Development of a spherically focused phased array transducer for ultrasonic image-guided hyperthermia

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Liu, Jingfei; Foiret, Josquin; Stephens, Douglas N.; Le Baron, Olivier; Ferrara, Katherine W.

2016-07-01

A 1.5 MHz prolate spheroidal therapeutic array with 128 circular elements was designed to accommodate standard imaging arrays for ultrasonic image-guided hyperthermia. The implementation of this dual-array system integrates real-time therapeutic and imaging functions with a single ultrasound system (Vantage 256, Verasonics). To facilitate applications involving small animal imaging and therapy the array was designed to have a beam depth of field smaller than 3.5 mm and to electronically steer over distances greater than 1 cm in both the axial and lateral directions. In order to achieve the required f number of 0.69, 1-3 piezocomposite modules were mated within the transducer housing. The performance of the prototype array was experimentally evaluated with excellent agreement with numerical simulation. A focal volume (2.70 mm (axial)  ×  0.65 mm (transverse)  ×  0.35 mm (transverse)) defined by the  -6 dB focal intensity was obtained to address the dimensions needed for small animal therapy. An electronic beam steering range defined by the  -3 dB focal peak intensity (17 mm (axial)  ×  14 mm (transverse)  ×  12 mm (transverse)) and  -8 dB lateral grating lobes (24 mm (axial)  ×  18 mm (transverse)  ×  16 mm (transverse)) was achieved. The combined testing of imaging and therapeutic functions confirmed well-controlled local heating generation and imaging in a tissue mimicking phantom. This dual-array implementation offers a practical means to achieve hyperthermia and ablation in small animal models and can be incorporated within protocols for ultrasound-mediated drug delivery.

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

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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)

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)

Hyperthermia enhances mapatumumab-induced apoptotic death through ubiquitin-mediated degradation of cellular FLIP(long) in human colon cancer cells.

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Song, X; Kim, S-Y; Zhou, Z; Lagasse, E; Kwon, Y T; Lee, Y J

2013-04-04

Colorectal cancer is the third leading cause of cancer-related mortality in the world; the main cause of death of colorectal cancer is hepatic metastases, which can be treated with hyperthermia using isolated hepatic perfusion (IHP). In this study, we report that mild hyperthermia potently reduced cellular FLIP(long), (c-FLIP(L)), a major regulator of the death receptor (DR) pathway of apoptosis, thereby enhancing humanized anti-DR4 antibody mapatumumab (Mapa)-mediated mitochondria-independent apoptosis. We observed that overexpression of c-FLIP(L) in CX-1 cells abrogated the synergistic effect of Mapa and hyperthermia, whereas silencing of c-FLIP in CX-1 cells enhanced Mapa-induced apoptosis. Hyperthermia altered c-FLIP(L) protein stability without concomitant reductions in FLIP mRNA. Ubiquitination of c-FLIP(L) was increased by hyperthermia, and proteasome inhibitor MG132 prevented heat-induced downregulation of c-FLIP(L). These results suggest the involvement of the ubiquitin-proteasome system in this process. We also found lysine residue 195 (K195) to be essential for c-FLIP(L) ubiquitination and proteolysis, as mutant c-FLIP(L) lysine 195 arginine (arginine replacing lysine) was left virtually un-ubiquitinated and was refractory to hyperthermia-triggered degradation, and thus partially blocked the synergistic effect of Mapa and hyperthermia. Our observations reveal that hyperthermia transiently reduced c-FLIP(L) by proteolysis linked to K195 ubiquitination, which contributed to the synergistic effect between Mapa and hyperthermia. This study supports the application of hyperthermia combined with other regimens to treat colorectal hepatic metastases.

In Vivo Imaging of Local Gene Expression Induced by Magnetic Hyperthermia

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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.

Hyperthermia-enhanced TRAIL- and mapatumumab-induced apoptotic death is mediated through mitochondria in human colon cancer cells.

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Song, Xinxin; Kim, Han-Cheon; Kim, Seog-Young; Basse, Per; Park, Bae-Hang; Lee, Byeong-Chel; Lee, Yong J

2012-05-01

Colorectal cancer is the third leading cause of cancer-related mortality in the world; death usually results from uncontrolled metastatic disease. Previously, we developed a novel strategy of TNF-related apoptosis-inducing ligand (Apo2L/TRAIL) in combination with hyperthermia to treat hepatic colorectal metastases. However, previous studies suggest a potential hepatocyte cytotoxicity with TRAIL. Unlike TRAIL, anti-human TRAIL receptor antibody induces apoptosis without hepatocyte toxicity. In this study, we evaluated the anti-tumor efficacy of humanized anti-death receptor 4 (DR4) antibody mapatumumab (Mapa) by comparing it with TRAIL in combination with hyperthermia. TRAIL, which binds to both DR4 and death receptor 5 (DR5), was approximately tenfold more effective than Mapa in inducing apoptosis. However, hyperthermia enhances apoptosis induced by either agent. We observed that the synergistic effect was mediated through elevation of reactive oxygen species, c-Jun N-terminal kinase activation, Bax oligomerization, and translocalization to the mitochondria, loss of mitochondrial membrane potential, release of cytochrome c to cytosol, activation of caspases, and increase in poly(ADP-ribose) polymerase cleavage. We believe that the successful outcome of this study will support the application of Mapa in combination with hyperthermia to colorectal hepatic metastases. Copyright © 2011 Wiley Periodicals, Inc.

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

Acute whole-body cooling for exercise-induced hyperthermia: a systematic review.

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McDermott, Brendon P; Casa, Douglas J; Ganio, Matthew S; Lopez, Rebecca M; Yeargin, Susan W; Armstrong, Lawrence E; Maresh, Carl M

2009-01-01

To assess existing original research addressing the efficiency of whole-body cooling modalities in the treatment of exertional hyperthermia. During April 2007, we searched MEDLINE, EMBASE, Scopus, SportDiscus, CINAHL, and Cochrane Reviews databases as well as ProQuest for theses and dissertations to identify research studies evaluating whole-body cooling treatments without limits. Key words were cooling, cryotherapy, water immersion, cold-water immersion, ice-water immersion, icing, fanning, bath, baths, cooling modality, heat illness, heat illnesses, exertional heatstroke, exertional heat stroke, heat exhaustion, hyperthermia, hyperthermic, hyperpyrexia, exercise, exertion, running, football, military, runners, marathoner, physical activity, marathoning, soccer, and tennis. Two independent reviewers graded each study on the Physiotherapy Evidence Database (PEDro) scale. Seven of 89 research articles met all inclusion criteria and a minimum score of 4 out of 10 on the PEDro scale. After an extensive and critical review of the available research on whole-body cooling for the treatment of exertional hyperthermia, we concluded that ice-water immersion provides the most efficient cooling. Further research comparing whole-body cooling modalities is needed to identify other acceptable means. When ice-water immersion is not possible, continual dousing with water combined with fanning the patient is an alternative method until more advanced cooling means can be used. Until future investigators identify other acceptable whole-body cooling modalities for exercise-induced hyperthermia, ice-water immersion and cold-water immersion are the methods proven to have the fastest cooling rates.

Exercise-Induced Rhabdomyolysis and Stress-Induced Malignant Hyperthermia Events, Association with Malignant Hyperthermia Susceptibility, and RYR1 Gene Sequence Variations

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Antonella Carsana

2013-01-01

Full Text Available Exertional rhabdomyolysis (ER and stress-induced malignant hyperthermia (MH events are syndromes that primarily afflict military recruits in basic training and athletes. Events similar to those occurring in ER and in stress-induced MH events are triggered after exposure to anesthetic agents in MH-susceptible (MHS patients. MH is an autosomal dominant hypermetabolic condition that occurs in genetically predisposed subjects during general anesthesia, induced by commonly used volatile anesthetics and/or the neuromuscular blocking agent succinylcholine. Triggering agents cause an altered intracellular calcium regulation. Mutations in RYR1 gene have been found in about 70% of MH families. The RYR1 gene encodes the skeletal muscle calcium release channel of the sarcoplasmic reticulum, commonly known as ryanodine receptor type 1 (RYR1. The present work reviews the documented cases of ER or of stress-induced MH events in which RYR1 sequence variations, associated or possibly associated to MHS status, have been identified.

Synthesis and hyperthermia property of hydroxyapatite-ferrite hybrid particles by ultrasonic spray pyrolysis

International Nuclear Information System (INIS)

Inukai, Akihiro; Sakamoto, Naonori; Aono, Hiromichi; Sakurai, Osamu; Shinozaki, Kazuo; Suzuki, Hisao; Wakiya, Naoki

2011-01-01

Biocompatible hybrid particles composed of hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 , HAp) and ferrite (γ-Fe 2 O 3 and Fe 3 O 4 ) were synthesized using a two-step procedure. First, the ferrite particles were synthesized by co-precipitation. Second, the suspension, which was composed of ferrite particles by a co-precipitation method, Ca(NO 3 ) 2 , and H 3 PO 4 aqueous solution with surfactant, was nebulized into mist ultrasonically. Then the mist was pyrolyzed at 1000 o C to synthesize HAp-ferrite hybrid particles. The molar ratio of Fe ion and HAp was (Fe 2+ and Fe 3+ )/HAp=6. The synthesized hybrid particle was round and dimpled, and the average diameter of a secondary particle was 740 nm. The cross section of the synthesized hybrid particles revealed two phases: HAp and ferrite. The ferrite was coated with HAp. The synthesized hybrid particles show a saturation magnetization of 11.8 emu/g. The net saturation magnetization of the ferrite component was calculated as 32.5 emu/g. The temperature increase in the AC-magnetic field (370 kHz, 1.77 kA/m) was 9 o C with 3.4 g (the ferrite component was 1.0 g). These results show that synthesized hybrid particles are biocompatible and might be useful for magnetic transport and hyperthermia studies. - Research Highlights: → Biocompatible hybrid particles composed of hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 , HAp) and ferrite (γ-Fe 2 O 3 and Fe 3 O 4 ) were synthesized using a two-step synthesis, which is comprised of co-precipitation and ultrasonic spray pyrolysis. → Cross sectional TEM observation and X-ray diffraction revealed that synthesized hybrid particles showed two phases (HAp and ferrite), and the ferrite was coated with HAp. → The saturation magnetization of ferrite in the HAp-ferrite hybrid was 32.49 emu/g. → The increased temperature in the AC-magnetic field (370 kHz, 1.77 kA/m) was 9 o C with 3.4 g (the ferrite component was 1.0 g).

PET measurements of hyperthermia-induced suppression of protein synthesis in tumors in relation to effects on tumor growth

International Nuclear Information System (INIS)

Daemen, B.J.; Elsinga, P.H.; Mooibroek, J.; Paans, A.M.; Wieringa, A.R.; Konings, A.W.; Vaalburg, W.

1991-01-01

Hyperthermia-induced metabolic changes in tumor tissue have been monitored by PET. Uptake of L-[1-11C]tyrosine in rhabdomyosarcoma tissue of Wag/Rij rats was dose-dependently reduced after local hyperthermia treatment at 42, 45, or 47 degrees C. Tumor blood flow, as measured by PET with 13NH3, appeared to be unchanged. The L-[1-11C]tyrosine uptake data were compared to uptake data of L-[1-14C]tyrosine and with data on the incorporation of L-[1-14C]tyrosine into tumor proteins. After intravenous injection, the 14C data were obtained from dissected tumor tissue. Heat-induced inhibition of the incorporation of L-[1-14C]tyrosine into tumor proteins tallied with the L-[1-11C]tyrosine uptake data. Heat-induced inhibition of amino acid uptake in the tumor correlated well with regression of tumor growth. It is concluded that PET using L-[1-11C]tyrosine is eligible for monitoring the effect of hyperthermia on tumor growth

Non-Invasive Radiofrequency-Induced Targeted Hyperthermia for the Treatment of Hepatocellular Carcinoma

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Mustafa Raoof

2011-01-01

Full Text Available Targeted biological therapies for hepatocellular cancer have shown minimal improvements in median survival. Multiple pathways to oncogenesis leading to rapid development of resistance to such therapies is a concern. Non-invasive radiofrequency field-induced targeted hyperthermia using nanoparticles is a radical departure from conventional modalities. In this paper we underscore the need for innovative strategies for the treatment of hepatocellular cancer, describe the central paradigm of targeted hyperthermia using non-invasive electromagnetic energy, review the process of characterization and modification of nanoparticles for the task, and summarize data from cell-based and animal-based models of hepatocellular cancer treated with non-invasive RF energy. Finally, future strategies and challenges in bringing this modality from bench to clinic are discussed.

Dopamine D(3) receptors contribute to methamphetamine-induced alterations in dopaminergic neuronal function: role of hyperthermia.

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Baladi, Michelle G; Newman, Amy H; Nielsen, Shannon M; Hanson, Glen R; Fleckenstein, Annette E

2014-06-05

Methamphetamine administration causes long-term deficits to dopaminergic systems that, in humans, are thought to be associated with motor slowing and memory impairment. Methamphetamine interacts with the dopamine transporter (DAT) and increases extracellular concentrations of dopamine that, in turn, binds to a number of dopamine receptor subtypes. Although the relative contribution of each receptor subtype to the effects of methamphetamine is not fully known, non-selective dopamine D2/D3 receptor antagonists can attenuate methamphetamine-induced changes to dopamine systems. The present study extended these findings by testing the role of the dopamine D3 receptor subtype in mediating the long-term dopaminergic, and for comparison serotonergic, deficits caused by methamphetamine. Results indicate that the dopamine D3 receptor selective antagonist, PG01037, attenuated methamphetamine-induced decreases in striatal DAT, but not hippocampal serotonin (5HT) transporter (SERT), function, as assessed 7 days after treatment. However, PG01037 also attenuated methamphetamine-induced hyperthermia. When methamphetamine-induced hyperthermia was maintained by treating rats in a warm ambient environment, PG01037 failed to attenuate the effects of methamphetamine on DAT uptake. Furthermore, PG01037 did not attenuate methamphetamine-induced decreases in dopamine and 5HT content. Taken together, the present study demonstrates that dopamine D3 receptors mediate, in part, the long-term deficits in DAT function caused by methamphetamine, and that this effect likely involves an attenuation of methamphetamine-induced hyperthermia. Copyright © 2014 Elsevier B.V. All rights reserved.

Dopamine D3 receptors contribute to methamphetamine-induced alterations in dopaminergic neuronal function: Role of hyperthermia

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Baladi, Michelle G.; Newman, Amy H.; Nielsen, Shannon M.; Hanson, Glen R.; Fleckenstein, Annette E.

