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Sample records for temperature hyperthermia referring

  1. Genetics Home Reference: malignant hyperthermia

    Science.gov (United States)

    ... 1722-30. Review. Citation on PubMed Litman RS, Rosenberg H. Malignant hyperthermia: update on susceptibility testing. JAMA. ... 27(10):977-89. Review. Citation on PubMed Rosenberg H, Davis M, James D, Pollock N, Stowell ...

  2. Long duration mild temperature hyperthermia and brachytherapy.

    Science.gov (United States)

    Armour, E P; Raaphorst, G P

    2004-03-01

    Combining long duration mild temperature hyperthermia (LDMH) and low dose-rate (LDR) brachytherapy to enhance therapeutic killing of cancer cells was proposed many years ago. The cellular and tumour research that supports this hypothesis is presented in this review. Research describing LDMH interaction with pulsed brachytherapy and high dose-rate brachytherapy using clinically relevant parameters are compared with LDMH/LDR brachytherapy. The mechanism by which LDMH sensitizes LDR has been established as the inhibition of sublethal damage repair. The molecular mechanisms have been shown to involve DNA repair enzymes, but the exact nature of these processes is still under investigation. The relative differences between LDMH interactions with human and rodent cells are presented to help in the understanding of possible roles of LDMH in clinical application. The role of LDMH in modifying tumour blood flow and its possible role in LDR sensitization of tumours is also presented. The positive aspects of LDMH-brachytherapy for clinical application are sixfold; (1) the thermal goals (temperature, time and volume) are achievable with currently available technology, (2) the hyperthermia by itself has no detectable toxic effects, (3) thermotolerance appears to play a minor if any role in radiation sensitization, (4) TER of around 2 can be expected, (5) hypoxic fraction may be decreased due to blood flow modification and (6) simultaneous chemotherapy may also be sensitized. Combined LDMH and brachytherapy is a cancer therapy that has established biological rationale and sufficient technical and clinical advancements to be appropriately applied. This modality is ripe for clinical testing.

  3. Photoacoustic-Based-Close-Loop Temperature Control for Nanoparticle Hyperthermia.

    Science.gov (United States)

    Xiaohua, Feng; Fei, Gao; Yuanjin, Zheng

    2015-07-01

    Hyperthermia therapy requires tight temperature control to achieve selective killing of cancerous tissue with minimal damage on surrounding healthy tissues. To this end, accurate temperature monitoring and subsequent heating control are critical. However, an economic, portable, and real-time temperature control solution is currently lacking. To bridge this gap, we present a novel portable close-loop system for hyperthermia temperature control, in which photoacoustic technique is proposed for noninvasive real-time temperature measurement. Exploiting the high sensitivity of photoacoustics, the temperature is monitored with an accuracy of around 0.18 °C and then fed back to a controller implemented on field programmable gate array (FPGA) for temperature control. Dubbed as portable hyperthermia feedback controller (pHFC), it stabilizes the temperature at preset values by regulating the hyperthermia power with a proportional-integral-derivative (PID) algorithm; and to facilitate digital implementation, the pHFC further converts the PID output into switching values (0 and 1) with the pulse width modulation (PWM) algorithm. Proof-of-concept hyperthermia experiments demonstrate that the pHFC system is able to bring the temperature from baseline to predetermined value with an accuracy of 0.3° and a negligible temperature overshoot. The pHFC can potentially be translated to clinical applications with customized hyperthermia system design. This paper can facilitate future efforts in seamless integration of close-loop temperature control solution and various clinical hyperthermia systems.

  4. On the temperature control in self-controlling hyperthermia therapy

    Energy Technology Data Exchange (ETDEWEB)

    Ebrahimi, Mahyar, E-mail: ebrahimi_m@mehr.sharif.ir

    2016-10-15

    In self-controlling hyperthermia therapy, once the desired temperature is reached, the heat generation ceases and overheating is prevented. In order to design a system that generates sufficient heat without thermal ablation of surrounding healthy tissue, a good understanding of temperature distribution and its change with time is imperative. This study is conducted to extend our understanding about the heat generation and transfer, temperature distribution and temperature rise pattern in the tumor and surrounding tissue during self-controlling magnetic hyperthermia. A model consisting of two concentric spheres that represents the tumor and its surrounding tissue is considered and temperature change pattern and temperature distribution in tumor and surrounding tissue are studied. After describing the model and its governing equations and constants precisely, a typical numerical solution of the model is presented. Then it is showed that how different parameters like Curie temperature of nanoparticles, magnetic field amplitude and nanoparticles concentration can affect the temperature change pattern during self-controlling magnetic hyperthermia. The model system herein discussed can be useful to gain insight on the self-controlling magnetic hyperthermia while applied to cancer treatment in real scenario and can be useful for treatment strategy determination. - Highlights: • Temperature change pattern in tumor and surrounding tissue are studied. • The model system herein can be useful for treatment strategy determination. • In the work described herein, emphasis is on the effect of low Curie temperature. • If the equilibrium temperature can be tuned appropriately, the stay time will be infinite.

  5. On the temperature control in self-controlling hyperthermia therapy

    International Nuclear Information System (INIS)

    Ebrahimi, Mahyar

    2016-01-01

    In self-controlling hyperthermia therapy, once the desired temperature is reached, the heat generation ceases and overheating is prevented. In order to design a system that generates sufficient heat without thermal ablation of surrounding healthy tissue, a good understanding of temperature distribution and its change with time is imperative. This study is conducted to extend our understanding about the heat generation and transfer, temperature distribution and temperature rise pattern in the tumor and surrounding tissue during self-controlling magnetic hyperthermia. A model consisting of two concentric spheres that represents the tumor and its surrounding tissue is considered and temperature change pattern and temperature distribution in tumor and surrounding tissue are studied. After describing the model and its governing equations and constants precisely, a typical numerical solution of the model is presented. Then it is showed that how different parameters like Curie temperature of nanoparticles, magnetic field amplitude and nanoparticles concentration can affect the temperature change pattern during self-controlling magnetic hyperthermia. The model system herein discussed can be useful to gain insight on the self-controlling magnetic hyperthermia while applied to cancer treatment in real scenario and can be useful for treatment strategy determination. - Highlights: • Temperature change pattern in tumor and surrounding tissue are studied. • The model system herein can be useful for treatment strategy determination. • In the work described herein, emphasis is on the effect of low Curie temperature. • If the equilibrium temperature can be tuned appropriately, the stay time will be infinite.

  6. Hyperthermia

    International Nuclear Information System (INIS)

    Perez, C.A.; Emami, B.; Nussbaum, G.; Sapareto, S.

    1987-01-01

    The effect on heat on malignant tumors was first reported by Hippocrates. In 1856 another described the disappearance of a soft tissue sarcoma following high fever in a patient with erysipelas. Later, another induced fever by injecting bacterial toxins, and others used localized hyperthermia to produce tumor regression in patients. There were 32 patients with advanced cancer of various types treated with a combination of heat, induced with pyrogenic substances, and x-ray therapy. Twenty-nine of these patients improved for 1 to 6 months. In the past 10 years interest has been rekindled to the clinical application of this modality because numerous papers have indicated that there may be a significant advantage to the use of heat alone or combined with irradiation and cytotoxic drugs to enhance the killing of tumor cells. The clinical use of heat has been hampered by a lack of adequate equipment to deliver effective heat in deep-seated lesions and of thermometry techniques that provide reliable information on heat distribution in target tissues. However, significant progress has been made. About 30% to 50% of patients with solid tumors have recurrences at the primary site. Many of these patients have regional lymph node recurrences. Both failure patterns could be improved if effective radiation sensitizers are developed

  7. Influence of patient mispositioning on SAR distribution and simulated temperature in regional deep hyperthermia

    Science.gov (United States)

    Aklan, Bassim; Gierse, Pia; Hartmann, Josefin; Ott, Oliver J.; Fietkau, Rainer; Bert, Christoph

    2017-06-01

    Patient positioning plays an important role in regional deep hyperthermia to obtain a successful hyperthermia treatment. In this study, the influence of possible patient mispositioning was systematically assessed on specific absorption rate (SAR) and temperature distribution. With a finite difference time domain approach, the SAR and temperature distributions were predicted for six patients at 312 positions. Patient displacements and rotations as well as the combination of both were considered inside the Sigma-Eye applicator. Position sensitivity is assessed for hyperthermia treatment planning -guided steering, which relies on model-based optimization of the SAR and temperature distribution. The evaluation of the patient mispositioning was done with and without optimization. The evaluation without optimization was made by creating a treatment plan for the patient reference position in the center of the applicator and applied for all other positions, while the evaluation with optimization was based on creating an individual plan for each position. The parameter T90 was used for the temperature evaluation, which was defined as the temperature that covers 90% of the gross tumor volume (GTV). Furthermore, the hotspot tumor quotient (HTQ) was used as a goal function to assess the quality of the SAR and temperature distribution. The T90 was shown considerably dependent on the position within the applicator. Without optimization, the T90 was clearly decreased below 40 °C by patient shifts and the combination of shifts and rotations. However, the application of optimization for each positon led to an increase of T90 in the GTV. Position inaccuracies of less than 1 cm in the X-and Y-directions and 2 cm in the Z-direction, resulted in an increase of HTQ of less than 5%, which does not significantly affect the SAR and temperature distribution. Current positioning precision is sufficient in the X (right-left)-direction, but position accuracy is required in the Y-and Z-directions.

  8. Magnetic induction of hyperthermia by a modified self-learning fuzzy temperature controller

    Science.gov (United States)

    Wang, Wei-Cheng; Tai, Cheng-Chi

    2017-07-01

    The aim of this study involved developing a temperature controller for magnetic induction hyperthermia (MIH). A closed-loop controller was applied to track a reference model to guarantee a desired temperature response. The MIH system generated an alternating magnetic field to heat a high magnetic permeability material. This wireless induction heating had few side effects when it was extensively applied to cancer treatment. The effects of hyperthermia strongly depend on the precise control of temperature. However, during the treatment process, the control performance is degraded due to severe perturbations and parameter variations. In this study, a modified self-learning fuzzy logic controller (SLFLC) with a gain tuning mechanism was implemented to obtain high control performance in a wide range of treatment situations. This implementation was performed by appropriately altering the output scaling factor of a fuzzy inverse model to adjust the control rules. In this study, the proposed SLFLC was compared to the classical self-tuning fuzzy logic controller and fuzzy model reference learning control. Additionally, the proposed SLFLC was verified by conducting in vitro experiments with porcine liver. The experimental results indicated that the proposed controller showed greater robustness and excellent adaptability with respect to the temperature control of the MIH system.

  9. Use of extremity insulation during whole body hyperthermia to reduce temperature nonuniformity

    International Nuclear Information System (INIS)

    Thrall, D.E.; Page, R.L.

    1987-01-01

    The author previously documented during whole body hyperthermia in dogs using a radiant heating device that temperature at superficial sites, including tibial bone marrow, falls below systemic arterial temperature during the plateau phase of heating. This may be due to direct heat loss to the environment. Sites where temperature is lower than systemic arterial temperature during the plateau phase may become sanctuary sites where tumor deposits are spared because they do not receive the prescribed thermal dose. In an attempt to decrease temperature nonuniformity and increase thermal dose delivered to such superficial sites, extremity insulation has been employed during whole body hyperthermia in dogs. The author measured temperature at cutaneous and subcutaneous sites and within tibial bone marrow in insulated and noninsulated extremities of dogs undergoing whole body hyperthermia in the radiant heating device. The author found that extremity insulation is effective in reducing extremity temperature nonuniformity. Specific results are presented. Extremity insulation may be necessary during whole body hyperthermia to assure that extremity tumor deposits receive a thermal dose similar to that prescribed for the entire body

  10. The potential for using urinary bladder temperature in monitoring whole body hyperthermia

    International Nuclear Information System (INIS)

    Martin, P.A.; Robins, H.I.; Dennis, W.H.

    1985-01-01

    Urinary bladder, esophageal and rectal temperatures of patients were determined by thermistor thermometry during systemic hyperthermia treatments. When deep temperatures were raised from 37 0 to 41.8 0 , the esophageal temperature increases led those of the bladder and rectum. Throughout the heating phases the paired difference of esophageal and bladder temperatures was significantly greater than zero while the difference between bladder and rectal was less. In this system, urinary bladder temperature is a measure of deep tissue temperature and not a good estimate of arterial blood temperature

  11. Thermal Skin Damage During Reirradiation and Hyperthermia Is Time-Temperature Dependent

    Energy Technology Data Exchange (ETDEWEB)

    Bakker, Akke, E-mail: akke.bakker@amc.uva.nl [Department of Radiation Oncology, Academic Medical Center (AMC), Amsterdam (Netherlands); Kolff, M. Willemijn [Department of Radiation Oncology, Academic Medical Center (AMC), Amsterdam (Netherlands); Holman, Rebecca [Clinical Research Unit, Academic Medical Center (AMC), Amsterdam (Netherlands); Leeuwen, Caspar M. van; Korshuize-van Straten, Linda; Kroon-Oldenhof, Rianne de; Rasch, Coen R.N.; Tienhoven, Geertjan van; Crezee, Hans [Department of Radiation Oncology, Academic Medical Center (AMC), Amsterdam (Netherlands)

    2017-06-01

    Purpose: To investigate the relationship of thermal skin damage (TSD) to time–temperature isoeffect levels for patients with breast cancer recurrence treated with reirradiation plus hyperthermia (reRT + HT), and to investigate whether the treatment history of previous treatments (scar tissue) is a risk factor for TSD. Methods and Materials: In this observational study, temperature characteristics of hyperthermia sessions were analyzed in 262 patients with recurrent breast cancer treated in the AMC between 2010 and 2014 with reirradiation and weekly hyperthermia for 1 hour. Skin temperature was measured using a median of 42 (range, 29-82) measurement points per hyperthermia session. Results: Sixty-eight patients (26%) developed 79 sites of TSD, after the first (n=26), second (n=17), third (n=27), and fourth (n=9) hyperthermia session. Seventy percent of TSD occurred on or near scar tissue. Scar tissue reached higher temperatures than other skin tissue (0.4°C, P<.001). A total of 102 measurement points corresponded to actual TSD sites in 35 of 79 sessions in which TSD developed. Thermal skin damage sites had much higher maximum temperatures than non-TSD sites (2.8°C, P<.001). Generalized linear mixed models showed that the probability of TSD is related to temperature and thermal dose values (P<.001) and that scar tissue is more at risk (odds ratio 0.4, P<.001). Limiting the maximum temperature of a measurement point to 43.7°C would mean that the probability of observing TSD was at most 5%. Conclusion: Thermal skin damage during reRT + HT for recurrent breast cancer was related to higher local temperatures and time–temperature isoeffect levels. Scar tissue reached higher temperatures than other skin tissue, and TSD occurred at lower temperatures and thermal dose values in scar tissue compared with other skin tissue. Indeed, TSD developed often on and around scar tissue from previous surgical procedures.

  12. Effect of SPIO Nanoparticle Concentrations on Temperature Changes for Hyperthermia via MRI

    Directory of Open Access Journals (Sweden)

    Alsayed A. M. Elsherbini

    2013-01-01

    Full Text Available Magnetic nanoparticles (MNPs are being developed for a wide range of biomedical applications. In particular, hyperthermia involves heating the MNPs through exposure to an alternating magnetic field (AMF. These materials offer the potential for selectively by heating cancer tissue locally and at the cellular level. This may be a successful method if there are enough particles in a tumor possessing sufficiently high specific absorption rate (SAR to deposit heat quickly while minimizing thermal damage to surrounding tissue. The current research aim is to study the influence of super paramagnetic iron oxides Fe3O4 (SPIO NPs concentration on the total heat energy dose and the rate of temperature change in AMF to induce hyperthermia in Ehrlich carcinoma cells implanted in female mice. The results demonstrated a linearly increasing trend between these two factors.

  13. Local radiofrequency-induced hyperthermia using CuNi nanoparticles with therapeutically suitable Curie temperature

    International Nuclear Information System (INIS)

    Kuznetsov, Anatoly A.; Leontiev, Vladimir G.; Brukvin, Vladimir A.; Vorozhtsov, Georgy N.; Kogan, Boris Ya.; Shlyakhtin, Oleg A.; Yunin, Alexander M.; Tsybin, Oleg I.; Kuznetsov, Oleg A.

    2007-01-01

    Copper-nickel (CuNi) alloy nanoparticles with Curie temperatures (T c ) from 40 to 60 o C were synthesized by several techniques. Varying the synthesis parameters and post-treatment, as well as separations by size and T c , allow producing mediator nanoparticles for magnetic fluid hyperthermia with parametric feedback temperature control with desired parameters. In vitro and in vivo animal experiments have demonstrated the feasibility of the temperature-controlled heating of the tissue, laden with the particles, by an external alternating magnetic field

  14. Local radiofrequency-induced hyperthermia using CuNi nanoparticles with therapeutically suitable Curie temperature

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, Anatoly A. [Institute of Biochemical Physics, Russian Academy of Sciences (RAS), Moscow 119991 (Russian Federation); Leontiev, Vladimir G. [Institute of Metallurgy, Russian Academy of Sciences (RAS), Moscow 119991 (Russian Federation); Brukvin, Vladimir A. [Institute of Metallurgy, Russian Academy of Sciences (RAS), Moscow 119991 (Russian Federation); Vorozhtsov, Georgy N. [NIOPIK Organic Intermediates and Dyes Institute, Moscow 103787 (Russian Federation); Kogan, Boris Ya. [NIOPIK Organic Intermediates and Dyes Institute, Moscow 103787 (Russian Federation); Shlyakhtin, Oleg A. [Institute of Chemical Physics, Russian Academy of Sciences (RAS), Kosygin St. 4, Moscow 119991 (Russian Federation); Yunin, Alexander M. [Institute of Biochemical Physics, Russian Academy of Sciences (RAS), Moscow 119991 (Russian Federation); Tsybin, Oleg I. [Institute of Metallurgy, Russian Academy of Sciences (RAS), Moscow 119991 (Russian Federation); Kuznetsov, Oleg A. [Institute of Biochemical Physics, Russian Academy of Sciences (RAS), Moscow 119991 (Russian Federation)]. E-mail: kuznetsov_oa@yahoo.com

    2007-04-15

    Copper-nickel (CuNi) alloy nanoparticles with Curie temperatures (T{sub c}) from 40 to 60{sup o}C were synthesized by several techniques. Varying the synthesis parameters and post-treatment, as well as separations by size and T{sub c}, allow producing mediator nanoparticles for magnetic fluid hyperthermia with parametric feedback temperature control with desired parameters. In vitro and in vivo animal experiments have demonstrated the feasibility of the temperature-controlled heating of the tissue, laden with the particles, by an external alternating magnetic field.

  15. Magnetic hyperthermia heating of cobalt ferrite nanoparticles prepared by low temperature ferrous sulfate based method

    Directory of Open Access Journals (Sweden)

    Tejabhiram Yadavalli

    2016-05-01

    Full Text Available A facile low temperature co-precipitation method for the synthesis of crystalline cobalt ferrite nanostructures using ferrous sulfate salt as the precursor has been discussed. The prepared samples were compared with nanoparticles prepared by conventional co-precipitation and hydrothermal methods using ferric nitrate as the precursor. X-ray diffraction studies confirmed the formation of cubic spinel cobalt ferrites when dried at 110 °C as opposed to conventional methods which required higher temperatures/pressure for the formation of the same. Field emission scanning electron microscope studies of these powders revealed the formation of nearly spherical nanostructures in the size range of 20-30 nm which were comparable to those prepared by conventional methods. Magnetic measurements confirmed the ferromagnetic nature of the cobalt ferrites with low magnetic remanance. Further magnetic hyperthermia studies of nanostructures prepared by low temperature method showed a rise in temperature to 50 °C in 600 s.

  16. Stabilization of temperature during magnetic hyperthermia by Ce substituted magnetite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, S.K.; Alla, S.K. [Department of Metallurgical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India); Meena, S.S. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Mandal, R.K. [Department of Metallurgical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India); Prasad, N.K., E-mail: nandkp.met@iitbhu.ac.in [Department of Metallurgical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India)

    2017-07-15

    Highlights: • Ce{sub x}Fe{sub 3−x}O{sub 4} (0.01 ≤ x ≤ 0.5) nanoparticles below 15 nm were synthesized by microwave refluxing method. • The saturation magnetization decreased with increased Ce concentration. • The sample displayed stabilization of temperature near 42 °C during magnetic hyperthermia. - Abstract: We report here magnetic hyperthermia using nanoparticles of Ce{sub x}Fe{sub 3−x}O{sub 4} (x = 0.01, 0.05, 0.1, 0.3 and 0.5) during which temperature was found to be stabilizing near 42 °C. This happens despite of their high saturation magnetization (M{sub S}) and Curie temperature (T{sub C}) values. It was observed that by selecting an appropriate magnetic field the temperature can be rose exactly near the therapeutic temperature and thus it will help to selectively kill the cancerous cells leaving normal cells unaffected. These nanoparticles (size around 8–15 nm) were produced by single step microwave refluxing technique. X-ray diffraction (XRD) analysis demonstrates that samples were essentially single phase except for x = 0.5 sample. The X-ray photoelectron spectroscopy (XPS) study for the samples demonstrated that Ce was present in both Ce{sup 3+} and Ce{sup 4+} states. The saturation magnetization value of the samples decreased sharply from 62 Am{sup 2}/kg for x = 0.01 to 19 Am{sup 2}/kg for x = 0.1. This value further decreased with increased Ce doping.

  17. A Reconstruction Method for the Estimation of Temperatures of Multiple Sources Applied for Nanoparticle-Mediated Hyperthermia

    Directory of Open Access Journals (Sweden)

    Idan Steinberg

    2018-03-01

    Full Text Available Solid malignant tumors are one of the leading causes of death worldwide. Many times complete removal is not possible and alternative methods such as focused hyperthermia are used. Precise control of the hyperthermia process is imperative for the successful application of such treatment. To that end, this research presents a fast method that enables the estimation of deep tissue heat distribution by capturing and processing the transient temperature at the boundary based on a bio-heat transfer model. The theoretical model is rigorously developed and thoroughly validated by a series of experiments. A 10-fold improvement is demonstrated in resolution and visibility on tissue mimicking phantoms. The inverse problem is demonstrated as well with a successful application of the model for imaging deep-tissue embedded heat sources. Thereby, allowing the physician then ability to dynamically evaluate the hyperthermia treatment efficiency in real time.

  18. A Reconstruction Method for the Estimation of Temperatures of Multiple Sources Applied for Nanoparticle-Mediated Hyperthermia.

    Science.gov (United States)

    Steinberg, Idan; Tamir, Gil; Gannot, Israel

    2018-03-16

    Solid malignant tumors are one of the leading causes of death worldwide. Many times complete removal is not possible and alternative methods such as focused hyperthermia are used. Precise control of the hyperthermia process is imperative for the successful application of such treatment. To that end, this research presents a fast method that enables the estimation of deep tissue heat distribution by capturing and processing the transient temperature at the boundary based on a bio-heat transfer model. The theoretical model is rigorously developed and thoroughly validated by a series of experiments. A 10-fold improvement is demonstrated in resolution and visibility on tissue mimicking phantoms. The inverse problem is demonstrated as well with a successful application of the model for imaging deep-tissue embedded heat sources. Thereby, allowing the physician then ability to dynamically evaluate the hyperthermia treatment efficiency in real time.

  19. Measurement of Thermal Conductivity of Porcine Liver in the Temperature Range of Cryotherapy and Hyperthermia (250~315k) by A Thermal Sensor Made of A Micron-Scale Enameled Copper Wire.

    Science.gov (United States)

    Jiang, Z D; Zhao, G; Lu, G R

      BACKGROUND: Cryotherapy and hyperthermia are effective treatments for several diseases, especially for liver cancers. Thermal conductivity is a significant thermal property for the prediction and guidance of surgical procedure. However, the thermal conductivities of organs and tissues, especially over the temperature range of both cryotherapy and hyperthermia are scarce. To provide comprehensive thermal conductivity of liver for both cryotherapy and hyperthermia. A hot probe made of stain steel needle and micron-sized copper wire is used for measurement. To verify data processing, both the least square method and the Monte Carlo inversion method are used to determine the hot probe constants, respectively, with reference materials of water and 29.9 % Ca 2 Cl aqueous solution. Then the thermal conductivities of Hanks solution and pork liver bathed in Hanks solution are measured. The effective length for two methods is nearly the same, but the heat capacity of probe calibrated by the Monte Carlo inversion is temperature dependent. Fairly comprehensive thermal conductivity of porcine liver measured with these two methods in the target temperature range is verified to be similar. We provide an integrated thermal conductivity of liver for cryotherapy and hyperthermia in two methods, and make more accurate predictions possible for surgery. The least square method and the Monte Carlo inversion method have their advantages and disadvantages. The least square method is available for measurement of liquids that not prone to convection or solids in a wide temperature range, while the Monte Carlo inversion method is available for accurate and rapid measurement.

  20. Threshold heating temperature for magnetic hyperthermia: Controlling the heat exchange with the blocking temperature of magnetic nanoparticles

    Science.gov (United States)

    Pimentel, B.; Caraballo-Vivas, R. J.; Checca, N. R.; Zverev, V. I.; Salakhova, R. T.; Makarova, L. A.; Pyatakov, A. P.; Perov, N. S.; Tishin, A. M.; Shtil, A. A.; Rossi, A. L.; Reis, M. S.

    2018-04-01

    La0.75Sr0.25MnO3 nanoparticles with average diameter close to 20.9 nm were synthesized using a sol-gel method. Measurements showed that the heating process stops at the blocking temperaturesignificantly below the Curie temperature. Measurements of Specific Absorption Rate (SAR) as a function of AC magnetic field revealed a superquadratic power law, indicating that, in addition to usual Néel and Brown relaxation, the hysteresis also plays an important role in the mechanism of heating. The ability to control the threshold heating temperature, a low remanent magnetization and a low field needed to achieve the magnetic saturation are the advantages of this material for therapeutic magnetic hyperthermia.

  1. Simulations of adaptive temperature control with self-focused hyperthermia system for tumor treatment.

    Science.gov (United States)

    Hu, Jiwen; Ding, Yajun; Qian, Shengyou; Tang, Xiangde

    2013-01-01

    The control problem in ultrasound therapy is to destroy the tumor tissue while not harming the intervening healthy tissue with a desired temperature elevation. The objective of this research is to present a robust and feasible method to control the temperature distribution and the temperature elevation in treatment region within the prescribed time, which can improve the curative effect and decrease the treatment time for heating large tumor (≥2.0cm in diameter). An adaptive self-tuning-regulator (STR) controller has been introduced into this control method by adding a time factor with a recursive algorithm, and the speed of sound and absorption coefficient of the medium is considered as a function of temperature during heating. The presented control method is tested for a self-focused concave spherical transducer (0.5MHz, 9cm aperture, 8.0cm focal length) through numerical simulations with three control temperatures of 43°C, 50°C and 55°C. The results suggest that this control system has adaptive ability for variable parameters and has a rapid response to the temperature and acoustic power output in the prescribed time for the hyperthermia interest. There is no overshoot during temperature elevation and no oscillation after reaching the desired temperatures. It is found that the same results can be obtained for different frequencies and temperature elevations. This method can obtain an ellipsoid-shaped ablation region, which is meaningful for the treatment of large tumor. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Hyperthermia treatment planning

    International Nuclear Information System (INIS)

    Lagendijk, J.J.W.

    2000-01-01

    The development of hyperthermia, the treatment of tumours with elevated temperatures in the range of 40-44 deg. C with treatment times over 30 min, greatly benefits from the development of hyperthermia treatment planning. This review briefly describes the state of the art in hyperthermia technology, followed by an overview of the developments in hyperthermia treatment planning. It particularly highlights the significant problems encountered with heating realistic tissue volumes and shows how treatment planning can help in designing better heating technology. Hyperthermia treatment planning will ultimately provide information about the actual temperature distributions obtained and thus the tumour control probabilities to be expected. This will improve our understanding of the present clinical results of thermoradiotherapy and thermochemotherapy, and will greatly help both in optimizing clinical heating technology and in designing optimal clinical trials. (author)

  3. Physics responsible for heating efficiency and self-controlled temperature rise of magnetic nanoparticles in magnetic hyperthermia therapy.

    Science.gov (United States)

    Shaterabadi, Zhila; Nabiyouni, Gholamreza; Soleymani, Meysam

    2018-03-01

    Magnetic nanoparticles as heat-generating nanosources in hyperthermia treatment are still faced with many drawbacks for achieving sufficient clinical potential. In this context, increase in heating ability of magnetic nanoparticles in a biologically safe alternating magnetic field and also approach to a precise control on temperature rise are two challenging subjects so that a significant part of researchers' efforts has been devoted to them. Since a deep understanding of Physics concepts of heat generation by magnetic nanoparticles is essential to develop hyperthermia as a cancer treatment with non-adverse side effects, this review focuses on different mechanisms responsible for heat dissipation in a radio frequency magnetic field. Moreover, particular attention is given to ferrite-based nanoparticles because of their suitability in radio frequency magnetic fields. Also, the key role of Curie temperature in suppressing undesired temperature rise is highlighted. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Temperature responsive hydrogel magnetic nanocomposites for hyperthermia and metal extraction applications

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, N. Narayana, E-mail: nagireddynarayana@gmail.com [Center for Advanced Biomaterials for Healthcare, Istituto Italiano di Tecnologia@CRIB, Largo Barsanti e Matteucci 53, 80125 Napoli (Italy); Ravindra, S. [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Johannesburg 1709 (South Africa); Reddy, N. Madhava [Department of Environmental Science, Gates Institute of Technology, NH-7, Gooty, Anantapuram, Andhra Pradesh (India); Rajinikanth, V. [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Johannesburg 1709 (South Africa); Raju, K. Mohana [Synthetic Polymer Laboratory, Department of Polymer Science & Technology, S.K. University, Anantapuram, Andhra Pradesh (India); Vallabhapurapu, Vijaya Srinivasu [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Johannesburg 1709 (South Africa)

    2015-11-15

    The present work deals with the development of temperature and magnetic responsive hydrogel networks based on poly (N-isopropylacrylamide)/acrylamido propane sulfonic acid. The hydrogel matrices are synthesized by polymerizing N-isopropylacrylamide (NIPAM) monomer in the presence of acrylamido propane sulphonicacid (AMPS) using a cross-linker (N,N-methylenebisacrylamide, MBA) and redox initiating system [ammonium persulphate (APS)/tetramethylethylenediamine (TMEDA)]. The magnetic nanoparticles are generated throughout the hydrogel networks using in situ method by incorporating iron ions and subsequent treatment with ammonia. A series of hydrogel-magnetic nanocomposites (HGMNC) are developed by varying AMPS composition. The synthesized hydrogel magnetic nanocomposites (HGMNC) are characterized by using Fourier Transform Infrared (FTIR) Spectroscopy, X-ray diffraction (XRD), Thermal Analyses and Electron Microscopy analysis (Scanning and Transmission Electron Microscope). The metal extraction capacities of the prepared hydrogel (HG) and hydrogel magnetic nanocomposites (HGMNC) were studied at different temperatures. The results suggest that HGMNCs have higher extraction capacity compared to HG and HG loaded iron ions. This data also reveals that the extraction of metals by hydrogel magnetic nanocomposites (HGMNCs) is higher at higher temperatures than room temperature. The prepared HGMNCs are also subjected to hyperthermia (cancer therapy) studies. - Highlights: • We have developed temperature responsive hydrogel magnetic nanocomposites. • Addition of AMPS monomer to this magnetic hydrogel enhances the temperature sensitivity to 40–43 °C. • Similarly the sulfonic groups present in the AMPS units enhances the swelling ratio of magnetic hydrogels. • AMPS acts as good stabilizing agent for nanoparticles in the magnetic nanogel.

  5. Temperature responsive hydrogel magnetic nanocomposites for hyperthermia and metal extraction applications

    International Nuclear Information System (INIS)

    Reddy, N. Narayana; Ravindra, S.; Reddy, N. Madhava; Rajinikanth, V.; Raju, K. Mohana; Vallabhapurapu, Vijaya Srinivasu

    2015-01-01

    The present work deals with the development of temperature and magnetic responsive hydrogel networks based on poly (N-isopropylacrylamide)/acrylamido propane sulfonic acid. The hydrogel matrices are synthesized by polymerizing N-isopropylacrylamide (NIPAM) monomer in the presence of acrylamido propane sulphonicacid (AMPS) using a cross-linker (N,N-methylenebisacrylamide, MBA) and redox initiating system [ammonium persulphate (APS)/tetramethylethylenediamine (TMEDA)]. The magnetic nanoparticles are generated throughout the hydrogel networks using in situ method by incorporating iron ions and subsequent treatment with ammonia. A series of hydrogel-magnetic nanocomposites (HGMNC) are developed by varying AMPS composition. The synthesized hydrogel magnetic nanocomposites (HGMNC) are characterized by using Fourier Transform Infrared (FTIR) Spectroscopy, X-ray diffraction (XRD), Thermal Analyses and Electron Microscopy analysis (Scanning and Transmission Electron Microscope). The metal extraction capacities of the prepared hydrogel (HG) and hydrogel magnetic nanocomposites (HGMNC) were studied at different temperatures. The results suggest that HGMNCs have higher extraction capacity compared to HG and HG loaded iron ions. This data also reveals that the extraction of metals by hydrogel magnetic nanocomposites (HGMNCs) is higher at higher temperatures than room temperature. The prepared HGMNCs are also subjected to hyperthermia (cancer therapy) studies. - Highlights: • We have developed temperature responsive hydrogel magnetic nanocomposites. • Addition of AMPS monomer to this magnetic hydrogel enhances the temperature sensitivity to 40–43 °C. • Similarly the sulfonic groups present in the AMPS units enhances the swelling ratio of magnetic hydrogels. • AMPS acts as good stabilizing agent for nanoparticles in the magnetic nanogel

  6. High-resolution temperature-based optimization for hyperthermia treatment planning

    International Nuclear Information System (INIS)

    Kok, H P; Haaren, P M A van; Kamer, J B Van de; Wiersma, J; Dijk, J D P Van; Crezee, J

    2005-01-01

    In regional hyperthermia, optimization techniques are valuable in order to obtain amplitude/phase settings for the applicators to achieve maximal tumour heating without toxicity to normal tissue. We implemented a temperature-based optimization technique and maximized tumour temperature with constraints on normal tissue temperature to prevent hot spots. E-field distributions are the primary input for the optimization method. Due to computer limitations we are restricted to a resolution of 1 x 1 x 1 cm 3 for E-field calculations, too low for reliable treatment planning. A major problem is the fact that hot spots at low-resolution (LR) do not always correspond to hot spots at high-resolution (HR), and vice versa. Thus, HR temperature-based optimization is necessary for adequate treatment planning and satisfactory results cannot be obtained with LR strategies. To obtain HR power density (PD) distributions from LR E-field calculations, a quasi-static zooming technique has been developed earlier at the UMC Utrecht. However, quasi-static zooming does not preserve phase information and therefore it does not provide the HR E-field information required for direct HR optimization. We combined quasi-static zooming with the optimization method to obtain a millimetre resolution temperature-based optimization strategy. First we performed a LR (1 cm) optimization and used the obtained settings to calculate the HR (2 mm) PD and corresponding HR temperature distribution. Next, we performed a HR optimization using an estimation of the new HR temperature distribution based on previous calculations. This estimation is based on the assumption that the HR and LR temperature distributions, though strongly different, respond in a similar way to amplitude/phase steering. To verify the newly obtained settings, we calculate the corresponding HR temperature distribution. This method was applied to several clinical situations and found to work very well. Deviations of this estimation method for

  7. Effects of Social Interaction and Warm Ambient Temperature on Brain Hyperthermia Induced by the Designer Drugs Methylone and MDPV

    Science.gov (United States)

    Kiyatkin, Eugene A; Kim, Albert H; Wakabayashi, Ken T; Baumann, Michael H; Shaham, Yavin

    2015-01-01

    3,4-Methylenedioxymethcathinone (methylone) and 3,4-methylenedioxypyrovalerone (MDPV) are new drugs of abuse that have gained worldwide popularity. These drugs are structurally similar to 3,4-methylenedioxymethamphetamine (MDMA) and share many of its physiological and behavioral effects in humans, including the development of hyperthermia during acute intoxication. Here, we examined the effects of methylone (1–9 mg/kg, s.c.) or MDPV (0.1–1.0 mg/kg, s.c.) on brain temperature homeostasis in rats maintained in a standard laboratory environment (single-housed in a quiet rest at 22 °C) and under conditions that model human drug use (social interaction and 29 °C ambient temperature). By simultaneously monitoring temperatures in the nucleus accumbens, temporal muscle, and facial skin, we assessed the effects of methylone and MDPV on intra-brain heat production and cutaneous vascular tone, two critical factors that control brain temperature responses. Both methylone and MDPV dose-dependently increased brain temperature, but even at high doses that induced robust locomotor activation, hyperthermia was modest in magnitude (up to ∼2 °C). Both drugs also induced dose-dependent peripheral vasoconstriction, which appears to be a primary mechanism determining the brain hyperthermic responses. In contrast to the powerful potentiation of MDMA-induced hyperthermia by social interaction and warm ambient temperature, such potentiation was absent for methylone and minimal for MDPV. Taken together, despite structural similarities to MDMA, exposure to methylone or MDPV under conditions commonly associated with human drug use does not lead to profound elevations in brain temperature and sustained vasoconstriction, two critical factors associated with MDMA toxicity. PMID:25074640

  8. Hyperthermia quality assurance

    International Nuclear Information System (INIS)

    Shrivastava, P.N.; Paliwal, B.R.

    1984-01-01

    Hyperthermia Physics Center (HPC) operating under contract with the National Cancer Institute is developing a Quality Assurance program for local and regional hyperthermia. The major clinical problem in hyperthermia treatments is that they are extremely difficult to plan, execute, monitor and reproduce. A scientific basis for treatment planning can be established only after ensuring that the performance of heat generating and temperature monitoring systems are reliable. The HPC is presently concentrating on providing uniform NBS traceable calibration of thermometers and evaluation of reproducibility for power generator operation, applicator performance, phanta compositions, system calibrations and personnel shielding. The organizational plan together with recommended evaluation measurements, procedures and criteria are presented

  9. Investigation of temperature dependent magnetic hyperthermia in Fe3O4 ferrofluids

    Science.gov (United States)

    Nemala, Humeshkar Bhaskar

    Magnetic nanoparticles (MNPs) of Fe3O4 and gamma-Fe2O3 have been exploited in the biomedical fields for imaging, targeted drug delivery and magnetic hyperthermia. Magnetic hyperthermia (MHT), the production of heat using ferrofluids, colloidal suspensions of MNPs, in an external AC magnetic field (amplitude, 100-500 Oe and frequency 50 kHz -1MHz), has been explored by many researchers, both in vitro and in vivo, as an alternative viable option to treat cancer. The heat energy generated by Neel and Brownian relaxation processes of the internal magnetic spins could be used to elevate local tissue temperature to about 46 ˚C to arrest cancerous growth. MHT, due to its local nature of heating, when combined with other forms of treatment such as chemotherapy and/or radiation therapy, it could become an effective therapy for cancer treatment. The efficiency of heat production in MHT is quantified by specific absorption rate (SAR), defined as the power output per gram of the MNPs used. In this thesis, ferrofluids consisting of Fe3O4 MNPs of three different sizes (˜ 10 - 13 nm) coated with two different biocompatible surfactants, dextran and polyethylene glycol (PEG), have been investigated. The structural and magnetic characterization of the MNPs were done using XRD, TEM, and DC magnetization measurements. While XRD revealed the crystallite size, TEM provided the information about morphology and physical size distribution of the MNPs. Magnetic measurements of M-vs-H curves for ferrofluids provided information about the saturation magnetization (Ms) and magnetic core size distribution of MNPs. Using MHT measurements, the SAR has been studied as a function of temperature, taking into account the heat loss due to non-adiabatic nature of the experimental set-up. The observed SAR values have been interpreted using the theoretical framework of linear response theory (LRT). We found the SAR values depend on particle size distribution of MNPs, Ms (65-80 emu/g) and the magnetic

  10. Model for hyperthermia with arrays of magnetic nanoparticles: spatial and time temperature distributions in tumor

    Czech Academy of Sciences Publication Activity Database

    Zablotskyy, Vitaliy A.; Lunov, O.; Gómez-Polo, C.

    2010-01-01

    Roč. 10, č. 2 (2010), 690-695 ISSN 1533-4880 Institutional research plan: CEZ:AV0Z10100520 Keywords : interstitial hyperthermia * thermometry * magnetic nanoparticles * radiotherapy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.351, year: 2010

  11. Temperature mapping and thermal dose calculation in combined radiation therapy and 13.56 MHz radiofrequency hyperthermia for tumor treatment

    Science.gov (United States)

    Kim, Jung Kyung; Prasad, Bibin; Kim, Suzy

    2017-02-01

    To evaluate the synergistic effect of radiotherapy and radiofrequency hyperthermia therapy in the treatment of lung and liver cancers, we studied the mechanism of heat absorption and transfer in the tumor using electro-thermal simulation and high-resolution temperature mapping techniques. A realistic tumor-induced mouse anatomy, which was reconstructed and segmented from computed tomography images, was used to determine the thermal distribution in tumors during radiofrequency (RF) heating at 13.56 MHz. An RF electrode was used as a heat source, and computations were performed with the aid of the multiphysics simulation platform Sim4Life. Experiments were carried out on a tumor-mimicking agar phantom and a mouse tumor model to obtain a spatiotemporal temperature map and thermal dose distribution. A high temperature increase was achieved in the tumor from both the computation and measurement, which elucidated that there was selective high-energy absorption in tumor tissue compared to the normal surrounding tissues. The study allows for effective treatment planning for combined radiation and hyperthermia therapy based on the high-resolution temperature mapping and high-precision thermal dose calculation.

  12. Analysis of clinical data to determine the minimum number of sensors required for adequate skin temperature monitoring of superficial hyperthermia treatments.

    Science.gov (United States)

    Bakker, Akke; Holman, Rebecca; Rodrigues, Dario B; Dobšíček Trefná, Hana; Stauffer, Paul R; van Tienhoven, Geertjan; Rasch, Coen R N; Crezee, Hans

    2018-04-27

    Tumor response and treatment toxicity are related to minimum and maximum tissue temperatures during hyperthermia, respectively. Using a large set of clinical data, we analyzed the number of sensors required to adequately monitor skin temperature during superficial hyperthermia treatment of breast cancer patients. Hyperthermia treatments monitored with >60 stationary temperature sensors were selected from a database of patients with recurrent breast cancer treated with re-irradiation (23 × 2 Gy) and hyperthermia using single 434 MHz applicators (effective field size 351-396 cm 2 ). Reduced temperature monitoring schemes involved randomly selected subsets of stationary skin sensors, and another subset simulating continuous thermal mapping of the skin. Temperature differences (ΔT) between subsets and complete sets of sensors were evaluated in terms of overall minimum (T min ) and maximum (T max ) temperature, as well as T90 and T10. Eighty patients were included yielding a total of 400 hyperthermia sessions. Median ΔT was 50 sensors were used. Subsets of sensors result in underestimation of T max up to -2.1 °C (ΔT 95%CI), which decreased to -0.5 °C when >50 sensors were used. Thermal profiles (8-21 probes) yielded a median ΔT 50 stationary sensors or thermal profiles. Adequate coverage of the skin temperature distribution during superficial hyperthermia treatment requires the use of >50 stationary sensors per 400 cm 2 applicator. Thermal mapping is a valid alternative.

  13. Numerical analysis of temperature field improvement with nanoparticles designed to achieve critical power dissipation in magnetic hyperthermia

    Science.gov (United States)

    Tang, Yundong; Flesch, Rodolfo C. C.; Jin, Tao

    2017-07-01

    Magnetic nanoparticle (MNP) hyperthermia is a promising emerging therapy for cancer treatment that is minimally invasive and has been successfully used to treat different types of tumors. The power dissipation of MNPs, which is one of the most important factors during a hyperthermia treatment, is determined by the properties of MNPs and characteristics of the magnetic field. This paper proposes a method based on the finite element analysis for determining the value of the power dissipation of particles (PDP) that can maximize the average temperature of the tumor during treatment and at the same time guarantee that the maximum temperature is within the therapeutic range. The application of the critical PDP value can improve the effectiveness of the treatment since it increases the average temperature in the tumor region while limiting the damage to the healthy tissue that surrounds it. After the critical PDP is determined for a specific model, it is shown how the properties of the MNPs can be chosen to achieve the desired PDP value. The transient behavior of the temperature distribution for two different models considering blood vessels is analyzed as a case study, showing that the presence of a blood vessel inside the tumor region can significantly decrease the uniformity of the temperature field and also increase the treatment duration given its cooling effects. To present a solution that does not depend upon a good model of the tumor region, an alternative method that uses MNPs with low Curie temperature is proposed, given the temperature self-regulating properties of such MNPs. The results demonstrate that the uniformity of the temperature field can be significantly increased by combining the optimization procedure proposed in this paper with the use of low-Curie-temperature MNPs.

  14. Tumor blood flow, pO2, and radioresponse are improved by mild temperature hyperthermia

    International Nuclear Information System (INIS)

    Shakil, Abdus; Griffin, Robert J.; Song, Chang W.

    1997-01-01

    Purpose/Objective: The purpose of this study was to elucidate the changes in tumor blood flow, tumor pO 2 and the radiation response of the tumors caused by mild temperature hyperthermia (MTH). Materials And Methods: Experiments were carried out using the R3230 Adenocarcinoma (R3230 AC tumor), grown subcutaneously in the right hind limbs of male Fischer rats. Tumors were heated once at 40.5 deg.to 43.5 deg.C for 30 or 60 min, or twice at a 24 hr interval. Tumor blood flow and tumor pO 2 were measured immediately after the hyperthermic treatments or after 24 hr using a radioactive microsphere method and by an Eppendorf pO 2 Histograph, respectively. The influence of MTH on the effect of X-irradiation (250 kVp) on this tumor was investigated with tumor growth delay and the in vivo/in vitro excision assay for surviving tumor cell fraction. Results: Tumor blood flow and pO 2 increased upon heating for 30 min at 40.5 deg.C to 43.5 deg.C, but following 60 min heating, the pO 2 was similar to that in control tumors. The tumor blood flow increased about 1.4-fold and the tumor pO 2 increased more than 3 times after 30 min heating at 42.5 deg.C. Therefore, the in vivo/in vitro assay and the growth delay were carried out following treatment with 42.5 deg.C for 30 min. As shown in Table 1, the reduction in surviving fraction by MTH before radiation was markedly greater than that by MTH after radiation. Table 1 also shows that MTH alone caused no growth delay compared to control and while heat after radiation increased the growth delay by 2 days, MTH before radiation increased the growth delay by 5 days compared to radiation alone. Conclusion: The results indicate that MTH is effective in increasing tumor blood flow and oxygenation and that MTH for 30 min at 42.5 deg.C, applied before radiation, significantly improves the radiation response of R3230 AC tumors

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  16. Detection of endotoxins in radiopharmaceutical preparations--I. Comparison of rabbit hyperthermia after intravenous or intrathecal administration of reference endotoxin preparations

    Energy Technology Data Exchange (ETDEWEB)

    Merlin, L; Bruneau, J; Cohen, Y; Michaud, T

    1986-01-01

    The rise of the rabbit internal temperature after endotoxin injection is related to the route of administration. A rise of 1.71 +/- 0.411/sup 0/C is obtained after i.v. injection of 1 ng/kg Escherichia coli 0111.B.4 endotoxin. An increase of 1.93 +/- 0.236/sup 0/C is obtained after suboccipital intrathecal injection of 0.1 ng/kg of the same endotoxin; with the intrathecal route, the hyperthermia is induced by E. coli endotoxin after a dose ten times lower than with i.v. injection as shown by statistical analysis.

  17. Dual reference point temperature interrogating method for distributed temperature sensor

    International Nuclear Information System (INIS)

    Ma, Xin; Ju, Fang; Chang, Jun; Wang, Weijie; Wang, Zongliang

    2013-01-01

    A novel method based on dual temperature reference points is presented to interrogate the temperature in a distributed temperature sensing (DTS) system. This new method is suitable to overcome deficiencies due to the impact of DC offsets and the gain difference in the two signal channels of the sensing system during temperature interrogation. Moreover, this method can in most cases avoid the need to calibrate the gain and DC offsets in the receiver, data acquisition and conversion. An improved temperature interrogation formula is presented and the experimental results show that this method can efficiently estimate the channel amplification and system DC offset, thus improving the system accuracy. (letter)

  18. Specific absorption rate dependence on temperature in magnetic field hyperthermia measured by dynamic hysteresis losses (ac magnetometry)

    Science.gov (United States)

    Garaio, Eneko; Sandre, Olivier; Collantes, Juan-Mari; Garcia, Jose Angel; Mornet, Stéphane; Plazaola, Fernando

    2015-01-01

    Magnetic nanoparticles (NPs) are intensively studied for their potential use for magnetic hyperthermia, a treatment that has passed a phase II clinical trial against severe brain cancer (glioblastoma) at the end of 2011. Their heating power, characterized by the ‘specific absorption rate (SAR)’, is often considered temperature independent in the literature, mainly because of the difficulties that arise from the measurement methodology. Using a dynamic magnetometer presented in a recent paper, we measure here the thermal dependence of SAR for superparamagnetic iron oxide (maghemite) NPs of four different size-ranges corresponding to mean diameters around 12 nm, 14 nm, 15 nm and 16 nm. The article reports a parametrical study extending from 10 to 60 {}^\\circ C in temperature, from 75 to 1031 kHz in frequency, and from 2 to 24 kA m-1 in magnetic field strength. It was observed that SAR values of smaller NPs decrease with temperature whereas for the larger sample (16 nm) SAR values increase with temperature. The measured variation of SAR with temperature is frequency dependent. This behaviour is fully explained within the scope of linear response theory based on Néel and Brown relaxation processes, using independent magnetic measurements of the specific magnetization and the magnetic anisotropy constant. A good quantitative agreement between experimental values and theoretical values is confirmed in a tri-dimensional space that uses as coordinates the field strength, the frequency and the temperature.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-15

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

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

    Science.gov (United States)

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

    2017-06-01

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

  1. Biological effects of hyperthermia

    International Nuclear Information System (INIS)

    Okumura, Hiroshi

    1980-01-01

    Biological effects of hyperthermia and application of hyperthermia to cancer therapy were outlined. As to independent effects of hyperthermia, heat sensitivity of cancer cells, targets of hyperthermia, thermal tolerance of cancer cells, effects of pH on hyperthermic cell survival, effects of hyperthermia on normal tissues, and possibility of clinical application of hyperthermia were described. Combined effect of hyperthermia and x-irradiation to enhance radiosensitivity of cancer cells, its mechanism, effects of oxygen on cancer cells treated with hyperthermia and irradiation, and therapeutic ratio of combined hyperthermia and irradiation were also described. Finally, sensitizers were mentioned. (Tsunoda, M.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-06-15

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

  3. Temperature mapping of laser-induced hyperthermia in an ocular phantom using magnetic resonance thermography.

    Science.gov (United States)

    Maswadi, Saher M; Dodd, Stephen J; Gao, Jia-Hong; Glickman, Randolph D

    2004-01-01

    Laser-induced heating in an ocular phantom is measured with magnetic resonance thermography (MRT) using temperature-dependent phase changes in proton resonance frequency. The ocular phantom contains a layer of melanosomes isolated from bovine retinal pigment epithelium. The phantom is heated by the 806-nm output of a continuous wave diode laser with an irradiance of 2.4 to 21.6 W/cm2 in a beam radius of 0.8 or 2.4 mm, depending on the experiment. MRT is performed with a 2 T magnet, and a two-turn, 6-cm-diam, circular radio frequency coil. Two-dimensional temperature gradients are measured within the plane of the melanin layer, as well as normal to it, with a temperature resolution of 1 degrees C or better. The temperature gradients extending within the melanin layer are broader than those orthogonal to the layer, consistent with the higher optical absorption and consequent heating in the melanin. The temperature gradients in the phantom measured by MRT closely approximate the predictions of a classical heat diffusion model. Three-dimensional temperature maps with a spatial resolution of 0.25 mm in all directions are also made. Although the temporal resolution is limited in the prototype system (22.9 s for a single image "slice"), improvements in future implementations are likely. These results indicate that MRT has sufficient spatial and temperature resolution to monitor target tissue temperature during transpupillary thermotherapy in the human eye.

  4. Hyperthermia and radiotherapy

    International Nuclear Information System (INIS)

    Dietzel, F.

    1979-01-01

    Of decisive importance for superadditive enhancement is the close temporal correlation of hyperthermia and radiotherapy. It is recommended to first irradiate and then use heat treatment in order to ensure that dividable tumour cells are irradiated before hyperthermia. To achieve an optimal enhancing effect, temperatures of appr. 42 0 are sufficient. In order to be able to neglect temperature regulation and convection effects, hyperthermia for clinical use must be carried out in doses high enough to ensure that it can be finished within 3-4 minutes. It is necessary to make efforts to find out which forms of application can be realised in order to reach deeper tissue regions, thus making possible at least a half-depth-therapy. Up to day, only the 2 cm near to the surface can be heated in a sufficiently homogeneous way. In the FRG, there are more than 200 high-volt-therapy systems, including electron accelerators and telegamma systems. This is a dense network of radiation-therapeutical supply. An improved therapy effect of loose ionising rays which, with the help of the hypertherming, would almost be equal to irradiation with high ionisation density, is not only of scientific interest, but also of high interest for public health. (orig./MG) 891 MG/orig.- 892 RDG [de

  5. Hyperthermia and radiotherapy

    International Nuclear Information System (INIS)

    Fitspatrick, C.

    1990-01-01

    Hyperthermia and radiotherapy have for long been used to assist in the control of tumours, either as separate entities, or, in a combined treatment scheme. This paper outlines why hyperthermia works, thermal dose and the considerations required in the timing when hyperthermia is combined with radiotherapy. Previously reported results for hyperthermia and radiotherapy used together are also presented. 8 refs., 8 tabs

  6. Combined effects of x irradiation and hyperthermia on CHO cells for various temperatures and orders of application

    International Nuclear Information System (INIS)

    Sapareto, S.A.; Hopwood, L.E.; Dewey, W.C.

    1978-01-01

    The survival of CHO cells to hyperthermic treatment combined with radiation indicates that heat given either immediately before or immediately after irradiation radiosensitizers S-phase cells more than G1 cells, thus resulting in similar absolute levels of survival for each phase. No difference in effect was observed for different temperatures (42.0 to 45.5 0 C) applied before irradiation in either G1 or S when times of heating were adjusted to obtain the same survival (0.5 to 0.6) from heat alone. When heat was administered after irradiation and the time between treatments was increased, repair during G1 of radiation damage which interacted with subsequent heat damage occurred over a 2-hr period. Survival increased from a synergistic level to an independent level with kinetics similar to those seen for repair between split x-ray doses. For this experiment, the heat treatments were administered at either 42.5 or 45.5 0 C with times of heating adjusted to obtain the same survival (0.15) from heat alone. When cells were treated similarly in S phase using either 42.5 or 45.5 0 C (survival from heat alone was 0.2), recovery from a synergistic level of survival was similar to that observed in G1; however, survival did not reach an independent level by 120 min between treatments. When relatively sublethal heat doses at either 42.5 or 45.5 0 C were applied either before, during, or after irradiation, the maximum reduction in survival of asynchronous cells occurred when heat was present during and immediately following irradation, presumably due to heat increasing the fixation of radiation damage. A sixfold difference in survival was observed with about a 5-min change in the timing of radiation with respect to heating. This sensitivity of survival to changes in protocol may have considerable implications in the combined use of hyperthermia and radiation for cancer therapy

  7. On the improvement of regional hyperthermia treatment

    NARCIS (Netherlands)

    Kroeze, Hugo

    2002-01-01

    Hyperthermia is an adjuvant treatment modality to radiotherapy and/or chemotherapy, with the aim of increasing the tumour killing effect of the treatment. It involves the elevation of the tumour temperature to ~ 42oC. Radiofrequent heating is a practical method for hyperthermia: a number of

  8. The correlation between the rise of the tumor temperature during the hyperthermia treatment and the tumor blood flow measured by dynamic CT and 15O gas-positron emission tomography

    International Nuclear Information System (INIS)

    Hattori, Hideyuki

    1993-01-01

    This study was designed to determine the correlation between the rise of tumor temperature during hyperthermia treatment and the blood flow of the tumors measured by dynamic CT (DCT) and 15 O gas-positron emission tomography. In this report, we observed 20 patients with malignant tumors which underwent hyperthermia treatment. In each case, the temperature of the tumor was monitored with a photofiber sensor. DCT's and 15 O gas-positron emission tomographies were applied before the hyperthermia treatment. During the DCT, the tumor blood flow of each tumor was estimated by analyzing the time-dependent activity curve after a bolus injection. During the 15 O gas-positron emission tomography, the tumor blood flow was estimated by the C 15 O 2 -steady-state method. The value of the tumor blood flow estimated by DCT were proportional to those calculated by the 15 O gas-positron emission tomography. These values were inversely proportional to the rise of the temperature of the tumors during hyperthermia treatment. Our results imply that DCT as well as the 15 O gas-positron emission tomography can be used for the prediction of the tumor temperature rise during the hyperthermia treatment. (author)

  9. Exercise hyperthermia as a factor limiting physical performance - Temperature effect on muscle metabolism

    Science.gov (United States)

    Kozlowski, S.; Brzezinska, Z.; Kruk, B.; Kaciuba-Uscilko, H.; Greenleaf, J. E.

    1985-01-01

    The effect of trunk cooling on the muscle contents of ATP, ADP, AMP, creatine phosphate (CrP), and creatine, as well as of glycogen, some glycolytic intermediates, pyruvate, and lactate were assessed in 11 fasted dogs exercised at 20 C on treadmill to exhaustion. Without cooling, dogs were able to run 57 min, and their rectal (Tre) and muscle (Tm) temperatures increased to 41.8 and 43.0 C, respectively. Cooling with ice packs prolonged the ability to run by 45 percent, and resulted in lower Tre (by 1.1 C) and Tm (by 1.2 C). Depletion of muscle content of total high-energy phosphates (ATP + CrP) and glycogen, and increases in contents of AMP, pyruvate, and lactate were lower in cooled dogs than in non-cooled dogs. The muscle content of lactiate correlated positively with TM. These results indicate that hypothermia accelerates glycolysis, and shifts the equilibrium between high- and low-energy phosphates in favor of the latter. The adverse effect of hypothermia on muscle metabolism may be relevant to the limitation of endurance.

  10. Neurological complications after 434 MHz microwave hyperthermia of the rat lumbar region including the spinal cord

    NARCIS (Netherlands)

    Franken, N. A.; de Vrind, H. H.; Sminia, P.; Haveman, J.; Troost, D.; Gonzalez Gonzalez, D.

    1992-01-01

    Hyperthermia was applied in the region of the vertebral column from the second to the fifth lumbar vertebra using a ring-shaped 434 MHz microwave radiator. In all experiments temperatures were measured at a 'reference' thermocouple which was placed against the fourth lumbar vertebra. After 60 min of

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

    Science.gov (United States)

    Tang, Yundong; Flesch, Rodolfo C. C.; Jin, Tao

    2017-06-01

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

  12. Malignant hyperthermia

    Directory of Open Access Journals (Sweden)

    Pollock Neil

    2007-04-01

    Full Text Available Abstract Malignant hyperthermia (MH is a pharmacogenetic disorder of skeletal muscle that presents as a hypermetabolic response to potent volatile anesthetic gases such as halothane, sevoflurane, desflurane and the depolarizing muscle relaxant succinylcholine, and rarely, in humans, to stresses such as vigorous exercise and heat. The incidence of MH reactions ranges from 1:5,000 to 1:50,000–100,000 anesthesias. However, the prevalence of the genetic abnormalities may be as great as one in 3,000 individuals. MH affects humans, certain pig breeds, dogs, horses, and probably other animals. The classic signs of MH include hyperthermia to marked degree, tachycardia, tachypnea, increased carbon dioxide production, increased oxygen consumption, acidosis, muscle rigidity, and rhabdomyolysis, all related to a hypermetabolic response. The syndrome is likely to be fatal if untreated. Early recognition of the signs of MH, specifically elevation of end-expired carbon dioxide, provides the clinical diagnostic clues. In humans the syndrome is inherited in autosomal dominant pattern, while in pigs in autosomal recessive. The pathophysiologic changes of MH are due to uncontrolled rise of myoplasmic calcium, which activates biochemical processes related to muscle activation. Due to ATP depletion, the muscle membrane integrity is compromised leading to hyperkalemia and rhabdomyolysis. In most cases, the syndrome is caused by a defect in the ryanodine receptor. Over 90 mutations have been identified in the RYR-1 gene located on chromosome 19q13.1, and at least 25 are causal for MH. Diagnostic testing relies on assessing the in vitro contracture response of biopsied muscle to halothane, caffeine, and other drugs. Elucidation of the genetic changes has led to the introduction, on a limited basis so far, of genetic testing for susceptibility to MH. As the sensitivity of genetic testing increases, molecular genetics will be used for identifying those at risk with

  13. Can we settle with single-band radiometric temperature monitoring during hyperthermia treatment of chestwall recurrence of breast cancer using a dual-mode transceiving applicator?

    Energy Technology Data Exchange (ETDEWEB)

    Jacobsen, Svein [Electrical Engineering Group, Department of Physics and Technology, Faculty of Science, University of Tromsoe, N-9037 Tromsoe (Norway); Stauffer, Paul R [Radiation Oncology Department, University of California at San Francisco, San Francisco, CA 94143 (United States)

    2007-02-21

    The total thermal dose that can be delivered during hyperthermia treatments is frequently limited by temperature heterogeneities in the heated tissue volume. Reliable temperature information on the heated area is thus vital for the optimization of clinical dosimetry. Microwave radiometry has been proposed as an accurate, quick and painless temperature sensing technique for biological tissue. Advantages include the ability to sense volume-averaged temperatures from subsurface tissue non-invasively, rather than with a limited set of point measurements typical of implanted temperature probes. We present a procedure to estimate the maximum tissue temperature from a single radiometric brightness temperature which is based on a numerical simulation of 3D tissue temperature distributions induced by microwave heating at 915 MHz. The temperature retrieval scheme is evaluated against errors arising from unknown variations in thermal, electromagnetic and design model parameters. Whereas realistic deviations from base values of dielectric and thermal parameters have only marginal impact on performance, pronounced deviations in estimated maximum tissue temperature are observed for unanticipated variations of the temperature or thickness of the bolus compartment. The need to pay particular attention to these latter applicator construction parameters in future clinical implementation of the thermometric method is emphasized.

  14. Can we settle with single-band radiometric temperature monitoring during hyperthermia treatment of chestwall recurrence of breast cancer using a dual-mode transceiving applicator?

    International Nuclear Information System (INIS)

    Jacobsen, Svein; Stauffer, Paul R

    2007-01-01

    The total thermal dose that can be delivered during hyperthermia treatments is frequently limited by temperature heterogeneities in the heated tissue volume. Reliable temperature information on the heated area is thus vital for the optimization of clinical dosimetry. Microwave radiometry has been proposed as an accurate, quick and painless temperature sensing technique for biological tissue. Advantages include the ability to sense volume-averaged temperatures from subsurface tissue non-invasively, rather than with a limited set of point measurements typical of implanted temperature probes. We present a procedure to estimate the maximum tissue temperature from a single radiometric brightness temperature which is based on a numerical simulation of 3D tissue temperature distributions induced by microwave heating at 915 MHz. The temperature retrieval scheme is evaluated against errors arising from unknown variations in thermal, electromagnetic and design model parameters. Whereas realistic deviations from base values of dielectric and thermal parameters have only marginal impact on performance, pronounced deviations in estimated maximum tissue temperature are observed for unanticipated variations of the temperature or thickness of the bolus compartment. The need to pay particular attention to these latter applicator construction parameters in future clinical implementation of the thermometric method is emphasized

  15. Regional hyperthermia of the liver

    International Nuclear Information System (INIS)

    Petrovich, Z.; Langholz, B.; Astrahan, M.; Emami, B.; Oleson, J.R.

    1989-01-01

    From 1981 through 1986, 49 patients with metastatic liver tumors received deep regional hyperthermia in phase I protocols in six major medical centers in the United States. Adenocarcinoma was seen in 80% of patients with colon as the primary site in 26%. The remaining patients had the following histological diagnoses: Soft tissue sarcoma in seven, malignant melanoma in two and transitional cell carcinoma in one. Deep regional hyperthermia treatments with a BSD-1000 annular phased array were given once or twice a week with a total of 167 treatment sessions, mean 3.4 (range 1 to 8). In addition to deep regional hyperthermia, 17 patients received radiotherapy, and 14 received chemotherapy. The median survival for all patients was 25 weeks. Complete response was obtained in two patients and partial response in four patients. An additional ten patients had nominal response. There was no complete or partial response among the 14 hyperthermia alone treated patients. Of the 26 patients who presented with severe pain, five had complete pain relief, five had partial relief and the majority had a lesser degree of pain relief or no pain relief. Acute treatment toxicity consisted of pain in ten, systemic temperature increase to 39 0 C in four tachycardia in two, claustrophobia in one. The majority of patients did not experience acute toxicity. No late toxicity was recorded in this group of 49 patients. (orig./MG)

  16. An overview of interstitial brachytherapy and hyperthermia

    International Nuclear Information System (INIS)

    Brandt, B.B.; Harney, J.

    1989-01-01

    Interstitial thermoradiotherapy, an experimental cancer treatment that combines interstitial radiation implants (brachytherapy) and interstitial hyperthermia, is in the early stages of investigation. In accordance with the procedure used in a current national trial protocol, a 60-minute hyperthermia treatment is administered after catheters are placed into the tumor area while the patient is under general anesthesia. This is immediately followed by loading of radioactive Iridium-192 seeds into the catheters for a defined period of time. Once the prescribed radiation dose is delivered, the radioactive sources are removed and a second, 60-minute hyperthermia treatment is administered. Clinical trials with hyperthermia in combination with radiation have increased in recent years. Nurses caring for these patients need to become more knowledgeable about this investigational therapy. This paper provides an overview of the biologic rationale for this therapy, as well as a description of the delivery method and clinical application. Specific related nursing interventions are defined in a nursing protocol.23 references

  17. Use of the vasodilator sodium nitroprusside during local hyperthermia: effects on tumor temperature and tumor response in a rat tumor model

    International Nuclear Information System (INIS)

    Krossnes, Baard Kronen; Mella, Olav; Dahl, Olav

    1996-01-01

    Purpose: The effect of a decrease in the mean arterial blood pressure (MAP) induced by sodium nitroprusside (SNP) on the tumor temperature during hyperthermia (HT), and on the cytotoxic effect of HT, was studied in the BT 4 An tumor transplanted to the hind limb of BD IX rats. Experiments with two different anesthetics, pentobarbital and the midazolam/fentanyl/fluanisone combination (MFF), were performed to secure reliable conclusions. Methods and Materials: In the tumor response experiments local waterbath HT at 44.0 deg. C was given for 60 min. Sodium nitroprusside was administered as a continuous intravenous infusion to lower the MAP to 60 or 80 mmHg during HT. In two other experiments the temperature at the base of the tumor during HT was measured before and during SNP infusion. In animals without tumor the temperature was measured subcutaneously on the foot during HT with or without SNP-induced hypotension. Results: When SNP was given to lower the MAP to 60 mmHg during HT in MFF anesthetized animals, the median tumor growth time (TGT) was 70 days, compared to 14.5 days in the HT alone group. The corresponding figures were 127 and 12.1 days with pentobarbital anesthesia. In the HT + SNP group, more than 40% cure was observed in both experiments. No cures were seen in any of the other groups. Hyperthermia alone prolonged the TGT slightly, whereas SNP given alone had no effect, compared to controls. When the MAP was lowered to 80 mmHg by SNP infusion during HT (MFF anesthesia), the median TGT was 19.9 days, which was significantly longer than that in the HT alone group (10.9 days). In the MAP range from 60 to 120 mmHg, a nearly linear relationship between the MAP and the tumor temperature was found during HT in MFF anesthetized animals. With both anesthetics, the median temperature at the base of the tumor was about 0.8 deg. C higher during HT when the MAP was lowered to 60 mmHg by SNP. In animals without tumors, the temperature subcutaneously on the foot was 0

  18. Online Adaptive Hyperthermia Treatment Planning During Locoregional Heating to Suppress Treatment-Limiting Hot Spots

    NARCIS (Netherlands)

    Kok, H. Petra; Korshuize-van Straten, Linda; Bakker, Akke; de Kroon-Oldenhof, Rianne; Geijsen, Elisabeth D.; Stalpers, Lukas J. A.; Crezee, Johannes

    2017-01-01

    Adequate tumor temperatures during hyperthermia are essential for good clinical response, but excessive heating of normal tissue should be avoided. This makes locoregional heating using phased array systems technically challenging. Online application of hyperthermia treatment planning could help to

  19. Outcomes after environmental hyperthermia.

    Science.gov (United States)

    LoVecchio, Frank; Pizon, Anthony F; Berrett, Christopher; Balls, Adam

    2007-05-01

    This study was conducted to describe the characteristics and outcomes of patients who presented to the emergency department (ED) with presumed environmental hyperthermia. A retrospective chart review was performed in 2 institutions with patients who were seen in the ED and had a discharge diagnosis of hyperthermia, heat stroke, heat exhaustion, or heat cramps. Exclusion criteria were an alternative diagnosis potentially explaining the hyperthermia (pneumonia, etc). Research assistants, who were blinded to the purpose of the study, performed a systematic chart review after a structured training session. If necessary, a third reviewer acted as a tiebreaker. Data regarding patient demographics, comorbidities, vital signs, laboratory results, and short-term outcome were collected. Data were analyzed with Excel and STATA software. We enrolled 52 patients with a mean age of 42.6 years (range, 0.4-81 years) from August 1, 2003 to August 31, 2005. The mean high daily temperature was 103.6 degrees F (range, 88-118 degrees F). At presentation, the mean body temperature was 105.1 degrees F (range, 100.2-111.2 degrees F) and the Glasgow Coma Scale score was less than 14 in 36 (69.2%) patients. Laboratory results demonstrated that 21 (40.4%) patients had a creatinine level of more than 1.5 mg/dL, 35 (67.3%) patients had a creatine kinase (CK) of more than 200 U/L, 30 patients (57.7%) had a prothrombin time of more than 13 seconds, 29 (55.8%) patients had an aspartate aminotransferase (AST) of more than 45 U/L, and only 3 patients (5.7%) had a glucose of less than 60 mg/dL. Ethanol or illicit drugs were involved in 18 (34.6%) cases. The mean hospital stay was 4.7 days (range, 1-30 days), and there were 15 deaths (28.8%). A kappa score for interreviewer reliability was 0.69. Major limitations were the retrospective nature and lack of homogeneity in patient evaluation and test ordering. Hyperthermic patients with higher initial temperatures, hypotension, or low Glasgow Coma Scale

  20. Stable solid state reference electrodes for high temperature water chemistry

    International Nuclear Information System (INIS)

    Jayaweera, P.; Millett, P.J.

    1995-01-01

    A solid state electrode capable of providing a stable reference potential under a wide range of temperatures and chemical conditions has been demonstrated. The electrode consists of a zirconia or yttria-stabilized zirconia tube packed with an inorganic polymer electrolyte and a silver/silver chloride sensing element. The sensing element is maintained near room temperature by a passive cooling heat sink. The electrode stability was demonstrated by testing it in high temperature (280 C) aqueous solutions over extended periods of time. This reference electrode is useful in many applications, particularly for monitoring the chemistry in nuclear and fossil power plants

  1. CMOS bandgap references and temperature sensors and their applications

    NARCIS (Netherlands)

    Wang, G.

    2005-01-01

    Two main parts have been presented in this thesis: device characterization and circuit. In integrated bandgap references and temperature sensors, the IC(VBE, characteristics of bipolar transistors are used to generate the basic signals with high accuracy. To investigate the possibilities to

  2. Hyperthermia stimulates HIV-1 replication.

    Directory of Open Access Journals (Sweden)

    Ferdinand Roesch

    Full Text Available HIV-infected individuals may experience fever episodes. Fever is an elevation of the body temperature accompanied by inflammation. It is usually beneficial for the host through enhancement of immunological defenses. In cultures, transient non-physiological heat shock (42-45°C and Heat Shock Proteins (HSPs modulate HIV-1 replication, through poorly defined mechanisms. The effect of physiological hyperthermia (38-40°C on HIV-1 infection has not been extensively investigated. Here, we show that culturing primary CD4+ T lymphocytes and cell lines at a fever-like temperature (39.5°C increased the efficiency of HIV-1 replication by 2 to 7 fold. Hyperthermia did not facilitate viral entry nor reverse transcription, but increased Tat transactivation of the LTR viral promoter. Hyperthermia also boosted HIV-1 reactivation in a model of latently-infected cells. By imaging HIV-1 transcription, we further show that Hsp90 co-localized with actively transcribing provirus, and this phenomenon was enhanced at 39.5°C. The Hsp90 inhibitor 17-AAG abrogated the increase of HIV-1 replication in hyperthermic cells. Altogether, our results indicate that fever may directly stimulate HIV-1 replication, in a process involving Hsp90 and facilitation of Tat-mediated LTR activity.

