitoO2) influences motor performance. Twelve

  8. Radiosensitizers and the oxygen effects in mammalian cells

    International Nuclear Information System (INIS)

    Millar, B.C.; Fielden, E.M.; Steele, J.J.

    1979-01-01

    The survival curves for Chinese Hamster cells irradiated under various oxygen tensions have been determined. The variation in OER with oxygen concentration shows two distinct components. Between 1.4 and 7.0 μM the OER is constant with a value of 1.9. Experiments with nitroaromatic radiosensitizers in combination with low concentrations of oxygen show that they can all mimic the 'low concentration' oxygen effect. Of the compounds tested only misonidazole can apparently mimic the 'high concentration' oxygen effect although the full OER cannot be obtained with the authors cell line because of toxicity by the sensitizer. (Auth.)

  9. Managing Tensions And Forging Creative Synergies Between ...

    African Journals Online (AJOL)

    Managing Tensions And Forging Creative Synergies Between Indigenous And Modern Settlement Planning Concepts And Practices: Lessons For The Design And Planning For Sustainable Settlements And Built-Forms In Southern Africa.

  10. Tension perturbations of black brane spacetimes

    International Nuclear Information System (INIS)

    Traschen, Jennie; Fox, Daniel

    2004-01-01

    We consider black brane spacetimes that have at least one spatial translation Killing field that is tangent to the brane. A new parameter, the tension of a spacetime, is defined. The tension parameter is associated with spatial translations in much the same way that the ADM mass is associated with the time translation Killing field. In this work, we explore the implications of the spatial translation symmetry for small perturbations around a background black brane. For static-charged black branes we derive a law which relates the tension perturbation to the surface gravity times the change in the horizon area, plus terms that involve variations in the charges and currents. We find that as a black brane evaporates the tension decreases. We also give a simple derivation of a first law for black brane spacetimes. These constructions hold when the background stress-energy is governed by a Hamiltonian, and the results include arbitrary perturbative stress-energy sources

  11. Notch effects in uniaxial tension specimens

    International Nuclear Information System (INIS)

    Delph, T.J.

    1979-03-01

    Results of a literature survey on the effect of notches on the time-dependent failure of uniaxial tension specimens at elevated temperatures are presented. Particular attention is paid to the failure of notched specimens containing weldments

  12. Tension waves in tethered satellite cables

    Science.gov (United States)

    Lallman, F. J.

    1984-01-01

    A one-degree-of-freedom simulation of the Tethered Satellite System (TSS) was programmed using a distributed system model of the tether based on the one-dimensional wave equation. This model represents the time varying tension profile along the tether as the sum of two traveling waves of tension moving in opposite directions. A control loop was devised which combines a deployment rate command with the measured tension at the deployer to produce a smooth, stable rate of deployment of the subsatellite. Simulation results show a buildup of periodic bursts of high frequency oscillation in tension. This report covers the mathematical modelling and simulation results and explains the reason for the observed oscillations. The design of a possible vibration damping device is discussed.

  13. Tension Hydrothorax Related to Disseminated Endometriosis

    Directory of Open Access Journals (Sweden)

    AnnaKate Deal, MD

    2016-01-01

    Full Text Available We present the case of a 34-year-old woman presenting to the emergency department (ED with dyspnea, cough, and fever. She was found to have a tension hydrothorax and was treated with ultrasound-guided thoracentesis in the ED. Subsequent inpatient evaluation showed the patient had disseminated endometriosis. Tension hydrothorax has not been previously described in the literature as a complication of this disease.

  14. Density and surface tension of ionic liquids.

    Science.gov (United States)

    Kolbeck, C; Lehmann, J; Lovelock, K R J; Cremer, T; Paape, N; Wasserscheid, P; Fröba, A P; Maier, F; Steinrück, H-P

    2010-12-30

    We measured the density and surface tension of 9 bis[(trifluoromethyl)sulfonyl]imide ([Tf(2)N](-))-based and 12 1-methyl-3-octylimidazolium ([C(8)C(1)Im](+))-based ionic liquids (ILs) with the vibrating tube and the pendant drop method, respectively. This comprehensive set of ILs was chosen to probe the influence of the cations and anions on density and surface tension. When the alkyl chain length in the [C(n)C(1)Im][Tf(2)N] series (n = 1, 2, 4, 6, 8, 10, 12) is increased, a decrease in density is observed. The surface tension initially also decreases but reaches a plateau for alkyl chain lengths greater than n = 8. Functionalizing the alkyl chains with ethylene glycol groups results in a higher density as well as a higher surface tension. For the dependence of density and surface tension on the chemical nature of the anion, relations are only found for subgroups of the studied ILs. Density and surface tension values are discussed with respect to intermolecular interactions and surface composition as determined by angle-resolved X-ray photoelectron spectroscopy (ARXPS). The absence of nonvolatile surface-active contaminants was proven by ARXPS.

  15. Clinical experience with TENS and TENS combined with nitrous oxide-oxygen. Report of 371 patients.

    OpenAIRE

    Quarnstrom, F. C.; Milgrom, P.

    1989-01-01

    Transcutaneous electrical nerve stimulation (TENS) alone or TENS combined with nitrous oxide-oxygen (N2O) was administered for restorative dentistry without local anesthesia to 371 adult patients. A total of 55% of TENS alone and 84% of TENS/N2O visits were rated successful. A total of 53% of TENS alone and 82% of TENS/N2O patients reported slight or no pain. In multivariable analyses, pain reports were related to the anesthesia technique and patient fear and unrelated to sex, race, age, toot...

  16. Electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter system*

    Science.gov (United States)

    Zan, Peng; Yang, Bang-hua; Shao, Yong; Yan, Guo-zheng; Liu, Hua

    2010-01-01

    This paper reports on the electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter. The coupling coils and human tissues, including the skin, fat, muscle, liver, and blood, were considered. Specific absorption rate (SAR) and current density were analyzed by a finite-length solenoid model. First, SAR and current density as a function of frequency (10–107 Hz) for an emission current of 1.5 A were calculated under different tissue thickness. Then relations between SAR, current density, and five types of tissues under each frequency were deduced. As a result, both the SAR and current density were below the basic restrictions of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The results show that the analysis of these data is very important for developing the artificial anal sphincter system. PMID:21121071

  17. RehaMovePro: A versatile mobile stimulation system for transcutaneous FES applications

    Directory of Open Access Journals (Sweden)

    Markus Valtin

    2016-06-01

    Full Text Available Functional Electrical Stimulation is a commonly used method in clinical rehabilitation and research to trigger useful muscle contractions by electrical stimuli. In this work, we present a stimulation system for transcutaneous electrical stimulation that gives extensive control over the stimulation waveform and the stimulation timing. The system supports electrode arrays, which have been suggested to achieve better selectivity and to simplify electrode placement. Electromyography (EMG measurements are obtained from the active stimulation electrodes (between the stimulation pulses or from separate surface EMG electrodes. The modular design enables the implementation of sophisticated stimulation control systems including external triggers or wireless sensors. This is demonstrated by the standalone implementation of a feedback-controlled drop foot neuroprosthesis, which uses a wireless inertial sensor for real-time gait phase detection and foot orientation measurement.

  18. Subcuticular Suture Technique: Alternative to Frost Suture to Prevent Ectropion After Transcutaneous Incision of Lower Eyelid.

    Science.gov (United States)

    Kudva, Adarsh; Kamath, Abhay; Cariappa, K M; Gadicherla, Srikanth; Dhara, B Vasantha

    2017-12-01

    An ectropion is a complication that can arise from reconstruction in the infraorbital region. Often, this complication occurs despite proper positioning of the lower lid at the time of closure. Various transcutaneous approaches to orbit skeleton have investigated in view of complication arising from them. A subtarsal approach with a postoperative Frost suture gives an advantage to reduce the occurrence of ectropion especially after treatment of orbital floor fractures. This case describes a method of subcuticular suturing technique for subtarsal incision of lower lid which can be used to support the lid during healing period, thus decreasing the rate of ectropion. The technique described here is an alterative method for frost suturing with certain advantages.

  19. Design and Evaluation on the Mobile Application of Transcutaneous Electrical Nerve Stimulation (TENS).

    Science.gov (United States)

    Cheng, Ching-Lung; Lee, Li-Hui; Cheng, Yu-Ting

    2017-01-01

    This study aims to design a transcutaneous electrical nerve stimulation Application (TENS App) according to the suggestions from potential users. To the best of our knowledge, this is the first App including meridian and acupoints for TENS. After its development, there are eight participants recruited for evaluating the usability. Despite two out of eight users reporting that the typical TENS system requires lower cost and has better functionality than TENS App, the results show that almost seventy percent of participants have a better perception of TENS App on price, functionality, convenience, operational ability, and quality. However, participants still reported concerns about the safety issue of adopting TENS App. Therefore, for people who are the first time or unfamiliar with TENS App, instructions from occupational or physical therapists are recommended. We conclude that by using TENS App, users can not only use the portable electrotherapy devices at anyplace, but also reduce their outpatient visits.

  20. Use of electroacupuncture and transcutaneous electrical acupoint stimulation in reproductive medicine: a group consensus.

    Science.gov (United States)

    Qu, Fan; Li, Rong; Sun, Wei; Lin, Ge; Zhang, Rong; Yang, Jing; Tian, Li; Xing, Guo-Gang; Jiang, Hui; Gong, Fei; Liang, Xiao-Yan; Meng, Yan; Liu, Jia-Yin; Zhou, Li-Ying; Wang, Shu-Yu; Wu, Yan; He, Yi-Jing; Ye, Jia-Yu; Han, Song-Ping; Han, Ji-Sheng

    With the rapid development of assisted reproductive technology, various reproductive disorders have been effectively addressed. Acupuncture-like therapies, including electroacupuncture (EA) and transcutaneous electrical acupoint stimulation (TEAS), become more popular world-wide. Increasing evidence has demonstrated that EA and TEAS are effective in treating gynecological disorders, especially infertility. This present paper describes how to select acupoints for the treatment of infertility from the view of theories of traditional Chinese medicine and how to determine critical parameters of electric pulses of EA/TEAS based on results from animal and clinical studies. It summarizes the principles of clinical application of EA/TEAS in treating various kinds of reproductive disorders, such as polycystic ovary syndrome (PCOS), pain induced by oocyte retrieval, diminished ovarian reserve, embryo transfer, and oligospermia/ asthenospermia. The possible underlying mechanisms mediating the therapeutic effects of EA/TEAS in reproductive medicine are also examined.

  1. 3D splint prototype system for applications in muscular rehab by transcutaneous electrical nerve stimulation (TENS)

    Science.gov (United States)

    Saldaña-Martínez, M. I.; Guzmán-González, J. V.; Barajas-González, O. G.; Guzman-Ramos, V.; García-Garza, A. K.; González-García, R. B.; García-Ramírez, M. A.

    2017-03-01

    It is quite common that patients with ligamentous ruptures, tendonitis, tenosynovitis or sprains are foreseen the use of ad hoc splints for a swift recovery. In this paper, we propose a rehabilitation split that is focused on upper-limb injuries. By considering that upper-limb patient shows a set of different characteristics, our proposal personalizes and prints the splint custom made though a digital model that is generated by a 3D commercial scanner. To fabricate the 3D scanned model the Stereolithography material (SLA) is considered due to the properties that this material offers. In order to complement the recovery process, an electronic system is implemented within the splint design. This system generates a set of pulses for a fix period of time that focuses mainly on a certain group of muscles to allow a fast recovery process known as Transcutaneous Electrical Nerve Stimulation Principle (TENS).

  2. Toward a general psychological model of tension and suspense.

    Science.gov (United States)

    Lehne, Moritz; Koelsch, Stefan

    2015-01-01

    Tension and suspense are powerful emotional experiences that occur in a wide variety of contexts (e.g., in music, film, literature, and everyday life). The omnipresence of tension and suspense suggests that they build on very basic cognitive and affective mechanisms. However, the psychological underpinnings of tension experiences remain largely unexplained, and tension and suspense are rarely discussed from a general, domain-independent perspective. In this paper, we argue that tension experiences in different contexts (e.g., musical tension or suspense in a movie) build on the same underlying psychological processes. We discuss key components of tension experiences and propose a domain-independent model of tension and suspense. According to this model, tension experiences originate from states of conflict, instability, dissonance, or uncertainty that trigger predictive processes directed at future events of emotional significance. We also discuss possible neural mechanisms underlying tension and suspense. The model provides a theoretical framework that can inform future empirical research on tension phenomena.

  3. Noninvasive lifting of arm, thigh, and knee skin with transcutaneous intense focused ultrasound.

    Science.gov (United States)

    Alster, Tina S; Tanzi, Elizabeth L

    2012-05-01

    Transcutaneous intense focused ultrasound is a novel Food and Drug Administration-approved technology for noninvasive skin tightening of the face and neck. No studies have reported on its safety and effectiveness on nonfacial areas. Eighteen paired areas (6 each) on the upper arms, medial thighs, and extensor knees were randomly treated with two different transducers (4.0 MHz, 4.5-mm focal depth and 7.0 MHz, 3.0-mm focal depth). One side was randomly assigned to receive a single pass (single plane) of microthermal coagulation zones over the involved area with the 4.0 MHz, 4.5-mm-depth transducer, and the contralateral side was assigned to receive consecutive single passes (dual plane) using both transducers (4.0 MHz, 4.5-mm depth followed by 7.0 MHz, 3.0-mm depth). Two independent masked assessors determined clinical improvement scores using comparative standardized photographs obtained at baseline and 3 and 6 months after treatment. Subjective assessments of clinical improvement and side effects of treatment were obtained. Global assessment scores revealed significant improvement in all treated areas, with the upper arms and knees demonstrating more skin lifting and tightening than the thighs. Areas receiving dual-plane treatment had slightly better clinical scores than those receiving single-plane treatment in all three sites. Clinical scores from single-plane and dual-plane treated areas continued to improve between 3 and 6 months after treatment. Side effects were mild and transient and included erythema, warmth, and skin tenderness. Rare focal bruising was noted in two patients on the upper arms that resolved within 7 days. No other side effects were reported or observed. Transcutaneous intense focused ultrasound can be safely and effectively used to improve the clinical appearance (texture and contour) of the upper arms, extensor knees, and medial thighs. © 2012 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

  4. Body Position Influences Which Neural Structures Are Recruited by Lumbar Transcutaneous Spinal Cord Stimulation.

    Directory of Open Access Journals (Sweden)

    Simon M Danner

    Full Text Available Transcutaneous stimulation of the human lumbosacral spinal cord is used to evoke spinal reflexes and to neuromodulate altered sensorimotor function following spinal cord injury. Both applications require the reliable stimulation of afferent posterior root fibers. Yet under certain circumstances, efferent anterior root fibers can be co-activated. We hypothesized that body position influences the preferential stimulation of sensory or motor fibers. Stimulus-triggered responses to transcutaneous spinal cord stimulation were recorded using surface-electromyography from quadriceps, hamstrings, tibialis anterior, and triceps surae muscles in 10 individuals with intact nervous systems in the supine, standing and prone positions. Single and paired (30-ms inter-stimulus intervals biphasic stimulation pulses were applied through surface electrodes placed on the skin between the T11 and T12 inter-spinous processes referenced to electrodes on the abdomen. The paired stimulation was applied to evaluate the origin of the evoked electromyographic response; trans-synaptic responses would be suppressed whereas direct efferent responses would almost retain their amplitude. We found that responses to the second stimulus were decreased to 14%±5% of the amplitude of the response to the initial pulse in the supine position across muscles, to 30%±5% in the standing, and to only 80%±5% in the prone position. Response thresholds were lowest during standing and highest in the prone position and response amplitudes were largest in the supine and smallest in the prone position. The responses obtained in the supine and standing positions likely resulted from selective stimulation of sensory fibers while concomitant motor-fiber stimulation occurred in the prone position. We assume that changes of root-fiber paths within the generated electric field when in the prone position increase the stimulation thresholds of posterior above those of anterior root fibers. Thus, we

  5. Electrical characteristic of the titanium mesh electrode for transcutaneous intrabody communication to monitor implantable artificial organs.

    Science.gov (United States)

    Okamoto, Eiji; Kikuchi, Sakiko; Mitamura, Yoshinori

    2016-09-01

    We have developed a tissue-inducing electrode using titanium mesh to obtain mechanically and electrically stable contact with the tissue for a new transcutaneous communication system using the human body as a conductive medium. In this study, we investigated the electrical properties of the titanium mesh electrode by measuring electrode-tissue interface resistance in vivo. The titanium mesh electrode (Hi-Lex Co., Zellez, Hyogo, Japan) consisted of titanium fibers (diameter of 50 μm), and it has an average pore size of 200 μm and 87 % porosity. The titanium mesh electrode has a diameter of 5 mm and thickness of 1.5 mm. Three titanium mesh electrodes were implanted separately into the dorsal region of the rat. We measured the electrode-electrode impedance using an LCR meter for 12 weeks, and we calculated the tissue resistivity and electrode-tissue interface resistance. The electrode-tissue interface resistance of the titanium mesh electrode decreased slightly until the third POD and then continuously increased to 75 Ω. The electrode-tissue interface resistance of the titanium mesh electrode is stable and it has lower electrode-tissue interface resistance than that of a titanium disk electrode. The extracted titanium mesh electrode after 12 weeks implantation was fixed in 10 % buffered formalin solution and stained with hematoxylin-eosin. Light microscopic observation showed that the titanium mesh electrode was filled with connective tissue, inflammatory cells and fibroblasts with some capillaries in the pores of the titanium mesh. The results indicate that the titanium mesh electrode is a promising electrode for the new transcutaneous communication system.

  6. Feasibility study of Transcutaneous Electrical Nerve Stimulation (TENS) for cancer bone pain.

    Science.gov (United States)

    Bennett, Michael I; Johnson, Mark I; Brown, Sarah R; Radford, Helen; Brown, Julia M; Searle, Robert D

    2010-04-01

    This multicenter study assessed the feasibility of conducting a phase III trial of transcutaneous electrical nerve stimulation (TENS) in patients with cancer bone pain recruited from palliative care services. Eligible patients received active and placebo TENS for 1 hour at site of pain in a randomized crossover design; median interval between applications 3 days. Responses assessed at 30 and 60 minutes included numerical and verbal ratings of pain at rest and on movement, and pain relief. Recruitment, tolerability, adverse events, and effectiveness of blinding were also evaluated. Twenty-four patients were randomised and 19 completed both applications. The intervention was well tolerated. Five patients withdrew: 3 due to deteriorating performance status, and 2 due to increased pain (1 each following active and placebo TENS). Confidence interval estimation around the differences in outcomes between active and placebo TENS suggests that TENS has the potential to decrease pain on movement more than pain on rest. Nine patients did not consider that a placebo was used; the remaining 10 correctly identified placebo TENS. Feasibility studies are important in palliative care prior to undertaking clinical trials. Our findings suggest that further work is required on recruitment strategies and refining the control arm before evaluating TENS in cancer bone pain. Cancer bone pain is common and severe, and partly mediated by hyperexcitability. Animal studies suggest that Transcutaneous Electrical Nerve Stimulation can reduce hyperalgesia. This study examined the feasibility of evaluating TENS in patients with cancer bone pain in order to optimize methods before a phase III trial. Copyright 2010 American Pain Society. Published by Elsevier Inc. All rights reserved.

  7. Transcutaneous ultrasound for evaluation of vocal fold movement in patients with thyroid disease

    International Nuclear Information System (INIS)

    Wang, Cheng-Ping; Chen, Tseng-Cheng; Yang, Tsung-Lin; Chen, Chun-Nan; Lin, Chin-Fon; Lou, Pei-Jen; Hu, Ya-Ling; Shieh, Ming-Jium; Hsieh, Fon-Jou

    2012-01-01

    Background: Preoperative evaluation of recurrent laryngeal nerve function is important in the context of thyroid surgery. Transcutaneous ultrasound may be useful to visualize vocal fold movement when evaluating thyroid disease. Methods: A 7–18 MHz linear array transducer was placed transversely on the midline of the thyroid cartilage at the anterior neck of patients with thyroid disease. The gray-scale technique was used, with the scan setting for the thyroid gland. Results: Between August 2008 and March 2010, 705 patients, including 672 patients with normal vocal fold movement and 33 patients with vocal fold paralysis were enrolled. They included 159 male and 546 female patients. Their ages ranged from 10 to 88 years. Vocal fold movement could be seen by ultrasound in 614 (87%) patients, including 589 (88%) patients with normal vocal fold movement and 25 (76%) patients with vocal fold paralysis (p = 0.06). The mean age of patients with visible and invisible vocal fold movement was 46.6 and 57.9 years old, respectively (p = 0.001). Ultrasound was able to see vocal fold movement in 533 (98%) female patients but only in 81 (51%) male patients (p = 0.001). Among the patients with vocal fold paralysis, ultrasound revealed palsied vocal folds in 17 of 18 (94%) female patients but in only 8 of 15 (53%) male patients (p = 0.01). Conclusion: Transcutaneous ultrasound represents an alternative tool to evaluate vocal fold movement for more than 85% of patients with thyroid disease, including more than 90% of female patients and about half of male patients.

  8. Measurement of brain oxygenation changes using dynamic T1-weighted imaging

    DEFF Research Database (Denmark)

    Haddock, Bryan; Larsson, Henrik B W; Hansen, Adam E

    2013-01-01

    Magnetic resonance imaging (MRI) has proven useful in evaluating oxygenation in several types of tissue and blood. This study evaluates brain tissue oxygenation changes between normoxia and hyperoxia in healthy subjects using dynamic T1 and T2*-weighted imaging sequences. The change in FiO2 induced...... by hyperoxia caused a significant decrease in T1. A model to determine changes in tissue oxygen tension from the T1-weighted MRI signal is presented based on previous findings that T1 is sensitive to oxygen tension whereas T2* is sensitive to blood saturation. The two sequences produce results with different...... regional and temporal dynamics. These differences combined with results from simulations of the T1 signal intensities, indicate an increase in extravascular oxygen tension during hyperoxia. This study concludes that T1 and T2* responses to FiO2 serve as independent biomarkers of oxygen physiology...

  9. A novel approach to pipeline tensioner modeling

    Energy Technology Data Exchange (ETDEWEB)

    O' Grady, Robert; Ilie, Daniel; Lane, Michael [MCS Software Division, Galway (Ireland)

    2009-07-01

    As subsea pipeline developments continue to move into deep and ultra-deep water locations, there is an increasing need for the accurate prediction of expected pipeline fatigue life. A significant factor that must be considered as part of this process is the fatigue damage sustained by the pipeline during installation. The magnitude of this installation-related damage is governed by a number of different agents, one of which is the dynamic behavior of the tensioner systems during pipe-laying operations. There are a variety of traditional finite element methods for representing dynamic tensioner behavior. These existing methods, while basic in nature, have been proven to provide adequate forecasts in terms of the dynamic variation in typical installation parameters such as top tension and sagbend/overbend strain. However due to the simplicity of these current approaches, some of them tend to over-estimate the frequency of tensioner pay out/in under dynamic loading. This excessive level of pay out/in motion results in the prediction of additional stress cycles at certain roller beds, which in turn leads to the prediction of unrealistic fatigue damage to the pipeline. This unwarranted fatigue damage then equates to an over-conservative value for the accumulated damage experienced by a pipeline weld during installation, and so leads to a reduction in the estimated fatigue life for the pipeline. This paper describes a novel approach to tensioner modeling which allows for greater control over the velocity of dynamic tensioner pay out/in and so provides a more accurate estimation of fatigue damage experienced by the pipeline during installation. The paper reports on a case study, as outlined in the proceeding section, in which a comparison is made between results from this new tensioner model and from a more conventional approach. The comparison considers typical installation parameters as well as an in-depth look at the predicted fatigue damage for the two methods

  10. Emergency percutaneous needle decompression for tension pneumoperitoneum

    Directory of Open Access Journals (Sweden)

    Körner Markus

    2011-05-01

    Full Text Available Abstract Background Tension pneumoperitoneum as a complication of iatrogenic bowel perforation during endoscopy is a dramatic condition in which intraperitoneal air under pressure causes hemodynamic and ventilatory compromise. Like tension pneumothorax, urgent intervention is required. Immediate surgical decompression though is not always possible due to the limitations of the preclinical management and sometimes to capacity constraints of medical staff and equipment in the clinic. Methods This is a retrospective analysis of cases of pneumoperitoneum and tension pneumoperitoneum due to iatrogenic bowel perforation. All patients admitted to our surgical department between January 2005 and October 2010 were included. Tension pneumoperitoneum was diagnosed in those patients presenting signs of hemodynamic and ventilatory compromise in addition to abdominal distension. Results Between January 2005 and October 2010 eleven patients with iatrogenic bowel perforation were admitted to our surgical department. The mean time between perforation and admission was 36 ± 14 hrs (range 30 min - 130 hrs, between ER admission and begin of the operation 3 hrs and 15 min ± 47 min (range 60 min - 9 hrs. Three out of eleven patients had clinical signs of tension pneumoperitoneum. In those patients emergency percutaneous needle decompression was performed with a 16G venous catheter. This improved significantly the patients' condition (stabilization of vital signs, reducing jugular vein congestion, bridging the time to the start of the operation. Conclusions Hemodynamical and respiratory compromise in addition to abdominal distension shortly after endoscopy are strongly suggestive of tension pneumoperitoneum due to iatrogenic bowel perforation. This is a rare but life threatening condition and it can be managed in a preclinical and clinical setting with emergency percutaneous needle decompression like tension pneumothorax. Emergency percutaneous decompression is no

  11. Surface tension in soap films: revisiting a classic demonstration

    International Nuclear Information System (INIS)

    Behroozi, F

    2010-01-01

    We revisit a classic demonstration for surface tension in soap films and introduce a more striking variation of it. The demonstration shows how the film, pulling uniformly and normally on a loose string, transforms it into a circular arc under tension. The relationship between the surface tension and the string tension is analysed and presented in a useful graphical form. (letters and comments)

  12. Surface tension in soap films: revisiting a classic demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Behroozi, F [Department of Physics, University of Northern Iowa, Cedar Falls, IA 50614 (United States)], E-mail: behroozi@uni.edu

    2010-01-15

    We revisit a classic demonstration for surface tension in soap films and introduce a more striking variation of it. The demonstration shows how the film, pulling uniformly and normally on a loose string, transforms it into a circular arc under tension. The relationship between the surface tension and the string tension is analysed and presented in a useful graphical form. (letters and comments)

  13. Mentoring Preservice Teachers: Identifying Tensions and Possible Resolutions

    Science.gov (United States)

    Hudson, Peter; Hudson, Sue

    2018-01-01

    Tensions can occur in the mentor-mentee relationship during school-based professional experiences that require problem solving. What are the tensions for mentor teachers in preservice teacher education and how might these tensions be resolved? This qualitative study collected data from 31 high school mentor teachers about tensions experienced with…

  14. Exploratory experimental investigations on post-tensioned structural glass beams

    DEFF Research Database (Denmark)

    Louter, C.; Nielsen, Jens Henrik; Belis, J.