2014-01-01

Methamphetamine administration causes long-term deficits to dopaminergic systems that, in humans, are thought to be associated with motor slowing and memory impairment. Methamphetamine interacts with the dopamine transporter (DAT) and increases extracellular concentrations of dopamine that, in turn, binds to a number of dopamine receptor subtypes. Although the relative contribution of each receptor subtype to the effects of methamphetamine is not fully known, non-selective dopamine D2/D3 receptor antagonists can attenuate methamphetamine-induced changes to dopamine systems. The present study extended these findings by testing the role of the dopamine D3 receptor subtype in mediating the long-term dopaminergic, and for comparison serotonergic, deficits caused by methamphetamine. Results indicate that the dopamine D3 receptor selective antagonist, PG01037, attenuated methamphetamine-induced decreases in striatal DAT, but not hippocampal serotonin (5HT) transporter (SERT), function, as assessed 7 days after treatment. However, PG01037 also attenuated methamphetamine-induced hyperthermia. When methamphetamine-induced hyperthermia was maintained by treating rats in a warm ambient environment, PG01037 failed to attenuate the effects of methamphetamine on DAT uptake. Furthermore, PG01037 did not attenuate methamphetamine-induced decreases in dopamine and 5HT content. Taken together, the present study demonstrates that dopamine D3 receptors mediate, in part, the long-term deficits in DAT function caused by methamphetamine, and that this effect likely involves an attenuation of methamphetamine-induced hyperthermia. PMID:24685638

Neuronal Rat Brain Damage Caused by Endogenous and Exogenous Hyperthermia

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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

High doses of L-naloxone but neither D-naloxone nor beta-funaltrexamine prevent hyperthermia-induced seizures in rat pups.

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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.

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

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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.

[Destruction of synovial pannus of antigen-induced arthritis by ultrasonic cavitation in rabbits].

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Zhang, Ling-yan; Qiu, Li; Wang, Lei; Lin, Ling; Wen, Xiao-rong

2011-11-01

To optimize the conditions of ultrasonic irradiation and microbubble of ultrasound cavitation on destruction of synovial pannus of antigen-induced arthritis (AIA) in rabbits. Antigen-induced arthritis was successfully induced on bilateral knee joints of 85 rabbits. Each 10 AIA rabbits were divided into two groups to compare various peak negative pressures, different ultrasonic pulse durations, various pulse repetition frequencies, different irradiance duration, different dosages of microbubble contrast agents, different ultrasonic irradiance times. With intravenous infusion of Sonovue to the rabbits, ultrasonic irradiance was performed on the right knee joint using the above condition of ultrasound cavitation. At the day 1 after ultrasonic irradiance, MRI and pathological examination were employed to evaluate the optimal conditions. The optimal parameters and conditions for ultrasonic irradiance included intermittent ultrasonic application (in 6 s intervals), 0.6 mL/kg of microbubble contrast agent, 4.6 MPa of ultrasonic peak negative pressure, 100 cycles of pulse duration, 50 Hz of pulse repetition frequency, 5 min of ultrasonic duration, 0.6 mL/kg of dosages of microbubble contrast agents and multi-sessional ultrasonic irradiance. After the ultrasonic irradiance, the thickness of right knee synovium measured by MRI was thinner than that of left knee and synovial necrosis was confirmed by the pathological finding. Under optimal ultrasonic irradiation and microbubble conditions, ultrasonic cavitation could destroy synovial pannus of AIA in rabbits.

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)

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

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

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Gang Sun

executive control reaction time. CONCLUSIONS/SIGNIFICANCE: We first identified the hyperthermia-induced altered functional connectivity patterns. The changes in the functional connectivity network might be a possible explanation for the cognitive performance and work behavior alteration.

Chemotherapy and Radiofrequency-Induced Mild Hyperthermia Combined Treatment of Orthotopic Pancreatic Ductal Adenocarcinoma Xenografts.

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Krzykawska-Serda, Martyna; Agha, Mahdi S; Ho, Jason Chak-Shing; Ware, Matthew J; Law, Justin J; Newton, Jared M; Nguyen, Lam; Curley, Steven A; Corr, Stuart J

2018-04-02

Patients with pancreatic ductal adenocarcinomas (PDAC) have one of the poorest survival rates of all cancers. The main reason for this is related to the unique tumor stroma and poor vascularization of PDAC. As a consequence, chemotherapeutic drugs, such as nab-paclitaxel and gemcitabine, cannot efficiently penetrate into the tumor tissue. Non-invasive radiofrequency (RF) mild hyperthermia treatment was proposed as a synergistic therapy to enhance drug uptake into the tumor by increasing tumor vascular inflow and perfusion, thus, increasing the effect of chemotherapy. RF-induced hyperthermia is a safer and non-invasive technique of tumor heating compared to conventional contact heating procedures. In this study, we investigated the short- and long-term effects (~20 days and 65 days, respectively) of combination chemotherapy and RF hyperthermia in an orthotopic PDAC model in mice. The benefit of nab-paclitaxel and gemcitabine treatment was confirmed in mice; however, the effect of treatment was statistically insignificant in comparison to saline treated mice during long-term observation. The benefit of RF was minimal in the short-term and completely insignificant during long-term observation. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

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.)

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

Induced apoptosis by mild hyperthermia occurs via telomerase inhibition on the three human myeloid leukemia cell lines: TF-1, K562, and HL-60.

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Deezagi, Abdolkhaleg; Manteghi, Sanaz; Khosravani, Pardis; Vaseli-Hagh, Neda; Soheili, Zahra-Soheila

2009-09-01

The purpose of this research was to understand the effect of hyperthermia on the telomerase activity in human leukemic cell lines (HL-60, K562, and TF-1). The cells were treated by hyperthermia at the range of 41-44 degrees C for 120 min and incubated for 96 h. Then telomerase activity, cell proliferation, and apoptosis were assessed. The results indicated that hyperthermia significantly induced apoptosis on the cells. The cells exhibited pre-apoptotic pattern at 41 and 42 degrees C at 60-120 min and apoptotic pattern at 43 and 44 degrees C over 30 min after hyperthermia. Telomerase activity (that was assayed immediately after hyperthermia) was stable at 41-42 degrees C for 60 min but decreased to 35-40% at 120 min. However, at severe hyperthermia (43-44 degrees C) telomerase activity was decreased in a time- and dose-dependent manner. Following hyperthermia (41-44 degrees C up to 120 min), the cells were incubated for 96 h. In these conditions, the telomerase activity was decreased by about 60-80% in comparison with that untreated control cells.

MDMA, Methylone, and MDPV: Drug-Induced Brain Hyperthermia and Its Modulation by Activity State and Environment.

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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

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

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

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

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

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)

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...

Ultrasonic transducer design for uniform insonation

International Nuclear Information System (INIS)

Harrison, G.H.; Balcer-Kubiczek, E.K.; McCulloch, D.

1984-01-01

Techniques used in transducer development for acoustical imaging have been evaluated for the purpose of producing broad, uniform ultrasonic fields from planar radiators. Such fields should be useful in hyperthermia, physical therapy, and ultrasonic bioeffects studies. Fourier inversion of the circ function yielded a source velocity distribution proportional to (P/r) exp ((-ik/2Z) (2Z/sup 2/+r/sup 2/)) J/sub 1/(krP/Z), where r is the radial source coordinate, k is the wave number, and P is the desired radius of uniform insonation at a depth Z in water. This source distribution can be truncated without significantly degrading the solution. A simpler solution consists of exponentially shading the edge of an otherwise uniformly excited disk transducer. This approach was successfully approximated experimentally

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

Effects of hyperthermia and X-irradiation on mouse stromal tissue

International Nuclear Information System (INIS)

Wondergem, J.; Haveman, J.

1986-01-01

The sensitivity of normal stroma to heat, irradiation and heat combined with irradiation, was studied using the tumour bed effect (TBE) assay. Irradiation before implantation led to a TBE, dose dependent below 15 Gy, but remaining relatively constant above. The interval (0-90 days) between irradiation and tumour implantation did not influence the magnitude of the TBE. Hyperthermia with large heat doses (45-60 min at 44 0 C) before implantation may lead to a TBE. The interval between hyperthermia and tumour implantation was very important. Results showed that the recovery from heat-induced stromal damage is very rapid. When the interval between hyperthermia and tumour implantation was 10 days or longer, no TBE could be observed. Irradiation combined with large heat doses (30-60 min at 44 0 C) decreased the radiation-induced TBE. The combination of irradiation with mild heat treatments (15 min at 44 0 C) could lead to a larger TBE then after irradiation alone. When hyperthermia was given prior to irradiation, the interval between heat and irradiation proved to be very important. With large intervals (21 days or longer), TBE values were about the same as with irradiation alone. When heat was given after irradiation, irradiation-induced TBE was always reduced. (UK)

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)

The protective role of nitric oxide and nitric oxide synthases in whole-body hyperthermia-induced hepatic injury in rats.

Science.gov (United States)

Chen, Chao-Fuh; Wang, David; Leu, Fur-Jiang; Chen, Hsing I

2012-01-01

The present study was designed to elucidate the role of endothelial nitric oxide (NO) synthase (eNOS), inducible NOS (iNOS)-derived NO and heat-shock protein (Hsp70) in a rat model of whole-body hyperthermia (WBH)-induced liver injury. Real-time polymerase chain reaction, immunohistochemistry and western blot were used to observe the mRNA and protein expression of eNOS, iNOS and Hsp70. Rats were exposed to hyperthermia by immersion for 60 min at a conscious state in a water bath maintained at 41°C. Plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were used to assess liver injury 15 h after the hyperthermia challenge. Nitrosative and oxidative mediators, particularly NO and hydroxyl radical were measured. Plasma AST, ALT, hydroxyl radical, and NO were significantly increased after WBH. There were 4.14 ± 0.42, 2.82 ± 0.34 and 2.91 ± 0.16-fold increases in the mRNA expression of eNOS, iNOS and Hsp70. Immunohistochemistry and western blot showed up-regulation of eNOS, iNOS and Hsp70 protein. An eNOS inhibitor (N(ω)-nitro-L-arginine methyl ester (L-NAME)), or an iNOS inhibitor (aminoguanidine (AG)), significantly aggravated the liver injury. On the contrary, administration of NO precursor, L-arginine (L-ARG), attenuated the liver injury. Hsp70 inhibitor quercetin reduced Hsp70, while aggravating the WBH-induced hepatic changes. WBH induces increases in eNOS, iNOS and Hsp70 expression with increase in NO release. The deleterious effects of L-NAME and AG and the protective effects of L-ARG and Hsp70 inhibitor on the liver function and pathology suggest that NO and heat shock protein play a beneficial role in the WBH-induced hepatic injury.

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

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).

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

Experimental febrile seizures are precipitated by a hyperthermia-induced respiratory alkalosis.

Science.gov (United States)

Schuchmann, Sebastian; Schmitz, Dietmar; Rivera, Claudio; Vanhatalo, Sampsa; Salmen, Benedikt; Mackie, Ken; Sipilä, Sampsa T; Voipio, Juha; Kaila, Kai

2006-07-01

Febrile seizures are frequent during early childhood, and prolonged (complex) febrile seizures are associated with an increased susceptibility to temporal lobe epilepsy. The pathophysiological consequences of febrile seizures have been extensively studied in rat pups exposed to hyperthermia. The mechanisms that trigger these seizures are unknown, however. A rise in brain pH is known to enhance neuronal excitability. Here we show that hyperthermia causes respiratory alkalosis in the immature brain, with a threshold of 0.2-0.3 pH units for seizure induction. Suppressing alkalosis with 5% ambient CO2 abolished seizures within 20 s. CO2 also prevented two long-term effects of hyperthermic seizures in the hippocampus: the upregulation of the I(h) current and the upregulation of CB1 receptor expression. The effects of hyperthermia were closely mimicked by intraperitoneal injection of bicarbonate. Our work indicates a mechanism for triggering hyperthermic seizures and suggests new strategies in the research and therapy of fever-related epileptic syndromes.

Simultaneous hyperthermia and doxorubicin delivery from polymer-coated magnetite nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Iglesias, G.R., E-mail: iglesias@ugr.es [Department of Applied Physics, University of Granada, Granada 18071 (Spain); Delgado, A.V.; González-Caballero, F. [Department of Applied Physics, University of Granada, Granada 18071 (Spain); Ramos-Tejada, M.M. [Department of Physics, University of Jaén, Linares 23700 (Spain)

2017-06-01

In this work, the hyperthermia response, (i.e., heating induced by an externally applied alternating magnetic field) and the simultaneous release of an anti-cancer drug (doxorubicin) by polymer-coated magnetite nanoparticles have been investigated. After describing the setup for hyperthermia measurements in suspensions of magnetic nanoparticles, the hyperthermia (represented by the rate of suspension heating and, ultimately, by the specific absorption rate or SAR) of magnetite nanoparticles (both bare and polymer-coated as drug nanocarriers) is discussed. The effect of the applied ac magnetic field on doxorubicin release is also studied, and it is concluded that the field does not interfere with the release process, demonstrating the double functionality of the investigated particles. - Highlights: • Magnetite NPs coated with polymers are used for drug delivery and hyperthermia. • The SAR of polyelectrolyte-coated NPs is larger because of their improved stability. • The antitumor drug doxorubicin is adsorbed on the coated particles. • The release rate of the drug is not affected by the ac magnetic field used in hyperthermia.

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 ...

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

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

Contributions of different modes of TRPV1 activation to TRPV1 antagonist-induced hyperthermia.

Science.gov (United States)

Garami, Andras; Shimansky, Yury P; Pakai, Eszter; Oliveira, Daniela L; Gavva, Narender R; Romanovsky, Andrej A

2010-01-27

Transient receptor potential vanilloid-1 (TRPV1) antagonists are widely viewed as next-generation pain therapeutics. However, these compounds cause hyperthermia, a serious side effect. TRPV1 antagonists differentially block three modes of TRPV1 activation: by heat, protons, and chemical ligands (e.g., capsaicin). We asked what combination of potencies in these three modes of TRPV1 activation corresponds to the lowest potency of a TRPV1 antagonist to cause hyperthermia. We studied hyperthermic responses of rats, mice, and guinea pigs to eight TRPV1 antagonists with different pharmacological profiles and used mathematical modeling to find a relative contribution of the blockade of each activation mode to the development of hyperthermia. We found that the hyperthermic effect has the highest sensitivity to the extent of TRPV1 blockade in the proton mode (0.43 to 0.65) with no to moderate sensitivity in the capsaicin mode (-0.01 to 0.34) and no sensitivity in the heat mode (0.00 to 0.01). We conclude that hyperthermia-free TRPV1 antagonists do not block TRPV1 activation by protons, even if they are potent blockers of the heat mode, and that decreasing the potency to block the capsaicin mode may further decrease the potency to cause hyperthermia.