  3. Hyperthermia for the Treatment of Locally Advanced Cervix Cancer

    NARCIS (Netherlands)

    M. Franckena (Martine)

    2010-01-01

    textabstract(English): There is a strong biological rationale for the use of hyperthermia as an oncological treatment modality. Fifteen randomized trials have shown significant improvement in clinical outcome when hyperthermia was added to radiotherapy, chemotherapy or both. At temperatures ≥ 40

  4. Investigation of magnetic properties of Fe{sub 3}O{sub 4} nanoparticles using temperature dependent magnetic hyperthermia in ferrofluids

    Energy Technology Data Exchange (ETDEWEB)

    Nemala, H.; Thakur, J. S.; Lawes, G.; Naik, R., E-mail: rnaik@wayne.edu [Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48202 (United States); Naik, V. M. [Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan 48128 (United States); Vaishnava, P. P. [Department of Physics, Kettering University, Flint, Michigan 48504 (United States)

    2014-07-21

    Rate of heat generated by magnetic nanoparticles in a ferrofluid is affected by their magnetic properties, temperature, and viscosity of the carrier liquid. We have investigated temperature dependent magnetic hyperthermia in ferrofluids, consisting of dextran coated superparamagnetic Fe{sub 3}O{sub 4} nanoparticles, subjected to external magnetic fields of various frequencies (188–375 kHz) and amplitudes (140–235 Oe). Transmission electron microscopy measurements show that the nanoparticles are polydispersed with a mean diameter of 13.8 ± 3.1 nm. The fitting of experimental dc magnetization data to a standard Langevin function incorporating particle size distribution yields a mean diameter of 10.6 ± 1.2 nm, and a reduced saturation magnetization (∼65 emu/g) compared to the bulk value of Fe{sub 3}O{sub 4} (∼95 emu/g). This is due to the presence of a finite surface layer (∼1 nm thickness) of non-aligned spins surrounding the ferromagnetically aligned Fe{sub 3}O{sub 4} core. We found the specific absorption rate, measured as power absorbed per gram of iron oxide nanoparticles, decreases monotonically with increasing temperature for all values of magnetic field and frequency. Using the size distribution of magnetic nanoparticles estimated from the magnetization measurements, we have fitted the specific absorption rate versus temperature data using a linear response theory and relaxation dissipation mechanisms to determine the value of magnetic anisotropy constant (28 ± 2 kJ/m{sup 3}) of Fe{sub 3}O{sub 4} nanoparticles.

  5. A survey of reference electrodes for high temperature waters

    International Nuclear Information System (INIS)

    Molander, A.; Eriksson, Sture; Pein, K.

    2000-11-01

    In nuclear power plants, corrosion potential measurements are used to follow the conditions for different corrosion types in reactor systems, particularly IGSCC in BWRs. The goal of this work has been to give a survey of reference electrodes for high temperature water, both those that are used for nuclear environments and those that are judged to possible future development. The reference electrodes that are used today in nuclear power plants for corrosion potential measurements are of three types. Silver chloride electrodes, membrane electrodes and platinum electrodes (hydrogen electrodes). The principals for their function is described as well as the conversion of measured potentials to the SHE scale (Standard Hydrogen Electrode). Silver chloride electrodes consist of an inner reference system of silver chloride in equilibrium with a chloride solution. The silver chloride electrode is the most common reference electrode and can be used in several different systems. Platinum electrodes are usually more robust and are particularly suitable to use in BWR environment to follow the hydrogen dosage, but have limitations at low and no hydrogen dosage. Ceramic membrane electrodes can be with different types of internal reference system. They were originally developed for pH measurements in high temperature water. If pH is constant, the membrane electrode can be used as reference electrode. A survey of ceramic reference electrodes for high temperature water is given. A ceramic membrane of the type used works as an oxygen conductor, so the potential and pH in surrounding medium is in equilibrium with the internal reference system. A survey of the lately development of electrodes is presented in order to explain why the different types of electrodes are developed as well as to give a background to the possibilities and limitations with the different electrodes. Possibilities of future development of electrodes are also given. For measurements at low or no hydrogen dosage

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-15

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

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

    Science.gov (United States)

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

    2014-12-01

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

  9. Type T reference function suitability for low temperature applications

    Science.gov (United States)

    Dowell, D.

    2013-09-01

    Type T thermocouples are commonly used in industrial measurement applications due to their accuracy relative to other thermocouple types, low cost, and the ready availability of measurement equipment. Type T thermocouples are very effective when used in differential measurements, as there is no cold junction compensation necessary for the connections to the measurement equipment. Type T's published accuracy specifications result in its frequent use in low temperature applications. An examination of over 328 samples from a number of manufacturers has been completed for this investigation. Samples were compared to a Standard Platinum Resistance Thermometer (SPRT) at the LN2 boiling point along with four other standardized measurement points using a characterized ice point reference, low-thermal EMF scanner and an 8.5 digit multimeter, and the data compiled and analyzed. The test points were approximately -196 °C, -75 °C, 0 °C, +100 °C, and +200 °C. These data show an anomaly in the conformance to the reference functions where the reference functions meet at 0 °C. Additionally, in the temperature region between -100 °C to -200 °C, a positive offset of up to 5.4 °C exists between the reference function equations published in the ASTM E230-06 for the nitrogen point and the measured response of the actual wire. This paper will examine the historical and technological reasons for this anomaly in the both the ASTM and IEC reference functions. At the request of the author and the Proceedings Editor the above article has been replaced with a corrected version. The original PDF file supplied to AIP Publishing contained several figures with missing information/characters—caused by processes used to generate the PDF file. All figures were affected by this error. The article has been replaced and these figures now display correctly. The corrected article was published on 7 November 2013.

  10. Ultrasonic system for hyperthermia

    International Nuclear Information System (INIS)

    Seppi, E.J.; Shapiro, E.G.; Zitelli, L.T.

    1985-01-01

    A system using ultrasound has been developed for hyperthermia application. It consists of a water bed containing a large ultrasound transducer array for heat application, an annular imaging transducer for alignment and treatment monitoring, and a 30-channel monitoring system for invasive temperature measurements. The heat applicator array contains 30 transducers mounted in a hexagonal configuration. Four subsets of transducers in the array can be remotely mechanically driven in such a way as to allow control of the distribution and diameter of ultrasound power at the effective focus of the array. The array can be remotely translated in three dimensions and can be rotated about its axis of symmetry. These motions allow positioning of the focal area of the array at the desired location. Each transducer of the array is powered by an individual amplifier and can be controlled in intensity and phase. The system can operate at variable ultrasound frequencies. An imaging transducer located at the center of the heat applicator array is used to collect data for ultrasound imaging and other purposes. Ultrasound images are displayed along with marks indicating the location of the heat applicator focal region for setup and for monitoring during treatment. The entire system is under computer control. This allows for operator ease in the control of the numerous parameters involved in the operation of the system

  11. Hyperthermia, immunity and metastases

    International Nuclear Information System (INIS)

    Lopatin, V.F.

    1983-01-01

    The analysis of literature data concerning local hyperthermia effects shows that temperatures over 41-42 deg C (in the whole tumor volume), causing tumor growth inhibition and cell injury, can change antigenic nature of a malignant tissue. The tumor injured by thermal effect is able probably the full length of time of injured tissue resorption to maintain at a sufficiently high level antitumoral immunity and lay obstacles to emergence of metastases or even cause regression of those tumoral foci which have not been exposed to direct effect of the injuring agent. The facts of tumoral foci regression take place also upon radiation effect which is associated as well with participation of immune mechanisms. In.experiments with animals an essential increase of immunogenic character of malignant cells exposed to ionizing radiation effect has been observed. It follows that radiation injury of tumoral tissue as well as thermal one is able to stimulate antitumoral immunity and reduce the probability of emergence of metastases. But in case of radiotherapy immunosuppression effect of ionizing radiation (at the expense of inhibition of proliferation and death of immunocompetent cells) can essentially overlap immunostimulating effect related to the changes in antigenic character of tumoral cells

  12. Late response to whole-lung irradiation alone and with whole-body hyperthermia in dogs

    International Nuclear Information System (INIS)

    Gillette, S.M.; Gillette, E.L.; Dawson, C.A.

    1997-01-01

    The late effects of whole-lung irradiation with and without whole-body hyperthermia were studied in beagle dogs. The reference doses ranged from 18 to 49.5 Gy given in 1.5-Gy fractions over 6 weeks. Whole-body hyperthermia was given in three 2-h treatments to a deep rectal temperature of 42.0 degrees C. Radiation was given simultaneously with hyperthermia on those days. Physiological and histopathological responses were evaluated. Physiological changes included decreases in cardiac output, systemic blood pressure, dynamic compliance and serotonin uptake. Early changes included an increase in extravascular water and total protein in the lavage. These changes were considered mild, were compensated for and occurred only in dogs receiving doses of 40.5 Gy or greater given in 1.5-Gy fractions over 6 weeks. Histopathological change were typical of irradiated lung and included pleural fibrosis, interstitial fibrosis, fibrotic foci, and peribronchial and perivascular fibrosis. There was no enhancement of late injury to lung by hyperthermia seen in this study. 17 refs., 3 figs., 2 tabs

  13. Fast temperature optimization of multi-source hyperthermia applicators with reduced-order modeling of 'virtual sources'

    International Nuclear Information System (INIS)

    Cheng, K-S; Stakhursky, Vadim; Craciunescu, Oana I; Stauffer, Paul; Dewhirst, Mark; Das, Shiva K

    2008-01-01

    The goal of this work is to build the foundation for facilitating real-time magnetic resonance image guided patient treatment for heating systems with a large number of physical sources (e.g. antennas). Achieving this goal requires knowledge of how the temperature distribution will be affected by changing each source individually, which requires time expenditure on the order of the square of the number of sources. To reduce computation time, we propose a model reduction approach that combines a smaller number of predefined source configurations (fewer than the number of actual sources) that are most likely to heat tumor. The source configurations consist of magnitude and phase source excitation values for each actual source and may be computed from a CT scan based plan or a simplified generic model of the corresponding patient anatomy. Each pre-calculated source configuration is considered a 'virtual source'. We assume that the actual best source settings can be represented effectively as weighted combinations of the virtual sources. In the context of optimization, each source configuration is treated equivalently to one physical source. This model reduction approach is tested on a patient upper-leg tumor model (with and without temperature-dependent perfusion), heated using a 140 MHz ten-antenna cylindrical mini-annular phased array. Numerical simulations demonstrate that using only a few pre-defined source configurations can achieve temperature distributions that are comparable to those from full optimizations using all physical sources. The method yields close to optimal temperature distributions when using source configurations determined from a simplified model of the tumor, even when tumor position is erroneously assumed to be ∼2.0 cm away from the actual position as often happens in practical clinical application of pre-treatment planning. The method also appears to be robust under conditions of changing, nonlinear, temperature-dependent perfusion. The

  14. Hyperthermia and radiotherapy

    International Nuclear Information System (INIS)

    Lindholm, C.E.

    1992-01-01

    Combined hyperthermia (HT 45 min once or twice per week) and low dose radiotherapy (LDRT 30-34.5 Gy in 2-3 weeks) have been given to 182 locally recurrent or metastatic superficial tumours in 133 patients. Tumour response was analysed in 137 tumours in 100 patients. The overall complete response (CR) was 50% with a median duration (DCR) of 13±3 months. When mammary carcinoma, representing 62% of the treated tumours, were analysed, CR was 62% with a DCR of 14±4 months. In a comparative, non-randomized study, on 34 matched tumour pairs in 24 patients, treatment was given with LDRT+HT to the larger and the same LDRT to the smaller tumour, the patients acting as their own control. A significant difference in CR was obtained in favour of the combined treatment (p=0.0013 all diagnosis and p=0.0027 mammary carcinoma). There was no significant difference in DCR between the two modalities. No significant difference in CR was seen when tumours were randomely treated with HT once (CR 56%) or twice (CR 69%) per week combined with the same LDRT. Predictive factors for CR, multivariately analysed (15 parameters), in mammary carcinoma recurring in earlier irradiated regions, were; the present LDRT absorbed dose (p=0.02) and the average minimum temperature in the best HT session (p=0.03). Significant skin toxicity was seen in 28% of all the 182 heated regions. Prognostic factors for skin damage, multivariately analysed, were; the extension of the heated region (p=0.007) and the highest average maximum temperature in any of the HT sessions (p=0.04). Pain was in some way correlated to severe toxicity but was not considered to be an optimal monitor for HT as many patients with severe and moderate pain were without any serious skin reactions, while slight or no pain sometimes were associated with severe reactions. 401 refs

  15. Hyperthermia: Clinical promise and current challenges

    International Nuclear Information System (INIS)

    Kapp, D.S.

    1987-01-01

    Local-regional hyperthermia (HT) when used in conjunction with radiation therapy (XRT), has been shown in numerous clinical trials to result in considerable improvement in response rates and local tumor control rates when compared with treatment by XRT alone. Although considerable progress has been made in understanding the biological basis for hyperthermia induced cytotoxicity and radiosensitization, additional research remains in establishing the optimal treatment schedules for the clinical utilization of HT-XRT. The number of HT treatments; the sequencing of HT and XRT; the frequency of administration of HT; and the ideal temperature-time parameters all remain to be better defined for the clinical setting. The role of tumor blood flow on the thermal distributions also warrants further investigation. In addition, considerable effort is needed to improve hyperthermia equipment in order to provide more uniform therapeutic temperature distributions (temperatures ≥42.5%C). Better heating equipment is particularly needed for the treatment of deep seeted tumors. Pertinent clinical literature will be presented summarizing the clinical promise of hyperthermia and the above mentioned clinical challenges

  16. Modification of reference temperature program in reactor regulating system

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Sung Sik; Lee, Byung Jin; Kim, Se Chang; Cheong, Jong Sik [Korea Power Engineering Company, Inc., Seoul (Korea, Republic of); Kim, Ji In; Doo, Jin Yong [Korea Electric Power Cooperation, Yonggwang (Korea, Republic of)

    1999-12-31

    In Yonggwang nuclear units 3 and 4 currently under commercial operation, the cold temperature was very close to the technical specification limit of 298 deg C during initial startup testing, which was caused by the higher-than-expected reactor coolant system flow. Accordingly, the reference temperature (Tref) program needed to be revised to allow more flexibility for plant operations. In this study, the method of a specific test performed at Yonggwang nuclear unit 4 to revise the Tref program was described and the test results were discussed. In addition, the modified Tref program was evaluated on its potential impacts on system performance and safety. The methods of changing the Tref program and the associated pressurizer level setpoint program were also explained. Finally, for Ulchin nuclear unit 3 and 4 currently under initial startup testing, the effects of reactor coolant system flow rate on the coolant temperature were evaluated from the thermal hydraulic standpoint and an optimum Tref program was recommended. 6 refs., 4 figs., 2 tabs. (Author)

  17. Modification of reference temperature program in reactor regulating system

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Sung Sik; Lee, Byung Jin; Kim, Se Chang; Cheong, Jong Sik [Korea Power Engineering Company, Inc., Seoul (Korea, Republic of); Kim, Ji In; Doo, Jin Yong [Korea Electric Power Cooperation, Yonggwang (Korea, Republic of)

    1998-12-31

    In Yonggwang nuclear units 3 and 4 currently under commercial operation, the cold temperature was very close to the technical specification limit of 298 deg C during initial startup testing, which was caused by the higher-than-expected reactor coolant system flow. Accordingly, the reference temperature (Tref) program needed to be revised to allow more flexibility for plant operations. In this study, the method of a specific test performed at Yonggwang nuclear unit 4 to revise the Tref program was described and the test results were discussed. In addition, the modified Tref program was evaluated on its potential impacts on system performance and safety. The methods of changing the Tref program and the associated pressurizer level setpoint program were also explained. Finally, for Ulchin nuclear unit 3 and 4 currently under initial startup testing, the effects of reactor coolant system flow rate on the coolant temperature were evaluated from the thermal hydraulic standpoint and an optimum Tref program was recommended. 6 refs., 4 figs., 2 tabs. (Author)

  18. Radiofrequency hyperthermia for advanced malignant liver tumors

    International Nuclear Information System (INIS)

    Nagata, Y.; Okuno, Y.; Mitsumori, M.; Akuta, K.; Nishimura, Y.; Masunaga, S.; Kanamori, S.; Fujishiro, M.; Hiraoka, M.; Takahashi, M.; Abe, M.

    1996-01-01

    Purpose: To evaluate thermometry and the clinical results of radiofrequency (RF) thermotherapy for advanced malignant liver tumors. Materials and Methods One-hundred and seventy-three patients with malignant liver tumors treated between 1983 and 1995 underwent hyperthermia. Surgery were contraindicated in all patients. The 173 tumors consisted of 114 hepatocellular carcinomas(HCCs), and 59 non-HCCs(45 metastatic liver tumors and 12 cholangiocarcinomas). Eight MHz RF capacitive heating equipment was used for hyperthermia. Two opposing 25-cm or 30-cm electrodes were generally used for heating liver tumors. Our standard protocol was to administer hyperthermia 40-50 minutes twice a week to a total of 8 sessions. Temperature of the liver tumor was measured by microthermocouples. In each patient, a single catheter was inserted into the liver tumor through the normal liver. Transcatheter arterial embolization, radiotherapy, immunotherapy, and chemotherapy were combined with hyperthermia depending on the patient's liver function and tumor location. The therapeutic efficacy was evaluated by the change in tumor size assessed by computed tomography (CT) three or four months after the completion of treatment. Results One-hundred and forty (81%) of 173 patients underwent hyperthermia more than 4 times. Thermometry could be performed in 77(55%) of these 140 patients. Neither systolic nor diastolic blood pressure changed significantly after hyperthermia. However, pulse rate significantly increased from 82.8 ± 1.1 to 96.5 ± 1.3 beats/min. Only 21 patients (11%) showed a decrease in pulse rate after hyperthermia. Body temperature increased from 36.3 ±0.1 to 37.4±0.2 after hyperthermia. Sequelae of hyperthermia included focal fat burning in 20 (12%), gastric ulceration in 4 (2%), and liver necrosis in 1(1%). Sequelae of thermometry were severe peritoneal pain in 7 (11%), intraperitoneal hematoma in 1(1%), and pneumothorax in one (1%) patient. The maximal tumor temperature

  19. Morphologic alterations in normal and neoplastic tissues following hyperthermia treatment

    International Nuclear Information System (INIS)

    Badylak, S.F.; Babbs, C.F.

    1984-01-01

    The sequential morphologic alterations in normal skeletal muscle in rats, Walker 256 tumors in rats, and transmissible venereal tumors (TVT) in dogs following microwave-induced hyperthermia (43 0 C and 45 0 for 20 minutes) were studied by light and electron microscopy. Normal muscle and Walker 256 tumors showed vascular damage at 5 minutes post-heating (PH), followed by suppuration and thrombosis at 6 and 48 hours PH, and by regeneration and repair at 7 days PH. Endothelial damage and parenchymal degeneration were present 5 minutes PH. Progressive ischemic injury occurred for at least 48 hours PH. Two hyperthermia treatments, separated by a 30 or 60 minute cooling interval, were applied to rats implanted with Walker 256 tumors. Increased selective heating of tumor tissue versus surrounding normal tissue, and increased intratumoral temperatures were found during the second hyperthermia treatment. Canine TVTs were resistant to hyperthermia damage. These results characterized the sequential morphologic alterations following hyperthermia treatment and showed that: 1) vascular damage contributed to the immediate and latent cytotoxic effects of hyperthermia, 2) selective heating occurred in the neoplastic tissue disrupted by prior heat treatment, and 3) not all neoplasms are responsive to hyperthermia treatment

  20. Feasibility study of local ultrasound hyperthermia in cancer therapy

    International Nuclear Information System (INIS)

    Jones, K.G.; Straube, W.; Emami, B.; Perez, C.A.

    1987-01-01

    This paper describes a retrospective analysis of patients treated at Washington University for recurrent or persistent cancer with Ultrasound Hyperthermia between October 1984 and June 1986. Fifteen of 102 lesions were treated during this time period with Ultrasound Hyperthermia instead of microwave hyperthermia due to the size of the lesion needing heat at depths greater than 4 cm. Also, the patients' lesion could not be implanted for interstitial microwave hyperthermia. Fourteen of the treated patients received concomitant radiotherapy, while one received concomitant Bleomycin. There were 79 total hyperthermia treatments delivered, of which 67 achieved a therapeutic temperature of 43 0 C for 60 minutes. During 15/79 treatments, patients experienced pain; of which 11/15 lead to poor heating. Only one treatment of the twelve poor treatments was secondary to technical difficulties. Complete local control was accomplished in seven patients, a partial response in four patients. The results of therapeutic heating and its relationship to the site of treatment and local control are presented, along with phantom studies of Ultrasound microwave hyperthermia reemphasizing the feasibility of using Ultrasound Hyperthermia

  1. Interstitial microwave hyperthermia treatment investigations

    International Nuclear Information System (INIS)

    Siauve, N; Lormel, C

    2012-01-01

    Microwave ablation also called interstitial hyperthermia is a medical procedure used in the treatment of many cancers, cardiac arrhythmias and other medical conditions. With this medical therapy, an electromagnetic source (antenna) is directly positioned in the target tissue and a sufficient power is injected to necrosis the tissue. The aim of this study is to propose a design procedure and develop the associated tools, for determining the optimal shape, dimensions, type and operating frequency of antenna according to the target volume. In this context, a 3D numerical predictive model of temperature elevation induced by the electric fields and two benches for thermal and electrical tissues properties characterization have been developed. To validate the procedure and the different tools, an experimental bench test which includes interstitial antenna, external microwave generator, phantom that represents the target tissue and measurement system of temperature and electric field has been elaborated.

  2. Recommended reference materials for realization of physicochemical properties pressure-volume-temperature relationships

    CERN Document Server

    Herington, E F G

    1977-01-01

    Recommended Reference Materials for Realization of Physicochemical Properties presents recommendations of reference materials for use in measurements involving physicochemical properties, namely, vapor pressure; liquid-vapor critical temperature and critical pressure; orthobaric volumes of liquid and vapor; pressure-volume-temperature properties of the unsaturated vapor or gas; and pressure-volume-temperature properties of the compressed liquid. This monograph focuses on reference materials for vapor pressures at temperatures up to 770 K, as well as critical temperatures and critical pressures

  3. Hyperthermia: clinical results

    International Nuclear Information System (INIS)

    Bicher, H.I.

    1982-01-01

    A large number of patients have now been entered into a phase I/II protocol to examine the effects of fractionated hyperthermia and radiation on tumor response. Included in the study were 11 different histologies with anatomical locations varying between peripheral and superficial metastases to deep-seated, solid tumors. Patients were treated with four fractions of microwave-induced hyperthermia (45.0 +- 0.5 0 C), each separated by intervals of 72 hours. Microwaves at frequencies of 915 MHz or 300 MHz were employed, Patients were given a one week rest following the first four treatments, following which a second series of four fractions were administered, again at 72 hour intervals. Each of these fractions consisted of a 400 rad dose of radiation followed within 20 min by hyperthermia (42.5 +- 5 0 C) for 1.5 hours. To date 121 fields have been treated by 82 patients. Total regression is seen in 65% of all cases, partial regression in 35% and no response is seen in only 5% of treatments. Adverse effects were rare. Site specific trials are currently in progress to study the feasibility of deep-seated heating with intracavitary antennae as well as to assess tumor response. In addition, a randomized trial to examine the clinical relevance of thermotolerance has been started

  4. Investigation properties of superparamagnetic nanoparticles and magnetic field-dependent hyperthermia therapy

    Science.gov (United States)

    Hedayatnasab, Z.; Abnisa, F.; Daud, W. M. A. Wan

    2018-03-01

    The application of superparamagnetic nanoparticles as heating agents in hyperthermia therapy has made a therapeutic breakthrough in cancer treatment. The high efficiency of this magnetic hyperthermia therapy has derived from a great capability of superparamagnetic nanoparticles to generate focused heat in inaccessible tumors being effectively inactivated. The main challenges of this therapy are the improvement of the induction heating power of superparamagnetic nanoparticles and the control of the hyperthermia temperature in a secure range of 42 °C to 47 °C, at targeted area. The variation of these hyperthermia properties is principally dependent on the magnetic nanoparticles as well as the magnetic field leading to enhance the efficiency of magnetic hyperthermia therapy at targeted area and also avoid undue heating to healthy cells. The present study evaluates the magnetic hyperthermia therapy through the determination of superparamagnetic nanoparticles properties and magnetic field’ parameters.

  5. Combined effects of hyperthermia and radiation in cultured mammalian cells

    International Nuclear Information System (INIS)

    Ben-Hur, E.; Elkind, M.M.; Riklis, E.

    1977-01-01

    Hyperthermia (temperatures of 39 0 C or higher) enhances the killing of mammalian cells by ionizing radiation (fission-spectrum neutrons and x-rays). The nature and the magnitude of the enhanced radiation killing varies with temperature and for a fixed temperature during irradiation, the enhanced lethality varies inversely with dose rate. For temperatures up to 41 0 C, dose fractionation measurements indicate that hyperthermia inhibits the repair of sublethal damage. At higher temperatures, the expression of potentially lethal damage is enhanced. Since the effect of heat is greatest in cells irradiated during DNA synthesis, the radiation age-response pattern is flattened by hyperthermia. In addition to the enhanced cell killing described above, three other features of the effect of hyperthermia are important in connection with the radiation treatment of cancer. The first is that heat selectively sensitizes S-phase cells to radiation. The second is that it takes radiation survivors 10 to 20 hrs after a modest heat treatment to recover their ability to repair sublethal damage. And the third is that hyperthermia reduces the magnitude of the oxygen enhancement ratio. Thus, heat if applied selectively, could significantly increase the margin of damage between tumors and normal tissues

  6. FDTD analysis of a noninvasive hyperthermia system for brain tumors.

    Science.gov (United States)

    Yacoob, Sulafa M; Hassan, Noha S

    2012-08-14

    Hyperthermia is considered one of the new therapeutic modalities for cancer treatment and is based on the difference in thermal sensitivity between healthy tissues and tumors. During hyperthermia treatment, the temperature of the tumor is raised to 40-45°C for a definite period resulting in the destruction of cancer cells. This paper investigates design, modeling and simulation of a new non-invasive hyperthermia applicator system capable of effectively heating deep seated as well as superficial brain tumors using inexpensive, simple, and easy to fabricate components without harming surrounding healthy brain tissues. The proposed hyperthermia applicator system is composed of an air filled partial half ellipsoidal chamber, a patch antenna, and a head model with an embedded tumor at an arbitrary location. The irradiating antenna is placed at one of the foci of the hyperthermia chamber while the center of the brain tumor is placed at the other focus. The finite difference time domain (FDTD) method is used to compute both the SAR patterns and the temperature distribution in three different head models due to two different patch antennas at a frequency of 915 MHz. The obtained results suggest that by using the proposed noninvasive hyperthermia system it is feasible to achieve sufficient and focused energy deposition and temperature rise to therapeutic values in deep seated as well as superficial brain tumors without harming surrounding healthy tissue. The proposed noninvasive hyperthermia system proved suitable for raising the temperature in tumors embedded in the brain to therapeutic values by carefully selecting the systems components. The operator of the system only needs to place the center of the brain tumor at a pre-specified location and excite the antenna at a single frequency of 915 MHz. Our study may provide a basis for a clinical applicator prototype capable of heating brain tumors.

  7. FDTD analysis of a noninvasive hyperthermia system for brain tumors

    Directory of Open Access Journals (Sweden)

    Yacoob Sulafa M

    2012-08-01

    Full Text Available Abstract Background Hyperthermia is considered one of the new therapeutic modalities for cancer treatment and is based on the difference in thermal sensitivity between healthy tissues and tumors. During hyperthermia treatment, the temperature of the tumor is raised to 40–45°C for a definite period resulting in the destruction of cancer cells. This paper investigates design, modeling and simulation of a new non-invasive hyperthermia applicator system capable of effectively heating deep seated as well as superficial brain tumors using inexpensive, simple, and easy to fabricate components without harming surrounding healthy brain tissues. Methods The proposed hyperthermia applicator system is composed of an air filled partial half ellipsoidal chamber, a patch antenna, and a head model with an embedded tumor at an arbitrary location. The irradiating antenna is placed at one of the foci of the hyperthermia chamber while the center of the brain tumor is placed at the other focus. The finite difference time domain (FDTD method is used to compute both the SAR patterns and the temperature distribution in three different head models due to two different patch antennas at a frequency of 915 MHz. Results The obtained results suggest that by using the proposed noninvasive hyperthermia system it is feasible to achieve sufficient and focused energy deposition and temperature rise to therapeutic values in deep seated as well as superficial brain tumors without harming surrounding healthy tissue. Conclusions The proposed noninvasive hyperthermia system proved suitable for raising the temperature in tumors embedded in the brain to therapeutic values by carefully selecting the systems components. The operator of the system only needs to place the center of the brain tumor at a pre-specified location and excite the antenna at a single frequency of 915 MHz. Our study may provide a basis for a clinical applicator prototype capable of heating brain tumors.

  8. Hyperthermia, a modality in the wings

    Directory of Open Access Journals (Sweden)

    Szasz A

    2007-01-01

    Full Text Available Hyperthermia is a heat-treatment. It is widely used in various medical fields and has a well-recognized effect in oncology. Its effect is achieved by overheating of the targeted tissues. It is an ancient treatment and a promising physical approach with lack of acceptance by the serious medical use. To accept the method we need strong proofs and stable, reproducible treatment quality, but we are limited by biological, physical/technical and physiological problems. However, the main point - I believe - is the incorrect characterization and unrealistic expectations from this capable method. The temperature concept of the quality assurance guidelines has to be replaced by the heat-dose sensitive characterization, pointing the essence of the hyperthermia method.

  9. On the Reference State for Exergy when Ambient Temperature Fluctuates

    OpenAIRE

    Michel Pons

    2009-01-01

    Exergy (availability) is the amount of mechanical work that could be produced by reversible processes. This notion is revisited in the case when ambient temperature fluctuates. Simple examples are first considered, and then a theoretical approach is developed. It results that the most reliable way for combining entropy and total energy into an exergy function is a linear combination where entropy is multiplied by a constant temperature. It results that ambient air has non-zero exergy, but tha...

  10. The role of hyperthermia in the water economy of desert birds

    NARCIS (Netherlands)

    Tieleman, B.I.; Williams, J.B.

    1999-01-01

    A number of authors have suggested that hyperthermia, the elevation of body temperature (T-b) 2 degrees-4 degrees C above normal, contributes to a reduction in total evaporative water loss (TEWL) in birds. Information about the role of hyperthermia in the water economy of birds is scattered

  11. Hyperthermia-induced degradation of BRCA2 : from bedside to bench and back again

    NARCIS (Netherlands)

    N. van den Tempel (Nathalie)

    2017-01-01

    markdownabstractLocal hyperthermia, a method during which the temperature of a tumor is elevated, clinically increases the efficacy of radiotherapy and chemotherapy, without increasing side-effects. One of the reasons that explains why hyperthermia increases effectivity of these therapies is that it

  12. Clinical thermometry, using the 27 MHz multi-electrode current-source interstitial hyperthermia system in brain tumours.

    NARCIS (Netherlands)

    Kaatee, R.S.; Nowak, P.C.; Zee, J. van der; Bree, J. de; Kanis, B.P.; Crezee, H.; Levendag, P.C.; Visser, A.G.

    2001-01-01

    BACKGROUND AND PURPOSE: In interstitial hyperthermia, temperature measurements are mainly performed inside heating applicators, and therefore, give the maximum temperatures of a rather heterogeneous temperature distribution. The problem of how to estimate lesion temperatures using the

  13. Film bulk acoustic resonator pressure sensor with self temperature reference

    International Nuclear Information System (INIS)

    He, X L; Jin, P C; Zhou, J; Wang, W B; Dong, S R; Luo, J K; Garcia-Gancedo, L; Flewitt, A J; Milne, W I

    2012-01-01

    A novel film bulk acoustic resonator (FBAR) with two resonant frequencies which have opposite reactions to temperature changes has been designed. The two resonant modes respond differently to changes in temperature and pressure, with the frequency shift being linearly correlated with temperature and pressure changes. By utilizing the FBAR's sealed back trench as a cavity, an on-chip single FBAR sensor suitable for measuring pressure and temperature simultaneously is proposed and demonstrated. The experimental results show that the pressure coefficient of frequency for the lower frequency peak of the FBAR sensors is approximately −17.4 ppm kPa −1 , while that for the second peak is approximately −6.1 ppm kPa −1 , both of them being much more sensitive than other existing pressure sensors. This dual mode on-chip pressure sensor is simple in structure and operation, can be fabricated at very low cost, and yet requires no specific package, therefore has great potential for applications. (paper)

  14. Stress-induced hyperthermia in translational stress research

    NARCIS (Netherlands)

    Vinkers, C.H.; Penning, R.; Ebbens, M.M.; Helhammer, J.; Verster, J.C.; Kalkman, C.J.; Olivier, B.

    2010-01-01

    The stress-induced hyperthermia (SIH) response is the transient change in body temperature in response to acute stress. This body temperature response is part of the autonomic stress response which also results in tachycardia and an increased blood pressure. So far, a SIH response has been found in

  15. Effects of Radiofrequency Induced local Hyperthermia on Normal Canine Liver

    International Nuclear Information System (INIS)

    Suh, Chang Ok; Loh, John J. K.; Seong, Jin Sil

    1991-01-01

    In order to assess the effects of radiofrequency-induced local hyperthermia on the normal liver, histopathologic findings and biochemical changes after localized hyperthermia in canine liver were studied. Hyperthermia was externally administered using the Thermotron RF-8 (Yamamoto Vinyter Co., Japan; Capacitive type heating machine) with parallel opposed electrodes. Thirteen dogs were used and allocated into one control group (N=3) and two treatment groups according to the treatment temperature. Group I (N=5) was heated with 42.5±0.5.deg.C for 30 minutes, and Group(N=5) was heated with 45±0.5.deg.C for 15-30 minutes. Samples of liver tissue were obtained through a needle biopsy immediately after hyperthermia and 7, 14 and 28 days after treatment and examined for SGOT, SGPT and alkaline phosphatase. Although SGOT and SGPT were elevated after hyperthermia in both groups (three of five in each group), there was no liver cell necrosis or hyperthermia related mortality in Group I. A hydropic swelling of hepatocytes was prominent histologic finding. Hyperthermia with 45.deg.C for 30 minutes was fatal and showed extensive liver cell necrosis. In conclusion, liver damage day heat of 42.5±0.5.deg.C for 30 minutes is reversible, and liver damage by heat of 45±0.5.deg.C for 30 minutes can be fatal or irreversible. However, these results cannot be applied directly to human trial. Therefore, in order to apply hyperthermic treatment on human liver tumor safely, close observation of temperature with proper thermometry is mandatory. Hyperthermic treatment should be confined to the tumor area while sparing a normal liver as much as possible

  16. Interaction of hyperthermia and radiation: radiation quality

    International Nuclear Information System (INIS)

    Loshek, D.D.; Orr, J.S.; Solomonidis, E.

    1981-01-01

    Cell-survival data were collected to determine the survival response of asynchronous CHO cells subject to radiation and hyperthermia. The irradiation was at room temperature 100 minutes before exposure to hyperthermia at 42 0 C. The survival response to the combination of these two agents is expressed by means of a survival surface, a three-dimensional concept relating cell survival to heat dose and radiation dose. The survival surface could be approximately described by a survival model comprising three components of cell killing: the unperturbed radiation component, the unperturbed hyperthermia component and the interaction component. The dependence of the radiation component and the interaction component on radiation quality were investigated by irradiating with either 60 Co γ rays, 250 kV X rays or 14.7 MeV neutrons. An analysis suggests that the interaction component and the radiation component exhibit similar dependencies on radiation quality both for the deposition of damage and the repair or accumulation of that damage. (U.K.)

  17. Hyperthermia and hyperglycemia in oncology

    International Nuclear Information System (INIS)

    Zhavrid, Eh.A.; Osinskij, S.P.; Fradkin, S.Z.

    1987-01-01

    Consideration is being given to publication data and results of author's investigations into the effect of hyperthermia and hyperglycemia on physico-chemical characteristics and growth of various experimental tumors. Factors, modifying thermosensitivity, mechanisms of hyperthermia effect, various aspects of thermochimio- and thermoradiotherapy have been analyzed. Effect of artificial hyperglycemia on metabolism and kinetics of tumor and some normal cells is considered in detail. Many data, testifying to sufficient growth of efficiency of oncologic patient treatment under conditions of multimodality therapy including hyperthermia and hyperglycemia are presented

  18. Social factors modulate restraint stress induced hyperthermia in mice.

    Science.gov (United States)

    Watanabe, Shigeru

    2015-10-22

    Stress-induced hyperthermia (SIH) was examined in three different social conditions in mice by thermographic measurement of the body surface temperature. Placing animals in cylindrical holders induced restraint stress. I examined the effect of the social factors in SIH using the thermograph (body surface temperature). Mice restrained in the holders alone showed SIH. Mice restrained in the holders at the same time as other similarly restrained cage mates (social equality condition) showed less hyperthermia. Interestingly, restrained mice with free moving cage mates (social inequality condition) showed the highest hyperthermia. These results are consistent with a previous experiment measuring the memory-enhancing effects of stress and the stress-induced elevation of corticosterone, and suggest that social inequality enhances stress. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Present clinical status of hyperthermia associated with radiotherapy

    International Nuclear Information System (INIS)

    Jaulerry, C.; Bataini, J.P.; Brunin, F.; Gaboriaud, G.

    1981-01-01

    Improved techniques for inducing heat: ultrasound, microwaves, diathermy with different application modalities, capable of producing localized superficial or deep, regional or total body hyperthermia have been responsible for the multiplication of clinical trials. These studies have confirmed the tumoricidal effect of hyperthermia alone, or more especially when combined with radiotherapy, and the good tolerance of normal tissues to localized temperatures of 42 to 43.5 0 C even in previously irradiated cases. Localized heating does not seem to increase the incidence of metastasis. Enhancement ratios and therapeutic gain with respect to normal tissues are not yet well documented. Many problems, including the heterogenicity of tissues to be heated, difficulties with temperature monitoring, and selection of appropriate sequential scheduling of radiation and hyperthermia remain unsolved and further investigationss are required [fr

  20. Reference mean temperature for evaluation of performance of thermal diffusion column for isotope separation

    International Nuclear Information System (INIS)

    Yamamoto, Ichiro; Kanagawa, Akira

    1987-01-01

    In order to evaluate separative performance of a thermal diffusion column, a simplification is usually made in which the temperature dependence of the relevant properties such as thermal diffusion constant is ignored and some proper mean values evaluated at a specific ''mean'' temperature are used. Adoption of weighted average of temperature distribution is common for the ''mean'' temperature, but there exists no definite way of determining mean temperature. The present paper proposes a new reference mean temperature determined by the equation governing the free convection. It is based on the fact that the multiplication effect of free convection is essential to separation by thermal diffusion column. The reference mean temperature is related to pressure difference between top and bottom of column and is higher than a mass-averaged temperature (due to gravitational force) by a contribution of viscous force. The reference mean temperature was calculated, as a reference, for an Ar isotope separating column with an inner hot radius of 0.2 mm and an outer cold radius of 5 mm. The results confirmed the validity of an approximate formula expressing effects of temperature difference and ratio of inner and outer radii of column explicitly for the temperature. The reference mean temperature calculated from pressure difference given by axisymmetric solution of equations of change was in good agreement with the analytical solution. (author)

  1. Magnetic nanowires and hyperthermia: How geometry and material affect heat production efficiency

    KAUST Repository

    Contreras, Maria F.; Zaher, A.; Perez, Jose E.; Ravasi, Timothy; Kosel, Jü rgen

    2015-01-01

    Magnetic hyperthermia, which refers to the production of heat by magnetic nanostructures under an alternating magnetic field (AMF), has been previously investigated with superparamagnetic nanobeads as a cancer therapy method. Magnetic nanowires (NWs

  2. An FDTD code for hyperthermia treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Marrocco, G.; Bardati, F. [Rome Univ. Tor Vergata (Italy). Dipt. di Informatica, sistemi e produzione; Tognolatti, P. [L' Aquila Univ. (Italy). Dipt. di Ingegneria Elettrica

    1999-08-01

    Radio-frequency hyperthermia is an anticancer modality based on the heating of tumours by radiating sources. A set of antennas is frequently used to enhance power depositions in tissues. Treatments planning needs electromagnetic field computation within realistic body models. Since several simulation may be required the optimize the antenna-body configuration, the electromagnetic solver should be designed in such a way that new configuration of the antenna set-up can be solved without heavy changes of the basic numerical code. In this paper a numerical investigation on the effects of a segmentation technique will be presented, with reference to an FDTD computation and the heating of a paediatric tumour.

  3. Hyperthermia and chemotherapy agent

    International Nuclear Information System (INIS)

    Roizin-Towle, L.; Hall, E.J.

    1981-01-01

    The use of chemotherapeutic agents for the treatment of cancer dates back to the late 19th century, but the modern era of chemotherapy drugs was ushered in during the 1940's with the development of the polyfunctional alkylating agent. Since then, numerous classes of drugs have evolved and the combined use of antineoplastic agents with other treatment modalities such as radiation or heat, remains a large relatively unexplored area. This approach, combining local hyperthermia with chemotherapy agents affords a measure of targeting and selective toxicity not previously available for drugs. In this paper, the effects of adriamycin, bleomycin and cis-platinum are examined. The adjuvant use of heat may also reverse the resistance of hypoxic cells noted for some chemotherapy agents

  4. Hyperthermia and fatigue

    DEFF Research Database (Denmark)

    Nybo, Lars

    2008-01-01

    The present review addresses mechanisms of importance for hyperthermia-induced fatigue during short intense activities and prolonged exercise in the heat. Inferior performance during physical activities with intensities that elicit maximal oxygen uptake is to a large extent related to perturbation...... of the cardiovascular function, which eventually reduces arterial oxygen delivery to the exercising muscles. Accordingly, aerobic energy turnover is impaired and anaerobic metabolism provokes peripheral fatigue. In contrast, metabolic disturbances of muscle homeostasis are less important during prolonged exercise...... in the heat, because increased oxygen extraction compensates for the reduction in systemic blood flow. The decrease in endurance seems to involve changes in the function of the central nervous system (CNS) that lead to fatigue. The CNS fatigue appears to be influenced by neurotransmitter activity...

  5. Clinical hyperthermia of prostate cancer using magnetic nanoparticles - preliminary experience with a new interstitial technique

    International Nuclear Information System (INIS)

    Johannsen, M.; Gneveckow, U.; Eckelt, L.; Feussner, A.; Waldoefner, N.; Scholz, R.; Deger, S.; Wust, P.; Loening, S.A.; Jordan, A.

    2005-01-01

    Full text: Thermotherapy using biocompatible superparamagnetic nanoparticles, also referred to as magnetic fluid hyperthermia (MFH), has been shown to inhibit prostate cancer growth in the Dunning rat model. Here we present the first clinical application of interstitial hyperthermia using magnetic nanoparticles in locally recurrent prostate cancer. Treatment planning was carried out using computerized tomography (CT) of the prostate. Based on the individual anatomy of the prostate and the estimated specific absorption rate (SAR) of magnetic fluids in prostatic tissue, the number and position of magnetic fluid depots required for sufficient heat deposition was calculated using the AMIRA software and a newly developed prostate module. Nanoparticle suspensions (MagForce MFL AS, MagForce Nanotechnologies GmbH, Berlin, Germany) were injected transperineally into the prostate under transrectal ultrasound and flouroscopy guidance. Treatments were delivered in the first magnetic field applicator for use in humans (MFH300F, MagForce Nanotechnologies GmbH, Berlin), using an alternating magnetic field with a frequency of 100 kHz and variable field strength (0-18 kA/m). Invasive thermometry of the prostate was carried out in the first and last of 6 weekly hyperthermia sessions of 60 min duration. CT-scans of the prostate were repeated following the first and last hyperthermia treatment to document magnetic nanoparticle distribution and the position of the thermometry probes in the prostate. Nanoparticles were retained in the prostate during the treatment interval of 6 weeks, as documented by CT. Treatment was well tolerated. During the first treatment, maximum intra-prostatic temperatures measured by 4 thermometry probes at a magnetic field strength of 4.0-5.0 kA/m were 48.5, 43.0, 43.7 and 43.6 o C, whereas minimal temperatures were 41.2, 40.3, 40.0 and 41.1 o C, respectively. During the sixth and last treatment of the same patient, maximum intraprostatic temperatures were 42

  6. Kernel reconstruction methods for Doppler broadening — Temperature interpolation by linear combination of reference cross sections at optimally chosen temperatures

    International Nuclear Information System (INIS)

    Ducru, Pablo; Josey, Colin; Dibert, Karia; Sobes, Vladimir; Forget, Benoit; Smith, Kord

    2017-01-01

    This paper establishes a new family of methods to perform temperature interpolation of nuclear interactions cross sections, reaction rates, or cross sections times the energy. One of these quantities at temperature T is approximated as a linear combination of quantities at reference temperatures (T_j). The problem is formalized in a cross section independent fashion by considering the kernels of the different operators that convert cross section related quantities from a temperature T_0 to a higher temperature T — namely the Doppler broadening operation. Doppler broadening interpolation of nuclear cross sections is thus here performed by reconstructing the kernel of the operation at a given temperature T by means of linear combination of kernels at reference temperatures (T_j). The choice of the L_2 metric yields optimal linear interpolation coefficients in the form of the solutions of a linear algebraic system inversion. The optimization of the choice of reference temperatures (T_j) is then undertaken so as to best reconstruct, in the L∞ sense, the kernels over a given temperature range [T_m_i_n,T_m_a_x]. The performance of these kernel reconstruction methods is then assessed in light of previous temperature interpolation methods by testing them upon isotope "2"3"8U. Temperature-optimized free Doppler kernel reconstruction significantly outperforms all previous interpolation-based methods, achieving 0.1% relative error on temperature interpolation of "2"3"8U total cross section over the temperature range [300 K,3000 K] with only 9 reference temperatures.

  7. Magnetic Properties of Magnetic Nanoparticles for Efficient Hyperthermia

    Directory of Open Access Journals (Sweden)

    Ihab M. Obaidat

    2015-01-01

    Full Text Available Localized magnetic hyperthermia using magnetic nanoparticles (MNPs under the application of small magnetic fields is a promising tool for treating small or deep-seated tumors. For this method to be applicable, the amount of MNPs used should be minimized. Hence, it is essential to enhance the power dissipation or heating efficiency of MNPs. Several factors influence the heating efficiency of MNPs, such as the amplitude and frequency of the applied magnetic field and the structural and magnetic properties of MNPs. We discuss some of the physics principles for effective heating of MNPs focusing on the role of surface anisotropy, interface exchange anisotropy and dipolar interactions. Basic magnetic properties of MNPs such as their superparamagnetic behavior, are briefly reviewed. The influence of temperature on anisotropy and magnetization of MNPs is discussed. Recent development in self-regulated hyperthermia is briefly discussed. Some physical and practical limitations of using MNPs in magnetic hyperthermia are also briefly discussed.

  8. Early experience in the combination of regional hyperthermia and radiotherapy

    International Nuclear Information System (INIS)

    Howard, G.C.W.; Bleehen, N.M.

    1987-01-01

    An annular array of radiative radiofrequency applicators (APA) has been developed by the BSD Corporation, Salt Lake City (USA) which has been shown to be capable of deep heating. The BSD 1000 clinical hyperthermia system has been installed at Cambridge for 18 months and a pilot study has been performed to assess the feasibility of pelvic regional hyperthermia in the treatment of extensive pelvic malignancy. The study confirms published data that the APA is capable of heating at depth within the pelvis. Therapeutic temperatures may be reached in the majority of treatments but are difficult to maintain due to acute toxicity. Steering of the area of maximal energy deposition may improve treatments considerably. A randomised trial is now being designed to assess whether the synergism between radiation and hyperthermia seen in superficial lesions can be demonstrated in tumours occurring in the pelvis. (orig./MG)

  9. Interaction of the effects of hyperthermia and ionizing radiation on cell survival

    International Nuclear Information System (INIS)

    Loshek, D.D.

    1976-09-01

    The literature concerning the effects of hyperthermia and radiation on cellular reproductive integrity is reviewed. The cell line and the physical and biological aspects of the experiments are described. Preliminary experiments revealed that the experimental stability was adequate for inter-experiment comparisons, provided that sufficient control data were obtained. Further experiments provided a cursory examination of several aspects of the interaction between radiation and hyperthermia. A simple sensitization model that would account for the observed results for any single value of the perturbing radiation or hyperthermia dose was developed. Using the concept of the survival surface, this simple model was expanded to describe simultaneously survivals for any combination of the radiation and hyperthermia dose. The interaction component of this model is first order in both hyperthermia exposure and radiation dose. The mechanism by which radiation contributes to the interaction was investigated by altering the radiation quality. The results suggest that high LET events contribute to the interaction. The mechanism by which hyperthermia contributes to the interaction was investigated by altering the hyperthermia temperature. A thermodynamic analysis of the data reveals parallels with the effects of hyperthermia and radiation on protein, suggesting a possible involvement of protein denaturation in cell inactivation. (author)

  10. Delineation of potential hot spots for hyperthermia treatment planning optimisation

    NARCIS (Netherlands)

    Wiersma, J.; van Wieringen, N.; Crezee, H.; van Dijk, J. D. P.

    2007-01-01

    The optimal feed parameters of the generators for a complex-phased hyperthermia array system consisting of 4, 8 or even more applicators cannot be found using only the expertise of the treatment staff or using the limited amount of field and temperature data obtained during treatment. A number of

  11. Whole body hyperthermia, but not skin hyperthermia, accelerates brain and locomotor limb circulatory strain and impairs exercise capacity in humans

    DEFF Research Database (Denmark)

    Trangmar, Steven J; Chiesa, Scott T; Kalsi, Kameljit K

    2017-01-01

    Cardiovascular strain and hyperthermia are thought to be important factors limiting exercise capacity in heat-stressed humans, however, the contribution of elevations in skin (Tsk) versus whole body temperatures on exercise capacity has not been characterized. To ascertain their relationships...... was associated with a plateau in MCA and two-legged vascular conductance (VC). Mechanistically, the falling MCA VC was coupled to reductions in PaCO2, whereas the plateau in leg vascular conductance was related to markedly elevated plasma [NA] and a plateau in plasma ATP These findings reveal that whole-body...... hyperthermia, but not skin hyperthermia, compromises exercise capacity in heat-stressed humans through the early attenuation of brain and active muscle blood flow....

  12. Enhancement of immunological activity after mild hyperthermia

    International Nuclear Information System (INIS)

    Noguchi, Kenichi; Hasegawa, Takeo; Takahashi, Tohru

    2002-01-01

    At present, hyperthermia is clinically very important as interdisciplinary therapeutic method, and studies are being performed on combined effects with surgical treatment, radiotherapy, chemotherapy and gene therapy for the treatment of malignant tumors. We evaluated the effects of hyperthermia under temperature of 42.5C and demonstrated that the activation of immunological response is increased and anti-tumor effect cabn be obtained in this studies. We used animals were C3H mice (male,7W) bearing SCC-VII tumor on femur skin. Then, the mice were divided to 10 mice in each group, and only femur region was immersed in warm water for thermal treatment. Also we measured the tumor growth, changes of blood cell fraction and NK cell activity. The results of the present study confirmed: (1) Anti-tumor effect can be given by thermal treatment at relatively mild temperature (mild temperature at 39C-42C); (2) The increase of neutrophils is dependent on the quantity of heat added; (3) Immunological response of monocytes and lymphocytes is associated with it; (4) Activity of the immunological potency as a whole such as activation of NK cells was also confirmed

  13. A thermocouple thermometry system for ultrasound hyperthermia

    International Nuclear Information System (INIS)

    Ozarka, M.; Gharakhani, A.; Magin, R.; Cain, C.

    1984-01-01

    A thermometry system designed to be used in the treatment of cancer by ultrasound hyperthermia is described. The system monitors tumor temperatures using 16 type T (copper-constantan) thermocouples and is controlled by a 12 MHz Intel 8031 microcomputer. An analog circuit board contains the thermocouple amplifiers, an analog multiplexer, scaling circuitry, and an analog to digital converter. A digital board contains the Intel 8031, program memory, data memory, as well as circuitry for control and data communications. Communication with the hyperthermia system control computer is serially by RS-232 with selectable baud rate. Since the thermocouple amplifiers may have slight differences in gain and offset, a calibrated offset is added to a lookup table value to obtain the proper display temperature to within +- 0.1 0 C. The calibration routine, implemented in software, loads a nonvolatile random access memory chip with the proper offset values based on the outputs of each thermocouple channel at known temperatures which bracket a range of interest

  14. Influences of temperature on Arachis hypogaea L. : with special reference to its pollen viability

    NARCIS (Netherlands)

    Beer, de J.F.

    1963-01-01

    The influence was investigated of temperature on growth and development of groundnut, cv. Schwarz 21, Mallorca and Ukraine. Except where stated, all conclusions refer to Schwarz 21. Seed germination was not seriously influenced between 24° and 33°C, although the higher temperatures favoured

  15. Modification of radiation damage in CHO cells by hyperthermia at 40 and 450C

    International Nuclear Information System (INIS)

    Henle, K.J.; Leeper, D.B.

    1977-01-01

    Low hyperthermia at 40 0 C either before or after X irradiation did not alter the slope of the radiation dose-cell survival curve but reduced the D/sub q/ from 145 to 41 or to 0 rad for a pre- or postirradiation incubation period of 2 hr at 40 0 C, respectively. In contrast, hyperthermia at 45 0 C increased the slope of the radiation survival curve by a factor of 1.7 for a radiation pretreatment of 10 min at 45 0 C, but only by 1.3 for the same treatment immediately after irradiation. The corresponding D/sub q/'s were 262 and 138 rad, respectively. A combination of 45 and 40 0 C hyperthermia (10 min at 45 0 C + 2 hr at 40 0 C + X) resulted in a superposition of the individual effects of 45 or 40 0 C hyperthermia on the radiation survival curve. In addition, the radiation survival curve was shifted downward by a factor of three due to the potentiation of 45 0 C hyperthermia damage by postincubation at 40 0 C. Repair of sublethal radiation damage was completely suppressed during incubation at 40 following hyperthermia at 45 0 C. However, when cells were returned to 37 0 C, even after 6 hr at 40 following 45 0 C hyperthermia, the capacity to accumulate and repair sublethal radiation damage was immediately restored. These findings imply that the hyperthermia damage from low or high temperatures interacts differentially with radiation damage. Low hyperthermia at 40 0 C may affect principally the radiation repair system, whereas 45 0 C hyperthermia probably alters the radiation target more severely than the repair system

  16. Clinically Relevant Pharmacological Strategies That Reverse MDMA-Induced Brain Hyperthermia Potentiated by Social Interaction.

    Science.gov (United States)

    Kiyatkin, Eugene A; Ren, Suelynn; Wakabayashi, Ken T; Baumann, Michael H; Shaham, Yavin

    2016-01-01

    MDMA-induced hyperthermia is highly variable, unpredictable, and greatly potentiated by the social and environmental conditions of recreational drug use. Current strategies to treat pathological MDMA-induced hyperthermia in humans are palliative and marginally effective, and there are no specific pharmacological treatments to counteract this potentially life-threatening condition. Here, we tested the efficacy of mixed adrenoceptor blockers carvedilol and labetalol, and the atypical antipsychotic clozapine, in reversing MDMA-induced brain and body hyperthermia. We injected rats with a moderate non-toxic dose of MDMA (9 mg/kg) during social interaction, and we administered potential treatment drugs after the development of robust hyperthermia (>2.5 °C), thus mimicking the clinical situation of acute MDMA intoxication. Brain temperature was our primary focus, but we also simultaneously recorded temperatures from the deep temporal muscle and skin, allowing us to determine the basic physiological mechanisms of the treatment drug action. Carvedilol was modestly effective in attenuating MDMA-induced hyperthermia by moderately inhibiting skin vasoconstriction, and labetalol was ineffective. In contrast, clozapine induced a marked and immediate reversal of MDMA-induced hyperthermia via inhibition of brain metabolic activation and blockade of skin vasoconstriction. Our findings suggest that clozapine, and related centrally acting drugs, might be highly effective for reversing MDMA-induced brain and body hyperthermia in emergency clinical situations, with possible life-saving results.

  17. Gender differences in hyperthermia and regional 5-HT and 5-HIAA depletion in the brain following MDMA administration in rats

    NARCIS (Netherlands)

    Wallinga, Alinde E.; Grahlmann, Carolin; Granneman, Ramon A.; Koolhaas, Jaap M.; Buwalda, Bauke

    2011-01-01

    In the present research the role of gender in MDMA-induced hyperthermia and serotonin depletion is studied by injecting male and female male rats with MDMA or saline 3 times (i.p.) with 3 h interval at dosages of 0.3, 1, 3 or 9 mg/kg at an ambient temperature of 25 degrees C. The acute hyperthermia

  18. Growth hormone deficiency and hyperthermia during exercise

    DEFF Research Database (Denmark)

    Juul, A; Hjortskov, N; Jepsen, Leif

    1995-01-01

    -deficiency may be at risk for developing hyperthermia. To pursue this, we performed a controlled study on sweating and body temperature regulation during exercise in the heat in 16 GH-treated GH-deficient patients with normalized insulin-like growth factor-I and insulin-like growth factor/binding protein-3 serum.......001]. Consequently, the core temperatures of the patients increased significantly after exercise compared with those of the CTs [38.3 C (0.10 C) (MPD) and 38.1 C (0.06 C) (isolated GH deficiency) vs. 37.5 C (0.2 C) (CTs) (P temperature increased significantly during exercise in the patients...... but remained unaltered in the CTs. Sweat secretion rates, as determined by the pilocarpine method, were significantly lower in the MPD patients [77 (SE +/- 10) mg/30 min] than in the CTs [115 (SE +/- 7) mg/30 min] (P

  19. Thermosensitive Nanostructured Media for imaging and Hyperthermia Cancer Treatment

    Science.gov (United States)

    Martirosyan, Karen

    2011-03-01

    Hyperthermia has been used for many years to treat a wide variety of tumors in patients. The most commonly applied method of hyperthermia is capacitive heating by using microwave. Magnetic fluids based on iron oxide (Fe3O4), stabilized by biocompatible surfactants are typically used as heating agent. However, significant limitations of using commercial available magnetic particles are non-selectivity and overheating of surrounding normal tissues. To improve the efficacy of hyperthermia treatment we intend to develop Curie temperature (Tc)-tuned nanostructured media having T2 relaxation response on MRI for selective and self-controlled hyperthermia cancer treatment. As an active part of this media we fabricated superparamagnetic, biocompatible and dextran coated ferrite nanoparticles Mg1+xTixFe2(1-x)O4 at 0.3 x connected to a hydrocarbon chain, such as glycine, hydrazine, or urea. Our experiments revealed that ferrite with formula Mg1.35Ti0.35Fe1.3O4 appears with Curie temperature within 46-50rC. NSF, grant # 0933140.

  20. Quantifying the Combined Effect of Radiation Therapy and Hyperthermia in Terms of Equivalent Dose Distributions

    International Nuclear Information System (INIS)

    Kok, H. Petra; Crezee, Johannes; Franken, Nicolaas A.P.; Stalpers, Lukas J.A.; Barendsen, Gerrit W.; Bel, Arjan

    2014-01-01

    Purpose: To develop a method to quantify the therapeutic effect of radiosensitization by hyperthermia; to this end, a numerical method was proposed to convert radiation therapy dose distributions with hyperthermia to equivalent dose distributions without hyperthermia. Methods and Materials: Clinical intensity modulated radiation therapy plans were created for 15 prostate cancer cases. To simulate a clinically relevant heterogeneous temperature distribution, hyperthermia treatment planning was performed for heating with the AMC-8 system. The temperature-dependent parameters α (Gy −1 ) and β (Gy −2 ) of the linear–quadratic model for prostate cancer were estimated from the literature. No thermal enhancement was assumed for normal tissue. The intensity modulated radiation therapy plans and temperature distributions were exported to our in-house-developed radiation therapy treatment planning system, APlan, and equivalent dose distributions without hyperthermia were calculated voxel by voxel using the linear–quadratic model. Results: The planned average tumor temperatures T90, T50, and T10 in the planning target volume were 40.5°C, 41.6°C, and 42.4°C, respectively. The planned minimum, mean, and maximum radiation therapy doses were 62.9 Gy, 76.0 Gy, and 81.0 Gy, respectively. Adding hyperthermia yielded an equivalent dose distribution with an extended 95% isodose level. The equivalent minimum, mean, and maximum doses reflecting the radiosensitization by hyperthermia were 70.3 Gy, 86.3 Gy, and 93.6 Gy, respectively, for a linear increase of α with temperature. This can be considered similar to a dose escalation with a substantial increase in tumor control probability for high-risk prostate carcinoma. Conclusion: A model to quantify the effect of combined radiation therapy and hyperthermia in terms of equivalent dose distributions was presented. This model is particularly instructive to estimate the potential effects of interaction from different treatment

  1. Simultaneous determination of reference free-stream temperature and convective heat transfer coefficients

    International Nuclear Information System (INIS)

    Jeong, Gi Ho; Song, Ki Bum; Kim, Kui Soon

    2001-01-01

    This paper deals with the development of a new method that can obtain heat transfer coefficient and reference free stream temperature simultaneously. The method is based on transient heat transfer experiments using two narrow-band TLCs. The method is validated through error analysis in terms of the random uncertainties in the measured temperatures. It is shown how the uncertainties in heat transfer coefficient and free stream temperature can be reduced. The general method described in this paper is applicable to many heat transfer models with unknown free stream temperature

  2. A high-temperature, high-pressure, silver-silver chloride reference electrode

    International Nuclear Information System (INIS)

    King, F.; Bailey, M.G.; Clarke, C.F.; Ikeda, B.M.; Litke, C.D.; Ryan, S.R.

    1989-05-01

    A high-temperature, high-pressure, silver-silver chloride reference electrode is described. This report is meant to serve as a user's guide to the experimentalist. Consequently, the design and construction of the electrode are dealt with in some detail. The problems that may be encountered, along with their possible causes and remedies, are also discussed. Conversion factors are given for both internal and external reference electrodes, so that measured potentials can be related to the standard hydrogen electrode scale

  3. Hormonal, Biochemical and Haematological Changes in Response to Acute Hyperthermia in Rabbits

    International Nuclear Information System (INIS)

    Zahran, N.A.R.M.

    2004-01-01

    Today, hyperthermia plays a significant role in the evidence-based on treatment of cancer patients. Such promising endeavor is due to the fact that neoplastic cells are more heat sensitive than normal cells. the prospect of using hyperthermia alone to treat cancer tumours is appealing because hyperthermia is a physical treatment and so would have fewer side effects than chemotherapy or radiotherapy and, it could be used in combination with these therapeutic approaches. much more consistent evidence has been obtained experimentally, and continuing clinical interest has been encouraged by confirmation that, at relatively low temperature (37-41.5 C), heat enhances cell growth and may well enhance also the growth and proliferation of tumours, while above 45 C heat begins to damage both normal and malignant cells in both animal and human. So, the goal is to achieve a selective temperature elevation between 42-45 C at the tumour site while maintaining healthy tissue temperatures in a physiological save range.This study was undertaken to investigate the effect of acute whole body hyperthermia , (WBH) (rectal temperature 43 c) on biochemical , hormonal and haematological changes in normal healthy local strain (baladi) rabbits.The thermal late effects (recovery) at 24 hr-post whole body hyperthermia was also undertaken , in the attempt to evaluate the degree of safety , when hyperthermia is applied in the clinic for treating cancer and other diseases

  4. Development of Radiation-hard Bandgap Reference and Temperature Sensor in CMOS 130 nm Technology

    CERN Document Server

    Kuczynska, Marika; Bugiel, Szymon; Firlej, Miroslaw; Fiutowski, Tomasz; Idzik, Marek; Michelis, Stefano; Moron, Jakub; Przyborowski, Dominik; Swientek, Krzysztof

    2015-01-01

    A stable reference voltage (or current) source is a standard component of today's microelectronics systems. In particle physics experiments such reference is needed in spite of harsh ionizing radiation conditions, i.e. doses exceeding 100 Mrads and fluences above 1e15 n/cm2. After such radiation load a bandgap reference using standard p-n junction of bipolar transistor does not work properly. Instead of using standard p-n junctions, two enclosed layout transistor (ELTMOS) structures are used to create radiation-hard diodes: the ELT bulk diode and the diode obtained using the ELTMOS as dynamic threshold transistor (DTMOS). In this paper we have described several sub-1V references based on ELTMOS bulk diode and DTMOS based diode, using CMOS 130 nm process. Voltage references the structures with additional PTAT (Proportional To Absolute Temperature) output for temperature measurements were also designed. We present and compare post-layout simulations of the developed bandgap references and temperature sensors, w...

  5. Development of high temperature reference electrodes for potentiometric analyses in supercritical water environments

    International Nuclear Information System (INIS)

    Tung Yuming; Yeh Tsungkuang; Wang Meiya

    2014-01-01

    A specifically designed reference electrode was developed for analyzing the electrochemical behaviors of alloy materials in supercritical water (SCW) environments and identifying the associated electrochemical parameters. In this study, Ag/AgCl reference electrodes and Zr/ZrO 2 reference electrodes suitable for high-temperature applications were manufactured and adopted to measure the electrochemical corrosion potentials (ECPs) of 304L stainless steel (SS) and nickel-based alloy 625 in SCW environments with various amounts of dissolved oxygen (DO). The Ag/AgCl reference electrode made in this laboratory was used as a calibration base for the laboratory-made Zr/ZrO 2 reference electrode at high temperatures up to 400degC. The two reference electrodes were then used for ECP measurements of 304L SS and alloy 625 specimens in 400degC SCW with various DO levels of 300 ppb, 1 ppm, 8.3 ppm, and 32 ppm and under deaerated conditions. The outcome indicated that concentration increases in DO in the designated SCW environment would yield increases in ECP of the two alloys and they exhibited different ECP responses to DO levels. In addition, the laboratory-made Zr/ZrO 2 reference electrode was able to continuously operate for several months and delivered consistent and steady ECP data of the specimens in SCW environments. (author)

  6. Results of the LIRES Round Robin test on high temperature reference electrodes for LWR applications

    Energy Technology Data Exchange (ETDEWEB)

    Bosch, R.W. [SCK.CEN, Nuclear Research Centre Belgium, Boeretang 200, B-2400 Mol (Belgium); Nagy, G. [Magyar Tudomanyos Akademia KFKI Atomenergia Kutatointezet, AEKI, Konkoly Thege ut 29-33, 1121 Budapest (Hungary); Feron, D. [CEA Saclay, 91191 Gif-Sur-Yvette Cedex (France); Navas, M. [CIEMAT, Edificio 30, Dpto. Fision Nuclear, Avda. Complutense 22, 28040 Madrid, (Spain); Bogaerts, W. [KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven (Belgium); Karnik, D. [Nuclear Research Institute, NRI, Rez (Czech Republic); Dorsch, T. [Framatone ANP, Inc., Charlotte, North Carolina (United States); Molander, A. [Studsvik AB SE-611 82 Nykoeping (Sweden); Maekelae, K. [Materials and Structural Integrity, VTT Technical Research Centre of Finland, Kemistintie 3, P.O. Box 1704, FIN-02044 VTT (Finland)

    2004-07-01

    A European sponsored research project has been started on 1 October 2000 to develop high temperature reference electrodes that can be used for in-core electrochemical measurements in Light Water Reactors (LWR's). This LIRES-project (Development of Light Water Reactor Reference Electrodes) consists of 9 partners (SCK-CEN, AEKI, CEA, CIEMAT, KU Leuven, NRI Rez, Framatone ANP, Studsvik Nuclear and VTT) and will last for four years. The main objective of this LIRES project is to develop a reference electrode, which is robust enough to be used inside a LWR. Emphasize is put on the radiation hardness of both the mechanical design of the electrode as the proper functioning of the electrode. A four steps development trajectory is foreseen: (1) To set a testing standard for a Round Robin, (2) To develop different reference electrodes, (3) To perform a Round Robin test of these reference electrodes followed by selection of the best reference electrode(s), (4) To perform irradiation tests under appropriate LWR conditions in a Material Test Reactor (MTR). Four different high temperature reference electrodes have been developed and are being tested in a Round Robin test. These electrodes are: A Ceramic Membrane Electrode (CME), a Rhodium electrode, an external Ag/AgCl electrode and a Palladium electrode. The presentation will focus on the results obtained with the Round Robin test. (authors)

  7. Mechanisms of hyperthermia induced radiatiosensitization for treatment of human papillomavirus positive tumors

    International Nuclear Information System (INIS)

    Oei, Arlene; Leeuwen, Caspar van; Stalpers, Lukas; Rodermond, Hans; Kok, Petra; Crezee, Hans; Franken, Nicolaas

    2016-01-01

    HPV is associated with cervical cancer, the third most common cancer in women. In over 70% of cervical cancers, the high-risk HPV-types 16 and 18 are found. In these tumors, functionality of p53 is suppressed by the presence of protein E6. Hyperthermia is a clinical application of heat in which tumour temperatures are raised to 40-43°C and combined hyperthermia with radiation is very effective in the treatment of cervical cancer

  8. Comparative evaluation of combined irradiation and hyperthermia versus irradiation alone

    International Nuclear Information System (INIS)

    Sawas-Dimopoulou, C.; Iordanou, I.; Uzunoglu, N.; Dardoufas, K.; Kouloulias, V.; Maris, T.; Kotaridis, S.

    1994-01-01

    Controvesy remains as to the treatment schedule producing better results in combined hyperthermia and X-ray therapy. Our experience concerning combined therapy of the solid tumour Walker carcinoma is reported. Male Wistar rats were submitted to treatment on the ninth day after transplantation of the tumour. Two groups of rats received either a therapeutic X-ray dose of 800 cGy by a 6-MeV linear accelerator (Mevatron, Siemens) or treatment by 432 MHz of microwaves with continuous control of tumour tissue temperature to 44±1 C for 45 min. Another group of rats was submitted to a combined treatment, with X-ray therapy preceding hyperthermia by 24 h. The last group of animals constituted the control rats. Greater tumour regression and longer survival times were obtained with the combined treatment. The gain factor for survival time was equal to 1.85 after combined treatment compared with 1.30 after X-ray therapy and 1.05 after hyperthermia. In conclusion, the results suggest that in the above schedule of combined treatment, hyperthermia applied to a solid tumour 24 h after a single dose of X-rays enhances the beneficial effect of therapy. (orig.)

  9. Effects of hyperthermia on the hamster immune system

    International Nuclear Information System (INIS)

    Gangavalli, R.; Cain, C.A.; Tompkins, W.A.F.

    1984-01-01

    In previous studies, the authors have shown that hyperthermia can enhance antibody-complement chytotoxicity of hamster and human tumor cells. Moreover, whole body microwave exposure of hamsters resulted in activation of peritoneal macrophages to a viricidal state and transient suppression of natural killer (NK) cell activity. In this study, the authors compare the effects of whole body heating by microwaves or by an environmental chamber (hot air) on the hamster immune system. Microwave exposure (25mW/cm/sup 2/; 1 hr) caused viricidal activation of peritoneal macrophages which resulted in restriction of vaccinia and vesicular stomatitis virs (VSV) growth. However, heating in an environmental chamber (41 0 C; 1 hr) did not activate macrophages to a viricidal state. Both microwave and hot air hyperthermia caused significant augmentation of antibody producing spleen cell response to sheep red blood cells (SRBC), using the Jerne hymolytic plaque assay, four days post exposure and immunization with SRBC. Natural killer spleen cell cytotoxicity was suppressed by microwave and hot air hyperthermia showing that NK lymphocytes are extremely sensitive to changes in temperature. These alterations in cellular immune response due to hyperthermia could be of significance in treatment of tumors and viral infections

  10. Hyperthermia generated by Foucault currents for oncological treatments with COMSOL

    International Nuclear Information System (INIS)

    Romero C, R. L.; Cordova F, T.; Basurto I, G.; Guzman C, R.; Castro L, J.

    2017-10-01

    The hyperthermia generated by variable magnetic fields is a promising power method for oncological therapy, because apoptosis is induced in tumor cells at temperatures between 42 and 45 degrees Celsius. It is known that an alternating magnetic field on the FeO 4 magnetite particles produces heat through three paths: is generated by parasitic currents, lost in hysteresis cycles and losses by magnetization relaxation; taking advantage of the energy losses through the joule effect and the transformation into heat, a simulation is shown in COMSOL about the temporal distribution of temperature in transformed biological systems, to have an estimate of the properties and behavior of the temperature gradient when magnetic hyperthermia is generated in human transformed tissue. (Author)

  11. Malignant Hyperthermia and Idiopathic HyperCKemia

    Directory of Open Access Journals (Sweden)

    Pashtoon Murtaza Kasi

    2011-01-01

    Full Text Available Malignant hyperthermia (MH is a rare but life-threatening condition that is more frequently encountered and discussed within the anesthesia literature. Here we through a case specifically discuss the susceptibility of individuals and/or families with asymptomatic unexplained elevations of creatine kinase (CK, also frequently referred to as hyperCKemia or idiopathic hyperCKemia (IHCK in recent reports. The clinical implications would be to underscore the importance of this as a susceptibility to developing MH and highlight the importance of genetic susceptibility testing in such cases. Anesthesiologists and critical care intensivists as well as primary care physicians should keep this in mind when seeing patients with asymptomatic hyperCKemia and potentially inform them about the possibility of developing MH if exposed to triggering agents. Genetic susceptibility testing should be considered if available and family members should also receive nontriggering agents when undergoing anesthesia and wear Medic Alert tags.

  12. A low temperature drift coefficient crystal-less frequency reference clock compensated by temperature sensor for microsystem

    Science.gov (United States)

    Gao, Zhiqiang; Wu, Ruixuan; Wang, Yuteng; Gao, Yuan; Liu, Xiaowei; Zhu, Jiaqi

    2018-05-01

    Quartz oscillator has been widely used as reference clock source in the microsystems due to its good performance. But a good crystal oscillator costs too much and its bulky size is not desired. This paper aims at designing an alternative integrated oscillator to replace the external quartz oscillator. The proposed circuit used maneatis delay cell to construct a ring oscillator for its superior linear I-V characteristic. As for a frequency reference clock, its frequency stability over temperature is required at first. After detailed mathematical deducing and careful analysis, a formula is proposed to describe the relationship between desired control voltage and temperature by assuming the frequency as constant. This paper utilized bipolar transistor as the temperature sensor, combining it with CTAT current source and resistor to create a first-order temperature compensation control voltage. The chip with typical frequency of 10 MHz was fabricated in a 0.35 μm CMOS technology and occupied 0.45 mm2. The measured results show that the frequency variation is ±0.2% for supply changes from 4.8 V to 5 V, and frequency variation is 48 ppm when the temperature change is from ‑40∘C to 85∘C, while the average current of the tested chip consumes 50 μA from 5 V.