    2013-01-01

    This paper discusses two projects on post-tensioned glass beams, performed at EPFL and DTU, respectively. In these projects small scale glass beams (length of 1.5m and 1m) are post-tensioned by means of steel threaded rods tensioned at the beam ends. The purpose of post-tensioning glass beams...

  15. Acupuncture and transcutaneous electric nerve stimulation in the treatment of pain associated with chronic pancreatitis. A randomized study

    DEFF Research Database (Denmark)

    Ballegaard, Søren; Christophersen, S J; Dawids, Steen

    1985-01-01

    In 23 patients with pancreatitis, daily pain for at least 3 months, and no abuse of alcohol, the pain-relieving effect of electroacupuncture (13 patients) or transcutaneous electric nerve stimulation (TENS) (16 patients) was studied. In two prospective studies with a cross-over design, active acu...... acupuncture was compared with sham acupuncture, and TENS of the segmental points of the pancreas with sham treatment. Neither electroacupuncture nor TENS brought about pain relief that could substitute for or supplement medical treatment....

  16. The effects of Transcutaneous Electrical Nerve Stimulation on postural control in patients with chronic low back pain

    OpenAIRE

    Rojhani-Shirazi, Z; Rezaeian, T

    2015-01-01

    Objective: The effects of transcutaneous electrical nerve stimulation (TENS) on postural control in patients with low back pain which is not well known. This study aimed to evaluate the effects of TENS on postural control in chronic low back pain. Methods: This study was an experimental research design. Twenty-eight patients with chronic LBP (25-45 Y/ O) participated and by using a random allocation, were divided to samples who participated in this study. The mean center of pressure (COP) vel...

  17. Transcutaneous application of carbon dioxide (CO2 induces mitochondrial apoptosis in human malignant fibrous histiocytoma in vivo.

    Directory of Open Access Journals (Sweden)

    Yasuo Onishi

    Full Text Available Mitochondria play an essential role in cellular energy metabolism and apoptosis. Previous studies have demonstrated that decreased mitochondrial biogenesis is associated with cancer progression. In mitochondrial biogenesis, peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α regulates the activities of multiple nuclear receptors and transcription factors involved in mitochondrial proliferation. Previously, we showed that overexpression of PGC-1α leads to mitochondrial proliferation and induces apoptosis in human malignant fibrous histiocytoma (MFH cells in vitro. We also demonstrated that transcutaneous application of carbon dioxide (CO(2 to rat skeletal muscle induces PGC-1α expression and causes an increase in mitochondrial proliferation. In this study, we utilized a murine model of human MFH to determine the effect of transcutaneous CO(2 exposure on PGC-1α expression, mitochondrial proliferation and cellular apoptosis. PGC-1α expression was evaluated by quantitative real-time PCR, while mitochondrial proliferation was assessed by immunofluorescence staining and the relative copy number of mitochondrial DNA (mtDNA was assessed by real-time PCR. Immunofluorescence staining and DNA fragmentation assays were used to examine mitochondrial apoptosis. We also evaluated the expression of mitochondrial apoptosis related proteins, such as caspases, cytochorome c and Bax, by immunoblot analysis. We show that transcutaneous application of CO(2 induces PGC-1α expression, and increases mitochondrial proliferation and apoptosis of tumor cells, significantly reducing tumor volume. Proteins involved in the mitochondrial apoptotic cascade, including caspase 3 and caspase 9, were elevated in CO(2 treated tumors compared to control. We also observed an enrichment of cytochrome c in the cytoplasmic fraction and Bax protein in the mitochondrial fraction of CO(2 treated tumors, highlighting the involvement of mitochondria in apoptosis

  18. Comparison of Audiological Results Between a Transcutaneous and a Percutaneous Bone Conduction Instrument in Conductive Hearing Loss.

    Science.gov (United States)

    Gerdes, Timo; Salcher, Rolf Benedikt; Schwab, Burkard; Lenarz, Thomas; Maier, Hannes

    2016-07-01

    In conductive, mixed hearing losses and single-sided-deafness bone-anchored hearing aids are a well-established treatment. The transcutaneous transmission across the intact skin avoids the percutaneous abutment of a bone-anchored device with the usual risk of infections and requires less care.In this study, the audiological results of the Bonebridge transcutaneous bone conduction implant (MED-EL) are compared to the generally used percutaneous device BP100 (Cochlear Ltd., Sydney, Australia). Ten patients implanted with the transcutaneous hearing implant were compared to 10 matched patients implanted with a percutaneous device. Tests included pure-tone AC and BC thresholds and unaided and aided sound field thresholds. Speech intelligibility was determined in quiet using the Freiburg monosyllable test and in noise with the Oldenburg sentence test (OLSA) in sound field with speech from the front (S0). The subjective benefit was assessed with the Abbreviated Profile of Hearing Aid Benefit. In comparison with the unaided condition there was a significant improvement in aided thresholds, word recognition scores (WRS), and speech reception thresholds (SRT) in noise, measured in sound field, for both devices. The comparison of the two devices revealed a minor but not significant difference in functional gain (Bonebridge: PTA = 27.5 dB [mean]; BAHA: PTA = 26.3 dB [mean]). No significant difference between the two devices was found when comparing the improvement in WRSs and SRTs (Bonebridge: improvement WRS = 80% [median], improvement SRT = 6.5 dB SNR [median]; BAHA: improvement WRS = 77.5% [median], BAHA: improvement SRT = 6.9 dB SNR [median]). Our data show that the transcutaneous bone conduction hearing implant is an audiologically equivalent alternative to percutaneous bone-anchored devices in conductive hearing loss with a minor sensorineural hearing loss component.

  19. Analgesic effectiveness of the association of transcutaneous electrical nerve stimulation and cryotherapy for chronic low back pain

    OpenAIRE

    Abreu,Eliziete Almeida de; Santos,Jean Douglas Moura dos; Ventura,Patrícia Lima

    2011-01-01

    BACKGROUND AND OBJECTIVES: Transcutaneous electrical nerve stimulation (TENS) and cryotherapy are physical therapy resources individually used, since there is the possibility of interaction between TENS and cryotherapy if they are associated. This study aimed at evaluating the analgesic effectiveness of the association or not of TENS and cryotherapy to relieve chronic low back pain. METHOD: Clinical trial involving six chronic low back pain patients distributed in three groups: cryotherapy, T...

  20. Comparison of the OxyMask and Venturi mask in the delivery of supplemental oxygen: Pilot study in oxygen-dependent patients

    Science.gov (United States)

    Beecroft, Jaime M; Hanly, Patrick J

    2006-01-01

    BACKGROUND: The OxyMask (Southmedic Inc, Canada) is a new face mask for oxygen delivery that uses a small ‘diffuser’ to concentrate and direct oxygen toward the mouth and nose. The authors hypothesized that this unique design would enable the OxyMask to deliver oxygen more efficiently than a Venturi mask (Hudson RCI, USA) in patients with chronic hypoxemia. METHODS: Oxygen-dependent patients with chronic, stable respiratory disease were recruited to compare the OxyMask and Venturi mask in a randomized, single-blind, cross-over design. Baseline blood oxygen saturation (SaO2) was established breathing room air, followed in a random order by supplemental oxygen through the OxyMask or Venturi mask. Oxygen delivery was titrated to maintain SaO2 4% to 5% and 8% to 9% above baseline for two separate 30 min periods of stable breathing. Oxygen flow rate, partial pressure of inspired and expired oxygen (PO2) and carbon dioxide (PCO2), minute ventilation, heart rate, nasal and oral breathing, SaO2 and transcutaneous PCO2 were collected continuously. The study was repeated following alterations to the OxyMask design, which improved clearance of carbon dioxide. RESULTS: Thirteen patients, aged 28 to 79 years, were studied initially using the original OxyMask. Oxygen flow rate was lower, inspired PO2 was higher and expired PO2 was lower while using the OxyMask. Minute ventilation and inspired and expired PCO2 were significantly higher while using the OxyMask, whereas transcutaneous PCO2, heart rate and the ratio of nasal to oral breathing did not change significantly throughout the study. Following modification of the OxyMask, 13 additional patients, aged 18 to 79 years, were studied using the same protocol. The modified OxyMask provided a higher inspired PO2 at a lower flow rate, without evidence of carbon dioxide retention. CONCLUSIONS: Oxygen is delivered safely and more efficiently by the OxyMask than by the Venturi mask in stable oxygen-dependent patients. PMID:16896425

  1. Oxygen safety

    Science.gov (United States)

    ... sure you have working smoke detectors and a working fire extinguisher in your home. If you move around the house with your oxygen, you may need more than one fire extinguisher in different locations. Smoking can be very dangerous. No one should smoke ...

  2. On relation between the quark-gluon bag surface tension and the colour tube string tension

    International Nuclear Information System (INIS)

    Bugaev, K.A.; Zinovjev, G.M.

    2010-01-01

    We revisit the bag phenomenology of deconfining phase transition aiming to replenish it by introducing systematically the bag surface tension. Comparing the free energies of such bags and the strings confining the static quark-antiquark pair, we express the string tension in terms of the bag surface tension and the bulk pressure in order to estimate the bag characteristics using the lattice QCD (LQCD) data. Our analysis of the bag entropy density demonstrates that the surface tension coefficient is amazingly negative at the cross-over (continuous transition). The approach developed allows us to naturally account for an origin of a pronounced maximum (observed in the LQCD studies) in the behaviour of heavy quark-antiquark pair entropy. The vicinity of the (tri-)critical endpoint is also analyzed to clarify the meaning of vanishing surface tension coefficient.

  3. Transcutaneous Drainage of Gel-Like Substance after Application of Hydrogel Dural Sealant: Report of Two Cases.

    Science.gov (United States)

    Siman, Homayoun; Techy, Fernando

    2016-02-01

    Study Design Case report. Objective Incidental durotomy (IDT) is a common complication of spinal surgery. The use of collagen matrix graft along with hydrogel dural sealant is a common method of IDT repair. With this method, there have been several reported cases of detrimental dural sealant expansion in the literature. One case study reported an expansion rate greater than 300%; many report neurologic damage. This article reports the clinical course of two patients who developed postoperative transcutaneous drainage of a gel-like substance after the use of a dural sealant, which is a previously unreported complication. Methods The clinical course and treatment outcome of two patients is presented. Results Both patients experienced postoperative transcutaneous drainage of a gel-like substance at the surgical site. Case one began draining this substance on postoperative day 14. This patient required no further intervention, and the drainage ended after 3 mL of a gel-like substance was expressed from his incision while in the clinic. Case two began draining the gel on postoperative day 16. This patient underwent two washout procedures and resolution of the drainage. No infection was ever detected. Conclusions To our knowledge, our patients are the first reported cases of transcutaneous drainage of expanded dural sealant. It is important to take into consideration the unexpected expansion of a dural sealant when using it for the repair of IDT.

  4. The effects of transcutaneous low-level laser therapy on the skin healing process: an experimental model.

    Science.gov (United States)

    Ramos, Felipe Scholz; Maifrino, Laura Beatriz Mesiano; Alves, Sarah; da Costa Aguiar Alves, Beatriz; Perez, Matheus Moreira; Feder, David; Azzalis, Ligia Ajaime; Junqueira, Virginia Berlanga Campos; Fonseca, Fernando Luiz Affonso

    2018-01-06

    We aim to evaluate the action of transcutaneous laser in the initial wound healing process. The use of low-level laser therapy (LLLT) has proven to be effective on inflammatory modulation and wound healing. The trial was performed on five groups of rats, through a dorsal incision. All groups received treatment on auricular artery. Groups 1 and 3 were treated with transcutaneous LLLT over a period of 15 min. Groups 2 and 4 received one and two inactive laser applications (placebo), respectively. Group 5 was the control one. Blood samples were collected 2 h after the last application of LLLT so that cytokine levels could be measured by ELISA. Tissue fragments were harvested for morphometric, histomorphometric, and RT-qPCR analyses. The morphometric analysis revealed a greater decrease in the wounded area in G1 when compared with G2, whereas in G3, the improvement in the area was greater when compared with G4. Finally, the histomorphometric analysis showed that G1 was the group closer to G5 in terms of collagen fiber count. G2 and G4 had higher amounts of collagen fibers than G5 while G3 had a lower quantity. The use of the transcutaneous LLLT in the current study influenced the wound healing process.

  5. Optimal oxygen saturation in premature infants

    Directory of Open Access Journals (Sweden)

    Meayoung Chang

    2011-09-01

    Full Text Available There is a delicate balance between too little and too much supplemental oxygen exposure in premature infants. Since underuse and overuse of supplemental oxygen can harm premature infants, oxygen saturation levels must be monitored and kept at less than 95% to prevent reactive oxygen species-related diseases, such as retinopathy of prematurity and bronchopulmonary dysplasia. At the same time, desaturation below 80 to 85% must be avoided to prevent adverse consequences, such as cerebral palsy. It is still unclear what range of oxygen saturation is appropriate for premature infants; however, until the results of further studies are available, a reasonable target for pulse oxygen saturation (SpO2 is 90 to 93% with an intermittent review of the correlation between SpO2 and the partial pressure of arterial oxygen tension (PaO2. Because optimal oxygenation depends on individuals at the bedside making ongoing adjustments, each unit must define an optimal target range and set alarm limits according to their own equipment or conditions. All staff must be aware of these values and adjust the concentration of supplemental oxygen frequently.

  6. Oxygen therapy - infants

    Science.gov (United States)

    ... breathe increased amounts of oxygen to get normal levels of oxygen in their blood. Oxygen therapy provides babies with the extra oxygen. Information Oxygen is a gas that the cells in your body need to work properly. The ...

  7. Fatigue in tension perpendicular to the grain

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben

    1999-01-01

    Traditinally fatigue resistance is quantified as number of cycles to failure at a given stress level. A previous study by the authors showed that fatigue in compression parallel to the grain is governed partly by duration of load and partly by an effect of loading, i.e. a combination of a creep...... mechanism and a mechanism connected to damage introduce in the loading sequences. The purpose of the present study is to disentangle the effect of duration of load from the effect of load oscillation in fatigue in tension perpendicular to the grain. Fatigue experiments are made on small specimens...... and on dowel type joints with slotted in steel plates. In series of ten, the small specimens are taken to fatigue failure in uniform tension at square wave shaped load cycles at 0.01 Hz and 0.1 Hz. In order to test the predictive validity of the result from the small tension specimens, fatigue experiments...

  8. Fatigue In Tension Perpendicular to the Grain

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Uhre; Hoffmeyer, Preben

    2004-01-01

    Traditionally fatigue resistance is quantified as number of cycles to failure at a given stress level. A previous study by the authors showed that fatigue in compression parallel to the grain is governed partly by duration of load and partly by an effect of loading, i.e. a combination of a creep...... mechanism and a mechanism connected to damage introduced in the loading sequences. The purpose of the present study is to disentangle the effect of duration of load from the effect of load oscillation in fatigue in tension perpendicular to the grain. Fatigue experiments are made on small specimens...... and on dowel type joints with slotted in steel plates. In series of ten, the small specimens are taken to fatigue failure in uniform tension at square wave shaped load cycles at 0.01 Hz and 0.1 Hz. In arder to test the predictive validity of the result from the small tension specimens, fatigue experiments...

  9. Tensions between Teams and Their Leaders

    Directory of Open Access Journals (Sweden)

    J. David Johnson

    2016-10-01

    Full Text Available The intersection of teamwork and leadership results in tensions, dilemmas, and paradoxes for both individuals and for institutions such as simultaneously empowering individuals at the same time it frustrates them when our naive, cultural understanding of leadership centralizes power and values leaders who can impose their will and vision on others. Perhaps the fundamental paradox of teamwork and leadership is that the more leadership is focused on an individual the less likely a team’s potential will be realized. Six specific domains where tensions arise are: at team boundaries; culture; who is in charge, rationality/cognition; diversity; and collaborations. Three approaches - clarifying different levels of analysis, temporal factors, and overarching concepts - to resolving tensions are discussed. New conceptions of leadership and the importance of the larger cultural frame within which they are embedded are needed for the management of technology and innovation.

  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. Surface tension of normal and heavy water

    International Nuclear Information System (INIS)

    Straub, J.; Rosner, N.; Grigull, V.

    1980-01-01

    A Skeleton Table and simple interpolation equation for the surface tension of light water was developed by the Working Group III of the International Association for the Properties of Steam and is recommended as an International Standard. The Skeleton Table is based on all known measurements of the surface tension and individual data were weighted corresponding to the accuracy of the measurements. The form of the interpolation equation is based on a physical concept. It represents an extension of van der Waals-equation, where the exponent conforms to the 'Scaling Laws'. In addition for application purposes simple relations for the Laplace-coefficient and for the density difference between the liquid and gaseous phases of light water are given. The same form of interpolation equation for the surface tension can be used for heavy water, for which the coefficients are given. However, this equation is based only on a single set of data. (orig.) [de

  12. Tension Stiffened and Tendon Actuated Manipulator

    Science.gov (United States)

    Doggett, William R. (Inventor); Dorsey, John T. (Inventor); Ganoe, George G. (Inventor); King, Bruce D. (Inventor); Jones, Thomas C. (Inventor); Mercer, Charles D. (Inventor); Corbin, Cole K. (Inventor)

    2015-01-01

    A tension stiffened and tendon actuated manipulator is provided performing robotic-like movements when acquiring a payload. The manipulator design can be adapted for use in-space, lunar or other planetary installations as it is readily configurable for acquiring and precisely manipulating a payload in both a zero-g environment and in an environment with a gravity field. The manipulator includes a plurality of link arms, a hinge connecting adjacent link arms together to allow the adjacent link arms to rotate relative to each other and a cable actuation and tensioning system provided between adjacent link arms. The cable actuation and tensioning system includes a spreader arm and a plurality of driven and non-driven elements attached to the link arms and the spreader arm. At least one cable is routed around the driven and non-driven elements for actuating the hinge.

  13. Radiosensitivity of Hela cells in various O2 concentrations and consideration of oxygen effect in radiotherapy

    International Nuclear Information System (INIS)

    Kuroda, Yoshikazu; Nyunoya, Koichiro

    1979-01-01

    The aim of this paper is the study of the radiosensitivity of HeLa cells in vitro in various oxygen concentrations and the consideration of the utilization of oxygen effect in radiation therapy, based on the data of HeLa cells and tumor oxygen tension. Survival curves of HeLa cells are found to be exponential as a function of radiation dose and the radiosensitivity is dependent on oxygen tension of culture medium. Relative radiosensitivity decreases remarkably at low level of oxygen, especially under 9 mmHg pO 2 . The utilization of oxygen effect in radiation may be useful in hyperbaric oxygen inhalation and not useful under local tissue hypoxia induced by tourniquet application. Reoxygenation occurs with shrinkage of tumor after irradiation and this phenomenon will diminish the value of hyperbaric oxygen in radiation therapy. (author)

  14. Oxygen dynamics around buried lesser sandeels Ammodytes tobianus (Linnaeus 1785): mode of ventilation and oxygen requirements

    DEFF Research Database (Denmark)

    Behrens, Jane W; Stahl, Henrik J; Steffensen, John F

    2007-01-01

    The oxygen environment around buried sandeels (Ammodytes tobianus) was monitored by planar optodes. The oxygen penetration depth at the sediment interface was only a few mm. Thus fish, typically buried at 1-4 cm depth, were generally in anoxic sediment. However, they induced an advective transport...... down along the body, referred to as ;plume ventilation'. Yet, within approximately 30 min the oxic plume was replenished by oxygen-depleted water from the gills. The potential for cutaneous respiration by the buried fish was thus of no quantitative importance. Calculations derived by three independent...... methods (each with N=3) revealed that the oxygen uptake of sandeel buried for 6-7 h was 40-50% of previous estimates on resting respirometry of non-buried fish, indicating lower O(2) requirements during burial on a diurnal timescale. Buried fish exposed to decreasing oxygen tensions gradually approached...

  15. Accuracy of Transcutaneous CO2 Values Compared With Arterial and Capillary Blood Gases.

    Science.gov (United States)

    Lambert, Laura L; Baldwin, Melissa B; Gonzalez, Cruz Velasco; Lowe, Gary R; Willis, J Randy

    2018-05-08

    Transcutaneous monitors are utilized to monitor a patient's respiratory status. Some patients have similar values when comparing transcutaneous carbon dioxide ( P tcCO 2 ) values with blood gas analysis, whereas others show extreme variability. A retrospective review of data was performed to determine how accurately P tcCO 2 correlated with CO 2 values obtained by arterial blood gas (ABG) or capillary blood gas. To determine whether P tcCO 2 values correlated with ABG or capillary blood gas values, subjects' records were retrospectively reviewed. Data collected included the P tcCO 2 value at the time of blood gas procurement and the ABG or capillary blood gas P CO 2 value. Agreement of pairs of methods (ABG vs P tcCO 2 and capillary blood gas vs P tcCO 2 ) was assessed with the Bland-Altman approach with limits of agreement estimated with a mixed model to account for serial measurements per subject. A total of 912 pairs of ABG/ P tcCO 2 values on 54 subjects and 307 pairs of capillary blood gas/ P tcCO 2 values on 34 subjects were analyzed. The P CO 2 range for ABG was 24-106 mm Hg, and P tcCO 2 values were 27-133 mm Hg. The P CO 2 range for capillary blood gas was 29-108 mm Hg, and P tcCO 2 values were 30-103 mm Hg. For ABG/ P tcCO 2 comparisons, the Pearson correlation coefficient was 0.82, 95% CI was 0.80-0.84, and P was <.001. For capillary blood gas/ P tcCO 2 comparisons, the Pearson correlation coefficient was 0.77, 95% CI was 0.72-0.81, and P was <.001. For ABG/ P tcCO 2 , the estimated difference ± SD was -6.79 t± 7.62 mm Hg, and limits of agreement were -22.03 to 8.45. For capillary blood gas/ P tcCO 2 , the estimated difference ± SD was -1.61 ± 7.64 mm Hg, and limits of agreement were -16.88 to 13.66. The repeatability coefficient was about 30 mm Hg. Based on these data, capillary blood gas comparisons showed less variation and a slightly lower correlation with P tcCO 2 than did ABG comparisons. After accounting for serial measurements per patient

  16. Transcutaneous immunization with a novel imiquimod nanoemulsion induces superior T cell responses and virus protection.

    Science.gov (United States)

    Lopez, Pamela Aranda; Denny, Mark; Hartmann, Ann-Kathrin; Alflen, Astrid; Probst, Hans Christian; von Stebut, Esther; Tenzer, Stefan; Schild, Hansjörg; Stassen, Michael; Langguth, Peter; Radsak, Markus P

    2017-09-01

    Transcutaneous immunization (TCI) is a novel vaccination strategy utilizing the skin associated lymphatic tissue to induce immune responses. TCI using a cytotoxic T lymphocyte (CTL) epitope and the Toll-like receptor 7 (TLR7) agonist imiquimod mounts strong CTL responses by activation and maturation of skin-derived dendritic cells (DCs) and their migration to lymph nodes. However, TCI based on the commercial formulation Aldara only induces transient CTL responses that needs further improvement for the induction of durable therapeutic immune responses. Therefore we aimed to develop a novel imiquimod solid nanoemulsion (IMI-Sol) for TCI with superior vaccination properties suited to induce high quality T cell responses for enhanced protection against infections. TCI was performed by applying a MHC class I or II restricted epitope along with IMI-Sol or Aldara (each containing 5% Imiquimod) on the shaved dorsum of C57BL/6, IL-1R, Myd88, Tlr7 or Ccr7 deficient mice. T cell responses as well as DC migration upon TCI were subsequently analyzed by flow cytometry. To determine in vivo efficacy of TCI induced immune responses, CTL responses and frequency of peptide specific T cells were evaluated on day 8 or 35 post vaccination and protection in a lymphocytic choriomeningitis virus (LCMV) infection model was assessed. TCI with the imiquimod formulation IMI-Sol displayed equal skin penetration of imiquimod compared to Aldara, but elicited superior CD8 + as well as CD4 + T cell responses. The induction of T-cell responses induced by IMI-Sol TCI was dependent on the TLR7/MyD88 pathway and independent of IL-1R. IMI-Sol TCI activated skin-derived DCs in skin-draining lymph nodes more efficiently compared to Aldara leading to enhanced protection in a LCMV infection model. Our data demonstrate that IMI-Sol TCI can overcome current limitations of previous imiquimod based TCI approaches opening new perspectives for transcutaneous vaccination strategies and allowing the use of this

  17. Effects of transcutaneous electrical stimulation of lower limb muscles on experimental fatty liver.

    Science.gov (United States)

    El-Kafoury, Bataa M; Seif, Ansam A; El-Aziz Abd El-Hady, Enas A; El-Sebaiee, Ahmed E

    2016-03-01

    Although the beneficial effects of exercise on fatty liver have been described, a previous study conducted at our department showed that transcutaneous electrical muscle stimulation (TEMS) of lower abdominal muscles aggravated fatty liver. The present study aims to evaluate the ability of TEMS of the lower limb muscles to improve fatty liver infiltration. Thirty male Wistar rats were randomly allocated into three groups: control; fructose-fed (F), fed fructose-enriched diet for 6weeks; and fructose-fed with transcutaneous electrical muscle stimulation (F+TEMS), fed fructose-enriched diet for 6weeks and lower limb muscles subjected to TEMS during the last 3weeks of feeding, five sessions/week. Body weight, length, body mass index (BMI), and abdominal and lower limb circumferences were all recorded. Fasting blood glucose, serum insulin, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total protein, serum albumin, high density lipoprotein cholesterol (HDL-C), triglyceride (TG), and total cholesterol (TC) levels were measured. LDL cholesterol (LDL-C) and the atherogenic index (AI) were calculated. Absolute and relative hepatic weights as well as histological examination of the liver were assessed. Final body weight, abdominal and lower limb circumferences, absolute liver weight, homoeostasis model assessment (HOMA) score, and TG, LDL-C, AI, serum ALT, and AST levels were all significantly reduced in the (F+TEMS) group compared to the (F) group. There was a significant increase in GPx and HDL-C levels, HDL/LDL ratio, and total protein and serum albumin content in (F+TEMS) rats compared to (F) rats. Histologically, hepatic tissue from (F+TEMS) rats had minimal steatotic changes that were restricted to zone 1 and less marked inflammatory cell infiltration compared to (F) rats. TEMS was able to reverse steatosis, hyperglycaemia, insulin resistance, dyslipidaemia, and fatty liver caused by fructose feeding. The study confirmed that the variation in

  18. Focal adhesions, stress fibers and mechanical tension

    Energy Technology Data Exchange (ETDEWEB)

    Burridge, Keith, E-mail: Keith_Burridge@med.unc.edu [Department of Cell Biology and Physiology, and Lineberger Comprehensive Cancer Center, 12-016 Lineberger, CB#7295, University of North Carolina, Chapel Hill, NC (United States); Guilluy, Christophe, E-mail: christophe.guilluy@univ-nantes.fr [Inserm UMR-S1087, CNRS UMR-C6291, L' institut du Thorax, and Université de Nantes, Nantes (France)

    2016-04-10

    Stress fibers and focal adhesions are complex protein arrays that produce, transmit and sense mechanical tension. Evidence accumulated over many years led to the conclusion that mechanical tension generated within stress fibers contributes to the assembly of both stress fibers themselves and their associated focal adhesions. However, several lines of evidence have recently been presented against this model. Here we discuss the evidence for and against the role of mechanical tension in driving the assembly of these structures. We also consider how their assembly is influenced by the rigidity of the substratum to which cells are adhering. Finally, we discuss the recently identified connections between stress fibers and the nucleus, and the roles that these may play, both in cell migration and regulating nuclear function. - Highlights: • The different types of stress fiber and focal adhesion are described. • We discuss the controversy about tension and assembly of these structures. • We describe the different models used to investigate assembly of these structures. • The influence of substratum rigidity is discussed. • Stress fiber connections to the nucleus are reviewed.