Acoustic streaming induced by an ultrasonically oscillating endodontic file

NARCIS (Netherlands)

Verhaagen, B.; Boutsioukis, C.; van der Sluis, L.W.M.; Versluis, M.

2014-01-01

Ultrasonically activated irrigation is an advanced dental technique for irrigation of the root canal system during a root canal treatment. The basic cleaning mechanism is a result of acoustic streaming induced by an oscillating file, leading to mixing of the irrigant and pressure and shear stresses

Acoustic streaming induced by an ultrasonically oscillating endodontic file

NARCIS (Netherlands)

Verhaagen, B.; Boutsioukis, C.; van der Sluis, L. W. M.; Versluis, M.

Ultrasonically activated irrigation is an advanced dental technique for irrigation of the root canal system during a root canal treatment. The basic cleaning mechanism is a result of acoustic streaming induced by an oscillating file, leading to mixing of the irrigant and pressure and shear stresses

Ultrasonic enhancement of drug penetration in solid tumors

Directory of Open Access Journals (Sweden)

Chun-yen eLai

2013-08-01

Full Text Available Increasing the penetration of drugs within solid tumors can be accomplished through multiple ultrasound-mediated mechanisms. The application of ultrasound can directly change the structure or physiology of tissues or can induce changes in a drug or vehicle in order to enhance delivery and efficacy. With each ultrasonic pulse, a fraction of the energy in the propagating wave is absorbed by tissue and results in local heating. When ultrasound is applied to achieve mild hyperthermia, the thermal effects are associated with an increase in perfusion or the release of a drug from a temperature-sensitive vehicle. Higher ultrasound intensities locally ablate tissue and result in increased drug accumulation surrounding the ablated region of interest. Further, the mechanical displacement induced by the ultrasound pulse can result in the nucleation, growth and collapse of gas bubbles. As a result of such cavitation, the permeability of a vessel wall or cell membrane can be increased. Finally, the radiation pressure of the propagating pulse can translate particles or tissues. In this perspective, we will review recent progress in ultrasound-mediated tumor delivery and the opportunities for clinical translation.

Effect of hyperthermia in combination with radiation therapy in a rat glioma model

International Nuclear Information System (INIS)

Tamura, Masaru; Zama, Akira; Kunimine, Hideo; Tamaki, Yoshio; Niibe, Hideo

1988-01-01

Rat glioma model was used to evaluate the effect of hyperthermia with and without radiation therapy. The animal model was induced by left frontal burr hole opening and inoculation of a small piece of G-XII glioma tissue to 6- to 8-week-old rats. The therapeutical experiments were given 10 - 14 days after inoculation of the tumor. Interstitial heating at 44 and 45 deg C at the surface of the inserting probe using 2450 MHz microwave was delivered for 30 minutes. Deep X-ray whole head irradiation of 800 R using Stabilipan 2 (Siemens) was given just after the hyperthermia therapy. The survival of treated animals of hyperthermia, radiation, and combination of hyperthermia and radiation was significantly superior to that of non-treated control group. There was no significant difference of survival among the treated groups, though median survival was longest in the group of combination therapy of hyperthermia and radiation. Large tumors developed at the time of death in all the control and the treated animals. Histological examination showed some tendencies of macrophage infiltration in tumor tissue of hyperthermia therapy. (author)

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.

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.

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

Laser induced ultrasonic phased array using full matrix capture data acquisition and total focusing method.

Science.gov (United States)

Stratoudaki, Theodosia; Clark, Matt; Wilcox, Paul D

2016-09-19

Laser ultrasonics is a technique where lasers are employed to generate and detect ultrasound. A data collection method (full matrix capture) and a post processing imaging algorithm, the total focusing method, both developed for ultrasonic arrays, are modified and used in order to enhance the capabilities of laser ultrasonics for nondestructive testing by improving defect detectability and increasing spatial resolution. In this way, a laser induced ultrasonic phased array is synthesized. A model is developed and compared with experimental results from aluminum samples with side drilled holes and slots at depths of 5 - 20 mm from the surface.

Hyperthermia enhances radiosensitivity of colorectal cancer cells through ROS inducing autophagic cell death.

Science.gov (United States)

Ba, Ming-Chen; Long, Hui; Wang, Shuai; Wu, Yin-Bing; Zhang, Bo-Huo; Yan, Zhao-Fei; Yu, Fei-Hong; Cui, Shu-Zhong

2018-04-01

Hyperthermia (HT) enhances the anti-cancer effects of radiotherapy (RT), but the precise biochemical mechanisms involved are unclear. This study was aim to investigate if mild HT sensitizes colorectal cancer cells to RT through reactive oxygen species (ROS)-inducing autophagic cell death in a mice model of HCT116 human colorectal cancer. HCT116 mice model were randomly divided into five groups: mock group, hyperthermia group (HT), radiotherapy group (RT), HT + RT group, and HT + RT +N-acetyl L-cysteine (NAC) group (HT + CT + NAC). After four weeks of treatment, cancer growth inhibition, rate and mitochondrial membrane potential were measured with MTT and JC-1 assays, respectively, while ROS were estimated fluorimetrically. The relationship of these parameters to expressions of autophagy-related genes Beclin1, LC3B, and mTOR was analyzed. Gene expression was measured by Real-Time polymerase chain reaction (RT-PCR). There were significant increases in ROS levels and mitochondrial membrane potential in the HT + RT group. ROS levels in the HT + RT group increased more significantly than in any other group. In contrast, ROS levels in the HT + RT + NAC group were significantly decreased relative to the HT + RT group. The number of autophagic bodies in HT + RT group was higher than that of mock group. There were significant increases in the expression of Beclin1 and LC3B genes, while mTOR expression was significantly decreased in the HT + CT group. Treatment with NAC reversed the pattern of these changes. These results indicate that HT enhances the radiosensitivity of colorectal cancer cells to RT through ROS inducing autophagic cell death. © 2017 Wiley Periodicals, Inc.

Effects of hyperthermia on the normal liver using scintigraphic methods. Functional changes of the rabbit whole-liver by local hyperthermia

International Nuclear Information System (INIS)

Ryu, Kiyotaka; Shinotsuka, Akira; Takenaka, Hiroki; Hirono, Yoshisada

1995-01-01

An experimental study was conducted to investigate effect of hyperthermia to the liver in rabbits. The whole liver was heated at 43degC for 30 min by a RF capacitive heating device, and subsequent changes were observed by scintigraphy using 99m Tc-EHIDA and 99m Tc-Sn-colloid. The excretory ratio (Ke value) of 99m Tc-EHIDA and the uptake ratio (K value) of 99m Tc-Sn-colloid were measured to estimate hyperthermia induced hepatic injury for a month. Blood chemistry analysis was also conducted during this period. Also, the uptake of 3 H-methyl-thymidine into the DNA of hepatocyted was assayed 2 and 5 days after heating. Concurrently, histopathological changes were observed. The Ke value showed a transient increase and returned to the level prior to heating after approximately one week. A distinct increase in GPT was observed. The uptake of 3 H-methyl-thymidine showed a marked rise 2 days after hyperthermia, which demonstrated regeneration of the previously damaged hepatocytes. Pathologically, overall liver congestion and hepatocytes necrosis were noted. Also, both enlargement of the nuclei and binuclear hepatocytes were present, pathologically proving hepatocytes regeneration. The K value showed a transient decrease, showing that the reticuloendothelial function and blood flow of the liver were temporarily reduced. These results indicate the whole liver function damaged by hyperthermia is reversible. (author)

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)

Turbulence enhancement by ultrasonically induced gaseous cavitation in the CO2 saturated water

International Nuclear Information System (INIS)

Lee, Seung Youp; Choi, Young Don

2002-01-01

Recent primary concern for the design of high performance heat exchanger and highly integrated electronic equipment is to develop an active and creative technologies which enhance the heat transfer without obstructing the coolant flows. In this study, we found through the LDV measurement that the gaseous cavitation induced by ultrasonic vibration applied to the CO 2 saturated water in the square cross-sectioned straight duct flow enhances the turbulence much more than the case of non-ultrasonic or normal ultrasonic conditions without gaseous cavitation does. We also found that gaseous cavitation can enhance effectively the turbulent heat transfer between the heating surfaces and coolants by destructing the viscous sublayer

The effects of isatin (indole-2, 3-dione on pituitary adenylate cyclase-activating polypeptide-induced hyperthermia in rats

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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.

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

Synchronous ultrasonic Doppler imaging of magnetic microparticles in biological tissues

Energy Technology Data Exchange (ETDEWEB)

Pyshnyi, Michael Ph. [Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin St. 4, Moscow 119991 (Russian Federation); Kuznetsov, Oleg A. [Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin St. 4, Moscow 119991 (Russian Federation)], E-mail: kuznetsov_oa@yahoo.com; Pyshnaya, Svetlana V.; Nechitailo, Galina S.; Kuznetsov, Anatoly A. [Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin St. 4, Moscow 119991 (Russian Federation)

2009-05-15

We considered applicability of acoustic imaging technology for the detection of magnetic microparticles and nanoparticles inside soft biological tissues. Such particles are widely used for magnetically targeted drug delivery and magnetic hyperthermia. We developed a new method of ultrasonic synchronous tissue Doppler imaging with magnetic modulation for in vitro and in vivo detection and visualization of magnetic ultradisperse objects in soft tissues. Prototype hardware with appropriate software was produced and the method was successfully tested on magnetic microparticles injected into an excised pig liver.

Synchronous ultrasonic Doppler imaging of magnetic microparticles in biological tissues

International Nuclear Information System (INIS)

Pyshnyi, Michael Ph.; Kuznetsov, Oleg A.; Pyshnaya, Svetlana V.; Nechitailo, Galina S.; Kuznetsov, Anatoly A.

2009-01-01

We considered applicability of acoustic imaging technology for the detection of magnetic microparticles and nanoparticles inside soft biological tissues. Such particles are widely used for magnetically targeted drug delivery and magnetic hyperthermia. We developed a new method of ultrasonic synchronous tissue Doppler imaging with magnetic modulation for in vitro and in vivo detection and visualization of magnetic ultradisperse objects in soft tissues. Prototype hardware with appropriate software was produced and the method was successfully tested on magnetic microparticles injected into an excised pig liver.

Ablation of synovial pannus using microbubble-mediated ultrasonic cavitation in antigen-induced arthritis in rabbits.

Science.gov (United States)

Qiu, Li; Jiang, Yong; Zhang, Lingyan; Wang, Lei; Luo, Yan

2012-12-01

To investigate the ablative effectiveness of microbubble-mediated ultrasonic cavitation for treating synovial pannus and to determine a potential mechanism using the antigen-induced arthritis model (AIA). Ultrasonic ablation was performed on the knee joints of AIA rabbits using optimal ultrasonic ablative parameters. Rabbits with antigen-induced arthritis were randomly assigned to 4 groups: (1) the ultrasound (US) + microbubble group; (2) the US only group; (3) the microbubble only group, and (4) the control group. At 1 h and 14 days after the first ablation, contrast-enhanced ultrasonography (CEUS) monitoring and pathology synovitis score were used to evaluate the therapeutic effects. Synovial necrosis and microvascular changes were also measured. After the ablation treatment, the thickness of synovium and parameters of time intensity curve including derived peak intensity and area under curve were measured using CEUS, and the pathology synovitis score in the ultrasound + microbubble group was significantly lower than that found in the remaining groups. No damage was observed in the surrounding normal tissues. The mechanism underlying the ultrasonic ablation was related to microthrombosis and microvascular rupture that resulted in synovial necrosis. The results suggest that microbubble-mediated ultrasonic cavitation should be applied as a non-invasive strategy for the treatment of synovial pannus in arthritis under optimal conditions.

Evaluation of ferromagnetic fluids and suspensions for the site-specific radiofrequency-induced hyperthermia of MX11 sarcoma cells in vitro

Energy Technology Data Exchange (ETDEWEB)

Brusentsov, Nikolai A.; Gogosov, V.V.; Brusentsova, T.N.; Sergeev, A.V.; Jurchenko, N.Y.; Kuznetsov, Anatoly A.; Kuznetsov, Oleg A. E-mail: oleg@louisiana.edu; Shumakov, L.I

2001-07-01

Seventeen different ferromagnetic fluids and suspensions were prepared and evaluated for application in radiofrequency-induced hyperthermia. Specific power absorption rates were measured at 0.88 MHz to range from 0 to 240 W per gram of iron for different preparations. Survival of MX11 cells mixed with ferrofluids and subjected to radiofrequency was much lower than with RF without ferrofluid or ferrofluid alone.

Evaluation of ferromagnetic fluids and suspensions for the site-specific radiofrequency-induced hyperthermia of MX11 sarcoma cells in vitro

International Nuclear Information System (INIS)

Brusentsov, Nikolai A.; Gogosov, V.V.; Brusentsova, T.N.; Sergeev, A.V.; Jurchenko, N.Y.; Kuznetsov, Anatoly A.; Kuznetsov, Oleg A.; Shumakov, L.I.

2001-01-01

Seventeen different ferromagnetic fluids and suspensions were prepared and evaluated for application in radiofrequency-induced hyperthermia. Specific power absorption rates were measured at 0.88 MHz to range from 0 to 240 W per gram of iron for different preparations. Survival of MX11 cells mixed with ferrofluids and subjected to radiofrequency was much lower than with RF without ferrofluid or ferrofluid alone

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).

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)

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

31P-MRS study for the assessment of tumor response after radiotherapy and/or hyperthermia

International Nuclear Information System (INIS)

Kimura, Hirohiko; Itho, Satoshi; Nakatsugawa, Sigekazu; Maeda, Masayuki; Iwasaki, Toshiko; Yamamoto, Kazutaka; Ishii, Yasushi

1992-01-01

The metabolic changes of human lung cancer implanted in nude mice were studied by the use of in vivo 31 P nuclear magnetic resonance spectroscopy ( 31 P-MRS) after radiotherapy, hyperthermia or the combined therapy of radiation and hyperthermia. 31 P-MRS of the tumors showed increased Pi/β-NTP ratio and acidic pH value on 1 day after hyperthermia, that indicated metabolic decline caused by hyperthermia. On the other hand, lower Pi/β-NTP ratios during 3 to 10 days after irradiation suggested metabolic activation of the tumors. In the tumors treated with the combined therapy, 31 P-MRS revealed increase of Pi/β-NTP ratio within 1 day and its decrease subsequent 6 to 10 days after treatment, that indicated additive bi-phasic changes induced by radiation and hyperthermia, respectively. Since Pi/β-NTP ratio had significant correlation to the tumor blood perfusion measured by hydrogen gas clearance studies, these bi-phasic changes were considered to correspond to two different physiological states, namely, ischemic and reperfused states. 31 P-MRS obtained from tumors could be useful to asses the physiological consequence following radiation, hyperthermia or the combined therapy. (author)

Comparison of microwave and magnetic nanoparticle hyperthermia radiosensitization in murine breast tumors

Science.gov (United States)

Giustini, Andrew J.; Petryk, Alicia A.; Hoopes, Paul J.