  13. Predicting thermal history a-priori for magnetic nanoparticle hyperthermia of internal carcinoma

    Science.gov (United States)

    Dhar, Purbarun; Sirisha Maganti, Lakshmi

    2017-08-01

    This article proposes a simplistic and realistic method where a direct analytical expression can be derived for the temperature field within a tumour during magnetic nanoparticle hyperthermia. The approximated analytical expression for thermal history within the tumour is derived based on the lumped capacitance approach and considers all therapy protocols and parameters. The present method is simplistic and provides an easy framework for estimating hyperthermia protocol parameters promptly. The model has been validated with respect to several experimental reports on animal models such as mice/rabbit/hamster and human clinical trials. It has been observed that the model is able to accurately estimate the thermal history within the carcinoma during the hyperthermia therapy. The present approach may find implications in a-priori estimation of the thermal history in internal tumours for optimizing magnetic hyperthermia treatment protocols with respect to the ablation time, tumour size, magnetic drug concentration, field strength, field frequency, nanoparticle material and size, tumour location, and so on.

  14. Visual function and retinal vessel diameters during hyperthermia in man

    DEFF Research Database (Denmark)

    Jensen, Bettina Hagström; Bram, Thue; Kappelgaard, Per

    2017-01-01

    .01), a 10.6-mmHg mean reduction in diastolic blood pressure (p vein...... laser ophthalmoscopy was used to measure retinal trunk vessel diameters. Assessment was made at baseline, during hyperthermia and after cooling. RESULTS: The induction of a mean increase in core body temperature of 1.02°C was associated with a 7.15-mmHg mean reduction in systolic blood pressure (p

  15. A survey of reference electrodes for high temperature waters; Oeversikt av referenselektroder i hoegtemperaturvatten

    Energy Technology Data Exchange (ETDEWEB)

    Molander, A.; Eriksson, Sture; Pein, K. [Studsvik Nuclear, Nykoeping (Sweden)

    2000-11-01

    In nuclear power plants, corrosion potential measurements are used to follow the conditions for different corrosion types in reactor systems, particularly IGSCC in BWRs. The goal of this work has been to give a survey of reference electrodes for high temperature water, both those that are used for nuclear environments and those that are judged to possible future development. The reference electrodes that are used today in nuclear power plants for corrosion potential measurements are of three types. Silver chloride electrodes, membrane electrodes and platinum electrodes (hydrogen electrodes). The principals for their function is described as well as the conversion of measured potentials to the SHE scale (Standard Hydrogen Electrode). Silver chloride electrodes consist of an inner reference system of silver chloride in equilibrium with a chloride solution. The silver chloride electrode is the most common reference electrode and can be used in several different systems. Platinum electrodes are usually more robust and are particularly suitable to use in BWR environment to follow the hydrogen dosage, but have limitations at low and no hydrogen dosage. Ceramic membrane electrodes can be with different types of internal reference system. They were originally developed for pH measurements in high temperature water. If pH is constant, the membrane electrode can be used as reference electrode. A survey of ceramic reference electrodes for high temperature water is given. A ceramic membrane of the type used works as an oxygen conductor, so the potential and pH in surrounding medium is in equilibrium with the internal reference system. A survey of the lately development of electrodes is presented in order to explain why the different types of electrodes are developed as well as to give a background to the possibilities and limitations with the different electrodes. Possibilities of future development of electrodes are also given. For measurements at low or no hydrogen dosage

  16. Frequency Of Hyperthermia In Acute Ischemic Stroke Patients Visiting A Tertiary Care Hospital

    International Nuclear Information System (INIS)

    Maheshwari, A. K.; Kumar, P.; Alam, M. T.; Aurangzeb, M.; Imran, K.; Masroor, M.; Parkash, J.

    2016-01-01

    Objective: To determine the frequency of hyperthermia in acute ischemic stroke patients visiting a tertiary care hospital in a developing country. Study Design: Cross-sectional, observational study. Place and Duration of Study: Medical Wards of Civil Hospital, Karachi, from January to June 2013. Methodology: Patients aged = 18 years of either gender with acute ischemic stroke presenting within 24 hours of onset of symptoms were included. Written informed consent was obtained from all participants as well as approval of ethical review committee of the institute. Axillary temperature by mercury thermometer was monitored at the time of admission and after every 6 hours for 3 days. The data was analyzed using SPSS version 17.0 (SPSS Inc., IL, Chicago, USA). Result: A total of 106 patients of ischemic stroke were included. The mean age of enrolled participants was 60.1 ±9.5 years. Among these, 61 (57.5 percentage) were males and 45 (42.5 percentage) females. Among all patients, 51.9 percentage presented with loss of consciousness, 30.2 percentage with slurred speech, 77.4 percentage with limb weakness, and 9.4 percentage with decrease vision. A total of 17 (16 percentage) patients with ischemic stroke developed hyperthermia. When the prevalence of hyperthermia was stratified according to age, among patients of < 60 years of age, 26 percentage developed hyperthermia compared to 7.1 percentage in patients of = 60 years of age (p=0.008). On gender stratification, among male patients, 14.8 percentage developed hyperthermia compared to 17.8 percentage in female patients (p=0.43). Conclusion: It is concluded from this study that the frequency of hyperthermia in ischemic stroke was 16 percentage and it should be looked for as it has significant impact on the outcome. The hyperthermia was significantly more common in younger adults as compared to older adults. However, gender had no influence on the prevalence rate of hyperthermia. (author)

  17. Hyperthermia and PARP1-inhibition for sensitization of radiation and cisplatin treatment of cervical carcinoma cells

    International Nuclear Information System (INIS)

    Franken, Nicolaas; Oei, Arlene; Leeuwen, Caspar van; Stalpers, Lukas; Rodermond, Hans; Bel, Arjan; Kok, Petra; Crezee, Hans

    2014-01-01

    Ionizing radiation causes single and double strand breaks (SSBs and DSBs). DSBs are among the most critical DNA lesions and can be repaired via either non-homologous end joining (NHEJ) in which PARP1, Ku70 and DNA-PKcs are important, or homologous recombination (HR), where BRCA2 and Rad51 are essential. Hyperthermia disturbs HR by temporary inactivation of BRCA2. Cisplatin disrupts NHEJ and PARP1-inhibitor blocks Poly-(ADP-ribose)polymerase- 1, which is important in SSB repair, NHEJ and backup-NHEJ. Our goal was to investigate the additional effectiveness of hyperthermia and PARP1-inhibition on radiation and/or cisplatin treatment. Cervical carcinoma cells (SiHa) were treated at different temperature levels levels (41.0-43.0℃, PARP1-inhibitor (100 μM; NU1025), gamma-irradiation doses (0-8 Gy) or cisplatin (1'R for 1 h). Clonogenic assays were carried out to measure survival and γH2AX staining was used to visualize DSBs. To elucidate mechanisms of action expression levels of DNA repair proteins BRCA2 and DNA-PKcs were investigated after 42.0℃ (1 h) using western blot. Combined hyperthermia and radiation resulted in an increased number of γH2AX foci as compared to radiation alone. Hyperthermia treatment in combination with cisplatin and PARP1 inhibitor and with radiation and PARP1 inhibitor significantly decreased cell survival. Western blot demonstrated a decreased expression of BRCA2 protein at 30 min after hyperthermia treatment. Adding PARP1-inhibitor significantly improves the effectiveness of combined hyperthermia radiotherapy and combined hyperthermia-cisplatin treatment on cervical carcinoma cells. Hyperthermia affects DNA-DSB repair as is indicated by increased γH2AX foci numbers and decreased BRCA2 expression. (author)

  18. Hyperthermia of locally advanced or recurrent gynecological cancer. The effect of combination with irradiation or chemotherapy

    International Nuclear Information System (INIS)

    Terashima, Hiromi; Imada, Hajime; Egashira, Kanji; Nakata, Hajime; Kunugita, Naoki; Matsuura, Yuusuke; Kashimura, Masamichi

    1995-01-01

    Between May 1986 and April 1994, 15 patients with advanced or recurrent gynecological cancer were treated with combined therapy of hyperthermia and irradiation or chemotherapy at UOEH Hospital. Initial cases were treated by hyperthermia combined with irradiation in 4 and with chemotherapy in 2. Recurrent 9 cases were treated by hyperthermia combined with chemotherapy or by hyperthermia alone. Radiotherapy was given in a conventional way 5 fractions per week and hyperthermia was performed using RF capacitive heating equipment, Thermotron RF-8, once or twice a week. Intratumoral temperature was measured by thermocouple inserted into the tumor and kept at 42-44degC for 30-40 minutes. Complete response (CR) and partial response (PR), defined as 50% or more regression, was obtained in 8/15 (53%). Response rates (CR+PR/all cases) were good in initially treated cases (5/6, 83%), irradiated cases (7/8, 88%) and cases hearted over 42degC (7/9, 78%). Combined therapy of hyperthermia and radiotherapy seemed to be useful for controlling advanced gynecological cancers. (author)

  19. The application of hyperthermia in regional chemotherapy.

    Science.gov (United States)

    Di Filippo, F; Anzà, M; Rossi, C R; Cavaliere, F; Botti, C; Lise, M; Garinei, R; Giannarelli, D; Vasselli, S; Zupi, G; Cavaliere, R

    1998-01-01

    To evaluate the role of hyperthermia combined with chemotherapy in the loco-regional treatment of tumors, a retrospective analysis was done with 228 limb melanoma patients treated with hyperthermic antiblastic perfusion (HAP). A series of treatment- and tumor-related prognostic factors was analyzed to establish their influence on tumor response, loco-regional control, and survival. Concerning tumor response, the logistic model showed that the number of lesions and the minimal tumor temperature (min T) maintained their individual predictive values (P < 0.000001 and P = 0.04, respectively). For loco-regional control, only the number of lesions had a significant predictive value. No direct correlation was found between the treatment-related variables and loco-regional control. However, the 5-year survival rate was significantly higher for patients who achieved a complete response (CR) (51.5%, P = 0.0033) as compared to those who did not (33.3%), providing indirect evidence of the role of the treatment. Multivariate analysis showed that both disease-free and overall survival are strongly influenced by numerous clinical variables and the min T always maintained its significance. When analyzing the subgroup of 119 patients evaluable for tumor response, the Cox model selected the tumor response as the dominant factor for both disease-free and overall survival. These data seem to demonstrate that the optimization of treatment parameters is crucial in determining the CR rate, which, in turn, positively affects the disease outcome. HAP is the treatment of choice for recurrent limb melanoma, and hyperthermia plays an important role in exploiting the efficacy of this technique.

  20. Radiation plus local hyperthermia versus radiation plus the combination of local and whole-body hyperthermia in canine sarcomas

    International Nuclear Information System (INIS)

    Thrall, Donald E.; Prescott, Deborah M.; Samulski, Thaddeus V.; Rosner, Gary L.; Denman, David L.; Legorreta, Roberto L.; Dodge, Richard K.; Page, Rodney L.; Cline, J. Mark; Lee Jihjong; Case, Beth C.; Evans, Sydney M.; Oleson, James R.; Dewhirst, Mark W.

    1996-01-01

    Purpose: The purpose of this study was to assess the effect of increasing intratumoral temperatures by the combination of local hyperthermia (LH) and whole body hyperthermia (WBH) on the radiation response of canine sarcomas. Methods and Materials: Dogs with spontaneous soft tissue sarcomas and no evidence of metastasis were randomized to be treated with radiation combined with either LH alone or LH + WBH. Dogs were accessioned for treatment at two institutions. The radiation dose was 56.25 Gy, given in 25 2.25 Gy daily fractions. Two hyperthermia treatments were given; one during the first and one during the last week of treatment. Dogs were evaluated after treatment for local recurrence, metastasis, and complications. Results: Sixty-four dogs were treated between 1989 and 1993. The use of LH+WBH resulted in statistically significant increases in the low and middle regions of the temperature distributions. The largest increase was in the low temperatures with median CEM 43 T90 values of 4 vs. 49 min for LH vs. LH + WBH, respectively (p < 0.001). There was no difference in duration of local tumor control between hyperthermia groups (p = 0.59). The time to metastasis was shorter for dogs receiving LH + WBH (p = 0.02); the hazard ratio for metastatic disease for dogs in the LH + WBH group was 2.5 (95% confidence interval, 1.2-5.4) with respect to dogs in the LH group. Complications were greater in larger tumors and in tumors treated with LH + WBH. Conclusion: The combination of LH + WBH with radiation therapy, as described herein, was not associated with an increase in local tumor control in comparison to use of LH with radiation therapy. The combination of LH + WBH also appeared to alter the biology of the metastatic process and was associated with more complications than LH. We identified no rationale for further study of LH + WBH in combination with radiation for treatment of solid tumors

  1. Effect of hyperthermia on replicating chromatin

    International Nuclear Information System (INIS)

    Warters, R.L.; Roti Roti, J.L.

    1981-01-01

    The extent of heat-induced structural alterations in chromatin containing nascent (pulse-labeled) DNA was assayed using the enzyme micrococcal nuclease. The basic nucleosome structure in nascent and mature chromatin of S-phase cells appeared unaltered for up to 16 hr after exposure to hyperthermic temperatures as high as 48 0 C for 15 min. However, the rate of nuclease digestion of DNA in both nascent and mature chromatin is inhibited following exposure to hyperthermic temperatures. In unheated cells, pulse-labeled nascent DNA matured into mature chromatin structure with a half-time of 2.5 min. The half-time for the maturation of pulse-labeled DNA from nascent into mature chromatin increased in a linear manner as a function of increasing temperature of exposure with constant heating time at temperatures above 43 0 C. Both the reduced nuclease digestibility of nascent DNA and the increased time for chromatin structural changes could be due to the increased protein mass of chromatin following hyperthermia

  2. An experimental study on the alteration of thermal enhancement ratio by combination of split dose hyperthermia irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun Ok; Kim, Hee Seup [Ewha Womens University College of Medicine, Seoul (Korea, Republic of)

    1983-06-15

    The study was undertaken to evaluate the alteration of thermal enhancement ratio as a function of time intervals between two split dose hyperthermias followed by irradiation. For the experiments, 330 mice were divided into 3 groups; the first, 72 mice were used to evaluate the heat reaction by single dose hyperthermia and heat resistance by split dose hyperthermia, the second, 36 mice were used to evaluate the radiation reaction by irradiation only, and the third, 222 mice were used for TER observation by combination of single dose hyperthermia and irradiation, and TER alteration by combination of split dose hyperthermia and irradiation. For each group the skin reaction score of mouse tail was used for observation and evaluation of the result of heat and irradiation. The results obtained are summarized as follows: 1. The heating time resulting 50% necrosis (ND{sub 5}0) Was 101 minutes in 43 .deg. C and 24 minutes in 45 .deg. C hyperthermia, which indicated that three is reciprocal proportion between temperature and heating time. 2. Development of heat resistance was observed by split dose hyperthermia. 3. The degree of skin reaction by irradiation only was increased proportionally as a function of radiation dose, and calculated radiation dose corresponding to skin score 1.5 (D{sub 1}.5) was 4,137 rads. 4. Obtained thermal enhancement ratio by combination of single dose hyperthermia and irradiation was increased proportionally as a function of heating time. 5. Thermal enhancement ratio was decreased by combination of split dose hyperthermia and irradiation, which was less intense and lasted longer than development of heat resistance. In summary, these studies indicate that the alteration of thermal enhancement ratio has influence on heat resistance by split dose hyperthermia and irradiation.

  3. Computational evaluation of amplitude modulation for enhanced magnetic nanoparticle hyperthermia.

    Science.gov (United States)

    Soetaert, Frederik; Dupré, Luc; Ivkov, Robert; Crevecoeur, Guillaume

    2015-10-01

    Magnetic nanoparticles (MNPs) can interact with alternating magnetic fields (AMFs) to deposit localized energy for hyperthermia treatment of cancer. Hyperthermia is useful in the context of multimodality treatments with radiation or chemotherapy to enhance disease control without increased toxicity. The unique attributes of heat deposition and transfer with MNPs have generated considerable attention and have been the focus of extensive investigations to elucidate mechanisms and optimize performance. Three-dimensional (3D) simulations are often conducted with the finite element method (FEM) using the Pennes' bioheat equation. In the current study, the Pennes' equation was modified to include a thermal damage-dependent perfusion profile to improve model predictions with respect to known physiological responses to tissue heating. A normal distribution of MNPs in a model liver tumor was combined with empirical nanoparticle heating data to calculate tumor temperature distributions and resulting survival fraction of cancer cells. In addition, calculated spatiotemporal temperature changes were compared among magnetic field amplitude modulations of a base 150-kHz sinusoidal waveform, specifically, no modulation, sinusoidal, rectangular, and triangular modulation. Complex relationships were observed between nanoparticle heating and cancer tissue damage when amplitude modulation and damage-related perfusion profiles were varied. These results are tantalizing and motivate further exploration of amplitude modulation as a means to enhance efficiency of and overcome technical challenges associated with magnetic nanoparticle hyperthermia (MNH).

  4. New Temperature References and Sensors for the Next Generation of Nuclear Power Plants

    International Nuclear Information System (INIS)

    Sadli, M.; Deuze, T.; Failleau, G.; Mokdad, S.-A.; Podesta, M. de; Edwards, G.; Elliott, C.-J.; Pearce, J.-V.; Sutton, G.; Del Campo, D.; Garcia-Izquierdo, C.; Fourrez, S.; Laurie, M.

    2013-06-01

    In preparation for the new challenges posed by the higher temperature environments which are likely to be encountered in the next generation of nuclear power plants, to maintain the safety and to ensure the long-term reliability of such plants, it is crucial that new temperature sensors and methods for in-situ measurement are investigated and developed. This is the general objective of the first work package of the joint research project, ENG08 MetroFission, funded in the framework of the European metrology research program. This paper will review the results obtained in developing and testing new temperature sensors and references during the course of the project. The possible continuation of these activities in the future is discussed. (authors)

  5. Thermometric analysis of intra-cavitary hyperthermia for esophageal cancer.

    Science.gov (United States)

    Qi, C; Li, D J

    1999-01-01

    Thermometric analysis was carried out in 51 patients with esophageal cancer treated with intra-cavitary hyperthermia combined with radio chemotherapy, to test whether temperature index (T20, T50) and T90) could be used as an indicator for tumour control. Hyperthermia was administered by intra-cavitary microwave applicator. The T20, T50 and T90 were deducted from the temperature sensors T0 and T3 situated at the center of the tumour surface and 3cm from it. Eighteen patients with local control > or =36 months were named long term control patients (LC), 24 patients with local recurrence within 24 months (LR) (there were no events occurring between 24 and 36 months) and nine patients died of metastasis without local recurrence (DM). The overall survival rates were 80.4 +/- 5.6% at 1 year, 38.3 +/- 6.9% at 3 years and 31 +/- 6.7% at 5 years, respectively. Chi-square test showed no influence of the number of hyperthermia sessions on the local control (p > 0.25). The 5-year local control rate was 18.8% for the patients with T90 or = 43 degrees C (p < 0.01). The average T90 was 43.76 +/- 0.74 degrees C for the LC patients and 43.17 +/- 0.57 degrees C for those LR (p = 0.024). The mean T90 was higher than 43 degrees C in 94.4% of LC, whereas in 58.8% of LR. The study suggested that T90 was a good parameter for thermal dose in the intracavitary hyperthermia for the treatment of esophageal cancer.

  6. Preferential radiosensitization of human prostatic carcinoma cells by mild hyperthermia

    International Nuclear Information System (INIS)

    Ryu, Samuel; Brown, Stephen L.; Kim, Sang-Hie; Khil, Mark S.; Kim, Jae Ho

    1996-01-01

    Purpose: Recent cell culture studies by us and others suggest that some human carcinoma cells are more sensitive to heat than are rodent cells following mild hyperthermia. In studying the cellular mechanism of enhanced thermosensitivity of human tumor cells to hyperthermia, prostatic carcinoma cells of human origin were found to be more sensitive to mild hyperthermia than other human cancer cells. The present study was designed to determine the magnitude of radiosensitization of human prostatic carcinoma cells by mild hyperthermia and to examine whether the thermal radiosensitization is related to the intrinsic thermosensitivity of cancer cells. Methods and Materials: Two human prostatic carcinoma cell lines (DU-145 and PC-3) and other carcinoma cells of human origin, in particular, colon (HT-29), breast (MCF-7), lung (A-549), and brain (U-251) were exposed to temperatures of 40-41 deg. C. Single acute dose rate radiation and fractionated radiation were combined with mild hyperthermia to determine thermal radiosensitization. The end point of the study was the colony-forming ability of single-plated cells. Results: DU-145 and PC-3 cells were found to be exceedingly thermosensitive to 41 deg. C for 24 h, relative to other cancer cell lines. Ninety percent of the prostatic cancer cells were killed by a 24 h heat exposure. Prostatic carcinoma cells exposed to a short duration of heating at 41 deg. C for 2 h resulted in a substantial enhancement of radiation-induced cytotoxicity. The thermal enhancement ratios (TERs) of single acute dose radiation following heat treatment 41 deg. C for 2 h were 2.0 in DU-145 cells and 1.4 in PC-3 cells. The TERs of fractionated irradiation combined with continuous heating at 40 deg. C were similarly in the range of 2.1 to 1.4 in prostate carcinoma cells. No significant radiosensitization was observed in MCF-7 and HT-29 cells under the same conditions. Conclusion: The present data suggest that a significant radiosensitization of

  7. Effect of the damage by radiation on the reference temperature T0 of ferritic steel

    International Nuclear Information System (INIS)

    Villanueva O, A.

    2004-01-01

    Presently work studies the effect that produces the irradiation in ferritic steels, on the reference temperature T 0 (intrinsic characteristic of the fracture tenacity in the area of ductile-fragile transition), applying the approach of the Master curve that is based on the norm Astm E-1921. For it it was elaborated a methodology and procedure for test tubes type Charpy according to the standard before mentioned. Due to the ferritic steels are used mainly in pressure vessels to the reactor (RPV) of nuclear power plants; in the samples it was simulated the effect of the damage for irradiation through a thermal treatment that induced the precipitation of the carbides and sulfurs in the limits of grain (one of the modifications suffered in the irradiated materials); it was made a comparison later with material samples in initial state (without thermal treatment), used as witness sample, by means of assays of fracture mechanics, specifically flexion in three points; this way with it to observe the effect of the damage for irradiation in the reference temperature (T 0 ). This temperature (T 0 ) it is a very important parameter in the mechanical property of the material called fracture tenacity; which at the moment gives the rule for the verification of structural integrity of the RPV. As a result of this it was observed an increase in the reference temperature in the material in fragilezed state with respect to the initial state of 31.75 C. They were carried out metallographic analysis and fractographs of the assayed surface finding carbide inclusions and sulfurs that in theory of the Master Curve they are initiators of cracks and of a possible catastrophic flaw of the material. At the moment the Division of Scientific Investigation of the ININ is carrying out activities in the Nucleo electric Central of Laguna Verde (CNLV) related with the program of surveillance of the materials of the vessel of the unit 2, as well as projects of structural integrity financed by the

  8. Polymer coated fiber Bragg grating thermometry for microwave hyperthermia.

    Science.gov (United States)

    Saxena, Indu Fiesler; Hui, Kaleo; Astrahan, Melvin

    2010-09-01

    Measuring tissue temperature distribution during electromagnetically induced hyperthermia (HT) is challenging. High resistance thermistors with nonmetallic leads have been used successfully in commercial HT systems for about three decades. The single 1 mm thick temperature sensing element is mechanically moved to measure tissue temperature distributions. By employing a single thermometry probe containing a fixed linear sensor array temperature, distributions during therapy can be measured with greater ease. While the first attempts to use fiber Bragg grating (FBG) technology to obtain multiple temperature points along a single fiber have been reported, improvement in the detection system's stability were needed for clinical applications. The FBG temperature sensing system described here has a very high temporal stability detection system and an order of magnitude faster readout than commercial systems. It is shown to be suitable for multiple point fiber thermometry during microwave hyperthermia when compared to conventional mechanically scanning probe HT thermometry. A polymer coated fiber Bragg grating (PFBG) technology is described that provides a number of FBG thermometry locations along the length of a single optical fiber. The PFBG probe developed is tested under simulated microwave hyperthermia treatment to a tissue equivalent phantom. Two temperature probes, the multiple PFBG sensor and the Bowman probe, placed symmetrically with respect to a microwave antenna in a tissue phantom are subjected to microwave hyperthermia. Measurements are made at start of HT and 85 min later, when a 6 degrees C increase in temperature is registered by both probes, as is typical in clinical HT therapy. The optical fiber multipoint thermometry probe performs highly stable, real-time thermometry updating each multipoint thermometry scan over a 5 cm length every 2 s. Bowman probe measurements are acquired simultaneously for comparison. In addition, the PFBG sensor's detection

  9. Austenitic chromium nickel steel as standard reference material in measurement of thermal and temperature conductivity

    International Nuclear Information System (INIS)

    Binkele, L.

    1990-01-01

    A niobium-stabilized CrNi steel with the NBS designation SRM 735 is introduced as WLF standard reference material in a report by Hust and Giarratano, for the temperature range 300-1200 K and for thermal conductivities around 20 W/mk. However, its specification does not show it to be a direct member of the DIN family of CrNi steels. This report should be regarded as a continuation and supplement to the above-mentioned efforts in America. On the one hand, a solution of a possibly too-narrow specification is aimed at for the reference material, where it is important how sensitive the thermal conductivity is to changes in the chemical composition and changes of the manufacturing parameters and what accuracy can be reached for the reference values with the best measurement techniques. On the other hand, the data base should be expanded and the accuracy of the reference curve should be improved if possible. (orig./MM) [de

  10. Reference-free fatigue crack detection using nonlinear ultrasonic modulation under various temperature and loading conditions

    Science.gov (United States)

    Lim, Hyung Jin; Sohn, Hoon; DeSimio, Martin P.; Brown, Kevin

    2014-04-01

    This study presents a reference-free fatigue crack detection technique using nonlinear ultrasonic modulation. When low frequency (LF) and high frequency (HF) inputs generated by two surface-mounted lead zirconate titanate (PZT) transducers are applied to a structure, the presence of a fatigue crack can provide a mechanism for nonlinear ultrasonic modulation and create spectral sidebands around the frequency of the HF signal. The crack-induced spectral sidebands are isolated using a combination of linear response subtraction (LRS), synchronous demodulation (SD) and continuous wavelet transform (CWT) filtering. Then, a sequential outlier analysis is performed on the extracted sidebands to identify the crack presence without referring any baseline data obtained from the intact condition of the structure. Finally, the robustness of the proposed technique is demonstrated using actual test data obtained from simple aluminum plate and complex aircraft fitting-lug specimens under varying temperature and loading variations.

  11. Meteorological Reference Years of Daily Mean Temperature during the Slighting Time

    International Nuclear Information System (INIS)

    Marchante Jimenez, M.; Ramirez Santigosa, L.; Navarro Fernandez, A.; Mora Lopez, L.; Sidrach de Cardona Ortin, M.

    2002-01-01

    In this work the characterization of the daily mean temperature during the sunlight time has been analyzed. An algorithm for the hourly series generation from extreme daily values has been applied to evaluate the daily mean temperature during the sunlight time. A generic algorithm has been enhanced as a function of the sunrise time. This algorithm allows taking into account the fractions related to the sunrise and sunset hours. This methodology has been applied in data from 45 Spanish stations, uniformly distributed in the Iberian Peninsula. Data for a period of 14 years has been used in most of locations, and once the interest variable has been calculated, the meteorological reference year of the daily mean temperature during the sunlight time has been evaluated in each stations. The next step is the evaluation of the daily mean temperature during the sunlight time in any point into the zone of evaluation, not only in the measured stations. From the result data in each measured station, an geographic information system has been used in order to calculate the interpolation, obtaining maps with a data each 5 km. for each of the 365 days of the year. Then, this results can be superposed with the solar radiation evaluation obtaining the input data for the sizing of the photovoltaic grid connected system in any point of the Spanish geography. (Author) 64 refs

  12. Methamphetamine-induced hyperthermia and dopaminergic neurotoxicity in mice: pharmacological profile of protective and nonprotective agents.

    Science.gov (United States)

    Albers, D S; Sonsalla, P K

    1995-12-01

    Neurotoxic doses of methamphetamine (METH) can cause hyperthermia in experimental animals. Damage sustained to dopaminergic nerve terminals by this stimulant can be reduced by environmental cooling or by pharmacological manipulation which attenuates the hyperthermia. Many pharmacological agents with very diverse actions protect against METH-induced neuropathology. Several of these compounds, as well as drugs which do not protect, were investigated to determine if there was a relationship between protection and METH-induced hyperthermia. Mice received METH with or without concurrent administration of other drugs and core (i.e., colonic) temperature was monitored during treatment. The animals were sacrificed > or = 5 days later and neostriatal tyrosine hydroxylase activity and dopamine were measured. Core temperature was significantly elevated (> or = 2 degrees C) in mice treated with doses of METH which produced > or = 90% losses in striatal dopamine but not in mice less severally affected (only 50% loss of dopamine). Concurrent treatment of mice with METH and pharmacological agents which protected partially or completely from METH-induced toxicity also prevented the hyperthermic response (i.e., dopamine receptor antagonists, fenfluramine, dizocilpine, alpha-methyl-p-tyrosine, phenytoin, aminooxyacetic acid and propranol). These findings are consistent with the hypothesis that the hyperthermia produced by METH contributes to its neuropathology. However, studies with reserpine, a compound which dramatically lowers core temperature, demonstrated that hyperthermia per se is not a requirement for METH-induced neurotoxicity. Although core temperature was elevated in reserpinized mice treated with METH as compared with reserpinized control mice, their temperatures remained significantly lower than in nonreserpinized control mice. However, the hypothermic state produced in the reserpinized mice did not provide protection from METH-induced toxicity. These data demonstrate

  13. Dynamic Reference Electrode development for redox potential measurements in fluoride molten salt at high temperature

    International Nuclear Information System (INIS)

    Durán-Klie, Gabriela; Rodrigues, Davide; Delpech, Sylvie

    2016-01-01

    Measurement of redox potential in fluoride media is a major problem due to the difficulty to design a reference electrode with high stability, high mechanical resistance and high accuracy. In the frame of molten salt reactor studies, a dynamic reference electrode (DRE) is developed to measure redox potential in fluoride molten salt at high temperature. DRE is based on the in-situ generation of a transient redox system. The choice of the redox couple corresponds to the cathodic limit of the molten salt considered. As a preliminary step, the demonstration of feasibility of generating a DRE was done in LiF-NaF-KF (46.5–11.5–42 mol%) media at 500 °C. In this salt, the reference redox system generated by coulometry at applied current is KF/K, metallic potassium being electrodeposited on a tungsten wire electrode. The validation of the DRE response and the experimental optimization parameters for DRE generation were realized by following the NiF 2 /Ni redox potential evolution as a function of NiF 2 concentration in the fused salt. The current value applied for DRE generation was optimized. It depends on the amount of metallic cations contained in the fused salt and which can be electrochemically reduced simultaneously during the DRE generation. The current corresponding to the DRE generation has to be 4 times greater than the current corresponding to the reduction of the other elements.

  14. Interaction of hyperthermia and photoradiation therapy

    International Nuclear Information System (INIS)

    Waldow, S.M.; Dougherty, T.J.

    1984-01-01

    Local microwave hyperthermia (2450 MHz) was applied to auxillary implants of the SMT-F mammary carcinoma in mice in combination with photoradiation therapy (PRT) in an attempt to determine if the two modalities interact. When 40.5 0 C was applied for 30 min immediately prior to or immediately following PRT enhancement of tumor response over that of PRT alone was seen as judged by lack of tumor regrowth (35 days or longer after treatment). A temperature of 41.5 0 C applied for 30 min immediately following the 30-min PRT treatment produced a result slightly greater than that seen at 40.5 0 C. When a temperature of 44.5 0 C for 30 min was applied immediately following PRT, a substantial enhancement of tumor control at 35 days post-treatment was found. These results suggest that tumor response to PRT is enhanced by both a sublethal hyperthermic treatment (40.5 0 C, 41.5 0 C) and a moderately lethal heat treatment (44.5 0 C) given for a short duration, when applied immediately before or after photoradiation

  15. Effect of hyperthermia on radiation damage and its repair in Tribolium confusum

    International Nuclear Information System (INIS)

    Lai, P.K.

    1977-01-01

    A series of temperature tolerance curves from 43.5 0 C to 46.0 0 C in 0.5 0 C increment were determined. Two non-lethal hyperthermia schemes, i.e., 45.0 0 C for 2 hr and 43.0 0 C for 2 hr were chosen to examine the sensitizing effect of heat on lethality produced by radiation in flour beetles. When hyperthermia was applied either immediately before or after irradiation, the sensitizing effect of hyperthermia was indicated by the shifting of the regression line of survival in probits on dose to the left of that of the control. The sensitizing effect as measured by decreased LD 50 did not reveal any definite trend related to the order of application of the two modalities in immediate sequence. The effect of hyperthermia was more dramatic in dose-fractionation experiments. Flour beetles exhibited typical Elkind kinetics of split-dose repair and recovery, and the amount of the sparing effect of dose-fractionation (sdf) was influenced by interfraction temperature. Both interfraction hypothermia (i.e., less than or equal to 10 0 C) and interfraction hyperthermia (i.e., > 42.0 0 C) completely suppress sdf. However, the mechanism involved in the suppression of sdf by hypothermia was different than that by hyperthermia. In the former, the suppression of sdf was reversible immediately upon return to the normal incubation temperature of 30 0 C; in the latter, the suppression of sdf was protracted and the reversibility of sdf depended on the severity of the hyperthermia treatment. Hyperthermia of 43.0 0 C for 2 hr, applied either immediately before or after the first radiation dose, suppressed sdf for 6-10 hr, and then sdf reappeared slowly, so that the final level of survival was slightly less than that of the comparable groups maintained at 30 0 C. With the more severe hyperthermia treatment of 45.0 0 C for 2 hr, sdf was suppressed for almost 36 hr after return to 30 0 C although there were some slight surges in survival

  16. Preoperative radiochemotherapy in locally advanced or recurrent rectal cancer: regional radiofrequency hyperthermia correlates with clinical parameters

    International Nuclear Information System (INIS)

    Rau, B.; Wust, P.; Tilly, W.; Gellermann, J.; Harder, C.; Riess, H.; Budach, V.; Felix, R.; Schlag, P.M.

    2000-01-01

    Purpose: Preoperative radiochemotherapy (RCT) is a widely used means of treatment for patients suffering from primary, locally advanced, or recurrent rectal cancer. We evaluated the efficacy of treatment due to additional application of regional hyperthermia (HRCT) to this conventional therapy regime in a Phase II study, employing the annular phased-array system BSD-2000 (SIGMA-60 applicator). The clinical results of the trial were encouraging. We investigated the relationship between a variety of thermal and clinical parameters in order to assess the adequacy of thermometry, the effectiveness of hyperthermia therapy, and its potential contribution to clinical endpoints. Methods and Materials: A preoperative combination of radiotherapy (1.8 Gy for 5 days a week, total dose 45 Gy applied over 5 weeks) and chemotherapy (low-dose 5-fluorouracil [5-FU] plus leucovorin in the first and fourth week) was administered to 37 patients with primary rectal cancer (PRC) and 18 patients with recurrent rectal cancer (RRC). Regional hyperthermia (RHT) was applied once a week prior to the daily irradiation fraction of 1.8 Gy. Temperatures were registered along rectal catheters using Bowman thermistors. Measurement points related to the tumor were specified after estimating the section of the catheter in near contact with the tumor. Three patients with local recurrence after abdominoperineal resection, had their catheters positioned transgluteally under CT guidance, where the section of the catheter related to the tumor was estimated from the CT scans. Index temperatures (especially T max , T 90 ) averaged over time, cumulative minutes (cum min) (here for T 90 > reference temperature 40.5 deg. C), and equivalent minutes (equ min) (with respect to 43 deg. C) were derived from repetitive temperature-position scans (5- to 10-min intervals) utilizing software specially developed for this purpose on a PC platform. Using the statistical software package SPSS a careful analysis was

  17. Magnetic nanowires and hyperthermia: How geometry and material affect heat production efficiency

    KAUST Repository

    Contreras, Maria F.

    2015-05-01

    Magnetic hyperthermia, which refers to the production of heat by magnetic nanostructures under an alternating magnetic field (AMF), has been previously investigated with superparamagnetic nanobeads as a cancer therapy method. Magnetic nanowires (NWs) used in hyperthermia can be very promising, as it has been shown that they have a larger magnetic moment per unit of volume compared to the nanobeads. Moreover, Fe NWs proved to have a higher heating efficiency compared to Fe nanobeads, when exposed to an AMF at the same concentration [1].

  18. Role of regional radiofrequency hyperthermia after hepatic artery block in the normal pit liver

    International Nuclear Information System (INIS)

    Luo Jingwei; Xu Guozhen; Xiong Jinghong; Liu Xiaoyun; Wang Weihu; Li Yexiong

    2003-01-01

    Objective: To study the temperature difference, tolerated high temperature, pathological changes between normal and blocked hepatic artery in radiofrequency hyperthermia for pig liver. Methods: Mature pig was used with iodine blocked right hepatic artery. Heat of the whole liver was given for 1 hour by SR-1000 radiofrequency hyperthermia with four thermocouple probes to measure the temperature of the right hepatic artery, right and left normal liver and rectum. Results: Temperature of blocked right liver increased by 10.2 degree C from 39.1 degree C to 49.3 degree C as compared with the left liver of which the temperature rose by 6.8 degree C from 39.7 degree C to 46.5 degree C but the temperature of right hepatic artery and rectum rose only by 3.3 degree C, 3.2 degree C respectively. After sacrificing the pig one week later, on lobe exploration, severe necrosis was observed in the right lobe but the left lobe was normal with a clear demarcation between the two lobes. Conclusions: Hepatic arterial iodine embolization potentiates radiofrequency hyperthermia in the liver. Liver with blocked artery showed conspicuous necrosis but liver with normal un-blocked artery was able to tolerate 46.5 degree C. This provides some evidence for the combination of regional hyperthermia and hepatic artery block in the treatment of advanced liver cancer

  19. Fish can show emotional fever: stress-induced hyperthermia in zebrafish.

    Science.gov (United States)

    Rey, Sonia; Huntingford, Felicity A; Boltaña, Sebastian; Vargas, Reynaldo; Knowles, Toby G; Mackenzie, Simon

    2015-11-22

    Whether fishes are sentient beings remains an unresolved and controversial question. Among characteristics thought to reflect a low level of sentience in fishes is an inability to show stress-induced hyperthermia (SIH), a transient rise in body temperature shown in response to a variety of stressors. This is a real fever response, so is often referred to as 'emotional fever'. It has been suggested that the capacity for emotional fever evolved only in amniotes (mammals, birds and reptiles), in association with the evolution of consciousness in these groups. According to this view, lack of emotional fever in fishes reflects a lack of consciousness. We report here on a study in which six zebrafish groups with access to a temperature gradient were either left as undisturbed controls or subjected to a short period of confinement. The results were striking: compared to controls, stressed zebrafish spent significantly more time at higher temperatures, achieving an estimated rise in body temperature of about 2-4°C. Thus, zebrafish clearly have the capacity to show emotional fever. While the link between emotion and consciousness is still debated, this finding removes a key argument for lack of consciousness in fishes. © 2015 The Authors.

  20. Effect of the radiation in the reference temperature T0 in ferritic steel

    International Nuclear Information System (INIS)

    Villanueva O, A.; Gachuz M, M.E.

    2004-01-01

    The present work studies the effect that produces the irradiation in ferritic steels (AISI 8620) on the reference temperature (T 0 ) that characterizes the tenacity to the fractures (K JC ) of these materials obtaining this way a characteristic curve (Master Curve) of this steel. The approach of the 'Master curve' is based on the Astm E-1921. Following this standard the methodology of a sub size settled down in Charpy type test tubes. Due to this type of steels is used mainly in pressure vessels of the reactor in Nuclear Power plants, the fracture tenacity gives the rule at the moment for the verification of structural integrity of the pressure vessel of the reactor. (Author)

  1. nNOS inhibitors attenuate methamphetamine-induced dopaminergic neurotoxicity but not hyperthermia in mice.

    Science.gov (United States)

    Itzhak, Y; Martin, J L; Ail, S F

    2000-09-11

    Methamphetamine (METH)-induced dopaminergic neurotoxicity is associated with hyperthermia. We investigated the effect of several neuronal nitric oxide synthase (nNOS) inhibitors on METH-induced hyperthermia and striatal dopaminergic neurotoxicity. Administration of METH (5 mg/kg; q. 3 h x 3) to Swiss Webster mice produced marked hyperthermia and 50-60% depletion of striatal dopaminergic markers 72 h after METH administration. Pretreatment with the nNOS inhibitors S-methylthiocitrulline (SMTC; 10 mg/kg) or 3-bromo-7-nitroindazole (3-Br-7-NI; 20 mg/kg) before each METH injection did not affect the persistent hyperthermia produced by METH, but afforded protection against the depletion of dopaminergic markers. A low dose (25 mg/kg) of the nNOS inhibitor 7-nitroindazole (7-NI) did not affect METH-induced hyperthermia, but a high dose (50 mg/kg) produced significant hypothermia. These findings indicate that low dose of selective nNOS inhibitors protect against METH-induced neurotoxicity with no effect on body temperature and support the hypothesis that nitric oxide (NO) and peroxynitrite have a major role in METH-induced dopaminergic neurotoxicity.

  2. Infrared fibers for radiometer thermometry in hypothermia and hyperthermia treatment

    International Nuclear Information System (INIS)

    Katzir, A.; Bowman, H.F.; Asfour, Y.; Zur, A.; Valeri, C.R.

    1989-01-01

    Hypothermia is a condition which results from prolonged exposure to a cold environment. Rapid and efficient heating is needed to rewarm the patient from 32-35 degrees C to normal body temperature. Hyperthermia in cancer treatment involves heating malignant tumors to 42.5-43.0 degrees C for an extended period (e.g., 30 min) in an attempt to obtain remission. Microwave or radio frequency heating is often used for rewarming in hypothermia or for temperature elevation in hyperthermia treatment. One severe problem with such heating is the accurate measurement and control of temperature in the presence of a strong electromagnetic field. For this purpose, we have developed a fiberoptic radiometer system which is based on a nonmetallic, infrared fiber probe, which can operate either in contact or noncontact mode. In preliminary investigations, the radiometer worked well in a strong microwave or radiofrequency field, with an accuracy of +/- 0.5 degrees C. This fiberoptic thermometer was used to control the surface temperature of objects within +/- 2 degrees C

  3. Thermometry of hot spot using NMR for hyperthermia

    International Nuclear Information System (INIS)

    Amemiya, Yoshifumi; Kamimura, Yoshitsugu

    1983-01-01

    Lately noticed hyperthermia in cancer therapy requires non-invasive measurement of the temperature at the warmed site in the deep portion of human body. Nuclear magnetic relaxation time of NMR is also usable for cancer diagnosis. For coordination of these two techniques, it was judged suitable to measure temperature by NMR so that cancer diagnosis and treatment and evaluation of therapeutic effect might be incorporated into one system. This report dealt with concrete procedures of measuring the temperature of deep portions by NMR. Computations revealed that the coefficient of temperature of the thermal equilibrium magnetization was useful, that magnetic field focusing was the most effective imaging technique and that temperature rise in areas about 2 cm in radius could be measured without large errors. (Chiba, N.)

  4. Standard test method for determination of reference temperature, to, for ferritic steels in the transition range

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This test method covers the determination of a reference temperature, To, which characterizes the fracture toughness of ferritic steels that experience onset of cleavage cracking at elastic, or elastic-plastic KJc instabilities, or both. The specific types of ferritic steels (3.2.1) covered are those with yield strengths ranging from 275 to 825 MPa (40 to 120 ksi) and weld metals, after stress-relief annealing, that have 10 % or less strength mismatch relative to that of the base metal. 1.2 The specimens covered are fatigue precracked single-edge notched bend bars, SE(B), and standard or disk-shaped compact tension specimens, C(T) or DC(T). A range of specimen sizes with proportional dimensions is recommended. The dimension on which the proportionality is based is specimen thickness. 1.3 Median KJc values tend to vary with the specimen type at a given test temperature, presumably due to constraint differences among the allowable test specimens in 1.2. The degree of KJc variability among specimen types i...

  5. Simplified Reference Electrode for Electrorefining of Spent Nuclear Fuel in High Temperature Molten Salt

    International Nuclear Information System (INIS)

    Kim Davies; Shelly X Li

    2007-01-01

    Pyrochemical processing plays an important role in development of proliferation-resistant nuclear fuel cycles. At the Idaho National Laboratory (INL), a pyrochemical process has been implemented for the treatment of spent fuel from the Experimental Breeder Reactor II (EBR-II) in the last decade. Electrorefining in a high temperature molten salt is considered a signature or central technology in pyroprocessing fuel cycles. Separation of actinides from fission products is being demonstrated by electrorefining the spent fuel in a molten UCl3-LiCl-KCl electrolyte in two engineering scale electrorefiners (ERs). The electrorefining process is current controlled. The reference electrode provides process information through monitoring of the voltage difference between the reference and the anode and cathode electrodes. This information is essential for monitoring the reactions occurring at the electrodes, investigating separation efficiency, controlling the process rate, and determining the process end-point. The original reference electrode has provided good life expectancy and signal stability, but is not easily replaceable. The reference electrode used a vycor-glass ion-permeable membrane containing a high purity silver wire with one end positioned in ∼2 grams of LiCl/KCl salt electrolyte with a low concentration (∼1%) AgCl. It was, however, a complex assembly requiring specialized skill and talent to fabricate. The construction involved multiple small pieces, glass joints, ceramic to glass joints, and ceramic to metal joints all assembled in a high purity inert gas environment. As original electrodes reached end-of-life it was uncertain if the skills and knowledge were readily available to successfully fabricate replacements. Experimental work has been conducted to identify a simpler electrode design while retaining the needed long life and signal stability. This improved design, based on an ion-permeable membrane of mullite has been completed. Use of the silver

  6. Simplified Reference Electrode for Electrorefining of Spent Nuclear Fuel in High Temperature Molten Salt

    Energy Technology Data Exchange (ETDEWEB)

    Kim Davies; Shelly X Li

    2007-09-01

    Pyrochemical processing plays an important role in development of proliferation- resistant nuclear fuel cycles. At the Idaho National Laboratory (INL), a pyrochemical process has been implemented for the treatment of spent fuel from the Experimental Breeder Reactor II (EBR-II) in the last decade. Electrorefining in a high temperature molten salt is considered a signature or central technology in pyroprocessing fuel cycles. Separation of actinides from fission products is being demonstrated by electrorefining the spent fuel in a molten UCl3-LiCl-KCl electrolyte in two engineering scale electrorefiners (ERs). The electrorefining process is current controlled. The reference electrode provides process information through monitoring of the voltage difference between the reference and the anode and cathode electrodes. This information is essential for monitoring the reactions occurring at the electrodes, investigating separation efficiency, controlling the process rate, and determining the process end-point. The original reference electrode has provided good life expectancy and signal stability, but is not easily replaceable. The reference electrode used a vycor-glass ion-permeable membrane containing a high purity silver wire with one end positioned in ~2 grams of LiCl/KCl salt electrolyte with a low concentration (~1%) AgCl. It was, however, a complex assembly requiring specialized skill and talent to fabricate. The construction involved multiple small pieces, glass joints, ceramic to glass joints, and ceramic to metal joints all assembled in a high purity inert gas environment. As original electrodes reached end-of-life it was uncertain if the skills and knowledge were readily available to successfully fabricate replacements. Experimental work has been conducted to identify a simpler electrode design while retaining the needed long life and signal stability. This improved design, based on an ion-permeable membrane of mullite has been completed. Use of the silver wire

  7. The case for SAR as the major component of a hyperthermia treatment unit

    International Nuclear Information System (INIS)

    Scott, R.S.

    1985-01-01

    A major problem facing clinical hyperthermia is the lack of a useful unit of treatment. Most attempts at a treatment unit have utilized some function of temperature and time. Having accepted the validity of such a hypothetical units, one is faced with the formidable problem of obtaining a three dimensional temperature profile so that thermal dose can be determined. A corollary is the desirability of obtaining uniform temperature in the treatment volume. Various studies suggest that a uniform SAR is a more desirable goal when radiotherapy is to be used in combination with hyperthermia. The synergy between radiation and hyperthermia is maximized in low pH regions of tumor which are presumably also hypoxic. These regions are poorly perfused, likely to heat readily, and are resistant to the cytotoxic effects of radiation alone. On the other hand, well perfused regions of tumor are likely sensitive to radiation, and benefit less from the combination treatment. Other studies have definitely shown that tissue temperatures in the range normally associated with desirable hyperthermia treatment result in severe vascular damage. This damage could be expected to unnecessarily compromise the effectiveness of radiotherapy. Models in the literature can be combined to verify these observations

  8. A multipoint feedback control system for scanned focussed ultrasound hyperthermia

    International Nuclear Information System (INIS)

    Johnson, C.; Kress, R.; Roemer, R.; Hynynen, K.

    1987-01-01

    A multipoint feedback control system has been developed and tested for use with a scanned focussed ultrasound hyperthermia system. Extensive in-vivo tests (using a perfused organ model) have been made to evaluate the basic performance characteristics of the feedback control scheme for control of temperature in perfused media. The results of these tests are presented and compared with the predictions of a simulation routine. The control scheme was also tested in vivo using dogs' thighs and kidneys. Thigh experiments show the control scheme responds well to the affects of vasodilation and is able to maintain the targeted temperatures. In kidney experiments, where the rate of perfusion was controllable, the power adjusting algorithm successfully maintained uniform temperature distributions across regions of varying rates of perfusion. As a conclusion, the results show that this multipoint feedback controller scheme induces uniform temperature distributions when used with scanned focussed ultrasound systems

  9. Hyperthermia system working in combination with an MR imaging unit

    International Nuclear Information System (INIS)

    LeBihan, D.J.; Delannoy, J.; Levin, R.L.; Hoult, D.I.

    1988-01-01

    The authors propose a hyperthermia device to be used for temperature monitoring. It consists of a modified miniannular phased array (MAPA) radio-frequency applicator designed for limb tumor treatment that works in combination with a whole-body MR imaging unit operating at 21 MHz. Highly accurate (0.5 0 c/0.8 cm 2 ) temperature images are obtained noninvasively throughout the heated volume from MR images of molecular diffusion, the relation of which with temperature is well known. The MAPA, electrically modified to be compatible with MR imagers, can be centered inside the MR head coil. The combined system was tested on a phantom in which the temperature distribution was confirmed by miniature thermocouples

  10. Temperature- and supply voltage-independent time references for wireless sensor networks

    CERN Document Server

    De Smedt, Valentijn; Dehaene, Wim

    2015-01-01

    This book investigates the possible circuit solutions to overcome the temperature- and supply voltage-sensitivity of fully-integrated time references for ultra-low-power communication in wireless sensor networks. The authors provide an elaborate theoretical introduction and literature study to enable full understanding of the design challenges and shortcomings of current oscillator implementations.  Furthermore, a closer look to the short-term as well as the long-term frequency stability of integrated oscillators is taken. Next, a design strategy is developed and applied to 5 different oscillator topologies and 1 sensor interface.All 6 implementations are subject to an elaborate study of frequency stability, phase noise, and power consumption. In the final chapter all blocks are compared to the state of the art. The main goals of this book are: • to provide a comprehensive overview of timing issues and solutions in wireless sensor networks; • to gain understanding of all underlying mechanisms by starti...

  11. Effects of hyperthermia and radiation on mouse testis stem cells

    International Nuclear Information System (INIS)

    Reid, B.O.; Mason, K.A.; Withers, H.R.; West, J.

    1981-01-01

    The response of mouse testis stem cells to hyperthermia and combined hyperthermia-radiation treatments was assayed by spermatogenic colony regrowth, sperm head counts, testis weight loss, and fertility. With the use of spermatogenic colony assay, thermal enhancement ratios at an isosurvival level of 0.1 were 1.27 at 41 degrees, 1.80 at 42 degrees, and 3.97 at 43 degrees for testes exposed to heat for 30 min prior to irradiation. Sperm head counts were reduced by heat alone from a surviving fraction of 0.58 at 41 degrees to 0.003 at 42.5-43.5 degrees. Curves for sperm head survival measured 56 days after the testes had been heated for 30 min prior to irradiation were biphasic and showed a progressive downward displacement to lower survival with increasing temperature. The 41, 42, and 43 degrees curves were displaced downward by factors of 2, 58, and 175, respectively. The proportion of animals remaining sterile after 30 min of heat (41-43 degrees) and the median sterility period in days increased with increasing temperature. The minimum sperm count necessary to regain fertility was 13% of the normal mouse level

  12. Microwave hyperthermia enhancement of methotrexate absorption in rat brains

    International Nuclear Information System (INIS)

    Lin, J.C.; Yuen, M.K.; Jung, D.T.

    1987-01-01

    The author studied enhanced absorption of methotrexate (MTX) in brains of male Wistar (10 weeks old, 500g) subjected to microwave hyperthermia. The rat was anesthetized using 40 mg/kg of sodium pentobarbital, IP and was placed in a stereotaxic head holder. Microwave energy (2450 MHz, 2.6 W/cm/sup 2/, CW) were applied directly to the left side of the rat's head by a coaxial applicator for 20 min. The body temperature was kept at 37.8 0 C. The brain temperature recorded in a similar group of animals using a Vitek probe was about 45 0 C. Three different MTX dosages, 50, 100 and 200 mg/kg, were injected intravenously immediately following microwave irradiation into three groups of rats in 1.5, 3 and 6 min., respectively. MTX was allowed to circulate for five min. before brains were removed for analysis. Standard HPLC procedures were applied to samples from anterior and posterior left hemisphere of the cerebrum, and the cerebellum. Samples from the right hemisphere were used for controls. The average absorption at the posterior left hemisphere was found to be 2.4, 9.6 and 12.4μg of MTX/g of brain tissue for 50, 100 and 200 mg/kg, respectively. These results indicate that MTX absorption is significantly increased in rat brains subjected to microwave hyperthermia treatment

  13. Deep RF-hyperthermia: an effective treatment of advanced gliomas

    International Nuclear Information System (INIS)

    Sahinbas, H.; Groenemeyer, D.H.W.

    2005-01-01

    Full text: Contrary to the enormous efforts, results of conventional treatments of high-grade malignant gliomas are unsatisfactory. The prognosis of that tumor type is poor, its overall median survival time (MST) less than a year. Most of the cases are inoperable or only partially resectable, and their response to the various chemotherapies and/or radiotherapy is poor. The chemo-therapies which are successful for other locations often fail due to the effective brain-blood barrier (BBB). Probably the modification of the BBB by electromagnetic fields together with the direct electromagnetic-field heating are the main factors for the success of electro-hyperthermia. Primary aim of this study was to present the therapy tolerance for patients of electro-hyperthermia (EHY) for advanced malignant gliomas and as main intention to show the increase of the median survival time (MST). Our study was performed between 2000 - 2004; for patients with inoperable, partially resected or recurrent gliomas (WHO grade III and IV) with progression after radio- and/or chemotherapy and a Karnofsky Performance Score ≤30-40 %. 105 pts were involved in this study: 38 astrocytoma pts, 56 glioblastoma pts and 12 pts with other brain malignancies. All patients were heavily and unsatisfactory pretreated. EHY was applied over 4 weeks, 3 times a week over 1 hour in average by 100 Watt, as mono- or combined therapy (chemotherapy, irradiation therapy). The set of patients as well as the frequency of EHY was well documented for future evaluations. The historic reference of the MST from the first diagnosis for gliomas grade III and IV in our institute is 11.42 months (range 1-62), which is in good agreement with the relevant literature. The median survival time (MST) in our institute with EHY increases to 44.2 m, 23.2 m and 61.0 m for astrocytoma, glioblastoma and other brain malignancies, respectively. The therapy results were controlled by MRI images. EHY is a feasible treatment for advanced

  14. Effects of hyperthermia on repair of radiation-induced DNA strand breaks

    International Nuclear Information System (INIS)

    Mills, M.D.; Meyn, R.E.

    1981-01-01

    Previous reports have suggested a relationship between the heat-induced changes in nucleoprotein and the hyperthermic enhancement of radiation sensitivity. In an effort to further understand these relationships, we measured the level of initial DNA strand break damage and the DNA strand break rejoining kinetics in Chinese hamster ovary cells following combined hyperthermia and ionizing radiation treatments. The amount of protein associated with DNA measured as the ratio of [ 3 H)leucine to [ 14 C]thymidine was also compared in chromatin isolated from both heated and unheated cells. The results of these experiments show that the initial level of radiation-induced DNA strand breaks is significantly enhanced by a prior hyperthermia treatment of 43 0 C for 30 min. Treatments at higher temperatures and longer treatments at the same temperature magnified this effect. Hyperthermia was also shown to cause a substantial inhibition of the DNA strand break rejoining after irradiation. Both the initial level of DNA damage and the rejoining kinetics recovered to normal levels with incubation at 37 0 C between the hyperthermia and radiation treatments. Recovery of these parameters coincided with the return of the amount of protein associated with DNA to normal values, further suggesting a relationship between the changes in nucleoprotein and the hyperthermic enhancement of radiation sensivivity

  15. Temperature-field measurements of a premixed butane/air circular impinging-flame using reference-beam interferometry

    International Nuclear Information System (INIS)

    Qi, J.A.; Leung, C.W.; Wong, W.O.; Probert, S.D.

    2006-01-01

    Reference-beam interferometry (RBI) was applied to study the axisymmetric temperature fields of a small-scale, low Reynolds-number, low-pressure and fuel-rich premixed butane/air circular-flame jet, when it was impinging vertically upwards onto a horizontal copper plate. By maintaining a Reynolds number, Re, of 500 and an equivalence ratio, φ, of 1.8, interferograms of the impinging-flame jet were obtained for various nozzle-to-plate-distances. Temperature fields of the flame were then determined using the inverse Abel transformation from the obtained interferograms. Temperatures at several locations were measured experimentally with a T-type thermocouple: they were used as a reference to help in the determination as well as the validation. In the present study, a non-contact method has been successfully developed to measure the temperature fields of a circular impinging gas-fired flame jet

  16. A numerical study on dual-phase-lag model of bio-heat transfer during hyperthermia treatment.

    Science.gov (United States)

    Kumar, P; Kumar, Dinesh; Rai, K N

    2015-01-01

    The success of hyperthermia in the treatment of cancer depends on the precise prediction and control of temperature. It was absolutely a necessity for hyperthermia treatment planning to understand the temperature distribution within living biological tissues. In this paper, dual-phase-lag model of bio-heat transfer has been studied using Gaussian distribution source term under most generalized boundary condition during hyperthermia treatment. An approximate analytical solution of the present problem has been done by Finite element wavelet Galerkin method which uses Legendre wavelet as a basis function. Multi-resolution analysis of Legendre wavelet in the present case localizes small scale variations of solution and fast switching of functional bases. The whole analysis is presented in dimensionless form. The dual-phase-lag model of bio-heat transfer has compared with Pennes and Thermal wave model of bio-heat transfer and it has been found that large differences in the temperature at the hyperthermia position and time to achieve the hyperthermia temperature exist, when we increase the value of τT. Particular cases when surface subjected to boundary condition of 1st, 2nd and 3rd kind are discussed in detail. The use of dual-phase-lag model of bio-heat transfer and finite element wavelet Galerkin method as a solution method helps in precise prediction of temperature. Gaussian distribution source term helps in control of temperature during hyperthermia treatment. So, it makes this study more useful for clinical applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Measurement of the high-temperature Seebeck coefficient of thin films by means of an epitaxially regrown thermometric reference material.

    Science.gov (United States)

    Ramu, Ashok T; Mages, Phillip; Zhang, Chong; Imamura, Jeffrey T; Bowers, John E

    2012-09-01

    The Seebeck coefficient of a typical thermoelectric material, silicon-doped InGaAs lattice-matched to InP, is measured over a temperature range from 300 K to 550 K. By depositing and patterning a thermometric reference bar of silicon-doped InP adjacent to a bar of the material under test, temperature differences are measured directly. This is in contrast to conventional two-thermocouple techniques that subtract two large temperatures to yield a small temperature difference, a procedure prone to errors. The proposed technique retains the simple instrumentation of two-thermocouple techniques while eliminating the critical dependence of the latter on good thermal contact. The repeatability of the proposed technique is demonstrated to be ±2.6% over three temperature sweeps, while the repeatability of two-thermocouple measurements is about ±5%. The improved repeatability is significant for reliable reporting of the ZT figure of merit, which is proportional to the square of the Seebeck coefficient. The accuracy of the proposed technique depends on the accuracy with which the high-temperature Seebeck coefficient of the reference material may be computed or measured. In this work, the Seebeck coefficient of the reference material, n+ InP, is computed by rigorous solution of the Boltzmann transport equation. The accuracy and repeatability of the proposed technique can be systematically improved by scaling, and the method is easily extensible to other material systems currently being investigated for high thermoelectric energy conversion efficiency.

  18. ADPRT inhibitors and hyperthermia as radiosensitizers

    International Nuclear Information System (INIS)

    Jonsson, G.G.

    1985-01-01

    Hyperthermia given in combination with gamma radiation has given considerable improvement in the therapeutic results for treatment of malignant tumors. The mechanism behind the hyperthermia effect is probably operative at the tissue level as well as at the molecular level. The metabolism of NAD + in relation to the activity of the chromosomal enzyme ADP-ribosyl transferase (ADPRT) has been studied as a possible molecular mechanism for this effect. The ADPRT activity was measured after radiosensitization with both hyperthermia and nicotinamide, which is a potent inhibitor of ADPRT. The results indicate that hyperthermia can improve the effect of radiotherapy by reducing the supply of NAD + , which is a co-substrate for ADPRT, while nicotinamide functions as a radiosensitizing agent by direct inhibition of the enzyme. The hypothesis is discussed in the thesis where inhibition of ADPRT might increase the radiosensitivity because the radiation-induced DNA damage can not be repaired with normal efficiency. The function of nicotinamide as a radiosensitizer was verified by studies on C3H mice with transplanted spontaneous mammary tumors. Because nicotinamide is not toxic, it seems quite attractive to test this vitamin as a radiosensitizing agent against human tumors. (251 refs.) (author)

  19. Reference test methods for total water in lint cotton by Karl Fischer Titration and low temperature distillation

    Science.gov (United States)

    In a study of comparability of total water contents (%) of conditioned cottons by Karl Fischer Titration (KFT) and Low Temperature Distillation (LTD) reference methods, we demonstrated a match of averaged results based on a large number of replications and weighing the test specimens at the same tim...

  20. Intestinal cell proliferation following hyperthermia-radiation combinations

    International Nuclear Information System (INIS)

    Burholt, D.R.; Wilkinson, D.A.; Shrivastava, P.N.

    1987-01-01

    The present work is an investigation of the extent to which hyperthermia enhances x-ray induced inhibition of intestinal epithelial cell proliferation in mice. Hyperthermia was achieved by whole body immersion of anesthetized ice in a temperature controlled water bath (+-0.1 0 C). Post-treatment proliferative activity was monitored by determining the incorporation of /sup 3/H-TdR into intestinal crypt cells and by the counting of epithelial cell mitotic figures. Initial levels of cell kill were assessed by the microcolony crypt survival technique. All heat treatments were 41.5 0 C for 0.5h. Heat alone reduced the /sup 3/H-TdR incorporation to 50% of the control value by 2h post-treatment. This was followed by a return to control value by 10h and a slight hyperplasia at 24h. Heat either immediately before or after 2Gy abdominal field x-irradiation produced a prolonged period of depressed cell proliferation: /sup 3/H-TdR incorporation remained below control value for the first 24h. As the heat and radiation were separated in time from each other (up to 4h) the interaction between the two decreased. The development of thermotolerance was observed following the second and third treatment during either a heat-only or a heat-radiation multifraction treatments schedule with the treatment spaced 24h apart

  1. [Malignant hyperthermia in a black child. A case report].

    Science.gov (United States)

    Hugo, J M; Ungerer, M J; Erasmus, F R; du Toit, P W; Muller, F O; van Velden, D J

    1978-05-20

    A case of malignant hyperthermia in a Black boy is presented. He developed this condition during repair of a cleft palate, with halothane as the triggering agent. The importance of the high incidence of malignant hyperthermia in patients with certain musculoskeletal abnormalities is stressed. Despite a cool and well air-conditioned theatre, the patient's temperature was 41 degree C when the condition was suspected. At that stage general muscle rigidity was present. The patient was successfully treated with procainamide, sodium bicarbonate and hydrocortisone; surface cooling (with ice packs) was instituted and the stomach was washed out with ice-cold Ringer's solution. Over a period of 14 days serum creatine phosphokinase values decreased from 630 IU (on the day of the incident) to 12 IU. A muscle biopsy showed variation in muscle fibre size. Electron microscopical studies showed myofibrillar disruption and folding of the basement membrane. A modified version of Denborough's technique was used for the in vitro exposure of muscle strips to halothane and suxamethonium. Isometric contraction was measured and recorded. A severe contraction followed the exposure of muscle strips to halothane, which confirmed the diagnosis.

  2. Ferromagnetic nanoparticles for magnetic hyperthermia and thermoablation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kita, Eiji; Kayano, Takeru; Sato, Suguru; Minagawa, Makoto; Yanagihara, Hideto; Kishimoto, Mikio [Institute of Applied Physics, University of Tsukuba, Tsukuba 305-8573 (Japan); Oda, Tatsuya; Hashimoto, Shinji; Yamada, Keiichi; Ohkohchi, Nobuhiro [Department of Surgery, Advanced Biomedical Applications, Graduate School of Comprehensive Human Science, University of Tsukuba, Tsukuba 305-8575 (Japan); Mitsumata, Chiharu, E-mail: kita@bk.tsukuba.ac.j [Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan)

    2010-12-01

    The use of ferromagnetic nanoparticles for hyperthermia and thermoablation therapies has shown great promise in the field of nanobiomedicine. Even local hyperthermia offers numerous advantages as a novel cancer therapy; however, it requires a remarkably high heating power of more than 1 kW g{sup -1} for heat agents. As a candidate for high heat generation, we focus on ferromagnetic nanoparticles and compare their physical properties with those of superparamagnetic substances. Numerical simulations for ideal single-domain ferromagnetic nanoparticles with cubic and uniaxial magnetic symmetries were carried out and MH curves together with minor loops were obtained. From the simulation, the efficient use of an alternating magnetic field (AMF) having a limited amplitude was discussed. Co-ferrite nanoparticles with various magnitudes of coercive force were produced by co-precipitation and a hydrothermal process. A maximum specific loss power of 420 W g{sup -1} was obtained using an AMF at 117 kHz with H{sub 0} = 51.4 kA m{sup -1} (640 Oe). The relaxation behaviour in the ferromagnetic state below the superparamagnetic blocking temperature was examined by Moessbauer spectroscopy.

  3. Production of lesions in rabbit spinal cord with microwave hyperthermia

    International Nuclear Information System (INIS)

    Sutton, C.H.; Popovic, P.

    1984-01-01

    The use of a variety of injury models in different species to produce spinal cord lesions by trauma or ischemia has often given rise to conflicting or inconclusive data. A new model has been developed in rabbits. Spinal cord lesions were produced in selected spinal cord segments of male New Zealand white rabbits by non-invasive irradiation with microwaves in the near field at 915 MHz. Graded injuries of predictable severity can be produced by the non-invasive induction of moderate hyperthermia in the thoracic spinal cord at precise dosage levels of temperature elevation and duration. Histological changes in microwave-induced hyperthermia closely parallel those seen in traumatic lesions of the human spinal cord, as well as those produced in animals with the classical weight-drop method of Allen. In addition to grading the spinal cord lesions with respect to residual neurological function, dose-response observations made with somatosensory evoked responses, blood-spinal cord barrier tracers, and neurohistological and enzyme histochemical preparations, suggest that it will be possible to use this approach to develop a standardized, calibrated model in rabbits to evaluate the efficacy of new therapeutic modalities for the treatment of spinal cord injury

  4. An internal reference model-based PRF temperature mapping method with Cramer-Rao lower bound noise performance analysis.

    Science.gov (United States)

    Li, Cheng; Pan, Xinyi; Ying, Kui; Zhang, Qiang; An, Jing; Weng, Dehe; Qin, Wen; Li, Kuncheng

    2009-11-01

    The conventional phase difference method for MR thermometry suffers from disturbances caused by the presence of lipid protons, motion-induced error, and field drift. A signal model is presented with multi-echo gradient echo (GRE) sequence using a fat signal as an internal reference to overcome these problems. The internal reference signal model is fit to the water and fat signals by the extended Prony algorithm and the Levenberg-Marquardt algorithm to estimate the chemical shifts between water and fat which contain temperature information. A noise analysis of the signal model was conducted using the Cramer-Rao lower bound to evaluate the noise performance of various algorithms, the effects of imaging parameters, and the influence of the water:fat signal ratio in a sample on the temperature estimate. Comparison of the calculated temperature map and thermocouple temperature measurements shows that the maximum temperature estimation error is 0.614 degrees C, with a standard deviation of 0.06 degrees C, confirming the feasibility of this model-based temperature mapping method. The influence of sample water:fat signal ratio on the accuracy of the temperature estimate is evaluated in a water-fat mixed phantom experiment with an optimal ratio of approximately 0.66:1. (c) 2009 Wiley-Liss, Inc.

  5. Controlled Hyperthermia with MRI-guided Focused Ultrasound

    DEFF Research Database (Denmark)

    Hokland, Steffen; Salomir, Rares; Pedersen, Michael

    Introduction: Hyperthermia is an appealing oncological treatment since the significant regions of hypoxia contained in most solid tumours are known to be sensitive to the cytotoxic effect of heat. However, due to the seemingly insurmountable technical difficulties associated with delivering thermal......-sensitive promoters and localized drug delivery using thermo-sensitive micro-carriers. Subjects Here we will present some of the recent advances in MRI-FUS, and their technical background. This will include: 1) Real-time MRI-thermometry. 2) FUS-technology. 3) Temporal and Spatial temperature control using MRI...... and penetration depth are governed by the wavelength. Hence for US it is possible to body non-invasively position sub-millimeter focal points in deep seated regions of the. Temperature Control: Most solid tumours cover volumes larger than that of the focal region. This problem may be reduced somewhat...

  6. Formula to estimate the thermal enhancement ratio of a single simultaneous hyperthermia and radiation treatment

    International Nuclear Information System (INIS)

    Overgaard, J.

    1984-01-01

    An experimental model composed of a C 3 H mammary carcinoma and its surrounding skin has been exposed to simultaneous radiation and hyperthermia given with different combinations of the heating time and temperature. Based on the thermal enhancement ratio (TER) values obtained in the temperature range 41.5 to 43.5 0 C, a linear relationship between TER and the heating time was achieved at each temperature. The slopes of the curves drawn at each temperature were found to have a log-linear relationship with the treatment temperature. With these relationships it was possible to make a formula expressing the TER as a function of treatment temperature and time. This formula gives a crude but probably acceptable estimate of the TER following a single simultaneous radiation and heat treatment. Although subject to several limitations, the formula represents an attempt to describe a heat dose concept for the radiosensitizing effect of hyperthermia. This may be useful to establish the tolerance level of a given radiation treatment when combined with hyperthermia. (Auth.)

  7. Re-irradiation and hyperthermia after surgery for recurrent breast cancer

    International Nuclear Information System (INIS)

    Linthorst, Marianne; Geel, Albert N. van; Baaijens, Margreet; Ameziane, Ali; Ghidey, Wendim; Rhoon, Gerard C. van; Zee, Jacoba van der

    2013-01-01

    Purpose: Evaluation of efficacy and side effects of combined re-irradiation and hyperthermia electively or for subclinical disease in the management of locoregional recurrent breast cancer. Methods and materials: Records of 198 patients with recurrent breast cancer treated with re-irradiation and hyperthermia from 1993 to 2010 were reviewed. Prior treatments included surgery (100%), radiotherapy (100%), chemotherapy (42%), and hormonal therapy (57%). Ninety-one patients were treated for microscopic residual disease following resection or systemic therapy and 107 patients were treated electively for areas at high risk for local recurrences. All patients were re-irradiated to 28–36 Gy (median 32) and treated with 3–8 hyperthermia treatments (mean 4.36). Forty percent of the patients received concurrent hormonal therapy. Patient and tumor characteristics predictive for actuarial local control (LC) and toxicity were studied in univariate and multivariate analysis. Results: The median follow-up was 42 months. Three and 5 year LC-rates were 83% and 78%. Mean of T90 (tenth percentile of temperature distribution), maximum and average temperatures were 39.8 °C, 43.6 °C, and 41.2 °C, respectively. Mean of the cumulative equivalent minutes (CEM43) at T90 was 4.58 min. Number of previous chemotherapy and surgical procedures were most predictive for LC. Cumulative incidence of grade 3 and 4 late toxicity at 5 years was 11.9%. The number of thermometry sensors and depth of treatment volume were associated with acute hyperthermia toxicity. Conclusions: The combination of re-irradiation and hyperthermia results in a high LC-rate with acceptable toxicity

  8. Similarities and differences in ablative and non-ablative iron oxide nanoparticle hyperthermia cancer treatment

    Science.gov (United States)

    Petryk, Alicia A.; Misra, Adwiteeya; Kastner, Elliot J.; Mazur, Courtney M.; Petryk, James D.; Hoopes, P. Jack

    2015-03-01

    The use of hyperthermia to treat cancer is well studied and has utilized numerous delivery techniques, including microwaves, radio frequency, focused ultrasound, induction heating, infrared radiation, warmed perfusion liquids (combined with chemotherapy), and recently, metallic nanoparticles (NP) activated by near infrared radiation (NIR) and alternating magnetic field (AMF) based platforms. It has been demonstrated by many research groups that ablative temperatures and cytotoxicity can be produced with locally NP-based hyperthermia. Such ablative NP techniques have demonstrated the potential for success. Much attention has also been given to the fact that NP may be administered systemically, resulting in a broader cancer therapy approach, a lower level of tumor NP content and a different type of NP cancer therapy (most likely in the adjuvant setting). To use NP based hyperthermia successfully as a cancer treatment, the technique and its goal must be understood and utilized in the appropriate clinical context. The parameters include, but are not limited to, NP access to the tumor (large vs. small quantity), cancer cell-specific targeting, drug carrying capacity, potential as an ionizing radiation sensitizer, and the material properties (magnetic characteristics, size and charge). In addition to their potential for cytotoxicity, the material properties of the NP must also be optimized for imaging, detection and direction. In this paper we will discuss the differences between, and potential applications for, ablative and non-ablative magnetic nanoparticle hyperthermia.