  19. Inclusion and Participation: Working with the Tensions

    Directory of Open Access Journals (Sweden)

    Gideon Calder

    2011-12-01

    Full Text Available Democracy is crucially about inclusion: a theory of democracy must account for who is to be included in the democratic process, how, and on what terms. Inclusion, if conceived democratically, is fraught with tensions. This article identifies three such tensions, arising respectively in: (i the inauguration of the democratic public; (ii enabling equal participation; and (iii the relationship between instrumental and non-instrumental accounts of democracy’s value. In each case, I argue, rather than seeking somehow to dissolve or avoid such tensions, theories of democracy should allow us to live with their implications reflexively: to work with them. Such tensions are counter-democratic to the extent that they derail what Nancy Fraser calls “participatory parity,” under which citizens count as “full partners in social interaction.” But the extent to which they do this is not itself dependent on points of paradox in the very idea of inclusion. Such parity relies on complex factors, social and economic, which democratic institutions and procedures will not by themselves address. To achieve full democratic inclusion we must already have addressed such factors; no account of democracy itself, however finely-tuned, will do this.

  20. Tension and relaxation in the individual.

    Science.gov (United States)

    Newbury, C R

    1979-06-01

    Increasing materialism in society is resulting in more wide spread nervous tension in all age groups. While some degree of nervous tension is necessary in everyday living, its adverse effects require that we must learn to bring it under control. Total tension is shown to have two components: a controllable element arising from factors in the environment and the inbuilt uncontrollable residue which is basic in the individual temperament. The effects of excessive or uncontrolled stress can be classified as 1) emotional reactions such as neurotic behaviour (anxiety hypochondria, hysteria, phobia, depression obsessions and compulsions) or psychotic behaviour and 2) psychosomatic reactions (nervous asthma, headache, insomnia, heart attack). Nervous energy can be wastefully expended by such factors as loss of temper, wrong attitudes to work, job frustration and marital strains. Relaxation is the only positive way to control undesirable nervous tension and its techniques require to be learned. A number of techniques (progressive relaxation, differential relaxation, hypnosis, the use of biofeedback, Yoga and Transcendental Meditation) are described and their application to dental practice is discussed.

  1. WORRY, ANXIETY AND TENSION — IMPORTANCE ...

    African Journals Online (AJOL)

    Enrique

    cognitive. Tension: Increased and unpleasant motor and psychological activity or a state of mental or ... MRC Research Unit on Anxiety and Stress. Disorders ... and brain imaging. Worry ... serve an adaptive function to the daily challenges of our environment. ... connection to physical symptoms ... Experience-conditioning.

  2. Surface Tension Measurements with a Smartphone

    Science.gov (United States)

    Goy, Nicolas-Alexandre; Denis, Zakari; Lavaud, Maxime; Grolleau, Adrian; Dufour, Nicolas; Deblais, Antoine; Delabre, Ulysse

    2017-01-01

    Smartphones are increasingly used in higher education and at university in mechanics, acoustics, and even thermodynamics as they offer a unique way to do simple science experiments. In this article, we show how smartphones can be used in fluid mechanics to measure surface tension of various liquids, which could help students understand the concept…

  3. Rebellion and Agrarian Tensions in Sierra Leone

    NARCIS (Netherlands)

    Peters, K.; Richards, P.

    2011-01-01

    This paper assesses the extent to which customary governance in Sierra Leone can be held responsible for an increasingly unstable two-class agrarian society. A case is made for regarding the civil war (1991–2002) as being an eruption of long-term, entrenched agrarian tensions exacerbated by chiefly

  4. Normal tension glaucoma and Alzheimer disease

    DEFF Research Database (Denmark)

    Bach-Holm, Daniella; Kessing, Svend Vedel; Mogensen, Ulla Brasch

    2012-01-01

    Purpose: To investigate whether normal tension glaucoma (NTG) is associated with increased risk of developing dementia/Alzheimer disease (AD). Methods: A total of 69 patients with NTG were identified in the case note files in the Glaucoma Clinic, University Hospital of Copenhagen (Rigshospitalet...

  5. Coexisting tensions between the 'traditionmodernity' and the ...

    African Journals Online (AJOL)

    Coexisting tensions between the 'traditionmodernity' and the 'sustainability- integration' approaches to urban development policy and planning practices in Botswana. ... exists at several levels and manifest in urban planning's preoccupation with the physicality of spatial forms, often justified in the embracing of globalization.

  6. Tension and Approximation in Poetic Translation

    Science.gov (United States)

    Al-Shabab, Omar A. S.; Baka, Farida H.

    2015-01-01

    Simple observation reveals that each language and each culture enjoys specific linguistic features and rhetorical traditions. In poetry translation difference and the resultant linguistic tension create a gap between Source Language and Target language, a gap that needs to be bridged by creating an approximation processed through the translator's…

  7. Internationalization and Global Tension: Lessons From History

    Science.gov (United States)

    Altbach, Philip G.; de Wit, Hans

    2015-01-01

    Increasing political and military tension in several parts of the world will inevitably affect international higher education. Nationalist, religious, and ideological conflicts challenge the original ideas of international cooperation and exchange in higher education as promoters of peace and mutual understanding and of global engagement. Since…

  8. Educational Leadership: Key Challenges and Ethical Tensions

    Science.gov (United States)

    Duignan, Patrick

    2007-01-01

    "Educational Leadership" is a major research book on contemporary leadership challenges for educational leaders. In this groundbreaking new work, educational leaders in schools, including teachers, are provided with ways of analysing and resolving common but complex leadership challenges. Ethical tensions inherent in these challenges are…

  9. Tension Builds over AFT Reform Agenda

    Science.gov (United States)

    Sawchuk, Stephen

    2012-01-01

    Can a teachers' union successfully be both a hardball-playing defender of its rights and a collaborative force for the common good? It is both a question of philosophy and, increasingly, one of policy direction for the American Federation of Teachers (AFT), whose biennial convention in Detroit showed delegates grappling with the tension between…

  10. Exact analytical density profiles and surface tension

    Indian Academy of Sciences (India)

    journal of. May 2005 physics pp. 785–801. Classical charged fluids at equilibrium near ... is provided by the excess surface tension for an air–water interface, which is determined ... the potential drop created by the electric layer which appears as soon as the fluid has ...... radii, by symmetry, the charge density profile is flat,.

  11. Transitions of tethered chain molecules under tension.

    Science.gov (United States)

    Luettmer-Strathmann, Jutta; Binder, Kurt

    2014-09-21

    An applied tension force changes the equilibrium conformations of a polymer chain tethered to a planar substrate and thus affects the adsorption transition as well as the coil-globule and crystallization transitions. Conversely, solvent quality and surface attraction are reflected in equilibrium force-extension curves that can be measured in experiments. To investigate these effects theoretically, we study tethered chains under tension with Wang-Landau simulations of a bond-fluctuation lattice model. Applying our model to pulling experiments on biological molecules we obtain a good description of experimental data in the intermediate force range, where universal features dominate and finite size effects are small. For tethered chains in poor solvent, we observe the predicted two-phase coexistence at transitions from the globule to stretched conformations and also discover direct transitions from crystalline to stretched conformations. A phase portrait for finite chains constructed by evaluating the density of states for a broad range of solvent conditions and tensions shows how increasing tension leads to a disappearance of the globular phase. For chains in good solvents tethered to hard and attractive surfaces we find the predicted scaling with the chain length in the low-force regime and show that our results are well described by an analytical, independent-bond approximation for the bond-fluctuation model for the highest tensions. Finally, for a hard or slightly attractive surface the stretching of a tethered chain is a conformational change that does not correspond to a phase transition. However, when the surface attraction is sufficient to adsorb a chain it will undergo a desorption transition at a critical value of the applied force. Our results for force-induced desorption show the transition to be discontinuous with partially desorbed conformations in the coexistence region.

  12. Multispectral imaging of acute wound tissue oxygenation

    Directory of Open Access Journals (Sweden)

    Audrey Huong

    2017-05-01

    Full Text Available This paper investigates the appropriate range of values for the transcutaneous blood oxygen saturation (StO2 of granulating tissues and the surrounding tissue that can ensure timely wound recovery. This work has used a multispectral imaging system to collect wound images at wavelengths ranging between 520nm and 600nm with a resolution of 10nm. As part of this research, a pilot study was conducted on three injured individuals with superficial wounds of different wound ages at different skin locations. The StO2 value predicted for the examined wounds using the Extended Modified Lambert–Beer model revealed a mean StO2 of 61±10.3% compared to 41.6±6.2% at the surrounding tissues, and 50.1±1.53% for control sites. These preliminary results contribute to the existing knowledge on the possible range and variation of wound bed StO2 that are to be used as indicators of the functioning of the vasomotion system and wound health. This study has concluded that a high StO2 of approximately 60% and a large fluctuation in this value should precede a good progression in wound healing.

  13. Transcutaneous Intraluminal Impedance Measurement for Minimally Invasive Monitoring of Gastric Motility: Validation in Acute Canine Models

    Directory of Open Access Journals (Sweden)

    Michael D. Poscente

    2014-01-01

    Full Text Available Transcutaneous intraluminal impedance measurement (TIIM is a new method to cutaneously measure gastric contractions by assessing the attenuation dynamics of a small oscillating voltage emitted by a battery-powered ingestible capsule retained in the stomach. In the present study, we investigated whether TIIM can reliably assess gastric motility in acute canine models. Methods. Eight mongrel dogs were randomly divided into 2 groups: half received an active TIIM pill and half received an identically sized sham capsule. After 24-hour fasting and transoral administration of the pill (active or sham, two force transducers (FT were sutured onto the antral serosa at laparotomy. After closure, three standard cutaneous electrodes were placed on the abdomen, registering the transluminally emitted voltage. Thirty-minute baseline recordings were followed by pharmacological induction of gastric contractions using neostigmine IV and another 30-minute recording. Normalized one-minute baseline and post-neostigmine gastric motility indices (GMIs were calculated and Pearson correlation coefficients (PCCs between cutaneous and FT GMIs were obtained. Statistically significant GMI PCCs were seen in both baseline and post-neostigmine states. There were no significant GMI PCCs in the sham capsule test. Further chronic animal studies of this novel long-term gastric motility measurement technique are needed before testing it on humans.

  14. Transcutaneous vagus nerve stimulation (tVNS) enhances recognition of emotions in faces but not bodies.

    Science.gov (United States)

    Sellaro, Roberta; de Gelder, Beatrice; Finisguerra, Alessandra; Colzato, Lorenza S

    2018-02-01

    The polyvagal theory suggests that the vagus nerve is the key phylogenetic substrate enabling optimal social interactions, a crucial aspect of which is emotion recognition. A previous study showed that the vagus nerve plays a causal role in mediating people's ability to recognize emotions based on images of the eye region. The aim of this study is to verify whether the previously reported causal link between vagal activity and emotion recognition can be generalized to situations in which emotions must be inferred from images of whole faces and bodies. To this end, we employed transcutaneous vagus nerve stimulation (tVNS), a novel non-invasive brain stimulation technique that causes the vagus nerve to fire by the application of a mild electrical stimulation to the auricular branch of the vagus nerve, located in the anterior protuberance of the outer ear. In two separate sessions, participants received active or sham tVNS before and while performing two emotion recognition tasks, aimed at indexing their ability to recognize emotions from facial and bodily expressions. Active tVNS, compared to sham stimulation, enhanced emotion recognition for whole faces but not for bodies. Our results confirm and further extend recent observations supporting a causal relationship between vagus nerve activity and the ability to infer others' emotional state, but restrict this association to situations in which the emotional state is conveyed by the whole face and/or by salient facial cues, such as eyes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. US-guided transcutaneous tru-cut biopsy of laryngo-hypopharyngeal lesions

    Energy Technology Data Exchange (ETDEWEB)

    Preda, Lorenzo; De Fiori, Elvio; Rampinelli, Cristiano; Petralia, Giuseppe; Bonello, Luke [European Institute of Oncology, Department of Radiology, Milan (Italy); Ansarin, Mohssen; Chiesa, Fausto [European Institute of Oncology, Department of Head and Neck Surgery, Milan (Italy); Maffini, Fausto [European Institute of Oncology, Patology Division, Laboratory of Anatomy, Milan (Italy); Alterio, Daniela [European Institute of Oncology, Radiotherapy Division, Milan (Italy); Bellomi, Massimo [European Institute of Oncology, Department of Radiology, Milan (Italy); University of Milan, School of Medicine, Milan (Italy)

    2010-06-15

    To evaluate the feasibility and performance of ultrasound-guided transcutaneous tru-cut biopsy (USGTCB) in selected patients (with stenosis of airways or difficult intubation or contraindication to general anaesthesia) with untreated or previously treated suspicious laryngo-hypopharyngeal masses. Biopsies were performed with a free-hand technique by a single radiologist. Thirty-six USGTCBs were scheduled in 34 patients (24 males, 10 females; age range 47-95 years). Two USGTCBs were not performed, as lesions were not detectable: therefore, 16 USGTCBs were performed for an untreated mass suspicious for malignancy and 18 were performed for a mass suspicious for recurrence after radiotherapy alone, or associated with endoscopic laser surgery or chemotherapy. USGTCB diagnosed 25 squamous cell carcinomas (73.5%) and nine benign lesions (26.5%); no false positives and two false negatives were reported, both in patients previously treated with radiotherapy. The sensitivity, specificity, positive and negative predictive value of the technique was 92.5%, 100%, 100% and 77.7% respectively, with no major complications. Although biopsy under microlaryngoscopy remains the ''gold-standard'' technique, USGTCB is feasible, carries the advantages of avoiding general anaesthesia, is suitable for outpatients and is cost-effective. If applied to selected patients, it could be considered for the histological diagnosis of both primary and recurrent laryngo-hypopharyngeal masses. (orig.)

  16. Effect of transcutaneous electrical nerve stimulation induced parotid stimulation on salivary flow

    Directory of Open Access Journals (Sweden)

    Sreenivasulu Pattipati

    2013-01-01

    Full Text Available Aims and Objectives: The main objective of this study was to evaluate the duration of stimulation over the parotid salivary flow following the use of transcutaneous electric nerve stimulation (TENS in different age groups. Materials and Methods: The study was carried out in three different age groups. Under group A individuals from 21 to 35 years of age, group B 36-50 years and group C above 51 years were considered. In each group 30 subjects were taken of whom 15 were males and 15 were females. The placement of pads was approximated bilaterally over the parotid glands. The working parameters of TENS unit were fixed at 50 Hz and the unit was in normal mode. Results: Subjects belonging to group B were showing statistically significant increases in the duration of stimulated parotid salivary flow following the use of TENS. Conclusion: TENS can be considered as a non-pharmacological alternative to improve salivation for longer period in xerostomia patients.

  17. Transcutaneous measurement of glomerular filtration rate in small rodents: through the skin for the win?

    Science.gov (United States)

    Ellery, Stacey J; Cai, Xiaochu; Walker, David D; Dickinson, Hayley; Kett, Michelle M

    2015-03-01

    Rodent models of renal physiology and pathology are crucial to our understanding of the molecular, histological and functional sequelae that contribute to kidney diseases. One of the most important measures of renal function is glomerular filtration rate (GFR). While the accurate determination of GFR is pivotal to understanding the progression of disease and/or the benefits of treatment strategies, in rodents the conventional methods for assessment of GFR are inconvenient and cumbersome, not the least because they involve stress and often anaesthesia. The legitimacy of assay-based assessment of plasma and urine markers of GFR in mice has also been heavily scrutinized for their insensitivity to minor declines in GFR and inaccurate detection of renal biomarkers. While infusion-based clearance methods of GFR assessment are thus the gold standard in terms of accuracy, they are limited by the fact that they are primarily non-recovery procedures. This presents a dilemma when trying to document the progression of renal disease, as these measures cannot be taken in the same experimental subject. Here we review a technique of transcutaneous measurement of fluorescein isothiocyanate-labelled sinistrin to calculate GFR in small rodents, using a non-invasive clearance device (NIC-Kidney Device). This is a recently validated non-invasive technique for measuring GFR in small rodents that allows for the real-time measurement of GFR in conscious animals, without the need for plasma and urine assays. © 2014 Asian Pacific Society of Nephrology.

  18. Dynamic impedance model of the skin-electrode interface for transcutaneous electrical stimulation.

    Directory of Open Access Journals (Sweden)

    José Luis Vargas Luna

    Full Text Available Transcutaneous electrical stimulation can depolarize nerve or muscle cells applying impulses through electrodes attached on the skin. For these applications, the electrode-skin impedance is an important factor which influences effectiveness. Various models describe the interface using constant or current-depending resistive-capacitive equivalent circuit. Here, we develop a dynamic impedance model valid for a wide range stimulation intensities. The model considers electroporation and charge-dependent effects to describe the impedance variation, which allows to describe high-charge pulses. The parameters were adjusted based on rectangular, biphasic stimulation pulses generated by a stimulator, providing optionally current or voltage-controlled impulses, and applied through electrodes of different sizes. Both control methods deliver a different electrical field to the tissue, which is constant throughout the impulse duration for current-controlled mode or have a very current peak for voltage-controlled. The results show a predominant dependence in the current intensity in the case of both stimulation techniques that allows to keep a simple model. A verification simulation using the proposed dynamic model shows coefficient of determination of around 0.99 in both stimulation types. The presented method for fitting electrode-skin impedance can be simple extended to other stimulation waveforms and electrode configuration. Therefore, it can be embedded in optimization algorithms for designing electrical stimulation applications even for pulses with high charges and high current spikes.

  19. Comparison of Transcutaneous Electrical Nerve Stimulation and Parasternal Block for Postoperative Pain Management after Cardiac Surgery

    Directory of Open Access Journals (Sweden)

    Nilgun Kavrut Ozturk

    2016-01-01

    Full Text Available Background. Parasternal block and transcutaneous electrical nerve stimulation (TENS have been demonstrated to produce effective analgesia and reduce postoperative opioid requirements in patients undergoing cardiac surgery. Objectives. To compare the effectiveness of TENS and parasternal block on early postoperative pain after cardiac surgery. Methods. One hundred twenty patients undergoing cardiac surgery were enrolled in the present randomized, controlled prospective study. Patients were assigned to three treatment groups: parasternal block, intermittent TENS application, or a control group. Results. Pain scores recorded 4 h, 5 h, 6 h, 7 h, and 8 h postoperatively were lower in the parasternal block group than in the TENS and control groups. Total morphine consumption was also lower in the parasternal block group than in the TENS and control groups. It was also significantly lower in the TENS group than in the control group. There were no statistical differences among the groups regarding the extubation time, rescue analgesic medication, length of intensive care unit stay, or length of hospital stay. Conclusions. Parasternal block was more effective than TENS in the management of early postoperative pain and the reduction of opioid requirements in patients who underwent cardiac surgery through median sternotomy. This trial is registered with Clinicaltrials.gov number NCT02725229.

  20. Effectiveness of transcutaneous electrical nerve stimulation on saliva production in post-radiated oral cancer patients

    Directory of Open Access Journals (Sweden)

    Sakshi Ojha

    2016-01-01

    Full Text Available Aims and Objectives: To determine the effectiveness of transcutaneous electrical nerve stimulation (TENS in stimulating salivary flow in post-radiated oral cancer patients, and to compare the salivary flow rate between unstimulated saliva and saliva stimulated with TENS in post-radiated oral cancer patients. Materials and Methods: In 30 patients who underwent radiotherapy for oral cancer, unstimulated saliva was collected every minute for 5 min in a graduated test tube. The TENS unit was activated and stimulated saliva was collected for 5 min in a separate graduated test tube, and the flow rate was compared with the unstimulated salivary flow rate. Results: A statistically significant improvement was seen in saliva production during stimulation (P < 0.001. In addition, statistically significant increase in TENS stimulated saliva was observed in patients aged ≥50 years compared to that in patients aged <50 years (P < 0.05. There was no significant difference in salivary flow rate between the two genders in both stimulated and unstimulated conditions, however, statistically significant increase in salivary flow rate was observed in males under stimulated condition (P < 0.01. Conclusion: TENS was highly effective in stimulating the whole salivary flow rate in post-radiated oral cancer patients. It is an effective supportive treatment modality in xerostomia patients caused by radiotherapy in oral cancer patients.

  1. [Chronic fatigue syndrome treated with transcutaneous electrical acupoint stimulation: a randomized controlled trial].

    Science.gov (United States)

    Li, Jinxia; Xie, Jingjun; Pan, Zhongqiang; Guo, Xiaoqing; Li, Ye; Fu, Ruiyang

    2017-12-12

    To evaluate the clinical therapeutic effects and safety of chronic fatigue syndrome treated with transcutaneous electrical acupoint stimulation (TEAS) on the conception vessel and the governor vessel. Eighty-nine patients of chronic fatigue syndrome were randomized into an observation group (46 cases) and a control group (43 cases). In the observation group, TEAS was applied at Dazhui (GV 14) and Mingmen (GV 4), Shenque (CV 8) and Guanyuan (CV 4) [the current intensity: (14±2) mA]. In the control group, the simulated TEAS was applied at the same acupoints as the observation group (the current intensity: 1 mA). The treatment was given for 30 min, once a day, 5 times a week and the treatment of 4 weeks was as 1 session in the two groups. One session of treatment was required. Before treatment and at the end of 1 session of treatment, the fatigue severity scale (FSS) was adopted to evaluate the fatigue symptoms and the somatic and psychological health report (SPHERE) was adopted to evaluate the potential symptoms and observe the safety of TEAS therapy. At the end of treatment, FSS score and SPHERE score in the control group were not different significantly as compared with those before treatment (both P >0.05). FSS score and SPHERE score in the observation group were reduced significantly as compared with those before treatment (both P fatigue symptoms and the potential symptoms in the patients of chronic fatigue syndrome. It is a safe therapy.

  2. Electromagnetic Compatibility of Transcutaneous Energy Transmission Systemfor Totally Implantable Artificial Heart

    Science.gov (United States)

    Shiba, Kenji; Koshiji, Kohji

    Transcutaneous Energy Transmission (TET) is one way of providing the energy needed to power a totally implantable artificial heart (TIAH). In the present study, an externally coupled TET system was implanted in a prototype human phantom to evaluate emission and immunity. In the emission evaluation, measurements were conducted based on CISPR Pub.11 and VDE 0871 standards, while immunity tests were based on the standards of the IEC 61000-4 series. The magnetic field of the radiated emission was measured using a loop antenna. At 0.1[MHz], we found the greatest magnetic field of 47.8 [dBμA/m], somewhat less than CISPR’s upper limit of 54 [dBμA/m]. For the conducted emission, by installing a noise filter and ferrite beads in the input section of the DC-power supply, conducted emission could be kept within the allowable limits of CISPR Pub.11 and VDE 0871. Finally, the immunity tests against radiated and conducted emission, electrostatic discharge and voltage fluctuation proved that the prototype could withstand the maximum level of disturbance. These results confirmed that the TET system implanted in a human phantom could, through modification, meet the emission and immunity standards.

  3. Modifications of baropodograms after transcutaneous electric stimulation of the abductor hallucis muscle in humans standing erect.

    Science.gov (United States)

    Gaillet, Jean-Claude; Biraud, Jean-Claude; Bessou, Monique; Bessou, Paul

    2004-12-01

    Objective data on abductor hallucis muscle biomechanical function in the loaded foot (subject standing erect on both legs) are unavailable. To evaluate the effects of electrical stimulation of the abductor hallucis muscle in the loaded foot on the change of plantar pressures, as measured by digital baropodograms. Six indices were defined to compare baropodograms. The abductor hallucis muscle in 1 foot was subjected to transcutaneous electrical stimulation (20 min) while the subject was standing erect on the floor. Baropodograms were recorded before, immediately thereafter, then 15 days and 2 months later. Differences between baropodogram indices were subjected to one-way anova. Electrical abductor hallucis muscle stimulation induced, on the stimulation side, a post-contraction state easily detected on baropodograms as the increased plantar pressure on the anterior-medial part of the sole, and lateral displacements of the anterior maximal pressure point and the foot thrust center. These mechanical signs, consistent with foot inversion, induce external rotation of the leg and pelvic rotation on the stimulated side, leading to contralateral plantar-pressure changes: decreased maximal pressure point and thrust in the posterior part of the footprint and lateral displacement of the foot thrust center. Electrical stimulation of the abductor hallucis muscle in the loaded foot induces immediate specific changes in baropodogram indices, some of which persist 2 months later. The mechanical effect of abductor hallucis muscle stimulation (foot inversion) and its post-contraction state could be useful in podiatric and postural rehabilitation.