2011-03-01

Hyperthermia has been shown to be an effective radiosensitizer. Its utility as a clinical modality has been limited by a minimally selective tumor sensitivity and the inability to be delivered in a tumor-specific manner. Recent in vivo studies (rodent and human) have shown that cancer cell-specific cytotoxicity can be effectively and safely delivered via iron oxide magnetic nanoparticles (mNP) and an appropriately matched noninvasive alternating magnetic field (AMF). To explore the tumor radiosensitization potential of mNP hyperthermia we used a syngeneic mouse breast cancer model, dextran-coated 110 nm hydrodynamic diameter mNP and a 169 kHz / 450 Oe (35.8 kA/m) AMF. Intradermally implanted (flank) tumors (150 +/- 40 mm3) were treated by injection of 0.04 ml mNP (7.5 mg Fe) / cm3 into the tumor and an AMF (35.8 kA/m and 169 kHz) exposure necessary to achieve a CEM (cumulative equivalent minute) thermal dose of 60 (CEM 60). Tumors were treated with mNP hyperthermia (CEM 60), radiation alone (15 Gy, single dose) and in combination. Compared to the radiation and heat alone treatments, the combined treatment resulted in a greater than two-fold increase in tumor regrowth tripling time (tumor treatment efficacy). None of the treatments resulted in significant normal tissue toxicity or morbidity. Studies were also conducted to compare the radiosensitization effect of mNP hyperthermia with that of microwave-induced hyperthermia. The effects of incubation of nanoparticles within tumors (to allow nanoparticles to be endocytosed) before application of AMF and radiation were determined. This preliminary information suggests cancer cell specific hyperthermia (i.e. antibody-directed or anatomically-directed mNP) is capable of providing significantly greater radiosensitization / therapeutic ratio enhancement than other forms of hyperthermia delivery.

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

Whole-body fluid distribution in humans during dehydration and recovery, before and after humid-heat acclimation induced using controlled hyperthermia.

Science.gov (United States)

Patterson, M J; Stocks, J M; Taylor, N A S

2014-04-01

This experiment was designed to test the hypothesis that the plasma volume is not selectively defended during exercise- and heat-induced dehydration following humid-heat acclimation. Eight physically active males were heat acclimated (39.8 °C, relative humidity 59.2%) using 17 days of controlled hyperthermia (core temperature: 38.5 °C). Inter-compartmental fluid losses and movements were tracked (radioisotopes and Evans blue dye) during progressive dehydration (cycling) in these same conditions and also during a resting recovery without fluid replacement (28 °C), before (day 1), during (day 8) and after heat acclimation (day 22). On days 8 and 22, there were significant increases in total body water, interstitial fluid and plasma volume (P 0.05). The baseline plasma volume remained expanded throughout: 43.4 [±2.6 (day 1)], 49.1 [±2.4 (day 8); P recovery, plasma volume restoration commenced, with the intracellular fluid contribution becoming more pronounced as acclimation progressed. It is concluded that the plasma volume was not defended more vigorously following humid-heat acclimation. Indeed, a greater fluid loss may well underlie the mechanisms for enhancing plasma volume recovery when heat acclimation is induced using the controlled-hyperthermia technique. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

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.

Dose concept of oncological hyperthermia: Heat-equation considering the cell destruction

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Szasz A

2006-01-01

Full Text Available We shall assume, of course, that the objective of hyperthermia is to destroy the malignant cells. Destruction definitely needs energy. Description and quality assurance of hyperthermia use the Pennes heat equation to describe the processes. However the energy balance of the Pennes-equation does not contain the hyperthermic cell-destruction energy, which is a mandatory factor of the process. We propose a generalization of the Pennes-equation, inducing the entire energy balance. The new paradigm could be a theoretical basis of the till now empirical dose-construction for oncological hyperthermia. The cell destruction is a non-equilibrium thermodynamical process, described by the equations of chemical reactions. The dynamic behavior (time dependence has to be considered in this approach. We are going to define also a dose concept that can be objectively compared with other oncological methods. We show how such empirical dose as CEM43oC could be based theoretically as well.

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)

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...

[Kinetics of catalase inactivation induced by ultrasonic cavitation].

Science.gov (United States)

Potapovich, M V; Eremin, A N; Metelitsa, D I

2003-01-01

Kinetic patterns of sonication-induced inactivation of bovine liver catalase (CAT) were studied in buffer solutions (pH 4-11) within the temperature range from 36 to 55 degrees C. Solutions of CAT were exposed to low-frequency (20.8 kHz) ultrasound (specific power, 48-62 W/cm2). The kinetics of CAT inactivation was characterized by effective first-order rate constants (s-1) of total inactivation (kin), thermal inactivation (*kin), and ultrasonic inactivation (kin(us)). In all cases, the following inequality was valid: kin > *kin. The value of kin(us) increased with the ultrasound power (range, 48-62 W/cm2) and exhibited a strong dependence on pH of the medium. On increasing the initial concentration of CAT (0.4-4.0 nM), kin(us) decreased. The three rate constants were minimum within the range of pH 6.5-8; their values increased considerably at pH 9. At 36-55 degrees C, temperature dependence of kin(us) was characterized by an activation energy (Eact) of 19.7 kcal/mol, whereas the value of Eact for CAT thermoinactivation was equal to 44.2 kcal/mol. Bovine serum and human serum albumins (BSA and HSA, respectively) inhibited sonication-induced CAT inactivation; complete prevention was observed at concentrations above 2.5 micrograms/ml. Dimethyl formamide (DMFA), a scavenger of hydroxyl radicals (HO.), prevented sonication-induced CAT inactivation at 10% (kin and *kin increased with the content of DMFA at concentrations in excess of 3%). The results obtained indicate that free radicals generated in the field of ultrasonic cavitation play a decisive role in the inactivation of CAT, which takes place when its solutions are exposed to low-frequency ultrasound. However, the efficiency of CAT inactivation by the radicals is determined by (1) the degree of association between the enzyme molecules in the reaction medium and (2) the composition thereof.

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

Application of magnetically induced hyperthermia in the model protozoan Crithidia fasciculata as a potential therapy against parasitic infections

Directory of Open Access Journals (Sweden)

Grazú V

2012-10-01

Full Text Available V Grazú,1 AM Silber,2 M Moros,1 L Asín,1 TE Torres,1,3,5 C Marquina,3,4 MR Ibarra,1,3 GF Goya1,31Instituto de Nanociencia de Aragón (INA, Universidad de Zaragoza, Zaragoza, Spain; 2Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil; 3Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza, Zaragoza, Spain; 4Instituto de Ciencia de Materiales de Aragón (ICMA, CSIC, Universidad de Zaragoza, Zaragoza, Spain; 5Laboratorio de Microscopías Avanzadas (LMA, Universidad de Zaragoza, Zaragoza, SpainBackground: Magnetic hyperthermia is currently a clinical therapy approved in the European Union for treatment of tumor cells, and uses magnetic nanoparticles (MNPs under time-varying magnetic fields (TVMFs. The same basic principle seems promising against trypanosomatids causing Chagas disease and sleeping sickness, given that the therapeutic drugs available have severe side effects and that there are drug-resistant strains. However, no applications of this strategy against protozoan-induced diseases have been reported so far. In the present study, Crithidia fasciculata, a widely used model for therapeutic strategies against pathogenic trypanosomatids, was targeted with Fe3O4 MNPs in order to provoke cell death remotely using TVMFs.Methods: Iron oxide MNPs with average diameters of approximately 30 nm were synthesized by precipitation of FeSO4 in basic medium. The MNPs were added to C. fasciculata choanomastigotes in the exponential phase and incubated overnight, removing excess MNPs using a DEAE-cellulose resin column. The amount of MNPs uploaded per cell was determined by magnetic measurement. The cells bearing MNPs were submitted to TVMFs using a homemade AC field applicator (f = 249 kHz, H = 13 kA/m, and the temperature variation during the experiments was measured. Scanning electron microscopy was used to assess morphological changes after the TVMF

Transient mild hyperthermia induces E-selectin mediated localization of mesoporous silicon vectors in solid tumors.

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Dickson K Kirui

Full Text Available BACKGROUND: Hyperthermia treatment has been explored as a strategy to overcome biological barriers that hinder effective drug delivery in solid tumors. Most studies have used mild hyperthermia treatment (MHT to target the delivery of thermo-sensitive liposomes carriers. Others have studied its application to permeabilize tumor vessels and improve tumor interstitial transport. However, the role of MHT in altering tumor vessel interfacial and adhesion properties and its relationship to improved delivery has not been established. In the present study, we evaluated effects of MHT treatment on tumor vessel flow dynamics and expression of adhesion molecules and assessed enhancement in particle localization using mesoporous silicon vectors (MSVs. We also determined the optimal time window at which maximal accumulation occur. RESULTS: In this study, using intravital microscopy analyses, we showed that temporal mild hyperthermia (∼1 W/cm(2 amplified delivery and accumulation of MSVs in orthotopic breast cancer tumors. The number of discoidal MSVs (1000×400 nm adhering to tumor vasculature increased 6-fold for SUM159 tumors and 3-fold for MCF-7 breast cancer tumors. By flow chamber experiments and Western blotting, we established that a temporal increase in E-selectin expression correlated with enhanced particle accumulation. Furthermore, MHT treatment was shown to increase tumor perfusion in a time-dependent fashion. CONCLUSIONS: Our findings reveal that well-timed mild hyperthermia treatment can transiently elevate tumor transport and alter vascular adhesion properties and thereby provides a means to enhance tumor localization of non-thermally sensitive particles such as MSVs. Such enhancement in accumulation could be leveraged to increase therapeutic efficacy and reduce drug dosing in cancer therapy.

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.

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

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

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

The individual and combined effects of γ rays and hyperthermia on the development of embryonic brains

International Nuclear Information System (INIS)

Yang Yepeng; Ruan Ming; Liu Jingyuan; Hong Min; Lu Chunlin

2000-01-01

Objective: To observe the individual and combined effects of exposure to γ rays and hyperthermia on the development of embryonic brains. Methods: the pregnant LACA mice were exposed to 1.0 Gy 60 Co-γ rays, 42 degree C hyperthermia for 10 minutes or the two treatments combined together on day 9 of pregnancy. The females were sacrificed on day 18 of pregnancy and the fetuses were gained by cesarean section. The appearance of fetuses was observed and, then, the weight of fetal brains, the cell number of whole brains, the contents of nucleic acid and protein in brain tissue and the activity of acetylcholine esterase (AChE) in brain tissue as a marker for cholinergic neurons were determined. Results: Nervous tube defects did not occur in all groups. Compared with the control group, all the indices determined significantly declined in the radiation group while the cell number of whole brains and the AChE activity in brain tissue significantly decreased in the hyperthermia group. In the group of hyperthermia in advance, 4 hours later, followed by exposure to radiation, the AChE activity in brain tissue was significantly higher than the single radiation group. In the group of prior radiation exposure, 4 hours later, followed by hyperthermia, all the indices did not present significant difference from the single radiation group. Conclusion: The effects of 42 degree C hyperthermia for 10 minutes on the development of mouse embryo's brains are much weaker than 1.0 Gy γ radiation. It seems that the hyperthermia in advance can induce mouse fetuses to produce the cross adaptability to the following exposure to radiation. Exposure to γ radiation followed by hyperthermia does not present and additive action or a synergistic action

Desoxyribonucleic acid (DNA) synthesis in vitro by thymus and spleen cells of the rat after hyperthermia

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Tempel, K.; Spath, A.

1988-03-01

The inhibition of the semiconservative and restorative DNA synthesis caused by hyperthermia (30 to 60 min, 43/sup 0/C) was significantly higher in spleen cells than in thymus cells. The DNA repair synthesis of thymus cells measured at 37/sup 0/C was increased by about two times the initial value after a pre-incubation of 30 to 90 min and 30 to 60 min, respectively, with 37 and 43/sup 0/C, respectively. Under the same conditions, the /sup 3/H-thymidine incorporation into the DNA of spleen cells diminished proportionally to the pre-incubation time after a pre-incubation of 30 and 45 min, respectively, with 43 and 37/sup 0/C, respectively. When hyperthermia and inhibitors of DNA synthesis or DNA repair (hydroxyurea, 1-..beta..-D-arabinofuranosylcytosine, 3', 5'-didesoxythymidine, and 3-aminobenzamide) were combined, overadditive effects - without cellspecific particularities - were seen only in the case of 3-aminobenzamide. Only in thymus cells, the inhibitor of DNA topoisomerase II novobiocin caused an overadditive reinforcement of the inhibition induced by hyperthermia of the semiconservative DNA synthesis. The stimulation of DNA repair synthesis in thymus cells caused by novobiocin with the aid of DNA polymerase ..beta.. could be compensated by hyperthermia. The sedimentation of thymus and spleen cell nucleoids was increased after hyperthermia. The results suggest a special importance of DNA topology and of the DNA polymerase ..beta.. activity for the cellular effect of hyperthermia.

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

Polyamines and polyamine biosynthesis in cells exposed to hyperthermia

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Gerner, E.W.; Stickney, D.G.; Herman, T.S.; Fuller, D.J.

1983-02-01

The issue of how polyamines act to sensitize cultured cells to the lethal effects of hyperthermia was investigated using Chinese hamster cells which were induced to express thermotolerance. Intracellular levels of these naturally occurring polycations were manipulated in certain situations by treating whole cells with methylglyoxal bis-(guanylhydrazone), an inhibitor of the S-adenosyl-L-methionine decarboxylases. Exogenous spermine as low as 100 ..mu..M in the culture media dramatically sensitized cells expressing thermotolerance to the lethal effects of subsequent 42/sup 0/C exposures. When thermotolerance was differentially induced in cultures exposed to 42.4/sup 0/C by varying the rate of heating from 37 to 42.4/sup 0/C, the most resistant cells and the highest levels of intracellular spermidine and spermine. This finding was explainable in part by the observation that the putrescine-dependent S-adenosyl-L-methionine decarboxylase activity was minimally affected in cells expressng the greatest degree of thermotolerance. When this enzyme activity was inhibited by drug, lowered intracellular polyamine levels did not correspond with subsequent survival responses to heat. Interestingly, cultures treated with methylglyoxal bis-(guanylhydrazone) 24 hr previous to heat exposure showed a reduced capacity to express rate of heating-induced thermotolerance. Together, these results demonstrate that the polyamines, especially spermidine and spermine, enhance hyperthermia-induced cell killing by some mechanism involving the plasma membrane. Further, our data suggest that methylglyoxal bis-(guanylhydrazone) can act to affect thermal responses by a mechanism(s) other than modification of intracellular polyamine levels.