  9. Factors associated with high risk of marginal hyperthermia in elderly patients living in an institution.

    Science.gov (United States)

    Vassallo, M.; Gera, K. N.; Allen, S.

    1995-01-01

    The elderly, the very young, and the sick are known to be adversely affected by high environmental temperatures. In a retrospective open case-note review of 872 patients in a large institution during a hot summer we identified characteristics in the elderly that increase the risk of marginal hyperthermia. Women were more likely to be affected than men (25.6% vs 16.9%). We found an age-related increase in marginal hyperthermia, 15.7% of those below 60 years developed a hyperthermia compared to 18.9% in those between 70-79 years (non-significant), 28.3% in those between 80-89 years (p = 0.01) and 50% in those above 90 years (p bedridden group, p < 0.01, and 20.4% of the semi-dependent, p < 0.01, compared to 11.1% of the mobile group). These factors were more significant as predictors of risk than the diagnosis. Identifying high risk patients early and taking appropriate measures to avoid hyperthermia and dehydration is important to try to decrease mortality during heatwaves. PMID:7784280

  10. Interstitial hyperthermia using 8 MHz radiofrequency and stereotaxic brachytherapy for brain tumors

    International Nuclear Information System (INIS)

    Nishimura, Satoshi

    1990-01-01

    As a preliminary study of the interstitial hyperthermia combined with interstitial irradiation (brachytherapy) for the treatment of malignant brain tumors, we performed an experiment of interstitial hyperthermia of brain tissue of dogs. Nine afterloading tubes, four for needle electrodes and five for thermisters, were inserted in the brain tissue of dogs. Rise and stability of temperature were ascertained, and clinical safety was confirmed. Thereafter this combined therapy was applied on seven cases, in which three were malignant gliomas and four were metastatic tumors. Through the guide tubes, 192 Ir thin wires were implanted stereotaxically, and interstitial irradiation was carried out. After removal of 192 Ir wires, needle electrodes were inserted through the same tubes, and also a thermister was guided at the center of electrodes. And interstitial hyperthermia using 8 MHz radiofrequency was carried out. The results of the treatment were evaluated with CT scan based on criteria of the Japan Neurological Society. In cases of malignant gliomas, 2 PRs (partial remission), and 1 NC (no change) were obtained. In cases of metastatic tumors, 1 CR (complete remission), 2 PRs, 1 NC were obtaind. In cases of NCs, progression of tumors have been suppressed for 10 and 17 months, and still alive. As complication, transient worsening of neurological symptoms were observed in four cases (increased paresis: two cases, nausea and vomiting: two cases). The author have had an impression that interstitial hyperthermia combined with interstitial irradiation might become an effective means of treatment of brain tumors. (author)

  11. SR-1000 radiofrequency chemo-hyperthermia for recurrent and metastatic peritoneo-pelvic malignant tumors

    International Nuclear Information System (INIS)

    Luo Jingwei; Xiong Jinghong; Xu Guozhen; Yu Zihao; Li Yexiong; Yin Weibo

    2002-01-01

    Objective: To evaluate the efficacy and tolerance of intraperitoneal chemo-hyperthermia (IPCH) with SR-1000 radiofrequency (RF) for recurrent or metastatic peritoneo-pelvic malignant tumors. Methods: Twenty-one patients with recurrent or metastatic peritoneo-pelvic malignant tumors received chemo-hyperthermia, with 9 having local pain and 14 having ascites. The Karnofsky scores were 40-80. After abdominal cavity aspiration and infusion of hot NS and chemotherapeutic agents, the temperature of abdominal cavity was increased and maintained at 40.5-42.5 degree C for 60-90 minutes with SR-1000 RF. Hyperthermia was given twice per week and chemotherapy once per week, with the whole treatment lasting for 2-4 weeks. The commonly used drugs were DDP, MMC, 5-FU and so on. Results: Local pain was relieved in 8 of 9 patients, complete disappearance of ascites in 10 of 14. The common side-effects were fat necrosis (14.3%) and abdominal pain (24.8%). Conclusions: Intraperitoneal chemo-hyperthermia with SR-1000 RF appears to be a promising new approach for patients with recurrent or metastatic peritoneo-pelvic malignant tumors, especially for those who did not response to systemic chemotherapy or whose tumor recurred after chemotherapy. As to bulky lesions, local supplementary radiotherapy should be given in order to obtain better local control

  12. [Modeling of processes of heat transfer in whole-body hyperthermia].

    Science.gov (United States)

    Kinsht, D N

    2006-01-01

    The method of whole-body hyperthermia in which the body temperature for a short time reaches values up to 43-44 degrees C holds currently much promise. However, at body temperatures above 42 degrees C, the risks associated with the hemodynamic instability and the appearance of arrhythmia in the patient increase. A model of heat transfer has been created to increase the efficiency and safety of the immersion-convectional method of whole-body hyperthermia. This model takes into account changes in the skin blood flow and the dynamics of pulse rate depending on body temperature. The model of heat transfer adequately reflects processes of heating of the organism and can form a basis for the calculation of distribution of heat inside the organism.

  13. Potential effects of diurnal temperature oscillations on potato late blight with special reference to climate change.

    Science.gov (United States)

    Shakya, S K; Goss, E M; Dufault, N S; van Bruggen, A H C

    2015-02-01

    Global climate change will have effects on diurnal temperature oscillations as well as on average temperatures. Studies on potato late blight (Phytophthora infestans) development have not considered daily temperature oscillations. We hypothesize that growth and development rates of P. infestans would be less influenced by change in average temperature as the magnitude of fluctuations in daily temperatures increases. We investigated the effects of seven constant (10, 12, 15, 17, 20, 23, and 27°C) and diurnally oscillating (±5 and ±10°C) temperatures around the same means on number of lesions, incubation period, latent period, radial lesion growth rate, and sporulation intensity on detached potato leaves inoculated with two P. infestans isolates from clonal lineages US-8 and US-23. A four-parameter thermodynamic model was used to describe relationships between temperature and disease development measurements. Incubation and latency progression accelerated with increasing oscillations at low mean temperatures but slowed down with increasing oscillations at high mean temperatures (P effects of global climate change on disease development.

  14. Magnetic hyperthermia dosimetry by biomechanical properties revealed in magnetomotive optical coherence elastography (MM-OCE) (Conference Presentation)

    Science.gov (United States)

    Huang, Pin-Chieh; Marjanovic, Marina; Spillman, Darold R.; Odintsov, Boris M.; Boppart, Stephen A.

    2016-03-01

    Magnetic nanoparticles (MNPs) have been utilized in magnetic hyperthermia to treat solid tumors. Under an appropriate AC magnetic field, energy can be transferred to the MNPs to heat up the intended tissue target while sparing non-targeted healthy tissue. However, a sensitive monitoring technique for the dose of MNP thermal therapy is desirable in order to prevent over-treatment and collateral injury. Typical hyperthermia dosimetry often relies on changes in imaging properties or temperature measurements based on the thermal distribution. Alternative dosimetric indicators can include the biomechanical properties of the tissue, reflecting the changes due to protein denaturation, coagulation, and tissue dehydration during hyperthermia treatments. Tissue stiffness can be probed by elastography modalities including MRI, ultrasound imaging, and optical coherence elastography (OCE), with OCE showing the highest displacement sensitivity (tens of nanometers). Magnetomotive optical coherence elastography (MM-OCE) is one type of OCE that utilizes MNPs as internal force transducers to probe the tissue stiffness. Therefore, we examined the feasibility of evaluating the hyperthermia dose based on the elasticity changes revealed by MM-OCE. Superparamagnetic MNPs were applied to ex vivo tissue specimens for both magnetic hyperthermia and MM-OCE experiments, where temperature and elastic modulus were obtained. A correlation between temperature rise and measured stiffness was observed. In addition, we found that with repetitive sequential treatments, tissue stiffness increased, while temperature rise remained relatively constant. These results potentially suggest that MM-OCE could indicate the irreversible changes the tissue undergoes during thermal therapy, which supports the idea for MM-OCE-based hyperthermia dosage control in future applications.

  15. Part-body hyperthermia with a radiofrequency multiantenna applicator under online control in 1,5 T MR-tomograph

    International Nuclear Information System (INIS)

    Wust, P.; Gellermann, J.; Faehling, H.; Wlodarczyk, W.; Felix, R.; Seebass, M.; Turner, P.; Nadobny, J.; Rau, B.; Hildebrandt, B.; Schlag, P.M.; Oppelt, A.

    2004-01-01

    Objective of this study is the integration of a multiantenna applicator for part-body hyperthermia (BSD 2000/3D) in a 1.5 T MR-tomograph (Siemens Magnetom Symphony) in order to perform noninvasive MR monitoring in real time to increase safety and effectiveness of heat treatments. The positioning unit is mechanically coupled to the MR gantry from the back side and the body coil is utilised for imaging. For that purpose, the hyperthermia antenna system (100 MHz, 1.500 W) and the MR receiver(63.9 MHs) have to be decoupled in terms of high frequency (filter) and electromagnetically (emc). The processing of MR data sets is performed in a hyperthermia planning system. A simultaneous operation of radiofrequency hyperthermia and MR system is possible at clinically relevant power levels. MR imaging is used for tumor diagnostics (standard spin echo sequences), for hyperthermia planning (T1-weighted gradient echo sequences in equal- and opposed-phase techniques), and for temperature measurements according to the proton resonance frequency method (PRF method, phase evaluation registration using a gradient echo sequence with long echo time). In 33 patients with advanced pelvic and abdominal tumors we performed 150 heat sessions under MR monitoring. For 70% of these patients a visualisation of temperature sensitive data during treatment was possible. The evaluated difference images represent a superposition of real temperature increase and a (temperature-induced) perfusion elevation. The hybrid approach renders development of part body hyperthermia possible as an MR-controlled intervention in radiology. (orig.) [de

  16. Optimized Flow Sheet for a Reference Commercial-Scale Nuclear-Driven High-Temperature Electrolysis Hydrogen Production Plant

    International Nuclear Information System (INIS)

    M. G. McKellar; J. E. O'Brien; E. A. Harvego; J. S. Herring

    2007-01-01

    This report presents results from the development and optimization of a reference commercial scale high-temperature electrolysis (HTE) plant for hydrogen production. The reference plant design is driven by a high-temperature helium-cooled reactor coupled to a direct Brayton power cycle. The reference design reactor power is 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 540 C and 900 C, respectively. The electrolysis unit used to produce hydrogen consists of 4.176 - 10 6 cells with a per-cell active area of 225 cm2. A nominal cell area-specific resistance, ASR, value of 0.4 Ohm-cm2 with a current density of 0.25 A/cm2 was used, and isothermal boundary conditions were assumed. The optimized design for the reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes an air-sweep system to remove the excess oxygen that is evolved on the anode side of the electrolyzer. The inlet air for the air-sweep system is compressed to the system operating pressure of 5.0 MPa in a four-stage compressor with intercooling. The overall system thermal-to-hydrogen production efficiency (based on the low heating value of the produced hydrogen) is 49.07% at a hydrogen production rate of 2.45 kg/s with the high-temperature helium-cooled reactor concept. The information presented in this report is intended to establish an optimized design for the reference nuclear-driven HTE hydrogen production plant so that parameters can be compared with other hydrogen production methods and power cycles to evaluate relative performance characteristics and plant economics

  17. Precise determination of the heat delivery during in vivo magnetic nanoparticle hyperthermia with infrared thermography

    Science.gov (United States)

    Rodrigues, Harley F.; Capistrano, Gustavo; Mello, Francyelli M.; Zufelato, Nicholas; Silveira-Lacerda, Elisângela; Bakuzis, Andris F.

    2017-05-01

    Non-invasive and real-time monitoring of the heat delivery during magnetic nanoparticle hyperthermia (MNH) is of fundamental importance to predict clinical outcomes for cancer treatment. Infrared thermography (IRT) can determine the surface temperature due to three-dimensional heat delivery inside a subcutaneous tumor, an argument that is supported by numerical simulations. However, for precise temperature determination, it is of crucial relevance to use a correct experimental configuration. This work reports an MNH study using a sarcoma 180 murine tumor containing 3.9 mg of intratumorally injected manganese-ferrite nanoparticles. MNH was performed at low field amplitude and non-uniform field configuration. Five 30 min in vivo magnetic hyperthermia experiments were performed, monitoring the surface temperature with a fiber optical sensor and thermal camera at distinct angles with respect to the animal’s surface. The results indicate that temperature errors as large as 7~\\circ C can occur if the experiment is not properly designed. A new IRT error model is found to explain the data. More importantly, we show how to precisely monitor temperature with IRT during hyperthermia, which could positively impact heat dosimetry and clinical planning.

  18. Children and adults exposed to electromagnetic fields at the ICNIRP reference levels: theoretical assessment of the induced peak temperature increase

    Energy Technology Data Exchange (ETDEWEB)

    Bakker, J F; Paulides, M M; Van Rhoon, G C [Erasmus MC-Daniel den Hoed Cancer Center, Department of Radiation Oncology, Section Hyperthermia, PO Box 5201, NL-3008 AE, Rotterdam (Netherlands); Neufeld, E; Christ, A; Kuster, N, E-mail: j.bakker@erasmusmc.nl [Foundation for Research on Information Technologies in Society (IT' IS) (Switzerland)

    2011-08-07

    To avoid potentially adverse health effects of electromagnetic fields (EMF), the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined EMF reference levels. Restrictions on induced whole-body-averaged specific absorption rate (SAR{sub wb}) are provided to keep the whole-body temperature increase (T{sub body,incr}) under 1 deg. C during 30 min. Additional restrictions on the peak 10 g spatial-averaged SAR (SAR{sub 10g}) are provided to prevent excessive localized tissue heating. The objective of this study is to assess the localized peak temperature increase (T{sub incr,max}) in children upon exposure at the reference levels. Finite-difference time-domain modeling was used to calculate T{sub incr,max} in six children and two adults exposed to orthogonal plane-wave configurations. We performed a sensitivity study and Monte Carlo analysis to assess the uncertainty of the results. Considering the uncertainties in the model parameters, we found that a peak temperature increase as high as 1 deg. C can occur for worst-case scenarios at the ICNIRP reference levels. Since the guidelines are deduced from temperature increase, we used T{sub incr,max} as being a better metric to prevent excessive localized tissue heating instead of localized peak SAR. However, we note that the exposure time should also be considered in future guidelines. Hence, we advise defining limits on T{sub incr,max} for specified durations of exposure.

  19. Children and adults exposed to electromagnetic fields at the ICNIRP reference levels: theoretical assessment of the induced peak temperature increase.

    Science.gov (United States)

    Bakker, J F; Paulides, M M; Neufeld, E; Christ, A; Kuster, N; van Rhoon, G C

    2011-08-07

    To avoid potentially adverse health effects of electromagnetic fields (EMF), the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined EMF reference levels. Restrictions on induced whole-body-averaged specific absorption rate (SAR(wb)) are provided to keep the whole-body temperature increase (T(body, incr)) under 1 °C during 30 min. Additional restrictions on the peak 10 g spatial-averaged SAR (SAR(10g)) are provided to prevent excessive localized tissue heating. The objective of this study is to assess the localized peak temperature increase (T(incr, max)) in children upon exposure at the reference levels. Finite-difference time-domain modeling was used to calculate T(incr, max) in six children and two adults exposed to orthogonal plane-wave configurations. We performed a sensitivity study and Monte Carlo analysis to assess the uncertainty of the results. Considering the uncertainties in the model parameters, we found that a peak temperature increase as high as 1 °C can occur for worst-case scenarios at the ICNIRP reference levels. Since the guidelines are deduced from temperature increase, we used T(incr, max) as being a better metric to prevent excessive localized tissue heating instead of localized peak SAR. However, we note that the exposure time should also be considered in future guidelines. Hence, we advise defining limits on T(incr, max) for specified durations of exposure.

  20. Neuronal Rat Brain Damage Caused by Endogenous and Exogenous Hyperthermia

    Directory of Open Access Journals (Sweden)

    Mustafa Aydın

    2012-03-01

    Full Text Available OBJECTIVE: Hyperthermia may induce pathologic alterations within body systems and organs including brain. In this study, neuronal effects of endogenous and exogenous hyperthermia (41°C were studied in rats. METHODS: The endogenous hyperthermia (41°C was induced by lipopolysaccharide and the exogenous by an (electric heater. Possible neuronal damage was evaluated by examining healthy, apoptotic and necrotic cells, and heat shock proteins (HSP 27, HSP 70 in the cerebral cortex, cerebellum and hypothalamus RESULTS: At cellular level, when all neuronal tissues are taken into account; (i a significant increase in the necrotic cells was observed in the both groups (p0.05. CONCLUSION: The neural tissue of brain can show different degree of response to hyperthermia. But we can conclude that endogenous hyperthermia is more harmful to central nervous system than exogenous hyperthermia

  1. Online Adaptive Hyperthermia Treatment Planning During Locoregional Heating to Suppress Treatment-Limiting Hot Spots.

    Science.gov (United States)

    Kok, H Petra; Korshuize-van Straten, Linda; Bakker, Akke; de Kroon-Oldenhof, Rianne; Geijsen, Elisabeth D; Stalpers, Lukas J A; Crezee, Johannes

    2017-11-15

    Adequate tumor temperatures during hyperthermia are essential for good clinical response, but excessive heating of normal tissue should be avoided. This makes locoregional heating using phased array systems technically challenging. Online application of hyperthermia treatment planning could help to improve the heating quality. The aim of this study was to evaluate the clinical benefit of online treatment planning during treatment of pelvic tumors heated with the AMC-8 locoregional hyperthermia system. For online adaptive hyperthermia treatment planning, a graphical user interface was developed. Electric fields were calculated in a preprocessing step using our in-house-developed finite-difference-based treatment planning system. This allows instant calculation of the temperature distribution for user-selected phase-amplitude settings during treatment and projection onto the patient's computed tomographic scan for online visualization. Online treatment planning was used for 14 treatment sessions in 8 patients to reduce the patients' reports of hot spots while maintaining the same level of tumor heating. The predicted decrease in hot spot temperature should be at least 0.5°C, and the tumor temperature should decrease less than 0.2°C. These predictions were compared with clinical data: patient feedback about the hot spot and temperature measurements in the tumor region. In total, 17 hot spot reports occurred during the 14 sessions, and the alternative settings predicted the hot spot temperature to decrease by at least 0.5°C, which was confirmed by the disappearance of all 17 hot spot reports. At the same time, the average tumor temperature was predicted to change on average -0.01°C (range, -0.19°C to 0.34°C). The measured tumor temperature change was on average only -0.02°C (range, -0.26°C to 0.31°C). In only 2 cases the temperature decrease was slightly larger than 0.2°C, but at most it was 0.26°C. Online application of hyperthermia treatment planning is

  2. Optimum Temperature for Storage of Fruit and Vegetables with Reference to Chilling Injury

    Science.gov (United States)

    Murata, Takao

    Cold storage is an important technique for preserving fresh fruit and vegetables. Deterioration due to ripening, senescence and microbiological disease can be retarded by storage at optimum temperature being slightly above the freezing point of tissues of fruit and vegetables. However, some fruit and vegetables having their origins in tropical or subtropical regions of the world are subject to chilling injury during transportation, storage and wholesale distribution at low temperature above freezing point, because they are usually sensitive to low temperature in the range of 15&digC to 0°C. This review will focus on the recent informations regarding chilling injury of fruit and vegetables, and summarize the optimum temperature for transportation and storage of fruit and vegetables in relation to chilling injury.

  3. Combined transperineal radiofrequency (RF) interstitial hyperthermia and brachytherapy for localized prostate cancer (PC)

    International Nuclear Information System (INIS)

    Urakami, Shinji; Gonda, Nobuko; Kikuno, Nobuyuki

    2001-01-01

    Hyperthermia has been used effectively as a radiation sensitizer. Interstitial hyperthermoradiotherapy has been therefore utilized as a minimal invasive therapy in attempts to improve local tumor control for various cancers, but not for urological cancer. The purpose of this study was to investigate the safety and feasibility of transperineal hyperthermoradiotherapy for localized PC. Based on our basic study of hyperthermoradiotherapy, we devised the procedure of combined transperineal RF interstitial hyperthermia and brachytherapy for localized prostate cancer. Two patients with localized PC underwent transperineal RF interstitial hyperthermia combined with brachytherapy operation the 192-Ir remote after-loading system (RALS). Under transrectal ultrasound guidance, a total number of 12-18 stainless steel needles for 192-Ir RALS were implanted into the prostatic gland and seminal vesicles (SV) in an optimized pattern. Eight of the needles were used as electrodes for hyperthermia, and were electrically insultated using the vinyl catheter along the length of the subdermal fatty tissue to protect from overheating. Three other needles were utilized for continuous temperature mapping in the prostate. Rectal temperature was also monitored. Total radiation doses of 70 Gy to the prostate and SV were planned as a combination of brachytherapy (24 Gy/4 fraction) and external irradiation using a four-field box technique (46 Gy/23 fraction). Hyperthermic treatment (goal of 42 to 43 deg C for 60 minutes) was performed twice following the 1st and 4th brachytherapy at an interval of more than 48 hours for the recovery of cancer cells from thermotolerance. Both patients reached the treatment goal of all intraprostatic temperatures >43.0 deg C, which was considered favorable for hyperthermia, and the rectal temperatures of both patients remained <38 deg C during hyperthermia. In serial PSA measurements of both patients, serum PSA was less than 1.0 ng/ml within 3 months and has since

  4. Clinical use of the hyperthermia treatment planning system HyperPlan to predict effectiveness and toxicity

    International Nuclear Information System (INIS)

    Sreenivasa, Geetha; Gellermann, Johanna; Rau, Beate; Nadobny, Jacek; Schlag, Peter; Deuflhard, Peter; Felix, Roland; Wust, Peter

    2003-01-01

    Purpose: The main aim is to prove the clinical practicability of the hyperthermia treatment planning system HyperPlan on a β-test level. Data and observations obtained from clinical hyperthermia are compared with the numeric methods FE (finite element) and FDTD (finite difference time domain), respectively. Methods and Materials: The planning system HyperPlan is built on top of the modular, object-oriented platform for visualization and model generation AMIRA. This system already contains powerful algorithms for image processing, geometric modeling, and three-dimensional graphics display. A number of hyperthermia-specific modules are provided, enabling the creation of three-dimensional tetrahedral patient models suitable for treatment planning. Two numeric methods, FE and FDTD, are implemented in HyperPlan for solving Maxwell's equations. Both methods base their calculations on segmented (contour based) CT or MR image data. A tetrahedral grid is generated from the segmented tissue boundaries, consisting of approximately 80,000 tetrahedrons per patient. The FE method necessitates, primarily, this tetrahedral grid for the calculation of the E-field. The FDTD method, on the other hand, calculates the E-field on a cubical grid, but also requires a tetrahedral grid for correction at electrical interfaces. In both methods, temperature distributions are calculated on the tetrahedral grid by solving the bioheat transfer equation with the FE method. Segmentation, grid generation, E-field, and temperature calculation can be carried out in clinical practice at an acceptable time expenditure of about 1-2 days. Results: All 30 patients we analyzed with cervical, rectal, and prostate carcinoma exhibit a good correlation between the model calculations and the attained clinical data regarding acute toxicity (hot spots), prediction of easy-to-heat or difficult-to-heat patients, and the dependency on various other individual parameters. We could show sufficient agreement between

  5. Thermal sensation during mild hyperthermia is modulated by acute postural change in humans.

    Science.gov (United States)

    Takeda, Ryosuke; Imai, Daiki; Suzuki, Akina; Ota, Akemi; Naghavi, Nooshin; Yamashina, Yoshihiro; Hirasawa, Yoshikazu; Yokoyama, Hisayo; Miyagawa, Toshiaki; Okazaki, Kazunobu

    2016-12-01

    Thermal sensation represents the primary stimulus for behavioral and autonomic thermoregulation. We assessed whether the sensation of skin and core temperatures for the driving force of behavioral thermoregulation was modified by postural change from the supine (Sup) to sitting (Sit) during mild hyperthermia. Seventeen healthy young men underwent measurements of noticeable increase and decrease (±0.1 °C/s) of skin temperature (thresholds of warm and cold sensation on the skin, 6.25 cm 2 of area) at the forearm and chest and of the whole-body warm sensation in the Sup and Sit during normothermia (NT; esophageal temperature (T es ), ∼36.6 °C) and mild hyperthermia (HT; T es , ∼37.2 °C; lower legs immersion in 42 °C of water). The threshold for cold sensation on the skin at chest was lower during HT than NT in the Sit (P sensation on the skin at both sites remained unchanged with changes in body posture or temperature. The whole-body warm sensation was higher during HT than NT in both postures and higher in the Sit than Sup during both NT and HT (all, P sensation during mild hyperthermia is modulated by postural change from supine to sitting to sense lesser cold on the skin and more whole-body warmth.

  6. Hyperthermia: an effective strategy to induce apoptosis in cancer cells.

    Science.gov (United States)

    Ahmed, Kanwal; Tabuchi, Yoshiaki; Kondo, Takashi

    2015-11-01

    Heat has been used as a medicinal and healing modality throughout human history. The combination of hyperthermia (HT) with radiation and anticancer agents has been used clinically and has shown positive results to a certain extent. However, the clinical results of HT treatment alone have been only partially satisfactory. Cell death following HT treatment is a function of both temperature and treatment duration. HT induces cancer cell death through apoptosis; the degree of apoptosis and the apoptotic pathway vary in different cancer cell types. HT-induced reactive oxygen species production are responsible for apoptosis in various cell types. However, the underlying mechanism of signal transduction and the genes related to this process still need to be elucidated. In this review, we summarize the molecular mechanism of apoptosis induced by HT, enhancement of heat-induced apoptosis, and the genetic network involved in HT-induced apoptosis.

  7. Reference book for design of valve packings, sealing high temperature water

    International Nuclear Information System (INIS)

    Doubt, G.L.

    1976-01-01

    Mockups of stuffing boxes for valves in the 1/4 to 1 in. (0.6-2.54cm) pipe size range and ASA 900 and up pressure class were tested to determine how temperature, stuffing box dimensions, packing compressive stress and stem surface finish affect water leak rate, packing friction torque and packing volume loss (creep). One brand of wire-reinforced asbestos braid on graphite-and-asbestos core packing was used in all tests. The theory of leakage through porous media was reviewed with emphasis on application to packed stuffing boxes, and a mathematical framework for relating leakage and packing friction to stuffing box dimensions and compressive stress was developed. The tests gave empirical relationships (1) for leak rate vs temperature, packing compressive stress, stem diameter and packing size, (2) for packing friction torque vs the above variables and (3) for packing creep vs temperature and stress. Packing stress affected leakage far more than any other variable, the leak rate being inversely proportional to stress to the 7.3 power at a packing temperature of 350 deg F (175 deg C). Factors which increase packing compression (density) have a strong reducing effect on leakage and a moderate to zero effect on packing friction torque. Surface finish had no visible effect on leakage, torque or creep. Empirical results and theory have been combined to show how stuffing boxes can be designed for a given leakage rate. Suggestions for decreasing leakage from existing high temperature stuffing boxes are included. (author)

  8. Magnetic hyperthermia with hard-magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kashevsky, Bronislav E., E-mail: bekas@itmo.by [A.V Luikov Heat and Mass Transfer Institute, Belarus Academy of Sciences, P. Brovka str. 15, Minsk 220072 (Belarus); Kashevsky, Sergey B.; Korenkov, Victor S. [A.V Luikov Heat and Mass Transfer Institute, Belarus Academy of Sciences, P. Brovka str. 15, Minsk 220072 (Belarus); Istomin, Yuri P. [N. N. Alexandrov National Cancer Center of Belarus, Lesnoy-2, Minsk 223040 (Belarus); Terpinskaya, Tatyana I.; Ulashchik, Vladimir S. [Institute of Physiology, Belarus Academy of Sciences, Akademicheskaya str. 28, Minsk 220072 (Belarus)

    2015-04-15

    Recent clinical trials of magnetic hyperthermia have proved, and even hardened, the Ankinson-Brezovich restriction as upon magnetic field conditions applicable to any site of human body. Subject to this restriction, which is harshly violated in numerous laboratory and small animal studies, magnetic hyperthermia can relay on rather moderate heat source, so that optimization of the whole hyperthermia system remains, after all, the basic problem predetermining its clinical perspectives. We present short account of our complex (theoretical, laboratory and small animal) studies to demonstrate that such perspectives should be related with the hyperthermia system based on hard-magnetic (Stoner–Wohlfarth type) nanoparticles and strong low-frequency fields rather than with superparamagnetic (Brownian or Neél) nanoparticles and weak high-frequency fields. This conclusion is backed by an analytical evaluation of the maximum absorption rates possible under the field restriction in the ideal hard-magnetic (Stoner–Wohlarth) and the ideal superparamagnetic (single relaxation time) systems, by theoretical and experimental studies of the dynamic magnetic hysteresis in suspensions of movable hard-magnetic particles, by producing nanoparticles with adjusted coercivity and suspensions of such particles capable of effective energy absorption and intratumoral penetration, and finally, by successful treatment of a mice model tumor under field conditions acceptable for whole human body. - Highlights: • Hard-magnetic nanoparticles are shown superior for hyperthetmia to superparamagnetic. • Optimal system parameters are found from magnetic reversal model in movable particle. • Penetrating suspension of HM particles with aggregation-independent SAR is developed. • For the first time, mice with tumors are healed in AC field acceptable for human body.

  9. Passive multi-frequency brain imaging and hyperthermia irradiation apparatus: the use of dielectric matching materials in phantom experiments

    International Nuclear Information System (INIS)

    Gouzouasis, Ioannis; Karathanasis, Konstantinos; Karanasiou, Irene; Uzunoglu, Nikolaos

    2009-01-01

    In this paper a hybrid system able to provide focused microwave radiometry and deep brain hyperthermia is experimentally tested. The system's main module is an ellipsoidal conductive wall cavity which acts as a beam former, focusing the electromagnetic energy on the medium of interest. The system's microwave radiometry component has extensively been studied theoretically and experimentally in the past few years with promising results. In this work, further investigation concerning the improvement of the hybrid system's focusing properties is conducted. Specifically, microwave radiometry and hyperthermia experiments are performed using water phantoms surrounded by dielectric layers used as matching material to enhance detection/penetration depth and spatial resolution. The results showed that the dielectric material reduces the reflected electromagnetic energy on the air–phantom interface, resulting in improved temperature resolution and higher detection or penetration of the energy when microwave radiometry and hyperthermia are applied respectively

  10. Thermal dosimetry for bladder hyperthermia treatment. An overview.

    Science.gov (United States)

    Schooneveldt, Gerben; Bakker, Akke; Balidemaj, Edmond; Chopra, Rajiv; Crezee, Johannes; Geijsen, Elisabeth D; Hartmann, Josefin; Hulshof, Maarten C C M; Kok, H Petra; Paulides, Margarethus M; Sousa-Escandon, Alejandro; Stauffer, Paul R; Maccarini, Paolo F

    2016-06-01

    The urinary bladder is a fluid-filled organ. This makes, on the one hand, the internal surface of the bladder wall relatively easy to heat and ensures in most cases a relatively homogeneous temperature distribution; on the other hand the variable volume, organ motion, and moving fluid cause artefacts for most non-invasive thermometry methods, and require additional efforts in planning accurate thermal treatment of bladder cancer. We give an overview of the thermometry methods currently used and investigated for hyperthermia treatments of bladder cancer, and discuss their advantages and disadvantages within the context of the specific disease (muscle-invasive or non-muscle-invasive bladder cancer) and the heating technique used. The role of treatment simulation to determine the thermal dose delivered is also discussed. Generally speaking, invasive measurement methods are more accurate than non-invasive methods, but provide more limited spatial information; therefore, a combination of both is desirable, preferably supplemented by simulations. Current efforts at research and clinical centres continue to improve non-invasive thermometry methods and the reliability of treatment planning and control software. Due to the challenges in measuring temperature across the non-stationary bladder wall and surrounding tissues, more research is needed to increase our knowledge about the penetration depth and typical heating pattern of the various hyperthermia devices, in order to further improve treatments. The ability to better determine the delivered thermal dose will enable clinicians to investigate the optimal treatment parameters, and consequentially, to give better controlled, thus even more reliable and effective, thermal treatments.

  11. Biodegradable magnesium nanoparticle-enhanced laser hyperthermia therapy

    Directory of Open Access Journals (Sweden)

    Wang Q

    2012-08-01

    Full Text Available Qian Wang,1 Liping Xie,1 Zhizhu He,2 Derui Di,2 Jing Liu1,21Department of Biomedical Engineering, School of Medicine, Tsinghua University, 2Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, People's Republic of ChinaBackground: Recently, nanoparticles have been demonstrated to have tremendous merit in terms of improving the treatment specificity and thermal ablation effect on tumors. However, the potential toxicity and long-term side effects caused by the introduced nanoparticles and by expelling them out of the body following surgery remain a significant challenge. Here, we propose for the first time to directly adopt magnesium nanoparticles as the heating enhancer in laser thermal ablation to avoid these problems by making full use of the perfect biodegradable properties of this specific material.Methods: To better understand the new nano “green” hyperthermia modality, we evaluated the effects of magnesium nanoparticles on the temperature transients inside the human body subject to laser interstitial heating. Further, we experimentally investigated the heating enhancement effects of magnesium nanoparticles on a group of biological samples: oil, egg white, egg yolk, in vitro pig tissues, and the in vivo hind leg of rabbit when subjected to laser irradiation.Results: Both the theoretical simulations and experimental measurements demonstrated that the target tissues injected with magnesium nanoparticles reached much higher temperatures than tissues without magnesium nanoparticles. This revealed the enhancing behavior of the new nanohyperthermia method.Conclusion: Given the unique features of magnesium nanoparticles – their complete biological safety and ability to enhance heating – which most other advanced metal nanoparticles do not possess, the use of magnesium nanoparticles in hyperthermia therapy offers an important “green” nanomedicine modality for treating tumors

  12. Altered lipid homeostasis in Sertoli cells stressed by mild hyperthermia.

    Directory of Open Access Journals (Sweden)

    Ana S Vallés

    Full Text Available Spermatogenesis is known to be vulnerable to temperature. Exposures of rat testis to moderate hyperthermia result in loss of germ cells with survival of Sertoli cells (SC. Because SC provide structural and metabolic support to germ cells, our aim was to test the hypothesis that these exposures affect SC functions, thus contributing to germ cell damage. In vivo, regularly repeated exposures (one of 15 min per day, once a day during 5 days of rat testes to 43 °C led to accumulation of neutral lipids. This SC-specific lipid function took 1-2 weeks after the last of these exposures to be maximal. In cultured SC, similar daily exposures for 15 min to 43 °C resulted in significant increase in triacylglycerol levels and accumulation of lipid droplets. After incubations with [3H]arachidonate, the labeling of cardiolipin decreased more than that of other lipid classes. Another specifically mitochondrial lipid metabolic function, fatty acid oxidation, also declined. These lipid changes suggested that temperature affects SC mitochondrial physiology, which was confirmed by significantly increased degrees of membrane depolarization and ROS production. This concurred with reduced expression of two SC-specific proteins, transferrin, and Wilms' Tumor 1 protein, markers of SC secretion and differentiation functions, respectively, and with an intense SC cytoskeletal perturbation, evident by loss of microtubule network (α-tubulin and microfilament (f-actin organization. Albeit temporary and potentially reversible, hyperthermia-induced SC structural and metabolic alterations may be long-lasting and/or extensive enough to respond for the decreased survival of the germ cells they normally foster.

  13. Role of blood flow and blood flow modifiers in clinical hyperthermia therapy

    International Nuclear Information System (INIS)

    Olch, A.J.

    1986-01-01

    A quantitative assessment of the effect of localized magnetic-loop hyperthermia on blood flow was performed on 12 patients (19 tumor studies) using the Xenon-133 clearance method. After it was discovered that blood flow in most of the tumors increased in response to needle injection, a physiologically based, one compartment model was developed that included both a hyperemic (transient) and a steady state component. In the tumors of six patients, increases in blood flow induced by heat were also observed. The same model was used to describe the measured clearance data for both types of hyperemic response. The ability of tumor vessels to respond dynamically to stress and the degree of response may be predictive of tumor heating efficiency and subsequent therapeutic response. Many tumors treated by hyperthermia, therefore, do not reach therapeutic temperatures (42 0 C). One explanation for this may be that some tumors react to thermal stress in a manner similar to normal tissues; i.e., they increase blood flow during hyperthermia in order to dissipate heat. Higher temperatures might be achieved in these heat-resistant tumors by administering vasoconstrictive agents in an effort to reduce blood flow. In the second part of this research study, the extent to which pharmacologic inhibition of local blood flow might allow higher temperatures to develop in normal muscles exposed to localized radiofrequency hyperthermia was determined. It was found that the local muscle temperature rise could be increased by at least 90% in dogs and rabbits with the use of a local vasoconstrictive drug

  14. Investigation of particle accumulation, chemosensitivity and thermosensitivity for effective solid tumor therapy using thermosensitive liposomes and hyperthermia

    NARCIS (Netherlands)

    W.J.M. Lokerse (Wouter); M. Bolkestein (Michiel); T.L.M. ten Hagen (Timo); M. de Jong (Marcel); A.M.M. Eggermont (Alexander); Grüll, H. (Holger); G.A. Koning (Gerben)

    2016-01-01

    textabstractDoxorubicin (Dox) loaded thermosensitive liposomes (TSLs) have shown promising results for hyperthermia-induced local drug delivery to solid tumors. Typically, the tumor is heated to hyperthermic temperatures (41-42 °C), which induced intravascular drug release from TSLs within the tumor

  15. A study of effects of hyperthermia on large, short-haired male dogs : a simulated air transport environmental stress.

    Science.gov (United States)

    1977-03-01

    When dogs are shipped by air transport, they can encounter environmental temperatures as high as 130.0 F during the summer months. Heat- induced hyperthermia can be a major problem in dogs. : To assess some aspects of the heat stress problem, 20 dogs...

  16. Modeling of heat transfer in a vascular tissue-like medium during an interstitial hyperthermia process.

    Science.gov (United States)

    Hassanpour, Saeid; Saboonchi, Ahmad

    2016-12-01

    This paper aims to evaluate the role of small vessels in heat transfer mechanisms of a tissue-like medium during local intensive heating processes, for example, an interstitial hyperthermia treatment. To this purpose, a cylindrical tissue with two co- and counter-current vascular networks and a central heat source is introduced. Next, the energy equations of tissue, supply fluid (arterial blood), and return fluid (venous blood) are derived using porous media approach. Then, a 2D computer code is developed to predict the temperature of blood (fluid phase) and tissue (solid phase) by conventional volume averaging method and a more realistic solution method. In latter method, despite the volume averaging the blood of interconnect capillaries is separated from the arterial and venous blood phases. It is found that in addition to blood perfusion rate, the arrangement of vascular network has considerable effects on the pattern and amount of the achieved temperature. In contrast to counter-current network, the co-current network of vessels leads to considerable asymmetric pattern of temperature contours and relocation of heat affected zone along the blood flow direction. However this relocation can be prevented by changing the site of hyperthermia heat source. The results show that the cooling effect of co-current blood vessels during of interstitial heating is more efficient. Despite much anatomical dissimilarities, these findings can be useful in designing of protocols for hyperthermia cancer treatment of living tissue. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Modeling the heat transfer problem for the novel combined cryosurgery and hyperthermia system.

    Science.gov (United States)

    Zhao, Gang; Bai, Xue-Fei; Luo, Da-Wei; Gao, Da-Yong

    2006-01-01

    A multidimensional, finite element analysis (FEA) for the freezing, holding, rewarming and heating processes of biological tissues during the cryosurgery process of the new Combined Cryosurgery/Hyperthermia System is presented to theoretically test its validity. The tissues are treated as nonideal materials freezing over a temperature range, and the thermophysical properties of which are temperature dependent. The enthalpy method is applied to solve the highly nonlinear problem. It was found that when the same boundary condition and the same target tissue presented, the novel Cryosurgery/Hyperthermia System could supply the target tissue an approximative cooling rate, a much lower minimal temperature, a much greater warming rate, and a much greater thermal gradients compared with that of the simplified Endocare system. The numerical simulation indicates that the novel combined cryosurgery and hyperthermia system can provide an excellent curative effect in the corresponding cryotherapy. And the most attractive feature of this FEA framework is that it can be easily mastered by the surgeon without in-depth theory of heat transfer to analyze the cryosurgery process beforehand due to the friendly GUI (graphical user interface) of Ansys software.

  18. Indomethacin attenuation of radiation-induced hyperthermia does not modify radiation-induced motor hypoactivity

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, J.L.; Kandasamy, S.B.; Harris, A.H.; Davis, H.D.; Landauer, M.R. [Armed Forces Radiobiology Research Inst., Bethesda, MD (United States)

    1996-09-01

    Exposure of rats to 5-10 Gy of ionizing radiation produces hyperthermia and reduces motor activity. Previous studies suggested that radiation-induced hyperthermia results from a relatively direct action on the brain and is mediated by prostaglandins. To test the hypothesis that hypoactivity may be, in part, a thermoregulatory response to this elevation in body temperature, adult male rats were given indomethacin (0.0, 0.5, 1.0, and 3.0 mg/kg, intraperitoneally), a blocker of prostaglandin synthesis, and were either irradiated (LINAC 18.6 MeV (nominal) high-energy electrons, 10 Gy at 10 Gy/min, 2.8 {mu}sec pulses at 2 Hz) or sham-irradiated. The locomotor activity of all rats was then measured for 30 min in a photocell monitor for distance traveled and number of vertical movements. Rectal temperatures of irradiated rats administered vehicle only were elevated by 0.9{+-}0.2degC at the beginning and the end of the activity session. Although indomethacin, at the two higher doses tested, attenuated the hyperthermia in irradiated rats by 52-75%, it did not attenuate radiation-induced reductions in motor activity. These results indicate that motor hypoactivity after exposure to 10 Gy of high-energy electrons is not due to elevated body temperature or to the increased synthesis of prostaglandins. (author)

  19. Indomethacin attenuation of radiation-induced hyperthermia does not modify radiation-induced motor hypoactivity

    International Nuclear Information System (INIS)

    Ferguson, J.L.; Kandasamy, S.B.; Harris, A.H.; Davis, H.D.; Landauer, M.R.

    1996-01-01

    Exposure of rats to 5-10 Gy of ionizing radiation produces hyperthermia and reduces motor activity. Previous studies suggested that radiation-induced hyperthermia results from a relatively direct action on the brain and is mediated by prostaglandins. To test the hypothesis that hypoactivity may be, in part, a thermoregulatory response to this elevation in body temperature, adult male rats were given indomethacin (0.0, 0.5, 1.0, and 3.0 mg/kg, intraperitoneally), a blocker of prostaglandin synthesis, and were either irradiated (LINAC 18.6 MeV (nominal) high-energy electrons, 10 Gy at 10 Gy/min, 2.8 μsec pulses at 2 Hz) or sham-irradiated. The locomotor activity of all rats was then measured for 30 min in a photocell monitor for distance traveled and number of vertical movements. Rectal temperatures of irradiated rats administered vehicle only were elevated by 0.9±0.2degC at the beginning and the end of the activity session. Although indomethacin, at the two higher doses tested, attenuated the hyperthermia in irradiated rats by 52-75%, it did not attenuate radiation-induced reductions in motor activity. These results indicate that motor hypoactivity after exposure to 10 Gy of high-energy electrons is not due to elevated body temperature or to the increased synthesis of prostaglandins. (author)

  20. Preliminary clinical results of locoregional hyperthermia for primary and secondary bone tumors

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, J.L.; Nagata, Yasushi; Kanamori, Shuichi; Mitsumori, Michihide; Okuno, Yoshishige; Horii, Naotoshi; Nishimura, Yasumasa; Masunaga, Shinitiro; Hiraoka, Masahiro [Kyoto Univ. (Japan). Graduate School of Medicine

    2000-03-01

    Nineteen primary and secondary bone tumors in 16 patients were treated with hyperthermia plus radiotherapy and/or chemotherapy between 1982 and 1997 at Kyoto University Hospital. The thermometric and clinical results were analyzed retrospectively. In 55 of 86 hyperthermia sessions, the intratumor temperature was measured using a thermometer. Of the 19 tumors, 16 (84%) received heat treatment 4-7 times, and 3 (16%) received 1 or 2 treatments of hyperthermia. The mean maximum, mean minimum and average intratumor temperatures were 42.9, 40.4 and 41.6 deg C, respectively, and 12 (67%) reached a tumor maximum temperature above 42.5 deg C. The durations that intratumor points exceeded 42, 41 and 40 deg C were 27, 34 and 38 min, respectively. The local tumor response to treatment was assessed using X-ray computed tomography. The local response rate was 16% and the local pain relief rate was 63%. The 1-year cumulative survival rate was 60%. Our preliminary results indicated that thermoradiotherapy and thermochemotherapy are clinicaly feasible and potentially beneficial in the management of locally advanced bone tumors. (author)

  1. Vasomotor response of the human face: laser-Doppler measurements during mild hypo- and hyperthermia.

    Science.gov (United States)

    Rasch, W; Cabanac, M

    1993-04-01

    The skin of the face is reputed not to vasoconstrict in response to cold stress because the face skin temperature remains steady during hypothermia. The purpose of the present work was to measure the vasomotor response of the human face to whole-body hypothermia, and to compare it with hyperthermia. Six male subjects were immersed in cold and in warm water to obtain the two conditions. Skin blood flow, evaporation, and skin temperature (Tsk) were recorded in three loci of the face, the forehead, the infra orbital area, and the cheek. Tympanic (Tty) and oesophageal (Toes) temperatures were also recorded during the different thermal states. Normothermic measurements served as control. Blood flow was recorded with a laser-Doppler flowmeter, evaporation measured with an evaporimeter. Face Tsk remained stable between normo-, hypo-, and hyperthermia. Facial blood flow, however, did not follow the same pattern. The facial blood flow remained at minimal vasoconstricted level when the subjects' condition was changed from normo- to hypothermia. When the condition changed from hypo- to hyperthermia a 3 to 9-fold increase in the blood flow was recorded. From these results it was concluded that a vasoconstriction seems to be the general vasomotor state in the face during normothermia.

  2. Reference modular High Temperature Gas-Cooled Reactor Plant: Concept description report

    Energy Technology Data Exchange (ETDEWEB)

    1986-10-01

    This report provides a summary description of the Modular High Temperature Gas-Cooled Reactor (MHTGR) concept and interim results of assessments of costs, safety, constructibility, operability, maintainability, and availability. Conceptual design of this concept was initiated in October 1985 and is scheduled for completion in 1987. Participating industrial contractors are Bechtel National, Inc. (BNI), Stone and Webster Engineering Corporation (SWEC), GA Technologies, Inc. (GA), General Electric Co. (GE), and Combustion Engineering, Inc. (C-E).

  3. Reference modular High Temperature Gas-Cooled Reactor Plant: Concept description report

    International Nuclear Information System (INIS)

    1986-10-01

    This report provides a summary description of the Modular High Temperature Gas-Cooled Reactor (MHTGR) concept and interim results of assessments of costs, safety, constructibility, operability, maintainability, and availability. Conceptual design of this concept was initiated in October 1985 and is scheduled for completion in 1987. Participating industrial contractors are Bechtel National, Inc. (BNI), Stone and Webster Engineering Corporation (SWEC), GA Technologies, Inc. (GA), General Electric Co. (GE), and Combustion Engineering, Inc

  4. Reference of Temperature and Time during tempering process for non-stoichiometric FTO films

    Science.gov (United States)

    Yang, J. K.; Liang, B.; Zhao, M. J.; Gao, Y.; Zhang, F. C.; Zhao, H. L.

    2015-10-01

    In order to enhance the mechanical strength of Low-E glass, Fluorine-doped tin oxide (FTO) films have to be tempered at high temperatures together with glass substrates. The effects of tempering temperature (600 °C ~ 720 °C) and time (150 s ~ 300 s) on the structural and electrical properties of FTO films were investigated. The results show all the films consist of non-stoichiometric, polycrystalline SnO2 without detectable amounts of fluoride. 700 °C and 260 s may be the critical tempering temperature and time, respectively. FTO films tempered at 700 °C for 260 s possesses the resistivity of 7.54 × 10-4 Ω•cm, the average transmittance in 400 ~ 800 nm of ~80%, and the calculated emissivity of 0.38. Hall mobility of FTO films tempered in this proper condition is mainly limited by the ionized impurity scattering. The value of [O]/[Sn] at the film surface is much higher than the stoichiometric value of 2.0 of pure crystalline SnO2.

  5. Comparison of radiosensitization by 41 deg. C hyperthermia during low dose rate irradiation and during pulsed simulated low dose rate irradiation in human glioma cells

    International Nuclear Information System (INIS)

    Raaphorst, G. Peter; Ng, Cheng E.; Shahine, Bilal

    1999-01-01

    Purpose: Long duration mild hyperthermia has been shown to be an effective radiosensitizer when given concurrently with low dose rate irradiation. Pulsed simulated low dose rate (PSLDR) is now being used clinically, and we have set out to determine whether concurrent mild hyperthermia can be an effective radiosensitizer for the PSLDR protocol. Materials and Methods: Human glioma cells (U-87MG) were grown to plateau phase and treated in plateau phase in order to minimize cell cycle redistribution during protracted treatments. Low dose rate (LDR) irradiation and 41 deg. C hyperthermia were delivered by having a radium irradiator inside a temperature-controlled incubator. PSLDR was given using a 150 kVp X-ray unit and maintaining the cells at 41 deg. C between irradiations. The duration of irradiation and concurrent heating depended on total dose and extended up to 48 h. Results: When 41 deg. C hyperthermia was given currently with LDR or PSLDR, the thermal enhancement ratios (TER) were about the same if the average dose rate for PSLDR was the same as for LDR. At higher average dose rates for PSLDR the TERs became less. Conclusions: Our data show that concurrent mild hyperthermia can be an effective sensitizer for PSLDR. This sensitization can be as effective as for LDR if the same average dose rate is used and the TER increases with decreasing dose rate. Thus mild hyperthermia combined with PSLDR may be an effective clinical protocol

  6. Eight-MHz RF-hyperthermia for advanced urological malignancies

    International Nuclear Information System (INIS)

    Hisazumi, Haruo; Nakajima, Kazuyoshi

    1986-01-01

    Eight-MHz radiofrequency hyperthermia (H) using a Thermotron-RF Model 8, and its combination with irradiation (RH), anticancer drugs (CH) or anticancer drugs plus irradiation (CRH), were carried out for a total of 48 urological malignancies: 10 cases of renal cancer, 1 of renal pelvic cancer, 2 of uretetral cancer, 19 of bladder cancer, 5 of prostatic cancer, 9 of metastatic lesion of urological cancers and 2 of other urological cancers. All had failed in previous treatments, or had not undergone surgery because of their poor general condition. Four cases, including 2 of bladder cancer, 1 of prostatic cancer and 1 of metastatic lesion of bladder cancer, were treated with H. Twenty-five cases, including 3 renal cancer cases, were treated with RH. Seven of the 10 cases of renal cancer were treated with mitomycin C-microcapsule embolization prior to RH (CRH). Twelve of the 23 cases with urothelial cancer or its metastasis, including 1 of renal pelvic cancer, 10 of bladder cancer and 1 of metastatic lesion of bladder cancer, received combined treatment of THP-adriamycin, one of the derivatives of adriamycin, by i.v. and RF-heating (CH). Hyperthermia was given twice a week, totalling 10 sessions in 5 weeks. Intratumoral temperature was kept above 42.5 deg C for 30 to 40 minutes during one-hour heating. Complete tumor disappearance was obtained in the 5 bladder cancer cases. Partial tumor regression, defined as a regression of 50 % or more, was obtained in 11 cases. As side effects, mild skin burns and anorexia were observed in approximately 30 to 40 % of cases. Seven obese cases, who had subcutaneous tissue 15 mm thick or more, developed fat tissue induration after treatment. (author)

  7. Brain temperature and exercise performance

    DEFF Research Database (Denmark)

    Nybo, Lars

    2012-01-01

    Events arising within the central nervous system seem to play a major factor in the aetiology of hyperthermia-induced fatigue. Thus, various studies with superimposed electrical nerve stimulation or transcranial magnetic stimulation have shown that both passive and exercise-induced hyperthermia...... temperature in exercising goats indicate that excessive brain hyperthermia will directly affect motor performance. However, several homeostatic changes arise in parallel with hyperthermia including factors that may influence both peripheral and central fatigue and it is likely that these changes interact...... will impair voluntary motor activation during sustained maximal contractions. In humans the brain temperature increases in parallel with that of the body core making it very difficult to evaluate the independent effect of the cerebral temperature. Experiments with separate manipulation of the brain...

  8. Hemoglobins: models of physiological adaptation, with special reference to O2 availability and temperature

    DEFF Research Database (Denmark)

    Weber, Roy E.

    In transporting O2 from the respiratory surfaces to the respiring tissues of animals, hemoglobin (Hb) directly links aerobic metabolism with O2 availability and is a paradigm for studying mechanisms of molecular adaptations. Hb-O2 binding is cooperative (described by sigmoid O2 binding curves......) and decreased by allosteric effectors (protons, CO2, lactate, organic phosphates and chloride ions) that modulate O2 binding in response to changes in environmental and metabolic dictates. Hb-O2 affinity moreover decreases with rising temperature. This increases O2 unloading in warm tissues that consume more O2......, but may be maladaptive – and thus is reduced - in regional heterothermic animals where it may hamper O2 unloading (in cold extremities of Artic mammals) or cause excessive O2 release (in warm organs of fast-swimming fish). Illustrated with case studies (estivating lungfish, high altitude frogs, birds...

  9. Simple and Rapid Synthesis of Magnetite/Hydroxyapatite Composites for Hyperthermia Treatments via a Mechanochemical Route

    Science.gov (United States)

    Iwasaki, Tomohiro; Nakatsuka, Ryo; Murase, Kenya; Takata, Hiroshige; Nakamura, Hideya; Watano, Satoru

    2013-01-01

    This paper presents a simple method for the rapid synthesis of magnetite/hydroxyapatite composite particles. In this method, superparamagnetic magnetite nanoparticles are first synthesized by coprecipitation using ferrous chloride and ferric chloride. Immediately following the synthesis, carbonate-substituted (B-type) hydroxyapatite particles are mechanochemically synthesized by wet milling dicalcium phosphate dihydrate and calcium carbonate in a dispersed suspension of magnetite nanoparticles, during which the magnetite nanoparticles are incorporated into the hydroxyapatite matrix. We observed that the resultant magnetite/hydroxyapatite composites possessed a homogeneous dispersion of magnetite nanoparticles, characterized by an absence of large aggregates. When this material was subjected to an alternating magnetic field, the heat generated increased with increasing magnetite concentration. For a magnetite concentration of 30 mass%, a temperature increase greater than 20 K was achieved in less than 50 s. These results suggest that our composites exhibit good hyperthermia properties and are promising candidates for hyperthermia treatments. PMID:23629669

  10. Simple and Rapid Synthesis of Magnetite/Hydroxyapatite Composites for Hyperthermia Treatments via a Mechanochemical Route

    Directory of Open Access Journals (Sweden)

    Tomohiro Iwasaki

    2013-04-01

    Full Text Available This paper presents a simple method for the rapid synthesis of magnetite/hydroxyapatite composite particles. In this method, superparamagnetic magnetite nanoparticles are first synthesized by coprecipitation using ferrous chloride and ferric chloride. Immediately following the synthesis, carbonate-substituted (B-type hydroxyapatite particles are mechanochemically synthesized by wet milling dicalcium phosphate dihydrate and calcium carbonate in a dispersed suspension of magnetite nanoparticles, during which the magnetite nanoparticles are incorporated into the hydroxyapatite matrix. We observed that the resultant magnetite/hydroxyapatite composites possessed a homogeneous dispersion of magnetite nanoparticles, characterized by an absence of large aggregates. When this material was subjected to an alternating magnetic field, the heat generated increased with increasing magnetite concentration. For a magnetite concentration of 30 mass%, a temperature increase greater than 20 K was achieved in less than 50 s. These results suggest that our composites exhibit good hyperthermia properties and are promising candidates for hyperthermia treatments.

  11. Intra-operative placement of catheters for interstitial microwave-induced hyperthermia and iridium brachytherapy

    International Nuclear Information System (INIS)

    Coughlin, C.T.; Wong, T.Z.; Strohbehn, J.W.; Colacchio, T.A.; Belch, R.Z.; Sutton, J.E. Jr.; Douple, E.B.

    1984-01-01

    The authors have previously described a system for delivery of microwave-induced hyperthermia utilizing flexible coaxial cables that are modified to serve as microwave antennas. These small (--1.6mm o.d.) antennas ae introduced into 2mm o.d. nylon catheters implanted in the tumor. This system has been further modified for use in the treatment of surgically unresectible abdominal, pelvic, and head and neck tumors. The modifications are described that were used to treat two pelvic, one upper abdominal, and one base of tongue tumor. The nylon catheters are implanted during surgery. After a short recovery period, the microwave antennas are inserted and the tumor region is heated for --1hr. The antennas are removed, iridium-192 seeds are placed in the catheters, 2800 - 5000 rad (CGy) doses are delivered, followed by a 1hr hyperthermia treatment. The temperature distributions and future applications are discussed

  12. 500 kHZ intracavitary hyperthermia in the treatment of patients with cervical and endometrial cancer - preliminary results and treatment description

    International Nuclear Information System (INIS)

    Piotrowicz, N.; Lyczek, J.; Zielinski, J.; Debicki, P.

    2002-01-01

    The effectiveness of elevated temperature (hyperthermia) in cancer treatment is a well-known issue. However, due to technical problems with generating hyperthermia within the tumour and, at the same time, sparing the healthy tissues, in practice this modality is not widely used. Local hyperthermia was induced by a computer-controlled generator (500 kHz) with three amplifiers transmitting energy to the lesion via a modified uterine brachytherapy applicator. Temperature was measured with 3 thermocouples.Total treatment time was 60-90 minutes. 10 patients with cervical and endometrial cancer were enrolled into this study and 11 procedures were performed. Prior to hyperthermia all patients were treated with external field irradiation to the pelvis to the dose of 45-46 Gy. Intracavitary LDR/HDR brachytherapy (dose of 45 Gy/point Ai n two fractions) with colpostat used for the hyperthermia procedure was than performed. In all cases, except one, caused by equipment failure, biologically stable temperature was observed. No severe side effects of treatment were observed. There was no need to terminate treatment due to high temperature intolerance. (author)

  13. Magnetic properties of the ferrimagnetic glass-ceramics for hyperthermia

    International Nuclear Information System (INIS)

    Bretcanu, O.; Verne, E.; Coeisson, M.; Tiberto, P.; Allia, P.

    2006-01-01

    Magnetic materials play a key-role in magnetic induction hyperthermia for the treatment of cancer. In this paper, we analyse the magnetic properties of ferrimagnetic glass-ceramics with the composition in the system SiO 2 -Na 2 O-CaO-P 2 O 5 -FeO-Fe 2 O 3 , as a function of the melting temperature. These materials were obtained by melting of commercial reagents in the temperature range of 1400-1550 o C. Room-temperature magnetic measurements were performed by means of a vibrating sample magnetometer at room temperature. The power loss was determined from calorimetric measurements, using a magnetic induction furnace. The highest power loss (61 W/g) has been obtained for samples melted at 1500 o C. The heat generation of the ferrimagnetic glass-ceramics prepared by two different synthesis methods (traditional melting and coprecipitation-derived) will be compared. These materials are expected to be useful in the localised treatment of cancer

  14. Multiple whole body hyperthermia treatments on normal beagles

    International Nuclear Information System (INIS)

    Geist, B.J.; Gillette, E.L.; Tucker, A.; Robertshaw, D.; Benjamin, S.A.; Macy, D.W.

    1985-01-01

    Twelve young adult male castrated beagles were randomized into either a treatment or a control group. The treatment group received 4 consecutive treatments at 1 week intertreatment intervals. A temperature and humidity controlled chamber was used to raise the core temperature to 42 0 C. Time required to raise the core temperature from 38 0 C to 42 0 C was approximately 70 minutes. Dogs were maintained at 42 0 C breathing halothane, 35% O/sub 2/ and 65 0 N/sub 2/ for 2 hours, followed by a 30 minute cool down period during which a shunt determination using 100% O/sub 2/ was done. No significant changes in temperature adjusted blood oxygen tension were noted during hyperthermia. Mean arterial blood pressure dropped an average of 15mm Hg during the 2 hour plateau. Cardiac rhythms remained stable and rates did not exceed 180 beats per minute. Central venous pressure remained stable and within normal range without treatment, 1.0 - 2.5 mm Hg. Dogs regained alertness and ambulation within 3 hours post treatment. No diarrhea was noted. The most significant acute changes appeared to be liver enzyme elevation, total protein decrement and transient changes in platelet and white blood cell counts

  15. Economic Analysis of the Reference Design for a Nuclear-Driven High-Temperature-Electrolysis Hydrogen Production Plant

    International Nuclear Information System (INIS)

    E. A. Harvego; M. G. McKellar; M. S. Sohal; J. E. O'Brien; J. S. Herring

    2008-01-01

    A reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production was developed to provide a basis for comparing the HTE concept with other hydrogen production concepts. The reference plant design is driven by a high-temperature helium-cooled reactor coupled to a direct Brayton power cycle. The reference design reactor power is 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 540 C and 900 C, respectively. The electrolysis unit used to produce hydrogen consists of 4,009,177 cells with a per-cell active area of 225 cm2. A nominal cell area-specific resistance, ASR, value of 0.4 Ohm-cm2 with a current density of 0.25 A/cm2 was used, and isothermal boundary conditions were assumed. The optimized design for the reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes an air-sweep system to remove the excess oxygen that is evolved on the anode side of the electrolyzer. The inlet air for the air-sweep system is compressed to the system operating pressure of 5.0 MPa in a four-stage compressor with intercooling. The alternating current, AC, to direct current, DC, conversion is 96%. The overall system thermal-to-hydrogen production efficiency (based on the low heating value of the produced hydrogen) is 47.12% at a hydrogen production rate of 2.356 kg/s. An economic analysis of the plant was also performed using the H2A Analysis Methodology developed by the Department of Energy (DOE) Hydrogen Program. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost using realistic financial and cost estimating assumptions. A required cost of $3.23 per kg of hydrogen produced was calculated assuming an internal rate of return of 10%. Approximately 73% of this cost ($2.36/kg) is the result of capital costs associated with

  16. Self-regulated magnetic fluid hyperthermia: A potential cancer therapy

    Science.gov (United States)

    Bagaria, Hitesh Ghanshyam

    An emerging cancer therapy, self-regulated magnetic fluid hyperthermia (MFH), is the motivation for this work. In this therapy, cancer is annihilated by heating the tumor to desired therapeutic temperatures (˜45°C) by using magnetic nanoparticles of controlled Curie temperatures (Tc). This work was aimed at preparing and characterizing FePt, NiPd and NiPt nanoparticles for self-regulated MFH because their Tc could be tuned by changing their composition. Based on the excellent colloidal stability, size tunability and toxicity considerations, FePt was an obvious choice for self-regulated MFH. The 3.2 nm Fe61Pt39 particles displayed a Tc of 151°C, which is well below the Tc of bulk Fe61Pt39 (˜327°C). To reach the desired Tc of 45°C the composition of iron needs to be increased. However, a major obstacle was the formation of iron oxide shells with increase in iron composition of the particles. A recent finding that the composition of individual FePt particles deviated significantly from the average value encouraged us to study the mechanism of formation of FePt particles. Our analysis showed that early in the reaction the particles were Pt-rich and as the reaction proceeded the Fe content increased. It was found that the wide distribution in the composition of individual particles started early in the synthesis, suggesting that the compositional variability may be attributed to the Pt nuclei. The synthesized FePt particles are unsuitable for biological applications because of their hydrophobic surface. Hence, their surface was modified by ligand exchange with mercapto alkanoic acids. After ligand exchange, stable FePt dispersions could be formed in alkaline water. The study revealed that both the carboxylate and thiol groups were required to form stable FePt dispersions. In addition, 15 nm gold particles were successfully conjugated to genetically modified adenoviruses that selectively bind to cancer tumors. We also modeled the thermal transport in tissues during

  17. Magnetic Resonance–Guided High-Intensity Focused Ultrasound Hyperthermia for Recurrent Rectal Cancer: MR Thermometry Evaluation and Preclinical Validation

    Energy Technology Data Exchange (ETDEWEB)

    Chu, William, E-mail: William.Chu@sunnybrook.ca [Department of Radiation Oncology, Sunnybrook Health Sciences Centre and the University of Toronto, Toronto, Ontario (Canada); Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario (Canada); Staruch, Robert M. [Clinical Sites Research Program, Philips Research, Cambridge, Massachusetts (United States); Pichardo, Samuel [Thunder Bay Regional Research Institute, Thunder Bay, Ontario (Canada); Physics and Electrical Engineering, Lakehead University, Thunder Bay, Ontario (Canada); Tillander, Matti; Köhler, Max O. [MR Therapy, Philips Healthcare, Vantaa (Finland); Huang, Yuexi [Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario (Canada); Ylihautala, Mika [MR Therapy, Philips Healthcare, Vantaa (Finland); McGuffin, Merrylee [Department of Radiation Oncology, Sunnybrook Health Sciences Centre and the University of Toronto, Toronto, Ontario (Canada); Czarnota, Gregory [Department of Radiation Oncology, Sunnybrook Health Sciences Centre and the University of Toronto, Toronto, Ontario (Canada); Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario (Canada); Hynynen, Kullervo [Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario (Canada)

    2016-07-15

    Purpose: To evaluate the feasibility of magnetic resonance–guided high-intensity focused ultrasound (MR-HIFU) mild hyperthermia in deep tissue targets for enhancing radiation therapy and chemotherapy in the context of recurrent rectal cancer. A preclinical study was performed to evaluate the safety and performance of MR-HIFU mild hyperthermia. A prospective imaging study was performed in volunteers with rectal cancer to evaluate MR thermometry quality near the rectum and accessibility of rectal tumors using MR-HIFU. Methods and Materials: Mild hyperthermia was performed in pig thigh (9 sonications, 6 pigs) using a clinical MR-HIFU system. Targets near the rectal wall and deep thigh were evaluated. Thermal maps obtained in 6 planes every 3.2 seconds were used to control sonications in 18-mm diameter treatment regions at temperatures of 42°C to 42.5°C for 10 to 60 minutes. Volunteer imaging-only studies to assess the quality of MR thermometry (without heating) were approved by the institutional research ethics board. Anatomic and MR thermometry images were acquired in consenting volunteers with rectal cancer. In 3 of 6 study participants, rectal filling with saline was used to reduce motion-related MR thermometry artifacts near the tumor. Results: In pigs, mean target temperature matched the desired hyperthermia temperature within 0.2°C; temporal standard deviation ≤0.5°C. With optimized control thresholds, no undesired tissue damage was observed. In human volunteers, MR temperature measurements had adequate precision and stability, especially when rectal filling was used to reduce bowel motion. Conclusions: In pigs, MR-HIFU can safely deliver mild hyperthermia (41°C-43°C) to a targeted volume for 30 minutes. In humans, careful patient selection and preparation will enable adequate targeting for recurrent rectal cancers and sufficient MR temperature mapping stability to control mild hyperthermia. These results enable human trials of MR-HIFU hyperthermia.

  18. Magnetic Resonance–Guided High-Intensity Focused Ultrasound Hyperthermia for Recurrent Rectal Cancer: MR Thermometry Evaluation and Preclinical Validation

    International Nuclear Information System (INIS)

    Chu, William; Staruch, Robert M.; Pichardo, Samuel; Tillander, Matti; Köhler, Max O.; Huang, Yuexi; Ylihautala, Mika; McGuffin, Merrylee; Czarnota, Gregory; Hynynen, Kullervo

    2016-01-01

    Purpose: To evaluate the feasibility of magnetic resonance–guided high-intensity focused ultrasound (MR-HIFU) mild hyperthermia in deep tissue targets for enhancing radiation therapy and chemotherapy in the context of recurrent rectal cancer. A preclinical study was performed to evaluate the safety and performance of MR-HIFU mild hyperthermia. A prospective imaging study was performed in volunteers with rectal cancer to evaluate MR thermometry quality near the rectum and accessibility of rectal tumors using MR-HIFU. Methods and Materials: Mild hyperthermia was performed in pig thigh (9 sonications, 6 pigs) using a clinical MR-HIFU system. Targets near the rectal wall and deep thigh were evaluated. Thermal maps obtained in 6 planes every 3.2 seconds were used to control sonications in 18-mm diameter treatment regions at temperatures of 42°C to 42.5°C for 10 to 60 minutes. Volunteer imaging-only studies to assess the quality of MR thermometry (without heating) were approved by the institutional research ethics board. Anatomic and MR thermometry images were acquired in consenting volunteers with rectal cancer. In 3 of 6 study participants, rectal filling with saline was used to reduce motion-related MR thermometry artifacts near the tumor. Results: In pigs, mean target temperature matched the desired hyperthermia temperature within 0.2°C; temporal standard deviation ≤0.5°C. With optimized control thresholds, no undesired tissue damage was observed. In human volunteers, MR temperature measurements had adequate precision and stability, especially when rectal filling was used to reduce bowel motion. Conclusions: In pigs, MR-HIFU can safely deliver mild hyperthermia (41°C-43°C) to a targeted volume for 30 minutes. In humans, careful patient selection and preparation will enable adequate targeting for recurrent rectal cancers and sufficient MR temperature mapping stability to control mild hyperthermia. These results enable human trials of MR-HIFU hyperthermia.

  19. Hyperthermia-induced disruption of functional connectivity in the human brain network.

    Directory of Open Access Journals (Sweden)

    Gang Sun

    Full Text Available BACKGROUND: Passive hyperthermia is a potential risk factor to human cognitive performance and work behavior in many extreme work environments. Previous studies have demonstrated significant effects of passive hyperthermia on human cognitive performance and work behavior. However, there is a lack of a clear understanding of the exact affected brain regions and inter-regional connectivities. METHODOLOGY AND PRINCIPAL FINDINGS: We simulated 1 hour environmental heat exposure to thirty-six participants under two environmental temperature conditions (25 °C and 50 °C, and collected resting-state functional brain activity. The functional connectivities with a preselected region of interest (ROI in the posterior cingulate cortex and precuneus (PCC/PCu, furthermore, inter-regional connectivities throughout the entire brain using a prior Anatomical Automatic Labeling (AAL atlas were calculated. We identified decreased correlations of a set of regions with the PCC/PCu, including the medial orbitofrontal cortex (mOFC and bilateral medial temporal cortex, as well as increased correlations with the partial orbitofrontal cortex particularly in the bilateral orbital superior frontal gyrus. Compared with the normal control (NC group, the hyperthermia (HT group showed 65 disturbed functional connectivities with 50 of them being decreased and 15 of them being increased. While the decreased correlations mainly involved with the mOFC, temporal lobe and occipital lobe, increased correlations were mainly located within the limbic system. In consideration of physiological system changes, we explored the correlations of the number of significantly altered inter-regional connectivities with differential rectal temperatures and weight loss, but failed to obtain significant correlations. More importantly, during the attention network test (ANT we found that the number of significantly altered functional connectivities was positively correlated with an increase in

  20. Trial of radiation therapy combined with hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Takegawa, Y; Fujiwara, K; Oe, J; Nagase, M; Akiyama, H [Tokushima Univ. (Japan). School of Medicine

    1978-08-01

    Nine patients were treated by the combination therapy of external irradiation and hyperthermia, 5 patients with metastatic lesions; two breast cancer, one lung cancer, one malignant melanoma, one vulva cancer, 1 patient with recurrent lesion of skin cancer and 3 patients with bladder cancer. All patients were treated by heating locally (42/sup 0/C, 30 min) followed by external irradiation with 4,000 - 5,000 rad over 4 to 5 weeks. No local recurrence was found in 4 of 9 patients.

  1. Reduction of hyperthermia in pediatric patients with severe traumatic brain injury: a quality improvement initiative.

    Science.gov (United States)

    Lovett, Marlina E; Moore-Clingenpeel, Melissa; Ayad, Onsy; O'Brien, Nicole

    2018-02-01

    OBJECTIVE Severe traumatic brain injury remains a leading cause of morbidity and mortality in the pediatric population. Providers focus on reducing secondary brain injury by avoiding hypoxemia, avoiding hypotension, providing normoventilation, treating intracranial hypertension, and reducing cerebral metabolic demand. Hyperthermia is frequently present in patients with severe traumatic brain injury, contributes to cerebral metabolic demand, and is associated with prolonged hospital admission as well as impaired neurological outcome. The objective of this quality improvement initiative was to reduce the duration of hyperthermia for pediatric patients with severe traumatic brain injury during the initial 72 hours of admission to the pediatric intensive care unit. METHODS A retrospective chart review was performed to evaluate the incidence and duration of hyperthermia within a preintervention cohort. The retrospective phase was followed by three 6-month intervention periods (intervention Phase 1, the maintenance phase, and intervention Phase 2). Intervention Phase 1 entailed placement of a cooling blanket on the bed prior to patient arrival and turning it on once the patient's temperature rose above normothermia. The maintenance phase focused on sustaining the results of Phase 1. Intervention Phase 2 focused on total prevention of hyperthermia by initiating cooling blanket use immediately upon patient arrival to the intensive care unit. RESULTS The median hyperthermia duration in the preintervention cohort (n = 47) was 135 minutes. This was reduced in the Phase 1 cohort (n = 9) to 45 minutes, increased in the maintenance phase cohort (n = 6) to 88.5 minutes, and decreased again in the Phase 2 cohort (n = 9) to a median value of 0 minutes. Eight percent of patients in the intervention cohorts required additional sedation to tolerate the cooling blanket. Eight percent of patients in the intervention cohorts became briefly hypothermic while on the cooling blanket. No

  2. Inhibition by hyperthermia of repair synthesis and chromatin reassembly of ultraviolet-induced damage to DNA

    International Nuclear Information System (INIS)

    Bodell, W.J.; Cleaver, J.E.; Roti Roti, J.L.