  4. Interface of data transmission for a transcutaneous communication system using the human body as transmission medium.

    Science.gov (United States)

    Okamoto, Eiji; Kato, Yoshikuni; Seino, Kazuyuki; Mitamura, Yoshinori

    2012-03-01

    We have been developing a new transcutaneous communication system (TCS) that uses the human body as an electrical conductive medium. We studied an interface circuit of the TCS in order to optimize the leading data current into the human body effectively. Two types of LC circuits were examined for the interface circuit, one was an LC series-parallel circuit, and the other was a parallel-connected LC circuit. The LC series-parallel circuit connected to the body could be tuned to a resonant frequency, and the frequency was determined by the values of an external inductor and an external capacitor. Permittivity of the body did not influence the electrical resonance. Connection of the LC series-parallel circuit to the body degraded the quality factor Q because of the conductivity of the body. However, the LC parallel-connected circuit when connected to the body did not indicate electrical resonance. The LC series-parallel circuit restricts a direct current and a low-frequency current to flow into the body; thus, it can prevent a patient from getting a shock. According to the above results, an LC series-parallel circuit is an optimum interface circuit between the TCS and the body for leading data current into the body effectively and safely.

  5. Transcutaneous electrical nerve stimulation (TENS) accelerates cutaneous wound healing and inhibits pro-inflammatory cytokines.

    Science.gov (United States)

    Gürgen, Seren Gülşen; Sayın, Oya; Cetin, Ferihan; Tuç Yücel, Ayşe

    2014-06-01

    The purpose of this study was to evaluate transcutaneous electrical nerve stimulation (TENS) and other common treatment methods used in the process of wound healing in terms of the expression levels of pro-inflammatory cytokines. In the study, 24 female and 24 male adult Wistar-Albino rats were divided into five groups: (1) the non-wounded group having no incision wounds, (2) the control group having incision wounds, (3) the TENS (2 Hz, 15 min) group, (4) the physiological saline (PS) group and (5) the povidone iodine (PI) group. In the skin sections, interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were assessed with enzyme-linked immunosorbent assay and immunohistochemical methods. In the non-wounded group, the expression of IL-1β, IL-6, and TNF-α signaling molecules was weaker in the whole tissue; however, in the control group, significant inflammatory response occurred, and strong cytokine expression was observed in the dermis, granulation tissue, hair follicles, and sebaceous glands (P TENS group, the decrease in TNF-α, IL-1β, and IL-6 immunoreaction in the skin was significant compared to the other forms of treatment (P TENS group suggest that TENS shortened the healing process by inhibating the inflammation phase.

  6. Transcutaneous electrical nerve stimulation (TENS) for pain control after vaginal delivery and cesarean section.

    Science.gov (United States)

    Kayman-Kose, Seda; Arioz, Dagistan Tolga; Toktas, Hasan; Koken, Gulengul; Kanat-Pektas, Mine; Kose, Mesut; Yilmazer, Mehmet

    2014-10-01

    The present study aims to determine the efficiency and reliability of transcutaneous electrical nerve stimulation (TENS) in the management of pain related with uterine contractions after vaginal delivery and the pain related with both abdominal incision uterine contractions after cesarean section. A hundred healthy women who underwent cesarean section under general anesthesia were randomly assigned to the placebo group (Group 1) or the TENS group (Group 2), while 100 women who delivered by vaginal route without episiotomy were randomized into the placebo group (Group 3) or the TENS group (Group 4). The patients in Group 2 had statistically lower visual analog scale (VAS) and verbal numerical scale (VNS) scores than the patients in Group 1 (p TENS (p = 0.006). The need for analgesics at the eighth hour of vaginal delivery was statistically similar in the patients who were treated with TENS and the patients who received placebo (p = 0.830). TENS is an effective, reliable, practical and easily available modality of treatment for postpartum pain.

  7. Anti-stress effects of transcutaneous electrical nerve stimulation (TENS) on colonic motility in rats.

    Science.gov (United States)

    Yoshimoto, Sazu; Babygirija, Reji; Dobner, Anthony; Ludwig, Kirk; Takahashi, Toku

    2012-05-01

    Disorders of colonic motility may contribute to symptoms in patients with irritable bowel syndrome (IBS), and stress is widely believed to play a major role in developing IBS. Stress increases corticotropin releasing factor (CRF) of the hypothalamus, resulting in acceleration of colonic transit in rodents. In contrast, hypothalamic oxytocin (OXT) has an anti-stress effect via inhibiting CRF expression and hypothalamic-pituitary-adrenal axis activity. Although transcutaneous electrical nerve stimulation (TENS) and acupuncture have been shown to have anti-stress effects, the mechanism of the beneficial effects remains unknown. We tested the hypothesis that TENS upregulates hypothalamic OXT expression resulting in reduced CRF expression and restoration of colonic dysmotility in response to chronic stress. Male SD rats received different types of stressors for seven consecutive days (chronic heterotypic stress). TENS was applied to the bilateral hind limbs every other day before stress loading. Another group of rats did not receive TENS treatment. TENS significantly attenuated accelerated colonic transit induced by chronic heterotypic stress, which was antagonized by a central injection of an OXT antagonist. Immunohistochemical study showed that TENS increased OXT expression and decreased CRF expression at the paraventricular nucleus (PVN) following chronic heterotypic stress. It is suggested that TENS upregulates hypothalamic OXT expression which acts as an anti-stressor agent and mediates restored colonic dysmotility following chronic stress. TENS may be useful to treat gastrointestinal symptoms associated with stress.

  8. Assessing the effects of transcutaneous electrical nerve stimulation (TENS) in post-thoracotomy analgesia.

    Science.gov (United States)

    Ferreira, Fabiana Cristina; Issy, Adriana Machado; Sakata, Rioko Kimiko

    2011-01-01

    Transcutaneous electrical nerve stimulation (TENS) is commonly used to treat musculoskeletal pain, but it may also be indicated for postoperative analgesia. The objective of this study was to evaluate the analgesic effects of TENS on post-thoracotomy. Thirty patients between 18 and 60 years of age undergoing thoracotomy for lung cancer resection on the second postoperative day were included in this study. Patients were divided into two groups (G1 and G2). G1 patients were treated with TENS; and in G2 (without TENS) electrodes were placed but the equipment was not turned on. TENS was maintained for one hour. The visual analogue scale was used to evaluate the analgesic effects on three moments: before TENS (M0), immediately after TENS (M1), and one hour later (M2), with the patient at rest, elevation of the upper limbs, change in decubitus, and coughing. The intensity of pain at rest was higher in G2 immediately after TENS, but not one hour after the procedure. There was no difference between both groups with elevation of the upper limbs, decubitus change, and coughing. With the use of TENS for one hour on the second post-thoracotomy day in patients who received fentanyl (50 μg) associated with bupivacaine (5 mL), a reduction in pain intensity was observed at rest immediately after TENS; with elevation of the upper limbs, change in decubitus, and coughing, a reduction in pain severity was not observed. Copyright © 2011 Elsevier Editora Ltda. All rights reserved.

  9. Antihypertensive effect of low-frequency transcutaneous electrical nerve stimulation (TENS) in comparison with drug treatment.

    Science.gov (United States)

    Silverdal, Jonas; Mourtzinis, Georgios; Stener-Victorin, Elisabet; Mannheimer, Clas; Manhem, Karin

    2012-10-01

    Hypertension is a major risk factor for vascular disease, yet blood pressure (BP) control is unsatisfactory low, partly due to side-effects. Transcutaneous electrical nerve stimulation (TENS) is well tolerated and studies have demonstrated BP reduction. In this study, we compared the BP lowering effect of 2.5 mg felodipin once daily with 30 min of bidaily low-frequency TENS in 32 adult hypertensive subjects (mean office BP 152.7/90.0 mmHg) in a randomized, crossover design. Office BP and 24-h ambulatory BP monitoring (ABPM) were performed at baseline and at the end of each 4-week treatment and washout period. Felodipin reduced office BP by 10/6 mmHg (p TENS reduced office BP by 5/1.5 mmHg (p TENS washout, BP was further reduced and significantly lower than at baseline, but at levels similar to BP after felodipin washout and therefore reasonably caused by factors other than the treatment per se. ABPM revealed a significant systolic reduction of 3 mmHg by felodipin, but no significant changes were noted after TENS. We conclude that our study does not present any solid evidence of BP reduction of TENS.

  10. Effects of transcutaneous electrical nerve stimulation (TENS) on proinflammatory cytokines: protocol for systematic review.

    Science.gov (United States)

    Almeida, Tábata Cristina do Carmo; Figueiredo, Francisco Winter Dos Santos; Barbosa Filho, Valter Cordeiro; de Abreu, Luiz Carlos; Fonseca, Fernando Luiz Affonso; Adami, Fernando

    2017-07-11

    Pain reduction can be achieved by lowering proinflammatory cytokine levels in the blood. Transcutaneous electrical nerve stimulation (TENS) is a non-invasive physiotherapeutic resource for pain management, but evidence on the effectiveness of this device at reducing proinflammatory cytokines in the blood is unclear. This study systematically reviews the literature on the effect of TENS on proinflammatory cytokines. A systematic review protocol was developed based on searches of articles in six electronic databases and references of retrieved articles, contact with authors, and repositories of clinical trials. Eligibility criteria: publication in peer-reviewed journals, randomized clinical trials, use of TENS in the experimental group, and pre- and post-measurements of proinflammatory cytokines in the blood. Selection of the studies and extraction of the data will be carried out by two reviewers independently. Characteristics of the study, participants, interventions and outcomes were extracted and described. Assessments were performed on the risk of bias, level of evidence and the size of the intervention effect in the studies, according to GRADE guidelines and the Cochrane Handbook for Systematic Reviews. Clinical and statistical assessments compared the effects of the interventions (meta-analysis), taking into consideration any influencing characteristics of the studies (e.g., methods and application sites). We anticipate that this review will strengthen evidence-based knowledge of the effect of TENS on proinflammatory cytokines and, as a result, direct new studies to benefit patients with specific pathologies. PROSPERO, CRD42017060379 .

  11. A Prospective Comparison of Transcutaneous and Serum Bilirubin Within Brief Time Intervals.

    Science.gov (United States)

    Jones, Denise F; McRea, Abigail R; Knowles, James D; Lin, Feng-Chang; Burnette, Erin; Reller, Lara A; Lohr, Jacob A

    2017-10-01

    The American Academy of Pediatrics recommends screening newborns ≥35 weeks' gestation with total serum bilirubin (TSB) or transcutaneous bilirubin (TcB) to detect hyperbilirubinemia. Retrospective studies show TcB measurements strongly correlate with TSB; however, few prospective trials document this relationship. Furthermore, Dräger's newest TcB instrument, JM-105, remains unstudied in the United States. We measure TcB on foreheads and sternums of newborns using JM-105 and Bilichek devices within 30 minutes of TSB measurement. We find best overall TcB/TSB correlation with JM-105 on the sternum (mean TcB-TSB difference: -0.21 ± 1.15 mg/dL). Correlations between paired measurements for TcB on the sternum using JM-105 were 0.93 for all TSB levels (n = 178), 0.82 for TSB > 10 (n = 19), 0.69 for TSB > 12 (n = 11), and 0.52 for TSB > 15 (n = 6). TcB accuracy via JM-105 on the sternum significantly differed among races ( P < .001). For 5% of paired measurements, TcB with JM-105 on the sternum underestimated TSB by ≥2 mg/dL, and for <1% by ≥3 mg/dL.

  12. A somatotopic bidirectional hand prosthesis with transcutaneous electrical nerve stimulation based sensory feedback.

    Science.gov (United States)

    D'Anna, Edoardo; Petrini, Francesco M; Artoni, Fiorenzo; Popovic, Igor; Simanić, Igor; Raspopovic, Stanisa; Micera, Silvestro

    2017-09-07

    According to amputees, sensory feedback is amongst the most important features lacking from commercial prostheses. Although restoration of touch by means of implantable neural interfaces has been achieved, these approaches require surgical interventions, and their long-term usability still needs to be fully investigated. Here, we developed a non-invasive alternative which maintains some of the advantages of invasive approaches, such as a somatotopic sensory restitution scheme. We used transcutaneous electrical nerve stimulation (TENS) to induce referred sensations to the phantom hand of amputees. These sensations were characterized in four amputees over two weeks. Although the induced sensation was often paresthesia, the location corresponded to parts of the innervation regions of the median and ulnar nerves, and electroencephalographic (EEG) recordings confirmed the presence of appropriate responses in relevant cortical areas. Using these sensations as feedback during bidirectional prosthesis control, the patients were able to perform several functional tasks that would not be possible otherwise, such as applying one of three levels of force on an external sensor. Performance during these tasks was high, suggesting that this approach could be a viable alternative to the more invasive solutions, offering a trade-off between the quality of the sensation, and the invasiveness of the intervention.

  13. Sound Localization in Patients With Congenital Unilateral Conductive Hearing Loss With a Transcutaneous Bone Conduction Implant.

    Science.gov (United States)

    Vyskocil, Erich; Liepins, Rudolfs; Kaider, Alexandra; Blineder, Michaela; Hamzavi, Sasan

    2017-03-01

    There is no consensus regarding the benefit of implantable hearing aids in congenital unilateral conductive hearing loss (UCHL). This study aimed to measure sound source localization performance in patients with congenital UCHL and contralateral normal hearing who received a new bone conduction implant. Evaluation of within-subject performance differences for sound source localization in a horizontal plane. Tertiary referral center. Five patients with atresia of the external auditory canal and contralateral normal hearing implanted with transcutaneous bone conduction implant at the Medical University of Vienna were tested. Activated/deactivated implant. Sound source localization test; localization performance quantified using the root mean square (RMS) error. Sound source localization ability was highly variable among individual subjects, with RMS errors ranging from 21 to 40 degrees. Horizontal plane localization performance in aided conditions showed statistically significant improvement compared with the unaided conditions, with RMS errors ranging from 17 to 27 degrees. The mean RMS error decreased by a factor of 0.71 (p conduction implant. Some patients with congenital UCHL might be capable of developing improved horizontal plane localization abilities with the binaural cues provided by this device.

  14. Laser Doppler Flowmetry and Transcutaneous Oximetry in Chronic Skin Ulcers: A Comparative Evaluation.

    Science.gov (United States)

    Raposio, Edoardo; Bertozzi, Nicolò; Moretti, Rebecca; Grignaffini, Eugenio; Grieco, Michele P

    2017-07-01

    Laser Doppler Flowmetry (LDF) and transcutaneous oximetry (TcpO2) are established methods for investigating cutaneous perfusion. To date, no study previously performed has compared data obtained from these 2 methodologies in cases of chronic cutaneous ulcers. Laser Doppler Flowmetry and TcpO2 were performed in 25 consecutive outpatients with chronic lower limb ulcers (group A, experimental; 9 women and 16 men; mean age 67 years [range, 52-81 years]) and 25 age- and sex-matched healthy control subjects (group B, control) enrolled for the study. Ulcer aetiologies included 12 peripheral arterial occlusive disease, 9 chronic venous insufficiencies, and 4 pressure ulcers. Data were analyzed with Shapiro-Wilk and Wilcoxon-Mann-Whitney tests. A statistically significant difference (P < .05) was found between LDF values of the 2 groups. No statistically significant differences were found between the 2 groups regarding the TcpO2 measurements. The data confirmed the soundness of LDF while investigating local perfusion in patients with chronic cutaneous ulcers. The same diagnostic accuracy was not obtained by means of TcpO2.

  15. Transcutaneous vagus nerve stimulation (tVNS) enhances conflict-triggered adjustment of cognitive control.

    Science.gov (United States)

    Fischer, Rico; Ventura-Bort, Carlos; Hamm, Alfons; Weymar, Mathias

    2018-04-24

    Response conflicts play a prominent role in the flexible adaptation of behavior as they represent context-signals that indicate the necessity for the recruitment of cognitive control. Previous studies have highlighted the functional roles of the affectively aversive and arousing quality of the conflict signal in triggering the adaptation process. To further test this potential link with arousal, participants performed a response conflict task in two separate sessions with either transcutaneous vagus nerve stimulation (tVNS), which is assumed to activate the locus coeruleus-noradrenaline (LC-NE) system, or with neutral sham stimulation. In both sessions the N2 and P3 event-related potentials (ERP) were assessed. In line with previous findings, conflict interference, the N2 and P3 amplitude were reduced after conflict. Most importantly, this adaptation to conflict was enhanced under tVNS compared to sham stimulation for conflict interference and the N2 amplitude. No effect of tVNS on the P3 component was found. These findings suggest that tVNS increases behavioral and electrophysiological markers of adaptation to conflict. Results are discussed in the context of the potentially underlying LC-NE and other neuromodulatory (e.g., GABA) systems. The present findings add important pieces to the understanding of the neurophysiological mechanisms of conflict-triggered adjustment of cognitive control.

  16. Molybdenum coated SU-8 microneedle electrodes for transcutaneous electrical nerve stimulation.

    Science.gov (United States)

    Soltanzadeh, Ramin; Afsharipour, Elnaz; Shafai, Cyrus; Anssari, Neda; Mansouri, Behzad; Moussavi, Zahra

    2017-11-21

    Electrophysiological devices are connected to the body through electrodes. In some applications, such as nerve stimulation, it is needed to minimally pierce the skin and reach the underneath layers to bypass the impedance of the first layer called stratum corneum. In this study, we have designed and fabricated surface microneedle electrodes for applications such as electrical peripheral nerve stimulation. We used molybdenum for microneedle fabrication, which is a biocompatible metal; it was used for the conductive layer of the needle array. To evaluate the performance of the fabricated electrodes, they were compared with the conventional surface electrodes in nerve conduction velocity experiment. The recorded signals showed a much lower contact resistance and higher bandwidth in low frequencies for the fabricated microneedle electrodes compared to those of the conventional electrodes. These results indicate the electrode-tissue interface capacitance and charge transfer resistance have been increased in our designed electrodes, while the contact resistance decreased. These changes will lead to less harmful Faradaic current passing through the tissue during stimulation in different frequencies. We also compared the designed microneedle electrodes with conventional ones by a 3-dimensional finite element simulation. The results demonstrated that the current density in the deep layers of the skin and the directivity toward a target nerve for microneedle electrodes were much more than those for the conventional ones. Therefore, the designed electrodes are much more efficient than the conventional electrodes for superficial transcutaneous nerve stimulation purposes.

  17. Development of Novel Faster-Dissolving Microneedle Patches for Transcutaneous Vaccine Delivery.

    Science.gov (United States)

    Ono, Akihiko; Ito, Sayami; Sakagami, Shun; Asada, Hideo; Saito, Mio; Quan, Ying-Shu; Kamiyama, Fumio; Hirobe, Sachiko; Okada, Naoki

    2017-08-03

    Microneedle (MN) patches are promising for transcutaneous vaccination because they enable vaccine antigens to physically penetrate the stratum corneum via low-invasive skin puncturing, and to be effectively delivered to antigen-presenting cells in the skin. In second-generation MN patches, the dissolving MNs release the loaded vaccine antigen into the skin. To shorten skin application time for clinical practice, this study aims to develop novel faster-dissolving MNs. We designed two types of MNs made from a single thickening agent, carboxymethylcellulose (CMC) or hyaluronan (HN). Both CMC-MN and HN-MN completely dissolved in rat skin after a 5-min application. In pre-clinical studies, both MNs could demonstrably increase antigen-specific IgG levels after vaccination and prolong antigen deposition compared with conventional injections, and deliver antigens into resected human dermal tissue. In clinical research, we demonstrated that both MNs could reliably and safely puncture human skin without any significant skin irritation from transepidermal water loss measurements and ICDRG (International Contact Dermatitis Research Group) evaluation results.

  18. A combined transcutaneous PO2-PCO2 electrode with electrochemical HCO3- stabilization.

    Science.gov (United States)

    Severinghaus, J W

    1981-10-01

    Combined transcutaneous PO2-PCO2 electrodes are described in which the interaction between the two electrodes due to OH- production at the O2 cathode has been eliminated. An anode of either anodized aluminum or platinum has been driven at a current equal to cathode current to force stoichiometric consumption of OH- at its rate of production. The AgCl reference electrode operates at zero current. O2 sensitivity was not significantly altered by electrolyte pH variation from 6.7 to 9.0 with variations by PCO2. These electrodes have been found stable both with and without spacers, and with electrolytes dissolved in 50-100% ethylene glycol. In 22 anesthetized patients, with electrode temperature of 43 degrees C (s refers to skin surface, a to arterial blood); PsO2 = 0.52PaO2 + 15 (range 54-300) (r = 0.66; Sy . x = 29.6; n = 46); and PsCO2 = 1.39PaCO2 + 2.1 (range 24-98) (r = 0.99; Sy . x = 2.28; n = 48).

  19. A Meta-Analysis of Transcutaneous Electrical Nerve Stimulation for Chronic Low Back Pain.

    Science.gov (United States)

    Jauregui, Julio J; Cherian, Jeffrey J; Gwam, Chukwuweike U; Chughtai, Morad; Mistry, Jaydev B; Elmallah, Randa K; Harwin, Steven F; Bhave, Anil; Mont, Michael A

    2016-04-01

    Transcutaneous electrical nerve stimulation (TENS) may provide a safe alternative to current side-effect-heavy narcotics and anti-inflammatories utilized in chronic low back pain. Therefore, we performed a meta-analysis to evaluate the efficacy of TENS for the treatment of chronic low back pain. We included randomized controlled trials (RCTs), cohort studies, and randomized crossover studies on TENS for the management of low back pain. We utilized a visual analogue scale (VAS) for pain as our primary outcome. Effectiveness of treatment was quantified using improvement in outcome scores for each study. Of the studies that met the criteria, 13 allowed for calculation of weighted mean differences in pain reduction. We used a random model effect to evaluate changes in pain produced by the intervention. Included were nine level I and four level II, encompassing 267 patients (39% male) who had a mean follow-up of seven weeks (range; 2 to 24 weeks). The mean duration of treatment was six weeks (range; 2 to 24 weeks). The standardized mean difference in pain from pre- to post-treatment for TENS was 0.844, which demonstrated significant improvement of TENS on pain reduction. When subdividing treatment duration, patients that were treated for pain, while those treated for > 5 weeks did not. Treatment of chronic low back pain with TENS demonstrated significant pain reduction. The application of TENS may lead to less pain medication usage and should be incorporated into the treatment armamentarium for chronic low back pain.

  20. Transcutaneous electrical nerve stimulation reduces acute low back pain during emergency transport.

    Science.gov (United States)

    Bertalanffy, Alexander; Kober, Alexander; Bertalanffy, Petra; Gustorff, Burkhard; Gore, Odette; Adel, Sharam; Hoerauf, Klaus

    2005-07-01

    Patients with acute low back pain may require emergency transport because of pain and immobilization. Transcutaneous electrical nerve stimulation (TENS) is a nonpharmaceutical therapy for patients with low back pain. To evaluate the efficacy of paramedic-administered TENS in patients with acute low back pain during emergency transport. This was a prospective, randomized study involving 74 patients transported to hospital. The patients were randomly assigned to two groups: group 1 (n = 36) was treated with true TENS, while group 2 (n = 36) was treated with sham TENS. The authors recorded pain and anxiety as the main outcome variables using a visual analog scale (VAS). The authors recorded a significant (p pain reduction (mean +/- standard deviation) during transport in group 1 (79.2 +/- 6.5 mm VAS to 48.9 +/- 8.2 mm VAS), whereas pain scores remained unchanged in group 2 (75.9 +/- 16.4 mm VAS and 77.1 +/- 11.2 mm VAS). Similarly, the scores for anxiety were significantly reduced (p TENS was found to be effective and rapid in reducing pain during emergency transport of patients with acute low back pain and should be considered due to its ease of use and lack of side effects in the study population.

  1. Adjusting Pulse Amplitude During Transcutaneous Electrical Nerve Stimulation Does Not Provide Greater Hypoalgesia.

    Science.gov (United States)

    Bergeron-Vézina, Kayla; Filion, Camille; Couture, Chantal; Vallée, Élisabeth; Laroche, Sarah; Léonard, Guillaume

    2018-03-01

    Transcutaneous electrical nerve stimulation (TENS) is an electrotherapeutic modality commonly used in rehabilitation to relieve pain. Adjusting pulse amplitude (intensity) during TENS treatment has been suggested to overcome nerve habituation. However, it is still unclear if this procedure leads to greater hypoalgesia. The aim of this study was to determine if the hypoalgesic effect of TENS is greater when pulse amplitude is adjusted throughout the TENS treatment session in chronic low-back pain patients. Randomized double-blind crossover study. Recruitment and assessment were conducted at the Clinique universitaire de réadaptation de l'Estrie (CURE) of the Faculty of Medicine and Health Sciences of the Université de Sherbrooke. Twenty-one volunteers with chronic low-back pain were enrolled and completed this investigation. Each patient received two high-frequency TENS treatments on two separate sessions: (1) with adjustment of pulse amplitude and (2) without pulse amplitude adjustment. Pain intensity and unpleasantness were assessed before, during, and after TENS application with a 10 cm visual analog scale. Both TENS conditions (with and without adjustment of intensity) decreased pain intensity and unpleasantness when compared with baseline. No difference was observed between the two stimulation conditions for both pain intensity and unpleasantness. The current results suggest that adjustment of pulse amplitude during TENS application does not provide greater hypoalgesia in individuals with chronic low-back pain. Future studies are needed to confirm these findings in other pain populations.

  2. Transcutaneous electrical nerve stimulation: nonparallel antinociceptive effects on chronic clinical pain and acute experimental pain.