Experimental investigation of ultrasonic velocity anisotropy in ...

Indian Academy of Sciences (India)

Permanent link: https://www.ias.ac.in/article/fulltext/pram/077/02/0345-0355. Keywords. Magnetic fluids; ultrasonic wave; sound velocity; anisotropy. Abstract. Magnetic field-induced dispersion of ultrasonic velocity in a Mn0.7Zn0.3Fe2O4 fluid (applied magnetic field is perpendicular to the ultrasonic propagation vector) is ...

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

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)

Intramuscular injection of malignant hyperthermia trigger agents induces hypermetabolism in susceptible and nonsusceptible individuals.

Science.gov (United States)

Metterlein, Thomas; Schuster, Frank; Kranke, Peter; Roewer, Norbert; Anetseder, Martin

2010-01-01

A new minimally invasive metabolic test for the diagnosis of susceptibility for malignant hyperthermia measuring intramuscular p(CO(2)) and lactate following local application of caffeine and halothane in humans was recently proposed. The present study tested the hypothesis that a more simplified test protocol allows a differentiation between malignant hyperthermia susceptible (MHS) and malignant hyperthermia nonsusceptible (MHN) and control individuals. With approval of the local ethics committee and informed consent, microdialysis and p(CO(2)) probes with attached microtubing were placed into the lateral vastus muscle of six MHS, seven MHN and seven control individuals. Following equilibration, boluses of 500 microl caffeine 80 mmol l(-1) and halothane 10 vol% dissolved in soybean oil were injected locally. p(CO(2)) and lactate were measured spectrophotometrically. The maximal rate of p(CO(2)) increase was significantly higher in MHS than in MHN and control individuals following application of halothane and caffeine, respectively. Intramuscular caffeine injection leads to a significantly higher increase of local lactate levels in MHS than in MHN and control individuals, whereas halothane increased local lactate levels in all investigated groups. Haemodynamic and systemic metabolic parameters did not differ between the investigated groups. Local caffeine and halothane injection increased intramuscular metabolism in MHS individuals significantly more than in the two other groups. In contrast to previous investigations, direct injection of the concentrations of halothane described here increased lactate and p(CO(2)) even in MHN skeletal muscle.

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

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

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

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)

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

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.

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.

Smooth polishing of femtosecond laser induced craters on cemented carbide by ultrasonic vibration method

Science.gov (United States)

Wang, H. P.; Guan, Y. C.; Zheng, H. Y.

2017-12-01

Rough surface features induced by laser irradiation have been a challenging for the fabrication of micro/nano scale features. In this work, we propose hybrid ultrasonic vibration polishing method to improve surface quality of microcraters produced by femtosecond laser irradiation on cemented carbide. The laser caused rough surfaces are significantly smoothened after ultrasonic vibration polishing due to the strong collision effect of diamond particles on the surfaces. 3D morphology, SEM and AFM analysis has been conducted to characterize surface morphology and topography. Results indicate that the minimal surface roughness of Ra 7.60 nm has been achieved on the polished surfaces. The fabrication of microcraters with smooth surfaces is applicable to molding process for mass production of micro-optical components.

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.

Inhibition of sarcoplasmic Ca2+-ATPase increases caffeine- and halothane-induced contractures in muscle bundles of malignant hyperthermia susceptible and healthy individuals

Directory of Open Access Journals (Sweden)

Roewer Norbert

2005-06-01

Full Text Available Abstract Background Malignant hyperthermia (MH is triggered by halogenated anaesthetics and depolarising muscle relaxants, leading to an uncontrolled hypermetabolic state of skeletal muscle. An uncontrolled sarcoplasmic Ca2+ release is mediated via the ryanodine receptor. A compensatory mechanism of increased sarcoplasmic Ca2+-ATPase activity was described in pigs and in transfected cell lines. We hypothesized that inhibition of Ca2+ reuptake via the sarcoplasmic Ca2+-ATPase (SERCA enhances halothane- and caffeine-induced muscle contractures in MH susceptible more than in non-susceptible skeletal muscle. Methods With informed consent, surplus muscle bundles of 7 MHS (susceptible, 7 MHE (equivocal and 16 MHN (non-susceptible classified patients were mounted to an isometric force transducer, electrically stimulated, preloaded and equilibrated. Following 15 min incubation with cyclopiazonic acid (CPA 25 μM, the European MH standard in-vitro-contracture test protocol with caffeine (0.5; 1; 1.5; 2; 3; 4 mM and halothane (0.11; 0.22; 0.44; 0.66 mM was performed. Data as median and quartiles; Friedman- and Wilcoxon-test for differences with and without CPA; p Results Initial length, weight, maximum twitch height, predrug resting tension and predrug twitch height of muscle bundles did not differ between groups. CPA increased halothane- and caffeine-induced contractures significantly. This increase was more pronounced in MHS and MHE than in MHN muscle bundles. Conclusion Inhibition of the SERCA activity by CPA enhances halothane- and caffeine-induced contractures especially in MHS and MHE skeletal muscle and may help for the diagnostic assignment of MH susceptibility. The status of SERCA activity may play a significant but so far unknown role in the genesis of malignant hyperthermia.

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

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

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

A role for D1 dopamine receptors in striatal methamphetamine-induced neurotoxicity.

Science.gov (United States)

Friend, Danielle M; Keefe, Kristen A

2013-10-25

Methamphetamine (METH) exposure results in long-term damage to the dopamine system in both human METH abusers and animal models. One factor that has been heavily implicated in this METH-induced damage to the dopaminergic system is the activation of D1 dopamine (DA) receptors. However, a significant caveat to the studies investigating the role of the receptor in such toxicity is that genetic and pharmacological manipulations of the D1 DA receptor also mitigate METH-induced hyperthermia. Importantly, METH-induced hyperthermia is tightly associated with the neurotoxicity, such that simply cooling animals during METH exposure protects against the neurotoxicity. Therefore, it is difficult to determine whether D1 DA receptors per se play an important role in METH-induced neurotoxicity or whether the protection observed simply resulted from a mitigation of METH-induced hyperthermia. To answer this important question, the current study infused a D1 DA receptor antagonist into striatum during METH exposure while controlling for METH-induced hyperthermia. Here we found that even when METH-induced hyperthermia is maintained, the coadministration of a D1 DA receptor antagonist protects against METH-induced neurotoxicity, strongly suggesting that D1 DA receptors play an important role in METH-induced neurotoxicity apart from the mitigation of METH-induced hyperthermia. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

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.

Monitoring of soluble starch hydrolysis induced by α-amylase from Aspergillus oryzae using ultrasonic spectroscopy

Science.gov (United States)

Sierra, Carlos; Resa, Pablo; Buckin, Vitaly; Elvira, Luis

2012-05-01

The online monitoring of enzymatic starch hydrolysis is an important issue for several industrial sectors, mainly in the alimentary industry. Ultrasonic non-invasive methods based on the detection of wave velocity and amplitude changes can be used to study this enzymatic reaction. These wave propagating changes are result of physicalchemical modifications produced in the media by the starch hydrolysis. In this work the starch hydrolysis induced by the enzyme α-amylase from Aspergillus oryzae is studied. This biochemical reaction has been monitored using a high-resolution ultrasonic spectroscopy (HR-US) which is non-invasive and nondestructive. The measured time profiles o of ultrasonic velocity are explained in terms of the starch hydrolysis and the subsequent production of oligosaccharides as a consequence of the enzymatic action. The obtained results have been compared to a conventional off-line technique used in biochemistry, the iodine-starch reaction, a spectrophotometric method to quantify the amount of starch remaining in the medium. The combination of these two types of measurement provides more complete information about the biochemical processes occurred during hydrolysis.

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.

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....

The proliferation induced by hyperthermia in NB69 cells is offset by a radar-like signal

International Nuclear Information System (INIS)

Trillo Ruiz, M. A.; Martinez Pascual, M. A.; Cid Torres, M. A.; Pague de la Vega, J. E.; Chacon Vargas, L.; Ubeda Maeso, A.

2011-01-01

The present study describes the proliferative response of the cell line NB69 human neuroblastoma, the simultaneous exposure to two physical agents: mild hyperthermia (+1 degree centigrade) and a pulsed RF signal subtermica.

Magnetic Hyperthermia and Oxidative Damage to DNA of Human Hepatocarcinoma Cells.

Science.gov (United States)

Cellai, Filippo; Munnia, Armelle; Viti, Jessica; Doumett, Saer; Ravagli, Costanza; Ceni, Elisabetta; Mello, Tommaso; Polvani, Simone; Giese, Roger W; Baldi, Giovanni; Galli, Andrea; Peluso, Marco E M

2017-04-29

Nanotechnology is addressing major urgent needs for cancer treatment. We conducted a study to compare the frequency of 3-(2-deoxy-β-d-erythro-pentafuranosyl)pyrimido[1,2-α]purin-10(3 H )-one deoxyguanosine (M₁dG) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) adducts, biomarkers of oxidative stress and/or lipid peroxidation, on human hepatocarcinoma HepG2 cells exposed to increasing levels of Fe₃O₄-nanoparticles (NPs) versus untreated cells at different lengths of incubations, and in the presence of increasing exposures to an alternating magnetic field (AMF) of 186 kHz using 32 P-postlabeling. The levels of oxidative damage tended to increase significantly after ≥24 h of incubations compared to controls. The oxidative DNA damage tended to reach a steady-state after treatment with 60 μg/mL of Fe₃O₄-NPs. Significant dose-response relationships were observed. A greater adduct production was observed after magnetic hyperthermia, with the highest amounts of oxidative lesions after 40 min exposure to AMF. The effects of magnetic hyperthermia were significantly increased with exposure and incubation times. Most important, the levels of oxidative lesions in AMF exposed NP treated cells were up to 20-fold greater relative to those observed in nonexposed NP treated cells. Generation of oxidative lesions may be a mechanism by which magnetic hyperthermia induces cancer cell death.

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)

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

Sensitivity of hyperthermia-treated human cells to killing by ultraviolet or gamma radiation

International Nuclear Information System (INIS)

Mitchel, R.E.; Smith, B.P.; Wheatly, N.; Chan, A.; Child, S.; Paterson, M.C.

1985-01-01

Human xeroderma pigmentosum (XP) or Fanconi anemia (FA) fibroblasts displayed shouldered 45 0 C heat survival curves not significantly different from normal fibroblasts, a result similar to that previously found for ataxia telangiectasia (AT) cells, indicating heat resistance is not linked to either uv or low-LET ionizing radiation resistance. Hyperthermia (45 0 C) sensitized normal and XP fibroblasts to killing by gamma radiation but failed to sensitize the cells to the lethal effects of 254 nm uv radiation. Thermal inhibition of repair of ionizing radiation lesions but not uv-induced lesions appears to contribute synergistically to cell death. The thermal enhancement ratio (TER) for the synergistic interaction of hyperthermia (45 0 C, 30 min) and gamma radiation was significantly lower in one FA and two strains (TER = 1.7-1.8) than that reported previously for three normal strains (TER = 2.5-3.0). These XP and FA strains may be more gamma sensitive than normal human fibroblasts. Since hyperthermia treatment only slightly increases the gamma-radiation sensitivity of ataxia telangiectasia (AT) fibroblasts compared to normal strains, it is possible that the degree of thermal enhancement attainable reflects the genetically inherent ionizing radiation repair capacity of the cells. The data indicate that both repair inhibition and particular lesion types are required for lethal synergism between heat and radiation. We therefore postulate that the transient thermal inhibition of repair results in the conversion of gamma-induced lesions to irrepairable lethal damage, while uv-type damage can remain unaltered during this period

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

the ability to effectively deliver ultrasound hyperthermia or 60 Co teletherapy. With the en-face approach the ultrasonic patterns generated with and without the reflector demonstrated that the ultrasound system maintained both a uniform and controllable heating pattern. The 60 Co beam had no effect on the performance of the thermocouple thermometers. The radiation beam is attenuated nearly uniformly by the reflector system. To date, 10 patients have been treated with the en-face approach and 12 have been treated with the orthogonal approach (90 treatments). Conclusions: The clinical implementation of ultrasound hyperthermia simultaneous with 60 Co irradiation is technically and clinically feasible without any complications or hazards to the patient. The implementation of a reflecting device allows en-face delivery of both the ultrasound and 60 Co irradiation. Temperatures obtained during simultaneous treatments are comparable to those historically obtained during sequential treatments with the same commercial ultrasound device

Whole Body Hyperthermia in Mice Confers Delayed Radioprotection at Cellular and Tissue Levels: Inducible Heat Shock Proteins as Endogenous Radioprotectors

International Nuclear Information System (INIS)

Malytina, Y. V.; Sements, T. N.; Semina, O. V.; Mosin, A. F.; Kabakov, A.

2004-01-01

It was previously shown on heat shock protein (Hsp)-over expressing cell lines that the increased intracellular content of Hsp 70 or Hsp27 is associated with the elevated radioresistance. However, it was so far unknown whether the in vivo Fsp induction by stressful preconditioning can confer radioprotection at the tissue and cellular levels. In the present study, we examined how the in vivo up-regulation of the Hsp expression in response to mild whole body hyperthermia (42 degrees C, 10 min) in mice changes susceptibility of their bone marrow stem cells and thymocytes to subsequent gamma-irradiation. to assess the expectable contribution of stress-inducible Hsp we used injections with Quercetin, a flavonoid inhibiting the stress-responsive Hsp induction. The results demonstrate that the bone marrow stem cells and thymocytes from heat-preconditioned mice were more radioresistant than those from the non-preconditioned animals. the radioprotection was well manifested if mice or their isolated thymocytes were irradiated 18-25 h after the in vivo hyperthermia. This delayed radioprotection resulting from the heat preconditioning was suppressed in Quercetin-injected mice. The revealed correlation between the intracellular Hsp accumulation and the acquired Quercetin-sensitive radioprotection suggests a beneficial role of Hsps as of endogenous radioprotectors. Our finding discovers new ways for artificial modulation of effects of irradiation on target cells via manipulating the Hsp expression. (Author) 17 refs

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

Nano-magnetite coated with gold: alternative oncological therapy with magnetic hyperthermia

International Nuclear Information System (INIS)

Cordova F, T.; Jimenez G, O.; Basurto I, G.; Martinez E, J. C.