    1984-01-01

    The authors have investigated the effects of hyperthermia treatment on sequential steps of the repair of UV-induced DNA damage in HeLa cells. DNA repair synthesis was inhibited by 40% after 15 min of hyperthermia treatment at 45 0 C; greater inhibition of repair synthesis occurred with prolonged incubation at 45 0 C. Enzymatic digestion of repair-labeled DNA with Exonuclease III indicated that once DNA repair was initiated, the DNA repair patch was synthesized to completion and that ligation of the DNA repair patch occurred. Thus, the observed inhibition of UV-induced DNA repair synthesis by hyperthermia treatment may be the result of inhibition of enzymes involved in the initiating steps(s) of DNA repair. DNA repair patches synthesized in UV-irradiated cells labeled at 37 0 C with[ 3 H]Thd were 2.2-fold more sensitive to micrococcal nuclease digestion than was parental DNA; if the length of the labeling period was prolonged, the nuclease sensitivity of the repair patch synthesized approached that of the parental DNA. DNA repair patches synthesized at 45 0 C, however, remained sensitive to micrococcal nuclease digestion even after long labeling periods, indicating that heat treatment inhibits the reassembly of the DNA repair patch into nucleosomal structures. 23 references, 3 figures, 2 tables

  3. The study of thermal change by chemoport in radiofrequency hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Hoon; Lee, Sun Young; Gim, Yang Soo; Kwak, Keun Tak; Yang, Myung Sik; Cha, Seok Yong [Dept. of Radiation Oncology, Chonbuk National University Hospital, Jeonju (Korea, Republic of)

    2015-12-15

    This study evaluate the thermal changes caused by use of the chemoport for drug administration and blood sampling during radiofrequency hyperthermia. 20 cm size of the electrode radio frequency hyperthermia (EHY-2000, Oncotherm KFT, Hungary) was used. The materials of the chemoport in our hospital from currently being used therapy are plastics, metal-containing epoxy and titanium that were made of the diameter 20 cm, height 20 cm insertion of the self-made cylindrical Agar phantom to measure the temperature. Thermoscope(TM-100, Oncotherm Kft, Hungary) and Sim4Life (Ver2.0, Zurich, Switzerland) was compared to the actual measured temperature. Each of the electrode measurement position is the central axis and the central axis side 1.5 cm, 0 cm(surface), 0.5 cm, 1.8 cm, 2.8 cm in depth was respectively measured. The measured temperature is 24.5 - 25.5℃, humidity is 30% - 32%. In five-minute intervals to measure the output power of 100 W, 60 min. In the electrode central axis 2.8 cm depth, the maximum temperature of the case with the unused of the chemoport, plastic, epoxy and titanium were respectively 39.51℃, 39.11℃, 38.81℃, 40.64℃, simulated experimental data were 42.20 ℃, 41.50℃, 40.70℃, 42.50℃. And in the central axis electrode side 1.5 cm depth 2.8 cm, measured data were 39.37℃, 39.32℃, 39.20℃, 39.46℃, the simulated experimental data were 42.00℃, 41.80℃, 41.20℃, 42.30℃. The thermal variations were caused by radiofrequency electromagnetic field surrounding the chemoport showed lower than in the case of unused in non-conductive plastic material and epoxy material, the titanum chemoport that made of conductor materials showed a slight differences. This is due to the metal contents in the chemoport and the geometry of the chemoport. And because it uses a low radio frequency bandwidth of the used equipment. That is, although use of the chemoport in this study do not significantly affect the surrounding tissue. That is, because the

  4. The study of thermal change by chemoport in radiofrequency hyperthermia

    International Nuclear Information System (INIS)

    Lee, Seung Hoon; Lee, Sun Young; Gim, Yang Soo; Kwak, Keun Tak; Yang, Myung Sik; Cha, Seok Yong

    2015-01-01

    This study evaluate the thermal changes caused by use of the chemoport for drug administration and blood sampling during radiofrequency hyperthermia. 20 cm size of the electrode radio frequency hyperthermia (EHY-2000, Oncotherm KFT, Hungary) was used. The materials of the chemoport in our hospital from currently being used therapy are plastics, metal-containing epoxy and titanium that were made of the diameter 20 cm, height 20 cm insertion of the self-made cylindrical Agar phantom to measure the temperature. Thermoscope(TM-100, Oncotherm Kft, Hungary) and Sim4Life (Ver2.0, Zurich, Switzerland) was compared to the actual measured temperature. Each of the electrode measurement position is the central axis and the central axis side 1.5 cm, 0 cm(surface), 0.5 cm, 1.8 cm, 2.8 cm in depth was respectively measured. The measured temperature is 24.5 - 25.5℃, humidity is 30% - 32%. In five-minute intervals to measure the output power of 100 W, 60 min. In the electrode central axis 2.8 cm depth, the maximum temperature of the case with the unused of the chemoport, plastic, epoxy and titanium were respectively 39.51℃, 39.11℃, 38.81℃, 40.64℃, simulated experimental data were 42.20 ℃, 41.50℃, 40.70℃, 42.50℃. And in the central axis electrode side 1.5 cm depth 2.8 cm, measured data were 39.37℃, 39.32℃, 39.20℃, 39.46℃, the simulated experimental data were 42.00℃, 41.80℃, 41.20℃, 42.30℃. The thermal variations were caused by radiofrequency electromagnetic field surrounding the chemoport showed lower than in the case of unused in non-conductive plastic material and epoxy material, the titanum chemoport that made of conductor materials showed a slight differences. This is due to the metal contents in the chemoport and the geometry of the chemoport. And because it uses a low radio frequency bandwidth of the used equipment. That is, although use of the chemoport in this study do not significantly affect the surrounding tissue. That is, because the

  5. Microprocessor-controlled Nd:YAG laser for hyperthermia induction in the RIF-1 tumor.

    Science.gov (United States)

    Waldow, S M; Russell, G E; Wallner, P E

    1992-01-01

    Near-infrared radiation from a Nd:YAG laser at 1,064 nm was used interstitially or superficially to induce hyperthermia in RIF-1 tumors in C3H male mice. A single 600-microns quartz fiber with a 0.5-cm cylindrical diffusor or a weakly diverging microlens at its distal end was used to deliver laser energy to tumors in the hind leg (mean volume = 100 mm3). Two thermocouples were inserted into each tumor. One thermocouple controlled a microprocessor-driven hyperthermia program (maximum output of 3.5 Watts) to maintain the desired temperature. Tumors were exposed to various temperature-time combinations (42-45 degrees C/30 min). Our initial results indicated that excellent temperature control to within 0.2 degrees C of the desired temperature at the feedback thermocouple was achievable during both superficial and interstitial heat treatments. Temperatures at the second thermocouple, however, were found to be lower by as much as 2.3 degrees C (using the cylindrical diffusor) or higher by up to 4.6 degrees C (using the microlens) when compared to the feedback thermocouple temperature. Several correlations were seen between total dose, tumor growth delay, percent skin necrosis, and temperature at the second thermocouple after several superficial and interstitial treatments. Statistically significant improvements in tumor growth delay (at 42 and 45 degrees C) and increased percent skin necrosis at all temperatures were observed after superficial versus interstitial treatment.

  6. Selective heating of soft tissue-bone interfaces during scanned focussed ultrasound hyperthermia

    International Nuclear Information System (INIS)

    Hynynen, K.; De Young, D.; Roemer, R.; Kundrat, M.

    1987-01-01

    Bone heating has been a frequent problem with clinical hyperthermia treatments induced by plane ultrasonic transducers. In this study, detailed temperature distributions were measured in dogs' (5 dogs) thigh muscles and bone in vivo while focussed ultrasound was applied to elevate the muscle temperature next to the bone. Significantly higher temperature elevations were measured at the bone surface than in the target volume in front of the bone. The temperature distribution was sharp decreasing fast inside the bone and also in front of it. By using more sharply focussed and multiple beams the temperature elevation at the bone surface was reduced and by suitable choice of the distance between the bone surface and the acoustical focus almost uniform temperature could be induced in the overlying muscle tissue from the surface down to the bone - the bone surface being in the same temperature as the muscle. Similar result was obtained by using single, higher frequency focussed beam (3.58 MHz). Also the utilization of nonlinear ultrasonic propagation appeared to reduce bone heating. The results showed that by carefully planning ultrasound hyperthermia treatments, tissues close to bone can be heated without extensive temperature elevation at bone surface

  7. JSA guideline for the management of malignant hyperthermia crisis 2016.

    Science.gov (United States)

    2017-04-01

    Malignant hyperthermia (MH) can be fatal if the crisis is not appropriately treated. It is an inherited disease usually triggered by the administration of volatile inhalational anesthetics and/or succinylcholine, a muscle relaxant. In a patient with suspected MH, the mechanism of calcium release from storage in the sarcoplasmic reticulum in the skeletal muscle is abnormally accelerated. Unexplained hypercarbia representing >55 mmHg of end-tidal carbon dioxide, tachycardia, and muscle rigidity (including masseter muscle rigidity) are early signs of the initiation of MH, because the metabolism is accelerated. The body temperature can rise by >0.5 °C/15 min and may reach ≥40 °C. Respiratory and metabolic acidosis, arrhythmia, cola-colored urine, increased levels of serum potassium, and tented T-waves on electrocardiogram are common and can lead to cardiac arrest. MH should be treated by discontinuation of the triggering agents, administration of intravenous dantrolene (initially 1 mg/kg), and reduction of the body temperature. Early diagnosis and sufficient dantrolene with body temperature reduction are essential to relieve the patient's MH crisis. This guideline in Japanese translation has been posted on the website: http://www.anesth.or.jp/guide/pdf/guideline_akuseikounetsu.pdf .

  8. Membrane defect in procine malignant hyperthermia

    International Nuclear Information System (INIS)

    O'Brien, P.J.

    1985-01-01

    Malignant hyperthermia (MH) has been proposed to result from abnormal calcium-homeostasis in skeletal muscle. This study tested the hypothesis that calcium-sequestration or calcium-release by sarcoplasmic reticulum was abnormal in MH-susceptible swine. A heavy sarcoplasmic reticulum fraction (HSR), enriched in terminal cisternae, was isolated from MH and control muscle using differential and density-gradient centrifugation. Calcium transport was studied using 45 Ca radioisotope and Millipore filtration. Enzymatic activities, cholesterol, phospholipid, and protein composition were determined using spectrophotometric techniques and polyacrylamide gel electrophoresis. Properties of calcium-sequestration by MH and control HSR were indistinguishable, although Ca 2+ -ATPase and calsequestrin content were 100% increased in MH HSR. However when muscle homogenate pH was decreased due to MH, calcium-uptake activity was depressed to <5% of control values. Results of this study indicate a model for the etiopathogenesis of MH, and for the inheritance and diagnosis of susceptibility to MH. Malignant hyperthermia is initiated due to a hypersensitive HSR calcium-release mechanism and propagated by a loss of calcium-sequestering function as acidosis develops. Susceptibility is inherited in an autosomal, codominant pattern and may be diagnosed most definitively and sensitively on the basis of calcium-release sensitivity-tests, performed on isolated HSR

  9. Heating efficiency in magnetic nanoparticle hyperthermia

    International Nuclear Information System (INIS)

    Deatsch, Alison E.; Evans, Benjamin A.

    2014-01-01

    Magnetic nanoparticles for hyperthermic treatment of cancers have gained significant attention in recent years. In magnetic hyperthermia, three independent mechanisms result in thermal energy upon stimulation: Néel relaxation, Brownian relaxation, and hysteresis loss. The relative contribution of each is strongly dependent on size, shape, crystalline anisotropy, and degree of aggregation or agglomeration of the nanoparticles. We review the effects of each of these physical mechanisms in light of recent experimental studies and suggest routes for progress in the field. Particular attention is given to the influence of the collective behaviors of nanoparticles in suspension. A number of recent studies have probed the effect of nanoparticle concentration on heating efficiency and have reported superficially contradictory results. We contextualize these studies and show that they consistently indicate a decrease in magnetic relaxation time with increasing nanoparticle concentration, in both Brownian- and Néel-dominated regimes. This leads to a predictable effect on heating efficiency and alleviates a significant source of confusion within the field. - Highlights: • Magnetic nanoparticle hyperthermia. • Heating depends on individual properties and collective properties. • We review recent studies with respect to loss mechanisms. • Collective behavior is a key source of confusion in the field. • We contextualize recent studies to elucidate consistencies and alleviate confusion

  10. New experimental model for single liver lobe hyperthermia in small animals using non-directional microwaves.

    Directory of Open Access Journals (Sweden)

    Ionuț Tudorancea

    Full Text Available Our aim was to develop a new experimental model for in vivo hyperthermia using non-directional microwaves, applicable to small experimental animals. We present an affordable approach for targeted microwave heat delivery to an isolated liver lobe in rat, which allows rapid, precise and stable tissue temperature control.A new experimental model is proposed. We used a commercial available magnetron generating 2450 MHz, with 4.4V and 14A in the filament and 4500V anodic voltage. Modifications were required in order to adjust tissue heating such as to prevent overheating and to allow for fine adjustments according to real-time target temperature. The heating is controlled using a virtual instrument application implemented in LabView® and responds to 0.1° C variations in the target. Ten healthy adult male Wistar rats, weighing 250-270 g were used in this study. The middle liver lobe was the target for controlled heating, while the rest of the living animal was protected.In vivo microwave delivery using our experimental setting is safe for the animals. Target tissue temperature rises from 30°C to 40°C with 3.375°C / second (R2 = 0.9551, while the increment is lower it the next two intervals (40-42°C and 42-44°C with 0.291°C/ s (R2 = 0.9337 and 0.136°C/ s (R2 = 0.7894 respectively, when testing in sequences. After reaching the desired temperature, controlled microwave delivery insures a very stable temperature during the experiments.We have developed an inexpensive and easy to manufacture system for targeted hyperthermia using non-directional microwave radiation. This system allows for fine and stable temperature adjustments within the target tissue and is ideal for experimental models testing below or above threshold hyperthermia.

  11. A system for the treatment of cancer by magnetically mediated arterial embolisation hyperthermia

    International Nuclear Information System (INIS)

    Jones, S.; Moroz, P.

    2002-01-01

    Full text: Sirtex Medical Limited is developing new technology to treat cancer by induced hyperthermia. A wealth of scientific data from laboratory and animal experimentation has shown that if the temperature of cancerous tissue is maintained for some time above about 42 deg C then that cancer will be destroyed. In current clinical practice, hyperthermia therapy is mostly used as an adjunct to radiotherapy in the treatment of superficial and other easily accessible tumour sites. Restrictions to the wider application of hyperthermia to the treatment of tumours located at deep body sites are technological in nature. There are presently no reliable non-invasive techniques that can be used to deliver an adequate heat dose to a deep seated tumour in an organ such as the liver without risking unacceptable heating of overlying and surrounding normal tissue. The Sirtex technology uses the heat generated in small magnetic particles when exposed to a high frequency magnetic field. The particles are delivered to the tumour via arterially infused microspheres which eventually embolise the tumour vasculature. The enhanced concentration of microspheres around the tumour ensures only the diseased tissue is heated. This paper reviews the current status of this research and presents recent experimental results including the differential heating and consequent destruction of experimental animal tumours. The pathway to clinical application will be discussed in light of these results

  12. A Parallel 2D Numerical Simulation of Tumor Cells Necrosis by Local Hyperthermia

    International Nuclear Information System (INIS)

    Reis, R F; Loureiro, F S; Lobosco, M

    2014-01-01

    Hyperthermia has been widely used in cancer treatment to destroy tumors. The main idea of the hyperthermia is to heat a specific region like a tumor so that above a threshold temperature the tumor cells are destroyed. This can be accomplished by many heat supply techniques and the use of magnetic nanoparticles that generate heat when an alternating magnetic field is applied has emerged as a promise technique. In the present paper, the Pennes bioheat transfer equation is adopted to model the thermal tumor ablation in the context of magnetic nanoparticles. Numerical simulations are carried out considering different injection sites for the nanoparticles in an attempt to achieve better hyperthermia conditions. Explicit finite difference method is employed to solve the equations. However, a large amount of computation is required for this purpose. Therefore, this work also presents an initial attempt to improve performance using OpenMP, a parallel programming API. Experimental results were quite encouraging: speedups around 35 were obtained on a 64-core machine

  13. Pathological changes in the rabbit lungs after irradiation and after combined irradiation and hyperthermia

    International Nuclear Information System (INIS)

    Zinner, M.

    1984-01-01

    The effects of combined irradiation and hyperthermia and of irradiation alone on normal lung tissue was investigated in rabbits. The animals of both therapy groups were irradiated with 2 Gy five times a week for a 6-week period. The animals of group 1 were additionally exposed to hyperthermia 3 times a week after irradiation. The method applied was the condenser field method (25 to 35 Watt/min). Only the right lung was treated in all animals. The animals were sacrificed 3 months after termination of the therapy, and large-surface lung sections were prepared. The following results were obtained: There is a quantifiable difference in the severeness of fibrosis between groups 1 and 2. Fibrosis was more pronounced in group 1 but the difference was not statistically significant. In both groups, fibrosis was unevenly distributed in the different lung areas. Fibrosis was highest in the ventral and apical regions. These were the regions where the highest local temperature rise was recorded during hyperthermia and where the highest local radiation dose was applied. Histologically, signs of acute inflammatory processes were observed in both groups in parallel to regeneration and repair processes involving neogenesis. (orig./MG) [de

  14. Verification of hyperthermia treatment planning in cervix carcinoma patients using invasive thermometry

    International Nuclear Information System (INIS)

    Haaren Van, P.M.A.; Kok, H.P.; Zum Voerde Sive Voerding, P.J.; Oldenborg, S.; Stalpers, L.J.A.; Crezee, J.; Berg Van den, C.A.T; Leeuw De, A.A.C.

    2005-01-01

    Full text: Hyperthermia treatment planning (HTP) is a useful tool for improvement of clinical hyperthermia treatments. Aim of this study was to determine the correlation between HTP and measurements during hyperthermia treatments. We compared the calculated specific absorption rate (SAR) with clinically measured SAR-values, from ΔT-measurements, in cervix carcinoma patients. General difficulties for such clinical verifications are changes in the anatomy during the different steps and possible movement of the catheters. We used one fixed invasive catheter in the tumor additional to the usual non-invasive catheters in the vagina, bladder and rectum, for insertion of multisensor thermocouple probes. A special CT-scan with the patient in treatment position and the catheters in situ was made for the HTP. We performed these verifications in a total of 11 treatments in 7 patients. The main difficulties for accurate verification were of clinical nature: difficulties arising from the use of gynaecological tampon and the limited number of measurements in tissue. Remaining air in the vagina and sub-optimal tissue contact of the catheters resulted in bad thermal contact between thermocouples and tissue, causing measurement artefacts that are difficult to correlate with calculations. These artefacts are probably not specific for thermocouple measurements, but more general for intraluminal temperature and SAR measurements. (author)

  15. Effect of prior hyperthermia on subsequent thermal enhancement of radiation damage in mouse intestine

    International Nuclear Information System (INIS)

    Marigold, J.C.L.; Hume, S.P.

    1982-01-01

    Hyperthermia given in conjunction with X-rays results in a greater level of radiation injury than following X-rays alone, giving a thermal enhancement ratio (TER). The effect of prior hyperthermia ('priming') on TER was studied in the small intestine of mouse by giving 42.0 deg C for 1 hour at various times before the combined heat and X-ray treatments. Radiation damage was assessed by measuring crypt survival 4 days after radiation. TER was reduced when 'priming' hyperthermia was given 24-48 hours before the combined treatments. The reduction in effectiveness of the second heat treatment corresponded to a reduction in hyperthermal temperature of approximately 0.5 deg C, a value similar to that previously reported for induced resistance to heat given alone ('thermotolerance') (Hume and Marigold 1980). However, the time courses for development and decay of the TER response were much longer than those for 'thermotolerance', suggesting that different mechanisms are involved in thermal damage following heat alone and thermal enhancement of radiation damage

  16. Effect of hyperthermia on blood flow in VX2 tumor transplanted in rabbit

    International Nuclear Information System (INIS)

    Arita, Takeshi

    1994-01-01

    Effect of hyperthermia on blood flow was evaluated using VX 2 rabbit carcinoma in both legs. Microwave energy at 2450 MHz was used to heat tumors for 40 minutes. An outer canula of 18 G Erasta was implanted in the depth of 2 cm in tumor to measure the temperature and to maintain at 43.0degC-44.0degC. The blood flow in tumors was evaluated by color doppler flow imaging and dynamic MRI. Disturbance of blood flow in the depth of surface 0 cm to 2 cm in tumors was showed at 10 minutes starting 43.0degC heating and at almost all sites disappearance of blood flow was showed at 40 minutes using color doppler flow imaging. But the blood flow beyond the depth of 2 cm was not so disturbed at 40 minutes, relatively. After hyperthermia T1WI and T2WI in heated tumor were no difference comparing with those in control tumor, but heated tumor showed no enhancement using dynamic MRI with TURBO-FLASH technique and post-enhanced T1WI. Histologically, there was extensive tumor necrosis and thrombus formation in heated tumor after 3 days and 1 week. Therefore color doppler flow imaging and dynamic MRI were considered to be useful for evaluation of blood flow in tumor after and during hyperthermia. (author)

  17. Magnetic fluid hyperthermia probed by both calorimetric and dynamic hysteresis measurements

    Energy Technology Data Exchange (ETDEWEB)

    Guibert, Clément; Fresnais, Jérôme; Peyre, Véronique; Dupuis, Vincent, E-mail: vincent.dupuis@upmc.fr

    2017-01-01

    In this paper, we report an investigation of magnetic fluid hyperthermia (MFH) using combined calorimetric and newly implemented dynamic hysteresis measurements for two sets of well characterized size-sorted maghemite nanoparticles (with diameters of about 10 nm and 20 nm) dispersed in water and in glycerol. Our primary goal was to assess the influence of viscosity on the heating efficiency of magnetic nanoparticles described in terms of specific loss power (SLP or specific absorption rate, SAR) and dynamic hysteresis. In particular, we aimed to investigate how this SLP depends on the transition from Néelian to Brownian behavior of nanoparticles expected to occur between 10 nm and 20 nm (for maghemite) and dependent on the viscosity. While we observed a good agreement between calorimetric and dynamic hysteresis measurements, we found that the SLP measured for the different systems do not depend noticeably on the viscosity of solvent. Calculations performed according to Rosensweig's linear model [1] allow us to quantitatively reproduce our results at low field intensities, provided we use a value for the magnetic anisotropy constant much smaller than the one commonly used in the literature. This raises the question of the temperature dependance of the magnetic anisotropy constant and its relevance for a quantitative description of MFH. - Highlights: • Dynamic hysteresis measurements are a promising tool to study magnetic hyperthermia. • Dynamic hysteresis cycles can be reproduced using a simple model. • The effect of viscosity on hyperthermia of maghemite is weaker than expected.

  18. Hyperthermia effects in the presence of gold nanoparticles together with chemotherapy on Saos-2 cell line

    International Nuclear Information System (INIS)

    Sazgarnia, A.; Bahreyni Toosi, M. H.; Haji Ghahremani, F.; Rajabi, O.; Aledavood, A.; Esmaily, H.

    2011-01-01

    Hyperthermia created by microwave, infrared, ultrasound and other methods, is often utilized as an adjuvant to sensitize cancer cells to the effects of chemotherapy and radiation therapy. We investigated the efficacy of hyperthermia using microwave in synergy with chemotherapy in the presence and absence and gold nanoparticles. Material and Methods: After culturing and proliferation of the Saos-2 cell line derived from human osteogenic sarcoma, the cells were incubated at two concentrations of gold nanoparticles in two diameters of 20 and 40 nm and in the absence and presence of doxorubicin in different groups. Forty eight hours after irradiating the cells with microwave up to a temperature of 42 d egree C , cell survival rate was determined using the MTT method, in order to study the effectiveness of the therapeutic parameters. Results: Cell survival in the presence of gold nanoparticles was greater than 95%. After chemotherapy by doxorubicin with and without 40 nm gold nanoparticles, cell survival rates were determined as 62.8% and 37.1 %, declining down to 17% and 4.1% respectively following the combined treatment with microwave and chemotherapy in the presence of 20 and 40 nm gold nanoparticles. Discussion and Conclusions: Gold nanoparticles did not induce any cytotoxicity by themselves; their presence along with microwave provided a reduction in survival rate that was comparable in severity with the lethal effects of doxorubicin. microwave hyperthermia with gold nanoparticles produced a higher treatment efficiency in comparison to similar groups in which gold nanoparticles were absent. The synergism observed between hyperthermia and chemotherapy was dependent in gold nanoparticles' size and concentration. This finding could be caused by increased uptake of doxorubicin by the cells in the presence of gold nanoparticles.

  19. Targeting to carcinoma cells with chitosan- and starch-coated magnetic nanoparticles for magnetic hyperthermia.

    Science.gov (United States)

    Kim, Dong-Hyun; Kim, Kyoung-Nam; Kim, Kwang-Mahn; Lee, Yong-Keun

    2009-01-01

    The delivery of hyperthermic thermoseeds to a specific target site with minimal side effects is an important challenge in targeted hyperthermia, which employs magnetic method and functional polymers. An external magnetic field is used to control the site-specific targeting of the magnetic nanoparticles. Polymer-coated magnetic nanoparticles can confer a higher affinity to the biological cell membranes. In this study, uncoated, chitosan-coated, and starch-coated magnetic nanoparticles were synthesized for use as a hyperthermic thermoseed. Each sample was examined with respect to their applications to hyperthermia using XRD, VSM, and FTIR. In addition, the temperature changes under an alternating magnetic field were observed. As in vitro tests, the magnetic responsiveness of chitosan- and starch-coated magnetite was determined by a simple blood vessel model under various intensities of magnetic field. L929 normal cells and KB carcinoma cells were used to examine the cytotoxicity and affinity of each sample using the MTT method. The chitosan-coated magnetic nanoparticles generated a higher DeltaT of 23 degrees C under an AC magnetic field than the starch-coated magnetite, and the capturing rate of the particles was 96% under an external magnetic field of 0.4 T. The highest viability of L929 cells was 93.7%. Comparing the rate of KB cells capture with the rate of L929 cells capture, the rate of KB cells capture relatively increased with 10.8% in chitosan-coated magnetic nanoparticles. Hence, chitosan-coated magnetic nanoparticles are biocompatible and have a selective affinity to KB cells. The targeting of magnetic nanoparticles in hyperthermia was improved using a controlled magnetic field and a chitosan-coating. Therefore, chitosan-coated magnetic nanoparticles are expected to be promising materials for use in magnetic targeted hyperthermia. 2008 Wiley Periodicals, Inc.

  20. Preparation and characterization of composite microspheres for brachytherapy and hyperthermia treatment of cancer

    International Nuclear Information System (INIS)

    Zhao Di; Huang Wenhai; Rahaman, Mohamed N.; Day, Delbert E.; Wang Deping; Gu Yifei

    2012-01-01

    Composite microspheres were prepared by coating yttrium–aluminum–silicate (YAS) glass microspheres (20–30 μm) with a layer of Fe 3 O 4 nanoparticles and evaluated for potential use in brachytherapy and hyperthermia treatment of cancer. After neutron activation to form the β-emitting 90 Y radionuclide, the composite microspheres can be injected into a patient to destroy cancerous tumors; at the same time, the composite microspheres can generate heat upon application of a magnetic field to also destroy the tumors. The results showed that the composite microspheres were chemically durable when immersed in a simulated body fluid (SBF), with ∼ 0.25% weight loss and ∼ 3.2% yttrium dissolved into the SBF after 30 days at 37 °C. The composite microspheres also showed ferromagnetic properties as a result of the Fe 3 O 4 coating; when immersed in water at 20 °C (20 mg in 1 mL of water), the application of an alternating magnetic field produced a temperature increase from 20 °C to 38−46 °C depending on the thickness of the Fe 3 O 4 coating. The results indicate that these composite microspheres have promising potential in combined brachytherapy and hyperthermia treatment of cancerous tumors. - Highlights: ► Composite microspheres for brachytherapy and hyperthermia treatment of cancer. ► Fe 3 O 4 nanoparticles coated on the yttrium–aluminum–silicate glass microspheres. ► Microspheres are chemically stable in SBF. ► Microspheres can generate heat for hyperthermia under an alternating magnetic field. ► Microspheres can emit β-rays for brachytherapy after neutron activation.

  1. Association of rectal toxicity with thermal dose parameters in treatment of locally advanced prostate cancer with radiation and hyperthermia

    International Nuclear Information System (INIS)

    Hurwitz, Mark D.; Kaplan, Irving D.; Hansen, Jorgen L.; Prokopios-Davos, Savina; Topulos, George P.; Wishnow, Kenneth; Manola, Judith; Bornstein, Bruce A.; Hynynen, Kullervo

    2002-01-01

    Purpose: Although hyperthermia has been used for more than two decades in the treatment of pelvic tumors, little is known about the potential impact of heat on rectal toxicity when combined with other treatment modalities. Because rectal toxicity is a concern with radiation and may be exacerbated by hyperthermia, definition of the association of thermal dose parameters with rectal toxicity is important. In this report, we correlate rectal toxicity with thermal dose parameters for patients treated with hyperthermia and radiation for prostate cancer. Methods and Materials: Thirty patients with T2b-T3b disease (1992 American Joint Committee On Cancer criteria) enrolled in a Phase II study of external beam radiation ± androgen-suppressive therapy with two transrectal ultrasound hyperthermia treatments were assessed for rectal toxicity. Prostatic and anterior rectal wall temperatures were monitored for all treatments. Rectal wall temperatures were limited to 40 deg. C in 19 patients, 41 deg. C in 3 patients, and 42 deg. C in 8 patients. Logistic regression was used to estimate the log hazard of developing National Cancer Institute Common Toxicity Criteria Grade 2 toxicity based on temperature parameters. The following were calculated: hazard ratios, 95% confidence intervals, p values for statistical significance of each parameter, and proportion of variability explained for each parameter. Results: Gastrointestinal toxicity was limited to Grade 2. The rate of acute Grade 2 proctitis was greater for patients with an allowable rectal wall temperature of >40 deg. C. In this group, 7 of 11 patients experienced acute Grade 2 proctitis, as opposed to 3 of 19 patients in the group with rectal wall temperatures limited to 40 deg. C (p=0.004). Preliminary assessment of long-term toxicity revealed no differences in toxicity. Hazard ratios for acute Grade 2 proctitis for allowable rectal wall temperature, average rectal wall Tmax, and average prostate Tmax were 9.33 (p=0.01), 3

  2. Quantification of the clinical synergy between hyperthermia and radiation

    International Nuclear Information System (INIS)

    Crezee, Johannes; Kok, Petra; Bel, Arjan; Stalpers, Lukas; Franken, Klaas

    2014-01-01

    Hyperthermia (HT) therapy, raising tumor temperature to 41-45℃, enhances the effect of radiotherapy (RT) in tumor tissue. Combined HT-RT treatment is successfully applied for different tumors. The sensitizing effect of HT is maximal when given simultaneously with RT, but HT is more tumor selective when given before or after RT. Our purpose was to integrate existing preclinical and clinical data into an integrated RT-HT treatment planning system (R-HTP) to predict the biological effect of different sequences of RT and HT for clinically realistic temperatures and dose distributions. We developed a prototype R-HTP system and applied this for a retrospective analysis and comparison of RT+HT with RT alone for 15 prostate cancer patients. We used the linear quadratic (LQ) model with temperature dependent parameters alpha and beta obtained from the literature. The original RT plans were used which at 70 Gy on the PTV, in 35 2 Gy fractions. HT was simulated to be given with a phased array loco-regional HT system with realistic temperature distributions optimized to achieve maximal tumor temperature while maintaining normal tissue below 45℃. For the 15 patients an average median tumor temperature of 41.6℃ was achieved. This yielded an average effective radiotherapy dose of 86.1 Gy for the combined RT+HT treatment, compared to an average effective dose of 75.9 Gy when RT was given alone. The resulting increase in local tumor control probability (TCP) varies between 10% for low risk prostate cancer patients to 40% for high risk prostate cancer patients. This form of multi-modality planning is useful to predict the enhancement of RT by HT. (author)

  3. Modification of radiosensitivity of mammalian cells by means of hyperthermia and chemical agent. Coordinated programme on improvement of cancer therapy by the combination of treatment by conventional radiation and physical or chemical means

    International Nuclear Information System (INIS)

    Djordjevic, O.

    1984-11-01

    The effect of the treatment of the cultured mammalian cells with a relatively new anti-cancer drug teniposide (VM26), radiation (4 Gy), hyperthermia (42 deg. C and 45 deg. C) and caffeine, in various combinations, has been studied. The following conclusions can be drawn from the data obtained: The cultured mammalian cells respond to the anti-cancer drug VM26 treatment in a dose and time dependent manner. Significant potentiation of cell killing was demonstrated when they are exposed simultaneously to VM26 and hyperthermia. Post-treatment incubation of the cells in non-toxic concentration of caffeine (2 mM) has produced a marked potentiation of the lethal effect, indicating that caffeine interferes with the repair processes in these cells. Combination of VM26, hyperthermia and caffeine produced a maximum killing effect compared to VM26 treatment only. When the cells are exposed to initial (90 min. at 42 deg. C or 40 min. at 45 deg. C) and subsequent hyperthermia (60 min. at 42 deg. C or 60 min. at 45 deg. C) the thermotolerance will develop depending on the degree of initial and subsequent temperature. The combination of hyperthermia with irradiation results in a potentiation of the effect of treatment compared to the treatment with only irradiation or hyperthermia. Maximum killing of the cells will be obtained when irradiation is applied immediately after hyperthermia. The results obtained should be regarded as useful in case of clinical application of the tested agents

  4. The effect of hyperthermia in the preoperative combined treatment of radiation, hyperthermia and chemotherapy for rectal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, Fumio; Furuta, Kazuhiro; Saito, Yukio; Kataoka, Takashi; Kashiwagi, Hiroshi; Okada, Masaki; Kanazawa, Kyotaro; Sugahara, Tadashi; Shinohara, Naohiro (Jichi Medical School, Minamikawachi, Tochigi (Japan))

    1994-03-01

    To investigate the effectiveness of hyperthermia in the preoperative combined treatment of radiation, chemotherapy and hyperthermia for rectal carcinoma, two groups were compared. Group A consisted of 18 patients in whom hyperthermia, radiation and chemotherapy were performed. Group B consisted of 18 patients in whom only chemotherapy and radiation were performed. The total dose of radiation in both of the two groups was 40.5 Gy, and a radiation field covering the whole pelvis was used. Hyperthermia was performed using 8 MHz radiofrequency waves (Thermotron RF8, Yamamoto Vinyter, Japan), and tumors were heated at about 42 degrees C for 50 minutes. Hyperthermia was repeated five times during the preoperative treatment. Chemotherapy was performed by giving 5-fluorouracil suppositories to a total dose of 3400 mg. Mean tumor reduction rates on barium enema were 31.8% in group A and 18.2% in group B. The difference was statistically significant. The result of the histological assessment of tumor necrosis showed that there was a significantly higher degree of necrosis in group A than in group B. These results showed that the addition of hyperthermia enhanced tumor necrosis. It was concluded that the addition of hyperthermia would be an effective preoperative treatment of rectal carcinoma. (author).

  5. The effect of hyperthermia in the preoperative combined treatment of radiation, hyperthermia and chemotherapy for rectal carcinoma

    International Nuclear Information System (INIS)

    Konishi, Fumio; Furuta, Kazuhiro; Saito, Yukio; Kataoka, Takashi; Kashiwagi, Hiroshi; Okada, Masaki; Kanazawa, Kyotaro; Sugahara, Tadashi; Shinohara, Naohiro

    1994-01-01

    To investigate the effectiveness of hyperthermia in the preoperative combined treatment of radiation, chemotherapy and hyperthermia for rectal carcinoma, two groups were compared. Group A consisted of 18 patients in whom hyperthermia, radiation and chemotherapy were performed. Group B consisted of 18 patients in whom only chemotherapy and radiation were performed. The total dose of radiation in both of the two groups was 40.5 Gy, and a radiation field covering the whole pelvis was used. Hyperthermia was performed using 8 MHz radiofrequency waves (Thermotron RF8, Yamamoto Vinyter, Japan), and tumors were heated at about 42 degrees C for 50 minutes. Hyperthermia was repeated five times during the preoperative treatment. Chemotherapy was performed by giving 5-fluorouracil suppositories to a total dose of 3400 mg. Mean tumor reduction rates on barium enema were 31.8% in group A and 18.2% in group B. The difference was statistically significant. The result of the histological assessment of tumor necrosis showed that there was a significantly higher degree of necrosis in group A than in group B. These results showed that the addition of hyperthermia enhanced tumor necrosis. It was concluded that the addition of hyperthermia would be an effective preoperative treatment of rectal carcinoma. (author)

  6. Direct numerical simulations of the ignition of lean primary reference fuel/air mixtures with temperature inhomogeneities

    KAUST Repository

    Luong, Minhbau

    2013-10-01

    The effects of fuel composition, thermal stratification, and turbulence on the ignition of lean homogeneous primary reference fuel (PRF)/air mixtures under the conditions of constant volume and elevated pressure are investigated by direct numerical simulations (DNSs) with a new 116-species reduced kinetic mechanism. Two-dimensional DNSs were performed in a fixed volume with a two-dimensional isotropic velocity spectrum and temperature fluctuations superimposed on the initial scalar fields with different fuel compositions to elucidate the influence of variations in the initial temperature fluctuation and turbulence intensity on the ignition of three different lean PRF/air mixtures. In general, it was found that the mean heat release rate increases slowly and the overall combustion occurs fast with increasing thermal stratification regardless of the fuel composition under elevated pressure and temperature conditions. In addition, the effect of the fuel composition on the ignition characteristics of PRF/air mixtures was found to vanish with increasing thermal stratification. Chemical explosive mode (CEM), displacement speed, and Damköhler number analyses revealed that the high degree of thermal stratification induces deflagration rather than spontaneous ignition at the reaction fronts, rendering the mean heat release rate more distributed over time subsequent to thermal runaway occurring at the highest temperature regions in the domain. These analyses also revealed that the vanishing of the fuel effect under the high degree of thermal stratification is caused by the nearly identical propagation characteristics of deflagrations of different PRF/air mixtures. It was also found that high intensity and short-timescale turbulence can effectively homogenize mixtures such that the overall ignition is apt to occur by spontaneous ignition. These results suggest that large thermal stratification leads to smooth operation of homogeneous charge compression-ignition (HCCI

  7. The application of early post-operative combination therapy with interstitial hyperthermia in the treatment of malignant gliomas

    International Nuclear Information System (INIS)

    Stahl, H.; Wust, P.; Maier-Hauff, K.; Seebass, M.; Mischel, M.; Grammler, M.; Golde, G.; Loeffel, J.; Felix, R.

    1995-01-01

    A pilot study was performed to examine practicality, tolerability, effectiveness and scope for improvement in early postoperative hyperthermia treatment following catheter implantation as part of (partial) tumor resection. Each CT data set was transferred into a VAX 3100 workstation for retrospective analysis of the hyperthermia treatment. The implanted catheters were segmented and the distributions of power density and temperature were simulated. We sought to achieve the best possible temperature distributions by optimising the catheter arrangement in the planning calculations. The corresponding Ir-192-source brachytherapy treatments were simulated in a similar way using the implanted, as well as optimised catheter arrays. Intraoperative catheter implantation in 4 patients was problem-free. Postoperative complications were not observed, neither were infections. Interstitial microwave hyperthermia in combination with percutaneous irradiation or chemotherapy a few days after the operation was also tolerated well by all patients. Effective temperatures (of at least 42 C) were regularly achieved at measurement points, but the temperature distributions were unsatisfactory, with T 90 values (the temperature reached in at least 90% of the target volume) of under 38 C. Measured temperature/position curves showed qualitative correlation with the simulated calculations. The catheter positions determined by optimisation varied significantly from the positions clinically used. (orig./MG) [de

  8. Magnetic, structural and magnetocaloric properties of Ni-Si and Ni-Al thermoseeds for self-controlled hyperthermia.

    Science.gov (United States)

    Pandey, Sudip; Quetz, Abdiel; Aryal, Anil; Dubenko, Igor; Mazumdar, Dipanjan; Stadler, Shane; Ali, Naushad

    2017-11-01

    Self-controlled hyperthermia is a non-invasive technique used to kill or destroy cancer cells while preserving normal surrounding tissues. We have explored bulk magnetic Ni-Si and Ni-Al alloys as a potential thermoseeds. The structural, magnetic and magnetocaloric properties of the samples were investigated, including saturation magnetisation, Curie temperature (T C ), and magnetic and thermal hysteresis, using room temperature X-ray diffraction and magnetometry. The annealing time, temperature and the effects of homogenising the thermoseeds were studied to determine the functional hyperthermia applications. The bulk Ni-Si and Ni-Al binary alloys have Curie temperatures in the desired range, 316 K-319 K (43 °C-46 °C), which is suitable for magnetic hyperthermia applications. We have found that T C strictly follows a linear trend with doping concentration over a wide range of temperature. The magnetic ordering temperature and the magnetic properties can be controlled through substitution in these binary alloys.

  9. Experience with a small animal hyperthermia ultrasound system (SAHUS): report on 83 tumours

    International Nuclear Information System (INIS)

    Novak, P; Moros, E G; Parry, J J; Rogers, B E; Myerson, R J; Zeug, A; Locke, J E; Rossin, R; Straube, W L; Singh, A K

    2005-01-01

    An external local ultrasound (US) system was developed to induce controlled hyperthermia of subcutaneously implanted tumours in small animals (e.g., mice and rats). It was designed to be compatible with a small animal positron emission tomography scanner (microPET) to facilitate studies of hyperthermia-induced tumour re-oxygenation using a PET radiopharmaceutical, but it is applicable for any small animal study requiring controlled heating. The system consists of an acrylic applicator bed with up to four independent 5 MHz planar disc US transducers of 1 cm in diameter, a four-channel radiofrequency (RF) generator, a multiple thermocouple thermometry unit, and a personal computer with custom monitoring and controlling software. Although the system presented here was developed to target tumours of up to 1 cm in diameter, the applicator design allows for different piezoelectric transducers to be exchanged and operated within the 3.5-6.5 MHz band to target different tumour sizes. Temperature feedback control software was developed on the basis of a proportional-integral-derivative (PID) approach when the measured temperatures were within a selectable temperature band about the target temperature. Outside this band, an on/off control action was applied. Perfused tissue-mimicking phantom experiments were performed to determine optimum controller gain constants, which were later employed successfully in animal experiments. The performance of the SAHUS (small animal hyperthermia ultrasound system) was tested using several tumour types grown in thighs of female nude (nu/nu) mice. To date, the system has successfully treated 83 tumours to target temperatures in the range of 41-43 deg. C for periods of 65 min on average

  10. A novel temperature-gradient Na±β-alumina solid electrolyte based SOx gas sensor without gaseous reference electrode

    DEFF Research Database (Denmark)

    Rao, N.; Bleek, C.M. Van den; Schoonman, J.

    1992-01-01

    An electrochemical SOx ps sensor with a tubular Na+-beta"-alumina solid electrolyte has been fabricated and tested under non-isothermal conditions. The temperature difference between the reference and working electrode of the sensor cell is about 100-degrees-C, which causes a serious deviation...... of the experimental EMF response from the value as calculated using the Nernst equation for an isothermal system. The experimental results are Consistent with the theoretical prediction for a non-isothermal system. The response time is usually less then 10 min. SEM and EDX have been employed to investigate the sensor...... material before and after use, confirming the formation of a glassy phase of Na2SO4 by an electrochemical reaction at the interface of the platinum electrodes and Na+-beta"-alumina. According to this new theoretical derivation, the sensor design could be simplified by applying the same SO2 ps at the two...

  11. Recognizing and managing a malignant hyperthermia crisis: guidelines from the European Malignant Hyperthermia Group

    DEFF Research Database (Denmark)

    Glahn, K P E; Ellis, F R; Halsall, P J

    2010-01-01

    Survival from a malignant hyperthermia (MH) crisis is highly dependent on early recognition and prompt action. MH crises are very rare and an increasing use of total i.v. anaesthesia is likely to make it even rarer, leading to the potential risk of reduced awareness of MH. In addition, dantrolene....... The guidelines consist of two textboxes: Box 1 on recognizing MH and Box 2 on the treatment of an MH crisis....

  12. Magnetic Nanoparticles Coated with a Thermosensitive Polymer with Hyperthermia Properties

    Directory of Open Access Journals (Sweden)

    Felisa Reyes-Ortega

    2017-12-01

    Full Text Available Magnetic nanoparticles (MNPs have been widely used to increase the efficacy of chemotherapeutics, largely through passive accumulation provided by the enhanced permeability and retention effect. Their incorporation into biopolymer coatings enables the preparation of magnetic field-responsive, biocompatible nanoparticles that are well dispersed in aqueous media. Here we describe a synthetic route to prepare functionalized, stable magnetite nanoparticles (MNPs coated with a temperature-responsive polymer, by means of the hydrothermal method combined with an oil/water (o/w emulsion process. The effects of both pH and temperature on the electrophoretic mobility and surface charge of these MNPs are investigated. The magnetite/polymer composition of these systems is detected by Fourier Transform Infrared Spectroscopy (FTIR and quantified by thermogravimetric analysis. The therapeutic possibilities of the designed nanostructures as effective heating agents for magnetic hyperthermia are demonstrated, and specific absorption rates as high as 150 W/g, with 20 mT magnetic field and 205 kHz frequency, are obtained. This magnetic heating response could provide a promising nanoparticle system for combined diagnostics and cancer therapy.

  13. Whole body thermal model of man during hyperthermia

    International Nuclear Information System (INIS)

    Charny, C.K.; Hagmann, M.J.; Levin, R.L.

    1987-01-01

    A whole body thermal model of man has been developed to predict the changes in regional temperatures and blood flows during hyperthermia treatments with the miniannular phased array (MAPA) and annular phased array (APA) applicators. A model of the thermoregulatory response to regional heating based on the experimental and numerical studies of others has been incorporated into this study. Experimentally obtained energy deposition patterns within a human leg exposed to the MAPA were input into the model and the results were compared to those based upon a theoretical deposition pattern. Exposure of the abdomen to the APA was modeled with and without the aberrant energy deposition that has been described previously. Results of the model reveal that therapeutic heating (>42 0 C) of extremity soft tissue sarcomas is possible without significant systemic heating. Very high bone temperatures (>50 0 C) were obtained when the experimental absorption pattern was used. Calculations show that systemic heating due to APA exposure is reduced via evaporative spray cooling techniques coupled with high-velocity ambient air flow

  14. Hyperthermia generated by Foucault currents for oncological treatments with COMSOL; Hipertermia generada por corrientes Foucault para tratamientos oncologicos con COMSOL

    Energy Technology Data Exchange (ETDEWEB)

    Romero C, R. L.; Cordova F, T.; Basurto I, G. [Universidad de Guanajuato, Campus Leon, Departamento de Ingenieria Fisica, Loma del Bosque 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Guzman C, R. [Universidad de Guanajuato, Campus Irapuato-Salamanca, Division de Ingenierias, Carretera Salamanca-Valle de Santiago Km 3.5, Comunidad de Palo Blanco, 36885 Salamanca, Guanajuato (Mexico); Castro L, J., E-mail: rosariolrc@gmail.com [Universidad del Mar, Campus Puerto Angel, Carretera a Zipolite Km 1.5, Col. Puerto Angel, 70902 San Pedro Pochutla, Oaxaca (Mexico)

    2017-10-15

    The hyperthermia generated by variable magnetic fields is a promising power method for oncological therapy, because apoptosis is induced in tumor cells at temperatures between 42 and 45 degrees Celsius. It is known that an alternating magnetic field on the FeO{sub 4} magnetite particles produces heat through three paths: is generated by parasitic currents, lost in hysteresis cycles and losses by magnetization relaxation; taking advantage of the energy losses through the joule effect and the transformation into heat, a simulation is shown in COMSOL about the temporal distribution of temperature in transformed biological systems, to have an estimate of the properties and behavior of the temperature gradient when magnetic hyperthermia is generated in human transformed tissue. (Author)

  15. Current Status and Perspectives of Hyperthermia in Cancer Therapy

    Science.gov (United States)

    Hiraoka, Masahiro; Nagata, Yasushi; Mitsumori, Michihide; Sakamoto, Masashi; Masunaga, Shin-ichiro

    2004-08-01

    Clinical trials of hyperthermia in combination with radiation therapy or chemotherapy undertaken over the past decades in Japan have been reviewed. Originally developed heating devices were mostly used for these trials, which include RF (radiofrequency) capacitive heating devices, a microwave heating device with a lens applicator, an RF intracavitary heating device, an RF current interstitial heating device, and ferromagnetic implant heating device. Non-randomized trials for various cancers, demonstrated higher response rate in thermoradiotherapy than in radiotherapy alone. Randomized trials undertaken for esophageal cancers also demonstrated improved local response with the combined use of hyperthermia. Furthermore, the complications associated with treatment were not generally serious. These clinical results indicate the benefit of combined treatment of hyperthermia and radiotherapy for various malignancies. On the other hand, the presently available heating devices are not satisfactory from the clinical viewpoints. With the advancement of heating and thermometry technologies, hyperthermia will be more widely and safely used in the treatment of cancers.

  16. Cellular and tissue effects of hyperthermia and radiation

    International Nuclear Information System (INIS)

    Field, S.B.

    1989-01-01

    This paper presents the idea that hyperthermia is likely to be most effective in poorly perfused regions, which is where radiotherapy and chemotherapy are least effective. The author suggests that a therapeutic gain might, therefore, be obtained by combined treatments

  17. A newly developed Fe-doped calcium sulfide nanoparticles with magnetic property for cancer hyperthermia

    Science.gov (United States)

    Wu, Steven Yueh-Hsiu; Tseng, Ching-Li; Lin, Feng-Huei

    2010-05-01

    In this study, a magnetic iron-doped calcium sulfide (Fe-CaS) nanoparticle was newly developed and studied for the purpose of hyperthermia due to its promising magnetic property, adequate biodegradation rate, and relatively good biocompatibility. Fe-CaS nanoparticles were synthesized by a wet chemical co-precipitation process with heat treatment in a N2 atmosphere, and were subsequently cooled in N2 and exposed to air at a low temperature. The crystal structure of the Fe-CaS nanoparticles was similar to that of the CaS, which was identified by an X-ray diffractometer (XRD). The particle size was less than 40 nm based on a Debye-Scherrer equation and transmission electron microscope (TEM) examination. Magnetic properties obtained from the SQUID magnetometer demonstrated that the synthesized CaS was a diamagnetic property. Once the Fe ions were doped, the synthesized Fe-CaS converted into paramagnetism which showed no hysteresis loop. Having been heated above 600 °C in N2, the Fe-CaS showed a promising magnetic property to produce enough energy to increase the temperature for hyperthermia. 10 mg/ml of the Fe-CaS was able to generate heat to elevate the media temperature over 42.5 °C within 6 min. The area of the hysteresis loop increased with the increasing of the treated temperature, especially at 800 °C for 1 h. This is because more Fe ions replaced Ca ions in the lattice at the higher heat treatment temperature. The heat production was also increasing with the increasing of heat treatment temperature, which resulted in an adequate specific absorption ratio (SAR) value, which was found to be 45.47 W/g at 37 °C under an alternative magnetic field of f = 750 KHz , H = 10 Oe. The in vitro biocompatibility test of the synthesized Fe-CaS nanoparticles examined by the LDH assay showed no cytotoxicity to 3T3 fibroblast. The result of in vitro cell hyperthermia shows that under magnetic field the Fe-CaS nanoparticles were able to generate heat and kill the CT-26 cancer

  18. A newly developed Fe-doped calcium sulfide nanoparticles with magnetic property for cancer hyperthermia

    International Nuclear Information System (INIS)

    Wu, Steven Yueh-Hsiu; Tseng, Ching-Li; Lin, Feng-Huei

    2010-01-01

    In this study, a magnetic iron-doped calcium sulfide (Fe-CaS) nanoparticle was newly developed and studied for the purpose of hyperthermia due to its promising magnetic property, adequate biodegradation rate, and relatively good biocompatibility. Fe-CaS nanoparticles were synthesized by a wet chemical co-precipitation process with heat treatment in a N 2 atmosphere, and were subsequently cooled in N 2 and exposed to air at a low temperature. The crystal structure of the Fe-CaS nanoparticles was similar to that of the CaS, which was identified by an X-ray diffractometer (XRD). The particle size was less than 40 nm based on a Debye-Scherrer equation and transmission electron microscope (TEM) examination. Magnetic properties obtained from the SQUID magnetometer demonstrated that the synthesized CaS was a diamagnetic property. Once the Fe ions were doped, the synthesized Fe-CaS converted into paramagnetism which showed no hysteresis loop. Having been heated above 600 o C in N 2 , the Fe-CaS showed a promising magnetic property to produce enough energy to increase the temperature for hyperthermia. 10 mg/ml of the Fe-CaS was able to generate heat to elevate the media temperature over 42.5 o C within 6 min. The area of the hysteresis loop increased with the increasing of the treated temperature, especially at 800 o C for 1 h. This is because more Fe ions replaced Ca ions in the lattice at the higher heat treatment temperature. The heat production was also increasing with the increasing of heat treatment temperature, which resulted in an adequate specific absorption ratio (SAR) value, which was found to be 45.47 W/g at 37 o C under an alternative magnetic field of f = 750 KHz, H = 10 Oe. The in vitro biocompatibility test of the synthesized Fe-CaS nanoparticles examined by the LDH assay showed no cytotoxicity to 3T3 fibroblast. The result of in vitro cell hyperthermia shows that under magnetic field the Fe-CaS nanoparticles were able to generate heat and kill the CT-26

  19. A seven-year disease-free survivor of malignant pleural mesothelioma treated with hyperthermia and chemotherapy: a case report

    Directory of Open Access Journals (Sweden)

    Okonogi Noriyuki

    2012-12-01

    Full Text Available Abstract Introduction Malignant pleural mesothelioma was once a rare finding but its incidence is increasing worldwide, most likely because of widespread exposure to asbestos. Although complete surgical resection is considered the only curative treatment, the results of surgery have shown a median survival time of only one year. In inoperable cases, chemotherapy, radiotherapy, and a combination of both have been considered as palliative therapy. Therefore, outcomes for inoperable cases have been poor. Here, we report the case of a long-term survivor treated with hyperthermia and chemotherapy. Case presentation A 61-year-old Japanese man with a performance status of 1 due to chest pain was referred to our hospital. He had a history of asbestos exposure for approximately five years. A computed tomography scan showed diffuse extensive right pleural thickening with small nodular lesions, and video-assisted thoracoscopy revealed tumor invasion of the ipsilateral chest wall muscles. The histopathologic findings were consistent with a diagnosis of malignant pleural mesothelioma (sarcomatoid type. The tumor was diagnosed as being stage cT3N0M0. Our patient refused any invasive therapies including surgery and radiotherapy, and was therefore treated with hyperthermia and systemic chemotherapy with agents such as cisplatin and irinotecan. He underwent three hyperthermia sessions and a single course of chemotherapy without any severe complications. One month after treatment, a follow-up computed tomography scan showed no definitive abnormality in the thoracic space. Our patient has subsequently survived without any evident disease for more than seven years. Conclusions The combination of hyperthermia and chemotherapy may be a novel and safe therapeutic option for malignant pleural mesothelioma, and can be considered for patients ineligible for radical treatment. Further clinical studies of the combination of hyperthermia and chemotherapy are needed to

  20. Partial body hyperthermia: a potent radioprotector

    International Nuclear Information System (INIS)

    Baydoun, S.; Alya, GH.; Taleb, M.; Mohammad, A.

    1995-12-01

    With the aim to investigate the potential role of some radioprotectors, partial body hyperthermia (PBH) was tested as a protector against the lethality induced by γ irradiation. Two groups of Wistar rats [gr.(1): Females and gr.(2): Males] were treated with PBH by 'dipping' the lower parts of the animals in water-bath at 43 C for 1 hr. Animals were, then, irradiated with a lethal dose of γ radiation (9 Gy) 20 hrs post PBH. Our results show that: -PHB has a protecting role against the lethality induced by γ irradiation with a protection factor [Survival in rats treated with PBH and radiation / survival in rats treated with radiation] of 10 in gr.(1) and 7 in gr.(2) - The role of PBH was more enhanced in females As compared with males. (author). 19 refs., 4 figs., 1 tab

  1. Partial Body Hyperthermia: A Potent radioprotector

    International Nuclear Information System (INIS)

    Baydoun, S.A.; Mohammad, A.; Alya, Gh.; Taleb, M.

    1998-01-01

    With the aim to investigate the potential role of some radioprotectors, partial body hyperthermia (PBH) was tested as a protector against the lethality induced by gamma-irradiation. Two groups of Wistar rats [ gr. (1): females and gr. (2): males] were treated with PBH by dipping the lower parts of the animals in water-bath at 43 degree for 1 hr. Animals were, then, irradiated with a lethal dose of gamma-radiation (9 Gy) 20 hr s post PBH. Our results show that: PBH has a protecting role against the lethality induced by gamma-irradiation with a protection factor [survival in rats treated with PBH and radiation/ survival in rats treated with radiation] of 10 in gr.(1) and 7 in gr. (2). The role of PBH was more enhanced in females as compared with males

  2. Temperature Pill

    Science.gov (United States)

    1988-01-01

    Ingestible Thermal Monitoring System was developed at Johns Hopkins University as means of getting internal temperature readings for treatments of such emergency conditions as dangerously low (hypothermia) and dangerously high (hyperthermia) body temperatures. ITMS's accuracy is off no more than one hundredth of a degree and provides the only means of obtaining deep body temperature. System has additional applicability in fertility monitoring and some aspects of surgery, critical care obstetrics, metabolic disease treatment, gerontology (aging) and food processing research. Three-quarter inch silicone capsule contains telemetry system, micro battery, and a quartz crystal temperature sensor inserted vaginally, rectally, or swallowed.

  3. [System design of small intellectualized ultrasound hyperthermia instrument in the LabVIEW environment].

    Science.gov (United States)

    Jiang, Feng; Bai, Jingfeng; Chen, Yazhu

    2005-08-01

    Small-scale intellectualized medical instrument has attracted great attention in the field of biomedical engineering, and LabVIEW (Laboratory Virtual Instrument Engineering Workbench) provides a convenient environment for this application due to its inherent advantages. The principle and system structure of the hyperthermia instrument are presented. Type T thermocouples are employed as thermotransducers, whose amplifier consists of two stages, providing built-in ice point compensation and thus improving work stability over temperature. Control signals produced by specially designed circuit drive the programmable counter/timer 8254 chip to generate PWM (Pulse width modulation) wave, which is used as ultrasound radiation energy control signal. Subroutine design topics such as inner-tissue real time feedback temperature control algorithm, water temperature control in the ultrasound applicator are also described. In the cancer tissue temperature control subroutine, the authors exert new improvments to PID (Proportional Integral Differential) algorithm according to the specific demands of the system and achieve strict temperature control to the target tissue region. The system design and PID algorithm improvement have experimentally proved to be reliable and excellent, meeting the requirements of the hyperthermia system.

  4. Destruction of radiation-resistant cell populations by hyperthermia

    International Nuclear Information System (INIS)

    Roettinger, E.M.; Gerweck, L.E.

    1979-01-01

    Animal experiments with local hyperthermia have shown that the radiauion dose necessary for the local control of 50% of the tumours examined was essentially reduced by heating to 42,5 0 C. In-vitro experients indicated selective destruction of relatively radiation-resistent cell populations by the combination of hyperthermie and reduced hydrogen ion concentration. Experiments with glioblastoma cells confirmed these results qualitatively, but showed quantitatively considerably lower sensitivity towards hyperthermia. (orig.) 891 MG/orig. 892 RDG [de

  5. Characterizing the transition region of an A508 cl3 steel using small specimens by the reference temperature and the weak-link distances

    International Nuclear Information System (INIS)

    Miranda, C.A.J.

    2001-01-01

    An experimental program was developed to characterize the transition region of an A508 cl3 steel. Some fracture mechanic specimens were tested in the transition region using three geometries with thickness B c values, the reference temperature values, To, associated with each geometry and test temperature, and the measured r wl distances and the theoretical ones. (author)

  6. Long-term patterns of air temperatures, daily temperature range, precipitation, grass-reference evapotranspiration and aridity index in the USA Great Plains: Part I. Spatial trends

    Science.gov (United States)

    Kukal, M.; Irmak, S.

    2016-11-01

    Due to their substantial spatio-temporal behavior, long-term quantification and analyses of important hydrological variables are essential for practical applications in water resources planning, evaluating the water use of agricultural crop production and quantifying crop evapotranspiration patterns and irrigation management vs. hydrologic balance relationships. Observed data at over 800 sites across the Great Plains of USA, comprising of 9 states and 2,307,410 km2 of surface area, which is about 30% of the terrestrial area of the USA, were used to quantify and map large-scale and long-term (1968-2013) spatial trends of air temperatures, daily temperature range (DTR), precipitation, grass-reference evapotranspiration (ETo) and aridity index (AI) at monthly, growing season and annual time steps. Air temperatures had a strong north to south increasing trend, with annual average varying from -1 to 24 °C, and growing season average temperature varying from 8 to 30 °C. DTR gradually decreased from western to eastern parts of the region, with a regional annual and growing season averages of 14.25 °C and 14.79 °C, respectively. Precipitation had a gradual shift towards higher magnitudes from west to east, with the average annual and growing season (May-September) precipitation ranging from 163 to 1486 mm and from 98 to 746 mm, respectively. ETo had a southwest-northeast decreasing trend, with regional annual and growing season averages of 1297 mm and 823 mm, respectively. AI increased from west to east, indicating higher humidity (less arid) towards the east, with regional annual and growing season averages of 0.49 and 0.44, respectively. The spatial datasets and maps for these important climate variables can serve as valuable background for climate change and hydrologic studies in the Great Plains region. Through identification of priority areas from the developed maps, efforts of the concerned personnel and agencies and resources can be diverted towards development

  7. Reirradiation + hyperthermia for recurrent breast cancer en cuirasse

    Energy Technology Data Exchange (ETDEWEB)

    Oldenborg, Sabine; Rasch, Coen R.N.; Os, Rob van; Kusumanto, Yoka H.; Voerde Sive Voerding, Paul J. zum; Crezee, Hans; Tienhoven, Geertjan van [University of Amsterdam (AMC), Department of Radiation Oncology, Z1-215, Academic Medical Center, Amsterdam (Netherlands); Oei, Bing S.; Venselaar, Jack L. [Institute Verbeeten (BVI), Department of Radiation Oncology, Tilburg (Netherlands); Heymans, Martijn W. [VU University Medical Center, Department of Epidemiology and Biostatistics, Amsterdam (Netherlands)

    2018-03-15

    Patients with irresectable locoregional recurrent breast cancer en cuirasse (BCEC) do not have effective curative treatment options. Hyperthermia, the elevation of tumor temperature to 40-45 C, is a well-established radio- and chemotherapy sensitizer. A total of 196 patients were treated with reirradiation and hyperthermia (reRT+HT) at two Dutch institutes from 1982-2005. The palliative effect was evaluated in terms of clinical outcome and toxicity. All patients received previous irradiation to a median dose of 50 Gy. In all, 75% of patients received 1-6 treatment modalities for previous tumor recurrences. ReRT consisted of 8 x 4 Gy given twice a week or 12 x 3 Gy given four times a week. Superficial hyperthermia was added once or twice a week. Tumor area comprised ≥1/2 of the ipsilateral chest wall. Overall clinical response rate was 72% (complete response [CR] 30%, partial response [PR] 42%, stable disease [SD] 22%, progressive disease [PD] 6%). The local progression-free rate at 1 year was 24%. Median survival was 6.9 months. Forty-three percent of our patients with CR, PR, SD after treatment remained infield progression-free until death or last follow-up. Acute ≥grade 3 toxicity occurred in 33% of patients, while late ≥grade 3 toxicity was recorded in 14% of patients. Tumor ulceration prior to treatment had a negative impact on both clinical outcome and toxicity. ReRT+HT provides sustainable palliative tumor control, despite refractory, extensive tumor growth. Compared to currently available systemic treatment options, reRT+HT is more effective with less toxicity. (orig.) [German] Fuer Patienten mit inoperablen lokoregionalen Rueckfaellen von Brustkrebs in Form eines Cancer en cuirasse (BCEC) gibt es keine effektiven kurativen Behandlungsoptionen. Die Hyperthermie, bei der die Tumortemperatur auf 40-45 C erhoeht wird, ist eine etablierte Methode zur Radio- und Chemotherapiesensibilisierung. Insgesamt 161 Patientinnen wurden in zwei niederlaendischen

  8. Effect of short-term scrotal hyperthermia on spermatological parameters, testicular blood flow and gonadal tissue in dogs.

    Science.gov (United States)

    Henning, H; Masal, C; Herr, A; Wolf, K; Urhausen, C; Beineke, A; Beyerbach, M; Kramer, S; Günzel-Apel, A-R

    2014-02-01

    The objective was to assess the effect of a short-term scrotal hyperthermia in dogs on quantitative and qualitative ejaculate parameters, testicular blood flow and testicular and epididymal histology. After a control period, the scrotum of seven normospermic adult beagle dogs was insulated with a self-made suspensory for 48 h. Nine weeks later, two animals were castrated, while in five animals, scrotal hyperthermia was repeated. Dogs were castrated either 10 or 40 days thereafter. In each phase of scrotal insulation, average scrotal surface temperature increased by 3.0°C. Semen was collected twice weekly throughout the experiment. Total sperm count did not change after the first hyperthermia, but it slightly decreased after the second (p sperm morphology and velocity parameters (CASA) rather indicated subtle physiological variations in sperm quality than effects of a local heat stress. Chromatin stability of ejaculated spermatozoa as indicated by SCSA remained constant throughout the experiment. Perfusion characteristics of the gonads, that is, systolic peak velocity, pulsatility and resistance index at the marginal location of the testicular artery, did not change due to hyperthermia (p > 0.05). Histological examination of excised testes and epididymides for apoptotic (TUNEL and activated caspase-3) and proliferating cells (Ki-67 antigen) indicated only marginal effects of scrotal insulation on tissue morphology. In conclusion, a mild short-term scrotal hyperthermia in dogs does not cause substantial changes in sperm quantity and quality. In contrast to other species, canine testes and epididymides may have a higher competence to compensate such thermal stress. © 2013 Blackwell Verlag GmbH.

  9. Thermal sensation during mild hyperthermia is modulated by acute postural change in humans

    Science.gov (United States)

    Takeda, Ryosuke; Imai, Daiki; Suzuki, Akina; Ota, Akemi; Naghavi, Nooshin; Yamashina, Yoshihiro; Hirasawa, Yoshikazu; Yokoyama, Hisayo; Miyagawa, Toshiaki; Okazaki, Kazunobu

    2016-12-01

    Thermal sensation represents the primary stimulus for behavioral and autonomic thermoregulation. We assessed whether the sensation of skin and core temperatures for the driving force of behavioral thermoregulation was modified by postural change from the supine (Sup) to sitting (Sit) during mild hyperthermia. Seventeen healthy young men underwent measurements of noticeable increase and decrease (±0.1 °C/s) of skin temperature (thresholds of warm and cold sensation on the skin, 6.25 cm2 of area) at the forearm and chest and of the whole-body warm sensation in the Sup and Sit during normothermia (NT; esophageal temperature (Tes), ˜36.6 °C) and mild hyperthermia (HT; Tes, ˜37.2 °C; lower legs immersion in 42 °C of water). The threshold for cold sensation on the skin at chest was lower during HT than NT in the Sit ( P body posture or temperature. The whole-body warm sensation was higher during HT than NT in both postures and higher in the Sit than Sup during both NT and HT (all, P cold on the skin and more whole-body warmth.

  10. Comparison of the effects of radiation and hyperthermia on prenatal retardation of brain growth of guinea-pigs

    International Nuclear Information System (INIS)

    Wanner, R.A.; Edwards, M.J.

    1983-01-01

    On day 21 of pregnancy guinea-pigs were exposed to hyperthermia or #betta# radiation. The effects on prenatal growth and especially brain growth of offspring were compared. Doses of 0.04-0.99 Gy of radiation produced a dose-dependent and irreversible reduction of brainweight in the offspring, but had little effect on body weight. Treatment with hyperthermia resulting in maternal temperatures of 41.8-43.9 0 C after exposure in a heated incubator for an hour also produced a dose-related micrencephaly in the offspring. Comparison of the two agents showed that a dose increment of 0.525 Gy of radiation produced a deficit in brain weight equivalent to an elevation of 1 0 C in maternal temperature. Using this guinea-pig brain weight assay system a threshold was detected of between 0.05 and 0.10 Gy for retardation of brain growth. (author)

  11. Synthesis of Gold Nanoparticles by Electro-reduction Method and Their Application as an Electro-hyperthermia System

    International Nuclear Information System (INIS)

    Yoon, Young Il; Kim, Kwangsoo; Kwon, Yongsoo; Cho, Heesang; Yoon, Changjin; Yoon, Taejong; Lee, Hak Jong

    2014-01-01

    We report the successful preparation of gold nanoparticles (Au NPs) using a novel electroreduction process, which is simple, fast, and environmentally friendly (toxic chemicals such as strong reducing agents are not required). Our process allows for the mass production of Au NPs and adequate particle size control. The Au NPs prepared show high biocompatibility and are non-toxic to healthy human cells. By applying radiofrequency (RF) ablation, we monitored the electro-hyperthermia effect of the Au NPs at different RFs. The Au NPs exhibit a fast increase in temperature to 55 .deg. C within 5 min during the application of an RF of 13 MHz. This temperature rise is sufficient to promote apoptosis through thermal stress. Our work suggests that the selective Au NP-mediated electro-hyperthermia therapy for tumor cells under an RF of 13 MHz has great potential as a clinical treatment for specific tumor ablation

  12. Influence of hypo- and hyperthermia on death time estimation - A simulation study.

    Science.gov (United States)

    Muggenthaler, H; Hubig, M; Schenkl, S; Mall, G

    2017-09-01

    Numerous physiological and pathological mechanisms can cause elevated or lowered body core temperatures. Deviations from the physiological level of about 37°C can influence temperature based death time estimations. However, it has not been investigated by means of thermodynamics, to which extent hypo- and hyperthermia bias death time estimates. Using numerical simulation, the present study investigates the errors inherent in temperature based death time estimation in case of elevated or lowered body core temperatures before death. The most considerable errors with regard to the normothermic model occur in the first few hours post-mortem. With decreasing body core temperature and increasing post-mortem time the error diminishes and stagnates at a nearly constant level. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Clinical thermometry, using the 27 MHz multi-electrode current-source interstitial hyperthermia system in brain tumours

    International Nuclear Information System (INIS)

    Kaatee, Robert S.J.P.; Nowak, Peter C.J.M.; Zee, Jacoba van der; Bree, Jacob de; Kanis, Bart P.; Crezee, Hans; Levendag, Peter C.; Visser, Andries G.

    2001-01-01

    Background and purpose: In interstitial hyperthermia, temperature measurements are mainly performed inside heating applicators, and therefore, give the maximum temperatures of a rather heterogeneous temperature distribution. The problem of how to estimate lesion temperatures using the multi-electrode current-source interstitial hyperthermia (MECS-IHT) system in the brain was studied. Materials and methods: Temperatures were measured within the electrodes and in an extra catheter at the edge of a 4x4x4.5 cm 3 glioblastoma multiforme resection cavity. From the temperature decays during a power-off period, information was obtained about local maximum and minimum tissue temperatures. The significance of these data was examined through model calculations. Results: Maximum tissue temperatures could be estimated roughly by switching off all electrodes for about 5 s. Model calculations showed that the minimum tissue temperatures near a certain afterloading catheter correspond well with the temperature of the applicator inside, about 1 min after this applicator was switched off. Conclusions: Although the electrode temperatures read during heating are not suitable to assess the temperature distribution, it is feasible to heat the brain adequately using the MECS-IHT system with extra sensors outside the electrodes and/or application of decay methods

  14. Dragon project reference design assessment study for a 528 MW (E) thorium cycle high temperature gas cooled reactor

    International Nuclear Information System (INIS)

    Hosegood, S.B.

    1967-05-01

    The report presents an assessment of the feasibility, safety and cost of a large nuclear power station employing a high temperature gas-cooled reactor. A thermal output 1250 MW was chosen for the study, resulting in a net electrical output of 528.34 MW from a single reactor station, or 1056.7 MW from a twin reactor station. A reference design has been developed and is described. The reactor uses a U-235/Th-232/U-233 fuel cycle, on a feed and breed basis. It is believed that such a reactor could be built at an early date, requiring only a relatively modest development programme. Building costs are estimated to be Pound46.66/kW for a single unit station and Pound42.6/kW for a twin station, with power generation costs of 1.67p/kWh and 1.50p/kWh respectively. Optimisation studies have not been carried out and it should be possible to improve on the costs. The design has been made as flexible as possible to allow units of smaller or larger outputs to be designed with a minimum of change. (U.K.)

  15. Critical Role of Peripheral Vasoconstriction in Fatal Brain Hyperthermia Induced by MDMA (Ecstasy) under Conditions That Mimic Human Drug Use

    Science.gov (United States)

    Kim, Albert H.; Wakabayashi, Ken T.; Baumann, Michael H.; Shaham, Yavin

    2014-01-01

    MDMA (Ecstasy) is an illicit drug used by young adults at hot, crowed “rave” parties, yet the data on potential health hazards of its abuse remain controversial. Here, we examined the effect of MDMA on temperature homeostasis in male rats under standard laboratory conditions and under conditions that simulate drug use in humans. We chronically implanted thermocouple microsensors in the nucleus accumbens (a brain reward area), temporal muscle, and facial skin to measure temperature continuously from freely moving rats. While focusing on brain hyperthermia, temperature monitoring from the two peripheral locations allowed us to evaluate the physiological mechanisms (i.e., intracerebral heat production and heat loss via skin surfaces) that underlie MDMA-induced brain temperature responses. Our data confirm previous reports on high individual variability and relatively weak brain hyperthermic effects of MDMA under standard control conditions (quiet rest, 22−23°C), but demonstrate dramatic enhancements of drug-induced brain hyperthermia during social interaction (exposure to male conspecific) and in warm environments (29°C). Importantly, we identified peripheral vasoconstriction as a critical mechanism underlying the activity- and state-dependent potentiation of MDMA-induced brain hyperthermia. Through this mechanism, which prevents proper heat dissipation to the external environment, MDMA at a moderate nontoxic dose (9 mg/kg or ∼1/5 of LD50 in rats) can cause fatal hyperthermia under environmental conditions commonly encountered by humans. Our results demonstrate that doses of MDMA that are nontoxic under cool, quiet conditions can become highly dangerous under conditions that mimic recreational use of MDMA at rave parties or other hot, crowded venues. PMID:24899699

  16. Covalent DNA-protein crosslinking occurs after hyperthermia and radiation

    International Nuclear Information System (INIS)

    Cress, A.E.; Bowden, G.T.