    Science.gov (United States)

    Cheing, G L; Hui-Chan, C W

    1999-03-01

    To investigate to what extent a single 60-minute session of transcutaneous electrical nerve stimulation (TENS) would modify chronic clinical pain, acute experimental pain, and the flexion reflex evoked in chronic low back pain patients. Thirty young subjects with chronic low back pain were randomly allocated to two groups, receiving either TENS or placebo stimulation to the lumbosacral region for 60 minutes. The flexion reflex was elicited by an electrical stimulation applied to the subject's right sole and recorded electromyographically from the biceps femoris and the tibialis anterior muscles. Subjective sensation of low back pain and the electrically induced pain were measured by two separate visual analog scales, termed VAS(LBP) and VAS(FR), respectively. Data obtained before, during, and 60 minutes after TENS and placebo stimulations were analyzed using repeated measures ANOVA. The VAS(LBP) score was significantly reduced to 63.1% of the prestimulation value after TENS (pTENS protocol had different degrees of antinociceptive influence on chronic and acute pain in chronic low back pain patients.

  3. Angiotensin-converting Enzyme Inhibition Improves the Effectiveness of Transcutaneous Carbon Dioxide Treatment.

    Science.gov (United States)

    Nemeth, Balazs; Kiss, Istvan; Jencsik, Timea; Peter, Ivan; Kreska, Zita; Koszegi, Tamas; Miseta, Attila; Kustan, Peter; Boncz, Imre; Laczo, Andrea; Ajtay, Zeno

    2017-01-01

    To study the effect of carbon dioxide (CO 2 ) therapy on the nitric oxide (NO) pathway by monitoring plasma asymmetric dimethylarginine (ADMA) concentrations. Forty-seven hypertensive patients who underwent transcutaneous CO 2 therapy were enrolled. Thirty healthy individuals were recruited for the control group. Blood samples were taken one hour before, as well as one hour, 24 hours and 3 weeks after the first CO 2 treatment. Controls did not undergo CO 2 treatment. Plasma ADMA levels were measured by ELISA. ADMA levels decreased significantly one hour after the first CO2 treatment compared to the baseline concentrations (p=0.003). Significantly greater reduction was found among patients in whom angiotensin converting enzyme inhibitors (ACEIs) were administered (p=0.019). The short- and long-term decrease of ADMA levels suggests that CO 2 is not only a vasodilator, but also has a beneficial effect on the NO pathway. ACE inhibition seems to enhance the effect of CO 2 treatment. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  4. Enhancing the soft tissue seal around intraosseous transcutaneous amputation prostheses using silanized fibronectin titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Chimutengwende-Gordon, M; Pendegrass, C; Blunn, G, E-mail: mukai.cg@mac.com [Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science, University College London, Brockley Hill, Stanmore, HA7 4LP (United Kingdom)

    2011-04-15

    The success of intraosseous transcutaneous amputation prostheses (ITAP) relies on achieving a tight seal between the soft tissues and the implant in order to avoid infection. Fibronectin (Fn) may be silanized onto titanium alloy (Ti-6Al-4V) in order to promote soft-tissue attachment. The silanization process includes passivation with sulphuric acid, which alters surface characteristics. This study aimed to improve in vitro fibroblast adhesion to silanized fibronectin (SiFn) titanium alloy by omitting the passivation stage. Additionally, the study assessed the effects of SiFn on in vivo dermal attachment, comparing the results with adsorbed Fn, hydroxyapatite (HA), Fn adsorbed onto HA (HAFn) and uncoated controls. Surface topography was assessed using scanning electron microscopy, profilometry and contact angle measurement. Anti-vinculin antibodies were used to immunolocalize fibroblast adhesion sites. A histological assessment of soft-tissue attachment and cell alignment relative to implants in an in vivo ovine model was performed. Passivation resulted in rougher, more hydrophobic, microcracked surfaces and was associated with poorer fibroblast adhesion than unpassivated controls. SiFn and HAFn surfaces resulted in more favourable cell alignment in vivo, implying that dermal attachment was enhanced. These results suggest that SiFn and HAFn surfaces could be useful in optimizing the soft tissue seal around ITAP.

  5. Dynamic visualization of dendritic cell-antigen interactions in the skin following transcutaneous immunization.

    Directory of Open Access Journals (Sweden)

    Teerawan Rattanapak

    Full Text Available Delivery of vaccines into the skin provides many advantages over traditional parenteral vaccination and is a promising approach due to the abundance of antigen presenting cells (APC residing in the skin including Langerhans cells (LC and dermal dendritic cells (DDC. However, the main obstacle for transcutaneous immunization (TCI is the effective delivery of the vaccine through the stratum corneum (SC barrier to the APC in the deeper skin layers. This study therefore utilized microneedles (MN and a lipid-based colloidal delivery system (cubosomes as a synergistic approach for the delivery of vaccines to APC in the skin. The process of vaccine uptake and recruitment by specific types of skin APC was investigated in real-time over 4 hours in B6.Cg-Tg (Itgax-EYFP 1 Mnz/J mice by two-photon microscopy. Incorporation of the vaccine into a particulate delivery system and the use of MN preferentially increased vaccine antigen uptake by a highly motile subpopulation of skin APC known as CD207⁺ DC. No uptake of antigen or any response to immunisation by LC could be detected.

  6. Preliminary findings of cerebral responses on transcutaneous vagal nerve stimulation on experimental heat pain.

    Science.gov (United States)

    Usichenko, Taras; Laqua, René; Leutzow, Bianca; Lotze, Martin

    2017-02-01

    Transcutaneous vagal nerve stimulation (TVNS) is a promising complementary method of pain relief. However, the neural networks associated with its analgesic effects are still to be elucidated. Therefore, we conducted two functional magnetic resonance imaging (fMRI) sessions, in a randomized order, with twenty healthy subjects who were exposed to experimental heat pain stimulation applied to the right forearm using a Contact Heat-Evoked Potential Stimulator. While in one session TVNS was administered bilaterally to the concha auriculae with maximal, non-painful intensity, the stimulation device was switched off in the other session (placebo condition). Pain thresholds were measured before and after each session. Heat stimulation elicited fMRI activation in cerebral pain processing regions. Activation magnitude in the secondary somatosensory cortex, posterior insula, anterior cingulate and caudate nucleus was associated with heat stimulation without TVNS. During TVNS, this association was only seen for the right anterior insula. TVNS decreased fMRI signals in the anterior cingulate cortex in comparison with the placebo condition; however, there was no relevant pain reducing effect over the group as a whole. In contrast, TVNS compared to the placebo condition showed an increased activation in the primary motor cortex, contralateral to the site of heat stimulation, and in the right amygdala. In conclusion, in the protocol used here, TVNS specifically modulated the cerebral response to heat pain, without having a direct effect on pain thresholds.

  7. Implementation of a transcutaneous charger for fully implantable middle ear hearing device.

    Science.gov (United States)

    Lim, H; Yoon, Y; Lee, C; Park, I; Song, B; Cho, J

    2005-01-01

    A transcutaneous charger for the fully implantable middle ear hearing device (F-IMEHD), which can monitor the charging level of battery, has been designed and implemented. In order to recharge the battery of F-IMEHD, the electromagnetic coupling between primary coil at outer body and secondary coil at inner body has been used. Considering the implant condition of the F-IMEHD, the primary coil and the secondary coil have been designed. Using the resonance of LC tank circuit at each coil, transmission efficiency was increased. Since the primary and the secondary coil are magnetically coupled, the current variation of the primary coil is related with the impedance of internal resonant circuit. Using the principle mentioned above, the implanted module could transmit outward the information about charging state of battery or coupling between two coils by the changing internal impedance. As in the demonstrated results of experiment, the implemented charger has supplied the sufficient operating voltage for the implanted battery within about 10 mm distance. And also, it has been confirmed that the implanted module can transmit information outward by control of internal impedance.

  8. Necessary Tension in Marine Risers Tension des colonnes montantes en mer

    Directory of Open Access Journals (Sweden)

    Lubinski A.

    2006-11-01

    Full Text Available The tension governing transverse static and dynamic deflections in a riser is not the actual tension but the so-called « effective tension » The concept of effective tension and effective compression is thoroughly explained, and means for calculating effective forces are given. Numerical examples are worked out for risers whose length is between 152 m (520 ft and 920 m (3020 ft. The reciprocal of maximum bending moment of the vicinity of the hall joint is plotted versus the effective tension of the ball joint. Bending moments used were obtained through use of static and dynamic computer programs applied ta a variety of conditions of wave loading, use or non-use of buoyant moterial sleeves, etc. The most important parameters affecting riser performance are the effective La tension régissant les déflections transversales statiques et dynamiques d'une colonne montante n'est pas la tension réelle mais ce qu'on appelle « la tension effective ». Le concept de tension ou de compression effective est expliqué en détail et la façon de calculer les forces effectives est indiquée dans cet article. Des exemples numériques sont développés pour des colonnes montantes de longueur comprise entre 152 m (520 ft et 920 m (3 020 ft. On a tracé la courbe de l'inverse du moment fléchissant en fonction de la tension effective à l'articulation. Les moments fléchissants utilisés ont été calculés par ordinateur en utilisant des programmes dynamiques et statiques pour des conditions variées d'action des vagues, la colonne montante étant ou non munie de manchettes de flottabilité, etc. Les deux paramètres les plus importants qui affectent le bon comportement d'une colonne montante sont la tension effective et la charge latérale.

  9. Radiosensitization of mouse skin by oxygen and depletion of glutathione

    International Nuclear Information System (INIS)

    Stevens, Graham; Joiner, Michael; Joiner, Barbara; Johns, Helen; Denekamp, Juliana

    1995-01-01

    Purpose: To determine the oxygen enhancement ratio (OER) and shape of the oxygen sensitization curve of mouse foot skin, the extent to which glutathione (GSH) depletion radiosensitized skin, and the dependence of such sensitization on the ambient oxygen tension. Methods and Materials: The feet of WHT mice were irradiated with single doses of 240 kVp x-rays while mice were exposed to carbogen or gases with oxygen/nitrogen mixtures containing 8-100% O 2 . The anoxic response was obtained by occluding the blood supply to the leg of anesthetized mice with a tourniquet, surrounding the foot with nitrogen, and allowing the mice to breathe 10% O 2 . Further experiments were performed to assess the efficacy of this method to obtain an anoxic response. Radiosensitivity of skin was assessed using the acute skin-reaction assay. Glutathione levels were modified using two schedules of dl-buthionine sulphoximine (BSO) and diethylmaleate (DEM), which were considered to produce extensive and intermediate levels of GSH depletion in the skin of the foot during irradiation. Results: Carbogen caused the greatest radiosensitization of skin, with a reproducible enhancement of 2.2 relative to the anoxic response. The OER of 2.2 is lower than other reports for mouse skin. This may indicate that the extremes of oxygenation were not produced, although there was no direct evidence for this. When skin radiosensitivity was plotted against the logarithm of the oxygen tension in the ambient gas, a sigmoid curve with a K value of 17-21% O 2 in the ambient gas was obtained. Depletion of GSH caused minimal radiosensitization when skin was irradiated under anoxic or well-oxygenated conditions. Radiosensitization by GSH depletion was maximal at intermediate oxygen tensions of 10-21% O 2 in the ambient gas. Increasing the extent of GSH depletion led to increasing radiosensitization, with sensitization enhancement ratios of 1.2 and 1.1, respectively, for extensive and intermediate levels of GSH

  10. Assessment and reduction of diaphragmatic tension during hiatal hernia repair.

    Science.gov (United States)

    Bradley, Daniel Davila; Louie, Brian E; Farivar, Alexander S; Wilshire, Candice L; Baik, Peter U; Aye, Ralph W

    2015-04-01

    During hiatal hernia repair there are two vectors of tension: axial and radial. An optimal repair minimizes the tension along these vectors. Radial tension is not easily recognized. There are no simple maneuvers like measuring length that facilitate assessment of radial tension. The aims of this project were to: (1) establish a simple intraoperative method to evaluate baseline tension of the diaphragmatic hiatal muscle closure; and, (2) assess if tension is reduced by relaxing maneuvers and if so, to what degree. Diaphragmatic characteristics and tension were assessed during hiatal hernia repair with a tension gage. We compared tension measured after hiatal dissection and after relaxing maneuvers were performed. Sixty-four patients (29 M:35F) underwent laparoscopic hiatal hernia repair. Baseline hiatal width was 2.84 cm and tension 13.6 dag. There was a positive correlation between hiatal width and tension (r = 0.55) but the strength of association was low (r (2) = 0.31). Four different hiatal shapes (slit, teardrop, "D", and oval) were identified and appear to influence tension and the need for relaxing incision. Tension was reduced by 35.8 % after a left pleurotomy (12 patients); by 46.2 % after a right crural relaxing incision (15 patients); and by 56.1 % if both maneuvers were performed (6 patients). Tension on the diaphragmatic hiatus can be measured with a novel device. There was a limited correlation with width of the hiatal opening. Relaxing maneuvers such as a left pleurotomy or a right crural relaxing incision reduced tension. Longer term follow-up will determine whether outcomes are improved by quantifying and reducing radial tension.

  11. Thermal Analysis of Bending Under Tension Test

    DEFF Research Database (Denmark)

    Ceron, Ermanno; Martins, Paulo A.F.; Bay, Niels

    2014-01-01

    during testing is similar to the one in the production tool. A universal sheet tribo-tester has been developed, which can run multiple tests automatically from coil. This allows emulating the temperature increase as in production. The present work performs finite element analysis of the evolution......The tribological conditions in deep drawing can be simulated in the Bending Under Tension test to evaluate the performance of new lubricants, tool materials, etc. Deep drawing production with automatic handling runs normally at high rate. This implies considerable heating of the tools, which...... sometimes can cause lubricant film breakdown and galling. In order to replicate the production conditions in bending under tension testing it is thus important to control the tool/workpiece interface temperature. This can be done by pre-heating the tool, but it is essential that the interface temperature...

  12. Quantum surface tension in ideal gases

    International Nuclear Information System (INIS)

    Sisman, A.

    2005-01-01

    Due to wave character of atoms, an ideal gas confined in a finite domain exhibits Casimir like size effects. These effects become appreciable in a domain with at least one dimension in the order of micron. On this scale, thermodynamic state functions of an ideal gas become shape and size dependent and some new effects appear. In the literature, only some domains of regular shapes have been considered. In this study, the results are generalized to a domain of an arbitrary shape by using Weyl s conjecture for density of states. It is seen that free energy expression of an ideal Maxwellian gas consists of a classical volume dependent term and also a quantum originated surface dependent term, which causes a quantum surface tension. In a rectangular box filled by an ideal gas and separated by a movable wall into two parts, it is shown that a lateral force appears on the movable wall due to quantum surface tension

  13. Separation anxiety: Stress, tension and cytokinesis

    International Nuclear Information System (INIS)

    Mohan, Krithika; Iglesias, Pablo A.; Robinson, Douglas N.

    2012-01-01

    Cytokinesis, the physical separation of a mother cell into two daughter cells, progresses through a series of well-defined changes in morphology. These changes involve distinct biochemical and mechanical processes. Here, we review the mechanical features of cells during cytokinesis, discussing both the material properties as well as sources of stresses, both active and passive, which lead to the observed changes in morphology. We also describe a mechanosensory feedback control system that regulates protein localization and shape progression during cytokinesis. -- Highlights: ► Cytokinesis progresses through three distinct mechanical phases. ► Cortical tension initially resists deformation of mother cell. ► Late in cytokinesis, cortical tension provides stress, enabling furrow ingression. ► A mechanosensory feedback control system regulates cytokinesis.

  14. Transnasal humidified rapid insufflation ventilatory exchange for oxygenation of children during apnoea: a prospective randomised controlled trial.

    Science.gov (United States)

    Riva, T; Pedersen, T H; Seiler, S; Kasper, N; Theiler, L; Greif, R; Kleine-Brueggeney, M

    2018-03-01

    Transnasal humidified rapid insufflation ventilatory exchange (THRIVE) comprises the administration of heated, humidified, and blended air/oxygen mixtures via nasal cannula at rates of ≥2 litres kg -1  min -1 . The aim of this randomized controlled study was to evaluate the length of the safe apnoea time using THRIVE with two different oxygen concentrations (100% vs 30% oxygen) compared with standard low-flow 100% oxygen administration. Sixty patients, aged 1-6 yr, weighing 10-20 kg, undergoing general anaesthesia for elective surgery, were randomly allocated to receive one of the following oxygen administration methods during apnoea: 1) low-flow 100% oxygen at 0.2 litres kg -1  min -1 ; 2) THRIVE 100% oxygen at 2 litres kg -1  min -1 ; and 3) THRIVE 30% oxygen at 2 litres kg -1  min -1 . Primary outcome was time to desaturation to 95%. Termination criteria included SpO 2 decreased to 95%, transcutaneous CO 2 increased to 65 mmHg, or apnoea time of 10 min. The median (interquartile range) [range] apnoea time was 6.9 (5.7-7.8) [2.8-10.0] min for low-flow 100% oxygen, 7.6 (6.2-9.1) [5.2-10.0] min for THRIVE 100% oxygen, and 3.0 (2.4-3.7) [0.2-5.3] min for THRIVE 30% oxygen. No significant difference was detected between apnoea times with low-flow and THRIVE 100% oxygen administration (P=0.15). THRIVE with 30% oxygen demonstrated significantly shorter apnoea times (Prate of transcutaneous CO 2 increase was 0.57 (0.49-0.63) [0.29-8.92] kPa min -1 without differences between the 3 groups (P=0.25). High-flow 100% oxygen (2 litres kg -1  min -1 ) administered via nasal cannulas did not extend the safe apnoea time for children weighing 10-20 kg compared with low-flow nasal cannula oxygen (0.2 litres kg -1  min -1 ). No ventilatory effect was observed with THRIVE at 2.0 litres kg -1  min -1 . NCT02979067. Copyright © 2017 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.

  15. Tension Tests On Bored Piles In Sand

    DEFF Research Database (Denmark)

    Krabbenhøft, Sven; Clausen, Johan; Damkilde, Lars

    2006-01-01

    The lengths of the bored piles varied from 2 m to 6 m and all were of a diameter of 140 mm. The piles were tested to failure in tension and the load-displacement relations were recorded. The investigation has shown pronounced differences between the load bearing capacities obtained by different...... design methods. The methods proposed by Fleming et al. and Reese & O’Neill seem to produce the best match with the test results....

  16. Surface tension confined liquid cryogen cooler

    Science.gov (United States)

    Castles, Stephen H. (Inventor); Schein, Michael E. (Inventor)

    1989-01-01

    A cryogenic cooler is provided for use in craft such as launch, orbital, and space vehicles subject to substantial vibration, changes in orientation, and weightlessness. The cooler contains a small pore, large free volume, low density material to restrain a cryogen through surface tension effects during launch and zero-g operations and maintains instrumentation within the temperature range of 10 to 140 K. The cooler operation is completely passive, with no inherent vibration or power requirements.

  17. Surface tension of H2O and D2O

    International Nuclear Information System (INIS)

    Vargaftik, N.B.; Voljak, L.D.; Volkov, B.N.

    1975-01-01

    There is a great number of works on surface tension of clean water (H 2 O) at temperatures up to 100 deg C and very few above the boiling point. Works on surface tension of heavy water (D 2 O) are insufficient. A review of works on surface tension of both kinds of water is given

  18. Evaluation of peripheral microcirculation improvement of foot after tarsal tunnel release in diabetic patients by transcutaneous oximetry.

    Science.gov (United States)

    Trignano, Emilio; Fallico, Nefer; Chen, Hung-Chi; Faenza, Mario; Bolognini, Alfonso; Armenti, Andrea; Santanelli Di Pompeo, Fabio; Rubino, Corrado; Campus, Gian Vittorio

    2016-01-01

    According to recent studies, peripheral nerve decompression in diabetic patients seems to not only improve nerve function, but also to increase microcirculation; thus decreasing the incidence of diabetic foot wounds and amputations. However, while the postoperative improvement of nerve function is demonstrated, the changes in peripheral microcirculation have not been demonstrated yet. The aim of this study is to assess the degree of microcirculation improvement of foot after the tarsal tunnel release in the diabetic patients by using transcutaneous oximetry. Twenty diabetic male patients aged between 43 and 72 years old (mean age 61.2 years old) suffering from diabetic peripheral neuropathy with superimposed nerve compression underwent transcutaneous oximetry (PtcO2) before and after tarsal tunnel release by placing an electrode on the skin at the level of the dorsum of the foot. Eight lower extremities presented diabetic foot wound preoperatively. Thirty-six lower extremities underwent surgical release of the tibialis posterior nerve only, whereas four lower extremities underwent the combined release of common peroneal nerve, anterior tibialis nerve, and posterior tibialis nerve. Preoperative values of transcutaneous oximetry were below the critical threshold, that is, lower than 40 mmHg (29.1 ± 5.4 mmHg). PtcO2 values at one month after surgery (45.8 ± 6.4 mmHg) were significantly higher than the preoperative ones (P = 0.01). The results of postoperative increase in PtcO2 values demonstrate that the release of the tarsal tunnel determines a relevant increase in microcirculation in the feet of diabetic patients. © 2015 Wiley Periodicals, Inc.

  19. The value of transcutaneous method of bilirubin measurement in newborn population with the risk of ABO hemolytic disease.

    Science.gov (United States)

    Stoniene, Dalia; Buinauskiene, Jūrate; Markūniene, Egle

    2009-01-01

    OBJECTIVE OF THE STUDY. To evaluate the correlation between total serum bilirubin (TSB) and transcutaneous bilirubin (TcB) levels in newborn infants at risk of ABO hemolytic disease. MATERIAL AND METHODS. During a prospective study, 130 full-term (>or=37 weeks of gestation) newborn infants with diagnosed ABO blood group incompatibility were examined. TSB level was measured at the age of 6 hours; further measurements were performed at 24, 48, and 72 hours following the first measurement. Blood samples were collected from the peripheral veins. In clinical laboratory, total serum bilirubin level was measured using Jendrassik-Grof method. TcB level in the forehead was measured using a noninvasive bilirubinometer BiliCheck (SpectRX Inc, Norcross, GA) according to the manufacturer's instructions within +/-30 min after getting a blood sample. RESULTS. During the study, 387 double tests were performed to measure TSB and TcB levels. TSB level (114.83 [62.85] micromol/L) closely correlated with TcB level (111.51 [61.31] micromol/L) (r=0.92, Por=98 micromol/L, ABO hemolytic disease in newborns may be diagnosed with 100% sensitivity and 98% specificity; positive predictive value was 62% and negative predictive value was 100%. While a newborn's age increases, TcB sensitivity and specificity for diagnosing ABO hemolytic disease decrease. CONCLUSION. While evaluating bilirubin level transcutaneously according to nomograms of serum bilirubin level, the results should be considered with caution, especially for newborns with a risk of ABO hemolytic disease. The hour-specific nomograms of transcutaneous bilirubin level should be used to evaluate hyperbilirubinemia using only a noninvasive method.

  20. Tension-induced binding of semiflexible biopolymers

    International Nuclear Information System (INIS)

    Benetatos, Panayotis; Heydt, Alice von der; Zippelius, Annette

    2014-01-01

    We investigate theoretically the effect of polymer tension on the collective behavior of reversibly binding cross-links. For this purpose, we employ a model of two weakly bending wormlike chains aligned in parallel by a tensile force, with a sequence of inter-chain binding sites regularly spaced along the contours. Reversible cross-links attach and detach at the sites with an affinity controlled by a chemical potential. In a mean-field approach, we calculate the free energy of the system and find the emergence of a free-energy barrier which controls the reversible (un)binding. The tension affects the conformational entropy of the chains which competes with the binding energy of the cross-links. This competition gives rise to a sudden increase in the fraction of bound sites as the tension increases. We show that this transition is related to the cross-over between weak and strong localization of a directed polymer in a pinning potential. The cross-over to the strongly bound state can be interpreted as a mechanism for force-stiffening which exceeds the capabilities of single-chain elasticity and thus available only to reversibly cross-linked polymers. (paper)

  1. Generalized surface tension bounds in vacuum decay

    Science.gov (United States)

    Masoumi, Ali; Paban, Sonia; Weinberg, Erick J.

    2018-02-01

    Coleman and De Luccia (CDL) showed that gravitational effects can prevent the decay by bubble nucleation of a Minkowski or AdS false vacuum. In their thin-wall approximation this happens whenever the surface tension in the bubble wall exceeds an upper bound proportional to the difference of the square roots of the true and false vacuum energy densities. Recently it was shown that there is another type of thin-wall regime that differs from that of CDL in that the radius of curvature grows substantially as one moves through the wall. Not only does the CDL derivation of the bound fail in this case, but also its very formulation becomes ambiguous because the surface tension is not well defined. We propose a definition of the surface tension and show that it obeys a bound similar in form to that of the CDL case. We then show that both thin-wall bounds are special cases of a more general bound that is satisfied for all bounce solutions with Minkowski or AdS false vacua. We discuss the limit where the parameters of the theory attain critical values and the bound is saturated. The bounce solution then disappears and a static planar domain wall solution appears in its stead. The scalar field potential then is of the form expected in supergravity, but this is only guaranteed along the trajectory in field space traced out by the bounce.

  2. Tension-induced binding of semiflexible biopolymers

    Science.gov (United States)

    Benetatos, Panayotis; von der Heydt, Alice; Zippelius, Annette

    2015-03-01

    We investigate theoretically the effect of polymer tension on the collective behaviour of reversible cross-links. We use a model of two parallel-aligned, weakly-bending wormlike chains with a regularly spaced sequence of binding sites subjected to a tensile force. Reversible cross-links attach and detach at the binding sites with an affinity controlled by a chemical potential. In a mean-field approach, we calculate the free energy of the system and we show the emergence of a free energy barrier which controls the reversible (un)binding. The tension affects the conformational entropy of the chains which competes with the binding energy of the cross-links. This competition gives rise to a sudden increase in the fraction of bound sites as the polymer tension increases. The force-induced first-order transition in the number of cross-links implies a sudden force-induced stiffening of the effective stretching modulus of the polymers. This mechanism may be relevant to the formation and stress-induced strengthening of stress fibers in the cytoskeleton. We acknowledge support by the Deutsche Forschungsgemeinschaft (DFG) via grant SFB-937/A1.