2017-10-01

Localized hyperthermia performed through the use of nanoparticles is one of the most promising procedures for the cancer treatment. In this work, the synthesis of magnetite nanoparticles (Fe 2 O 3 ) was carried out using the thermal decomposition method. Subsequently, these nanoparticles were coated with gold and suspended in aqueous phase. As a result, nanoparticles capable of being heated by the application of an alternating magnetic field or through the use of infrared radiation were obtained. As an additional feature, these nanoparticles are biocompatible thanks to their golden coating. The synthesized nanoparticles can be functionalized by the conjugation of a molecule (aptamer, antibody, peptide, etc.) whose target is a cancer cell in order to adhere to it the nanoparticle-marker complex, to subsequently carry out a heating with the objective of induce cell death. In conclusion, the synthesized nanoparticles allow providing an alternative treatment for cancer through the use of localized hyperthermia, either using magnetic or infrared heating. (Author)

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

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

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

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.

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

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.

Esterification of jatropha oil via ultrasonic irradiation with auto-induced temperature-rise effect

International Nuclear Information System (INIS)

Andrade-Tacca, Cesar Augusto; Chang, Chia-Chi; Chen, Yi-Hung; Manh, Do-Van; Chang, Ching-Yuan; Ji, Dar-Ren; Tseng, Jyi-Yeong; Shie, Je-Lueng

2014-01-01

Auto-induced temperature-rise effects of ultrasonic irradiation (UI) on the esterification performance of jatropha oil (JO) were studied. Comparisons with other methods of mechanical mixing (MM) and hand shaking mixing were made. Major system parameters examined include: esterification time (t E ), settling time (t S ) after esterification and temperature. Properties of acid value (AV), iodine value (IV), kinematic viscosity (KV) and density of JO and ester product were measured. The esterification conversion efficiencies (η) were determined and assessed. Sulfuric acid was used to catalyze the esterification using methyl alcohol. For esterification without temperature control, η at t E  = 10 and 30 min for UI of 56.73 and 83.23% are much higher than those for MM of 36.76 and 42.48%, respectively. At t E  = 10 min, the jatropha oil esters produced via UI and MM respectively possess AV of 15.82 and 23.12 mg KOH/g, IV of 111.49 and 113.22 g I 2 /100 g, KV of 22.41 and 22.51 mm 2 /s and density of 913.8 and 913.58 kg/m 3 , showing that UI is much better than MM in enhancing the reduction of AV. The t E exhibits more vigorous effect on AV for UI than MM. The UI offers auto-induced temperature-rise, improving the mixing and esterification extents. - Highlights: • Esterification of jatropha oil is pronounced under ultrasonic irradiation (UI). • UI can auto-induce temperature rise. • The induced temperature rise assists the mixing of UI in enhancing esterification. • UI offers better esterification than mechanical mixing with external heating. • An 83.23% reduction of FFA in jatropha-ester is achievable via UI in 30 min

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.

Magnetic Hyperthermia and Oxidative Damage to DNA of Human Hepatocarcinoma Cells

Directory of Open Access Journals (Sweden)

Filippo Cellai

2017-04-01

Full Text Available Nanotechnology is addressing major urgent needs for cancer treatment. We conducted a study to compare the frequency of 3-(2-deoxy-β-d-erythro-pentafuranosylpyrimido[1,2-α]purin-10(3H-one deoxyguanosine (M1dG and 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG adducts, biomarkers of oxidative stress and/or lipid peroxidation, on human hepatocarcinoma HepG2 cells exposed to increasing levels of Fe3O4-nanoparticles (NPs versus untreated cells at different lengths of incubations, and in the presence of increasing exposures to an alternating magnetic field (AMF of 186 kHz using 32P-postlabeling. The levels of oxidative damage tended to increase significantly after ≥24 h of incubations compared to controls. The oxidative DNA damage tended to reach a steady-state after treatment with 60 μg/mL of Fe3O4-NPs. Significant dose–response relationships were observed. A greater adduct production was observed after magnetic hyperthermia, with the highest amounts of oxidative lesions after 40 min exposure to AMF. The effects of magnetic hyperthermia were significantly increased with exposure and incubation times. Most important, the levels of oxidative lesions in AMF exposed NP treated cells were up to 20-fold greater relative to those observed in nonexposed NP treated cells. Generation of oxidative lesions may be a mechanism by which magnetic hyperthermia induces cancer cell death.

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

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

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.

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

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.)

Ultrasonic Testing

Energy Technology Data Exchange (ETDEWEB)

Lee, Hyeong Jun; Kuk, Jeong Han

2002-02-15

This book introduces ultrasonic testing, which tells of outline of ultrasonic testing, principle of ultrasonic testing, prosperities of ultrasonic waves, radiographic test and ultrasonic test, basic theory on ultrasonic testing, mode conversion, transmission and diffraction, ultrasonic flaw detection and probe, standard test piece and reference test piece, like KS(JIS) ASME and ASTM, classification and properties of ultrasonic testing, straight beam method, angle beam method, ASME SEC.V.Art.5 ASTMA 388 and KS B 0817 Korean industrial standard.

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)

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.

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)

THE FIRST EXPERIENCE OF USING LOCAL HYPERTHERMIA IN COMBINED MODALITY TREATMENT OF OPERABLE NON-SMALL CELL LUNG CANCER

Directory of Open Access Journals (Sweden)

A. Yu. Dobrodeev

2015-01-01

Full Text Available The paper presents the first experience in treating 5 patients with stage II–III non-small cell lung cancer using combined modality treatment including 40 Gy preoperative hyperfractionated radiotherapy with concurrent 2 cycles of paclitaxel/carboplatin chemotherapy and local hyperthermia (10 sessions followed by radical surgery. The overal response rate to preoperative treatment was 80 %. Chemotherapy was well tolerated and hyperthermia resulted no in adverse effects. All patients underwent surgery (4 lobectomies and 1 pneumonectomy. No complications were observed in the postoperative period. The follow-up period ranged from 6 to 20 months. No evidence of disease progression and radiation-induced damages were observed.

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.

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

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

Hyperthermia-induced apoptosis

NARCIS (Netherlands)

Nijhuis, E.H.A.

2008-01-01

This thesis describes a number of studies that investigated several aspects of heat-induced apoptosis in human lymphoid malignancies. Cells harbour both pro- and anti-apoptotic proteins and the balance between these proteins determines whether a cell is susceptible to undergo apoptosis. In this

Long-Term Improvement in Treatment Outcome After Radiotherapy and Hyperthermia in Locoregionally Advanced Cervix Cancer: An Update of the Dutch Deep Hyperthermia Trial

International Nuclear Information System (INIS)

Franckena, Martine; Stalpers, Lukas J.A.; Koper, Peter C.M.; Wiggenraad, Ruud G.J.; Hoogenraad, Wim J.; Dijk, Jan D.P. van; Warlam-Rodenhuis, Carla C.; Jobsen, Jan J.; Rhoon, Gerard C. van; Zee, Jacoba van der

2008-01-01

Purpose: The local failure rate in patients with locoregionally advanced cervical cancer is 41-72% after radiotherapy (RT) alone, whereas local control is a prerequisite for cure. The Dutch Deep Hyperthermia Trial showed that combining RT with hyperthermia (HT) improved 3-year local control rates of 41-61%, as we reported earlier. In this study, we evaluate long-term results of the Dutch Deep Hyperthermia Trial after 12 years of follow-up. Methods and Materials: From 1990 to 1996, a total of 114 women with locoregionally advanced cervical carcinoma were randomly assigned to RT or RT + HT. The RT was applied to a median total dose of 68 Gy. The HT was given once weekly. The primary end point was local control. Secondary end points were overall survival and late toxicity. Results: At the 12-year follow-up, local control remained better in the RT + HT group (37% vs. 56%; p = 0.01). Survival was persistently better after 12 years: 20% (RT) and 37% (RT + HT; p = 0.03). World Health Organization (WHO) performance status was a significant prognostic factor for local control. The WHO performance status, International Federation of Gynaecology and Obstetrics (FIGO) stage, and tumor diameter were significant for survival. The benefit of HT remained significant after correction for these factors. European Organization for Research and Treatment of Cancer Grade 3 or higher radiation-induced late toxicities were similar in both groups. Conclusions: For locoregionally advanced cervical cancer, the addition of HT to RT resulted in long-term major improvement in local control and survival without increasing late toxicity. This combined treatment should be considered for patients who are unfit to receive chemotherapy. For other patients, the optimal treatment strategy is the subject of ongoing research

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.

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...

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

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

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

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

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)

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

Freeze-thaw-induced embolism in Pinus contorta: centrifuge experiments validate the 'thaw-expansion hypothesis' but conflict with ultrasonic emission data.

Science.gov (United States)

Mayr, Stefan; Sperry, John S

2010-03-01

*The 'thaw-expansion hypothesis' postulates that xylem embolism is caused by the formation of gas bubbles on freezing and their expansion on thawing. We evaluated the hypothesis using centrifuge experiments and ultrasonic emission monitoring in Pinus contorta. *Stem samples were exposed to freeze-thaw cycles at varying xylem pressure (P) in a centrifuge before the percentage loss of hydraulic conductivity (PLC) was measured. Ultrasonic acoustic emissions were registered on samples exposed to freeze-thaw cycles in a temperature chamber. *Freeze-thaw exposure of samples spun at -3 MPa induced a PLC of 32% (one frost cycle) and 50% (two cycles). An increase in P to -0.5 MPa during freezing had no PLC effect, whereas increased P during thaw lowered PLC to 7%. Ultrasonic acoustic emissions were observed during freezing and thawing at -3 MPa, but not in air-dried or water-saturated samples. A decrease in minimum temperature caused additional ultrasonic acoustic emissions, but had no effect on PLC. *The centrifuge experiments indicate that the 'thaw-expansion hypothesis' correctly describes the embolization process. Possible explanations for the increase in PLC on repeated frost cycles and for the ultrasonic acoustic emissions observed during freezing and with decreasing ice temperature are discussed.

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 ...

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.

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.

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

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

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.

A computational modeling approach of the jet-like acoustic streaming and heat generation induced by low frequency high power ultrasonic horn reactors.

Science.gov (United States)

Trujillo, Francisco Javier; Knoerzer, Kai

2011-11-01

High power ultrasound reactors have gained a lot of interest in the food industry given the effects that can arise from ultrasonic-induced cavitation in liquid foods. However, most of the new food processing developments have been based on empirical approaches. Thus, there is a need for mathematical models which help to understand, optimize, and scale up ultrasonic reactors. In this work, a computational fluid dynamics (CFD) model was developed to predict the acoustic streaming and induced heat generated by an ultrasonic horn reactor. In the model it is assumed that the horn tip is a fluid inlet, where a turbulent jet flow is injected into the vessel. The hydrodynamic momentum rate of the incoming jet is assumed to be equal to the total acoustic momentum rate emitted by the acoustic power source. CFD velocity predictions show excellent agreement with the experimental data for power densities higher than W(0)/V ≥ 25kWm(-3). This model successfully describes hydrodynamic fields (streaming) generated by low-frequency-high-power ultrasound. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

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

Implication of prostaglandins and histamine H1 and H2 receptors in radiation-induced temperature responses of rats

International Nuclear Information System (INIS)

Kandasamy, S.B.; Hunt, W.A.; Mickley, G.A.

1988-01-01

Exposure of rats to 1-15 Gy gamma radiation ( 60 Co) induced hyperthermia, whereas 20-200 Gy induced hypothermia. Exposure either to the head or to the whole body to 10 Gy induced hyperthermia, while body-only exposure produced hypothermia. This observation indicates that radiation-induced fever is a result of a direct effect on the brain. The hyperthermia due to 10 Gy was significantly attenuated by the pre- or post-treatment with a cyclooxygenase inhibitor, indomethacin. Hyperthermia was also altered by the central administration of a mu-receptor antagonist naloxone but only at low doses of radiation. These findings suggest that radiation-induced hyperthermia may be mediated through the synthesis and release of prostaglandins in the brain and to a lesser extent to the release of endogenous opioid peptides. The release of histamine acting on H1 and H2 receptors may be involved in radiation-induced hypothermia, since both the H1 receptor antagonist, mepyramine, and H2 receptor antagonist, cimetidine, antagonized the hypothermia. The results of these studies suggest that the release of neurohumoral substances induced by exposure to ionizing radiation is dose dependent and has different consequences on physiological processes such as the regulation of body temperature. Furthermore, the antagonism of radiation-induced hyperthermia by indomethacin may have potential therapeutic implications in the treatment of fever resulting from accidental irradiations

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.

Magnetomotive Optical Coherence Elastography for Magnetic Hyperthermia Dosimetry Based on Dynamic Tissue Biomechanics

Science.gov (United States)

Huang, Pin-Chieh; Pande, Paritosh; Ahmad, Adeel; Marjanovic, Marina; Spillman, Darold R.; Odintsov, Boris; Boppart, Stephen A.

2016-01-01

Magnetic nanoparticles (MNPs) have been used in many diagnostic and therapeutic biomedical applications over the past few decades to enhance imaging contrast, steer drugs to targets, and treat tumors via hyperthermia. Optical coherence tomography (OCT) is an optical biomedical imaging modality that relies on the detection of backscattered light to generate high-resolution cross-sectional images of biological tissue. MNPs have been utilized as imaging contrast and perturbative mechanical agents in OCT in techniques called magnetomotive OCT (MM-OCT) and magnetomotive elastography (MM-OCE), respectively. MNPs have also been independently used for magnetic hyperthermia treatments, enabling therapeutic functions such as killing tumor cells. It is well known that the localized tissue heating during hyperthermia treatments result in a change in the biomechanical properties of the tissue. Therefore, we propose a novel dosimetric technique for hyperthermia treatment based on the viscoelasticity change detected by MM-OCE, further enabling the theranostic function of MNPs. In this paper, we first review the basic principles and applications of MM-OCT, MM-OCE, and magnetic hyperthermia, and present new preliminary results supporting the concept of MM-OCE-based hyperthermia dosimetry. PMID:28163565

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

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.

Cellular radiation effects and hyperthermia cell cycle kinetics of radiation sensitive mutants of saccharomyces cerevisiae after x-irradiation and hyperthermia

International Nuclear Information System (INIS)

Fingerhut, R.; Kiefer, J.; Otto, F.

1983-01-01

Radiosensitive mutants rad2, rad9, and rad51 of Saccharomyces cerevisiae were X-irradiated with 120 Gy or 60 Gy, heated at 50 0 C for 30 min or treated with a combination of both and incubated in nutrient medium at 30 0 C. Cell number, percentage of budding cells, and cell cycle progression were determined in 45-min intervals. Cell cycle kinetics were investigated by flow cytofluorometry. Hyperthermia leads mainly to a lengthening of G1, whereas X-rays arrest cells of the rad2 and rad9 mutant in G2 and the rad51 - mutant additionaly in a state with DNA contents above G2. Cell division dealy is influenced by oxygen in all strains but to a lesser extent in the rad2 mutant. The effect of the combined treatment appears to be merely additive in the rad2 and rad9 mutant while the rad51 mutant is sensitized to X-irradiation by hyperthermia. No selective action of hyperthermia on hypoxic cells was found. (orig.)