    1983-01-01

    Covalent DNA-protein crosslinks occur in exponentially growing mouse leukemia cells (L1210) after exposure to ionizing radiation. The amount of DNA-protein crosslinks as measured by a filter binding assay is dose dependent upon X irradiation. Although hyperthermia and radiation in combination are synergistic with respect to cell lethality, the combination does not result in an increase of DNA-protein crosslinks when assayed immediately following treatments. Hyperthermia (43 degrees C/15 min) given prior to radiation does not alter the radiation dose dependency of the amount of initial crosslinking. In addition, the amount of DNA-protein crosslinking produced by heat plus radiation is independent of the length of heating the cells at 43 degrees C. The DNA-protein crosslinks produced by 50-Gy X ray alone are removed after 2 hr at 37 degrees C. However, if hyperthermia (43 degrees C/15 min) is given prior to 100-Gy X ray, the removal of DNA-protein crosslinks is delayed until 4.0 hr after radiation. Phospho-serine and phospho-threonine bonds are not produced with either radiation or the combination of hyperthermia plus radiation as judged by the resistance of the bonds to guanidine hydrochloride. However, hyperthermia plus radiation causes an increase in phosphate to nitrogen type bonding. These results show that radiation alone causes covalent DNA-protein crosslinks. Hyperthermia in combination with radiation does not increase the total amount of the crosslinks but delays the removal of the crosslinks and alters the distribution of the types of chemical bonding. These data suggest that the synergistic action on hyperthermia with radiation is more related to the rate of removal and the type of chemical bonding involved in the covalent DNA-protein crosslinks rather than the amount of DNA-protein crosslinks

  17. TU-B-210-02: MRg HIFU - Advanced Approaches for Ablation and Hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Moonen, C. [University Medical Center Utrecht (Netherlands)

    2015-06-15

    MR guided focused ultrasound (MRgFUS), or alternatively high-intensity focused ultrasound (MRgHIFU), is approved for thermal ablative treatment of uterine fibroids and pain palliation in bone metastases. Ablation of malignant tumors is under active investigation in sites such as breast, prostate, brain, liver, kidney, pancreas, and soft tissue. Hyperthermia therapy with MRgFUS is also feasible, and may be used in conjunction with radiotherapy and for local targeted drug delivery. MRI allows in situ target definition and provides continuous temperature monitoring and subsequent thermal dose mapping during HIFU. Although MRgHIFU can be very precise, treatment of mobile organs is challenging and advanced techniques are required because of artifacts in MR temperature mapping, the need for intercostal firing, and need for gated HIFU or tracking of the lesion in real time. The first invited talk, “MR guided Focused Ultrasound Treatment of Tumors in Bone and Soft Tissue”, will summarize the treatment protocol and review results from treatment of bone tumors. In addition, efforts to extend this technology to treat both benign and malignant soft tissue tumors of the extremities will be presented. The second invited talk, “MRI guided High Intensity Focused Ultrasound – Advanced Approaches for Ablation and Hyperthermia”, will provide an overview of techniques that are in or near clinical trials for thermal ablation and hyperthermia, with an emphasis of applications in abdominal organs and breast, including methods for MRTI and tracking targets in moving organs. Learning Objectives: Learn background on devices and techniques for MR guided HIFU for cancer therapy Understand issues and current status of clinical MRg HIFU Understand strategies for compensating for organ movement during MRgHIFU Understand strategies for strategies for delivering hyperthermia with MRgHIFU CM - research collaboration with Philips.

  18. Development of high temperature reference electrodes for in-pile application: Part I. Feasibility study of the external pressure balanced Ag/AgCl reference electrode (EPBRE) and the cathodically charged Palladium hydrogen electrode

    International Nuclear Information System (INIS)

    Bosch, R.W.; Van Nieuwenhove, R.

    1998-10-01

    The main problems connected with corrosion potential measurements at elevated temperatures and pressures are related to the stability and lifetime of the reference electrode and the correct estimation of the potential related to the Standard Hydrogen Scale (SHE). Under Pressurised Water Reactor (PWR) conditions of 300 degrees Celsius and 150 bar, the choice of materials is also a limiting factor due to the influence of radiation. Investigations on two reference electrodes that can be used under PWR conditions are reported: the cathodically charged palladium hydrogen electrode, and the external pressure balanced silver/silver chloride electrode. Preliminary investigations with the Pd-electrode were focused on the calculation of the required charging time and the influence of dissolved oxygen. High temperature applications are discussed on the basis of results reported in the literature. Investigations with the silver/silver chloride reference electrode mainly dealt with the salt bridge which is necessary to connect the reference electrode with the testing solution. It is shown that the thermal junction potential is independent of the length of the salt bridge. In addition, the high temperature contributes to an increase of the conductivity of the solution, which is beneficial for the salt bridge connection

  19. Induction heating studies of combustion synthesized MgFe2O4 nanoparticles for hyperthermia applications

    International Nuclear Information System (INIS)

    Khot, V.M.; Salunkhe, A.B.; Thorat, N.D.; Phadatare, M.R.; Pawar, S.H.

    2013-01-01

    The structural, magnetic and ac magnetically induced heating characteristics of combustion synthesized MgFe 2 O 4 nanoparticles have been investigated for application in magnetic particle hyperthermia. As prepared nanoparticles showed ferrimagnetic behavior at room temperature with magnetization of about 33.83 emu/g at ±15 kOe. The solid state MgFe 2 O 4 nanoparticles exhibited specific absorption rate (SAR) of about 297 W/g at physiological safe range of frequency and amplitude. The increase in SAR and heating temperature in ac magnetic field was thought to be due to enhancement in magnetic hysteresis loss caused by dipole–dipole interactions in combustion synthesized MgFe 2 O 4 nanoparticles. - Highlights: ► Highly crystalline pure MgFe 2 O 4 nanoparticles were synthesized by low temperature combustion. ► Effect of ac magnetic field and nanoparticles concentration on heating characteristics of MgFe 2 O 4 nanoparticles was studied. ► Combustion synthesized MgFe 2 O 4 nanoparticles show highest specific absorption rate of 297 Wg −1 . ► The reported high value of specific absorption rate is advantageous for its use in magnetic particle hyperthermia

  20. Intracranial dual-mode IVUS and hyperthermia using circular arrays: preliminary experiments.

    Science.gov (United States)

    Patel, Vivek; Light, Edward; Herickhoff, Carl; Grant, Gerald; Britz, Gavin; Wilson, Christy; Palmeri, Mark; Smith, Stephen

    2013-01-01

    In this study, we investigated the feasibility of using 3.5-Fr (3 Fr = 1 mm) circular phased-array intravascular ultrasound (IVUS) catheters for minimally invasive, image-guided hyperthermia treatment of tumors in the brain. Feasibility was demonstrated in two ways: (1) by inserting a 3.5-Fr IVUS catheter through skull burr holes, for 20 MHz brain imaging in the pig model, and (2) by testing a modified circular array for therapy potential with 18.5-MHz and 9-MHz continuous wave (CW) excitation. The imaging transducer's performance was superior to our previous 9-MHz mechanical IVUS prototype. The therapy catheter transducer was driven by CW electrical power at 18.5 MHz, achieving temperature changes reaching +8°C at a depth of 2 mm in a human glioblastoma grown on the flank of a mouse with minimal transducer resistive heating of +2°C. Further hyperthermia trials showed that 9-MHz CW excitation produced temperature changes of +4.5°C at a depth of 12 mm-a sufficient temperature rise for our long-term goal of targeted, controlled drug release via thermosensitive liposomes for therapeutic treatment of 1-cm-diameter glioblastomas.

  1. Ultra-low power high temperature and radiation hard complementary metal-oxide-semiconductor (CMOS) silicon-on-insulator (SOI) voltage reference.

    Science.gov (United States)

    Boufouss, El Hafed; Francis, Laurent A; Kilchytska, Valeriya; Gérard, Pierre; Simon, Pascal; Flandre, Denis

    2013-12-13

    This paper presents an ultra-low power CMOS voltage reference circuit which is robust under biomedical extreme conditions, such as high temperature and high total ionized dose (TID) radiation. To achieve such performances, the voltage reference is designed in a suitable 130 nm Silicon-on-Insulator (SOI) industrial technology and is optimized to work in the subthreshold regime of the transistors. The design simulations have been performed over the temperature range of -40-200 °C and for different process corners. Robustness to radiation was simulated using custom model parameters including TID effects, such as mobilities and threshold voltages degradation. The proposed circuit has been tested up to high total radiation dose, i.e., 1 Mrad (Si) performed at three different temperatures (room temperature, 100 °C and 200 °C). The maximum drift of the reference voltage V(REF) depends on the considered temperature and on radiation dose; however, it remains lower than 10% of the mean value of 1.5 V. The typical power dissipation at 2.5 V supply voltage is about 20 μW at room temperature and only 75 μW at a high temperature of 200 °C. To understand the effects caused by the combination of high total ionizing dose and temperature on such voltage reference, the threshold voltages of the used SOI MOSFETs were extracted under different conditions. The evolution of V(REF) and power consumption with temperature and radiation dose can then be explained in terms of the different balance between fixed oxide charge and interface states build-up. The total occupied area including pad-ring is less than 0.09 mm2.

  2. Improvement of drug delivery by hyperthermia treatment using magnetic cubic cobalt ferrite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Dey, Chaitali, E-mail: chaitalidey29@gmail.com [Centre for Research in Nanoscience & Nanotechnology, Block-JD-2, Sector-III, Salt Lake, Kolkata 700106 (India); Baishya, Kaushik [S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700106 (India); Ghosh, Arup [S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700106 (India); Department of Physics, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune 411008 (India); Goswami, Madhuri Mandal, E-mail: madhuri@bose.res.in [S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700106 (India); Ghosh, Ajay [Dept. of Applied Optics and Photonics, University of Calcutta, Block-JD-2, Sector-III, Salt Lake, Kolkata 700106 (India); Mandal, Kalyan [S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700106 (India)

    2017-04-01

    In this study, we report a novel synthesis method, characterization and application of a new class of ferromagnetic cubic cobalt ferrite magnetic nanoparticles (MNPs) for hyperthermia therapy and temperature triggered drug release. The MNPs are characterized by XRD, TEM, FESEM, AC magnetic hysteresis and VSM. These MNPs were coated with folic acid and loaded with an anticancer drug. The drug release studies were done at two different temperatures (37 °C and 44 °C) with progress of time. It was found that higher release of drug took place at elevated temperature (44 °C). We have developed a temperature sensitive drug delivery system which releases the heat sensitive drug selectively as the particles are heated up under AC magnetic field and controlled release is possible by changing the external AC magnetic field.

  3. Comparison of ion temperature and ion density measured during geomagnetically very quiet conditions on board of the geophysical rocket ''Vertical-6'' with the international reference ionosphere

    International Nuclear Information System (INIS)

    Bencze, P.; Kovacs, K.; Apathy, I.; Szemerey, I.; Afonin, V.; Bezrukih, V.; Shutte, N.

    1980-05-01

    Ion temperature and ion density, measured on October 25, 1977 during the flight of the geophyisical rocket ''Vertical-6'' by means of a group of five retarding potential analyzers looking into different directions of space, are compared with the International Reference Ionosphere 1978. The measurements were carried out in a geomagnetically quiet period to a height of 1500 km. The results show that both the ion temperature and the ion density are lower than the values predicted by the Reference Ionosphere, the difference is decreasing with increasing altitude. (author)

  4. Magnetic hyperthermia of laponite based ferrofluid

    Energy Technology Data Exchange (ETDEWEB)

    Diamantopoulos, G., E-mail: gior15@ims.demokritos.gr [Institute of Materials Science, National Centre for Scientific Research ‘Demokritos’, 153 10 Aghia Paraskevi, Athens (Greece); Basina, G.; Tzitzios, V.; Karakosta, E.; Fardis, M. [Institute of Materials Science, National Centre for Scientific Research ‘Demokritos’, 153 10 Aghia Paraskevi, Athens (Greece); Jaglicic, Z. [University of Ljubljana, Faculty of Civil Engineering and Geodesy and Institute of Mathematics, Physics and Mechanics, Jadranska 19, 1000 Ljubljana (Slovenia); Lazaridis, N. [Aristotle University of Thessaloniki, Chemistry Department, 54124 Thessaloniki (Greece); Papavassiliou, G. [Institute of Materials Science, National Centre for Scientific Research ‘Demokritos’, 153 10 Aghia Paraskevi, Athens (Greece)

    2013-06-15

    Magnetic Hyperthermia experiments have been performed on different concentrations of magnetic iron oxide nanoparticles immobilized on nano-clay disks. The specific absorption rate (SAR) was measured in AC field amplitudes H{sub 0} from 7 to 30 kA/m. At low field amplitudes, SAR followed the usual H{sub 0}{sup 2} law whereas for higher field amplitudes a linear dependence was found for the higher concentrations. Measurements at three different field amplitudes were also performed for a wide range of iron oxide concentrations in order to determine the effect of the Brownian relaxation time to SAR. A field dependent maximum was observed and for fields up to 20 kA/m the power dissipation losses were well explained according to theoretical predictions. - Highlights: ► Influence of the AC field to the specific absorption rates (SAR). ► Transition point from the expected square dependence to a linear law between SAR and AC field amplitude. ► A field dependent maximum of the SAR values versus iron oxide concentration is observed. ► Experimental validation of the existing theoretical work.

  5. The influence of hyperthermia and irradiation on some bioelectric parameters of the cells

    International Nuclear Information System (INIS)

    Solic, F.; Milotic, B.; Stipcic-Solic, N.

    1986-01-01

    The simultaneously influence of hyperthermia and low intensity gamma irradiation on the biopotential and the resistance of Nitella cells were investigated. The effect induced by irradiation and hyperthermia is manifested as membrane repolarization while hyperthermia alone induced depolarization. The resistance of cells is in positive correlation with membrane potential. (author)

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-15

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

  8. Optimal size for heating efficiency of superparamagnetic dextran-coated magnetite nanoparticles for application in magnetic fluid hyperthermia

    Science.gov (United States)

    Shaterabadi, Zhila; Nabiyouni, Gholamreza; Soleymani, Meysam

    2018-06-01

    Dextran-coated magnetite (Fe3O4) nanoparticles with average particle sizes of 4 and 19 nm were synthesized through in situ and semi-two-step co-precipitation methods, respectively. The experimental results confirm the formation of pure phase of magnetite as well as the presence of dextran layer on the surface of modified magnetite nanoparticles. The results also reveal that both samples have the superparamagnetic behavior. Furthermore, calorimetric measurements show that the dextran-coated Fe3O4 nanoparticles with an average size of 4 nm cannot produce any appreciable heat under a biologically safe alternating magnetic field used in hyperthermia therapy; whereas, the larger ones (average size of 19 nm) are able to increase the temperature of their surrounding medium up to above therapeutic range. In addition, measured specific absorption rate (SAR) values confirm that magnetite nanoparticles with an average size of 19 nm are very excellent candidates for application in magnetic hyperthermia therapy.

  9. Thermo-sensitively and magnetically ordered mesoporous carbon nanospheres for targeted controlled drug release and hyperthermia application.

    Science.gov (United States)

    Chen, Lin; Zhang, Huan; Zheng, Jing; Yu, Shiping; Du, Jinglei; Yang, Yongzhen; Liu, Xuguang

    2018-03-01

    A multifunctional nanoplatform based on thermo-sensitively and magnetically ordered mesoporous carbon nanospheres (TMOMCNs) is developed for effective targeted controlled release of doxorubicin hydrochloride (DOX) and hyperthermia in this work. The morphology, specific surface area, porosity, thermo-stability, thermo-sensitivity, as well as magnetism properties of TMOMCNs were verified by high resolution transmission electron microscopy, field emission scanning electron microscopy, thermo-gravimetric analysis, X-ray diffraction, Brunauer-Emmeltt-Teller surface area analysis, dynamic light scattering and vibrating sample magnetometry measurement. The results indicate that TMOMCNs have an average diameter of ~146nm with a lower critical solution temperature at around 39.5°C. They are superparamagnetic with a magnetization of 10.15emu/g at 20kOe. They generate heat when inductive magnetic field is applied to them and have a normalized specific absorption rate of 30.23W/g at 230kHz and 290Oe, showing good potential for hyperthermia. The DOX loading and release results illustrate that the loading capacity is 135.10mg/g and release performance could be regulated by changing pH and temperature. The good targeting, DOX loading and release and hyperthermia properties of TMOMCNs offer new probabilities for high effectiveness and low toxicity of cancer chemotherapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Iron oxide nanoparticle hyperthermia and chemotherapy cancer treatment

    Science.gov (United States)

    Petryk, A. A.; Giustini, A. J.; Ryan, P.; Strawbridge, R. R.; Hoopes, P. J.

    2009-02-01

    The benefit of combining hyperthermia and chemotherapy to treat cancer is well established. However, combined therapy has not yet achieved standard of care status. The reasons are numerous and varied, however the lack of significantly greater tumor cell sensitivity to heat (as compared to normal cells) and the inability to deliver heat to the tumor in a precise manner have been major factors. Iron oxide nanoparticle (IONP) hyperthermia, alone and combined with other modalities, offers a new direction in hyperthermia cancer therapy via improved tumor targeting and an improved therapeutic ratio. Our preliminary studies have demonstrated tumor cell cytotoxicity (in vitro and in vivo) with IONP heat and cisplatinum (CDDP) doses lower than those necessary when using conventional heating techniques or cisplatinum alone. Ongoing studies suggest such treatment could be further improved through the use of targeted nanoparticles.

  11. Microwave hyperthermia as an adjuvant to radiation therapy. Summary experience of 256 multifraction treatment cases

    International Nuclear Information System (INIS)

    Bicher, H.I.

    1985-01-01

    Analysis is presented of a series of 256 human tumors treated under multifraction protocol regimes with standard controlled hyperthermia parameters and increasing doses of radiation therapy. Air cooled microwave applicators intracavitary and interstitial antennae operating at 915 or 300 MHz were used in various sites. Temperatures were measured by micro-thermocouples. Minimum tumor temperatures of 42 0 C were maintained at 1 hour, twice weekly. Treatment included a radiation dose of 1600-1700 rads. Tumor response was 94% with 60% or more total response. Frequency and duration of total responses depended mainly on the radiation dose. Skin tumors, melanomas, chest wall recurrences responded better than head and neck or intrapelvic recurrences. Side effects observed were minor burns; proctitis or oesophagitis with intracavitary devices; ulcerations or fistulae due to rapid tumor regression; 4 cases of pleuritis treating chest wall. Overall toxicity was less than 5%. In conclusion: 1) Combination heat-low dose radiation offers good palliation. 2) Response depends on radiation dose. 3) Combination of full dose radiation therapy plus hyperthermia proves to be well tolerated

  12. A new mild hyperthermia device to treat vascular involvement in cancer surgery.

    Science.gov (United States)

    Ware, Matthew J; Nguyen, Lam P; Law, Justin J; Krzykawska-Serda, Martyna; Taylor, Kimberly M; Cao, Hop S Tran; Anderson, Andrew O; Pulikkathara, Merlyn; Newton, Jared M; Ho, Jason C; Hwang, Rosa; Rajapakshe, Kimal; Coarfa, Cristian; Huang, Shixia; Edwards, Dean; Curley, Steven A; Corr, Stuart J

    2017-09-12

    Surgical margin status in cancer surgery represents an important oncologic parameter affecting overall prognosis. The risk of disease recurrence is minimized and survival often prolonged if margin-negative resection can be accomplished during cancer surgery. Unfortunately, negative margins are not always surgically achievable due to tumor invasion into adjacent tissues or involvement of critical vasculature. Herein, we present a novel intra-operative device created to facilitate a uniform and mild heating profile to cause hyperthermic destruction of vessel-encasing tumors while safeguarding the encased vessel. We use pancreatic ductal adenocarcinoma as an in vitro and an in vivo cancer model for these studies as it is a representative model of a tumor that commonly involves major mesenteric vessels. In vitro data suggests that mild hyperthermia (41-46 °C for ten minutes) is an optimal thermal dose to induce high levels of cancer cell death, alter cancer cell's proteomic profiles and eliminate cancer stem cells while preserving non-malignant cells. In vivo and in silico data supports the well-known phenomena of a vascular heat sink effect that causes high temperature differentials through tissues undergoing hyperthermia, however temperatures can be predicted and used as a tool for the surgeon to adjust thermal doses delivered for various tumor margins.

  13. Parametric investigation of heating due to magnetic fluid hyperthermia in a tumor with blood perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Liangruksa, Monrudee [Department of Engineering Science and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States); Ganguly, Ranjan [Department of Power Engineering, Jadavpur University, Kolkata 700098 (India); Puri, Ishwar K., E-mail: ikpuri@vt.ed [Department of Engineering Science and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States)

    2011-03-15

    Magnetic fluid hyperthermia (MFH) is a cancer treatment that can selectively elevate the tumor temperature without significantly damaging the surrounding healthy tissue. Optimal MFH design requires a fundamental parametric investigation of the heating of soft materials by magnetic fluids. We model the problem of a spherical tumor and its surrounding healthy tissue that are heated by exciting a homogeneous dispersion of magnetic nanoparticles infused only into the tumor with an external AC magnetic field. The key dimensionless parameters influencing thermotherapy are the Peclet, Fourier, and Joule numbers. Analytical solutions for transient and steady hyperthermia provide correlations between these parameters and the portions of tumor and healthy tissue that are subjected to a threshold temperature beyond which they are damaged. Increasing the ratio of the Fourier and Joule numbers also increases the tumor temperature, but doing so can damage the healthy tissue. Higher magnetic heating is required for larger Peclet numbers due to the larger convection heat loss that occurs through blood perfusion. A comparison of the model predictions with previous experimental data for MFH applied to rabbit tumors shows good agreement. The optimal MFH conditions are identified based on two indices, the fraction I{sub T} of the tumor volume in which the local temperature is above a threshold temperature and the ratio I{sub N} of the damaged normal tissue volume to the tumor tissue volume that also lies above it. The spatial variation in the nanoparticle concentration is also considered. A Gaussian distribution provides efficacy while minimizing the possibility of generating a tumor hot spot. Varying the thermal properties of tumor and normal tissue alters I{sub T}and I{sub N} but the nature of the temperature distribution remains unchanged. - Research highlights: > Analytical model of magnetic fluid hyperthermia of tumor tissue perfused with magnetic nanoparticles that is surrounded

  14. Parametric investigation of heating due to magnetic fluid hyperthermia in a tumor with blood perfusion

    International Nuclear Information System (INIS)

    Liangruksa, Monrudee; Ganguly, Ranjan; Puri, Ishwar K.

    2011-01-01

    Magnetic fluid hyperthermia (MFH) is a cancer treatment that can selectively elevate the tumor temperature without significantly damaging the surrounding healthy tissue. Optimal MFH design requires a fundamental parametric investigation of the heating of soft materials by magnetic fluids. We model the problem of a spherical tumor and its surrounding healthy tissue that are heated by exciting a homogeneous dispersion of magnetic nanoparticles infused only into the tumor with an external AC magnetic field. The key dimensionless parameters influencing thermotherapy are the Peclet, Fourier, and Joule numbers. Analytical solutions for transient and steady hyperthermia provide correlations between these parameters and the portions of tumor and healthy tissue that are subjected to a threshold temperature beyond which they are damaged. Increasing the ratio of the Fourier and Joule numbers also increases the tumor temperature, but doing so can damage the healthy tissue. Higher magnetic heating is required for larger Peclet numbers due to the larger convection heat loss that occurs through blood perfusion. A comparison of the model predictions with previous experimental data for MFH applied to rabbit tumors shows good agreement. The optimal MFH conditions are identified based on two indices, the fraction I T of the tumor volume in which the local temperature is above a threshold temperature and the ratio I N of the damaged normal tissue volume to the tumor tissue volume that also lies above it. The spatial variation in the nanoparticle concentration is also considered. A Gaussian distribution provides efficacy while minimizing the possibility of generating a tumor hot spot. Varying the thermal properties of tumor and normal tissue alters I T and I N but the nature of the temperature distribution remains unchanged. - Research Highlights: →Analytical model of magnetic fluid hyperthermia of tumor tissue perfused with magnetic nanoparticles that is surrounded by healthy tissue

  15. Modelling of natural convection flows with large temperature differences: a benchmark problem for low Mach number solvers. Part. 1 reference solutions

    International Nuclear Information System (INIS)

    Le Quere, P.; Weisman, C.; Paillere, H.; Vierendeels, J.; Dick, E.; Becker, R.; Braack, M.; Locke, J.

    2005-01-01

    Heat transfer by natural convection and conduction in enclosures occurs in numerous practical situations including the cooling of nuclear reactors. For large temperature difference, the flow becomes compressible with a strong coupling between the continuity, the momentum and the energy equations through the equation of state, and its properties (viscosity, heat conductivity) also vary with the temperature, making the Boussinesq flow approximation inappropriate and inaccurate. There are very few reference solutions in the literature on non-Boussinesq natural convection flows. We propose here a test case problem which extends the well-known De Vahl Davis differentially heated square cavity problem to the case of large temperature differences for which the Boussinesq approximation is no longer valid. The paper is split in two parts: in this first part, we propose as yet unpublished reference solutions for cases characterized by a non-dimensional temperature difference of 0.6, Ra 10 6 (constant property and variable property cases) and Ra = 10 7 (variable property case). These reference solutions were produced after a first international workshop organized by Cea and LIMSI in January 2000, in which the above authors volunteered to produce accurate numerical solutions from which the present reference solutions could be established. (authors)

  16. Strategies to reduce hyperthermia in ambulatory multiple sclerosis patients.

    Science.gov (United States)

    Edlich, Richard F; Buschbacher, Ralph M; Cox, Mary Jude; Long, William B; Winters, Kathryne L; Becker, Daniel G

    2004-01-01

    Approximately 400,000 Americans have multiple sclerosis. Worldwide, multiple sclerosis affects 2.5 million individuals. Multiple sclerosis affects two to three times as many women as men. The adverse effects of hyperthermia in patients with multiple sclerosis have been known since 1890. While most patients with multiple sclerosis experience reversible worsening of their neurologic deficits, some patients experience irreversible neurologic deficits. In fact, heat-induced fatalities have been encountered in multiple sclerosis patients subjected to hyperthermia. Hyperthermia can be caused through sun exposure, exercise, and infection. During the last 50 years, numerous strategies have evolved to reduce hyperthermia in individuals with multiple sclerosis, such as photoprotective clothing, sunglasses, sunscreens, hydrotherapy, and prevention of urinary tract infections. Hydrotherapy has become an essential component of rehabilitation for multiple sclerosis patients in hospitals throughout the world. On the basis of this positive hospital experience, hydrotherapy has been expanded through the use of compact aquatic exercise pools at home along with personal cooling devices that promote local and systemic hypothermia in multiple sclerosis patients. The Multiple Sclerosis Association of America and NASA have played leadership roles in developing and recommending technology that will prevent hyperthermia in multiple sclerosis patients and should be consulted for new technological advances that will benefit the multiple sclerosis patient. In addition, products recommended for photoprotection by The Skin Cancer Foundation may also be helpful to the multiple sclerosis patient's defense against hyperthermia. Infections in the urinary tract, especially detrusor-external sphincter dyssynergia, are initially managed conservatively with intermittent self-catheterization and pharmacologic therapy. In those cases, refractory to conservative therapy, transurethral external

  17. Numerical modeling for an electric-field hyperthermia applicator

    Science.gov (United States)

    Wu, Te-Kao; Chou, C. K.; Chan, K. W.; Mcdougall, J.

    1993-01-01

    Hyperthermia, in conjunction with radiation and chemotherapy for treatment of cancers, is an area of current concern. Experiments have shown that hyperthermia can increase the potency of many chemotherapy drugs and the effectiveness of radiation for treating cancer. A combination of whole body or regional hyperthermia with chemotherapy or radiation should improve treatment results. Conventional methods for inducing whole body hyperthermia, such as exposing a patient in a radiant cabinet or under a hot water blanket, conduct heat very slowly from the skin to the body core. Thus a more efficient system, such as the three-plate electric-field hyperthermia applicator (EHA), is developed. This three-plate EHA has one top plate over and two lower plates beneath the patient. It is driven at 27.12 MHz with 500 Watts through a matching circuit. Using this applicator, a 50 kg pig was successfully heated to 42 C within 45 minutes. However, phantom and animal studies have indicated non-uniform heating near the side of the body. In addition, changes in the size and distance between the electrode plates can affect the heating (or electromagnetic field) pattern. Therefore, numerical models using the method of moments (MOM) or the finite difference time domain (FDTD) technique are developed to optimize the heating pattern of this EHA before it is used for human trials. The accuracy of the numerical modeling has been achieved by the good agreement between the MOM and FDTD results for the three-plate EHA without a biological body. The versatile FDTD technique is then applied to optimize the EHA design with a human body. Both the numerical and measured data in phantom blocks will be presented. The results of this study will be used to design an optimized system for whole body or regional hyperthermia.

  18. Covalent DNA-protein crosslinking occurs after hyperthermia and radiation

    International Nuclear Information System (INIS)

    Cress, A.E.; Bowden, G.T.

    1983-01-01

    Covalent DNA-protein crosslinks occur in exponentially growing mouse leukemia cells (L1210) after exposure to ionizing radiation. The amount of DNA-protein crosslinks as measured by a filter binding assay is dose dependent upon x irradiation. Although hyperthermia and radiation in combination are synergistic with respect to cell lethality, the combination does not result in an increase of DNA-protein crosslinks when assayed immediately following treatments. Hyperthermia (43 0 C/15 min) given prior to radiation dose not alter the radiation dose dependency of the amount of initial crosslinking. In addition, the amount of DNA-protein crosslinking produced by heat plus radiation is independent of the length of heating the cells at 43 0 C. The DNA-protein crosslinks produced y 50-Gy x ray alone are removed after 2 hr at 37 0 C. However, if hyperthermia (43 0 C/15 min) is given prior to 100-Gy x ray, the removal of DNA-protein crosslinks is delayed until 4.0 hr after radiation. Phospho-serine and phospho-threonine bonds are not produced with either radiation or the combination of hyperthermia plus radiation as judged by the resistance of the bonds to guanidine hydrochloride. However, hyperthermia plus radiation causes an increase in phosphate to nitrogen type bonding. These results show that radiation alone causes covalent DNA-protein crosslinks. Hyperthermia in combination with radiation does not increase the total amount of the crosslinks but delays the removal of the crosslinks and alters the distribution of the types of chemical bonding

  19. Improving immunological tumor microenvironment using electro-hyperthermia followed by dendritic cell immunotherapy.

    Science.gov (United States)

    Tsang, Yuk-Wah; Huang, Cheng-Chung; Yang, Kai-Lin; Chi, Mau-Shin; Chiang, Hsin-Chien; Wang, Yu-Shan; Andocs, Gabor; Szasz, Andras; Li, Wen-Tyng; Chi, Kwan-Hwa

    2015-10-15

    The treatment of intratumoral dentritic cells (DCs) commonly fails because it cannot evoke immunity in a poor tumor microenvironment (TME). Modulated electro-hyperthermia (mEHT, trade-name: oncothermia) represents a significant technological advancement in the hyperthermia field, allowing the autofocusing of electromagnetic power on a cell membrane to generate massive apoptosis. This approach turns local immunogenic cancer cell death (apoptosis) into a systemic anti-tumor immune response and may be implemented by treatment with intratumoral DCs. The CT26 murine colorectal cancer model was used in this investigation. The inhibition of growth of the tumor and the systemic anti-tumor immune response were measured. The tumor was heated to a core temperature of 42 °C for 30 min. The matured synergetic DCs were intratumorally injected 24 h following mEHT was applied. mEHT induced significant apoptosis and enhanced the release of heat shock protein70 (Hsp70) in CT26 tumors. Treatment with mEHT-DCs significantly inhibited CT26 tumor growth, relative to DCs alone or mEHT alone. The secondary tumor protection effect upon rechallenging was observed in mice that were treated with mEHT-DCs. Immunohistochemical staining of CD45 and F4/80 revealed that mEHT-DC treatment increased the number of leukocytes and macrophages. Most interestingly, mEHT also induced infiltrations of eosinophil, which has recently been reported to be an orchestrator of a specific T cell response. Cytotoxic T cell assay and ELISpot assay revealed a tumor-specific T cell activity. This study demonstrated that mEHT induces tumor cell apoptosis and enhances the release of Hsp70 from heated tumor cells, unlike conventional hyperthermia. mEHT can create a favorable tumor microenvironment for an immunological chain reaction that improves the success rate of intratumoral DC immunotherapy.

  20. Evaluation of segmentation algorithms for generation of patient models in radiofrequency hyperthermia

    International Nuclear Information System (INIS)

    Wust, P.; Gellermann, J.; Beier, J.; Tilly, W.; Troeger, J.; Felix, R.; Wegner, S.; Oswald, H.; Stalling, D.; Hege, H.C.; Deuflhard, P.

    1998-01-01

    Time-efficient and easy-to-use segmentation algorithms (contour generation) are a precondition for various applications in radiation oncology, especially for planning purposes in hyperthermia. We have developed the three following algorithms for contour generation and implemented them in an editor of the HyperPlan hyperthermia planning system. Firstly, a manual contour input with numerous correction and editing options. Secondly, a volume growing algorithm with adjustable threshold range and minimal region size. Thirdly, a watershed transformation in two and three dimensions. In addition, the region input function of the Helax commercial radiation therapy planning system was available for comparison. All four approaches were applied under routine conditions to two-dimensional computed tomographic slices of the superior thoracic aperture, mid-chest, upper abdomen, mid-abdomen, pelvis and thigh; they were also applied to a 3D CT sequence of 72 slices using the three-dimensional extension of the algorithms. Time to generate the contours and their quality with respect to a reference model were determined. Manual input for a complete patient model required approximately 5 to 6 h for 72 CT slices (4.5 min/slice). If slight irregularities at object boundaries are accepted, this time can be reduced to 3.5 min/slice using the volume growing algorithm. However, generating a tetrahedron mesh from such a contour sequence for hyperthermia planning (the basis for finite-element algorithms) requires a significant amount of postediting. With the watershed algorithm extended to three dimensions, processing time can be further reduced to 3 min/slice while achieving satisfactory contour quality. Therefore, this method is currently regarded as offering some potential for efficient automated model generation in hyperthermia. In summary, the 3D volume growing algorithm and watershed transformation are both suitable for segmentation of even low-contrast objects. However, they are not

  1. Temperature-based modeling of reference evapotranspiration using several artificial intelligence models: application of different modeling scenarios

    Science.gov (United States)

    Sanikhani, Hadi; Kisi, Ozgur; Maroufpoor, Eisa; Yaseen, Zaher Mundher

    2018-02-01

    The establishment of an accurate computational model for predicting reference evapotranspiration (ET0) process is highly essential for several agricultural and hydrological applications, especially for the rural water resource systems, water use allocations, utilization and demand assessments, and the management of irrigation systems. In this research, six artificial intelligence (AI) models were investigated for modeling ET0 using a small number of climatic data generated from the minimum and maximum temperatures of the air and extraterrestrial radiation. The investigated models were multilayer perceptron (MLP), generalized regression neural networks (GRNN), radial basis neural networks (RBNN), integrated adaptive neuro-fuzzy inference systems with grid partitioning and subtractive clustering (ANFIS-GP and ANFIS-SC), and gene expression programming (GEP). The implemented monthly time scale data set was collected at the Antalya and Isparta stations which are located in the Mediterranean Region of Turkey. The Hargreaves-Samani (HS) equation and its calibrated version (CHS) were used to perform a verification analysis of the established AI models. The accuracy of validation was focused on multiple quantitative metrics, including root mean squared error (RMSE), mean absolute error (MAE), correlation coefficient (R 2), coefficient of residual mass (CRM), and Nash-Sutcliffe efficiency coefficient (NS). The results of the conducted models were highly practical and reliable for the investigated case studies. At the Antalya station, the performance of the GEP and GRNN models was better than the other investigated models, while the performance of the RBNN and ANFIS-SC models was best compared to the other models at the Isparta station. Except for the MLP model, all the other investigated models presented a better performance accuracy compared to the HS and CHS empirical models when applied in a cross-station scenario. A cross-station scenario examination implies the

  2. Hyperthermia studies using inductive and ultrasound methods on E. coli bacteria and mouse glioma cells

    Energy Technology Data Exchange (ETDEWEB)

    Cabral–Prieto, A., E-mail: agustin.cabral@inin.gob.mx; López-Callejas, R., E-mail: regulo.lopez@inin.gob.mx; Rodríguez-Méndez, B. G., E-mail: benjamin.rodriguez@inin.gob.mx; Santos-Cuevas, C. L., E-mail: clara.cuevas@inin.gob.mx [Carretera México-Toluca s/n, La Marquesa, Instituto Nacional de Investigaciones Nucleares (Mexico); Celis-Almazán, J., E-mail: jony-jac-5@hotmail.com; Olea-Mejía, O., E-mail: oleaoscar@yahoo.com.mx [Universidad Autónoma del Estado de México, Centro Conjunto de Investigación en Química Sustentable (Mexico); Gómez-Morales, J. L. [Universidad Autónoma del Estado de México, Campus El Cerrillo, Facultad de Ciencias (Mexico); Peña-Eguiluz, R., E-mail: rosendo.eguiluz@inin.gob.mx; Valencia-Alvarado, R., E-mail: raul.valencia@inin.gob.mx; Mercado-Cabrera, A., E-mail: antonio.mercado@inin.gob.mx; Muñoz-Castro, A. E., E-mail: arturo.munoz@inin.gob.mx [Carretera México-Toluca s/n, La Marquesa, Instituto Nacional de Investigaciones Nucleares (Mexico); García-Santibañez, F., E-mail: fegasa2@yahoo.com.mx [Universidad Autónoma del Estado de México, Campus El Cerrillo, Facultad de Ciencias (Mexico)

    2017-11-15

    The survival of Escherichia coli bacteria and mouse glioma cells were studied under different temperatures using direct heating in water, ultrasound, and magnetic fluid hyperthermia. The survival of these microorganisms depended on whether the heating mode was continuous or discontinuous, surviving more in the former than in the discontinuous heating mode. Whereas Escherichia coli bacteria did not survive at temperatures ≥50{sup ∘}C, the mouse glioma cells did not survive at temperatures ≥48{sup ∘}C. The survival of both these microorganisms was independent of the presence or absence of the magnetic nanoparticles of magnetite, suggesting that these, having mean particle sizes of 9.5, 8.5 and 5, did not show any apparent cytotoxicity effect. Present results also showed that the inductive heating system which used a radiofrequency of 13.56 MHz, providing a maximum magnetic field strength of 160 A/m, the electric rather than magnetic heating predominated.

  3. Hyperthermia studies using inductive and ultrasound methods on E. coli bacteria and mouse glioma cells

    International Nuclear Information System (INIS)

    Cabral–Prieto, A.; López-Callejas, R.; Rodríguez-Méndez, B. G.; Santos-Cuevas, C. L.; Celis-Almazán, J.; Olea-Mejía, O.; Gómez-Morales, J. L.; Peña-Eguiluz, R.; Valencia-Alvarado, R.; Mercado-Cabrera, A.; Muñoz-Castro, A. E.; García-Santibañez, F.

    2017-01-01

    The survival of Escherichia coli bacteria and mouse glioma cells were studied under different temperatures using direct heating in water, ultrasound, and magnetic fluid hyperthermia. The survival of these microorganisms depended on whether the heating mode was continuous or discontinuous, surviving more in the former than in the discontinuous heating mode. Whereas Escherichia coli bacteria did not survive at temperatures ≥50"∘C, the mouse glioma cells did not survive at temperatures ≥48"∘C. The survival of both these microorganisms was independent of the presence or absence of the magnetic nanoparticles of magnetite, suggesting that these, having mean particle sizes of 9.5, 8.5 and 5, did not show any apparent cytotoxicity effect. Present results also showed that the inductive heating system which used a radiofrequency of 13.56 MHz, providing a maximum magnetic field strength of 160 A/m, the electric rather than magnetic heating predominated.

  4. The Dartmouth Center for Cancer Nanotechnology Excellence: magnetic hyperthermia.

    Science.gov (United States)

    Baker, Ian; Fiering, Steve N; Griswold, Karl E; Hoopes, P Jack; Kekalo, Katerina; Ndong, Christian; Paulsen, Keith; Petryk, Alicea A; Pogue, Brian; Shubitidze, Fridon; Weaver, John

    2015-01-01

    The Dartmouth Center for Cancer Nanotechnology Excellence - one of nine funded by the National Cancer Institute as part of the Alliance for Nanotechnology in Cancer - focuses on the use of magnetic nanoparticles for cancer diagnostics and hyperthermia therapy. It brings together a diverse team of engineers and biomedical researchers with expertise in nanomaterials, molecular targeting, advanced biomedical imaging and translational in vivo studies. The goal of successfully treating cancer is being approached by developing nanoparticles, conjugating them with Fabs, hyperthermia treatment, immunotherapy and sensing treatment response.

  5. Targeting therapy-resistant cancer stem cells by hyperthermia

    DEFF Research Database (Denmark)

    Oei, A L; Vriend, L E M; Krawczyk, P M

    2017-01-01

    Eradication of all malignant cells is the ultimate but challenging goal of anti-cancer treatment; most traditional clinically-available approaches fail because there are cells in a tumour that either escape therapy or become therapy-resistant. A subpopulation of cancer cells, the cancer stem cells...... are limited. Here, we argue that hyperthermia - a therapeutic approach based on local heating of a tumour - is potentially beneficial for targeting CSCs in solid tumours. First, hyperthermia has been described to target cells in hypoxic and nutrient-deprived tumour areas where CSCs reside and ionising...

  6. A 5 V-to-3.3 V CMOS Linear Regulator with Three-Output Temperature-Independent Reference Voltages

    Directory of Open Access Journals (Sweden)

    San-Fu Wang

    2016-01-01

    Full Text Available This paper presents a 5 V-to-3.3 V linear regulator circuit, which uses 3.3 V CMOS transistors to replace the 5 V CMOS transistors. Thus, the complexity of the manufacturing semiconductor process can be improved. The proposed linear regulator is implemented by cascode architecture, which requires three different reference voltages as the bias voltages of its circuit. Thus, the three-output temperature-independent reference voltage circuit is proposed, which provides three accurate reference voltages simultaneously. The three-output temperature-independent reference voltages also can be used in other circuits of the chip. By using the proposed temperature-independent reference voltages, the proposed linear regulator can provide an accurate output voltage, and it is suitable for low cost, small size, and highly integrated system-on-chip (SoC applications. Moreover, the proposed linear regulator uses the cascode technique, which improves both the gain performance and the isolation performance. Therefore, the proposed linear regulator has a good performance in reference voltage to output voltage isolation. The voltage variation of the linear regulator is less than 2.153% in the temperature range of −40°C–120°C, and the power supply rejection ratio (PSRR is less than −42.8 dB at 60 Hz. The regulator can support 0~200 mA output current. The core area is less than 0.16 mm2.

  7. A rare case of neuroleptic malignant syndrome presenting with serious hyperthermia treated with a non-invasive cooling device: a case report

    Directory of Open Access Journals (Sweden)

    Storm Christian

    2009-02-01

    Full Text Available Abstract Introduction A rare side effect of antipsychotic medication is neuroleptic malignant syndrome, mainly characterized by hyperthermia, altered mental state, haemodynamic dysregulation, elevated serum creatine kinase and rigor. There may be multi-organ dysfunction including renal and hepatic failure as well as serious rhabdomyolysis, acute respiratory distress syndrome and disseminated intravascular coagulation. The prevalence of neuroleptic malignant syndrome is between 0.02% and 2.44% for patients taking neuroleptics and it is not necessary to fulfil all cardinal features characterizing the syndrome to be diagnosed with neuroleptic malignant syndrome. Because of other different life-threatening diseases matching the various clinical findings, the correct diagnosis can sometimes be hard to make. A special problem of intensive care treatment is the management of severe hyperthermia. Lowering of body temperature, however, may be a major clinical problem because hyperthermia in neuroleptic malignant syndrome is typically unresponsive to antipyretic agents while manual cooling proves difficult due to peripheral vasoconstriction. Case presentation A 22-year-old Caucasian man was admitted unconscious with a body temperature of 42°C, elevated serum creatine phosphokinase, tachycardia and hypotonic blood pressure. In addition to intensive care standard therapy for coma and shock, a non-invasive cooling device (Arctic Sun 2000®, Medivance Inc., USA, originally designed to induce mild therapeutic hypothermia in patients after cardiopulmonary resuscitation, was used to lower body temperature. After successful treatment it became possible to obtain information from the patient about his recent ambulant treatment with Olanzapin (Zyprexa® for schizophrenia. Conclusion Numerous case reports have been published about patients who developed neuroleptic malignant syndrome due to Olanzapin (Zyprexa® medication. Frequently hyperthermia has been observed

  8. SU-F-J-05: The Effect of Air Pockets in the Urinary Bladder During Bladder Hyperthermia Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Schooneveldt, G.; Kok, H.P.; Bakker, A.; Geijsen, E.D.; Reijke, T.M. de; Crezee, J. [Academisch Medisch Centrum / Universiteit van Amsterdam, Amsterdam (Netherlands)

    2016-06-15

    Purpose: Hyperthermia combined with Mitomycin C is used for the treatment of non-muscle invasive bladder cancer (NMIBC), using a phased array system of microwave antennas for bladder heating. Often some air is present in the bladder, which effectively blocks the microwave radiation, potentially preventing proper treatment of that part of the bladder. Air can be a relevant fraction of the bladder content and large air pockets are expected to have a noticeable influence on achieved temperatures. Methods: We analysed 14 NMIBC patients treated at our institute with our AMC-4 hyperthermia device with four 70MHz antennas around the pelvis. A CT scan was made after treatment and a physician delineated the bladder on the CT scan. On the same scan, the amount of air present in the bladder was delineated. Using our in-house developed hyperthermia treatment planning system, we simulated the treatment using the clinically applied device settings. We did this once with the air pocket delineated on the CT scan, and once with the same volume filled with bladder tissue. Results: The patients had on average 4.2ml (range 0.8–10.1ml) air in the bladder. The bladder volume was delineated by the physician, that is including air pocket and bladder wall, was on average 253ml (range 93–452ml). The average volume in which changes exceeded 0.25°C was 22ml (range 0–108 ml), with the bladder being up to 2°C cooler when an air pocket was present. Except for extreme cases, there was no evident relation between the quantity of air and the difference in temperature. Conclusion: The effect of an air pocket in the bladder during bladder hyperthermia treatment varies strongly between patients. Generally, this leads to lower temperatures in the bladder, potentially affecting treatment quality, and suggesting that care need be taken to minimise the size of air pockets during hyperthermia treatments. The KWF Dutch Cancer Society financially supported this work, grant UVA 2012-5539.

  9. Preparation of Multifunctional Fe@Au Core-Shell Nanoparticles with Surface Grafting as a Potential Treatment for Magnetic Hyperthermia

    Directory of Open Access Journals (Sweden)

    Ren-Jei Chung

    2014-01-01

    Full Text Available Iron core gold shell nanoparticles grafted with Methotrexate (MTX and indocyanine green (ICG were synthesized for the first time in this study, and preliminarily evaluated for their potential in magnetic hyperthermia treatment. The core-shell Fe@Au nanoparticles were prepared via the microemulsion process and then grafted with MTX and ICG using hydrolyzed poly(styrene-alt-maleic acid (PSMA to obtain core-shell Fe@Au-PSMA-ICG/MTX nanoparticles. MTX is an anti-cancer therapeutic, and ICG is a fluorescent dye. XRD, TEM, FTIR and UV-Vis spectrometry were performed to characterize the nanoparticles. The data indicated that the average size of the nanoparticles was 6.4 ± 09 nm and that the Au coating protected the Fe core from oxidation. MTX and ICG were successfully grafted onto the surface of the nanoparticles. Under exposure to high frequency induction waves, the superparamagnetic nanoparticles elevated the temperature of a solution in a few minutes, which suggested the potential for an application in magnetic hyperthermia treatment. The in vitro studies verified that the nanoparticles were biocompatible; nonetheless, the Fe@Au-PSMA-ICG/MTX nanoparticles killed cancer cells (Hep-G2 via the magnetic hyperthermia mechanism and the release of MTX.

  10. Preparation of Multifunctional Fe@Au Core-Shell Nanoparticles with Surface Grafting as a Potential Treatment for Magnetic Hyperthermia.

    Science.gov (United States)

    Chung, Ren-Jei; Shih, Hui-Ting

    2014-01-24

    Iron core gold shell nanoparticles grafted with Methotrexate (MTX) and indocyanine green (ICG) were synthesized for the first time in this study, and preliminarily evaluated for their potential in magnetic hyperthermia treatment. The core-shell Fe@Au nanoparticles were prepared via the microemulsion process and then grafted with MTX and ICG using hydrolyzed poly(styrene-alt-maleic acid) (PSMA) to obtain core-shell Fe@Au-PSMA-ICG/MTX nanoparticles. MTX is an anti-cancer therapeutic, and ICG is a fluorescent dye. XRD, TEM, FTIR and UV-Vis spectrometry were performed to characterize the nanoparticles. The data indicated that the average size of the nanoparticles was 6.4 ± 09 nm and that the Au coating protected the Fe core from oxidation. MTX and ICG were successfully grafted onto the surface of the nanoparticles. Under exposure to high frequency induction waves, the superparamagnetic nanoparticles elevated the temperature of a solution in a few minutes, which suggested the potential for an application in magnetic hyperthermia treatment. The in vitro studies verified that the nanoparticles were biocompatible; nonetheless, the Fe@Au-PSMA-ICG/MTX nanoparticles killed cancer cells (Hep-G2) via the magnetic hyperthermia mechanism and the release of MTX.

  11. Effects of hyperthermia, radiotherapy and thermoradiotherapy on tumor microvasculature

    International Nuclear Information System (INIS)

    Fujiwara, Kouji

    1987-01-01

    The therapeutic effects of hyperthermia (immersion of tumor-bearing leg in a water bath at 46 deg C for 60 min), radiotherapy (500 rad or 1000 rad) and thermoradiotherapy on VX-2 tumors of the rabbits were studied morphologically. Especially, vascular morphological changes and vascular permeability to ferritin after treatment were investigated by electron microscopy. As assessed by decrease in tumor volume, local hyperthermia potentiated the destructive effect of radiotherapy. The light microscopic pictures invariably suggested prolonged necrotic tendency of tumor cells following thermoradiotherapy. Electron microscopically, 1 day and 3 days after thermoradiotherapy, small blood vessels in the tumors showed swelling and protrusion of endothelial cells in the lumen. Similar morphological changes were obtained only at 3 days after radiotherapy. When vascular permeability to ferritin was examined by electron microscopy, an increase in tumor vascular permeability was occured at 1 day after hyperthermia or thermoradiotherapy, while at 3 days after radiotherapy. These results suggest that the early reaction of tumor microvasculature may be a contributing factor to delayed cell death in tumors after hyperthermia or thermoradiotherapy. (author)

  12. Improving efficacy of hyperthermia in oncology by exploiting biological mechanisms

    DEFF Research Database (Denmark)

    van den Tempel, Nathalie; Horsman, Michael R; Kanaar, Roland

    2016-01-01

    It has long been established that hyperthermia increases the therapeutic benefit of radiation and chemotherapy in cancer treatment. During the last few years there have been substantial technical improvements in the sources used to apply and measure heat, which greatly increases enthusiasm for th...

  13. The effect of the malignant hyperthermia gene on carcass ...

    African Journals Online (AJOL)

    Malignant hyperthermia (MH) genotype, as expressed by the halo- thane genotype, was determined on a random sample of 100 pigs originating fiom the Western Cape. The pigs were slaughtered to investigate the effect of MH genotype on certain carcass character- istics and meat quality traits. Genotypes were determined ...

  14. Synthesis and magnetic hyperthermia studies on high susceptible Fe1-xMgxFe2O4 superparamagnetic nanospheres

    Science.gov (United States)

    Manohar, A.; Krishnamoorthi, C.

    2017-12-01

    Majority studies on magnetic hyperthermia properties were carried out by modifying the saturation mass magnetization (Ms) of the samples. Here efforts were made to enhance the specific heat generation rate (SHGR) of single domain superparamagnetic (SP) material by modifying its magnetic susceptibility. Well crystallined, inverse spinel structured and close to monosize Fe1-xMgxFe2O4 (x = 0, 0.1, 0.2, 0.3, 0.4, & 0.5) compounds with nanosphere geometry (diameter 10 nm) were synthesized by solvothermal reflux method at ≈ 300 °C . In the literature it is reported that magnesium ferrites synthesized at high temperatures yield mixed (normal & inverse) spinel structures. The inverse spinel structure was confirmed by X-ray powder diffraction (XRPD), lattice vibrations and magnetic characteristics of the compounds. The Ms of the compounds decrease with increase of substituent Mg2+ concentration. Under high excitation energy the inter-valance charge transfer whereas under low excitation energy the intra-valance charge transfer process were predominant. The as-synthesized nanospheres were encapsulated by hydrophobic oleic acid and were exchanged by hydrophilic poly(acrylic acid) by chemical exchange process. Estimated magnetic hyperthermia power or SHGR of the x = 0, 0.3 & 0.5 were 11, 11.4 & 22.4 W per gram of respective compounds, respectively, under 63.4 kA m-1 field amplitude and 126 kHz frequency. The SHGR enhances with Mg2+ concentration though its Ms reduces and is attributed to reduced spin-orbital coupling in the compounds with enhanced Mg2+ concentration. This may pave a new way to develop magnetic hyperthermia material by modifying magnetic susceptibility of the compounds against to the reported Ms modification approach. The obtained high SHGR of the biocompatible compounds could be used in magnetic hyperthermia applications in biomedical field.

  15. A support system in virtual reality for effective hyperthermia treatments. Heating properties of needle applicator for brain tumors

    International Nuclear Information System (INIS)

    Shindo, Yasuhiro; Iseki, Yuya; Nakane, Kazuya; Mimoto, Naoki; Kubo, Mitsunori; Kato, Kazuo; Takahashi, Hideaki; Uzuka, Takeo; Fujii, Yukihiko

    2011-01-01

    This paper describes the effectiveness of the developed simulator system for performing an effective hyperthermia treatment with a needle applicator in virtual reality (VR). The human brain is protected by the skull, which makes it difficult to non-invasively heat deep brain tumors with electromagnetic energy. Generally, needle applicators were used in clinical practice to heat brain tumors. However, some problems exist. One is that this heating method has a small heating area around the needle. In order to expand the heating area of a needle applicator, we developed a new type of needle applicator made from a shape memory alloy (SMA). The thermal properties of the SMA were checked experimentally using the developed heating system. As a result, the proposed needle applicator made of SMA is useful to create a wider heating area inside a tumor. Another problem is that medical doctors find it difficult to put a needle applicator into a target point inside of tumors. Therefore, a support system for performing an effective hyperthermia treatment is required in the clinic. In this paper, first, we constructed an anatomical 3-D model from magnetic resonance imaging (MRI) and X-ray computed tomography (CT) images by using 3-D computer aided design (CAD) software. Second, we presented the finite element method (FEM) model which is divided into non-linear elements on 3-D computer graphics (CG). Finally, we calculated temperature distributions using the 3-D FEM model with blood perfusion during hyperthermia treatments. From these results, it was found that the proposed VR system is effective for performing hyperthermia treatments. (author)

  16. One-dimensional phased array with mechanical motion for conformal ultrasound hyperthermia

    International Nuclear Information System (INIS)

    Ju, Kuen-Cheng; Chen, Yung-Yaw; Lin, Win-Li; Kuo, Te-Son

    2003-01-01

    This paper investigates the feasibility of conformal heating for external ultrasound hyperthermia by using a phased array transducer with mechanical motion. In this system, a one-dimensional phased array is arranged on a shaft and moves along the shaft, while dynamically focusing on the planning target volume (PTV) with numerous focal spots. To prevent overheating in the intervening tissue between the skin and the PTV, the shaft and the phased array are rotated together to enlarge the acoustical window. With the purpose of conformal heating, the power deposition of the PTV is constructed by combinations of the focal spots and an iterative gradient descent method is then used to determine an optimal set of power weightings for the focal spots. Different tumour shapes are evaluated and the simulation results demonstrate that the volume percentage of the PTV with temperatures higher than 43 deg. C is over 95%. The overheating volume outside the PTV is less than 25% of the PTV. This method provides good conformal heating for external ultrasound hyperthermia. The concept of combining electrical focusing and mechanical motion has the advantages of both enlarging the acoustic window and providing dynamic focusing ability, which is essential for successful conformal heating

  17. In Vivo Imaging of Local Gene Expression Induced by Magnetic Hyperthermia

    Directory of Open Access Journals (Sweden)

    Olivier Sandre

    2017-02-01

    Full Text Available The present work aims to demonstrate that colloidal dispersions of magnetic iron oxide nanoparticles stabilized with dextran macromolecules placed in an alternating magnetic field can not only produce heat, but also that these particles could be used in vivo for local and noninvasive deposition of a thermal dose sufficient to trigger thermo-induced gene expression. Iron oxide nanoparticles were first characterized in vitro on a bio-inspired setup, and then they were assayed in vivo using a transgenic mouse strain expressing the luciferase reporter gene under transcriptional control of a thermosensitive promoter. Iron oxide nanoparticles dispersions were applied topically on the mouse skin or injected subcutaneously with Matrigel™ to generate so-called pseudotumors. Temperature was monitored continuously with a feedback loop to control the power of the magnetic field generator and to avoid overheating. Thermo-induced luciferase expression was followed by bioluminescence imaging 6 h after heating. We showed that dextran-coated magnetic iron oxide nanoparticle dispersions were able to induce in vivo mild hyperthermia compatible with thermo-induced gene expression in surrounding tissues and without impairing cell viability. These data open new therapeutic perspectives for using mild magnetic hyperthermia as noninvasive modulation of tumor microenvironment by local thermo-induced gene expression or drug release.

  18. Specific absorption rate determination of magnetic nanoparticles through hyperthermia measurements in non-adiabatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Coïsson, M. [INRIM, strada delle Cacce 91, 10135 Torino (Italy); Barrera, G. [INRIM, strada delle Cacce 91, 10135 Torino (Italy); University of Torino, Chemistry Department, via P. Giuria 7, 10125 Torino (Italy); Celegato, F.; Martino, L.; Vinai, F. [INRIM, strada delle Cacce 91, 10135 Torino (Italy); Martino, P. [Politronica srl, via Livorno 60, 10144 Torino (Italy); Ferraro, G. [Center for Space Human Robotics, Istituto Italiano di Tecnologia - IIT, corso Trento 21, 10129 Torino (Italy); Tiberto, P. [INRIM, strada delle Cacce 91, 10135 Torino (Italy)

    2016-10-01

    An experimental setup for magnetic hyperthermia operating in non-adiabatic conditions is described. A thermodynamic model that takes into account the heat exchanged by the sample with the surrounding environment is developed. A suitable calibration procedure is proposed that allows the experimental validation of the model. Specific absorption rate can then be accurately determined just from the measurement of the sample temperature at the equilibrium steady state. The setup and the measurement procedure represent a simplification with respect to other systems requiring calorimeters or crucial corrections for heat flow. Two families of magnetic nanoparticles, one superparamagnetic and one characterised by larger sizes and static hysteresis, have been characterised as a function of field intensity, and specific absorption rate and intrinsic loss power have been obtained. - Highlights: • Development and thermodynamic modelling of a hyperthermia setup operating in non-adiabatic conditions. • Calibration of the experimental setup and validation of the model. • Accurate measurement of specific absorption rate and intrinsic loss power in non-adiabatic conditions.

  19. Magnetic hyperthermia properties of iron oxide nanoparticles: The effect of concentration

    Science.gov (United States)

    Ebrahimisadr, Saeid; Aslibeiki, Bagher; Asadi, Reza

    2018-06-01

    We investigated the effect of concentration on magnetic hyperthermia properties of Fe3O4 nanoparticles (NPs). The NPs were synthesized by co-precipitation method at 80 °C. Scanning electron microscope image showed that the mean diameter of NPs is about 18 nm. The XRD pattern indicated that the sample is pure Fe3O4 with spinel structure and the FT-IR spectroscopy confirmed formation of metal-oxygen bonds in the octahedral and tetrahedral spinel sub-lattice which further confirmed crystalline structure of the sample. The hyperthermia property of Fe3O4 NPs was investigated via an induction heater generating alternating magnetic field with frequency of 92 kHz. The temperature rise (ΔT) of suspension in the AC magnetic field was studied on different concentrations of NPs and the specific absorption rate (SAR) was obtained from Box-Lucas equation and linear fitting of ΔT-time curve. The results showed that the ΔT sharply increases with increasing the NPs concentration while the SAR remains almost constant.

  20. Postradiation DNA repair in mammalian cells under the combined effect of hyperthermia and 8-bromocaffeine and actinomycin D

    International Nuclear Information System (INIS)

    Rezvaya, S.P.; Khanson, K.P.

    1981-01-01

    A study was made of the influence of postirradiation hyperthermia combined with chemical inhibitirors of DNA repa on rejoining the singlestranded DNA breaks induced by X-irradiation (50 Gy) of LL, cells. Separation of single- and double-stranded DNA fragments on a column with hydroxyapatite has revealed that elevation of the postradiation incubation temperature up to 41 deg C does not influence the degree of repair of single-stranded breaks. No repair is detected at 43 deg C. 8-Bromocaffeine and actinomycin combined with the elevated temperature (41 deg C) remove the inhibitory effect of the preparations on the postradiation repair of DNA [ru

  1. Physical characteristics cannot be used to predict cooling time using cold-water immersion as a treatment for exertional hyperthermia.

    Science.gov (United States)

    Poirier, Martin P; Notley, Sean R; Flouris, Andreas D; Kenny, Glen P

    2018-03-12

    We examined if physical characteristics could be used to predict cooling time during cold water immersion (CWI, 2°C) following exertional hyperthermia (rectal temperature ≥39.5°C) in a physically heterogeneous group of men and women (n=62). Lean body mass was the only significant predictor of cooling time following CWI (R2=0.137; P<0.001); however that prediction did not provide the precision (mean residual square error: 3.18±2.28 min) required to act as a safe alternative to rectal temperature measurements.

  2. Effects of hyperthermia on cerebral blood flow and metabolism during prolonged exercise in humans

    DEFF Research Database (Denmark)

    Nybo, Lars; Møller, Kirsten; Volianitis, Stefanos

    2002-01-01

    The development of hyperthermia during prolonged exercise in humans is associated with various changes in the brain, but it is not known whether the cerebral metabolism or the global cerebral blood flow (gCBF) is affected. Eight endurance-trained subjects completed two exercise bouts on a cycle...... ergometer. The gCBF and cerebral metabolic rates of oxygen, glucose, and lactate were determined with the Kety-Schmidt technique after 15 min of exercise when core temperature was similar across trials, and at the end of exercise, either when subjects remained normothermic (core temperature = 37.9 degrees C...... with control at the end of exercise (43 +/- 4 vs. 51 +/- 4 ml. 100 g(-1). min(-1); P glucose, and the cerebral metabolic rate was therefore higher at the end...

  3. Mathematical modelling of the destruction degree of cancer under the influence of a RF hyperthermia

    Science.gov (United States)

    Paruch, Marek; Turchan, Łukasz

    2018-01-01

    The article presents the mathematical modeling of the phenomenon of artificial hyperthermia which is caused by the interaction of an electric field. The electric field is induced by the applicator positioned within the biological tissue with cancer. In addition, in order to estimate the degree of tumor destruction under the influence of high temperature an Arrhenius integral has been used. The distribution of electric potential in the domain considered is described by the Laplace system of equations, while the temperature field is described by the Pennes system of equations. These problems are coupled by source function being the additional component in the Pennes equation and resulting from the electric field action. The boundary element method is applied to solve the coupled problem connected with the heating of biological tissues.

  4. Magnetic fluid hyperthermia (MFH) as an alternative option in the treatment of recurrent malignant gliomas

    International Nuclear Information System (INIS)

    Maier-Hauff, K.; Jordan, A.; Nestler, D.; Scholz, R.; Feussner, A.; Gneveckow, U.; Wust, P.; Felix, R.

    2005-01-01

    Full text: The prognosis of glioblastoma (GB) remains poor despite the better neuro-imaging modalities and neurosurgical techniques. The survival of patients (PTS) depends on local tumor control, which is not guaranteed by the actual standard therapy. Magnetic fluid hyperthermia (MFH) in combination with external irradiation (RT) is a worldwide new method, which heats up selectively tumor tissue coupling a magnetic field to the applicated magnetic fluid (MF). In a phase I study with 16 PTS the applicability and tolerance of MFH combined with RT was evaluated. We present our preliminary results in 16 PTS. Depending on the tumor volume we implanted navigated 1-4 ml MF in the tumor area. The MF consists of iron oxide nanoparticles coated with a MG-specific shell dispersed in water. When the particles are exposed to an externally applied AC magnetic field, intratumoral steady-state temperatures of 43-50 o C or even higher for thermo ablation, were achieved during 60 minutes. The target temperature was measures continuously on-line by a 0.5 mm fibre optic invasive thermometry and controlled by the field strength of the AC magnetic field applicator. Four days after surgery irradiation was applied with 2 Gy / fraction 5 times a week plus 2 sessions of hyperthermia per week over 3 weeks. Because tumor power absorption was highly reproducible in each session, only the first six MFH treatments required thermometry. Further MFH applications were completely non-invasive. In 16 PTS 98 MFH therapies were done without side effects. In-vivo measured temperatures of 46 - 50 o C were highly reproducible in the target volume. In 16 cases MFH has been completed. During actual 15 months follow-up, 10 PTS showed no tumor progress where as in five PTS the tumor volume increased. Five PTS died of non tumor related complications and two PTS of tumor progress. The magnetic fluid hyperthermia in combination with radiation is a useful method for an intensified local treatment of recurrent

  5. Direct numerical simulations of the ignition of lean primary reference fuel/air mixtures with temperature inhomogeneities

    KAUST Repository

    Luong, Minhbau; Luo, Zhaoyu; Lu, Tianfeng; Chung, Suk-Ho; Yoo, Chun Sang

    2013-01-01

    simulations (DNSs) with a new 116-species reduced kinetic mechanism. Two-dimensional DNSs were performed in a fixed volume with a two-dimensional isotropic velocity spectrum and temperature fluctuations superimposed on the initial scalar fields with different

  6. Local hyperthermia of cervical N2/N3 lymph node metastases - a phase-I/II-study

    International Nuclear Information System (INIS)

    Stahl, H.; Wust, P.; Graf, R.; Loeffel, J.; Bier, J.; Riess, H.; Jahnke, V.; Felix, R.

    1997-01-01

    50 patients with primary advanced, recurrent or persistent N2/N3 lymph node metastases were treated with microwave hyperthermia in addition to their standard therapy (radiotherapy or radiochemotherapy). For the thermometry, closed-end catheters were implanted in the cervical lesions under CT monitoring. Temperature/time and temperature/position curves were analysed with regard to power density, effective perfusion, tissue depth, index temperatures T 90 , T 50 , T 20 , cum min T 60 ≥40.5 C, and equ min T 90 at 43 C. Radiation dose, total irradiation time and chemotherapy were also recorded as therapy parameters. Repeated CT scans for assessing response were taken for a subgroup of 32 patients following primary potentially curative radiotherapy (with and without chemotherapy) and local hyperthermia. All therapy parameters were subjected to a variance analysis with regard to response. At a tissue depth of 3 cm, relative and absolute power densities were on average of 50% less than at the surface. Therapeutic temperature increases of more than 4 C (i.e. more than 41 C) were not reached at tissue depths greater than 5 cm. The effective perfusion under local hyperthermia is significantly higher than under basal conditions. The mean T 90 was 39.9 C, and the mean T 20 value was 42.3 C. T 90 , cum min T 90 ≥40.5 C, equ min T 90 43 C, radiation dose and total irradiation time have a significant influence on response. The tumor volume correlates negatively with response, and this results in the thermal gradients correlating negatively with response and survival. The quality of the temperature distribution, represented by the value of cum min T 90 ≥40.5 C, showed a tendency to correlate positively with the survival in the subgroup of patients who underwent primary therapy. (orig./AJ) [de

  7. Children and adults exposed to electromagnetic fields at the ICNIRP reference levels: Theoretical assessment of the induced peak temperature increase

    NARCIS (Netherlands)

    J. Bakker (Jan); M.M. Paulides (Maarten); E. Neufeld; A. Christ (A.); N. Kuster (Niels); G.C. van Rhoon (Gerard)

    2011-01-01

    textabstractTo avoid potentially adverse health effects of electromagnetic fields (EMF), the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined EMF reference levels. Restrictions on induced whole-body-averaged specific absorption rate (SAR wb) are provided to keep the

  8. Induction of Localized Hyperthermia by Millisecond Laser Pulses in the Presence of Gold-Gold Sulphide Nanoparticles in a Phantom

    Directory of Open Access Journals (Sweden)

    Zahra Shahamat

    2015-05-01

    Full Text Available Introduction Application of near-infrared absorbing nanostructures can induce hyperthermia, in addition to providing more efficient  photothermal effects. Gold-gold sulfide (GGS is considered as one of these nanostructures. This study was performed on a tissue-equivalent optical-thermal phantom to determine the temperature profile in the presence and absence of GGS and millisecond pulses of a near-infrared laser. Moreover, the feasibility of hyperthermia induction was investigated in a simulated tumor. Materials and Methods A tumor with its surrounding tissues was simulated in a phantom made of Agarose and Intralipid. The tumor was irradiated by 30 laser pulses with durations of 30, 100, and 400 ms and fluences of 40 and 60 J/cm2. Temperature variations in the phantom with and without GGS were recorded, using fast-response sensors of a digital thermometer, placed at different distances from the central axis at three depths. The temperature rise was recorded by varying duration and fluence of the laser pulses. Results The rise in temperature was recorded by increasing laser fluence and number of pulses for three durations. The temperature profile was obtained at each depth. The presence of GGS resulted in a significant increase in temperature in all cases (P

  9. Nanotechnology in hyperthermia cancer therapy: From fundamental principles to advanced applications.

    Science.gov (United States)

    Beik, Jaber; Abed, Ziaeddin; Ghoreishi, Fatemeh S; Hosseini-Nami, Samira; Mehrzadi, Saeed; Shakeri-Zadeh, Ali; Kamrava, S Kamran

    2016-08-10

    In this work, we present an in-depth review of recent breakthroughs in nanotechnology for hyperthermia cancer therapy. Conventional hyperthermia methods do not thermally discriminate between the target and the surrounding normal tissues, and this non-selective tissue heating can lead to serious side effects. Nanotechnology is expected to have great potential to revolutionize current hyperthermia methods. To find an appropriate place in cancer treatment, all nanotechnology-based hyperthermia methods and their risks/benefits must be thoroughly understood. In this review paper, we extensively examine and compare four modern nanotechnology-based hyperthermia methods. For each method, the possible physical mechanisms of heat generation and enhancement due to the presence of nanoparticles are explained, and recent in vitro and in vivo studies are reviewed and discussed. Nano-Photo-Thermal Therapy (NPTT) and Nano-Magnetic Hyperthermia (NMH) are reviewed as the two first exciting approaches for targeted hyperthermia. The third novel hyperthermia method, Nano-Radio-Frequency Ablation (NaRFA) is discussed together with the thermal effects of novel nanoparticles in the presence of radiofrequency waves. Finally, Nano-Ultrasound Hyperthermia (NUH) is described as the fourth modern method for cancer hyperthermia. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. The Application of Miniaturized Three-Point-Bend Specimens for Determination of the Reference Temperature of A533 Cl.1 Steel

    Czech Academy of Sciences Publication Activity Database

    Stratil, Luděk; Šiška, Filip; Dlouhý, Ivo; Serrano, M.

    2017-01-01

    Roč. 139, č. 4 (2017), č. článku 041410. ISSN 0094-9930 R&D Projects: GA ČR GJ15-21292Y; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : fracture toughness * Master Curve * the reference temperature * JRQ steel * miniaturized specimens Subject RIV: JL - Materials Fatigue, Friction Mechanics OBOR OECD: Audio engineering, reliability analysis Impact factor: 0.729, year: 2016

  11. Effect of hyperthermia on experimental acute pancreatitis Efeito da hipertermia na pancreatite aguda experimental

    Directory of Open Access Journals (Sweden)

    José Luiz Jesus de Almeida

    2006-12-01

    Full Text Available BACKGROUD: Recent studies indicate that hyperthermia can change inflammatory mechanisms and protect experimental animals from deleterious effects of secretagogue-induced acute pancreatitis AIM: To evaluate the effects of hyperthermia post-treatment on cerulein-induced acute pancreatitis in rats METHODS: Twenty animals were divided in two groups: group I (n = 10, rats with cerulein-induced acute pancreatitis undergone hyperthermia, and group II (n = 10, animals with cerulein-induced acute pancreatitis that were kept normothermic. In all groups, amylase serum levels, histologic damage, vascular permeability and pancreatic water content were assessed. Acute pancreatitis was induced by administration of two cerulein injections (20 mcg/kg. A single dose of Evans' blue dye was administered along with the second dose of cerulein. All animals also received a subcutaneous injection of saline solution. After this process, animals undergone hyperthermia were heated in a cage with two 100 W lamps. Body temperature was increased to 39.5ºC and maintained at that level for 45 minutes. Normothermia rats were kept at room temperature in a second cage RESULTS: Control animals had typical edema, serum amylase activity and morphologic changes of this acute pancreatitis model. Hyperthermia post-treatment ameliorated the pancreatic edema, whereas the histologic damage and the serum amylase level remained unchanged CONCLUSIONS: The findings suggest a beneficial effect of the thermal stress on inflammatory edema in experimental acute pancreatitis.RACIONAL: Estudos recentes indicam que a hipertermia pode modificar mecanismos inflamatórios e proteger animais experimentais dos efeitos deletérios da pancreatite aguda induzida por secretagogos OBJETIVO: Avaliar a eficácia da hipertermia como tratamento da pancreatite aguda induzida por ceruleína em ratos MÉTODOS: Vinte animais foram divididos em dois grupos: grupo I (n = 10, ratos com pancreatite aguda induzida por

  12. Paleoclimatological context and reference level of the 2°C and 1.5°C Paris Agreement long-term temperature limits

    Science.gov (United States)

    Lüning, Sebastian; Vahrenholt, Fritz

    2017-12-01

    The Paris Agreement adopted in December 2015 during the COP21 conference stipulates that the increase in the global average temperature is to be kept well below 2°C above “pre-industrial levels” and that efforts are pursued to limit the temperature increase to 1.5°C above “pre-industrial levels”. In order to further increase public acceptance of these limits it is important to transparently place the target levels and their baselines in a paleoclimatic context of the past 150,000 years (Last Interglacial, LIG) and in particular of the last 10,000 years (Holocene; Present Interglacial, PIG). Intense paleoclimatological research of the past decade has firmed up that pre-industrial temperatures have been highly variable which needs to be reflected in the pre-industrial climate baseline definitions. The currently used reference level 1850-1900 represents the end of the Little Ice Age (LIA).The LIA represents the coldest phase of the last 10,000 years when mean temperatures deviated strongly negatively from the Holocene average and which therefore are hard to justify as a representative pre-industrial baseline. The temperature level reached during the interval 1940-1970 may serve as a better reference level as it appears to roughly correspond to the average pre-industrial temperature of the past two millennia. Placing the climate limits in an enlarged paleoclimatic context will help to demonstrate that the chosen climate targets are valid and represent dangerous extremes of the known natural range of Holocene temperature variability.