  3. Detection of low tension cosmic superstrings

    Science.gov (United States)

    Chernoff, David F.; Tye, S.-H. Henry

    2018-05-01

    Cosmic superstrings of string theory differ from conventional cosmic strings of field theory. We review how the physical and cosmological properties of the macroscopic string loops influence experimental searches for these relics from the epoch of inflation. The universe's average density of cosmic superstrings can easily exceed that of conventional cosmic strings having the same tension by two or more orders of magnitude. The cosmological behavior of the remnant superstring loops is qualitatively distinct because the string tension is exponentially smaller than the string scale in flux compactifications in string theory. Low tension superstring loops live longer, experience less recoil (rocket effect from the emission of gravitational radiation) and tend to cluster like dark matter in galaxies. Clustering enhances the string loop density with respect to the cosmological average in collapsed structures in the universe. The enhancement at the Sun's position is ~ 105. We develop a model encapsulating the leading order string theory effects, the current understanding of the string network loop production and the influence of cosmological structure formation suitable for forecasting the detection of superstring loops via optical microlensing, gravitational wave bursts and fast radio bursts. We evaluate the detection rate of bursts from cusps and kinks by LIGO- and LISA-like experiments. Clustering dominates rates for G μ 10‑14.2 (LIGO cusp), G μ>10‑15 (LISA cusp) and G μ>10‑ 14.1 (LISA kink).

  4. Macrophages Under Low Oxygen Culture Conditions Respond to Ion Parametric Resonance Magnetic Fields

    Science.gov (United States)

    Macrophages, when entering inflamed tissue, encounter low oxygen tension due to the impairment of blood supply and/or the massive infiltration of cells that consume oxygen. Previously, we showed that such macrophages release more bacteriotoxic hydrogen peroxide (H202) when expose...

  5. High- and low-frequency transcutaneous electrical nerve stimulation does not reduce experimental pain in elderly individuals

    OpenAIRE

    Bergeron-V?zina, Kayla; Corriveau, H?l?ne; Martel, Marylie; Harvey, Marie-Philippe; L?onard, Guillaume

    2015-01-01

    Abstract Despite its widespread clinical use, the efficacy of transcutaneous electrical nerve stimulation (TENS) remains poorly documented in elderly individuals. In this randomized, double-blind crossover study, we compared the efficacy of high-frequency (HF), low-frequency (LF), and placebo (P) TENS in a group of 15 elderly adults (mean age: 67 ? 5 years). The effect of HF-, LF-, and P-TENS was also evaluated in a group of 15 young individuals (26 ? 5 years; same study design) to validate t...

  6. Fixed-site high-frequency transcutaneous electrical nerve stimulation for treatment of chronic low back and lower extremity pain

    Directory of Open Access Journals (Sweden)

    Gozani SN

    2016-06-01

    Full Text Available Shai N Gozani NeuroMetrix, Inc., Waltham, MA, USA Objective: The objective of this study was to determine if fixed-site high-frequency transcutaneous electrical nerve stimulation (FS-TENS is effective in treating chronic low back and lower extremity pain. Background: Transcutaneous electrical nerve stimulation is widely used for treatment of chronic pain. General-purpose transcutaneous electrical nerve stimulation devices are designed for stimulation anywhere on the body and often cannot be used while the user is active or sleeping. FS-TENS devices are designed for placement at a pre-determined location, which enables development of a wearable device for use over extended time periods. Methods: Study participants with chronic low back and/or lower extremity pain self-administered an FS-TENS device for 60 days. Baseline, 30-, and 60-day follow-up data were obtained through an online questionnaire. The primary outcome measure was the patient global impression of change. Pain intensity and interference were assessed using the Brief Pain Inventory. Changes in use of concomitant pain medications were evaluated with a single-item global self-rating. Results: One hundred and thirty participants were enrolled, with 88 completing the 60-day follow-up questionnaire. Most participants (73.9% were 50 years of age or older. At baseline, low back pain was identified by 85.3%, lower extremity pain by 71.6%, and upper extremity pain by 62.5%. Participants reported widespread pain, at baseline, with a mean of 3.4 (standard deviation 1.1 pain sites. At the 60-day follow-up, 80.7% of participants reported that their chronic pain had improved and they were classified as responders. Baseline characteristics did not differentiate non-responders from responders. There were numerical trends toward reduced pain interference with walking ability and sleep, and greater pain relief in responders. There was a large difference in use of concomitant pain medications, with 80

  7. The effects of transcutaneous electrical nerve stimulation on joint position sense in patients with knee joint osteoarthritis.

    Science.gov (United States)

    Shirazi, Zahra Rojhani; Shafaee, Razieh; Abbasi, Leila

    2014-10-01

    To study the effects of transcutaneous electrical nerve stimulation (TENS) on joint position sense (JPS) in knee osteoarthritis (OA) subjects. Thirty subjects with knee OA (40-60 years old) using non-random sampling participated in this study. In order to evaluate the absolute error of repositioning of the knee joint, Qualysis Track Manager system was used and sensory electrical stimulation was applied through the TENS device. The mean errors in repositioning of the joint, in two position of the knee joint with 20 and 60 degree angle, after applying the TENS was significantly decreased (p knee OA could improve JPS in these subjects.

  8. CT-assisted transcutaneous interstitial implantation of thoracic tumors: Early experience

    International Nuclear Information System (INIS)

    Heelan, R.T.; Hilaris, B.S.; Anderson, L.; Caravelli, J.F.; Nori, D.; Martini, N.; Watson, R.C.; Linares, L.

    1986-01-01

    The authors have transcutaneously implanted I-125 radioactive seeds in six patients with thoracic tumors (three with lung cancer; three with metastases) to determine the feasibility of this procedure. In four patients the thoracic tumors were localized without evidence of distant metastases, but these patients were not candidates for resection because of chronic pulmonary disease. Tumor volume was measured on CT scans (with sagittal and coronal reconstructions) and the required number of seeds was determined based on tumor volume. Between 6 and 11 needles were placed in the tumor and the seeds were implanted as the needle was withdrawn. Between 40 and 60 seeds were implanted in each patient, under local anesthesia. In this preliminary series all patients were found to have tumor attached to pleura. Four of the six patients underwent implantation during a day-time admission to the institution's Adult Day Hospital. No patient suffered any complication as a result of the procedure. Four patients experienced a symptomatic relief of pain and a decrease in size of tumor bulk (local control). Two patients eventually exhibited renewed tumor growth in the edges of the implanted mass after 6 months; the authors plan to supplement future implantations with external radiation therapy. One patient underwent implantation after local recurrence of tumor, returned to work the day following the procedure, and is without evidence of local recurrence 18 months later. They are encouraged by these preliminary results, for several reasons: the lack of morbidity, the achievement of local control of tumor while avoiding surgery and its potential complications, and avoidance of hospital stay (with consequent financial savings). The intent is to expand this series to include patients with lung tumors not attached to pleura

  9. Treatment of Idiopathic Chronic Orchialgia with Transcutaneous Electrical Nerve Stimulation (TENS:A Preliminary Result

    Directory of Open Access Journals (Sweden)

    Ekrem Akdeniz

    2016-01-01

    Full Text Available Purpose: Unilateral or bilateral testicular pain lasting more than 3 months is called as chronic orchialgia. Aproximately 25-50% of chronic orchialgia is idiopatic origin. This study aimed the effectiveness of Transcutaneous Electrical Nerve Stimulation (TENS therapy due to Idiopathic Chronic Orchialgia (ICO. Methods: Five patients were included into this study with ICO that diagnosed with physical examination, urine analyses, urinary system x-ray film, and scrotal doppler ultrasound. Medical history revealed that multiple conservative therapy attempts failed to alleviate the pain. Two of the patients had right sided ICO. Traditional TENS device is placed to the most painful points. TENS applied 3 times in a week with duration 30 minutes for 4 weeks. Before and after TENS application, patients were evaluated by using Visual Analog Scale (VAS at first and third months. Results: Median age of patients was 26.20±2.38 (22-30. Mean VAS value was 6.52 ± 0.89 before the procedure. After 1 month VAS value was 3.82 ± 0.83 (p0.05. None of the patients needed any analgesics after during the one month. No complications, hyperemia or hypoesthesia of the scrotal or penile skin, occurred after the procedure. Conclusion: TENS reduces pain by increasing endorphin release in the spinal cord dorsal horn. TENS is very effective method for first 1 month in patients with ICO but its effect reduces by the time. There is no standard therapeutic protocol for idiopathic chronic orchialgia. Therefore TENS may be an alternative for patients who do not benefit from medical therapy and do not want invasive procedures. Short-term use of TENS and low number of the patients are the limitations of this study. Randomized, placebo-controlled, and longer follow-up period studies are needed to better assess the efficacy of TENS for ICO.

  10. Moving Beyond the Brain: Transcutaneous Spinal Direct Current Stimulation in Post-Stroke Aphasia

    Directory of Open Access Journals (Sweden)

    Paola Marangolo

    2017-08-01

    Full Text Available Over the last 20 years, major advances in cognitive neuroscience have clearly shown that the language function is not restricted into the classical language areas but it involves brain regions, which had never previously considered. Indeed, recent lines of evidence have suggested that the processing of words associated to motor schemata, such as action verbs, modulates the activity of the sensorimotor cortex, which, in turn, facilitates its retrieval. To date, no studies have investigated whether the spinal cord, which is functionally connected to the sensorimotor system, might also work as an auxiliary support for language processing. We explored the combined effect of transcutaneous spinal direct current stimulation (tsDCS and language treatment in a randomized double-blind design for the recovery of verbs and nouns in 14 chronic aphasics. During each treatment, each subject received tsDCS (20 min, 2 mA over the thoracic vertebrae (10th vertebra in three different conditions: (1 anodic, (2 cathodic and (3 sham, while performing a verb and noun naming tasks. Each experimental condition was run in five consecutive daily sessions over 3 weeks. Overall, a significant greater improvement in verb naming was found during the anodic condition with respect to the other two conditions, which persisted at 1 week after the end of the treatment. No significant differences were present for noun naming among the three conditions. The hypothesis is advanced that anodic tsDCS might have influenced activity along the ascending somatosensory pathways, ultimately eliciting neurophysiological changes into the sensorimotor areas which, in turn, supported the retrieval of verbs. These results further support the evidence that action words, due to their sensorimotor semantic properties, are partly represented into the sensorimotor cortex. Moreover, they also document, for the first time, that tsDCS enhances verb recovery in chronic aphasia and it may

  11. Moving Beyond the Brain: Transcutaneous Spinal Direct Current Stimulation in Post-Stroke Aphasia

    Science.gov (United States)

    Marangolo, Paola; Fiori, Valentina; Shofany, Jacob; Gili, Tommaso; Caltagirone, Carlo; Cucuzza, Gabriella; Priori, Alberto

    2017-01-01

    Over the last 20 years, major advances in cognitive neuroscience have clearly shown that the language function is not restricted into the classical language areas but it involves brain regions, which had never previously considered. Indeed, recent lines of evidence have suggested that the processing of words associated to motor schemata, such as action verbs, modulates the activity of the sensorimotor cortex, which, in turn, facilitates its retrieval. To date, no studies have investigated whether the spinal cord, which is functionally connected to the sensorimotor system, might also work as an auxiliary support for language processing. We explored the combined effect of transcutaneous spinal direct current stimulation (tsDCS) and language treatment in a randomized double-blind design for the recovery of verbs and nouns in 14 chronic aphasics. During each treatment, each subject received tsDCS (20 min, 2 mA) over the thoracic vertebrae (10th vertebra) in three different conditions: (1) anodic, (2) cathodic and (3) sham, while performing a verb and noun naming tasks. Each experimental condition was run in five consecutive daily sessions over 3 weeks. Overall, a significant greater improvement in verb naming was found during the anodic condition with respect to the other two conditions, which persisted at 1 week after the end of the treatment. No significant differences were present for noun naming among the three conditions. The hypothesis is advanced that anodic tsDCS might have influenced activity along the ascending somatosensory pathways, ultimately eliciting neurophysiological changes into the sensorimotor areas which, in turn, supported the retrieval of verbs. These results further support the evidence that action words, due to their sensorimotor semantic properties, are partly represented into the sensorimotor cortex. Moreover, they also document, for the first time, that tsDCS enhances verb recovery in chronic aphasia and it may represent a

  12. Long-duration transcutaneous electric acupoint stimulation alters small-world brain functional networks.

    Science.gov (United States)

    Zhang, Yue; Jiang, Yin; Glielmi, Christopher B; Li, Longchuan; Hu, Xiaoping; Wang, Xiaoying; Han, Jisheng; Zhang, Jue; Cui, Cailian; Fang, Jing

    2013-09-01

    Acupuncture, which is recognized as an alternative and complementary treatment in Western medicine, has long shown efficiencies in chronic pain relief, drug addiction treatment, stroke rehabilitation and other clinical practices. The neural mechanism underlying acupuncture, however, is still unclear. Many studies have focused on the sustained effects of acupuncture on healthy subjects, yet there are very few on the topological organization of functional networks in the whole brain in response to long-duration acupuncture (longer than 20 min). This paper presents a novel study on the effects of long-duration transcutaneous electric acupoint stimulation (TEAS) on the small-world properties of brain functional networks. Functional magnetic resonance imaging was used to construct brain functional networks of 18 healthy subjects (9 males and 9 females) during the resting state. All subjects received both TEAS and minimal TEAS (MTEAS) and were scanned before and after each stimulation. An altered functional network was found with lower local efficiency and no significant change in global efficiency for healthy subjects after TEAS, while no significant difference was observed after MTEAS. The experiments also showed that the nodal efficiencies in several paralimbic/limbic regions were altered by TEAS, and those in middle frontal gyrus and other regions by MTEAS. To remove the psychological effects and the baseline, we compared the difference between diffTEAS (difference between after and before TEAS) and diffMTEAS (difference between after and before MTEAS). The results showed that the local efficiency was decreased and that the nodal efficiencies in frontal gyrus, orbitofrontal cortex, anterior cingulate gyrus and hippocampus gyrus were changed. Based on those observations, we conclude that long-duration TEAS may modulate the short-range connections of brain functional networks and also the limbic system. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Soft-Tissue-Anchored Transcutaneous Port for Long-Term Percutaneous Transhepatic Biliary Drainage

    International Nuclear Information System (INIS)

    Nyman, Rickard; Ekloef, Hampus; Eriksson, Lars-Gunnar; Karlsson, Britt-Marie; Rasmussen, Ib; Lundgren, Dan; Thomsen, Peter

    2005-01-01

    Purpose. A transcutaneous port (T-port) has been developed allowing easy exchange of a catheter, which was fixed inside the device, using the Seldinger technique. The objective of the study was to test the T-port in patients who had percutaneous transhepatic biliary drainage (PTBD). Methods. The T-port, made of titanium, was implanted using local anesthesia in 11 patients (mean age 65 years, range 52-85 years) with biliary duct obstruction (7 malignant and 4 benign strictures). The subcutaneous part of the T-port consisted of a flange with several perforations allowing ingrowth of connective tissue. The T-port allowed catheter sizes of 10 and 12 Fr. Results. All wounds healed uneventfully and were followed by a stable period without signs of pronounced inflammation or infection. It was easy to open the port and to exchange the drainage tube. The patient's quality of life was considerably improved even though several patients had problems with repeated bile leakage due to frequent recurrent obstructions of the tubes. The ports were implanted for a mean time of 9 months (range 2-21 months). Histologic examination in four cases showed that the port was well integrated into the soft tissue. Tilting of the T-port in two cases led to perforation of the skin by the subcutaneous part of the ports, which were removed after 7 and 8 months. Conclusion. The T-port served as an excellent external access to the biliary ducts. The drainage tubes were well fixed within the ports. The quality of life of the patients was considerably improved. Together with improved aesthetic appearance they found it easier to conduct normal daily activities and personal care. However, the problem of recurrent catheter obstruction remained unsolved

  14. Transcutaneous electrical nerve stimulation and temporary S3 neuromodulation in idiopathic detrusor instability.

    Science.gov (United States)

    Hasan, S T; Robson, W A; Pridie, A K; Neal, D E

    1996-06-01

    We studied the effects of electrical stimulation on idiopathic detrusor instability. Between January 1993 and December 1994, 30 men and 41 women (mean age plus or minus standard deviation 48 +/- 16 years) underwent transcutaneous electrical nerve stimulation (TENS) of the S2-S3 dermatomes, and 13 men and 22 women (mean age 48 +/- 12 years) underwent S3 neuromodulation. Subjective assessment was performed using a diary and symptom score of 0 to 14. Objective outcome was analyzed with urodynamic studies. Mean duration of TENS was 3 +/- 1 weeks (range 2 to 4). Although there were no major complications 31% of the patients reported local skin irritation. The overall urinary symptom scores improved from 10 +/- 2 (range 5 to 14) before the study to 7 +/- 3 (range 1 to 14) during stimulation. Urodynamic analysis revealed significant (p neuromodulation was 6 +/- 1 days (range 4 to 8 days). Four procedures failed due to electrode displacement in 3 cases and procedure intolerance in 1. Hemorrhage from the puncture site occurred in 1 patient. Overall urinary symptom scores were 10 +/- 3 (range 5 to 14) before the study and 5 +/- 2 (range 2 to 10) during stimulation. Although symptomatic relief was more pronounced with S3 neuromodulation, no statistically significant differences were found regarding urinary symptoms compared to TENS. In patients with severe detrusor instability refractory to conservative treatments the use of TENS and S3 neuromodulation produced significant changes in urodynamic parameters and presenting symptoms. Our results appear to justify evaluation with neuromodulatory techniques before definitive surgical intervention in these patients.

  15. Hypoalgesia in response to transcutaneous electrical nerve stimulation (TENS) depends on stimulation intensity.

    Science.gov (United States)

    Moran, Fidelma; Leonard, Tracey; Hawthorne, Stephanie; Hughes, Ciara M; McCrum-Gardner, Evie; Johnson, Mark I; Rakel, Barbara A; Sluka, Kathleen A; Walsh, Deirdre M

    2011-08-01

    Transcutaneous electrical nerve stimulation (TENS) is an electrophysical modality used for pain management. This study investigated the dose response of different TENS intensities on experimentally induced pressure pain. One hundred and thirty TENS naïve healthy individuals (18-64 years old; 65 males, 65 females) were randomly allocated to 5 groups (n = 26 per group): Strong Non Painful TENS; Sensory Threshold TENS; Below Sensory Threshold TENS; No Current Placebo TENS; and Transient Placebo TENS. Active TENS (80 Hz) was applied to the forearm for 30 minutes. Transient Placebo TENS was applied for 42 seconds after which the current amplitude automatically reset to 0 mA. Pressure pain thresholds (PPT) were recorded from 2 points on the hand and forearm before and after TENS to measure hypoalgesia. There were significant differences between groups at both the hand and forearm (ANOVA; P = .005 and .002). At 30 minutes, there was a significant hypoalgesic effect in the Strong Non Painful TENS group compared to: Below Sensory Threshold TENS, No Current Placebo TENS and Transient Placebo TENS groups (P TENS and No Current Placebo TENS groups at the hand (P = .001). There was no significant difference between Strong Non Painful TENS and Sensory Threshold TENS groups. The area under the curve for the changes in PPT significantly correlated with the current amplitude (r(2) = .33, P = .003). These data therefore show that there is a dose-response effect of TENS with the largest effect occurring with the highest current amplitudes. This study shows a dose response for the intensity of TENS for pain relief with the strongest intensities showing the greatest effect; thus, we suggest that TENS intensity should be titrated to achieve the strongest possible intensity to achieve maximum pain relief. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

  16. Dose-specific effects of transcutaneous electrical nerve stimulation (TENS) on experimental pain: a systematic review.

    Science.gov (United States)

    Claydon, Leica S; Chesterton, Linda S; Barlas, Panos; Sim, Julius

    2011-09-01

    To determine the hypoalgesic effects of transcutaneous electrical nerve stimulation (TENS) parameter combinations on experimental models in healthy humans. Searches were performed using the electronic databases Ovid MEDLINE, CINAHL, AMED, and Web of Science (from inception to December 2009). Manual searches of journals and reference lists of retrieved trials were also performed. Randomized controlled trials (RCTs) were included in the review if they compared the hypoalgesic effect of TENS relative with placebo and control, using an experimental pain model in healthy human participants. Two reviewers independently selected the trials, assessed their methodologic quality and extracted data. Forty-three RCTs were eligible for inclusion. A best evidence synthesis revealed: Overall "conflicting" (inconsistent findings in multiple RCTs) evidence of TENS efficacy on experimental pain irrespective of TENS parameters used. Overall intense TENS has "moderate" evidence of efficacy (1 high-quality and 2 low-quality trials). Conventional TENS has overall conflicting evidence of efficacy, this is derived from "strong" evidence of efficacy (generally consistent findings in multiple high-quality RCTs) on pressure pain but strong evidence of inefficacy on other pain models. "Limited" evidence (positive findings from 1 RCT) of hypoalgesia exists for some novel parameters. Low-intensity, low-frequency, local TENS has strong evidence of inefficacy. Inappropriate TENS (using "barely perceptible" intensities) has moderate evidence of inefficacy. The level of hypoalgesic efficacy of TENS is clearly dependent on TENS parameter combination selection (defined in terms of intensity, frequency, and stimulation site) and experimental pain model. Future clinical RCTs may consider these TENS dose responses.

  17. Modification of spasticity by transcutaneous spinal cord stimulation in individuals with incomplete spinal cord injury

    Science.gov (United States)

    Hofstoetter, Ursula S.; McKay, William B.; Tansey, Keith E.; Mayr, Winfried; Kern, Helmut; Minassian, Karen

    2014-01-01

    Context/objective To examine the effects of transcutaneous spinal cord stimulation (tSCS) on lower-limb spasticity. Design Interventional pilot study to produce preliminary data. Setting Department of Physical Medicine and Rehabilitation, Wilhelminenspital, Vienna, Austria. Participants Three subjects with chronic motor-incomplete spinal cord injury (SCI) who could walk ≥10 m. Interventions Two interconnected stimulating skin electrodes (Ø 5 cm) were placed paraspinally at the T11/T12 vertebral levels, and two rectangular electrodes (8 × 13 cm) on the abdomen for the reference. Biphasic 2 ms-width pulses were delivered at 50 Hz for 30 minutes at intensities producing paraesthesias but no motor responses in the lower limbs. Outcome measures The Wartenberg pendulum test and neurological recordings of surface-electromyography (EMG) were used to assess effects on exaggerated reflex excitability. Non-functional co-activation during volitional movement was evaluated. The timed 10-m walk test provided measures of clinical function. Results The index of spasticity derived from the pendulum test changed from 0.8 ± 0.4 pre- to 0.9 ± 0.3 post-stimulation, with an improvement in the subject with the lowest pre-stimulation index. Exaggerated reflex responsiveness was decreased after tSCS across all subjects, with the most profound effect on passive lower-limb movement (pre- to post-tSCS EMG ratio: 0.2 ± 0.1), as was non-functional co-activation during voluntary movement. Gait speed values increased in two subjects by 39%. Conclusion These preliminary results suggest that tSCS, similar to epidurally delivered stimulation, may be used for spasticity control, without negatively impacting residual motor control in incomplete SCI. Further study in a larger population is warranted. PMID:24090290

  18. Transcutaneous spinal direct current stimulation induces lasting fatigue resistance and enhances explosive vertical jump performance

    Science.gov (United States)

    Tate, Rothwelle J.; Conway, Bernard A.

    2017-01-01

    Transcutaneous spinal direct current stimulation (tsDCS) is a non-invasive neuromodulatory intervention that has been shown to modify excitability in spinal and supraspinal circuits in animals and humans. Our objective in this study was to explore the functional neuromodulatory potential of tsDCS by examining its immediate and lasting effects over the repeated performance of a whole body maximal exercise in healthy volunteers. Using a double-blind, randomized, crossover, sham-controlled design we investigated the effects of 15 min of anodal tsDCS on repeated vertical countermovement jump (VCJ) performance at 0, 20, 60, and 180 minutes post-stimulation. Measurements of peak and take-off velocity, vertical displacement, peak power and work done during countermovement and push-off VCJ phases were derived from changes in vertical ground reaction force (12 performance parameters) in 12 healthy participants. The magnitude and direction of change in VCJ performance from pre- to post-stimulation differed significantly between sham and active tsDCS for 7 of the 12 VCJ performance measures (P 0.05). Our original findings demonstrate that one single session of anodal tsDCS in healthy subjects can prevent fatigue and maintain or enhance different aspects of whole body explosive motor power over repeated sets of VCJs performed over a period of three hours. The observed effects are discussed in relation to alterations in central fatigue mechanisms, muscle contraction mode during jump execution and changes in spinal cord excitability. These findings have important implications for power endurance sport performance and for neuromotor rehabilitation. PMID:28379980

  19. Transcutaneous spinal direct current stimulation induces lasting fatigue resistance and enhances explosive vertical jump performance.

    Directory of Open Access Journals (Sweden)

    Helen R Berry

    Full Text Available Transcutaneous spinal direct current stimulation (tsDCS is a non-invasive neuromodulatory intervention that has been shown to modify excitability in spinal and supraspinal circuits in animals and humans. Our objective in this study was to explore the functional neuromodulatory potential of tsDCS by examining its immediate and lasting effects over the repeated performance of a whole body maximal exercise in healthy volunteers. Using a double-blind, randomized, crossover, sham-controlled design we investigated the effects of 15 min of anodal tsDCS on repeated vertical countermovement jump (VCJ performance at 0, 20, 60, and 180 minutes post-stimulation. Measurements of peak and take-off velocity, vertical displacement, peak power and work done during countermovement and push-off VCJ phases were derived from changes in vertical ground reaction force (12 performance parameters in 12 healthy participants. The magnitude and direction of change in VCJ performance from pre- to post-stimulation differed significantly between sham and active tsDCS for 7 of the 12 VCJ performance measures (P 0.05. Our original findings demonstrate that one single session of anodal tsDCS in healthy subjects can prevent fatigue and maintain or enhance different aspects of whole body explosive motor power over repeated sets of VCJs performed over a period of three hours. The observed effects are discussed in relation to alterations in central fatigue mechanisms, muscle contraction mode during jump execution and changes in spinal cord excitability. These findings have important implications for power endurance sport performance and for neuromotor rehabilitation.