Pharmacogenetics and pathophysiology of CACNA1S mutations in malignant hyperthermia.

Science.gov (United States)

Beam, Teresa A; Loudermilk, Emily F; Kisor, David F

2017-02-01

A review of the pharmacogenetics (PGt) and pathophysiology of calcium voltage-gated channel subunit alpha1 S (CACNA1S) mutations in malignant hyperthermia susceptibility type 5 (MHS5; MIM #60188) is presented. Malignant hyperthermia (MH) is a life-threatening hypermetabolic state of skeletal muscle usually induced by volatile, halogenated anesthetics and/or the depolarizing neuromuscular blocker succinylcholine. In addition to ryanodine receptor 1 (RYR1) mutations, several CACNA1S mutations are known to be risk factors for increased susceptibility to MH (MHS). However, the presence of these pathogenic CACNA1S gene variations cannot be used to positively predict MH since the condition is genetically heterogeneous with variable expression and incomplete penetrance. At present, one or at most six CACNA1S mutations display significant linkage or association either to clinically diagnosed MH or to MHS as determined by contracture testing. Additional pathogenic variants in CACNA1S, either alone or in combination with genes affecting Ca 2+ homeostasis, are likely to be discovered in association to MH as whole exome sequencing becomes more commonplace. Copyright © 2017 the American Physiological Society.

Ccl22/MDC, is a prostaglandin dependent pyrogen, acting in the anterior hypothalamus to induce hyperthermia via activation of brown adipose tissue.

Science.gov (United States)

Osborn, Olivia; Sanchez-Alavez, Manuel; Dubins, Jeffrey S; Gonzalez, Alejandro Sanchez; Morrison, Brad; Hadcock, John R; Bartfai, Tamas

2011-03-01

CC Chemokine ligand 22 (Ccl22) is a selective, high affinity ligand at the CC chemokine receptor 4 (Ccr4). We have identified cDNAs encoding both ligand and receptor of the Ccl22-Ccr4 pair in cDNA libraries of the anterior hypothalamus/pre-optic area (AH/POA) by PCR. The AH/POA is the key brain region where endogenous pyrogens have been shown to act on warm sensitive neurons to affect thermogenesis in brown adipose tissue (BAT) and other thermogenically responsive tissues. We show that functional Ccr4 receptors are present in the AH/POA neurons as injection of Ccl22 into the POA but not to other hypothalamic nuclei induces an increase in core body temperature as measured by radiotelemetry. Indomethacin (5 mg/kg s.c) pre-treatment markedly reduced the hyperthermia evoked by POA injection of Ccl22 (10 ng/0.5 ul) and thus suggests that this hyperthermia is mediated through cyclooxygenase activation and thus likely through the formation and action of the pyrogen prostaglandin E2. The temperature elevation involves a decrease in the respiratory exchange ratio and increased activation of the brown adipose tissue as demonstrated by ¹⁸F-FDG-PET imaging. We describe a novel role to the ligand Ccl22 and its receptor Ccr4 in the anterior hypothalamus in temperature regulation that depends on the synthesis of the endogenous pyrogen, prostaglandin E2. Copyright © 2010 Elsevier Ltd. All rights reserved.

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...

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)

Excision of x-ray-induced thymine damage in chromatin from heated cells

International Nuclear Information System (INIS)

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

1979-01-01

Experiments were performed to distinguish between two possible modes of hyperthermia-induced inhibition of thymine base damage excision from the DNA of CHO cells: (1) heat denaturation of excision enzyme(s) or (2) heat-induced alteration of the substrate for damage excision (chromatin). While hyperthermia (45 0 C, 15 min) had no apparent effect on the capacity of the excision enzymes to excise damage from DNA it had a dramatic effect (ca. 80% inhibition) on the ability of chromatin to serve as a substrate for unheated enzymes. These results suggest that hyperthermia-induced radiosensitization of CHO cells may be due primarily to lesions in the cellular chromatin

[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.

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

Involvement of prostaglandins and histamine in radiation-induced temperature responses in rats

International Nuclear Information System (INIS)

Kandasamy, S.B.; Hunt, W.A.

1990-01-01

Exposure of rats to 1-15 Gy of gamma radiation induced hyperthermia, whereas exposure to 20-150 Gy produced hypothermia. Since radiation exposure induced the release of prostaglandins (PGs) and histamine, the role of PGs and histamine in radiation-induced temperature changes was examined. Radiation-induced hyper- and hypothermia were antagonized by pretreatment with indomethacin, a cyclooxygenase inhibitor. Intracerebroventricular administration of PGE2 and PGD2 induced hyper- and hypothermia, respectively. Administration of SC-19220, a specific PGE2 antagonist, attenuated PGE2- and radiation-induced hyperthermia, but it did not antagonize PGD2- or radiation-induced hypothermia. Consistent with an apparent role of histamine in hypothermia, administration of disodium cromoglycate (a mast cell stabilizer), mepyramine (H1-receptor antagonist), or cimetidine (H2-receptor antagonist) attenuated PGD2- and radiation-induced hypothermia. These results suggest that radiation-induced hyperthermia is mediated via PGE2 and that radiation-induced hypothermia is mediated by another PG, possibly PGD2, via histamine

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.)

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

Ultrasonic-resonator-combined apparatus for purifying nuclear aerosol particles

Energy Technology Data Exchange (ETDEWEB)

Hou, Suxia; Zhang, Quanhu; Li, Sufen; Chen, Chen; Su, Xianghua [Xi' an Hi-Tech Institute, Xi' an (China)

2017-12-15

The radiation hazards of radionuclides in the air arising from the storage room of nuclear devices to the operators cannot be ignored. A new ultrasonic-resonator-combined method for purifying nuclear aerosol particles is introduced. To remove particles with diameters smaller than 0.3 μm, an ultrasonic chamber is induced to agglomerate these submicron particles. An apparatus which is used to purify the nuclear aerosol particles is described in the article. The apparatus consists of four main parts: two filtering systems, an ultrasonic chamber and a high-pressure electrostatic precipitator system. Finally, experimental results demonstrated the effectiveness of the implementation of the ultrasonic resonators. The feasibility of the method is proven by its application to the data analysis of the experiments.

Effects of hyperthermia applied to previously irradiated cervical spinal cord in the rat

International Nuclear Information System (INIS)

Sminia, P.; Haveman, J.; Koedoder, C.

1991-01-01

Rat cervical spinal cord was X-ray irradiated at doses of 15, 18, 20 and 26 Gy. Approximately the same part of the spinal cord was heated by means of a 434 MHz microwave applicator 90 days later. After treatment, animals were observed for 18 months, for expression of neurological complications. These could either be result of the heat or of the radiation treatment. The time course showed 3 distinct peaks in the incidence of neurological symptoms. The 1st peak was due to the acute response to hyperthermia. The ED 50 value for neurological complications one day after treatment at 42.3±0.4 o C was 74 ±2 min. Previous X-ray irradiation of spinal cord with 18, 20 and 26 Gy reduced ED 50 to 57±7,65±4 and 55±5 min (12-26% of control), resp. Recovery from heat-induced neurological complications was diminished in previously irradiated animals. The 2nd peak (150-300 days after X-rays) concerned expression of 'early-delayed' radiation damage. Hyperthermia given in 90 days after irradiation did not influence either the percentage of animals with paralysis or the latent period. Neurological symptoms developing after day 300 were due to the late delayed radiation response. Significant difference was not observed in data on paralysis induced by radiation alone or radiation followed by heat. The late radiation-induced minor neurological symptoms, were however, influenced by retreatment with heat. (author). 30 refs., 6 figs., 3 tabs

Ultrasonic testing

Energy Technology Data Exchange (ETDEWEB)

Song, Sung Jin [Sungkwunkwan Univ., Seoul (Korea, Republic of); Jeong, Hyun Jo [Wonkwang Univ., Iksan (Korea, Republic of)

2004-02-15

For the proper performance of ultrasonic testing of steel welded joints, and anisotropic material it is necessary to have sound understanding on the underlying physics. To provide such an understanding, it is beneficial to have simulation tools for ultrasonic testing. In order to address such a need, we develop effective approaches to simulate angle beam ultrasonic testing with a personal computer. The simulation is performed using ultrasonic measurement models based on the computationally efficient multi-Gaussian beams. This reach will describe the developed ultrasonic testing models together with the experimental verification of their accuracy.

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)

Ultrasonic sectional imaging for crack identification. Part 1. Confirmation test of essential factors for ultrasonic imaging

International Nuclear Information System (INIS)

Sasahara, Toshihiko

2008-01-01

Since the first reports of inter-granular stress corrosion crack (IGSCC) in boiling water reactor (BWR) pipe in the 1970s, nuclear power industry has focused considerable attention on service induced crack detection and sizing using ultrasonic examination. In recent years, phased array systems, those reconstruct high quality flaw images at real time are getting to apply for crack detection and sizing. But because the price of phased array systems are expensive for inspection vendors, field application of phased array systems are limited and reliable ultrasonic imaging systems with reasonable price are expected. This paper will discuss cost effective ultrasonic equipment with sectional image (B-scan) presentation as the simplified imaging system for assisting ultrasonic examination personnel. To develop the simplified B-scan imaging system, the frequency characteristics of IGSCC echoes and neighboring geometry echoes such as base-metal to weld interface and inner surface of a pipe are studied. The experimental study confirmed the reflectors have different frequency characteristics and 2MHz is suitable to visualize IGSCC and 5MHz and higher frequency are suitable to reconstruct geometry images. The other study is the amplifier selection for the imaging system. To reconstruct images of IGSCC and geometry echoes, the ultrasonic imaging instrument with linear amplifier has to adjust gain setting to the target. On the other hand, the ultrasonic imaging instrument with logarithmic amplifier can collect and display wider dynamic range on a screen and this wider dynamic range are effective to visualize IGSCC and geometry echoes on a B-scan presentation at a time. (author)

Designing an in-situ ultrasonic nondestructive evaluation system for ultrasonic additive manufacturing

Science.gov (United States)

Nadimpalli, Venkata K.; Nagy, Peter B.

2018-04-01

Ultrasonic Additive Manufacturing (UAM) is a solid-state layer by layer manufacturing process that utilizes vibration induced plastic deformation to form a metallurgical bond between a thin layer and an existing base structure. Due to the vibration based bonding mechanism, the quality of components at each layer depends on the geometry of the structure. In-situ monitoring during and between UAM manufacturing steps offers the potential for closed-loop control to optimize process parameters and to repair existing defects. One interface that is most prone to delamination is the base/build interface and often UAM component height and quality are limited by failure at the base/build interface. Low manufacturing temperatures and favorable orientation of typical interface defects in UAM make ultrasonic NDE an attractive candidate for online monitoring. Two approaches for in-situ NDE are discussed and the design of the monitoring system optimized so that the quality of UAM components is not affected by the addition of the NDE setup. Preliminary results from in-situ ultrasonic NDE indicate the potential to be utilized for online qualification, closed-loop control and offline certification of UAM components.

Time reversal for ultrasonic transcranial surgery and echographic imaging

Science.gov (United States)

Tanter, Mickael; Aubry, Jean-Francois; Vignon, Francois; Fink, Mathias

2005-09-01

High-intensity focused ultrasound (HIFU) is able to induce non-invasively controlled and selective destruction of tissues by focusing ultrasonic beams within organs, analogous to a magnifying glass that concentrates enough sunlight to burn a hole in paper. The brain is an attractive organ in which to perform ultrasonic tissue ablation, but such an application has been hampered by the strong defocusing effect of the skull bone. Our group has been involved in this topic for several years, providing proofs of concept and proposing technological solutions to this problem. Thanks to a high-power time-reversal mirror, presented here are in vivo thermal lesions induced through the skull of 12 sheep. Thermal lesions were confirmed by T2-weighted magnetic resonance post-treatment images and histological examination. These results provide striking evidence that noninvasive ultrasound brain surgery is feasible. A recent approach for high-resolution brain ultrasonic imaging will also be discussed with a skull aberration correction technique based on twin arrays technology. The correction of transcranial ultrasonic images is implemented on a new generation of time-reversal mirrors relying on a fully programmable transmit and receive beamformer.

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)

Response of the microtubular cytoskeleton following hyperthermia as a prognostic indicator of survival of Chinese hamster ovary cells

International Nuclear Information System (INIS)

Coss, Ronald A.; Alden, Mark E.; Wachsberger, Phyllis R.; Smith, Nancy N.

1996-01-01

Purpose: The response of the microtubular (MT) cytoskeleton to hyperthermia was assessed as a prognostic indicator of cytotoxicity. Methods and Materials: Heat-induced collapse and subsequent recovery of the MT system were compared with survival for both nonthermotolerant (NT) and thermotolerant (TT) G1 populations of Chinese hamster ovary (CHO) cells. The response of the MT system was monitored using immunofluorescence staining. The G1 populations of NT and TT cells were heated by submersion in 45.0 and 43.0 deg. C waterbaths. Results: Heat-induced perinuclear collapse of the MT system did not correlate with survival for the NT and TT populations. However, recovery of the organization of the MT cytoskeleton was correlatable with survival. The regression line of survival plotted as a function of MT recovery is fit by: y = -0.43 + 1.03x, r 2 = 0.95 (p < 0.0005). Conclusion: Restoration of the organization of the MT cytoskeleton following hyperthermia may be used as a prognostic indicator of survival of CHO cells heated in G1

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

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.

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.

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

The action of hyperthermia on gene expression in Friend erythroleukemia cells by dimethyl sulfoxide or X-rays

International Nuclear Information System (INIS)

Raaphorst, G.P.; Azzam, E.I.; Einspenner, M.; Ewing, D.; Borsa, J.

1982-02-01

The effect of heat on gene control and on cell killing by X-rays or dimethyl sulfoxide (DMSO) was studied in cultured Friend erythroleukemia cells (FELC). FELC are very sensitive to heat and X-rays in terms of survival, as measured by the colony-forming assay. Heat inactivation kinetics are similar for FELC and Chinese hamster cells. Thermal enhancement of cell inactivation by irradiation was observed at 42.0 and 45.0deg C, and increased as a function of heating time. The simultaneous application of heat and X-rays had a greater effect in terms of cell inactivation. Dimethyl sulfoxide could induce FELC to synthesize hemoglobin, and hyperthermia could inhibit this response. Likewise, hyperthermia could affect induction of heme synthesis by irradiation. Heating before irradiation enhanced production of heme synthesis, whereas heating after irradiation inhibited induction of heme synthesis. The effects of hyperthermia on the survival and gene induction endpoints were compared. Thus, heat can affect both cell survival and gene induction by irradiation or DMSO. The two endpoints of gene induction and survival (proliferative capacity) responded differently, both quantitatively and qualitatively, to heat and X-rays, implying that different cellular targets are affected for each of these endpoints

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.