  13. Hyperthermia-induced micronucleus formation in a human keratinocyte cell line

    International Nuclear Information System (INIS)

    Hintzsche, Henning; Riese, Thorsten; Stopper, Helga

    2012-01-01

    Elevated temperature can cause biological effects in vitro and in vivo. Many studies on effects of hypo- and hyperthermia have been conducted, but only few studies systematically investigated the formation of genomic damage in the micronucleus test in human cells in vitro as a consequence of different temperatures. In the present study, HaCaT human keratinocytes were exposed to different temperatures from 37 °C to 42 °C for 24 h in a regular cell culture incubator. Micronucleus frequency as a marker of genomic damage was elevated in a temperature-dependent and statistically significant manner. Apoptosis occurred at temperatures of 39 °C or higher. Cell proliferation was unaffected up to 40 °C and decreased at 41 °C and 42 °C. Expression of the heat shock protein Hsp70 was elevated, particularly at temperatures of 40 °C and higher. These findings are in agreement with several in vivo studies and some in vitro studies looking at single, specific temperatures, but a systematically investigated temperature-dependent increase of genomic damage in human keratinocytes in vitro is demonstrated for the first time here.

  14. Implantation of the maxillary antrum for delivery of iridium brachytherapy and microwave induced hyperthermia

    International Nuclear Information System (INIS)

    Coughlin, C.T.; Wong, T.Z.; Geurkink, N.

    1985-01-01

    A 63 year-old male was referred tp Dartmouth in March 1984 for a locally advanced recurrent squamous cell carcinoma of the left maxillary antrum. This had been initially diagnosed in January 1983 by a Caldwell-Luc procedure and had failed partial resection, external radiation therapy, and multiagent chemotherapy. Our initial evaluation revealed disease replacing the left maxillary antrum, extending into the pterygomaxillary fossa, the lateral aspect of the superior alveloar ridge, and into the soft palate. He was taken to the operating room and under general anesthesia was implanted the 7 catheters through this tumor volume. Two days later a therapeutic (>42 0 C for 1 hour) hyperthermia treatment was administered followed by iridium placement. A second heating was performed upon removal of the iridium and was accomplished without major side effects. Thermometry data and follow-up are presented

  15. MDMA, Methylone, and MDPV: Drug-Induced Brain Hyperthermia and Its Modulation by Activity State and Environment.

    Science.gov (United States)

    Kiyatkin, Eugene A; Ren, Suelynn E

    2017-01-01

    Psychomotor stimulants are frequently used by humans to intensify the subjective experience of different types of social interactions. Since psychomotor stimulants enhance metabolism and increase body temperatures, their use under conditions of physiological activation and in warm humid environments could result in pathological hyperthermia, a life-threatening symptom of acute drug intoxication. Here, we will describe the brain hyperthermic effects of MDMA, MDPV, and methylone, three structurally related recreational drugs commonly used by young adults during raves and other forms of social gatherings. After a short introduction on brain temperature and basic mechanisms underlying its physiological fluctuations, we will consider how MDMA, MDPV, and methylone affect brain and body temperatures in awake freely moving rats. Here, we will discuss the role of drug-induced heat production in the brain due to metabolic brain activation and diminished heat dissipation due to peripheral vasoconstriction as two primary contributors to the hyperthermic effects of these drugs. Then, we will consider how the hyperthermic effects of these drugs are modulated under conditions that model human drug use (social interaction and warm ambient temperature). Since social interaction results in brain and body heat production, coupled with skin vasoconstriction that impairs heat loss to the external environment, these physiological changes interact with drug-induced changes in heat production and loss, resulting in distinct changes in the hyperthermic effects of each tested drug. Finally, we present our recent data, in which we compared the efficacy of different pharmacological strategies for reversing MDMA-induced hyperthermia in both the brain and body. Specifically, we demonstrate increased efficacy of the centrally acting atypical neuroleptic compound clozapine over the peripherally acting vasodilator drug, carvedilol. These data could be important for understanding the potential

  16. Effect of size and geometry of gold nanostructures in performance of laser-based hyperthermia: a multiscale- multiphysics modelling

    International Nuclear Information System (INIS)

    Samadinia, Hossein; Rafii-Tabar, Hashem; Sasanpour, Pezhman; Razaghi, Mohammad Reza; Nezhad, Mohammadreza Hormozi

    2016-01-01

    The importance of hyperthermia as a promising method in disruption and removal of cancerous cells is well understood. One of the effective options of concentration of heat within a specific tissue is using laser and exploiting absorption properties of metallic nanostructures. In this report, the geometrical effect of gold nanostructures in the performance of laser based hyperthermia has been analyzed. The analysis is based on the consideration of absorption properties of gold nanostructures, interaction of laser light with a specific tissue containing nanostructures and the effect of generated heat on elevation of temperature inside the tissue. The analysis is performed using Mie theory (for extraction of absorption/scattering properties of nanostructures), Monte Carlo (MC) (interaction of light inside the tissue) and solving the heat equation (considering the elevation of temperature inside the tissue). We have compared the effect of a laser beam on the maximum temperature inside the tissue and the results indicate that focusing the beam size of the laser to half width will culminate in a 50% elevation of maximum temperature in the tissue, while the average temperature raise inside the tissue will not be altered. (paper)

  17. Increased requirement for minute ventilation and negative arterial to end-tidal carbon dioxide gradient may indicate malignant hyperthermia

    Directory of Open Access Journals (Sweden)

    Ho-Tien Lin

    2014-04-01

    Full Text Available Characteristic signs of malignant hyperthermia (MH include unexplained tachycardia, increased end-tidal carbon dioxide (Etco2 concentration, metabolic and respiratory acidosis, and an increase in body temperature above 38.8°C. We present the case of a patient with highly probable MH. In addition to sinus tachycardia and metabolic and respiratory acidosis, this patient also had a negative arterial to Etco2 gradient and an increased requirement for minute ventilation to maintain a normal Etco2 concentration, with signs of increased CO2 production. Despite these signs of MH, the patient's rectal temperature monitoring equipment did not show an increase in temperature, although the temperature measured in the mouth was increased. This case illustrates the unreliability of measuring rectal temperature as a means of reflecting body temperature during MH and the usefulness of increased CO2 production signs in helping to diagnose MH.

  18. Simulating air temperature in an urban street canyon in all weather conditions using measured data at a reference meteorological station

    Science.gov (United States)

    Erell, E.; Williamson, T.

    2006-10-01

    A model is proposed that adapts data from a standard meteorological station to provide realistic site-specific air temperature in a city street exposed to the same meso-scale environment. In addition to a rudimentary description of the two sites, the canyon air temperature (CAT) model requires only inputs measured at standard weather stations; yet it is capable of accurately predicting the evolution of air temperature in all weather conditions for extended periods. It simulates the effect of urban geometry on radiant exchange; the effect of moisture availability on latent heat flux; energy stored in the ground and in building surfaces; air flow in the street based on wind above roof height; and the sensible heat flux from individual surfaces and from the street canyon as a whole. The CAT model has been tested on field data measured in a monitoring program carried out in Adelaide, Australia, in 2000-2001. After calibrating the model, predicted air temperature correlated well with measured data in all weather conditions over extended periods. The experimental validation provides additional evidence in support of a number of parameterisation schemes incorporated in the model to account for sensible heat and storage flux.

  19. Radiosensitization of hypoxic tumor cells by simultaneous administration of hyperthermia and nitroimidazoles

    International Nuclear Information System (INIS)

    Hofer, K.G.; Hofer, M.G.; Ieracitano, J.; McLaughlin, W.H.

    1977-01-01

    The radiation response of oxygenated and hypoxic L1210 leukemia cells subjected to in vivo treatments with hyperthermia and/or chemical radiosensitizers was evaluated with the [ 125 I]iododeoxyuridine prelabeling assay. X irradiation of L1210 cells at body temperatures of 41 0 C or higher resulted in strongly enhanced tumor cell death. The magnitude of this thermal effect increased with increasing temperatures. Hypoxic L1210 cells were particularly sensitive to heat induced enhancement of radiation damage, i.e., the sensitizing effects were more pronounced and occurred at lower temperatures. Chemical radiosensitizers (metronidazole, Ro 7-0582) selectively sensitized hypoxic L1210 populations; fully oxygenated cells were not affected. Considerable radiosensitization was achieved at nontoxic dose levels of the two sensitizers. Experiments designed to determine the degree of radiosensititization as a function of drug dose showed that Ro 7-0582 was consistently more effective than metronidazole in sensitizing hypoxic tumor populations. At the highest drug dose used (3 mg/g body wt) the DMF was 2.2 for metronidazole and 2.8 for Ro 7-0582. Combined administration of hyperthermia and Ro 7-0582 (or metronidazole) produced synergistic potentiation of radiation damage in hypoxic L1210 populations (DMF of 4.2). Under optimal conditions, hypoxic L1210 cells subjected simultaneously to both modes of radiosensitization became more radiosensitive than untreated, fully oxygenated L1210 cells. Experiments on two other tumor lines (BP-8 murine sarcoma and Ehrlich ascites cells) indicate that such synergistic radiosensitization effects are not unique to L1210 cells

  20. Optimizing Cold Water Immersion for Exercise-Induced Hyperthermia: A Meta-analysis.

    Science.gov (United States)

    Zhang, Yang; Davis, Jon-Kyle; Casa, Douglas J; Bishop, Phillip A

    2015-11-01

    Cold water immersion (CWI) provides rapid cooling in events of exertional heat stroke. Optimal procedures for CWI in the field are not well established. This meta-analysis aimed to provide structured analysis of the effectiveness of CWI on the cooling rate in healthy adults subjected to exercise-induced hyperthermia. An electronic search (December 2014) was conducted using the PubMed and Web of Science. The mean difference of the cooling rate between CWI and passive recovery was calculated. Pooled analyses were based on a random-effects model. Sources of heterogeneity were identified through a mixed-effects model Q statistic. Inferential statistics aggregated the CWI cooling rate for extrapolation. Nineteen studies qualified for inclusion. Results demonstrate CWI elicited a significant effect: mean difference, 0.03°C·min(-1); 95% confidence interval, 0.03-0.04°C·min(-1). A conservative, observed estimate of the CWI cooling rate was 0.08°C·min(-1) across various conditions. CWI cooled individuals twice as fast as passive recovery. Subgroup analyses revealed that cooling was more effective (Q test P immersion water temperature ≤10°C, ambient temperature ≥20°C, immersion duration ≤10 min, and using torso plus limbs immersion. There is insufficient evidence of effect using forearms/hands CWI for rapid cooling: mean difference, 0.01°C·min(-1); 95% confidence interval, -0.01°C·min(-1) to 0.04°C·min(-1). A combined data summary, pertaining to 607 subjects from 29 relevant studies, was presented for referencing the weighted cooling rate and recovery time, aiming for practitioners to better plan emergency procedures. An optimal procedure for yielding high cooling rates is proposed. Using prompt vigorous CWI should be encouraged for treating exercise-induced hyperthermia whenever possible, using cold water temperature (approximately 10°C) and maximizing body surface contact (whole-body immersion).

  1. The relationship between heating energy use, indoor temperature and heating energy demand under reference conditions in residential buildings

    Science.gov (United States)

    Magalhaes, Sara Moreira Coelho de

    The work described in this PhD Thesis focuses on the post-processing of optical fibers and their enhancement as sensing element. Since the majority of sensors presented are based in Fabry-Perot interferometers, an historical overview of this category of optical fiber sensors is firstly presented. This review considers the works published since the early years, in the beginning of the 1980s, until the middle of 2015. The incorporation of microcavities at the tip of a single mode fiber was extensively studied, particularly for the measurement of nitrogen and methane gas pressure. These cavities were fabricated using hollow core silica tubes and a hollow core photonic crystal fiber. Following a different approach, the microcavities were incorporated between two sections of single mode fiber. In this case, the low sensitivity to temperature makes these microcavities highly desirable for the measurement of strain at high temperatures. Competences in post-processing techniques such as the chemical etching and the writing of periodical structures in the fiber core by means of an excimer or a femtosecond laser were also acquired in the course of the PhD programme. One of the works consisted in the design and manufacturing of a double clad optical fiber. The refractive index of the inner cladding was higher than the one of the outer cladding and the core. Thus, light was guided in the inner cladding instead of propagating in the core. This situation was overcome by applying chemical etching, thus removing the inner cladding. The core, surrounded by air, was then able to guide light. Two different applications were found for this fiber, as a temperature sensor and as an optical refractometer. In the last, the optical phase changes with the liquid refractive index. Two different types of fiber Bragg gratings were characterized in strain and temperature. Sensing structures obtained through the phase mask technique at the tip of an optical fiber were subjected to chemical

  2. Reference core design Mark-III of the experimental multi-purpose, high-temperature, gas-cooled reactor

    International Nuclear Information System (INIS)

    Shindo, Ryuiti; Watanabe, Takashi; Ishiguro, Okikazu; Kuroki, Syuzi

    1977-10-01

    The reactivity control system is one of the important items in reactor design, but it is much restricted by structural design of fuel element and pressure vessel in the experimental multi-purpose, high-temperature reactor. Preceding the first conceptual design of the reactor, therefore, the reactivity control system composed of control rod, burnable poison and reserve shutdown system in Mark-II design was re-studied, and several improvements were indicated. (1) The diameter of control rods must be as large as possible because it is impossible to increase the number of control rods. (2) The accuracy in estimation of the reactivity to be compensated with control rods is important because of the mutual interference of pair control rods with the twin configuration in a fuel element. (3) The improvement of core performance in burnup is accompanied by the reduction of design margin for control rods. (4) Increase of the reactivity to be compensated with the burnable poison leads to increase of the core reactivity recovery with burnup, and the assertion of the decrease for recovery of reactivity leads to increase of the temperature dependency of reactivity compensated with control rods. (5) Reduction of reactivity to be compensated with control rods is thus limited by cancellation of the effects in the reactivity recovery and the reactivity temperature dependency. (6) The reserve shutdown system can be designed with margin under the condition of excluding the reactivity of burnup from that to be compensated. (auth.)

  3. A model for global diversity in response to temperature change over geological time scales, with reference to planktic organisms.

    Science.gov (United States)

    De Blasio, Fabio Vittorio; Liow, Lee Hsiang; Schweder, Tore; De Blasio, Birgitte Freiesleben

    2015-01-21

    There are strong propositions in the literature that abiotic factors override biotic drivers of diversity on time scales of the fossil record. In order to study the interaction of biotic and abiotic forces on long term changes, we devise a spatio-temporal discrete-time Markov process model of macroevolution featuring population formation, speciation, migration and extinction, where populations are free to migrate. In our model, the extinction probability of these populations is controlled by latitudinally and temporally varying environment (temperature) and competition. Although our model is general enough to be applicable to disparate taxa, we explicitly address planktic organisms, which are assumed to disperse freely without barriers over the Earth's oceans. While rapid and drastic environmental changes tend to eliminate many species, generalists preferentially survive and hence leave generalist descendants. In other words, environmental fluctuations result in generalist descendants which are resilient to future environmental changes. Periods of stable or slow environmental changes lead to more specialist species and higher population numbers. Simulating Cenozoic diversity dynamics with both competition and the environmental component of our model produces diversity curves that reflect current empirical knowledge, which cannot be obtained with just one component. Our model predicts that the average temperature optimum at which planktic species thrive best has declined over the Neogene, following the trend of global average temperatures. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Acute volume expansion attenuates hyperthermia-induced reductions in cerebral perfusion during simulated hemorrhage

    DEFF Research Database (Denmark)

    Schlader, Zachary J; Seifert, Thomas; Wilson, Thad E

    2013-01-01

    Hyperthermia reduces the capacity to withstand a simulated hemorrhagic challenge, but volume loading preserves this capacity. This study tested the hypotheses that acute volume expansion during hyperthermia increases cerebral perfusion and attenuates reductions in cerebral perfusion during...... infusion while hyperthermic. Primary dependent variables were mean middle cerebral artery blood velocity (MCAvmean), serving as an index of cerebral perfusion; mean arterial pressure (MAP); and cardiac output (thermodilution). During baseline, hyperthermia reduced MCAvmean (P = 0.001) by 12 ± 9% relative...

  5. Cisplatin, hyperthermia, and radiation (trimodal therapy) in patients with locally advanced head and neck tumors: A phase I-II study

    International Nuclear Information System (INIS)

    Amichetti, M.; Graiff, C.; Fellin, G.; Pani, G.; Bolner, A.; Maluta, S.; Valdagni, R.

    1993-01-01

    Hyperthermia is now being widely used to treat clinical malignancies, especially combined with radiotherapy and more rarely with chemotherapy. The combination of heat, radiation, and chemotherapy (trimodality) can lead to potent interaction. The present Phase I-II study was conducted to evaluate the feasibility and acute toxicity of a combination of cisplantin, hyperthermia, and irradiation in the treatment of superficial cervical nodal metastases from head and neck cancer. Eighteen patients with measurable neck metastases from previously untreated squamous cell head and neck tumors were entered into the trial. Therapy consisted of a conventional irradiation (total dose 70 Gy, 2 Gy five times a week) combined with a weekly administration of 20 mg/m 2 iv of cisplatin and a total of two sessions of local external microwave hyperthermia (desired temperature of 42.5 degrees C for 30 min). Feasibility of the treatment was demonstrated. Acute local toxicity was mild; no thermal blisters or ulcerations were reported and only two patients experienced local pain during hyperthermia. Cutaneous toxicity appeared greater than in previous studies with irradiation plus hyperthermia and irradiation plus cisplatin. Systematic toxicity was moderate with major toxic effects observed in three patients (World Health Organization (WHO) grade 3 anaemia). Even though it was not an aim of the study to evaluate the nodal response, they observed a complete response rate of 72.2% (95% confidence interval 51-93.4%), 16.6% of partial response and 11.1% of no change. The study confirms the feasibility of the combination of cisplantin, heat, and radiation with an acceptable toxicity profile. The trimodal therapy deserves further evaluation as a way to enhance the efficacy of irradiation in the treatment of nodal metastases from head and neck tumors. 43 refs., 3 figs., 4 tabs

  6. High doses of L-naloxone but neither D-naloxone nor beta-funaltrexamine prevent hyperthermia-induced seizures in rat pups.

    Science.gov (United States)

    Laorden, M L; Miralles, F S; Puig, M M

    1988-03-01

    The effects of the non-specific opiate antagonist L-naloxone and the inactive isomer D-naloxone, as well as the specific mu receptor antagonist beta-funaltrexamine, have been examined on hyperthermia-induced seizures in unrestrained 15 days old rats. Saline-injected animals exposed to an ambient temperature of 40 degrees C showed a gradual increase in body temperature reaching a maximum of 42 +/- 0.1 degrees C at 50 min exposure. At this time all the pups had seizures and died. Similar results were obtained when the animals were pretreated with different doses of D-naloxone and beta-funaltrexamine. Rats pretreated with L-naloxone also showed an increase in rectal temperature; but the temperature was lower than in saline-injected animals. Only high doses of L-naloxone prevented seizures and deaths. These data indicate that endogenous opioid peptides may play a role in seizures induced by hyperthermia and that receptors other than mu receptors could be involved in hyperthermia-induced seizures.

  7. Radiation therapy combined with hyperthermia in advanced cancer

    International Nuclear Information System (INIS)

    Okuma, Akiko; Terashima, Hiromi; Torii, Yoshikuni; Nakata, Hajime; Inatomi, Hisato

    1986-01-01

    Radiation therapy combined with radiofrequency (RF) hyperthermia was performed on 5 advanced cancer patients. Included were one each with urinary bladder cancer, hepatoma with left axillary node metastasis, breast cancer, tongue cancer with left cervical metastasis, and mandibular cancer. All had large tumors, which were judged to be uncontrollable by radiotherapy alone. They were treated with irradiation (Linac: 10 MV X-ray 1.8 - 2.0 Gy/day, 5 days/week), followed within an hour by RF hyperthermia once or twice a week. Partial response was obtained in the urinary bladder cancer patient. Surface overheating around the margin of electrodes occurred in all but no severe complications were observed. (author)

  8. Hypoxic cell radiosensitization by moderate hyperthermia and glucose deprivation

    International Nuclear Information System (INIS)

    Kim, J.H.; Kim, S.H.; Hahn, E.W.

    1983-01-01

    Cell culture studies were carried out to determine whether moderate hyperthermia reduces the oxygen enhancement ratio of cells under well-defined cultural conditions. Using asynchronously growing HeLa cells, the OER of cells with and without glucose was determined following exposure of cells to moderate hyperthermia, 40.5omicronC for 1 hr, immediately after X irradiation. The OER of cells with 5 mM glucose was 3.2, whereas the OER of glucose-deprived cells was reduced to 2.0. The pH of the cell culture medium was kept at 7.4 throughtout the experiments. The present finding may provide a clue toward further enhancing the radiosensitization of hypoxic cells by heat

  9. Hypoxic cell radiosensitization by moderate hyperthermia and glucose deprivation

    International Nuclear Information System (INIS)

    Kim, J.H.; Kim, S.H.; Hahn, E.W.

    1983-01-01

    Cell culture studies were carried out to determine whether moderate hyperthermia reduces the oxygen enhancement ratio of cells under well-defined cultural conditions. Using asynchronously growing HeLa cells, the OER of cells with and without glucose was determined following exposure of cells to moderate hyperthermia, 40.5 degrees C for 1 hr, immediately after X irradiation. The OER of cells with 5 mM glucose was 3.2, whereas the OER of glucose-deprived cells was reduced to 2.0. The pH of the cell culture medium was kept at 7.4 throughout the experiments. The present finding may provide a clue toward further enhancing the radiosensitization of hypoxic cells by heat

  10. Thermoseeds for interstitial magnetic hyperthermia: from bioceramics to nanoparticles

    International Nuclear Information System (INIS)

    Baeza, A; Arcos, D; Vallet-Regí, M

    2013-01-01

    The development of magnetic materials for interstitial hyperthermia treatment of cancer is an ever evolving research field which provides new alternatives to antitumoral therapies. The development of biocompatible magnetic materials has resulted in new biomaterials with multifunctional properties, which are able to adapt to the complex scenario of tumoral processes. Once implanted or injected in the body, magnetic materials can behave as thermoseeds under the effect of AC magnetic fields. Magnetic bioceramics aimed to treat bone tumors and magnetic nanoparticles are among the most studied thermoseeds, and supply different solutions for the different scenarios in cancerous processes. This paper reviews some of the biomaterials used for bone cancer treatment and skeletal reinforcing, as well as the more complex topic of magnetic nanoparticles for intracellular targeting and hyperthermia. (topical review)

  11. A thermal monitoring sheet with low influence from adjacent waterbolus for tissue surface thermometry during clinical hyperthermia.

    Science.gov (United States)

    Arunachalam, Kavitha; Maccarini, Paolo F; Stauffer, Paul R

    2008-10-01

    This paper presents a complete thermal analysis of a novel conformal surface thermometer design with directional sensitivity for real-time temperature monitoring during hyperthermia treatments of large superficial cancer. The thermal monitoring sheet (TMS) discussed in this paper consists of a 2-D array of fiberoptic sensors embedded between two layers of flexible, low-loss, and thermally conductive printed circuit board (PCB) film. Heat transfer across all interfaces from the tissue surface through multiple layers of insulating dielectrics surrounding the small buried temperature sensor and into an adjacent temperature-regulated water coupling bolus was studied using 3-D thermal simulation software. Theoretical analyses were carried out to identify the most effective differential TMS probe configuration possible with commercially available flexible PCB materials and to compare their thermal responses with omnidirectional probes commonly used in clinical hyperthermia. A TMS sensor design that employs 0.0508-mm Kapton MTB and 0.2032-mm Kapton HN flexible polyimide films is proposed for tissue surface thermometry with low influence from the adjacent waterbolus. Comparison of the thermal simulations with clinical probes indicates the new differential TMS probe design to outperform in terms of both transient response and steady-state accuracy in selectively reading the tissue surface temperature, while decreasing the overall thermal barrier of the probe between the coupling waterbolus and tissue surface.

  12. Impact of localized microwave hyperthermia on the pH-distribution in malignant tumors

    International Nuclear Information System (INIS)

    Vaupel, P.

    1982-01-01

    The impact of localized microwave hyperthermia (2.45 GHz) on the tissue pH-distribution was investigated in C3H mause mammary tumors. The measurements were performed in microareas of the tissue using pH-microelectrodes with tip diameters of approximately 1 μm. pH-readings during localized heating revealed that tissue temperatures exceeding 42 0 C were followed by a pronounced pH-drop in tumors with a negligible amount of necrosis. Tissue pH-values measured immediately after heating (43 0 C for 60 min) were lowered by an average of 0.54 +- 0.19 pH-units as compared with preheating data (2p [de

  13. RGD-conjugated iron oxide magnetic nanoparticles for magnetic resonance imaging contrast enhancement and hyperthermia.

    Science.gov (United States)

    Zheng, S W; Huang, M; Hong, R Y; Deng, S M; Cheng, L F; Gao, B; Badami, D

    2014-03-01

    The purpose of this study was to develop a specific targeting magnetic nanoparticle probe for magnetic resonance imaging and therapy in the form of local hyperthermia. Carboxymethyl dextran-coated ultrasmall superparamagnetic iron oxide nanoparticles with carboxyl groups were coupled to cyclic arginine-glycine-aspartic peptides for integrin α(v)β₃ targeting. The particle size, magnetic properties, heating effect, and stability of the arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide were measured. The arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide demonstrates excellent stability and fast magneto-temperature response. Magnetic resonance imaging signal intensity of Bcap37 cells incubated with arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide was significantly decreased compared with that incubated with plain ultrasmall superparamagnetic iron oxide. The preferential uptake of arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide by target cells was further confirmed by Prussian blue staining and confocal laser scanning microscopy.

  14. Magnetic study of iron-containing carbon nanotubes: Feasibility for magnetic hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Krupskaya, Y. [Leibniz-Institute for Solid State and Materials Research IFW Dresden, 01171 Dresden (Germany)], E-mail: y.krupskaya@ifw-dresden.de; Mahn, C.; Parameswaran, A. [Leibniz-Institute for Solid State and Materials Research IFW Dresden, 01171 Dresden (Germany); Taylor, A.; Kraemer, K. [Department of Urology, Dresden University of Technology, 01307 Dresden (Germany); Hampel, S.; Leonhardt, A.; Ritschel, M.; Buechner, B.; Klingeler, R. [Leibniz-Institute for Solid State and Materials Research IFW Dresden, 01171 Dresden (Germany)

    2009-12-15

    We present a detailed magnetic study of iron containing carbon nanotubes (Fe-CNT), which highlights their potential for contactless magnetic heating in hyperthermia cancer treatment. Magnetic field dependent AC inductive heating experiments on Fe-CNT dispersions show a substantial temperature increase of Fe-CNT dispersions in applied AC magnetic fields. DC and AC magnetization studies have been done in order to elucidate the heating mechanism. We observe a different magnetic response of Fe-CNT powder compared to Fe-CNT dispersed in aqueous solution, e.g., ferromagnetic Fe-CNT in powder do not show any hysteresis when being dispersed in liquid. Our data indicate the motion of Fe-CNT in liquid in applied magnetic fields.

  15. Intraoperative radio-frequency capacitive hyperthermia and radiation therapy for unresectable pancreatic cancer

    International Nuclear Information System (INIS)

    Nakazawa, M.; Yamashita, T.; Hashida, I.

    1988-01-01

    The authors have initiated intraoperative radiation therapy (IORT) and intraoperative radio-frequency capacitive hyperthermia (IOHT) for unresectable pancreatic cancer. After gastric (corpus) resection, IORT and IOHT were conducted and gastro-duodenostomy was performed IORT was delivered with 12 meV electron (25 Gy) and 10 MV Linac x-ray (7.5 Gy). IOHT was done with 13.56 MHz capacitive equipment aiming 43 0 C for over 30 min along with concurrent administration of 500 mg 5-FU. Five cases were heated by the conventional method and two additional cases were heated with a newly fabricated applicator. Attained temperatures monitored directly from tumor were 38.5 0 C-44.3 0 C (over 43 0 C in four cases, 40 0 C in one case, and below 40 0 C in two cass.) Pain relief was achieved in most cases. Using the new applicators, the authors could avoid unexpected hot spots and insufficient heating

  16. [Multiorgan failure associated with hyperthermia in an infant with Prader-Willi syndrome. case report].

    Science.gov (United States)

    Donoso, Alejandro; Arriagada, Daniela; Campbell, Stephanie; Cruces, Pablo

    2013-10-01

    Heat stroke is a medical emergency characterized primarily by an elevated core temperature associated with a systemic inflammatory response, which causes multiple organ dysfunction in which encephalopathy predominates. If it is not early treated has high mortality. The Prader-Willi syndrome is a multisystem genetic disorder secondary to an abnormality in long arm chromosome 15 (15q11-q13), characterized by neonatal central hypotonia, developmental delay, hypogonadism, hyperphagia and obesity. These patients are susceptible to developing thermoregulatory problems. We report the case of a 5-month-old infant, in whom a diagnosis of Prader-Willi syndrome was established in the course of a febrile episode without known focus, who developed multiorganic failure and rhabdomyolysis secondary to hyperthermia.

  17. Water chemistry in nuclear power stations with high-temperature reactors with particular reference to the AVR

    International Nuclear Information System (INIS)

    Nieder, R.; Resch, G.

    1976-01-01

    The water-steam cycle of a nuclear power plant with a helium-cooled high-temperature reactor differs in design data significantly and extensively from the corresponding cycles of light-water-cooled nuclear reactors and resembles to a great extent the water-steamcycle of a modern conventional power plant. The radioactive constituents of the water-steam cycle can be satisfactorily removed apart from Tritium by means of a pre-coat filter with powder-resisn, as comprehensive experiments have demonstrated. (orig.) [de

  18. Hyperthermia and Use of Antipyretics in Pediatric Practice

    Directory of Open Access Journals (Sweden)

    Yu.V. Marushko

    2013-08-01

    Full Text Available The article deals with problem of hyperthermia in pediatric practice. There are given the peculiarities of fever types, recommendations on management by physician who provides care for a child with a fever, recommendations on the definition of the category of patients who should be administered with antipyretic agent. The authors provide evidence-based data on the benefits of ibuprofen (Nurofen® for children as the hypothermic therapy in children with fever.

  19. Design and Fabrication of Low Cost Thick Film pH Sensor using Silver Chlorinated Reference Electrodes with Integrated Temperature Sensor

    Directory of Open Access Journals (Sweden)

    Wiranto Goib

    2016-01-01

    Full Text Available This paper describes the design and fabrication of thick film pH sensor, in which the reference electrode has been formed by chlorination of Ag using FeCl3. The process was aimed to replace Ag/AgCl paste commonly used as reference electrodes. Fabricated using thick film screen printing technology on Al2O3 substrate, the pH sensor showed a measured sensitivity of -52.97, -53.17 and -53.68 mV/pH at 25°C, 45°C, and 65°C, respectively. The measured values were close to the theoretical Nernstian slope of -59 mV/pH 25°C.The sensor was also designed with an integrated Ruthenium based temperature sensor for future temperature compensation. The measured resistance temperature characteristics showed a linear reasponse over the range of 25 – 80°C. This miniaturised planar sensor should find wide application, especially in field water quality monitoring, replacing their glass type counterparts.

  20. Isotope effect in monolayer, localised, immobilised adsorption with special reference to neon adsorption on porous glass at cryogenic temperatures

    International Nuclear Information System (INIS)

    Srisaila, S.; Bajpai, M.B.

    1980-01-01

    Using statistical mechanics, a general formula for the separation factor of two isotopes between gas and adsorbate phases in a monolayer, localised, immobile adsorption on a heterogeneous surface, is derived. Special forms of this are discussed for which the familiar Bigeleisen form is one. Purer, Kalplan and Smith, in their work on neon isotopes separation by gas chromatography through porous glass column at cryogenic temperatures, have reported that the separation factor first increased and then decreased as the temperature was decreased, whereas monotonic increase was the normally expected behaviour. Moiseyev has attempted to explain the anomaly after assuming two types of adsorption sites. The present theory gives the conditions in which monotonic and nonmonotonic variations can occur and after making some assumptions, the experimental curve of Purer et al could be reproduced computationally using one form of the general expression. This theoretical treatment highlights the importance of both potential energy and force constant in isotope effect whereas it is only the potential energy that is much involved in most adsorption studies. (auth.)

  1. Gelatine-assisted synthesis of magnetite nanoparticles for magnetic hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Alves, André F.; Mendo, Sofia G. [Universidade de Lisboa, Centro de Química e Bioquímica, Faculdade de Ciências (Portugal); Ferreira, Liliana P. [Universidade de Lisboa, Biosystems and Integrative Sciences Institute, Faculdade de Ciências (Portugal); Mendonça, Maria Helena [Universidade de Lisboa, Centro de Química e Bioquímica, Faculdade de Ciências (Portugal); Ferreira, Paula [University of Aveiro, Department of Materials and Ceramic Engineering, CICECO - Aveiro Institute of Materials (Portugal); Godinho, Margarida; Cruz, Maria Margarida [Universidade de Lisboa, Biosystems and Integrative Sciences Institute, Faculdade de Ciências (Portugal); Carvalho, Maria Deus, E-mail: mdcarvalho@ciencias.ulisboa.pt [Universidade de Lisboa, Centro de Química e Bioquímica, Faculdade de Ciências (Portugal)

    2016-01-15

    Magnetite nanoparticles were synthesized by the co-precipitation method exploring the use of gelatine and agar as additives. For comparison, magnetite nanoparticles were also prepared by standard co-precipitation, by co-precipitation with the addition of a surfactant (sodium dodecyl sulphate) and by the thermal decomposition method. The structure and morphology of the synthesized nanoparticles were investigated by powder X-ray diffraction and transmission electron microscopy. Their magnetic properties were studied by SQUID magnetometry and {sup 57}Fe Mössbauer spectroscopy. The nanoparticles potential for applications in magnetic hyperthermia was evaluated through heating efficiency under alternating magnetic field. The results show that all synthesis methods produce Fe{sub 3−x}O{sub 4} nanoparticles with similar sizes. The nanoparticles synthesized in the gelatine medium display the narrowest particle size distribution, the lowest oxidation degree, one of the highest saturation magnetization values and the best hyperthermia efficiency, proving that this gelatine-assisted synthesis is an efficient, environmental friendly, and low-cost method to produce magnetite nanoparticles. Graphical Abstract: A new gelatine-assisted method is an efficient and low-cost way to synthesize magnetite nanoparticles with enhanced magnetic hyperthermia.

  2. Bi-functional properties of Fe3O4@YPO4:Eu hybrid nanoparticles: hyperthermia application.

    Science.gov (United States)

    Prasad, A I; Parchur, A K; Juluri, R R; Jadhav, N; Pandey, B N; Ningthoujam, R S; Vatsa, R K

    2013-04-14

    Magnetic nanoparticles based hyperthermia therapy is a possible low cost and effective technique for killing cancer tissues in the human body. Fe3O4 and Fe3O4@YPO4:5Eu hybrid magnetic nanoparticles are prepared by co-precipitation method and their average particle sizes are found to be ∼10 and 25 nm, respectively. The particles are spherical, non-agglomerated and highly dispersible in water. The crystallinity of as-prepared YPO4:5Eu sample is more than Fe3O4@YPO4:5Eu hybrid magnetic nanoparticles. The chemical bonds interaction between Fe3O4 and YPO4:5Eu is confirmed through FeO-P. The magnetization of hybrid nanocomposite shows magnetization Ms = 11.1 emu g(-1) with zero coercivity (measured at 2 × 10(-4) Oe) at room temperature indicating superparamagnetic behaviour. They attain hyperthermia temperature (~42 °C) under AC magnetic field showing characteristic induction heating of the prepared nanohybrid and they will be potential material for biological application. Samples produce the red emission peaks at 618 nm and 695 nm, which are in range of biological window. The quantum yield of YPO4:5Eu sample is found to be 12%. Eu(3+) present on surface and core could be distinguished from luminescence decay study. Very high specific absorption rate up to 100 W g(-1) could be achieved. The intracellular uptake of nanocomposites is found in mouse fibrosarcoma (Wehi 164) tumor cells by Prussian blue staining.

  3. Computerized portable microwave hyperthermia quality assurance kit

    International Nuclear Information System (INIS)

    Cheung, A.Y.; Neyzari, A.

    1985-01-01

    A computerized quality assurance kit to provide precise measurement and calibration of microwave power and temperature, as well as capabilities to map SAR (Specific absorption rate) distribution in phantoms; and survey of hazardous microwave leakage has been designed. The kit is also capable of performing corelation studies on the relationship between SAR and net microwave power delivered at various anatomical sites. The kit consists of a portable microcomputer, a time-multiplexed A/D converter, a 4-channel dual directional microwave power monitor, a 4-channel thin-wire thermocouple thermometry system, an electronic thermal calibrator, a microwave leakage hazard survey meter, and a dynamic phantom tank for dosimetric analysis. Comparative performance studies were made against NBS-traceable power and temperature standards, non-perturbing optical temperature sensors, and established power and temperature measurement devices. The test results indicate that this instrument is providing its user with measurement accuracy of 0.1 0 C in temperature, 10% accuracy in power. The thin-wire thermocouple, with computer assisted error compensation, performs equally well in a strong microwave field in comparison with non-perturbing optical temperature sensors

  4. Spectrally narrow, long-term stable optical frequency reference based on a Eu3+:Y2SiO5 crystal at cryogenic temperature.

    Science.gov (United States)

    Chen, Qun-Feng; Troshyn, Andrei; Ernsting, Ingo; Kayser, Steffen; Vasilyev, Sergey; Nevsky, Alexander; Schiller, Stephan

    2011-11-25

    Using an ultrastable continuous-wave laser at 580 nm we performed spectral hole burning of Eu(3+):Y(2)SiO(5) at a very high spectral resolution. The essential parameters determining the usefulness as a macroscopic frequency reference, linewidth, temperature sensitivity, and long-term stability, were characterized using a H-maser stabilized frequency comb. Spectral holes with a linewidth as low as 6 kHz were observed and the upper limit of the drift of the hole frequency was determined to be 5±3 mHz/s. We discuss the necessary requirements for achieving ultrahigh stability in laser frequency stabilization to these spectral holes.

  5. Improvement of locoregional hyperthermia treatments of oesophageal cancer using treatment planning

    International Nuclear Information System (INIS)

    Kok, H.P.; Haaren Van, P.M.A.; Kamer Van de, J.B.; Zum Voerde Sive Voerding, P.J.; Wiersma, J.; Hulshof, M.C.C.M; Geijsen, E.D.; Crezee, J.

    2005-01-01

    Full text: The thermal dose achieved in the clinic often remains too low due to the incidence of treatment limiting hot spots, which are difficult to avoid intuitively due to the large number of degrees of freedom (amplitudes and phases) of the heating device. To improve hyperthermia treatments of oesophagus carcinoma patients with the 70 MHz AMC-4 waveguide system we performed hyperthermia treatment planning (HTP) with high resolution temperature based optimization. With this optimization we obtain amplitude (A) and phase (p) settings for the antennas for optimal tumor heating (> 43 o C) while preventing hot spots in normal tissue ( o C) and maintaining the spinal cord temperature below 40 o C to prevent neurotoxicity. With the mixed A/P settings the highest absolute ΔT's were achieved, while the ratio was not much different from the other two configurations. This implies that with these settings the same tumor heating can be obtained with less applied power, resulting in more efficient heating. The fact that the combined numerical A/clinical P settings resulted in the highest absolute temperature rises in the oesophagus might be due to the difference in patient positioning between the planning and the actual treatment, since the location of the SAR focus in the tumor is constructed mainly by phase steering. The temperature rise near the spinal cord depends mainly on the power of the top antenna. The correlation coefficient was R=0.37, which was considerably higher than the correlation with the powers or phases of the other antennas. The temperature rise in the oesophagus depends mainly on the power of the top and bottom antenna together. The correlation coefficient was only R=0.12 but this was still more than 2 times higher than the correlation with the power of the left and right antenna. The relation between the temperature rise due to a power pulse of 30 seconds and the achieved steady state temperature was more or less linear, implying a higher T 90 and T 50

  6. Improvement of locoregional hyperthermia treatments of oesophageal cancer using treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Kok, H P; Haaren Van, P M.A.; Kamer Van de, J B; Zum Voerde Sive Voerding, P.J.; Wiersma, J; Hulshof, M C.C.M; Geijsen, E D; Crezee, J [Department of Radiation Oncology, Academic Medical Center, University of Amsterdam (Netherlands)

    2005-07-01

    Full text: The thermal dose achieved in the clinic often remains too low due to the incidence of treatment limiting hot spots, which are difficult to avoid intuitively due to the large number of degrees of freedom (amplitudes and phases) of the heating device. To improve hyperthermia treatments of oesophagus carcinoma patients with the 70 MHz AMC-4 waveguide system we performed hyperthermia treatment planning (HTP) with high resolution temperature based optimization. With this optimization we obtain amplitude (A) and phase (p) settings for the antennas for optimal tumor heating (> 43 {sup o}C) while preventing hot spots in normal tissue (< 42 {sup o}C) and maintaining the spinal cord temperature below 40 {sup o}C to prevent neurotoxicity. With the mixed A/P settings the highest absolute {delta}T's were achieved, while the ratio was not much different from the other two configurations. This implies that with these settings the same tumor heating can be obtained with less applied power, resulting in more efficient heating. The fact that the combined numerical A/clinical P settings resulted in the highest absolute temperature rises in the oesophagus might be due to the difference in patient positioning between the planning and the actual treatment, since the location of the SAR focus in the tumor is constructed mainly by phase steering. The temperature rise near the spinal cord depends mainly on the power of the top antenna. The correlation coefficient was R=0.37, which was considerably higher than the correlation with the powers or phases of the other antennas. The temperature rise in the oesophagus depends mainly on the power of the top and bottom antenna together. The correlation coefficient was only R=0.12 but this was still more than 2 times higher than the correlation with the power of the left and right antenna. The relation between the temperature rise due to a power pulse of 30 seconds and the achieved steady state temperature was more or less linear

  7. Regional hyperthermia combined with chemotherapy in paediatric, adolescent and young adult patients: current and future perspectives

    International Nuclear Information System (INIS)

    Seifert, Georg; Budach, Volker; Keilholz, Ulrich; Wust, Peter; Eggert, Angelika; Ghadjar, Pirus

    2016-01-01

    Here we evaluate the current status of clinical research on regional hyperthermia (RHT) in combination with chemotherapy or radiation therapy in paediatric oncology. Data were identified in searches of MEDLINE, Current Contents, PubMed, and references from relevant articles using medical subject headings including hyperthermia, cancer, paediatric oncology, children, radiation therapy and chemotherapy. Currently, only two RHT centres exist in Europe which treat children. Clinical RHT research in paediatric oncology has as yet been limited to children with sarcomas and germ cell tumours that respond poorly to or recur after chemotherapy. RHT is a safe and effective treatment delivering local thermic effects, which may also stimulate immunological processes via heat-shock protein reactions. RHT is used chiefly in children and adolescents with sarcomas or germ cell tumours located in the abdomino-pelvic region, chest wall or extremities to improve operability or render the tumour operable. It could potentially be combined with radiation therapy in a post-operative R1 setting where more radical surgery is not possible or combined with chemotherapy instead of radiation therapy in cases where the necessary radiation dose is impossible to achieve or would have mutilating consequences. RHT might also be an option for chemotherapy intensification in the neoadjuvant first-line treatment setting for children and adolescents, as was recently reflected in the promising long-term outcome data in adults with high-risk soft tissue sarcomas (EORTC 62961/ESHO trial). The limited data available indicate that combining RHT with chemotherapy is a promising option to treat germ cell tumours and, potentially, sarcomas. RHT may also be beneficial in first-line therapy in children, adolescents and young adults. The research should focus on optimising necessary technical demands and then initiate several clinical trials incorporating RHT into interdisciplinary treatment of children

  8. Eye and Ear Temperature Using Infrared Thermography Are Related to Rectal Temperature in Dogs at Rest or With Exercise.

    Science.gov (United States)

    Zanghi, Brian M

    2016-01-01

    Rectal body temperature (BT) has been documented in exercising dogs to monitor thermoregulation, heat stress risk, and performance during physical activity. Eye (BT eye ) and ear (BT ear ) temperature measured with infrared thermography (IRT) were compared to rectal (BT rec ) temperature as the reference method and assess alternative sites to track hyperthermia, possibly to establish BT eye IRT as a passive and non-contact method. BT measures were recorded at 09:00, 11:30, 12:30, and 02:30 from Labrador Retrievers ( N  = 16) and Beagles ( N  = 16) while sedentary and with 30-min play-exercise (pre- and 0, 15, 30-min post-exercise). Total exercise locomotor activity counts were recorded to compare relative intensity of play-exercise between breeds. BT rec , BT eye , and BT ear were measured within 5 min of the target time. Each BT method was analyzed by analysis of variance for main effects of breed and time. Method differences were compared using Bland-Altman plots and linear regression. Sedentary BT differed by breed for BT rec ( p  dogs with sedentary or exercise activity. The relationship between BT eye and BT rec improved when monitoring exercise hyperthermia ( r  = 0.674) versus measures at rest ( r  = 0.381), whereas BT ear was significantly related to BT rec regardless of activity ( r  = 0.615-0.735). Although BT readings were significantly related, method bias ( p  temperature and enables effective monitoring of BT changes at rest, with exercise, and between breeds. However, ear, and not eye, temperature is a better reflection of rectal temperature.

  9. Improving immunological tumor microenvironment using electro-hyperthermia followed by dendritic cell immunotherapy

    International Nuclear Information System (INIS)

    Tsang, Yuk-Wah; Huang, Cheng-Chung; Yang, Kai-Lin; Chi, Mau-Shin; Chiang, Hsin-Chien; Wang, Yu-Shan; Andocs, Gabor; Szasz, Andras; Li, Wen-Tyng; Chi, Kwan-Hwa

    2015-01-01

    The treatment of intratumoral dentritic cells (DCs) commonly fails because it cannot evoke immunity in a poor tumor microenvironment (TME). Modulated electro-hyperthermia (mEHT, trade-name: oncothermia) represents a significant technological advancement in the hyperthermia field, allowing the autofocusing of electromagnetic power on a cell membrane to generate massive apoptosis. This approach turns local immunogenic cancer cell death (apoptosis) into a systemic anti-tumor immune response and may be implemented by treatment with intratumoral DCs. The CT26 murine colorectal cancer model was used in this investigation. The inhibition of growth of the tumor and the systemic anti-tumor immune response were measured. The tumor was heated to a core temperature of 42 °C for 30 min. The matured synergetic DCs were intratumorally injected 24 h following mEHT was applied. mEHT induced significant apoptosis and enhanced the release of heat shock protein70 (Hsp70) in CT26 tumors. Treatment with mEHT-DCs significantly inhibited CT26 tumor growth, relative to DCs alone or mEHT alone. The secondary tumor protection effect upon rechallenging was observed in mice that were treated with mEHT-DCs. Immunohistochemical staining of CD45 and F4/80 revealed that mEHT-DC treatment increased the number of leukocytes and macrophages. Most interestingly, mEHT also induced infiltrations of eosinophil, which has recently been reported to be an orchestrator of a specific T cell response. Cytotoxic T cell assay and ELISpot assay revealed a tumor-specific T cell activity. This study demonstrated that mEHT induces tumor cell apoptosis and enhances the release of Hsp70 from heated tumor cells, unlike conventional hyperthermia. mEHT can create a favorable tumor microenvironment for an immunological chain reaction that improves the success rate of intratumoral DC immunotherapy. The online version of this article (doi:10.1186/s12885-015-1690-2) contains supplementary material, which is available to

  10. Meteorological Reference Years of Daily Mean Temperature during the Sunlight Time; Anos Tipos de Temperaturas Medias Diarias durante las Horas de Sol

    Energy Technology Data Exchange (ETDEWEB)

    Marchante Jimenez, M.; Ramirez Santigosa, L.N.; Mora Lopez, L.; Sidrach de Cardona Ortin, M.

    2002-07-01

    In this work the characterization of the daily mean temperature during the sunlight time has been analyzed. An algorithm for the hourly series generation from extreme daily values has been applied to evaluate the daily mean temperature during the sunlight time. A generic algorithm has been enounced as a function of the sunrise time. This algorithm allows taking into account the fractions related to the sunrise and sunset hours. This methodology has been applied in data from 45 Spanish stations, uniformly distributed in the Iberian Peninsula. Data for a period of 14 years has been used in most of locations, and once the interest variable has been calculated, the meteorological reference year of the daily mean temperature during the sunlight time has been evaluated in each stations. The next step is the evaluation of the daily mean temperature during the sunlight time in any point into the zone of evaluation, not only in the measured stations. >From the result data in each measured station, an geographic information system has been used in order to calculate the interpolation, obtaining maps with a data each 5 km for each of the 365 days of the year. Then, this results can be superposed with the solar radiation evaluation obtaining the input data for the sizing of the photovoltaic grid connected system in any point of the Spanish geography. (Author) 8 refs.

  11. An ultrasound system for simultaneous ultrasound hyperthermia and photon beam irradiation

    International Nuclear Information System (INIS)

    Straube, William L.; Moros, Eduardo G.; Low, Daniel A.; Klein, Eric E.; Willcut, Virgil M.; Myerson, Robert J.

    1996-01-01

    Purpose: An existing ultrasound system has been adapted for simultaneous use with external photon beam irradiation. The system is being used to investigate the potential for increased biological benefit of simultaneously combined hyperthermia and external beam irradiation with currently achievable temperature distributions. Methods and Materials: An existing clinical ultrasound system has been modified for simultaneous operation with a 60 Co teletherapy machine. The generator, thermometry system, computer, and applicators are located inside the treatment room, while the monitor and system control are located at the control console. Two approaches have been used clinically to combine the two modalities. In the first approach, an en-face setup is used in which the ultrasound beam and the photon beam travel through the same window of entry to the tumor. This is achieved by a reflecting system designed to deflect the ultrasound to the tumor while positioning the ultrasound transducer outside the radiation beam. The reflecting system consists of water and water-equivalent materials except for a 1 mm sheet of polished brass that is used as the reflector. The relative pressure fields were measured in water at the same distance from the ultrasound source using a scanning hydrophone with and without the reflector at the two operating frequencies of the device (1.0 and 3.4 MHz) for two applicators. Radiation dosimetry measurements were performed to determine the relationship between 60 Co irradiation through the reflector and absorbed dose. In the second approach the ultrasound and the radiation beam travel into the tumor from different windows of entry such that the radiation beam passes through no portion of the water bolus prior to entering the patient. We have termed this approach the orthogonal approach. For both approaches, the radiation fraction is given in the middle of an uninterrupted 60-min hyperthermia treatment. Results: The system modifications did not impair

  12. Combined anti-tumor therapeutic effect of targeted gene, hyperthermia, radionuclide brachytherapy in breast carcinoma

    International Nuclear Information System (INIS)

    Chen Daozhen; Tang Qiusha; Xiang Jingying; Xu Fei; Zhang Li; Wang Junfeng

    2011-01-01

    Objective: To investigate the antitumor therapeutic effect of combined therapy of magnetic induction heating by nano-magnetic particles, herpes simplex virus thymidine kinase gene (HSV-tk suicide gene) and internal radiation in mice bearing MCF-7 breast carcinoma. Methods: The transfection reagents, plasmids heat shock protein-HSV-tk (pHSP-HSV-tk), ferroso-ferric oxide nano-magnetic fluid flow and 188 Re-ganciclovir-bovine serum albumin-nanopaticles (GCV-BSA-NP) were prepared. The heating experiments in vivo were carried out using ferroso-ferric oxide nano-magnetic fluid flow. Sixty mice tumor models bearing MCF-7 breast carcinoma were established and randomly divided into six groups. Group A was the control group, B was gene transfection therapy group, C was hyperthermia group, D was gene transfection therapy combined with radionuclide brachytherapy group, E was gene therapy combined with hyperthermia group, and F was gene therapy, hyperthermia combined with radionuclide brachytherapy group. The tumor growth, tumor mass and histopathological changes were evaluated. The expression of HSV-tk in the groups of B, D, E and F was detected by RT-PCR. Poisson distribution and one-way analysis of variance (ANOVA) were used for statistical analysis by SPSS 10.0 software. Results: In the animal heating experiments, the temperature of tumor increased up to 39.6 degree C, 43.2 degree C, and 48.1 degree C quickly with different injected doses (2, 4 and 6 mg respectively) of nano-magnetic particles and maintained for 40 min. The temperature of tumor tissue reduced to 36.8 degree C, 37.5 degree C and 37.8 degree C in 10 min when alternating magnetic field (AMF) stopped. The tumor mass in Groups C ((452.50±30.29) mg), D ((240.98±35.32)mg), E((231.87±27.41) mg) and F ((141.55±23.78) mg) were much lower than that in Group A ((719.12±22.65) mg) (F=800.07, P<0.01), with the most significant treatment effect in Group F.The tumor mass in Group B((684.05±24.02) mg) was higher than

  13. Peculiarities of tumor blood supply and their role in radiotherapy, hyperthermia and hyperglycemia

    International Nuclear Information System (INIS)

    Kozin, S.V.; Furmanchuk, A.V.

    1986-01-01

    Development regularities and functional peculiarities of tumor microcirculatory channel (MCC) are considered. The role of microcirculation changes under radiotherapy and it's combinations with hyperthermia and hyperglycemia is estimated. The conclusion is drawn, that MCC reactions play a substantial role in realization of hyperthermia and hyperglycemia radiomodifying action

  14. A case of malignant hyperthermia captured by an anesthesia information management system.

    Science.gov (United States)

    Maile, Michael D; Patel, Rajesh A; Blum, James M; Tremper, Kevin K

    2011-04-01

    Many cases of malignant hyperthermia triggered by volatile anesthetic agents have been described. However, to our knowledge, there has not been a report describing the precise changes in physiologic data of a human suffering from this process. Here we describe a case of malignant hyperthermia in which monitoring information was frequently and accurately captured by an anesthesia information management system.

  15. Study on intraoperative radiotherapy applying hyperthermia together with radiation sensitizers for progressive local carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Abe, M; Takahashi, M; Ono, K; Hiraoka, M [Kyoto Univ. (Japan). Faculty of Medicine

    1980-08-01

    Intraoperative radiotherapy for gastric cancer, colonic cancer, pancreatic cancer, cancer of the biliary tract, prostatic carcinoma, cerebral tumor, tumor of soft tissues, and osteosarcoma and its clinical results were described. Basic and clinical studies on effects of both hyperthermia and radiation sensitizers to elevate radiation sensitivity were also described, because effects of intraoperative radiotherapy were raised by applying hyperthermia and hypoxic cell sensitizers.

  16. A case report of suspected malignant hyperthermia where patient survived the episode

    OpenAIRE

    Iqbal, Asif; Badoo, Shoaib; Naqeeb, Ruqsana

    2017-01-01

    Malignant hyperthermia is rare inherited disorder in our part of the world; there are only few cases reported in literature in India who were suspected of having this condition. The overall incidence of malignant hyperthermia during general anesthesia is estimated to range from 1: 5000 to 1: 50,000–100,000 and mortality rate is estimated to be

  17. Comprehensive inter-laboratory calibration of reference materials for δ18O versus VSMOW using various on-line high-temperature conversion techniques

    Science.gov (United States)

    Brand, Willi A.; Coplen, Tyler B.; Aerts-Bijma, Anita T.; Bohlke, John Karl; Gehre, Matthias; Geilmann, Heike; Groning, Manfred; Jansen, Henk G.; Meijer, Harro A. J.; Mroczkowski, Stanley J.; Qi, Haiping; Soergel, Karin; Stuart-Williams, Hilary; Weise, Stephan M.; Werner, Roland A.

    2009-01-01

    Internationally distributed organic and inorganic oxygen isotopic reference materials have been calibrated by six laboratories carrying out more than 5300 measurements using a variety of high-temperature conversion techniques (HTC) in an evaluation sponsored by the International Union of Pure and Applied Chemistry (IUPAC). To aid in the calibration of these reference materials, which span more than 125‰, an artificially enriched reference water (δ18O of +78.91‰) and two barium sulfates (one depleted and one enriched in 18O) were prepared and calibrated relative to VSMOW2 and SLAP reference waters. These materials were used to calibrate the other isotopic reference materials in this study, which yielded:Reference materialδ18O and estimated combined uncertainty IAEA-602 benzoic acid+71.28 ± 0.36‰USGS35 sodium nitrate+56.81 ± 0.31‰IAEA-NO-3 potassium nitrate+25.32 ± 0.29‰IAEA-601 benzoic acid+23.14 ± 0.19‰IAEA-SO-5 barium sulfate+12.13 ± 0.33‰NBS 127 barium sulfate+8.59 ± 0.26‰VSMOW2 water0‰IAEA-600 caffeine−3.48 ± 0.53‰IAEA-SO-6 barium sulfate−11.35 ± 0.31‰USGS34 potassium nitrate−27.78 ± 0.37‰SLAP water−55.5‰The seemingly large estimated combined uncertainties arise from differences in instrumentation and methodology and difficulty in accounting for all measurement bias. They are composed of the 3-fold standard errors directly calculated from the measurements and provision for systematic errors discussed in this paper. A primary conclusion of this study is that nitrate samples analyzed for δ18O should be analyzed with internationally distributed isotopic nitrates, and likewise for sulfates and organics. Authors reporting relative differences of oxygen-isotope ratios (δ18O) of nitrates, sulfates, or organic material should explicitly state in their reports the δ18O values of two or more internationally distributed nitrates (USGS34, IAEA-NO-3, and USGS35), sulfates (IAEA-SO-5, IAEA

  18. The combination of hyperthermia or chemotherapy with gimeracil for effective radiosensitization

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, M.; Sakata, K.; Someya, M.; Hareyama, M. [Sapporo Medical Univ. (Japan). Dept. of Radiology; Matsumoto, Y. [Tokyo Institute of Technology, Tokyo (Japan). Research Laboratory for Nuclear Reactors; Tauchi, H. [Ibaraki Univ. (Japan). Dept. of Environmental Sciences; Fukushima, M. [Taiho Pharmaceutical Co., Ltd., Tokushima (Japan). Pharmacokinetics Research Lab.

    2012-03-15

    5-chloro-2,4-dihydroxypyridine (gimeracil) is a component of the oral fluoropyrimidine derivative S-1. Gimeracil was originally added to S-1 to yield prolonged 5-fluorouracil (5-FU) concentrations in serum and tumor tissues by inhibiting dihydropyrimidine dehydrogenase, which degrades 5-FU. We previously demonstrated that gimeracil enhances the efficacy of radiotherapy through the suppression of homologous recombination (HR) in DNA double strand repair. The goal of this paper was to examine the effects of gimeracil on the sensitivity of anticancer drugs and hyperthermia in order to obtain effective radiosensitization. Various cell lines, including DLD 1 (human colon carcinoma cells) and cells deficient in HR or nonhomologous end-joining (NHEJ), were used in clonogenic assays. The survival of these cells after various treatments (e.g., drug treatment, heat treatment, and radiation) was determined based on their colony-forming ability. Gimeracil enhanced cell-killing effects of camptothecin (CPT), 5-FU, and hydroxyurea. Gimeracil sensitized effects of CPT or 5-FU to cells deficient in HR or NHEJ to a similar extent as in other cells (DLD1 and a parent cell), indicating that its sensitizing mechanisms may be different from inhibition of HR or NHEJ. Combination of gimeracil and CPT or 5-FU sensitized radiation more effectively than each modality alone. Gimeracil also enhanced heat sensitivity at 42 C or more. The degree of heat sensitization with gimeracil increased as the temperature increased, and the combination of gimeracil and heat-sensitized radiation was more effective than each modality alone. Gimeracil enhanced sensitivity of CPT, 5-FU, and hyperthermia. Combination of these modalities sensitized radiation more efficiently than each modality alone.

  19. Effect of Passive Hyperthermia on Working Memory Resources during Simple and Complex Cognitive Tasks

    Directory of Open Access Journals (Sweden)

    Nadia Gaoua

    2018-01-01

    Full Text Available The aim of this study was to verify the hypothesis that hyperthermia represents a cognitive load limiting available resources for executing concurrent cognitive tasks. Electroencephalographic activity (EEG: alpha and theta power was obtained in 10 hyperthermic participants in HOT (50°C, 50% RH conditions and in a normothermic state in CON (25°C, 50% RH conditions in counterbalanced order. In each trial, EEG was measured over the frontal lobe prior to task engagement (PRE in each condition and during simple (One Touch Stockings of Cambridge, OTS-4 and complex (OTS-6 cognitive tasks. Core (39.5 ± 0.5 vs. 36.9 ± 0.2°C and mean skin (39.06 ± 0.3 vs. 31.6 ± 0.6°C temperatures were significantly higher in HOT than CON (p < 0.005. Theta power significantly increased with task demand (p = 0.017, η2 = 0.36 and was significantly higher in HOT than CON (p = 0.041, η2 = 0.39. The difference between HOT and CON was large (η2 = 0.40 and significant (p = 0.036 PRE, large (η2 = 0.20 but not significant (p = 0.17 during OTS-4, and disappeared during OTS-6 (p = 0.87, η2 = 0.00. Those changes in theta power suggest that hyperthermia may act as an additional cognitive load. However, this load disappeared during OTS-6 together with an impaired performance, suggesting a potential saturation of the available resources.

  20. Combined treatment of 8 MHz radiofrequency hyperthermia and irradiation for advanced urological malignancies

    International Nuclear Information System (INIS)

    Nakajima, Kazuyoshi; Hisazumi, Haruo; Yamamoto, Hajime; Naito, Katsusuke; Misaki, Toshimitsu; Kobashi, Kazunori; Yokoyama, Osamu; Saito, Yasuo

    1986-01-01

    A combined therapy of irradiation and 8 MHz radiofrequency hyperthermia using Thermotron-RF Model 8 was carried out in a total of 26 patients with urological malignancies; 9 renal cancers, 1 renal capsular tumor, multiple liver metastatic lesions of renal cancer, a postoperative mediastinal metastasis of renal cancer, 2 ureteral cancers associated with bladder cancers, 4 bladder cancers, 4 prostatic cancers, a postoperative local recurrent tumor of an adult type Wilms' tumor, and multiple skin metastatic lesions of a penile cancer. Previous therapies were unsuccessful, or surgical interventions were not indicated because of poor general conditions. They were irradiated with daily 1.8 to 2.0 Gy, 5 times a week, or daily 2.0 to 4.0 Gy twice a week. Hyperthermia was induced twice a week within one hour after each irradiation, in total 10 times for 5 weeks. Intratumoral temperature was kept between 42.0 to 44.0 deg C. Clinical efficacy was evaluated by CT, ultrasound and biochemical data. Partial tumor regression, defined as the regression of 50 % or more, was obtained in one of the 9 renal cancers, in the mediastinal metastasis of renal cancer, 2 of the 4 prostatic cancers, one of the 4 bladder cancers and the 2 ureteral cancers, CR was obtained in the 2 associated bladder cancers. As side effects, a mild skin burns and anorexia were observed in approximately 50 % of the cases. Subcutaneous fat tissue indurations occurred in 6 of the 30 patients, who had 15 mm or more thickness of subdermal fat tissues, after treatment. (author)

  1. Effect of hyperthermia, radiation and adriamycin combinations on tumor vascular function

    International Nuclear Information System (INIS)

    Eddy, H.A.; Chmielewski, G.

    1982-01-01

    Pathophysiologic studies of tumor vascular responses to hyperthermia, radiation or adriamycin given alone or in specific combinations have been made in the cervical carcinoma grown in the transparent cheek pouch chamber of the Syrian hamster. A specially designed chamber containing a compartment for flowing water enabled controlled heating of the tumor and pouch to within 0.2 0 C; the desired temperatures were achieved within one minute. Heating at 42 0 C for 30 minutes was followed, at 1, 5 or 24 hours, by a second heating for 30 minutes at 42 0 C. In addition, the same period of heating was preceded or followed, at 1, 5 or 24 hour intervals, by a single exposure to 2000R or a single intravenous injectionof adriamycin given at a rate of 0.45 mg/100 gm body weight. Of the three modalities, heat appeared to have the greatest acute effect on the tumor vascular system. A single dose of heat produced a rapid but transient constriction followed by a prominent dilation of vessels. Two heating periods given at a 1 hour interval caused persistent stasis in the tumor which progressed to coagulation necrosis. Although heating prior to irradiation or adriamycin, in general, increased the vascular responses to these agents, this sequence gave no tumor control. Radiation or adriamycin given prior to heating had relatively little effect on the vascular response to heating and produced no tumor control except when heat was applied shortly after irradiation. These studies indicate that changes in the microvasculature and perfusion in tumors, in response to hyperthermia alone or combined in specific sequences with radiation, can alter the internal environment of the tumor to produce a greater degree of tumor control than can be attributed to direct cell killing by these agents

  2. Attenuation of muscle damage by preconditioning with muscle hyperthermia 1-day prior to eccentric exercise.

    Science.gov (United States)

    Nosaka, K; Muthalib, M; Lavender, A; Laursen, P B

    2007-01-01

    This study investigated the hypothesis that muscle damage would be attenuated in muscles subjected to passive hyperthermia 1 day prior to exercise. Fifteen male students performed 24 maximal eccentric actions of the elbow flexors with one arm; the opposite arm performed the same exercise 2-4 weeks later. The elbow flexors of one arm received a microwave diathermy treatment that increased muscle temperature to over 40 degrees C, 16-20 h prior to the exercise. The contralateral arm acted as an untreated control. Maximal voluntary isometric contraction strength (MVC), range of motion (ROM), upper arm circumference, muscle soreness, plasma creatine kinase activity and myoglobin concentration were measured 1 day prior to exercise, immediately before and after exercise, and daily for 4 days following exercise. Changes in the criterion measures were compared between conditions (treatment vs. control) using a two-way repeated measures ANOVA with a significance level of P < 0.05. All measures changed significantly following exercise, but the treatment arm showed a significantly faster recovery of MVC, a smaller change in ROM, and less muscle soreness compared with the control arm. However, the protective effect conferred by the diathermy treatment was significantly less effective compared with that seen in the second bout performed 4-6 weeks after the initial bout by a subgroup of the subjects (n = 11) using the control arm. These results suggest that passive hyperthermia treatment 1 day prior to eccentric exercise-induced muscle damage has a prophylactic effect, but the effect is not as strong as the repeated bout effect.

  3. Eye and Ear Temperature using Infrared Thermography are Related to Rectal Temperature in Dogs at Rest or With Exercise

    Directory of Open Access Journals (Sweden)

    Brian Michael Zanghi

    2016-12-01

    Full Text Available Rectal body temperature (BT has been documented in exercising dogs to monitor thermoregulation, heat stress risk, and performance during physical activity. Eye (BTeye and ear (BTear temperature measured with infrared thermography (IRT were compared to rectal (BTrec temperature as the reference method and assess alternative sites to track hyperthermia, possibly to establish BTeye IRT as a passive and non-contact method. BT measures were recorded at 09:00, 11:30, 12:30, and 02:30 from Labrador Retrievers (N=16 and Beagles (N=16 while sedentary and with 30-min play-exercise (pre- and 0, 15, 30-min post-exercise. Total exercise locomotor activity counts were recorded to compare relative intensity of play-exercise between breeds. BTrec, BTeye, and BTear were measured within 5 min of the target time. Each BT method was analyzed by ANOVA for main effects of breed and time. Method differences were compared using Bland-Altman plots and linear regression. Sedentary BT differed by breed for BTrec (p<0.0001, BTear (p<0.0001, and BTeye (p=0.06 with Labs having on average 0.3-0.8oC higher BT compared to Beagles. Readings also declined over time for BTeye (p<0.0001 and BTear (p<0.0001, but not for BTrec (p=0.63 for both breeds. Total exercise (30-min activity counts did not differ (p=0.53 between breeds. Time and breed interaction was significant in response to exercise for both BTrec and BTear (p=0.035 and p=0.005, respectively, with a marginal interaction (p=0.09 for BTeye. All 3 methods detected hyperthermia with Labs having a higher increase compared to Beagles. Both BTear and BTeye were significantly (p<0.0001 related to BTrec in all dogs with sedentary or exercise activity. The relationship between BTeye and BTrec improved when monitoring exercise hyperthermia (r=0.674 versus measures at rest (r=0.381, whereas BTear was significantly related to BTrec regardless of activity (r=0.615-0.735. Although BT readings were significantly related, method bias (p<0

  4. Estimation of complete temperature fields from measured temperatures

    International Nuclear Information System (INIS)

    Clegg, S.T.; Roemer, R.B.

    1984-01-01

    In hyperthermia treatments, it is desirable to be able to predict complete tissue temperature fields from sampled temperatures taken at a few locations. This is a difficult problem in hyperthermia treatments since the tissue blood perfusion is unknown. An initial attempt to do this automatically using unconstrained optimization techniques to minimize the differences between steady state temperatures measured during a treatment and temperatures (at the same locations) predicted from treatment simulations has been previously reported. A second technique using transient temperatures following a step decrease in power has been developed. This technique, which appears to be able to better predict complete temperature fields is presented and both it and the steady state technique are applied to data from both simulated and experimental hyperthermia treatments. The results of applying the two techniques are compared for one-dimensional situations. One particularly important problem which the transient technique can solve (and the steady state technique does not seem to be able to do as well) is that of predicting the complete temperature field in situations where the true maximum and/or minimum temperatures present are not measured by the available instrumentation

  5. Radiotherapy and local hyperthermia plus androgen suppression in locally advanced prostate cancer

    International Nuclear Information System (INIS)

    Maluta, S.; Marciai, N.; Gabbani, M.; Palazzi, M.; Dall'Oglio, S.; Grandinetti, A.

    2005-01-01

    Full text: In advanced prostatic cancer, hyperthermia may be useful in order to enhance irradiation efficacy so to avoid delivering of too high dose of radiotherapy which increases acute and late sequelae. A multi-centric phase II study is warranted to give hyperthermia a level 3 evidence in prostate cancer treatment. A randomized phase III study to demonstrate efficacy of hyperthermia is not available because of the optimal results obtained by using radiotherapy combined with androgen suppression. To evaluate hyperthermia gain, LHT should be combined with radiotherapy alone in patients refusing androgen suppression or affected by hormone refractory prostate carcinoma (HRPC). Patients with HRPC have multiple possibilities of treatment improving performance status and median survival, as chemotherapy regimens, and new agents. All these treatments modalities need to be confirmed by phase III trials. Also hyperthermia may be considered among these promising approaches. (author)

  6. Magnetic Hyperthermia and Radiation Therapy: Radiobiological Principles and Current Practice †

    Directory of Open Access Journals (Sweden)

    Spiridon V. Spirou

    2018-06-01

    Full Text Available Hyperthermia, though by itself generally non-curative for cancer, can significantly increase the efficacy of radiation therapy, as demonstrated by in vitro, in vivo, and clinical results. Its limited use in the clinic is mainly due to various practical implementation difficulties, the most important being how to adequately heat the tumor, especially deep-seated ones. In this work, we first review the effects of hyperthermia on tissue, the limitations of radiation therapy and the radiobiological rationale for combining the two treatment modalities. Subsequently, we review the theory and evidence for magnetic hyperthermia that is based on magnetic nanoparticles, its advantages compared with other methods of hyperthermia, and how it can be used to overcome the problems associated with traditional techniques of hyperthermia.

  7. Thermal wave propagation in blood perfused tissues under hyperthermia treatment for unique oscillatory heat flux at skin surface and appropriate initial condition

    Science.gov (United States)

    Dutta, Jaideep; Kundu, Balaram

    2018-05-01

    This paper aims to develop an analytical study of heat propagation in biological tissues for constant and variable heat flux at the skin surface correlated with Hyperthermia treatment. In the present research work we have attempted to impose two unique kind of oscillating boundary condition relevant to practical aspect of the biomedical engineering while the initial condition is constructed as spatially dependent according to a real life situation. We have implemented Laplace's Transform method (LTM) and Green Function (GFs) method to solve single phase lag (SPL) thermal wave model of bioheat equation (TWMBHE). This research work strongly focuses upon the non-invasive therapy by employing oscillating heat flux. The heat flux at the skin surface is considered as constant, sinusoidal, and cosine forms. A comparative study of the impact of different kinds of heat flux on the temperature field in living tissue explored that sinusoidal heat flux will be more effective if the time of therapeutic heating is high. Cosine heating is also applicable in Hyperthermia treatment due to its precision in thermal waveform. The result also emphasizes that accurate observation must be required for the selection of phase angle and frequency of oscillating heat flux. By possible comparison with the published experimental research work and published mathematical study we have experienced a difference in temperature distribution as 5.33% and 4.73%, respectively. A parametric analysis has been devoted to suggest an appropriate procedure of the selection of important design variables in viewpoint of an effective heating in hyperthermia treatment.