  20. Meta-analysis of transcutaneous electrical nerve stimulation for relief of spinal pain.

    Science.gov (United States)

    Resende, L; Merriwether, E; Rampazo, É P; Dailey, D; Embree, J; Deberg, J; Liebano, R E; Sluka, K A

    2018-04-01

    We conducted a systematic review and meta-analysis analysing the existing data on transcutaneous electrical nerve stimulation (TENS) or interferential current (IFC) for chronic low back pain (CLBP) and/or neck pain (CNP) taking into account intensity and timing of stimulation, examining pain, function and disability. Seven electronic databases were searched for TENS or IFC treatment in non-specific CLBP or CNP. Four reviewers independently selected randomized controlled trials (RCTs) of TENS or IFC intervention in adult individuals with non-specific CLBP or CNP. Primary outcomes were for self-reported pain intensity and back-specific disability. Two reviewers performed quality assessment, and two reviewers extracted data using a standardized form. Nine RCTs were selected (eight CLBP; one CNP), and seven studies with complete data sets were included for meta-analysis (655 participants). For CLBP, meta-analysis shows TENS/IFC intervention, independent of time of assessment, was significantly different from placebo/control (p TENS/IFC intervention was better than placebo/control, during therapy (p = 0.02), but not immediately after therapy (p = 0.08), or 1-3 months after therapy (p = 0.99). Analysis for adequate stimulation parameters was not significantly different, and there was no effect on disability. This systematic review provides inconclusive evidence of TENS benefits in low back pain patients because the quality of the studies was low, and adequate parameters and timing of assessment were not uniformly used or reported. Without additional high-quality clinical trials using sufficient sample sizes and adequate parameters and outcome assessments, the outcomes of this review are likely to remain unchanged. These data highlight the need for additional high-quality RCTs to examine the effects of TENS in CLBP. Trials should consider intensity of stimulation, timing of outcome assessment and assessment of pain, disability and function. © 2017 European Pain

  1. A controlled trial of transcutaneous electrical nerve stimulation (TENS) and exercise for chronic low back pain.

    Science.gov (United States)

    Deyo, R A; Walsh, N E; Martin, D C; Schoenfeld, L S; Ramamurthy, S

    1990-06-07

    A number of treatments are widely prescribed for chronic back pain, but few have been rigorously evaluated. We examined the effectiveness of transcutaneous electrical nerve stimulation (TENS), a program of stretching exercises, or a combination of both for low back pain. Patients with chronic low back pain (median duration, 4.1 years) were randomly assigned to receive daily treatment with TENS (n = 36), sham TENS (n = 36), TENS plus a program of exercises (n = 37), or sham TENS plus exercises (n = 36). After one month no clinically or statistically significant treatment effect of TENS was found on any of 11 indicators of outcome measuring pain, function, and back flexion; there was no interactive effect of TENS with exercise. Overall improvement in pain indicators was 47 percent with TENS and 42 percent with sham TENS (P not significant). The 95 percent confidence intervals for group differences excluded a major clinical benefit of TENS for most outcomes. By contrast, after one month patients in the exercise groups had significant improvement in self-rated pain scores, reduction in the frequency of pain, and greater levels of activity as compared with patients in the groups that did not exercise. The mean reported improvement in pain scores was 52 percent in the exercise groups and 37 percent in the nonexercise groups (P = 0.02). Two months after the active intervention, however, most patients had discontinued the exercises, and the initial improvements were gone. We conclude that for patients with chronic low back pain, treatment with TENS is no more effective than treatment with a placebo, and TENS adds no apparent benefit to that of exercise alone.

  2. Upper-airway flow limitation and transcutaneous carbon dioxide during sleep in normal pregnancy.

    Science.gov (United States)

    Rimpilä, Ville; Jernman, Riina; Lassila, Katariina; Uotila, Jukka; Huhtala, Heini; Mäenpää, Johanna; Polo, Olli

    2017-08-01

    Sleep during pregnancy involves a physiological challenge to provide sufficient gas exchange to the fetus. Enhanced ventilatory responses to hypercapnia and hypoxia may protect from deficient gas exchange, but sleep-disordered breathing (SDB) may predispose to adverse events. The aim of this study was to analyze sleep and breathing in healthy pregnant women compared to non-pregnant controls, with a focus on CO 2 changes and upper-airway flow limitation. Healthy women in the third trimester and healthy non-pregnant women with normal body mass index (BMI) were recruited for polysomnography. Conventional analysis of sleep and breathing was performed. Transcutaneous carbon dioxide (TcCO 2 ) was determined for each sleep stage. Flow-limitation was analyzed using the flattening index and TcCO 2 values were recorded for every inspiration. Eighteen pregnant women and 12 controls were studied. Pregnancy was associated with shorter sleep duration and more superficial sleep. Apnea-hypopnea index, arterial oxyhemoglobin desaturation, flow-limitation, snoring or periodic leg movements were similar in the two groups. Mean SaO 2 and minimum SaO 2 were lower and average heart rate was higher in the pregnant group. TcCO 2 levels did not differ between groups but variance of TcCO 2 was smaller in pregnant women during non-rapid eye movement (NREM). TcCO 2 profiles showed transient TcCO 2 peaks, which seem specific to pregnancy. Healthy pregnancy does not predispose to SDB. Enhanced ventilatory control manifests as narrowing threshold of TcCO 2 between wakefulness and sleep. Pregnant women have a tendency for rapid CO 2 increases during sleep which might have harmful consequences if not properly compensated. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Effects of different frequencies of transcutaneous electrical nerve stimulation on venous vascular reactivity

    International Nuclear Information System (INIS)

    Franco, O.S.; Paulitsch, F.S.; Pereira, A.P.C.; Teixeira, A.O.; Martins, C.N.; Silva, A.M.V.; Plentz, R.D.M.; Irigoyen, M.C.; Signori, L.U.

    2014-01-01

    Transcutaneous electrical nerve stimulation (TENS) is a type of therapy used primarily for analgesia, but also presents changes in the cardiovascular system responses; its effects are dependent upon application parameters. Alterations to the cardiovascular system suggest that TENS may modify venous vascular response. The objective of this study was to evaluate the effects of TENS at different frequencies (10 and 100 Hz) on venous vascular reactivity in healthy subjects. Twenty-nine healthy male volunteers were randomized into three groups: placebo (n=10), low-frequency TENS (10 Hz, n=9) and high-frequency TENS (100 Hz, n=10). TENS was applied for 30 min in the nervous plexus trajectory from the superior member (from cervical to dorsal region of the fist) at low (10 Hz/200 μs) and high frequency (100 Hz/200 μs) with its intensity adjusted below the motor threshold and intensified every 5 min, intending to avoid accommodation. Venous vascular reactivity in response to phenylephrine, acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent) was assessed by the dorsal hand vein technique. The phenylephrine effective dose to achieve 70% vasoconstriction was reduced 53% (P<0.01) using low-frequency TENS (10 Hz), while in high-frequency stimulation (100 Hz), a 47% increased dose was needed (P<0.01). The endothelium-dependent (acetylcholine) and independent (sodium nitroprusside) responses were not modified by TENS, which modifies venous responsiveness, and increases the low-frequency sensitivity of α1-adrenergic receptors and shows high-frequency opposite effects. These changes represent an important vascular effect caused by TENS with implications for hemodynamics, inflammation and analgesia

  4. Ameliorating effect of transcutaneous electroacupuncture on impaired gastric accommodation induced by cold meal in healthy subjects.

    Science.gov (United States)

    Huang, Zhihui; Zhang, Nina; Xu, Feng; Yin, Jieyun; Dai, Ning; Chen, Jiande D Z

    2016-03-01

    Impaired gastric accommodation is recognized as one of major pathophysiologies in functional dyspepsia and gastroparesis. Electroacupuncture has been shown to improve gastric accommodation in laboratory settings. It is, however, unknown whether it exerts similar ameliorating effect in humans and whether needleless transcutaneous electroacupuncture (TEA) is also effective in improving gastric accommodation. The aim was to investigate the effects of TEA on gastric accommodation, gastric slow waves, and dyspeptic related symptoms. Thirteen healthy volunteers were studied in four randomized sessions: control, cold nutrient liquid, cold nutrient liquid + sham-TEA, and cold nutrient liquid + TEA. The subjects were requested to drink Ensure until reaching maximum satiety. The electrogastrogram (EGG) and electrocardiogram (ECG) were recorded to assess the gastric and autonomic functions respectively. 1) Gastric accommodation was reduced with the cold drink in comparison with the warm drink (P = 0.023). TEA improved the impaired gastric accommodation from 539.2 ± 133.8 ml to 731.0 ± 185.7 ml (P = 0.005). 2) The percentage of normal gastric slow waves in six subjects was significantly decreased in the cold session (P = 0.002) and improved in the TEA session (P = 0.009 vs sham; P  0.05). TEA improves impaired gastric accommodation and slow waves induced by cold drink and the effect does not seem to be mediated via the vagal mechanisms. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  5. Effects of different frequencies of transcutaneous electrical nerve stimulation on venous vascular reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Franco, O.S.; Paulitsch, F.S.; Pereira, A.P.C.; Teixeira, A.O. [Universidade Federal do Rio Grande, Faculdade de Medicina, Programa de Pós-Graduação em Ciências da Saúde, Rio Grande, RS, Brasil, Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Medicina, Universidade Federal do Rio Grande, Rio Grande, RS (Brazil); Martins, C.N. [Universidade Federal do Rio Grande, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Fisiologia Animal Comparada, Rio Grande, RS, Brasil, Programa de Pós-Graduação em Fisiologia Animal Comparada, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rio Grande, RS (Brazil); Silva, A.M.V. [Universidade Federal de Santa Maria, Departamento de Fisioterapia e Reabilitação, Santa Maria, RS, Brasil, Departamento de Fisioterapia e Reabilitação, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Plentz, R.D.M. [Universidade Federal de Ciências da Saúde de Porto Alegre, Programa de Pós-Graduação em Ciências da Reabilitação, Programa de Pós-Graduação em Ciências da Saúde, Porto Alegre, RS, Brasil, Programa de Pós-Graduação em Ciências da Saúde, Programa de Pós-Graduação em Ciências da Reabilitação, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS (Brazil); Irigoyen, M.C. [Faculdade de Medicina, Universidade de São Paulo, Instituto do Coração, Unidade de Hipertensão, São Paulo, SP, Brasil, Unidade de Hipertensão, Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Signori, L.U. [Universidade Federal do Rio Grande, Faculdade de Medicina, Programa de Pós-Graduação em Ciências da Saúde, Rio Grande, RS, Brasil, Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Medicina, Universidade Federal do Rio Grande, Rio Grande, RS (Brazil); Universidade Federal do Rio Grande, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Fisiologia Animal Comparada, Rio Grande, RS, Brasil, Programa de Pós-Graduação em Fisiologia Animal Comparada, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rio Grande, RS (Brazil); Universidade Federal de Santa Maria, Departamento de Fisioterapia e Reabilitação, Santa Maria, RS, Brasil, Departamento de Fisioterapia e Reabilitação, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil)

    2014-04-04

    Transcutaneous electrical nerve stimulation (TENS) is a type of therapy used primarily for analgesia, but also presents changes in the cardiovascular system responses; its effects are dependent upon application parameters. Alterations to the cardiovascular system suggest that TENS may modify venous vascular response. The objective of this study was to evaluate the effects of TENS at different frequencies (10 and 100 Hz) on venous vascular reactivity in healthy subjects. Twenty-nine healthy male volunteers were randomized into three groups: placebo (n=10), low-frequency TENS (10 Hz, n=9) and high-frequency TENS (100 Hz, n=10). TENS was applied for 30 min in the nervous plexus trajectory from the superior member (from cervical to dorsal region of the fist) at low (10 Hz/200 μs) and high frequency (100 Hz/200 μs) with its intensity adjusted below the motor threshold and intensified every 5 min, intending to avoid accommodation. Venous vascular reactivity in response to phenylephrine, acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent) was assessed by the dorsal hand vein technique. The phenylephrine effective dose to achieve 70% vasoconstriction was reduced 53% (P<0.01) using low-frequency TENS (10 Hz), while in high-frequency stimulation (100 Hz), a 47% increased dose was needed (P<0.01). The endothelium-dependent (acetylcholine) and independent (sodium nitroprusside) responses were not modified by TENS, which modifies venous responsiveness, and increases the low-frequency sensitivity of α1-adrenergic receptors and shows high-frequency opposite effects. These changes represent an important vascular effect caused by TENS with implications for hemodynamics, inflammation and analgesia.

  6. Speaker and Observer Perceptions of Physical Tension during Stuttering.

    Science.gov (United States)

    Tichenor, Seth; Leslie, Paula; Shaiman, Susan; Yaruss, J Scott

    2017-01-01

    Speech-language pathologists routinely assess physical tension during evaluation of those who stutter. If speakers experience tension that is not visible to clinicians, then judgments of severity may be inaccurate. This study addressed this potential discrepancy by comparing judgments of tension by people who stutter and expert clinicians to determine if clinicians could accurately identify the speakers' experience of physical tension. Ten adults who stutter were audio-video recorded in two speaking samples. Two board-certified specialists in fluency evaluated the samples using the Stuttering Severity Instrument-4 and a checklist adapted for this study. Speakers rated their tension using the same forms, and then discussed their experiences in a qualitative interview so that themes related to physical tension could be identified. The degree of tension reported by speakers was higher than that observed by specialists. Tension in parts of the body that were less visible to the observer (chest, abdomen, throat) was reported more by speakers than by specialists. The thematic analysis revealed that speakers' experience of tension changes over time and that these changes may be related to speakers' acceptance of stuttering. The lack of agreement between speaker and specialist perceptions of tension suggests that using self-reports is a necessary component for supporting the accurate diagnosis of tension in stuttering. © 2018 S. Karger AG, Basel.

  7. Structural design significance of tension-tension fatigue data on composites

    Science.gov (United States)

    Grimes, G. C.

    1977-01-01

    Constant cycle tension-tension fatigue and related static tension data have been generated on six single composite material/orientation combinations and twenty-one hybrid composite material/orientation combinations. Anomalies are related to the temperature rise and stopped interval creep, whereas endurance limit stresses (runouts) are associated with static proportional limit values, when they occur, and internal damage. The significance of these room temperature-dry data on the design allowables and weight of aerodynamic structueres is discussed. Such structures are helicopter rotor blades and wing and horizontal stabilizer lower surfaces. Typical criteria for turning these data into preliminary allowables are shown, as are examples of such allowables developed from the data. These values are then compared to those that might be used if the structures were made of metal.

  8. Preliminary audiologic and peri-operative outcomes of the Sophono™ transcutaneous bone conduction device: A systematic review.

    Science.gov (United States)

    Bezdjian, Aren; Bruijnzeel, Hanneke; Daniel, Sam J; Grolman, Wilko; Thomeer, Hans G X M

    2017-10-01

    To delineate the auditory functional improvement and peri-operative outcomes of the Sophono™ transcutaneous bone conduction device. Eligible articles presenting patients implanted with the Sophono™ were identified through a comprehensive search of PubMed and Embase electronic databases. All relevant articles were reviewed to justify inclusion independently by 2 authors. Studies that successfully passed critical appraisal for directness of evidence and risk of bias were included. From a total of 125 articles, 8 studies encompassing 86 patients using 99 implants were selected. Most patients (79.1%) were children. Ear atresia (67.5%) was the most frequently reported indication for Sophono™ implantation. Overall pure tone average auditory improvement was 31.10 (±8.29) decibel. During a mean follow-up time of 12.48 months, 25 patients (29%) presented with post-operative complications from which 3 were deemed as serious implant-related adverse events (3.5%). The Sophono™ transcutaneous bone conduction device shows promising functional improvement, no intra-operative complications and minor post-operative skin related complications. If suitable, the device could be a proposed solution for the rehabilitation of hearing in children meeting eligibility criteria. A wearing schedule must be implemented in order to reduce magnet-related skin complications. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Efficacy of electroacupuncture compared with transcutaneous electric nerve stimulation for functional constipation: Study protocol for a randomized, controlled trial.

    Science.gov (United States)

    Zeng, Yuxiao; Zhang, Xuecheng; Zhou, Jing; Wang, Xinwei; Jiao, Ruimin; Liu, Zhishun

    2018-05-01

    To treat functional constipation, both electroacupuncture (EA) therapy and transcutaneous electric nerve stimulation (TENS) are safe and effective. However, no head-to-head comparison trial has been conducted. This trial compares the efficacy of electroacupuncture relative to transcutaneous electric nerve stimulation for functional constipation. Individuals with functional constipation will be randomly allocated to receive either EA or TENS (n = 51, each), 3 times per week for 8 weeks. The primary outcome is the percentage of participants with an average increase from baseline of 1 or more complete spontaneous bowel movements at week 8. The secondary outcome measures are the following: at the time of visits, changes in the number of complete spontaneous bowel movements, number of spontaneous bowel movements, stool character, difficulty in defecation, patients' assessment of quality of life regarding constipation (self-report questionnaire), and use of auxiliary defecation methods. The results of this trial should verify whether EA is more efficacious than TENS for relieving symptoms of functional constipation. The major limitation of the study is the lack of blinding of the participants and acupuncturist.

  10. Effects of transcutaneous electrical nerve stimulation (TENS) on cognition, behavior, and the rest-activity rhythm in children with attention deficit hyperactivity disorder, combined type

    NARCIS (Netherlands)

    Jonsdottir, S; Bouma, A; Sergeant, JA; Scherder, EJA; Bouma, J.M.

    2004-01-01

    Objective. The aim of this study was to examine the effects of transcutaneous electrical nerve stimulation (TENS) on cognition, behavior, and the rest-activity rhythm in children with attention deficit hyperactivity disorder, combined type (ADHD-CT). Methods. Twenty-two children diagnosed with

  11. Different mechanisms for the short-term effects of real versus sham transcutaneous electrical nerve stimulation (TENS) in patients with chronic pain: a pilot study.

    NARCIS (Netherlands)

    Oosterhof, J.; Wilder-Smith, O.H.G.; Oostendorp, R.A.B.; Crul, B.J.P.

    2012-01-01

    Transcutaneous electrical nerve stimulation (TENS) has existed since the early 1970s. However, randomized placebo controlled studies show inconclusive results in the treatment of chronic pain. These results could be explained by assuming that TENS elicits a placebo response. However, in animal

  12. Outcome of transcutaneous electrical nerve stimulation in chronic pain: short-term results of a double-blind, randomised, placebo-controlled trial.

    NARCIS (Netherlands)

    Oosterhof, J.; Boo, T.M. de; Oostendorp, R.A.B.; Wilder-Smith, O.H.G.; Crul, B.J.P.

    2006-01-01

    The aim of this study was to test the efficacy of shortterm transcutaneous electrical nerve stimulation (TENS) treatment in chronic pain with respect to pain intensity and patients' satisfaction with treatment results. We therefore performed a randomised controlled trial comparing TENS and sham

  13. Effects of transcutaneous electrical nerve stimulation on cognition, behavior, and rest-activity rhythm in children with Attention Deficit Hyperactivity Disorder, combined type

    NARCIS (Netherlands)

    Jonsdottir, S.; Bouma, A.; Sergeant, J.A.; Scherder, E.J.A.

    2004-01-01

    Objective. The aim of this study was to examine the effects of transcutaneous electrical nerve stimulation (TENS) on cognition, behavior, and the rest-activity rhythm in children with attention deficit hyperactivity disorder, combined type (ADHD-CT). Methods. Twenty-two children diagnosed with

  14. Cuerpo y subjetividad: materiales y tensiones

    OpenAIRE

    Cachorro, Gabriel

    2007-01-01

    En este artículo se efectúa un abordaje del tema cuerpo y subjetividad a través de un ejercicio exploratorio de sus materiales y tensiones. Las preguntas posibles de formular son: ¿Qué discusiones tenemos por debajo de la subjetividad corporal?, ¿cuáles son las raíces históricas de este tema?, ¿qué problemáticas lo atraviesan? La enunciación de estos interrogantes nos ayuda a establecer la posición de investigador y a explicitar los argumentos teóricos. Se desprende de esta propuest...

  15. Temporomandibular disorders and tension-type headache.

    Science.gov (United States)

    Mongini, Franco

    2007-12-01

    Pathologies currently defined as temporomandibular disorders may be different in nature. Temporomandibular joint (TMJ) disorders and craniofacial and cervical myogenous pain (MP) are distinct pathologies but may be superimposed and share some etiologic factors. Tension-type headache (TTH) may often be associated with craniofacial and cervical pain, and the same pharmacologic and nonpharmacologic treatment may be efficacious for both. Psychiatric comorbidity (depression and/or anxiety disorder) is less frequent in sheer TMJ disorders, compared with MP and TTH. A screening for the presence of an underlying psychiatric disorder should be part of the clinical evaluation in patients suffering from headache and facial pain.

  16. Small-Bolt Torque-Tension Tester

    Science.gov (United States)

    Posey, Alan J.

    2009-01-01

    The device described here measures the torque-tension relationship for fasteners as small as #0. The small-bolt tester consists of a plate of high-strength steel into which three miniature load cells are recessed. The depth of the recess is sized so that the three load cells can be shimmed, the optimum height depending upon the test hardware. The three miniature load cells are arranged in an equilateral triangular configuration with the test bolt aligned with the centroid of the three. This is a kinematic arrangement.

  17. Superficial tension: experimental model with simple materials

    Directory of Open Access Journals (Sweden)

    Tintori Ferreira, María Alejandra

    2012-09-01

    Full Text Available In this work appears a didactic offer based on an experimental activity using materials of very low cost, orientated to achieving that the student understand and interpret the phenomenon of superficial tension together with the importance of the modeling in sciences. It has as principal aim of education bring the student over to the mechanics of the static fluids and the intermolecular forces, combining scientific contents with questions near to the student what provides an additional motivation to the reflection of the scientific investigation.

  18. Effective tension and fluctuations in active membranes

    OpenAIRE

    Loubet, Bastien; Seifert, Udo; Lomholt, Michael Andersen

    2011-01-01

    We calculate the fluctuation spectrum of the shape of a lipid vesicle or cell exposed to a nonthermal source of noise. In particular we take into account constraints on the membrane area and the volume of fluid that it encapsulates when obtaining expressions for the dependency of the membrane tension on the noise. We then investigate three possible origins of the non-thermal noise taken from the literature: A direct force, which models an external medium pushing on the membrane. A curvature f...

  19. A polarized view on DNA under tension

    Science.gov (United States)

    van Mameren, Joost; Vermeulen, Karen; Wuite, Gijs J. L.; Peterman, Erwin J. G.

    2018-03-01

    In the past decades, sensitive fluorescence microscopy techniques have contributed significantly to our understanding of the dynamics of DNA. The specific labeling of DNA using intercalating dyes has allowed for quantitative measurement of the thermal fluctuations the polymers undergo. On the other hand, recent advances in single-molecule manipulation techniques have unraveled the mechanical and elastic properties of this intricate polymer. Here, we have combined these two approaches to study the conformational dynamics of DNA under a wide range of tensions. Using polarized fluorescence microscopy in conjunction with optical-tweezers-based manipulation of YOYO-intercalated DNA, we controllably align the YOYO dyes using DNA tension, enabling us to disentangle the rapid dynamics of the dyes from that of the DNA itself. With unprecedented control of the DNA alignment, we resolve an inconsistency in reports about the tilted orientation of intercalated dyes. We find that intercalated dyes are on average oriented perpendicular to the long axis of the DNA, yet undergo fast dynamics on the time scale of absorption and fluorescence emission. In the overstretching transition of double-stranded DNA, we do not observe changes in orientation or orientational dynamics of the dyes. Only beyond the overstretching transition, a considerable depolarization is observed, presumably caused by an average tilting of the DNA base pairs. Our combined approach thus contributes to the elucidation of unique features of the molecular dynamics of DNA.

  20. Shape accuracy optimization for cable-rib tension deployable antenna structure with tensioned cables

    Science.gov (United States)

    Liu, Ruiwei; Guo, Hongwei; Liu, Rongqiang; Wang, Hongxiang; Tang, Dewei; Song, Xiaoke

    2017-11-01

    Shape accuracy is of substantial importance in deployable structures as the demand for large-scale deployable structures in various fields, especially in aerospace engineering, increases. The main purpose of this paper is to present a shape accuracy optimization method to find the optimal pretensions for the desired shape of cable-rib tension deployable antenna structure with tensioned cables. First, an analysis model of the deployable structure is established by using finite element method. In this model, geometrical nonlinearity is considered for the cable element and beam element. Flexible deformations of the deployable structure under the action of cable network and tensioned cables are subsequently analyzed separately. Moreover, the influence of pretension of tensioned cables on natural frequencies is studied. Based on the results, a genetic algorithm is used to find a set of reasonable pretension and thus minimize structural deformation under the first natural frequency constraint. Finally, numerical simulations are presented to analyze the deployable structure under two kinds of constraints. Results show that the shape accuracy and natural frequencies of deployable structure can be effectively improved by pretension optimization.

  1. Transcutaneous spinal direct current stimulation of the lumbar and sacral spinal cord: a modelling study

    Science.gov (United States)

    Fernandes, Sofia R.; Salvador, Ricardo; Wenger, Cornelia; de Carvalho, Mamede; Miranda, Pedro C.

    2018-06-01

    Objective. Our aim was to perform a computational study of the electric field (E-field) generated by transcutaneous spinal direct current stimulation (tsDCS) applied over the thoracic, lumbar and sacral spinal cord, in order to assess possible neuromodulatory effects on spinal cord circuitry related with lower limb functions. Approach. A realistic volume conductor model of the human body consisting of 14 tissues was obtained from available databases. Rubber pad electrodes with a metallic connector and a conductive gel layer were modelled. The finite element (FE) method was used to calculate the E-field when a current of 2.5 mA was passed between two electrodes. The main characteristics of the E-field distributions in the spinal grey matter (spinal-GM) and spinal white matter (spinal-WM) were compared for seven montages, with the anode placed either over T10, T8 or L2 spinous processes (s.p.), and the cathode placed over right deltoid (rD), umbilicus (U) and right iliac crest (rIC) areas or T8 s.p. Anisotropic conductivity of spinal-WM and of a group of dorsal muscles near the vertebral column was considered. Main results. The average E-field magnitude was predicted to be above 0.15 V m-1 in spinal cord regions located between the electrodes. L2-T8 and T8-rIC montages resulted in the highest E-field magnitudes in lumbar and sacral spinal segments (>0.30 V m-1). E-field longitudinal component is 3 to 6 times higher than the ventral-dorsal and right-left components in both the spinal-GM and WM. Anatomical features such as CSF narrowing due to vertebrae bony edges or disks intrusions in the spinal canal correlate with local maxima positions. Significance. Computational modelling studies can provide detailed information regarding the electric field in the spinal cord during tsDCS. They are important to guide the design of clinical tsDCS protocols that optimize stimulation of application-specific spinal targets.

  2. Intra-abdominal pressure alterations after large pancreatic pseudocyst transcutaneous drainage

    Directory of Open Access Journals (Sweden)

    Papavramidis Theodossis S

    2009-06-01

    Full Text Available Abstract Background Acute pancreatitis leads to abdominal hypertension and compartment syndrome. Weeks after the episodes pancreatic fluids sometimes organize to pseudocysts, fluid collections by or in the gland. Aims of the present study were to evaluate the intra-abdominal pressure (IAP induced by large pancreatic pseudocysts and to examine the effect of their transcutaneous drainage on IAP. Methods Twenty seven patients with a pancreatic pseudocyst were included. Nine patients with pseudocysts greater than 1l (group A had CT drainage and eighteen (volume less than 1l were the control group. The measurements of group A were taken 6 hours before and every morning after the drainage, while for group B, two measurements were performed, one at the day of the initial CT and one 7 days after. Abdominal compliance (Cabd was calculated. Data were analyzed using student's t-test. Results Baseline IAP for group A was 9.3 mmHg (S.D. 1.7 mmHg, while the first post-drainage day (PDD IAP was 5.1 mmHg (S.D. 0.7 mmHg. The second PDD IAP was 5.6 mmHg (S.D. 0.8 mmHg, the third 6.4 mmH (S.D. 1.2 mmHgg, the fourth 6.9 mmHg (S.D. 1.6 mmHg, the fifth 7.9 mmHg (S.D. 1.5 mmHg, the sixth 8.2 mmHg (S.D. 1.4 mmHg, and the seventh 8.2 mmHg (S.D. 1.5 mmHg. Group B had baseline IAP 8.0 mmHg (S.D. 1.2 mmHg and final 8.2 mmHg (S.D. 1.4 mmHg. Cabd after drainage was 185.6 ml/mmHg (SD 47.5 ml/mmHg. IAP values were reduced between the baseline and all the post-drainage measurements in group A. IAPs seem to stabilize after the 5th post-drainage day. Baseline IAP was higher in group A than in group B, while the two values, at day 7, were equivalent. Conclusion The drainage of large pancreatic pseudocyst reduces IAP. Moreover, the IAP seems to rise shortly after the drainage again, but in a way that it remains inferior to the initial value. More chronic changes to the IAP are related to abdominal cavity's properties and have to be further studied.

  3. Transcutaneous electrical nerve stimulation (TENS) for phantom pain and stump pain following amputation in adults.

    Science.gov (United States)

    Johnson, Mark I; Mulvey, Matthew R; Bagnall, Anne-Marie

    2015-08-18

    This is the first update of a Cochrane review published in Issue 5, 2010 on transcutaneous electrical nerve stimulation (TENS) for phantom pain and stump pain following amputation in adults. Pain may present in a body part that has been amputated (phantom pain) or at the site of amputation (stump pain), or both. Phantom pain and stump pain are complex and multidimensional and the underlying pathophysiology remains unclear. The condition remains a severe burden for those who are affected by it. The mainstay treatments are predominately pharmacological, with increasing acknowledgement of the need for non-drug interventions. TENS has been recommended as a treatment option but there has been no systematic review of available evidence. Hence, the effectiveness of TENS for phantom pain and stump pain is currently unknown. To assess the analgesic effectiveness of TENS for the treatment of phantom pain and stump pain following amputation in adults. For the original version of the review we searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, AMED, CINAHL, PEDRO and SPORTDiscus (February 2010). For this update, we searched the same databases for relevant randomised controlled trials (RCTs) from 2010 to 25 March 2015. We only included RCTs investigating the use of TENS for the management of phantom pain and stump pain following an amputation in adults. Two review authors independently assessed trial quality and extracted data. We planned that where available and appropriate, data from outcome measures were to be pooled and presented as an overall estimate of the effectiveness of TENS. In the original review there were no RCTs that examined the effectiveness of TENS for the treatment of phantom pain and stump pain in adults. For this update, we did not identify any additional RCTs for inclusion. There were no RCTs to judge the effectiveness of TENS for the management of phantom pain and stump pain. The published literature on TENS

  4. Inhibition of Parkinsonian tremor with cutaneous afferent evoked by transcutaneous electrical nerve stimulation.

    Science.gov (United States)

    Hao, Man-Zhao; Xu, Shao-Qin; Hu, Zi-Xiang; Xu, Fu-Liang; Niu, Chuan-Xin M; Xiao, Qin; Lan, Ning

    2017-07-14

    Recent study suggests that tremor signals are transmitted by way of multi-synaptic corticospinal pathway. Neurophysiological studies have also demonstrated that cutaneous afferents exert potent inhibition to descending motor commands by way of spinal interneurons. We hypothesize in this study that cutaneous afferents could also affect the transmission of tremor signals, thus, inhibit tremor in patients with PD. We tested this hypothesis by activating cutaneous afferents in the dorsal hand skin innervated by superficial radial nerve using transcutaneous electrical nerve stimulation (TENS). Eight patients with PD having tremor dominant symptom were recruited to participate in this study using a consistent experimental protocol for tremor inhibition. Resting tremor and electromyogram (EMG) of muscles in the upper extremity of these subjects with PD were recorded, while surface stimulation was applied to the dorsal skin of the hand. Fifteen seconds of data were recorded for 5 s prior to, during and post stimulation. Power spectrum densities (PSDs) of tremor and EMG signals were computed for each data segment. The peak values of PSDs in three data segments were compared to detect evidence of tremor inhibition. At stimulation intensity from 1.5 to 1.75 times of radiating sensation threshold, apparent suppressions of tremor at wrist, forearm and upper arm and in the EMGs were observed immediately at the onset of stimulation. After termination of stimulation, tremor and rhythmic EMG bursts reemerged gradually. Statistical analysis of peak spectral amplitudes showed a significant difference in joint tremors and EMGs during and prior to stimulation in all 8 subjects with PD. The average percentage of suppression was 61.56% in tremor across all joints of all subjects, and 47.97% in EMG of all muscles. The suppression appeared to occur mainly in distal joints and muscles. There was a slight, but inconsistent effect on tremor frequency in the 8 patients with PD tested. Our

  5. Validation of a transcutaneous bilirubin meter in Mongolian neonates: comparison with total serum bilirubin.

    Science.gov (United States)

    Akahira-Azuma, Moe; Yonemoto, Naohiro; Ganzorig, Battsengel; Mori, Rintaro; Hosokawa, Shinichi; Matsushita, Takeji; Bavuusuren, Bayasgalantai; Shonkhuuz, Enkhtur

    2013-09-27

    Neonatal hyperbilirubinemia, especially kernicterus, can be prevented by screening for neonatal jaundice. The transcutaneous bilirubin (TcB) meter is a non-invasive medical device for screening neonates. The study aimed to investigate the validity of a TcB meter in a resource-limited setting such as Mongolia. Term and late preterm neonates from the National Center for Maternal and Child Health of Ulaanbaatar in Mongolia who met the inclusion criteria (gestational age ≥35 weeks, birth weight ≥2000 g, postnatal age ≤ 1 month) were enrolled in the study. We used a TcB meter, JM-103 to screen for neonatal jaundice. TcB measurements at the infant's forehead and midsternum were performed within 3 h of obtaining samples for total serum bilirubin (TSB) measurement. We analyzed the correlation between TcB measurements and TSB measurements to validate the meter. A total of 47 term and six late preterm neonates were included in the study. TcB measured by the meter at both the forehead and the midsternum showed a strong correlation with TSB measured in the laboratory. The correlation equations were TSB = 1.409+0.8655 × TcB (R2=0.78871) at the forehead, and TSB = 0.7555+0.8974 × TcB (R2=0.78488) at the midsternum. Bland-Altman plots and the Bradley-Blackwood test showed no significant differences between the two methods at all measured ranges of bilirubin. The mean areas under the curves of TcB at the forehead and midsternum at three TSB levels (>10 mg/dL, >13 mg/dL, >15 mg/dL) of TcB were greater than 0.9, and all had high sensitivity and specificity. This study established the validity of the JM-103 meter as a screening tool for neonatal jaundice in term and late preterm infants in Mongolia. Future studies are needed, including the establishment of a TcB hour-specific nomogram, for more effective clinical practice to prevent severe hyperbilirubinemia.

  6. Transcutaneous electrical nerve stimulation (TENS) for chronic low-back pain.

    Science.gov (United States)

    Khadilkar, A; Milne, S; Brosseau, L; Robinson, V; Saginur, M; Shea, B; Tugwell, P; Wells, G

    2005-07-20

    Chronic low-back pain (LBP) affects a significant proportion of the population. Transcutaneous electrical nerve stimulation (TENS) was introduced more than 30 years ago as an adjunct to the pharmacological management of pain. However, despite its widespread use, the usefulness of TENS in chronic LBP is still controversial. The aim of this systematic review was to determine the effectiveness of TENS in the management of chronic LBP. We searched the Cochrane Central Register of Controlled Trials (Issue 2, 2005), MEDLINE, EMBASE and PEDro up to April 1, 2005. Only randomized controlled clinical trials (RCTs) evaluating the effect of TENS on chronic LBP were included. Abstracts were excluded unless further data could be obtained from the authors. Two reviewers independently selected trials and extracted data using predetermined forms. Heterogeneity was tested with Cochrane's Q test. A fixed effect model was used throughout for calculating continuous variables, except where heterogeneity existed, in which case, a random effects model was used. Results are presented as weighted mean differences (WMD) with 95% confidence intervals (95% CI), where the difference between the treated and control groups was weighted by the inverse of the variance. Standardized mean differences (SMD) were calculated by dividing the difference between the treated and control by the baseline variance. SMD were used when different scales were used to measure the same concept. Dichotomous outcomes were analyzed with odds ratios. The only two RCTs (175 patients) meeting eligibility criteria differed in study design, methodological quality, inclusion and exclusion criteria, type and method of TENS application, treatment schedule, co-interventions and final outcomes. In one RCT, TENS produced significantly greater pain relief than the placebo control. However, in the other RCT, no statistically significant differences between treatment and control groups were shown for multiple outcome measures. Pre

  7. Transcutaneous electrical nerve stimulation (TENS) versus placebo for chronic low-back pain.

    Science.gov (United States)

    Khadilkar, Amole; Odebiyi, Daniel Oluwafemi; Brosseau, Lucie; Wells, George A

    2008-10-08

    Transcutaneous electrical nerve stimulation (TENS) was introduced more than 30 years ago as a therapeutic adjunct to the pharmacological management of pain. However, despite widespread use, its effectiveness in chronic low-back pain (LBP) is still controversial. To determine whether TENS is more effective than placebo for the management of chronic LBP. The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, PEDro and CINAHL were searched up to July 19, 2007. Only randomized controlled clinical trials (RCTs) comparing TENS to placebo in patients with chronic LBP were included. Two review authors independently selected the trials, assessed their methodological quality and extracted relevant data. If quantitative meta-analysis was not possible, a qualitative synthesis was performed, taking into consideration 5 levels of evidence as recommended by the Cochrane Collaboration Back Review Group. Four high-quality RCTs (585 patients) met the selection criteria. Clinical heterogeneity prevented the use of meta-analysis. Therefore, a qualitative synthesis was completed. There was conflicting evidence about whether TENS was beneficial in reducing back pain intensity and consistent evidence in two trials (410 patients) that it did not improve back-specific functional status. There was moderate evidence that work status and the use of medical services did not change with treatment. Conflicting results were obtained from two studies regarding generic health status, with one study showing no improvement on the modified Sickness Impact Profile and another study showing significant improvements on several, but not all subsections of the SF-36 questionnaire. Multiple physical outcome measures lacked statistically significant improvement relative to placebo. In general, patients treated with acupuncture-like TENS responded similarly to those treated with conventional TENS. However, in two of the trials, an inadequate stimulation intensity was used for acupuncture

  8. Transcutaneous electrical nerve stimulation for the treatment of chronic low back pain: a systematic review.

    Science.gov (United States)

    Khadilkar, Amole; Milne, Sarah; Brosseau, Lucie; Wells, George; Tugwell, Peter; Robinson, Vivian; Shea, Beverley; Saginur, Michael

    2005-12-01

    Systematic review. To determine the effectiveness of transcutaneous electrical nerve stimulation (TENS) in the management of chronic LBP. Chronic low back pain (LBP) affects a significant proportion of the population. TENS was introduced more than 30 years ago as an adjunct to pharmacologic pain management. However, despite its widespread use, the usefulness of TENS in chronic LBP is still controversial. We searched MEDLINE, EMBASE, PEDro, and the Cochrane Central Register of Controlled Trials (Issue 2, 2005), up to April 1, 2005. Only randomized controlled clinical trials (RCTs) evaluating the effect of TENS on chronic LBP were included. Two reviewers independently selected trials and extracted data using predetermined forms. Heterogeneity was tested with Cochrane's Q test. A fixed effect model was used throughout for calculating continuous variables, except where heterogeneity existed, in which case a random effects model was used. Results are presented as weighted mean differences with 95% confidence intervals (95% CI), where the difference between the treated and control groups was weighted by the inverse of the variance. Standardized mean differences were calculated by dividing the difference between the treated and control by the baseline variance. Standardized mean differences were used when different scales were used to measure the same concept. Dichotomous outcomes were analyzed with odds ratios. Two RCTs (175 patients) were included. They differed with respect to study design, methodologic quality, inclusion and exclusion criteria, characteristics of TENS application, treatment schedule, cointerventions, and measured outcomes. In one RCT, TENS produced significantly greater pain relief than the placebo control. However, in the other RCT, no statistically significant differences between treatment and control groups were shown for multiple outcome measures. Preplanned subgroup analyses, intended to examine the impact of different stimulation parameters

  9. The tension of framed membranes from computer simulations

    DEFF Research Database (Denmark)

    Hamkens, Daniel; Jeppesen, Claus; Ipsen, John H.

    2018-01-01

    the membranes display power-law characteristics for the equation of state, while higher tension levels includes both an extended linear (elastic) as well as a highly non-linear stretching regime. For semi-flexible membranes a transition from extended to buckled conformations takes place at negative frame......Abstract.: We have analyzed the behavior of a randomly triangulated, self-avoiding surface model of a flexible, fluid membrane subject to a circular boundary by Wang-Landau Monte Carlo computer simulation techniques. The dependence of the canonical free energy and frame tension on the frame area...... is obtained for flexible membranes. It is shown that for low bending rigidities the framed membrane is only stable above a threshold tension, suggesting a discontinuous transition from the collapsed (branched polymer) state to a finite tension extended state. In a tension range above this threshold tension...

  10. Airway injury during emergency transcutaneous airway access: a comparison at cricothyroid and tracheal sites.

    LENUS (Irish Health Repository)

    Salah, Nazar

    2009-12-01

    Oxygenation via the cricothyroid membrane (CTM) may be required in emergencies, but inadvertent tracheal cannulation may occur. In this study, we compared airway injury between the tracheal and CTM sites using different techniques for airway access.

  11. No oxygen delivery limitation in hepatic encephalopathy

    DEFF Research Database (Denmark)

    Gjedde, Albert; Keiding, Susanne; Vilstrup, Hendrik

    2010-01-01

    to choose between cause and effect in three groups of volunteers, including healthy control subjects (HC), patients with cirrhosis of the liver without hepatic encephalopathy (CL), and patients with cirrhosis with acute hepatic encephalopathy. Compared to HC subjects, blood flow and energy metabolism had......Hepatic encephalopathy is a condition of reduced brain functioning in which both blood flow and brain energy metabolism declined. It is not known whether blood flow or metabolism is the primary limiting factor of brain function in this condition. We used calculations of mitochondrial oxygen tension...

  12. Surface tension of liquid Al-Cu binary alloys.

    OpenAIRE

    Schmitz, Julianna; Brillo, Jürgen; Egry, Ivan; Schmid-Fetzer, Rainer

    2009-01-01

    Surface tension data of liquid Al–Cu binary alloys have been measured contactlessly using the technique of electromagnetic levitation. A digital CMOS-camera (400 fps) recorded image sequences of the oscillating liquid sample and surface tensions were determined from analysis of the frequency spectra. Measurements were performed for samples covering the entire range of composition and precise data were obtained in a broad temperature range. It was found that the surface tensions can ...

  13. Oxygen transfer rate during the production of alginate by Azotobacter vinelandii under oxygen-limited and non oxygen-limited conditions

    Directory of Open Access Journals (Sweden)

    Peña Carlos F

    2011-02-01

    Full Text Available Abstract Background The oxygen transfer rate (OTR and dissolved oxygen tension (DOT play an important role in determining alginate production and its composition; however, no systematic study has been reported about the independent influence of the OTR and DOT. In this paper, we report a study about alginate production and the evolution of the molecular mass of the polymer produced by a wild-type A. vinelandii strain ATCC 9046, in terms of the maximum oxygen transfer rate (OTRmax in cultures where the dissolved oxygen tension (DOT was kept constant. Results The results revealed that in the two dissolved oxygen conditions evaluated, strictly controlled by gas blending at 0.5 and 5% DOT, an increase in the agitation rate (from 300 to 700 rpm caused a significant increase in the OTRmax (from 17 to 100 mmol L-1 h-1 for DOT of 5% and from 6 to 70 mmol L-1 h-1 for DOT of 0.5%. This increase in the OTRmax improved alginate production, as well as the specific alginate production rate (SAPR, reaching a maximal alginate concentration of 3.1 g L-1 and a SAPR of 0.031 g alg g biom-1 h-1 in the cultures at OTRmax of 100 mmol L-1 h-1. In contrast, the mean molecular mass (MMM of the alginate isolated from cultures developed under non-oxygen limited conditions increased by decreasing the OTRmax, reaching a maximal of 550 kDa at an OTRmax of 17 mmol L-1 h-1 . However, in the cultures developed under oxygen limitation (0.5% DOT, the MMM of the polymer was practically the same (around 200 kDa at 300 and 700 rpm, and this remained constant throughout the cultivation. Conclusions Overall, our results showed that under oxygen-limited and non oxygen-limited conditions, alginate production and its molecular mass are linked to the OTRmax, independently of the DOT of the culture.

  14. Bending Under Tension Test with Direct Friction Measurement

    DEFF Research Database (Denmark)

    Andreasen, Jan Lasson; Olsson, David Dam; Chodnikiewicz, K.

    2006-01-01

    A special Bending-Under-Tension (BUT) transducer has been developed in which friction around the tool radius can be directly measured when drawing a plane sheet strip around a cylindrical tool-pin under constant back tension. The front tension, back tension and torque on the tool-pin are all...... measured directly, thus enabling accurate measurement of friction and direct determination of lubricant film breakdown for varying normal pressure, sliding speed, tool radius and tool preheat temperature. The transducer is applied in an experimental investigation focusing on limits of lubrication...

  15. The law of corresponding states and surface tension of metals

    International Nuclear Information System (INIS)

    Digilov, R.

    2001-01-01

    Full Text: Surface tension of liquid metals is one of fundamental and most important quantities in theory and practice of material processing and its temperature dependence leads to the well-known Marangoni convection. Although currently methods are sufficiently precise to measure the surface tension, there are uncertainties in experimental data and its temperature dependence mainly due to impurity, which even a trace of it strongly affects the results of measurements. The theoretical treatment from the first principles is unwieldy and not always permits one to calculate the surface tension with certainty. Another active research field deals with empirical correlation between the surface tension and bulk thermodynamic properties, which we interpret as a simple consequence of the law of corresponding states. In order to relate the surface tension and to bulk properties of liquid metals the reduced formula is derived by scaling with the melting point T m (0) at p = 0 and atomic volume Ω 0 2/3 at T = 0 K as macroscopic parameters for scaling ε and a characterizing the interatomic potential in metals. The reduced surface tension and the reduced surface entropy obtained in high temperature limit are discussed and compared with the experiment. The reduced temperature coefficient of the surface tension found is a universal constant for the metals of the same structure. It is shown that pressure dependence of the surface tension, so called baric coefficient of the surface tension, can be described by pressure dependence of scaling parameters T m (p) and Ω 0 (p). (author)

  16. Strain Capacity of Reinforced Concrete Members Subjected to Uniaxial Tension

    DEFF Research Database (Denmark)

    Hagsten, Lars German; Rasmussen, Annette Beedholm; Fisker, Jakob

    2017-01-01

    The aim of this paper is to set up a method to determine the strain capacity of tension bars of reinforced concrete (RC) subjected to pure tension. Due to the interaction between reinforcement and concrete and due to the presence of cracks, the stresses in both reinforcement and concrete...... are varying along the length of the tension bar. The strain capacity of the tension bar is seen as the average strain in the reinforcement at the load level corresponding to the ultimate stress capacity of the reinforcement at the cracks. The result of the approach is in overall good agreement when comparing...

  17. An automatic tension measurement system of MWPC wires

    International Nuclear Information System (INIS)

    D'Antone, I.; Lolli, M.; Torromeo, G.

    1992-01-01

    An electronic system is presented for automatic mechanical tension measurement to test wire chambers. The developed system works in the tension range from 50 g to 300 g; this large working range is obtained by using a microcontroller that performs a digital control on the bridge of an oscillator containing the wire of which the tension has to be measured. The microcontroller automatically brings the system towards the oscillation condition and subsequently, measuring the frequency, it evaluates, displays and sends to a host computer the value of the mechanical tension of the wires. The system is precise and allows fast measurements. A description of the hardware and software design is given. (orig.)

  18. Breath ethane as a marker of reactive oxygen species during manipulation of diet and oxygen tension in rats.

    Science.gov (United States)

    Risby, T H; Jiang, L; Stoll, S; Ingram, D; Spangler, E; Heim, J; Cutler, R; Roth, G S; Rifkind, J M

    1999-02-01

    Breath ethane, O2 consumption, and CO2 production were analyzed in 24-mo-old female Fischer 344 rats that had been fed continuously ad libitum (AL) or restricted 30% of AL level (DR) diets since 6 wk of age. Rats were placed in a glass chamber that was first flushed with air, then with a gas mixture containing 12% O2. After equilibration, a sample of the outflow was collected in gas sampling bags for subsequent analyses of ethane and CO2. The O2 and CO2 levels were also directly monitored in the outflow of the chamber. O2 consumption and CO2 production increased for DR rats. Hypoxia decreased O2 consumption and CO2 production for the AL-fed and DR rats. These changes reflect changes in metabolic rate due to diet and PO2. A significant decrease in ethane generation was found in DR rats compared with AL-fed rats. Under normoxic conditions, breath ethane decreased from 2.20 to 1.61 pmol ethane/ml CO2. During hypoxia the levels of ethane generation increased, resulting in a DR-associated decrease in ethane from 2.60 to 1.90 pmol ethane/ml CO2. These results support the hypothesis that DR reduces the level of oxidative stress.

  19. Fixed-site high-frequency transcutaneous electrical nerve stimulation for treatment of chronic low back and lower extremity pain

    Science.gov (United States)

    Gozani, Shai N

    2016-01-01

    Objective The objective of this study was to determine if fixed-site high-frequency transcutaneous electrical nerve stimulation (FS-TENS) is effective in treating chronic low back and lower extremity pain. Background Transcutaneous electrical nerve stimulation is widely used for treatment of chronic pain. General-purpose transcutaneous electrical nerve stimulation devices are designed for stimulation anywhere on the body and often cannot be used while the user is active or sleeping. FS-TENS devices are designed for placement at a pre-determined location, which enables development of a wearable device for use over extended time periods. Methods Study participants with chronic low back and/or lower extremity pain self-administered an FS-TENS device for 60 days. Baseline, 30-, and 60-day follow-up data were obtained through an online questionnaire. The primary outcome measure was the patient global impression of change. Pain intensity and interference were assessed using the Brief Pain Inventory. Changes in use of concomitant pain medications were evaluated with a single-item global self-rating. Results One hundred and thirty participants were enrolled, with 88 completing the 60-day follow-up questionnaire. Most participants (73.9%) were 50 years of age or older. At baseline, low back pain was identified by 85.3%, lower extremity pain by 71.6%, and upper extremity pain by 62.5%. Participants reported widespread pain, at baseline, with a mean of 3.4 (standard deviation 1.1) pain sites. At the 60-day follow-up, 80.7% of participants reported that their chronic pain had improved and they were classified as responders. Baseline characteristics did not differentiate non-responders from responders. There were numerical trends toward reduced pain interference with walking ability and sleep, and greater pain relief in responders. There was a large difference in use of concomitant pain medications, with 80.3% of responders reporting a reduction compared to 11.8% of non

  20. Fixed-site high-frequency transcutaneous electrical nerve stimulation for treatment of chronic low back and lower extremity pain.

    Science.gov (United States)

    Gozani, Shai N

    2016-01-01

    The objective of this study was to determine if fixed-site high-frequency transcutaneous electrical nerve stimulation (FS-TENS) is effective in treating chronic low back and lower extremity pain. Transcutaneous electrical nerve stimulation is widely used for treatment of chronic pain. General-purpose transcutaneous electrical nerve stimulation devices are designed for stimulation anywhere on the body and often cannot be used while the user is active or sleeping. FS-TENS devices are designed for placement at a pre-determined location, which enables development of a wearable device for use over extended time periods. Study participants with chronic low back and/or lower extremity pain self-administered an FS-TENS device for 60 days. Baseline, 30-, and 60-day follow-up data were obtained through an online questionnaire. The primary outcome measure was the patient global impression of change. Pain intensity and interference were assessed using the Brief Pain Inventory. Changes in use of concomitant pain medications were evaluated with a single-item global self-rating. One hundred and thirty participants were enrolled, with 88 completing the 60-day follow-up questionnaire. Most participants (73.9%) were 50 years of age or older. At baseline, low back pain was identified by 85.3%, lower extremity pain by 71.6%, and upper extremity pain by 62.5%. Participants reported widespread pain, at baseline, with a mean of 3.4 (standard deviation 1.1) pain sites. At the 60-day follow-up, 80.7% of participants reported that their chronic pain had improved and they were classified as responders. Baseline characteristics did not differentiate non-responders from responders. There were numerical trends toward reduced pain interference with walking ability and sleep, and greater pain relief in responders. There was a large difference in use of concomitant pain medications, with 80.3% of responders reporting a reduction compared to 11.8% of non-responders. FS-TENS is a safe and effective