  8. The response on glucoregulatory hormones of in vivo whole body hyperthermia.

    Science.gov (United States)

    Kappel, M; Gyhrs, A; Galbo, H; Pedersen, B K

    1997-01-01

    This study was designed to examine the effects of in vivo hyperthermia on the circulating concentrations of a number of glucoregulatory hormones potentially involved in immunomodulation. Eight healthy male volunteers were immersed for 2 h in a hot water bath (water temperature 39.5 degrees C) (WI) during which period their rectal temperature rose to 39.5 degrees C. In a control study the subjects were immersed in thermoneutral water (water temperature 34.5 degrees C). Blood samples were collected before, at body temperature 38 degrees C (42.5 (30-52), median and range), minutes of hot WI, 39 degrees C (72.5 (58-97) minutes of hot WI), and 39.5 degrees C (at the end of 2 h of hot WI), as well as 1 and 2 h after cessation of 2 h of hot WI. In the control experiment blood samples were collected at identical time points. The growth hormone concentrations were elevated already at 38 degrees C to 24.2 (3.9-55.0) mU/l and peaked at 39 degrees C to 48.4 (20.8-81.5) mU/l compared to 0.3 (0.3-9.0) mU/l at baseline; at 39.5 degrees C the concentration declined to 31.6 (13.0-48.0) mU/l and further to 7.4 (0.8-17.3) mU/l 1 h after ending hot WI. The beta-endorphin levels were augmented at 39 degrees C and 39.5 degrees, to 8.0 (3.4-27.8) pmol/l and 8.1 (3.1-44.6) pmol/l, respectively, from 2.2 (0.7-5.6) pmol/l baseline. Glucagon levels raised from 23.0 (12.0-32.0) pmol/l to 32.0 (24.0-52.0) pmol/l at 39 degrees C, and to 38.5 (26.0-57.0) pmol/l at 39.0 degrees C. Insulin levels remained unchanged. Plasma glucose increased from 4.75 (4.2-7.6) mmol/l to 5.20 (4.6-5.6) mmol/l alone after 90 min of WI (temperature 39-39.5 degrees C). It is concluded that in vivo whole body WI hyperthermia increases the circulating levels of several essential glucoregulatory hormones.

  9. Role of vascular physiology in hyperthermia

    International Nuclear Information System (INIS)

    Song, C.W.

    1987-01-01

    The rate of blood supply to tumors significantly varies depending on the tumor type, site of tumor growth, and the stage of tumor growth. Even in the same tumor, blood flow is rather heterogeneous. The peripheral area of the tumors where the tissue pressure is relatively low is usually well perfused. Blood flow in the tumors may or may not be greater than that in the adjacent normal tissues. The response of newly formed tumor blood vessels to external stress, such as heat, it different from that in the normal tissues. Blood flow in the experimental rodent tumors initially increases up to twofold of control when heated at relatively low temperatures but tends to decrease when heated at temperatures above 42 0 -43 0 C. On the contrary, blood flow in the skin and muscle of rodents increases up to 20-fold before vascular damage occurs on heating at 43 0 -45 0 C. It thus appears that the vascular beds in tumors are more vulnerable to heat than those in normal tissues. Because of the large increase in blood flow in normal tissue on heating, heat dissipation by blood flow is usually greater in normal tissues than that in tumors during heating. Consequently, the temperature of tumors may rise higher than that in normal tissues. Preferential heating of tumors, however, may not be achieved all the time because the relative blood perfusion in some tumors or in parts of a tumor remains greater than that in the surrounding normal tissues. The intrinsically acidic intratumor environment becomes further acidic on heating owing to an increase in the synthesis of acidic metabolites and retarded removal of them as a result of heat-induced vascular damage. The intratumor environment also becomes hypoxic as a result of retardation of blood flow and vascular damage after heating

  10. Effects of γ radiation and hyperthermia on DNA repair synthesis and the level of NAD+ in cultured human mononuclear leukocytes

    International Nuclear Information System (INIS)

    Jonsson, G.G.; Eriksson, G.; Pero, R.W.

    1984-01-01

    DNA repair has been investigated, estimated by unscheduled DNA synthesis (UDS) and the cellular NAD + pool, after exposing human mononuclear leukocytes to hyperthermia and γ radiation separately and in combination. It was found that γ radiation induced a decline in UDS with increasing temperature through the temperature region studied (37-45 0 C). At 42.5 0 C the γ-ray-induced UDS was reduced to about 70% of that at 37 0 C. Following γ-ray damage the NAD + pool dropped to about 20% of control values. Without hyperthermic treatment the cells completely recovered to the original level within 5 hr. Moderate hyperthermia (42.5 0 C for 45 min) followed by γ-ray damage altered the kinetics so that even after 8 hr the NAD + pool had recovered to only 70% of the original level. After heat treatment at 44 0 C for 45 min prior to γ radiation the cells did not recover at all, presumably because of the cytotoxic effects from the combined treatment

  11. Different effectiveness of hyperthermia with regard to fast electrons and X-rays with different energy spectra

    International Nuclear Information System (INIS)

    Schrader-Reichhardt, U.; Markus, B.

    1981-01-01

    The synergistic enhancement of the irradiation effect by mild (40.5 0 C) and strong (43 0 C) hyperthermia (TER = temperature enhancement ratio) was examined for different sparsely ionizing radiation qualities (15 MeV electrons in two irradiation depths corresponding to a relative depth dose of 100% and 30%, 200-kV and 29-kV-X-rays). Hypotetraploid ( 4n ) and diploid (2n), asynchronous, exponentially growing CHO fibroblasts were used as experimental subjects. The survival in the colony test was used as criterion to assess the effect. The experiments carried out with 4n cells showed that, for the two temperatures, the TER decreases with increasing ionization density and, when applying fast electrons producing an extremely sparse ionization in an irradiation depth of 100%, the TER shows a maximum increase as compared to the more densely ionizing radiation qualities. Already when mild hyperthermia is employed, fast electrons show a TER of 1.25 which rises to about 2.25 at 43 0 C. In case of 29-kV-X-rays, these values amount to 1 and 1.66 respectively. As to the 2n cells, the TER reaches here the double value and seems to be similarly dependent on the ionization density. (orig.) [de

  12. Modeling skin cooling using optical windows and cryogens during laser induced hyperthermia in a multilayer vascularized tissue

    International Nuclear Information System (INIS)

    Singh, Rupesh; Das, Koushik; Okajima, Junnosuke; Maruyama, Shigenao; Mishra, Subhash C.

    2015-01-01

    This article deals with the spatial and the temporal evolution of tissue temperature during skin surface cooled laser induced hyperthermia. Three different skin surface cooling methodologies viz., optical window contact cooling, cryogenic spray cooling and cryogen cooled optical window contact cooling are considered. Sapphire, yttrium aluminum garnet, lithium tantalate, and magnesium oxide doped lithium niobate are the considered optical windows. The cryogens considered are liquid CO_2 and R1234yf. Heat transfer in the multilayer skin tissue embedded with thermally significant blood vessels pairs is modeled using the Pennes and Weinbaum–Jiji bioheat equations. Weinbaum–Jiji bioheat equation is used for the vascularized tissue. Laser transport in the tissue is modeled using the radiative transfer equation. Axial and radial (skin surface) temperature distributions for different combinations of optical windows and cryogens are analyzed. Liquid CO_2 cooled yttrium aluminum garnet is found to be the best surface cooling mechanism. - Highlights: • Skin surface cooled laser induced hyperthermia is studied. • A multi-layer 2-D cylindrical tissue geometry is considered. • Both Pennes and Weinbaum–Jiji bioheat models are considered. • Laser transport in the tissue is modeled using discrete ordinate method. • Results for 4 optical windows and 2 cryogens for skin cooling are presented.

  13. Silica-modified Fe-doped calcium sulfide nanoparticles for in vitro and in vivo cancer hyperthermia

    International Nuclear Information System (INIS)

    Wu, Steven Yueh-Hsiu; Yang, Kai-Chiang; Tseng, Ching-Li; Chen, Jung-Chih; Lin, Feng-Huei

    2011-01-01

    In this study, sulfide-based magnetic Fe-doped CaS nanoparticles modified with a silica layer were investigated for cancer hyperthermia. A polyvinyl pyrrolidone polymer was used as the coupling agent. The developed nanoparticles contained 11.6 wt% iron concentration, and their X-ray diffraction pattern was similar to those of CaS and Fe–CaS nanoparticles. The average particle size was approximately 47.5 nm and homogeneously dispersed in aqueous solutions. The major absorption bands of silica were observed from the FTIR spectrum. The magnetic properties and heating efficiency were also examined. The specific absorption ratio of nanoparticles at a concentration of 10 mg/mL at 37 °C in an ethanol carrier fluid was 37.92 W/g, and the nanoparticles would raise the temperature to over 45 °C within 15 min. A cytotoxicity analysis revealed that the nanoparticles had good biocompatibility, which indicated that the nanoparticles did not affect cell viability. The therapeutic effects of the nanoparticles were investigated using in vitro and animal studies. Cells seeded with nanoparticles and treated under an AC magnetic field revealed a percentage of cytotoxicity (60%) that was significantly higher from that in other groups. In the animal study, during a hyperthermia period of 15 days, tumor-bearing Balb/c mice that were subcutaneously injected with nanoparticles and exposed to an AC magnetic field manifested a reduction in tumor volume. The newly developed silica-modified Fe–CaS nanoparticles can thus be considered a promising and attractive hyperthermia thermoseed.

  14. Exchange-coupled Fe3O4/CoFe2O4 nanoparticles for advanced magnetic hyperthermia

    Science.gov (United States)

    Glassell, M.; Robles, J.; Das, R.; Phan, M. H.; Srikanth, H.

    Iron oxide nanoparticles especially Fe3O4, γ-Fe2O3 have been extensively studied for magnetic hyperthermia because of their tunable magnetic properties and stable suspension in superparamagnetic regime. However, their relatively low heating capacity hindered practical application. Recently, a large improvement in heating efficiency has been reported in exchange-coupled nanoparticles with exchange coupling between soft and hard magnetic phases. Here, we systematically studied the effect of core and shell size on the heating efficiency of the Fe3O4/CoFe2O4 core/shell nanoparticles. The nanoparticles were synthesized using thermal decomposition of organometallic precursors. Transmission electron microscopy (TEM) showed formation of spherical shaped Fe3O4 and Fe3O-/CoFe2O4 nanoparticles. Magnetic measurements showed high magnetization (≅70 emu/g) and superparamagnetic behavior for the nanoparticles at room temperature. Magnetic hyperthermia results showed a large increase in specific absorption rate (SAR) for 8nm Fe3O4/CoFe2O4 compared to Fe3O4 nanoparticles of the same size. The heating efficiency of the Fe3O4/CoFe2O4 with 1 nm CoFe2O4 (shell) increased from 207 to 220 W/g (for 800 Oe) with increase in core size from 6 to 8 nm. The heating efficiency of the Fe3O4/CoFe2O4 with 2 nm CoFe2O4 (shell) and core size of 8 nm increased from 220 to 460 W/g (for 800 Oe). These exchange-coupled Fe3O4/CoFe2O4 core/shell nanoparticles can be a good candidate for advanced hyperthermia application.

  15. Multimodal treatment combining chemotherapy, hyperthermia and radiotherapy for ovarian cancer

    International Nuclear Information System (INIS)

    Nagashima, Kei

    1992-01-01

    There has been increasing interest in the use of heat in the treatment of cancer. Theoretically cells are the most sensitive to ionizing radiation at mitosis, whereas the cycle phase that is the most resistant to ionizing radiation namely late in the DNA. Synthetic phase (late S) is the most sensitive to hyperthermia. Hyperthermia has been reported to enhance the cytocidal effects of several active chemotherapeutic agents. When thermal potentiation of chemotherapeutic agents against malignant cells is contemplated, normal tissues have a relatively high ambient blood flow which increases in response to thermal stress, thereby dissipating heat, compared to tumors. Tumors, with relatively poor blood flow and a responsive neovasculature, are in capable of augmenting flow and acting as a heat reservoir. This is the phenomenon of a heat reservoir which is one factor to enhance the cytocidal effects of several active anticancer agents for enhancing the uptake in tumor. The importance is in the adjuvant chemotherapy treated for post operative, advanced and recurrent ovarian cancer. Heating enhances the effects of radiotherapy and chemotherapy. Thirty patients with ovarian cancer were subjected to the multidisciplinary treatment with combination of hyperthermochemotherapy and radiation. The 30 patients consisted of 18 with endometrioid adenocarcinoma and 7 with serious post operative or recurrent status. Two types of equipments with rediofrequencies of 70 MHz (BSD-1000) or 434 MHZ (TAG MED·HS 434) were used for hyperthermia. Chemotherapeutic agents such as adriamycin, cis DDP, cyclophosphamide and etoposide were injected intravenously. Arterial infusion with reservoir was very effective in advanced stage of ovarian cancer. No severe or fatal side effects were observed. Hyperthermochemotherapy is useful and effective for the postoperative management or the treatment of recurrent cancer of the ovary. (J.P.N.)

  16. Stereotactic technique of RF antenna implantation for brain hyperthermia

    International Nuclear Information System (INIS)

    Takahashi, H.; Uzuka, T.; Grinev, I.; Tanaka, R.

    2005-01-01

    Full text: We have tried 13.56 MHz RF interstitial hyperthermia for the patients with malignant brain tumor. The purpose of this report is to assess the complication risk rate and the achievement yield of stereotactic procedure for RF antenna implantation into the deep-seated brain tumor. One hundred and twenty-five patients underwent 144 stereotactic RF antenna implantation procedures for interstitial hyperthermia for malignant brain tumors at Niigata University, Japan. One hundred and eight patients had malignant gliomas (54 primary, 54 recurrent), 24 had metastatic tumors, 5 had malignant lymphomas, 5 had meningiomas and 2 had miscellaneous tumors. Indication of this trial was the tumor with inoperative deep-seated tumor or elderly patients. RF antennas and catheters for thermistor probes were set into the tumor with stereotactic apparatus under local anesthesia. Postoperative CT scan underwent in order to assess the accuracy of antenna setting and to check the complications. The hyperthermic treatment underwent with a single antenna in 85 patients, 2 antennas in 43 patients, 3 in 2, 4 in 12, 5 in 1 and 6 antennas in 1 patient. Appropriate RF antenna positioning was obtained in 138 of 144 procedures (95.8 %). Six patients incurred complications (4.2 %). Three patients suffered intratumoral hemorrhage. RF antennas were set into the inappropriate position in 2 cases, hyperthermia was not achieved. One patient occurred with liquorrhea. However, six patients (4.2 %) incurred complications, stereotactic RF antenna setting was a safe and reliable technique of the hyperthermic treatment for the patients with malignant brain tumors. (author)

  17. Hyperthermia on skin immune system and its application in the treatment of HPV-infected skin diseases

    Institute of Scientific and Technical Information of China (English)

    Gao Xinghua; Chen Hongduo

    2014-01-01

    In this paper, the effects of hyperthermia on cells and immune system are introduced briefly. The mechanism of action of hyperthermia on human papilloma virus (HPV)-infected skin diseases was elaborated as an example in this paper. Many studies have proved that hyperthermia affects a number of cellular and molecu- lar constitutes in the skin immune system, involving both innate and adaptive immune responses; the efficacy of hyperthermia in treating some infectious and cancerous conditions has been validated and applied in clinics, while molecular mechanisms of hyperthermia affecting the immunereaction is still unclear.

  18. An ultrasonic phased array applicator for deep localized hyperthermia

    International Nuclear Information System (INIS)

    Ocheltree, K.B.; Benkeser, P.J.; Foster, S.G.; Frizzell, L.A.; Cain, C.A.

    1984-01-01

    The use of an ultrasonic phased array applicator presents a major advantage over the fixed beam ultrasonic applicators which are typically used for clinical hyperthermia. Such an applicator allows focal region placement in the three dimensional treatment field by electronic steering instead of mechanical movement of the transducer assembly. The design of an array is discussed theoretically, considering that the constraints on grating lobes and power output for hyperthermic applications are quite different from those for imaging. The effects of various design parameters are discussed. Experimental results are presented for several arrays for frequencies under 1 Mhz

  19. Boron-doped nanodiamonds as possible agents for local hyperthermia

    Science.gov (United States)

    Vervald, A. M.; Burikov, S. A.; Vlasov, I. I.; Ekimov, E. A.; Shenderova, O. A.; Dolenko, T. A.

    2017-04-01

    In this work, the effective heating of surrounding water by heavily-boron-doped nanodiamonds (NDs) under laser irradiation of visible wavelength was found. Using Raman scattering spectroscopy of aqueous suspensions of boron-doped NDs, it was found that this abnormally high heating results in the weakening of hydrogen bonds much more so (2-5 times stronger) than for undoped NDs. The property of boron-doped NDs to heat a solvent under the influence of laser radiation (1-5 W cm-2) opens broad prospects for their use to create nanoagents for medical oncology and local hyperthermia.

  20. Malignant Hyperthermia in Dental and Facial Plastic surgeries

    Directory of Open Access Journals (Sweden)

    Ramin Maheri

    2015-04-01

    Full Text Available Preoperative evaluation of the patients scheduled for ambulatory surgery is of great importance in regards of both surgery and anesthesia considerations. Malignant Hyperthermia (MH is a pharmacogenetic clinical syndrome which mostly arises from volatile anesthesia with halothane and the depolarizing muscle relaxant succinylcholine. Clinical manifestations of MH are acidosis and rhabdomyolysis which occur following uncontrolled increases in skeletal muscle metabolism and rapidly increasing body temperature (by as much as 1°C/5 min (1. Primary cases of MH were reported to be of a 70% mortality rate; however, thanks to the emergence of diagnostic tools such as end-expired carbon dioxide and the administration of dantrolene, this rate has decreased to less than 5%.      MH might occur even in those with no previous or familial history. Even a safe history of the previous surgery under the administration of MH triggering agents cannot guarantee a next safe surgery. A noteworthy point in the preoperative evaluation is the probable association of MH with certain musculoskeletal disorders including Duchenne, Becker, and myotonic muscular dystrophies, strabismus, osteogenesis imperfecta, ptosis, myelomeningocele, kyphoscoliosis, King-Denborough syndrome, periodic paralysis, hernias, marfanoid syndrome, and central core disease (1. These diseases are frequently encountered by dental and facial plastic surgeons and having the knowledge of the probable association between MH and these conditions could aware the dental and facial plastic surgeons and the anesthesiologists to be more vigilant.      Although MH workup leads to the definite diagnosis, no convincing intraoperative diagnostic tool has been introduced so far. Masseter spasm is a condition which might follow administration of depolarizing neuromuscular blocking agents due to the slow tonic fibers of masseter and lateral pterygoid muscles (2-4. The severer forms of masseter spasm would

  1. A comparison of fisheries biological reference points estimated from temperature-specific multi-species and single-species climate-enhanced stock assessment models

    Science.gov (United States)

    Holsman, Kirstin K.; Ianelli, James; Aydin, Kerim; Punt, André E.; Moffitt, Elizabeth A.

    2016-12-01

    Multi-species statistical catch at age models (MSCAA) can quantify interacting effects of climate and fisheries harvest on species populations, and evaluate management trade-offs for fisheries that target several species in a food web. We modified an existing MSCAA model to include temperature-specific growth and predation rates and applied the modified model to three fish species, walleye pollock (Gadus chalcogrammus), Pacific cod (Gadus macrocephalus) and arrowtooth flounder (Atheresthes stomias), from the eastern Bering Sea (USA). We fit the model to data from 1979 through 2012, with and without trophic interactions and temperature effects, and use projections to derive single- and multi-species biological reference points (BRP and MBRP, respectively) for fisheries management. The multi-species model achieved a higher over-all goodness of fit to the data (i.e. lower negative log-likelihood) for pollock and Pacific cod. Variability from water temperature typically resulted in 5-15% changes in spawning, survey, and total biomasses, but did not strongly impact recruitment estimates or mortality. Despite this, inclusion of temperature in projections did have a strong effect on BRPs, including recommended yield, which were higher in single-species models for Pacific cod and arrowtooth flounder that included temperature compared to the same models without temperature effects. While the temperature-driven multi-species model resulted in higher yield MBPRs for arrowtooth flounder than the same model without temperature, we did not observe the same patterns in multi-species models for pollock and Pacific cod, where variability between harvest scenarios and predation greatly exceeded temperature-driven variability in yield MBRPs. Annual predation on juvenile pollock (primarily cannibalism) in the multi-species model was 2-5 times the annual harvest of adult fish in the system, thus predation represents a strong control on population dynamics that exceeds temperature

  2. Targeted hyperthermia after selective embolization with ferromagnetic nanoparticles in a VX2 rabbit liver tumor model

    Directory of Open Access Journals (Sweden)

    Sun HL

    2013-10-01

    Full Text Available Hongliang Sun,1 Linfeng Xu,1 Tianyuan Fan,2 Hongzhi Zhan,3 Xiaodong Wang,3 Yanfei Zhou,2 Ren-jie Yang3 1Department of Interventional Therapy, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University, Guangzhou, 2Pharmacy School of Beijing University, Beijing, 3Department of Interventional Therapy, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing, People's Republic of China Background: The purpose of this study was to observe the effect and feasibility of hyperthermia and the influence of heat on surrounding organs in a VX2 rabbit liver model exposed to an alternating magnetic field after embolization with ferromagnetic nanoparticles. Methods: Forty rabbits containing implanted hepatic VX2 carcinomas were divided into four groups, each containing ten rabbits. Fourteen days after tumor transplantation, we opened the abdomen to observe the size and shape of the tumor. A transfemoral retrograde approach was then used for hepatic arterial catheterization in groups B, C, and D to perform angiography and embolization. The next day, three rabbits in group B and all rabbits in group D were exposed to an alternating magnetic field, and the temperature was recorded simultaneously in the center of the tumor, at the edge of the tumor, and in the normal liver parenchyma. On day 28, all animals was euthanized to observe changes in the implanted liver tumor and the condition of the abdomen. A pathologic examination was also done. Results: Before surgery, there was no significant difference in tumor volume between the four groups. Three different temperature points (center of the tumor, edge of the tumor, and in the normal liver parenchyma of group B under an alternating magnetic field were 37.2°C ± 1.1°C, 36.8°C ± 1.2°C, and 36.9°C ± 2.1°C, none of which were significantly different from pretreatment values. Three points basal temperature in group D showed no significant difference (F = 1.038, P = 0.413. Seven to 26

  3. Developing a theoretical predictive model for cellular response to combined actions of low radiation and hyperthermia

    International Nuclear Information System (INIS)

    Jin Kyu Kim; Petin, V.G.; Mishra, K.P.

    2007-01-01

    Complete text of publication follows. Background: Organisms in their living environment are not exposed to merely a single stress agent. Several factors such as radiation and heat may simultaneously exert their stressful effect to the organisms. The combined exposure to two stressors can result in an enhanced effect that would be expected from the addition of the separate exposures to individual agents. Objective: This study has been undertaken to develop a theoretical model for assessment of combined effects of low dose radiation and mild heat for predictive cellular response assay. Rationale: Present study was motivated from the belief that synergism may occur in terms of lethal lesions arising from the interaction of non-lethal sub-lesions induced by individual agents. The sub-lesions induced by each agent may be negligible or undetectable. But, there exists a possibility of some cross talk between sublesions produced by radiation and heat. These processes may reflect the real mechanisms for inflicting the lethal damage by otherwise ignorable or undetectable insults to exposed organisms. Results: A theoretically developed mathematical model of the synergy was formulated which was tested for validation on the experimental data. The model predictions fairly closely corresponded with several experimental results. .The significance of synergistic effects for radiation biology has been demonstrated. A number of common peculiarities of synergistic interactions were found to play their roles. A unified biophysical concept for synergistic interaction has been suggested. Conclusions: For a constant dose rate, synergistic interaction between radiation and hyperthermia especially at low intensity is realized only within a certain range of temperature, independently of the target object analyzed. For temperatures below the range, the synergistic effect was not observed and cell killing was mainly determined by the damage induced by ionizing radiation. On the contrary, the

  4. FEVER AS KEY SYMPTOM OF ACUTE RESPIRATORY INFECTIONS AND MODERN METHODS OF THERAPY FOR HIGH TEMPERATURE IN CHILDREN

    Directory of Open Access Journals (Sweden)

    O.A. Solntseva

    2010-01-01

    Full Text Available Hyperthermia is the key symptom of acute respiratory infections (ARI. An increase in the body temperature is accompanied with phagocytosis activation, increased interferon synthesis, antibody genesis stimulation, lymphocytes activation and differentiation. Nevertheless, significant hyperthermia may result in my unfavourable consequences. It may particularly cause an exacerbation of chronic diseases. Modern therapy for hyperthermia is, therefore, an important aspect of treating children with ARI. The article outlines the modern approach to treating fever in children, identifies key criteria for selecting a medication. It also contains a case study of applying ibuprofen and data from various trials which verify the rationale for applying ibuprofen in children with hyperthermia that developed in conjunction with ARI.Key words: children, acute respiratory infections, hyperthermia, ibuprofen.(Voprosy sovremennoi pediatrii — Current Pediatrics. 2010;9(5:80-84

  5. Neurological basis of AMP-dependent thermoregulation and its relevance to central and peripheral hyperthermia

    Science.gov (United States)

    Muzzi, Mirko; Blasi, Francesco; Masi, Alessio; Coppi, Elisabetta; Traini, Chiara; Felici, Roberta; Pittelli, Maria; Cavone, Leonardo; Pugliese, Anna Maria; Moroni, Flavio; Chiarugi, Alberto

    2013-01-01

    Therapeutic hypothermia is of relevance to treatment of increased body temperature and brain injury, but drugs inducing selective, rapid, and safe cooling in humans are not available. Here, we show that injections of adenosine 5′-monophosphate (AMP), an endogenous nucleotide, promptly triggers hypothermia in mice by directly activating adenosine A1 receptors (A1R) within the preoptic area (POA) of the hypothalamus. Inhibition of constitutive degradation of brain extracellular AMP by targeting ecto 5′-nucleotidase, also suffices to prompt hypothermia in rodents. Accordingly, sensitivity of mice and rats to the hypothermic effect of AMP is inversely related to their hypothalamic 5′-nucleotidase activity. Single-cell electrophysiological recording indicates that AMP reduces spontaneous firing activity of temperature-insensitive neurons of the mouse POA, thereby retuning the hypothalamic thermoregulatory set point towards lower temperatures. Adenosine 5′-monophosphate also suppresses prostaglandin E2-induced fever in mice, having no effects on peripheral hyperthermia triggered by dioxymetamphetamine (ecstasy) overdose. Together, data disclose the role of AMP, 5′-nucleotidase, and A1R in hypothalamic thermoregulation, as well and their therapeutic relevance to treatment of febrile illness. PMID:23093068

  6. Thermal dosimetry studies of ultrasonically induced hyperthermia in normal dog brain and in experimental brain tumors

    International Nuclear Information System (INIS)

    Britt, R.H.; Pounds, D.W.; Stuart, J.S.; Lyons, B.E.; Saxer, E.L.

    1984-01-01

    In a series of 16 acute experiments on pentobarbital anesthetized dogs, thermal distributions generated by ultrasonic heating using a 1 MHz PZT transducer were compared with intensity distributions mapped in a test tank. Relatively flat distributions from 1 to 3 cm have been mapped in normal dog brain using ''shaped'' intensity distributions generated from ultrasonic emission patterns which are formed by the interaction between compressional, transverse and flexural modes activated within the crystal. In contrast, these same intensity distributions generated marked temperature variations in 3 malignant brain tumors presumably due to variations in tumor blood flow. The results of this study suggest that a practical clinical system for uniform heating of large tumor volumes with varying volumes and geometries is not an achievable goal. The author's laboratory is developing a scanning ultrasonic rapid hyperthermia treatment system which will be able to sequentially heat small volume of tumor tissue either to temperatures which will sterilize tumor or to a more conventional thermal dose. Time-temperature studies of threshold for thermal damage in normal dog brain are currently in progress

  7. Local superficial hyperthermia in combination with low-dose radiation therapy for palliation of superficially localized metastases

    International Nuclear Information System (INIS)

    Owczarek, G.; Miszczyk, L.

    2005-01-01

    Full text: The aim of this study is to evaluate the response of superficially located metastases and local toxicity to microwave hyperthermia combined with radiation therapy. From May 2003 through December 2004 58 patients (33 male, 25 female; mean age 60 years) with lymph nodes or skin metastases were treated with microwave superficial hyperthermia combined with low-dose radiation therapy. Hyperthermia was administered twice weekly with high frequency applicator (∼900 Mhz) with water bolus. The temperature was set to 43 o C for 45 minutes. Radiotherapy was performed daily with dose 2 Gy or 4 Gy per fraction, to a total dose 20 Gy. There were 47 patients with carcinoma, 4 with sarcoma, 7 with melanoma. Treated regions were: head and neck (37 patients), chest wall 8, abdomen wall and groins 4, upper and lower limb 2 and 8 patients respectively. Primary tumor sites were: head and neck region (9 patients), lung 15, alimentary tract 8, breast 5, soft tissue 8, urogenital 4 and 9 patients with primary tumor site unknown. The toxicity was evaluated using 6 step scale: 0-no skin reaction, 1-faint red mark, 2-distinct red mark, 3-blisters, 4-brown mark, 5-necrosis. Presence of pain and its intensity were also analyzed. Diameter of tumor after the treatment was observed. Complete response was achieved in 5 patients (8.5 %), and partial response in 29 patients (50 %), no response was observed in 12 patients (20 %) and progression of tumor in 7 patients (12 %). No skin reaction was observed in 3 patients, faint red mark in 14 patients, distinct red mark in 28 patients, blisters in 8 patients, brown mark in 4 patients and necrosis in 1 patient. The pain occurred in 9 patients but it was no the cause of stopping treatment. Local superficial hyperthermia combined with low-dose radiation therapy is an effective method of treatment in a proportion of patients with superficial metastases. This combination of treatment modalities is well tolerated and is useful for palliation

  8. Implant strategies for endocervical and interstitial ultrasound hyperthermia adjunct to HDR brachytherapy for the treatment of cervical cancer

    International Nuclear Information System (INIS)

    Wootton, Jeffery H; Prakash, Punit; Hsu, I-Chow Joe; Diederich, Chris J

    2011-01-01

    Catheter-based ultrasound devices provide a method to deliver 3D conformable heating integrated with HDR brachytherapy delivery. Theoretical characterization of heating patterns was performed to identify implant strategies for these devices which can best be used to apply hyperthermia to cervical cancer. A constrained optimization-based hyperthermia treatment planning platform was used for the analysis. The proportion of tissue ≥41 deg. C in a hyperthermia treatment volume was maximized with constraints T max ≤ 47 deg. C, T rectum ≤ 41.5 deg. C, and T bladder ≤ 42.5 deg. C. Hyperthermia treatment was modeled for generalized implant configurations and complex configurations from a database of patients (n = 14) treated with HDR brachytherapy. Various combinations of endocervical (360 0 or 2 x 180 0 output; 6 mm OD) and interstitial (180 0 , 270 0 , or 360 0 output; 2.4 mm OD) applicators within catheter locations from brachytherapy implants were modeled, with perfusion constant (1 or 3 kg m -3 s -1 ) or varying with location or temperature. Device positioning, sectoring, active length and aiming were empirically optimized to maximize thermal coverage. Conformable heating of appreciable volumes (>200 cm 3 ) is possible using multiple sectored interstitial and endocervical ultrasound devices. The endocervical device can heat >41 deg. C to 4.6 cm diameter compared to 3.6 cm for the interstitial. Sectored applicators afford tight control of heating that is robust to perfusion changes in most regularly spaced configurations. T 90 in example patient cases was 40.5-42.7 deg. C (1.9-39.6 EM 43deg.C ) at 1 kg m -3 s -1 with 10/14 patients ≥41 deg. C. Guidelines are presented for positioning of implant catheters during the initial surgery, selection of ultrasound applicator configurations, and tailored power schemes for achieving T 90 ≥ 41 deg. C in clinically practical implant configurations. Catheter-based ultrasound devices, when adhering to the guidelines, show

  9. Immunogenicity of ascites tumor cells following in vitro hyperthermia

    International Nuclear Information System (INIS)

    Dickson, J.A.; Jasiewicz, M.L.; Simpson, A.C.

    1982-01-01

    The concept that host immunization may be achieved by heat-induced antigenic modifications of cancer cells and/or the release of immunogenic products by dead or dying tumor cells following in vitro heating was examined. Ehrlich ascites cells were used, inasmuch as it was claimed that in vitro hyperthermia increased the immunogenicity of these cells. Tumor cell populations of different viability were obtained by heating Ehrlich cells at 42.5 degrees, 45 degrees, or 60 degrees C. Viable and nonviable cells were separated by Ficoll-Hypaque density centrifugation; viable nonreplicating cells were obtained by treatment with mitomycin C. Cell populations of different viability after heating were left to die slowly over 3 days at 37 degrees C. Swiss TO mice were then given injections of the treated cells and/or medium. No survival benefit occurred in mice inoculated with any of these different components and then challenged with viable tumor cells. Injection of irradiated cells, however, did produce host immunity. Similarly, D23 rat hepatoma ascites cells produced host immunity after 15,000 rad but not after heating. The claim that in vitro hyperthermia increases the immunogenicity of tumor cells was not confirmed

  10. Hyperthermia-induced alteration of yeast susceptibility to mutation

    International Nuclear Information System (INIS)

    Mitchel, R.E.J.; Morrison, D.P.

    1985-01-01

    Diploid yeast (s. cerevisiae) were examined for alterations in susceptibility to induced mutation following hyperthermia treatment. In cells grown at 23 0 C, a non-lethal heat exposure (38 0 C, 30 min) markedly suppressed mutation induced by a subsequent non-killing dose of MNNG of MNU. Mutation by ENU, 8-MOP + UVA, or γ-rays was not affected. An intermediate level of mutation suppression was observed for mutation by 254nm UV or MMS. Mutation by MNNG was not suppressed by the same heat treatment delivered after the mutagen exposure. In a split dose experiment (two MNNG treatments separated by a heat exposure) no suppression of mutation was observed. Treatment with cycloheximide mimicked the effect of heat treatment. These data suggest that mutation induction by MNNG or MNU is protein synthesis dependent, i.e. an error-prone repair system is induced by exposure to MNNG or MNU but not by ENU, 8-MOP+UVA or γ-irradiation. We propose that hyperthermia treatment, by inducing stress protein synthesis at the expense of normal protein synthesis, precludes induction of this error-prone system. Therefore, in heat treated cells, DNA lesions produced by MNNG or MNU exposure must be resolved by an essentially constitutive system which is less error-prone than the inducible one

  11. A novel hyperthermia treatment for bone metastases using magnetic materials

    International Nuclear Information System (INIS)

    Matsumine, Akihiko; Asanuma, Kunihiro; Matsubara, Takao; Nakamura, Tomoki; Uchida, Atsumasa; Sudo, Akihiro; Takegami, Kenji

    2011-01-01

    Patients with bone metastases in the extremities sometimes require surgical intervention to prevent deterioration of quality of life due to a pathological fracture. The use of localized radiotherapy combined with surgical reinforcement has been a gold standard for the treatment of bone metastases. However, radiotherapy sometimes induces soft tissue damage, including muscle induration and joint contracture. Moreover, cancer cells are not always radiosensitive. Hyperthermia has been studied since the 1940s using an experimental animal model to treat various types of advanced cancer, and studies have now reached the stage of clinical application, especially in conjunction with radiotherapy or chemotherapy. Nevertheless, bone metastases have several special properties which discourage oncologists from developing hyperthermic therapeutic strategies. First, the bone is located deep in the body, and has low thermal conductivity due to the thickness of cortical bone and the highly vascularized medulla. To address these issues, we developed new hyperthermic strategies which generate heat using magnetic materials under an alternating electromagnetic field, and started clinical application of this treatment modality. The purpose of this review is to summarize the latest studies on hyperthermic treatment in the field of musculoskeletal tumors, and to introduce the treatment strategy employing our novel hyperthermia approach. (author)

  12. [Anesthesia unrelated triggering of a fatal malignant hyperthermia crisis].

    Science.gov (United States)

    Olthoff, D; Vonderlind, C

    1997-12-01

    For incidents of malignant hyperthermia (MH) outside the hospital, a high number of unrecorded cases must be reckoned with because of an insufficient knowledge of emergency services and poor identification and documentation that make it impossible to classify acute situations under the diagnosis of malignant hyperthermia crisis. As a result, there are no statistical data in this field, and only case reports with a broad spectrum of suspected trigger mechanisms have been published. The case described in this report is a proved example of a non-anesthesia-related triggering of MH in a 21-year-old man who had had an anesthetic-induced MH manifestation in childhood, which was confirmed with an in vitro contracture test. After visiting a restaurant, he became unconscious and convulsive after consuming a high level of alcohol (2.9/1000). The first cardiocirculatory arrest occurred directly before hospitalization. After admission, the patient showed a full-blown MH episode whose subsequent fatality was unavoidable in spite of adapted and optimal therapy. Suspected trigger mechanisms seem to be multifactoral (excessive alcohol consumption, over-heating, mental stress) as a forensic investigation did not point to any particular signs of typical trigger substances. The case demonstrates again that an MH attack might be triggered under certain non-anaesthesia-related situations. For patients with an MH disposition, additional information on their behavior outside the hospital is required.

  13. Porcine malignant hyperthermia susceptibility: hypersensitive calcium-release mechanism of skeletal muscle sarcoplasmic reticulum.

    Science.gov (United States)

    O'Brien, P J

    1986-01-01

    This study tested the hypothesis that calcium-release from sarcoplasmic reticulum isolated from malignant hyperthermia swine had abnormal concentration-dependency on release modulators. Halothane stimulated half-maximal calcium-release at similar concentrations for malignant hyperthermia and control sarcoplasmic reticulum (0.10 +/- 0.04 mM). However, concentrations causing half-maximal calcium-release were lower for malignant hyperthermia sarcoplasmic reticulum (P less than 0.001) by an order of magnitude for Ca2+ (28.1 +/- 8.3 versus 1.23 +/- 0.45 nM), adenosine triphosphate (0.33 +/- 0.09 versus 0.023 +/- 0.014 mM) and caffeine (7.79 +/- 1.56 versus 0.80 +/- 0.44 mM). Half-maximal inhibition by Mg2+ occurred at threefold higher concentrations for malignant hyperthermia sarcoplasmic reticulum (0.23 +/- 0.02 versus 0.78 +/- 0.17 mM). The Ca2+-sensitivity curves for calcium-release by sarcoplasmic reticulum isolated from heterozygotes for the malignant hyperthermia-defect were indistinguishable from the averages of the curves for controls and malignant hyperthermia-homozygotes. Results of this study suggest that malignant hyperthermia is initiated due to a hypersensitive calcium-release mechanism which is inherited in an autosomal, codominant pattern and may be diagnosed using calcium-release sensitivity-tests on isolated sarcoplasmic reticulum. Images Fig. 1. PMID:3742367

  14. Application and possible mechanisms of combining LLLT (low level laser therapy), infrared hyperthermia and ionizing radiation in the treatment of cancer

    Science.gov (United States)

    Abraham, Edward H.; Woo, Van H.; Harlin-Jones, Cheryl; Heselich, Anja; Frohns, Florian

    2014-02-01

    Benefit of concomitant infrared hyperthermia and low level laser therapy and ionizing radiation is evaluated in this study. The purpose/objectives: presentation with locally advanced bulky superficial tumors is clinically challenging. To enhance the efficacy of chemotherapy and IMRT (intensity-modulated radiation therapy) and/or electron beam therapy we have developed an inexpensive and clinically effective infrared hyperthermia approach that combines black-body infrared radiation with halogen spectrum radiation and discrete wave length infrared clinical lasers LLLT. The goal is to produce a composite spectrum extending from the far infrared to near infrared and portions of the visible spectrum with discrete penetrating wavelengths generated by the clinical infrared lasers with frequencies of 810 nm and/or 830 nm. The composite spectrum from these sources is applied before and after radiation therapy. We monitor the surface and in some cases deeper temperatures with thermal probes, but use an array of surface probes as the limiting safe thermal constraint in patient treatment while at the same time maximizing infrared entry to deeper tissue layers. Fever-grade infrared hyperthermia is produced in the first centimeters while non-thermal infrared effects act at deeper tissue layers. The combination of these effects with ionizing radiation leads to improved tumor control in many cancers.

  15. Preliminary results of M-VAC chemotherapy combined with mild hyperthermia, a new therapeutic strategy for advanced or metastatic transitional cell carcinoma of the urothelium.

    Science.gov (United States)

    Yamada, Yoshiaki; Itoh, Youko; Aoki, Shigeyuki; Nakamura, Kogenta; Taki, Tomohiro; Naruse, Katsuya; Tobiume, Motoi; Zennami, Kenji; Katsuda, Remi; Kato, Yoshiharu; Watanabe, Masahito; Nishikawa, Genya; Minami, Miwako; Nakahira, Mariko; Ukai, Sayaka; Sawada, Masaki; Kitamura, Akiko; Honda, Nobuaki

    2009-11-01

    We evaluated the efficacy and safety of M-VAC chemotherapy combined with mild hyperthermia, a new therapeutic strategy for advanced metastatic transitional cell carcinoma of the urothelium. The subjects were 12 patients diagnosed with advanced metastatic transitional cell carcinoma of the urothelium. For mild hyperthermia, the patients' oral temperature was elevated to about 38 degrees C by heating for 20 min and retaining the heat for 20 min with a far-infrared heater. The antitumor effect was evaluated according to the RECIST, while adverse drug reactions were assessed based on the NCI-CTC. The antitumor effect was rated as partial remission (PR) in 10 of the 12 patients and stable disease in 2 patients, with an efficacy rate of 83% (10/12). All 10 patients who had achieved PR received three courses of treatment. Of the 12 patients, 5 died during the observation period, with survival for 9-23 months (mean: 15.6 months). Adverse drug reactions included myelosuppression in all patients (Grade 3 in 4 patients, Grade 4 in 8), and gastrointestinal toxicity, such as nausea or vomiting, which was mild (Grade 0 in 2 patients, Grade 1 in 8, Grade 2 in 1, Grade 3 in 1). The results of the present study suggest that M-VAC chemotherapy combined with mild hyperthermia, which potentiates the anticancer effect and reduces adverse drug reactions such as gastrointestinal symptoms, is a useful and safe method for the treatment of advanced transitional cell carcinoma of the urothelium.

  16. Complaint-adaptive power density optimization as a tool for HTP-guided steering in deep hyperthermia treatment of pelvic tumors

    International Nuclear Information System (INIS)

    Canters, R A M; Franckena, M; Zee, J van der; Rhoon, G C van

    2008-01-01

    For an efficient clinical use of HTP (hyperthermia treatment planning), optimization methods are needed. In this study, a complaint-adaptive PD (power density) optimization as a tool for HTP-guided steering in deep hyperthermia of pelvic tumors is developed and tested. PD distribution in patients is predicted using FE-models. Two goal functions, Opt1 and Opt2, are applied to optimize PD distributions. Optimization consists of three steps: initial optimization, adaptive optimization after a first complaint and increasing the weight of a region after recurring complaints. Opt1 initially considers only target PD whereas Opt2 also takes into account hot spots. After patient complaints though, both limit PD in a region. Opt1 and Opt2 are evaluated in a phantom test, using patient models and during hyperthermia treatment. The phantom test and a sensitivity study in ten patient models, show that HTP-guided steering is most effective in peripheral complaint regions. Clinical evaluation in two groups of five patients shows that time between complaints is longer using Opt2 (p = 0.007). However, this does not lead to significantly different temperatures (T50s of 40.3 (Opt1) versus 40.1 deg. C (Opt2) (p = 0.898)). HTP-guided steering is feasible in terms of PD reduction in complaint regions and in time consumption. Opt2 is preferable in future use, because of better complaint reduction and control.

  17. [Scrotal temperature in 258 healthy men, randomly selected from a population of men aged 18 to 23 years old. Statistical analysis, epidemiologic observations, and measurement of the testicular diameters].

    Science.gov (United States)

    Valeri, A; Mianné, D; Merouze, F; Bujan, L; Altobelli, A; Masson, J

    1993-06-01

    Scrotal hyperthermia can induce certain alterations in spermatogenesis. The basal scrotal temperature used to define hyperthermia is usually 33 degrees C. However, no study, conducted according to a strict methodology has validated this mean measurement. We therefore randomly selected 258 men between the ages of 18 and 23 years from a population of 2,000 young French men seen at the National Service Selection Centre in order to measure the scrotal temperature over each testis and in the median raphe in order to determine the mean and median values for these temperatures. For a mean room temperature of 23 +/- 0.5 degrees C with a range of 18 to 31 degrees C, the mean right and left scrotal temperature was 34.2 +/- 0.1 degree C and the mean medioscrotal temperature was 34.4 +/- 0.1 degree C. Scrotal temperature was very significantly correlated to room temperature and its variations. It was therefore impossible to define a normal value for scrotal temperature. Only measurement of scrotal temperature at neutral room temperature, between 21 and 25 degrees C, is able to provide a reference value for scrotal temperature. In this study, the mean scrotal temperature under these conditions was 34.4 +/- 0.2 degree C, i.e. 2.5 degrees C less than body temperature. In the 12.9% of cases with left varicocele, left scrotal temperature was significantly higher than in the absence of varicocele and was also higher than right Scrotal temperature. The authors also determined the dimensions of the testes.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Study and realization of a new humid air generator; towards the definition of a dew temperature reference; Etude et realisation d'un nouveau generateur d'air humide; vers la definition d'une reference en temperature de rosee

    Energy Technology Data Exchange (ETDEWEB)

    Blanquart, B.

    2001-03-01

    The air humidity is an important parameter for several biological and physico-chemical processes. The aim of this thesis is the direct determination of the dew temperature without any link with the gravimetric reference. This document presents the realization and adjusting of a new humid air generator for the -80 deg. C to +15 deg. C range and the uncertainty linked with the dew temperature of the humid air generated. The first chapter recalls the definitions of humid air related data and the principles of the apparatuses used for the measurement of air humidity. The second chapter deals with temperature measurements while chapter 3 describes the new humid air generator built around an 'ideal' cell based on the theoretical definition of the dew temperature. Technical constraints due to temperature measurement and to hygrometers calibration are progressively integrated and introduced and lead to the practical realization of the device. Differences between the ideal cell and the prototype are estimated using a theoretical approach of mass and heat exchanges coupled with experimental results obtained with a previous prototype. Chapter 4 presents a first status of the device uncertainties with some possibilities of reduction of these uncertainties. (J.S.)

  19. The effects of isatin (indole-2, 3-dione on pituitary adenylate cyclase-activating polypeptide-induced hyperthermia in rats

    Directory of Open Access Journals (Sweden)

    Tóth Gábor

    2002-02-01

    Full Text Available Abstract Background Previous studies have demonstrated that centrally administered natriuretic peptides and pituitary adenylate cyclase-activating polypeptide-38 (PACAP-38 have hyperthermic properties. Isatin (indole-2, 3-dione is an endogenous indole that has previously been found to inhibit hyperthermic effects of natriuretic peptides. In this study the aim was to investigate the effects of isatin on thermoregulatory actions of PACAP-38, in rats. Results One μg intracerebroventricular (icv. injection of PACAP-38 had hyperthermic effect in male, Wistar rats, with an onset of the effect at 2 h and a decline by the 6th h after administration. Intraperitoneal (ip. injection of different doses of isatin (25-50 mg/kg significantly decreased the hyperthermic effect of 1 μg PACAP-38 (icv., whereas 12.5 mg/kg isatin (ip. had no inhibiting effect. Isatin alone did not modify the body temperature of the animals. Conclusion The mechanisms that participate in the mediation of the PACAP-38-induced hyperthermia may be modified by isatin. The capability of isatin to antagonize the hyperthermia induced by all members of the natriuretic peptide family and by PACAP-38 makes it unlikely to be acting directly on receptors for natriuretic peptides or on those for PACAP in these hyperthermic processes.

  20. Changes in regional blood flow of normal and tumor tissues following hyperthermia and combined X-ray irradiation

    International Nuclear Information System (INIS)

    Suga, Kazuyoshi

    1986-01-01

    Hyperthermia and X-ray irradiation were given to Ehrlich tumors, which were induced in the ventrum of the right hind foot of ICR mice, and to the normal tissues. Their effects on regional blood flow were examined using Xe-133 local clearance method. Blood flow of the normal tissues remained unchanged by heating at 41 deg C for 30 minutes, and increased by heating at 43 deg C and 45 deg C for 30 minutes. On the contrary, blood flow of the tumors decreased with an increase in temperature. When hypertermia (43 deg C for 30 minutes) was combined with irradiation of 30 Gy, decrease in blood flow of the tumors was greater than the normal tissues at 24 hours. Blood flow of the tumors depended on tumor size. The decreased amount of blood flow by hyperthermia was more for tumors > 250 mm 3 than tumors 3 . Blood flow ratios of tumor to normal tissues were also smaller in tumors > 250 mm 3 than tumors 3 . In the case of tumors 3 , blood flow tended to return to normal at 3 hr after heating at 43 deg C for 30 min. However, this was not seen in tumors > 250 mm 3 . (Namekawa, K.)

  1. Folic acid-conjugated Fe3O4 magnetic nanoparticles for hyperthermia and MRI in vitro and in vivo

    International Nuclear Information System (INIS)

    Jiang, Q.L.; Zheng, S.W.; Hong, R.Y.; Deng, S.M.; Guo, L.; Hu, R.L.; Gao, B.; Huang, M.; Cheng, L.F.; Liu, G.H.; Wang, Y.Q.

    2014-01-01

    The folic acid (FA)-conjugated Fe 3 O 4 magnetic nanoparticles (MNPs) were synthesized by co-precipitation of Fe 3+ and Fe 2+ solution followed by surface modification with carboxymethyl dextran (CMD) to form carboxymethyl group terminated MNPs, then FA was conjugated with the carboxyl group functionalized MNPs. The morphology and properties of obtained nanoparticles were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV–visible spectra (UV–vis), transmission electron microscopy (TEM), dynamic light scattering (DLS), vibrating sample magnetometer (VSM) and thermogravimetric analysis (TGA). The FA-conjugated MNPs exhibited relatively high saturation magnetization and fast magneto-temperature response which could be applied to hyperthermia therapy. To determine the accurate targeting effect of FA, we chose FA-conjugated MNPs as MRI contrast enhancement agent for detection of KB cells with folate receptor over-expression in vitro and in vivo. The results show that these magnetic nanoparticles appear to be the promising materials for local hyperthermia and MRI.

  2. Description and characterization of the novel hyperthermia- and thermoablation-system MFHregistered300F for clinical magnetic fluid hyperthermia

    International Nuclear Information System (INIS)

    Gneveckow, Uwe; Jordan, Andreas; Scholz, Regina; Bruess, Volker; Waldoefner, Norbert; Ricke, Jens; Feussner, Annelie; Hildebrandt, Bert; Rau, Beate; Wust, Peter

    2004-01-01

    Magnetic fluid hyperthermia (MFH) is a new approach to deposit heat power in deep tissues by overcoming limitations of conventional heat treatments. After infiltration of the target tissue with nanosized magnetic particles, the power of an alternating magnetic field is transformed into heat. The combination of the 100 kHz magnetic field applicator MFH registered 300F and the magnetofluid (MF), which both are designed for medical use, is investigated with respect to its dosage recommendations and clinical applicability. We found a magnetic field strength of up to 18 kA/m in a cylindrical treatment area of 20 cm diameter and aperture height up to 300 mm. The specific absorption rate (SAR) can be controlled directly by the magnetic field strength during the treatment. The relationship between magnetic field strength and the iron normalized SAR (SAR Fe ) is only slightly depending on the concentration of the MF and can be used for planning the target SAR. The achievable energy absorption rates of the MF distributed in the tissue is sufficient for either hyperthermia or thermoablation. The fluid has a visible contrast in therapeutic concentrations on a CT scanner and can be detected down to 0.01 g/l Fe in the MRI. The system has proved its capability and practicability for heat treatment in deep regions of the human body

  3. Disorders of body temperature.

    Science.gov (United States)

    Gomez, Camilo R

    2014-01-01

    The human body generates heat capable of raising body temperature by approximately 1°C per hour. Normally, this heat is dissipated by means of a thermoregulatory system. Disorders resulting from abnormally high or low body temperature result in neurologic dysfunction and pose a threat to life. In response to thermal stress, maintenance of normal body temperature is primarily maintained by convection and evaporation. Hyperthermia results from abnormal temperature regulation, leading to extremely elevated body temperature while fever results from a normal thermoregulatory mechanism operating at a higher set point. The former leads to specific clinical syndromes with inability of the thermoregulatory mechanism to maintain a constant body temperature. Heat related illness encompasses heat rash, heat cramps, heat exhaustion and heat stroke, in order of severity. In addition, drugs can induce hyperthermia and produce one of several specific clinical syndromes. Hypothermia is the reduction of body temperature to levels below 35°C from environmental exposure, metabolic disorders, or therapeutic intervention. Management of disorders of body temperature should be carried out decisively and expeditiously, in order to avoid secondary neurologic injury. © 2014 Elsevier B.V. All rights reserved.

  4. Influence of local hyperthermia induced by micro-waves and X-rays on the Walker carcinoma of the rat

    International Nuclear Information System (INIS)

    Brueckner, V.; Zywietz, F.; Jung, H.

    1979-01-01

    The authors studied the influence on the solid Walker carcinoma in the rat exerted by a slight hyperthermia induced by micro-waves, which was applied alone and combined with X-ray irradiations. It could be demonstrated that the tumor has the same temperature as the sub-peritoneal region. Thus the final temperature reached by the treatment with microwaves can be exactly controlled. Heating up to 41 0 C for 30 minutes produces an increase of the survival rate of animals with tumors of 2 to 6 grams from 17% to 27%, whereas the healing rate is 57% after an X-ray irradiation with 1130 rad and 75% after the combined treatment. Each of the three therapy methods produces a significant prolongation of the survival time of the dying animals. The disadvantes of an anisologic tumor-host system are discussed on the basis of the results achieved. (orig.) [de

  5. Estimation of quasi-static J–R curves from Charpy energy and adaptation to ASTM E 1921 reference temperature estimation of ferritic steels

    International Nuclear Information System (INIS)

    Sreenivasan, P.R.

    2014-01-01

    Many researchers had suggested a sort of scaling procedure for predicting the quasi-static J–R curves from dynamic J–R curves obtained from instrumented Charpy V-notch (CVN) impact tests using key-curve, compliance or other procedures. Chaouadi, based on extensive tests and literature data, had quantitatively formalized the method and suggested general applicability of his method for a class of steels. In this paper, first, the Chauoadi-procedure is tried on some selected data from the literature (including the data used by Chaouadi and other workers) and an adaptation of the method is suggested using Wallin's as well as Landes's lower bound methods for upper-shelf J–R curve estimation from CVN energy. Using Chaouadi and other data as the benchmark, suitable scaling factors have been determined that enable estimation of quasi-static J–R curves from CVN energy alone, without the need for dynamic CVN J–R curves. The final formulae are given. This new method can be called modified Wallin–Landes procedure. Then this method is applied to fracture toughness and reference temperature (T 0 – ASTM E-1921) estimation from the full Charpy-transition data. The results are compared with those from the author's IGC-procedure, and modifications, if any, are suggested. Based on the new results, it is suggested that the IGC-procedure may be modified as: final T Q-est = T Q-IGC for T Q-Sch dy ≤ 20 °C (in the IGC-procedure the dividing temperature was 60 °C); and for T Q-Sch dy > 20 °C, T Q-IGC = T Q-WLm (different from the IGC-procedre and subscript WLm indicating modified Wallin–Landes procedure). For the 59 or more steels examined (including highly irradiated steels), the T Q-WL estimates at higher temperatures are consistent and conservative; a few non-conservative values are acceptably less than 20 °C, whereas other predictions show non-conservatism of up to 40–50 °C. At lower temperatures, T Q-IGC is consistently conservative and not over

  6. Effect of hyperthermia on the radiation response of the mouse jejunum

    International Nuclear Information System (INIS)

    Merino, O.R.; Peters, L.J.; Mason, K.A.; Withers, H.R.

    1978-01-01

    The experiments reported show that the effect of radiation on the gut mucosa may be significantly enhanced by moderate hyperthermia (41 to 44 0 C) that is applied for 30 min before or after irradiation. The predominant effect of combined heat and radiation was to displace the radiation survival curves of jejunal crypt stem cells to the left without a significant change in slope. The degree of displacement was temperature-dependent from 41 to 44 0 C, and was greater when heating preceded irradiation. The thermal enhancement ratio (TER) for crypt stem cell survival is not constant but increases with higher surviving fractions. At the isoeffect level of 20 surviving stem cells per jejunal circumference, the TER reached a maximum of 4.7 when heating for 30 min at 44 0 C preceded irradiation. Although direct comparisons of published TER's for different tissues cannot be made because the levels of cellular survival to produce given endpoints differ, it appears that the gut may be particularly vulnerable to radiation damage when preheated to temperatures over 42 0 C. It is important for the safety of human combined modality studies first that specific information concerning the tolerance of all critical normal tissues to heat and irradiation be obtained, and second that the likelihood of an increase in TER with fractionated exposures to heat and irradiation be appreciated

  7. Modelling mass and heat transfer in nano-based cancer hyperthermia.

    Science.gov (United States)

    Nabil, M; Decuzzi, P; Zunino, P

    2015-10-01

    We derive a sophisticated mathematical model for coupled heat and mass transport in the tumour microenvironment and we apply it to study nanoparticle delivery and hyperthermic treatment of cancer. The model has the unique ability of combining the following features: (i) realistic vasculature; (ii) coupled capillary and interstitial flow; (iii) coupled capillary and interstitial mass transfer applied to nanoparticles; and (iv) coupled capillary and interstitial heat transfer, which are the fundamental mechanisms governing nano-based hyperthermic treatment. This is an improvement with respect to previous modelling approaches, where the effect of blood perfusion on heat transfer is modelled in a spatially averaged form. We analyse the time evolution and the spatial distribution of particles and temperature in a tumour mass treated with superparamagnetic nanoparticles excited by an alternating magnetic field. By means of numerical experiments, we synthesize scaling laws that illustrate how nano-based hyperthermia depends on tumour size and vascularity. In particular, we identify two distinct mechanisms that regulate the distribution of particle and temperature, which are characterized by perfusion and diffusion, respectively.

  8. Laboratory prototype for experimental validation of MR-guided radiofrequency head and neck hyperthermia

    Science.gov (United States)

    Paulides, M. M.; Bakker, J. F.; Hofstetter, L. W.; Numan, W. C. M.; Pellicer, R.; Fiveland, E. W.; Tarasek, M.; Houston, G. C.; van Rhoon, G. C.; Yeo, D. T. B.; Kotek, G.

    2014-05-01

    Clinical studies have established a strong benefit from adjuvant mild hyperthermia (HT) to radio- and chemotherapy for many tumor sites, including the head and neck (H&N). The recently developed HYPERcollar allows the application of local radiofrequency HT to tumors in the entire H&N. Treatment quality is optimized using electromagnetic and thermal simulators and, whenever placement risk is tolerable, assessed using invasively placed thermometers. To replace the current invasive procedure, we are investigating whether magnetic resonance (MR) thermometry can be exploited for continuous and 3D thermal dose assessment. In this work, we used our simulation tools to design an MR compatible laboratory prototype applicator. By simulations and measurements, we showed that the redesigned patch antennas are well matched to 50 Ω (S11<-10 dB). Simulations also show that, using 300 W input power, a maximum specific absorption rate (SAR) of 100 W kg-1 and a temperature increase of 4.5 °C in 6 min is feasible at the center of a cylindrical fat/muscle phantom. Temperature measurements using the MR scanner confirmed the focused heating capabilities and MR compatibility of the setup. We conclude that the laboratory applicator provides the possibility for experimental assessment of the feasibility of hybrid MR-HT in the H&N region. This versatile design allows rigorous analysis of MR thermometry accuracy in increasingly complex phantoms that mimic patients' anatomies and thermodynamic characteristics.

  9. In vivo hyperthermia effect induced by high-intensity pulsed ultrasound

    International Nuclear Information System (INIS)

    Cui Wei-Cheng; Tu Juan; Li Qian; Fan Ting-Bo; Zhang Dong; Chen Wei-Zhong; Joo-Ha Hwang; Chen Jing-Hai

    2012-01-01

    Hyperthermia effects (39–44 °C) induced by pulsed high-intensity focused ultrasound (HIFU) have been regarded as a promising therapeutic tool for boosting immune responses or enhancing drug delivery into a solid tumor. However, previous studies also reported that the cell death occurs when cells are maintained at 43 °C for more than 20 minutes. The aim of this study is to investigate thermal responses inside in vivo rabbit auricular veins exposed to pulsed HIFU (1.17 MHz, 5300 W/cm 2 , with relatively low-duty ratios (0.2%–4.3%). The results show that: (1) with constant pulse repetition frequency (PRF) (e.g., 1 Hz), the thermal responses inside the vessel will increase with the increasing duty ratio; (2) a temperature elevation to 43 °C can be identified at the duty ratio of 4.3%; (3) with constant duty ratios, the change of PRF will not significantly affect the temperature measurement in the vessel; (4) as the duty ratios lower than 4.3%, the presence of microbubbles will not significantly enhance the thermal responses in the vessel, but will facilitate HIFU-induced inertial cavitation events. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  10. Obese type 2 diabetics have a blunted hypotensive response to acute hyperthermia therapy that does not affect the perception of thermal stress or physiological strain compared to healthy adults.

    Science.gov (United States)

    Rivas, Eric; Newmire, Dan E; Ben-Ezra, Vic

    2016-10-15

    The objective of this study was to test the hypothesis that a hyperthermia-hypotensive challenge via whole body hot water immersion would alter the perception of hyperthermia and physiological strain in obese type 2 diabetics (T2DM) compared to healthy non-obese (HC) individuals. Additionally, we hypothesize that the mechanisms would be attributed to impaired blood pressure adjustments and afferent signals (via changes in internal and mean skin temperatures). In random order, eleven obese T2DM (50±12y, 45±7% fat mass, 7.5±1.8% HbA1c) and nine similar aged (41±14y, P>0.05) HC non-obese (33±8% fat mass, Pperception of thermal sensation (TS, scale range: 1-13), calculated physiological strain (PSI), internal (Tre, rectal) and mean skin (Tsk) temperatures, heart rate (HR) and blood pressures (BP) were the primary dependent variables. Hyperthermia similarly increased Tre by 1.4±0.4°C, Tsk by 6.5±0.8°C and HR by 34±8bpm in both groups (P>0.5). Hyperthermia reduced diastolic BP (27% in T2DM and 33% in HC, Pdifferent between groups. Pearson product correlation reported strong correlations (r=0.69-0.89) with Tre and Tsk with TS in both populations. The linear stepwise regression analysis revealed similar relative contributions for Tre (~60%) and Tsk (~40%) on TS for both groups. These data indicate that obese T2DM with moderate metabolic control have an attenuated hyperthermia-hypotensive response that does not affect TS and PSI. This also may suggest behavioral thermoregulation is intact in this study group. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Enhancement of the cytotoxicity of radiosensitizers by modest hyperthermia: the electron-affinity relationship

    Energy Technology Data Exchange (ETDEWEB)

    Rajaratnam, S.; Adams, G.E.; Stratford, I.J.; Clarke, C.

    1982-01-01

    The cytotoxicity of 3 electron-affinic radiosensitizers has been studied in Chinese hamster V-79 cells as a function of pH and modest hyperthermia. When equitoxic concentrations were used and temperature was increased from 34 to 41/sup 0/C metronidazole, the compound with the lowest electron affinity showed the greatest enhancement of hypoxic-cell toxicity, and nitrofurantoin, the compound with the highest electron affinity, the least. The results can be explained if the mechanisms of toxicity involves a redox reaction, since it would be expected that the least toxic compound (lowest electron affinity) would have the largest activation energy and hence the greatest temperature effect. This appears to hold for these 3 compounds. Experiments also showed that nitrofurantoin which exhibits no increase in toxicity when the temperature was increased from 37 to 41/sup 0/C at pH 7.4, showed an increase in toxicity for the same temperature change at the pH of 7.0 and 6.6. Under aerobic conditions only metronidazole showed significant toxicity at 41/sup 0/C, where the differential between aerobic and hypoxic cell toxicity was minimal, both at pH 7.4, and at the low pH values of 7.0 and 6.6. In the clinical setting there is evidence that tumor cells are at a lower pH than their surrounding normal tissues. Hypoxic-cell cytotoxicity is enhanced at low pH, and even further enhanced at low pH in combination with a temperature of 41/sup 0/C. However, this finding correlates conversely with electron affinity.

  12. Findings in young pigs following combined treatment by hyperthermia and irradiation

    International Nuclear Information System (INIS)

    Schorcht, J.; Herrmann, T.; Barke, R.; Johannsen, U.

    1985-01-01

    In a pilot study, 8 store pigs were submitted to a combined treatment with hyperthermia (5 x 60 min; 42 0 C in the thoracic region) followed by telecobalt irradiation of the right lung (5 x 4 Gy). Radiologic checks of the thoracic organs and laboratory diagnostics provided useful data as to the temporal course of the radiogenic pulmonary affections and the tolerability of fractionated whole-body hyperthermia including superimposed local heating on store pigs. Histologic examinations of sections of heated and irradiated (right) as compared to exclusively heated (left) lung lobes of 4 animals suggested that hyperthermia exerted a radiosensitizing effect on the right lungs. Histologically confirmed irreversible lung fibrosis occurred there after exposure to even lower total doses following hyperthermia as compared to sole irradiation. (author)

  13. Differences in the Onset and Severity of Symptoms of Malignant Hyperthermia With Different Inhalational Anesthetics

    National Research Council Canada - National Science Library

    Solberg, Alison

    1999-01-01

    .... The purpose of this study was to identify if there is a significant difference in the onset and severity of signs and symptoms of malignant hyperthermia in those MH-susceptible patients who received...

  14. Assessment of immunomodulating action of combined therapy with UHF-hyperthermia in children with osteogenic sarcoma

    International Nuclear Information System (INIS)

    Neprina, G.S.; Panteleeva, E.S.; Vatin, O.E.; Bizer, V.A.; Bojko, I.N.

    1989-01-01

    The paper is concerned with immunological evaluation of different stages of combined therapy with local UHF-hyperthermia in children with osteogenic sarcoma. Combined therapy (polychemo- and raditherapy) was shown to cause a decrease in the number of immunocompetent cells, to enhance dysbalance of immunoregulatory T-lymphocytes, to weaken T-lymphocyte function on PHA; immunosuppressive action of combined therapy did not depend on a tumor site. The incorporation of UHF-hyperthermia in the therapeutic scheme weakened the manifestations of secondary immunodeficiency, got back to normal structure of T-lymphocyte population. A favorable immunomodulating effect of hyperthermia was more frequently observed in patients with crural bone tumors. The effect of hyperthermia was revealed after direct influence of thermotherapy but it was absent in continuation of combined treatment

  15. Reference core design Mark-I and -II of the experimental, multi-purpose, high-temperature, gas-cooled reactor

    International Nuclear Information System (INIS)

    Shindo, Ryuiti; Hirano, Mitsumasa; Aruga, Takeo; Yasukawa, Sigeru

    1977-10-01

    Reactivity worth of the control rods and power distribution in the initial hot-clean core of reference core design Mark-I and -II have been studied. The need for burnable poison was confirmed, because of the limitations in number, diameter and reactivity worth of the control rods due to structures of pressure vessel and fuel element and to safety of the core. While the initial excess reactivity is reduced by use of the burnable poison, the recovery of core reactivity with burnup of the burnable poison requires a complicated withdrawal sequence of the control rods. The radial power gradient in the core is not large, due to orifice control of the coolant helium flow, effectiveness of the reflector in the small core and continuous distribution of burnup in the core by one-batch refuelling scheme. The local peaking factor in unit orifice regions, therefore, is the most important core design. Control of the axial power distribution is necessary to reduce the maximum fuel temperature and the exponential power distribution peaked toward the inlet of the core is most suitable. However, insertion of the control rods from top of the core disturbs the axial power distribution, so this effect must be considered in design of the withdrawal sequence of control rods. Nuclear properties of the core were revealed from results of the study for the initial hot-clean core. (auth.)

  16. Experimental ex-vivo validation of PMMA-based bone cements loaded with magnetic nanoparticles enabling hyperthermia of metastatic bone tumors

    Directory of Open Access Journals (Sweden)

    Mariem Harabech

    2017-05-01

    Full Text Available Percutaneous vertebroplasty comprises the injection of Polymethylmethacrylate (PMMA bone cement into vertebrae and can be used for the treatment of compression fractures of vertebrae. Metastatic bone tumors can cause such compression fractures but are not treated when injecting PMMA-based bone cement. Hyperthermia of tumors can on the other hand be attained by placing magnetic nanoparticles (MNPs in an alternating magnetic field (AMF. Loading the PMMA-based bone cement with MNPs could both serve vertebra stabilization and metastatic bone tumor hyperthermia when subjecting this PMMA-MNP to an AMF. A dedicated pancake coil is designed with a self-inductance of 10 μH in series with a capacitance of 0.1 μF that acts as resonant inductor-capacitor circuit to generate the AMF. The thermal rise is appraised in beef vertebra placed at 10 cm from the AMF generating circuit using optical temperatures sensors, i.e. in the center of the PMMA-MNP bone cement, which is located in the vicinity of metastatic bone tumors in clinical applications; and in the spine, which needs to be safeguarded to high temperature exposures. Results show a temperature rise of about 7 °C in PMMA-MNP whereas the temperature rise in the spine remains limited to 1 °C. Moreover, multicycles heating of PMMA-MNP is experimentally verified, validating the technical feasibility of having PMMA-MNP as basic component for percutaneous vertebroplasty combined with hyperthermia treatment of metastatic bone tumors.

  17. Surface functionalized biocompatible magnetic nanospheres for cancer hyperthermia.

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X.; Novosad, V.; Rozhkova, E. A.; Chen, H.; Yefremenko, V.; Pearson, J.; Torno, M.; Bader, S. D.; Rosengart, A. J.; Univ. Chicago Pritzker School of Medicine

    2007-06-01

    We report a simplified single emulsion (oil-in-water) solvent evaporation protocol to synthesize surface functionalized biocompatible magnetic nanospheres by using highly concentrated hydrophobic magnetite (gel) and a mixture of poly(D,L lactide-co-glycolide) (PLGA) and poly(lactic acid-block-polyethylene glycol-maleimide) (PLA-PEG-maleimide) (10:1 by mass) polymers. The as-synthesized particles are approximately spherical with an average diameter of 360-370 nm with polydispersity index of 0.12-0.18, are surface-functionalized with maleimide groups, and have saturation magnetization values of 25-40 emu/g. The efficiency of the heating induced by 400-kHz oscillating magnetic fields is compared for two samples with different magnetite loadings. Results show that these nanospheres have the potential to provide an efficient cancer-targeted hyperthermia.

  18. Metastatic spreading and growth of rhabdomyosarcoma in exposure to hyperglycemia, hyperthermia and ionizing radiation

    International Nuclear Information System (INIS)

    Ul'yanenko, S.E.; Salamatina, N.A.; Dedenkov, A.N.

    1985-01-01

    Under the effect of local UHF-hyperthermia, short-term hyperglycemia and ionizing radiation on metastasing strain of rhabdomysarcoma an increase in metastatic spreading or stimulated growth of primary tumor are not noticed. Otherwise, it is stated that hyperglycemia and hyperthermia thrice-used prevent from metastatic spreading of the tumor. Ionizing radiation decelerates both tumor growth and to a least extent its metastatic spreading

  19. Polymodification. Short-term hyperglycemia and local hyperthermia in hypoxiradiotherapy of transplantable solid tumors

    International Nuclear Information System (INIS)

    Kozin, S.V.; Krimker, V.M.; Yarmonenko, S.P.

    1984-01-01

    Application possibilities of hyperglycemia and local hyperthermia in combination with hypoxiradiotherapy of solid tumors, have been evaluated. The experiments conducted have shown the great possibilities of combined use of radiation, hyperglycemia, hyperthermia, for selective affection of tumours, and application of gaseous hypoxia during irradiation - for simultaneous principal protection of normal tissues. Interaction of all the agents will undoubtedly require a versatile study to develop the optimum regimes of action

  20. Immunohistochemical study on the fetal rat pituitary in hyperthermia-induced exencephaly

    OpenAIRE

    Watanabe, Yuichi G.; 渡辺, 勇一

    2002-01-01

    Hyperthermia of fetal rats is known to cause malformations of various organs including brain. The present study was carried out to investigate the effect of the hyperthermia-induced brain damages on the development of the adenohypophysis. Mother rats of Day 9.5 of pregnancy were anesthetized and immersed in hot water (43℃) for 15 min. At Day 21.5 of gestation, fetuses were removed by caesarian section and examined for exencephaly. Hyperthermal stress induced varying degrees of exencephaly in ...

  1. Immunohistochemical Study on the Fetal Rat Pituitary in Hyperthermia-lnduced Exencephaly(Endocrinology)

    OpenAIRE

    Yuichi G., Watanabe; Department of Biology, Faculty of Science, Niigata University

    2002-01-01

    Hyperthermia of fetal rats is known to cause malformations of various organs including brain. The present study was carried out to investigate the effect of the hyperthermia-induced brain damages on the development of the adenohypophysis. Mother rats of Day 9.5 of pregnancy were anesthetized and immersed in hot water (43℃) for 15 min. At Day 21.5 of gestation, fetuses were removed by caesarian section and examined for exencephaly. Hyperthermal stress induced varying degrees of exencephaly in ...

  2. Pharmacokinetics, Tissue Distribution and Therapeutic Effect of Cationic Thermosensitive Liposomal Doxorubicin Upon Mild Hyperthermia

    OpenAIRE

    Dicheva, Bilyana M.; Seynhaeve, Ann L. B.; Soulie, Thomas; Eggermont, Alexander M. M.; ten Hagen, Timo L. M.; Koning, Gerben A.

    2015-01-01

    textabstractPurpose: To evaluate pharmacokinetic profile, biodistribution and therapeutic effect of cationic thermosensitive liposomes (CTSL) encapsulating doxorubicin (Dox) upon mild hyperthermia (HT). Methods: Non-targe