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)

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.

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)

Piezoelectric Nanotube Array for Broadband High-Frequency Ultrasonic Transducer.

Science.gov (United States)

Liew, Weng Heng; Yao, Kui; Chen, Shuting; Tay, Francis Eng Hock

2018-03-01

Piezoelectric materials are vital in determining ultrasonic transducer and imaging performance as they offer the function for conversion between mechanical and electrical energy. Ultrasonic transducers with high-frequency operation suffer from performance degradation and fabrication difficulty of the demanded piezoelectric materials. Hence, we propose 1-D polymeric piezoelectric nanostructure with controlled nanoscale features to overcome the technical limitations of high-frequency ultrasonic transducers. For the first time, we demonstrate the integration of a well-aligned piezoelectric nanotube array to produce a high-frequency ultrasonic transducer with outstanding performance. We find that nanoconfinement-induced polarization orientation and unique nanotube structure lead to significantly improved piezoelectric and ultrasonic transducing performance over the conventional piezoelectric thin film. A large bandwidth, 126% (-6 dB), is achieved at high center frequency, 108 MHz. Transmission sensitivity of nanotube array is found to be 46% higher than that of the monolithic thin film transducer attributed to the improved electromechanical coupling effectiveness and impedance match. We further demonstrate high-resolution scanning, ultrasonic imaging, and photoacoustic imaging using the obtained nanotube array transducers, which is valuable for biomedical imaging applications in the future.

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.

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)

Argon laser-induced damage in the goldfish (C. auratus) retina following whole-body hyperthermia

Science.gov (United States)

Deaton, Michael A.; Lund, David J.; Schuschereba, Steven T.; Dahlberg, Ann M.; Cowan, Beth L.; Lester, Paul; Odom, Daniel G.

1990-07-01

The heat shock response is a phenomenon common to all cells and is characterized by an increase in the rate of synthesis of intracellular heat shock proteins (HSPs) . The response occurs following rapid transient increases in terrerature sufficient to cause stress but not cell death. HSPs appear to perform protective functions that raise the cell''s tolerance to diverse noxious stimuli. Thus we postulated that we could limit laser-induced retinal darriage through induction of the heat shock -response. Corrmon goldfish (C. auratus) made hyperthermic by immersion in 35C water for 15 minutes and radiolabeled with [355]methionine showed retinal liSPs with apparent molecular weights of 110 90 70 and 35 kilodaltons. To test the protective effects of HSPs against laser injury goldfish were made hyperthermic and 4 and 24 hr later their retinas were irradiated with argon laser light (51 4 . 5 nm spot size at the cornea 3. 0 mm irradiance 125 mW/cm2) . NonhyperLhermic animals served as controls. Following 24 hr of recovery fish were terminated and retinas fixed for histology. Fundus photographs were taken irrunediately after laser exposure . Lesion diameters were measured from fundus photographs and evaluated statistically. The mean retinal lesion diameters of fish not subjected to hyperthermJ. a laser exposed 4 hr post hyperLhermia and laser exposed 24 hr post hyperthermia were 10. 25 1. 4 SD 8. 82 2. 1 SD and 6. 78

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

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

Effect of perphenazine enanthate on open-field test behaviour and stress-induced hyperthermia in domestic sheep.

Science.gov (United States)

Pedernera-Romano, Cecilia; Ruiz de la Torre, José L; Badiella, Llorenç; Manteca, Xavier

2010-01-01

The open-field test (OFT) and stress-induced hyperthermia (SIH) have been used to measure individual differences in fear. The present study has been designed as a pharmacological validation of OFT and SIH as indicators of fear in sheep using perphenazine enanthate (PPZ), a long-acting neuroleptic. Twenty four ewes of two breeds, Lacaune and Ripollesa, were tested in an arena measuring 5mx2.5m. Treatment group received one dose of 1.5mg/kg of PPZ and control group received sterile sesame oil. All animals were tested for 10min and behaviours were recorded. Rectal temperature was measured at the beginning (T1) and at the end (T2) of the test. SIH was defined as the difference between T2 and T1. Sheep were tested on days 1, 2, 3, 4, 7 and 9 after PPZ injection. Variables were analysed using a mixed model. PPZ decreased bleats on days 2, 3, 4 and the SIH response on days 2 and 3. Breed differences were observed. Treated animals showed positive correlations between SIH and bleats; squares entered; attempts to escape and negative correlation between SIH and visits to the food bucket. Our results suggest that behaviour and SIH on the OFT are useful measures of fear in sheep.

Hyperthermia induced after recirculation triggers chronic neurodegeneration in the penumbra zone of focal ischemia in the rat brain

Directory of Open Access Journals (Sweden)

L.A. Favero-Filho

2008-11-01

Full Text Available Chronic neurodegenerative processes have been identified in the rat forebrain after prolonged survival following hyperthermia (HT initiated a few hours after transient global ischemia. Since transient global ischemia and ischemic penumbra share pathophysiological similarities, this study addressed the effects of HT induced after recirculation of focal brain ischemia on infarct size during long survival times. Adult male Wistar rats underwent intra-luminal occlusion of the left middle cerebral artery for 60 min followed by HT (39.0-39.5°C or normothermia. Control procedures included none and sham surgery with and without HT, and middle cerebral artery occlusion alone. Part I: 6-h HT induced at recirculation. Part II: 2-h HT induced at 2-, 6-, or 24-h recirculation. Part III: 2-h HT initiated at recirculation or 6-h HT initiated at 2-, 6- or 24-h recirculation. Survival periods were 7 days, 2 or 6 months. The effects of post-ischemic HT on cortex and striatum were evaluated histopathologically by measuring the area of remaining tissue in the infarcted hemisphere at -0.30 mm from bregma. Six-hour HT initiated from 6-h recirculation caused a significant decrease in the remaining cortical tissue between 7-day (N = 8 and 2-month (N = 8 survivals (98.46 ± 1.14 to 73.62 ± 8.99%, respectively. When induced from 24-h recirculation, 6-h HT caused a significant reduction of the remaining cortical tissue between 2- (N = 8 and 6-month (N = 9 survivals (94.97 ± 5.02 vs 63.26 ± 11.97%, respectively. These data indicate that post-ischemic HT triggers chronic neurodegenerative processes in ischemic penumbra, suggesting that similar fever-triggered effects may annul the benefit of early recirculation in stroke patients over the long-term.

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.

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.

Ultrasonic signature

International Nuclear Information System (INIS)

Borloo, E.; Crutzen, S.

1974-12-01

The unique and tamperproof identification technique developed at Ispra is based on ultrasonic Non-Destructive-Techniques. Reading fingerprints with ultrasonic requires high reproducibility of standard apparatus and transducers. The present report gives an exhaustive description of the ultrasonic technique developed for identification purposes. Different applications of the method are described

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

Radiation/hyperthermia in canine hemangiopericytomas: A large animal model for therapeutic response

International Nuclear Information System (INIS)

Richardson, R.C.; Anderson, V.L.; Voorhees, W.D. III; Blevins, W.E.; Inskeep, T.K.; Janas, W.; Shupe, R.E.; Babbs, C.F.

1984-01-01

X-irradiation followed by microwave induced hyperthermia resulted in a 91% objective response rate in 11 dogs with naturally occurring hemangiopericytomas. The authors used a novel statistical procedure to quantitatively evaluate the clinical behavior of locally invasive, non-metastatic tumors undergoing therapy for control of local disease. Utilizing a small sample size, the procedure demonstrated distribution of the data and classical parametric and non-parametric statistical methods, including setting confidence limits on the population mean and placing tolerance limits on a population percentage. Similarities of canine and human hemangiopericytomas were observed. Application of the statistical methods to human and animal trials were apparent

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

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

Catalase-positive microbial detection by using different ultrasonic parameters

International Nuclear Information System (INIS)

Shukla, S K; Durán, C; Elvira, L

2012-01-01

A method for rapid detection of catalase enzyme activity using ultrasonic parameters is presented in this work. It is based on the detection of the hydrolysis of hydrogen peroxide molecule into water and oxygen induced by the enzyme catalase. A special medium was made to amplify changes produced by catalase enzyme during the hydrolysis process. Enzymatic process can be monitored by means of ultrasonic parameters such as wave amplitude, time of flight (TOF), and backscattering measurements which are sensitive to oxygen bubble production. It is shown that catalase activity of the order of 10 −3 unit/ml can be detected using different ultrasonic parameters. The sensitivity provided by them is discussed.

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.

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

Regulation of body temperature and nociception induced by non-noxious stress in rat.

Science.gov (United States)

Vidal, C; Suaudeau, C; Jacob, J

1984-04-09

The effects of 3 different non-noxious stressors on body temperature (Tb) were investigated in the rat: (1) loose restraint in cylinders, (2) removal of the rats from cylinders, exposure to a novel environment and replacement in cylinders, a stressor called here 'novelty', and (3) gentle holding of the rats by the nape of the neck. Loose restraint and 'novelty' produced hyperthermia. On the contrary, holding induced hypothermia. Hypophysectomy (HX) reduced basal Tb, abolished restraint hyperthermia and reduced both 'novelty' hyperthermia and holding hypothermia. Dexamethasone ( DEXA ) had no effect upon either restraint or novelty hyperthermia but reduced the hypothermia. Naloxone (Nx) produced a slight fall in basal Tb accounting for its reduction of restraint and 'novelty' hyperthermias ; it did not affect holding hypothermia. The inhibitory effects of HX suggest a participation of the pituitary in the hyperthermias ; the neurointermediate lobe would be involved as the hyperthermias were not affected by DEXA , which is known to block the stress-induced release of pituitary secretions from the anterior lobe but not from the neurointermediate lobe. In contrast, substances from the anterior lobe might participate in hypothermia due to holding since it is reduced by HX and DEXA . As to the effects of Nx, endogenous opioids would not be significantly involved in the thermic effects of the stressors used in this study; they might play, if any, only a minor role in the regulation of basal Tb. These results are compared with those previously obtained on nociception using the same non-noxious stressors. It emerges that, depending on the stressor, different types of association between thermoregulation and nociception may occur, i.e. hyperthermia with analgesia, hyperthermia with hyperalgesia and hypothermia with hyperalgesia.

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

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

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.

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....

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.

Decrease of Salmonella typhimurium in skim milk and egg by heat and ultrasonic wave treatment

International Nuclear Information System (INIS)

Wrigley, D.M.; Llorca, N.G.

1992-01-01

Ultrasonic waves induce cavitation which is lethal for many bacteria. When Salmonella typhimurium was suspended in skim milk or brain heart infusion broth and placed in an ultrasonicating water bath, the number of bacteria decreased by 2 to 3 log CFU in a time dependent manner. The killing by ultrasonic waves was enhanced if the menstruum was simultaneously maintained at 50 degrees C. Ultrasonic reduction in S. typhimurium numbers in liquid whole egg ranged from 1-3 log CFU at 50 degrees C. The results indicate that indirect ultrasonic wave treatment is effective in killing Salmonella in some foods

Ultrasonic horn design for ultrasonic machining technologies

Directory of Open Access Journals (Sweden)

Naď M.

2010-07-01

Full Text Available Many of industrial applications and production technologies are based on the application of ultrasound. In many cases, the phenomenon of ultrasound is also applied in technological processes of the machining of materials. The main element of equipments that use the effects of ultrasound for machining technology is the ultrasonic horn – so called sonotrode. The performance of ultrasonic equipment, respectively ultrasonic machining technologies depends on properly designed of sonotrode shape. The dynamical properties of different geometrical shapes of ultrasonic horns are presented in this paper. Dependence of fundamental modal properties (natural frequencies, mode shapes of various sonotrode shapes for various geometrical parameters is analyzed. Modal analyses of the models are determined by the numerical simulation using finite element method (FEM design procedures. The mutual comparisons of the comparable parameters of the various sonotrode shapes are presented.

Efficiency of lipofection combined with hyperthermia in Lewis lung carcinoma cells and a rodent pleural dissemination model of lung carcinoma.

Science.gov (United States)

Okita, Atsushi; Mushiake, Hiroyuki; Tsukuda, Kazunori; Aoe, Motoi; Murakami, Masakazu; Andou, Akio; Shimizu, Nobuyoshi

2004-06-01

We have previously reported that hyperthermia at 41 degrees C enhanced lipofection-mediated gene transduction into cultured cells. In this study, we adapted hyperthermia technique to novel cationic liposome (Lipofectamine 2000) mediated gene transfection into Lewis lung carcinoma cells in vitro and in vivo. In vitro, transfection efficiencies were 38.9+/-3.3% by lipofection alone and 52.1+/-2.6% by lipofection with hyperthermia for 30 min, and 62.5+/-5.5% and 81.4+/-3.2% for 1 h, respectively. Hyperthermia significantly enhanced gene transfection efficiency 1.2-1.4 times more than that with lipofection only. We also evaluated the effect of hyperthermia with a pleural dissemination model of lung carcinoma of mice. We developed a model which was well-tolerated with hyperthermia with lipofection by the mice. In spite of repeated treatments, transfection efficiencies were very low and we could not show the augmentation of gene transfection by hyperthermia. Though Lipofectamine 2000 showed strong gene transduction effect and hyperthermia augmented its effect in vitro, further evaluation is needed to adapt both techniques in vivo.

Differential responses to radiation and hyperthermia of cloned cell lines derived from a single human melanoma xenograft

International Nuclear Information System (INIS)

Rofstad, E.K.; Brustad, T.

1984-01-01

One uncloned and five cloned cell lines were derived from a single human melanoma xenograft. Cells from passages 7-12 were exposed to either radiation or hyperthermia (42.5 0 C, pH = 7.4) under aerobic conditions and the colony forming ability of the cells was assayed in soft agar. The five cloned lines showed individual and characteristic responses to radiation as well as to hyperthermia. The variation in the response to radiation was mainly reflected in the size of the shoulders of the survival curves rather than in the D 0 -values. The variation in the response to hyperthermia was mainly reflected in the terminal slopes of the survival curves. The survival curve of cells from the uncloned line, both when exposed to radiation and hyperthermia, was positioned in the midst of those of the cloned lines. The response of the cloned lines to radiation did not correlate with the response to hyperthermia, indicating that tumor cell subpopulations which are resistant to radiation may respond well to hyperthermia

Effect of hypothermia on cell kinetics and response to hyperthermia and x rays

International Nuclear Information System (INIS)

van Rijn, J.; van den Berg, J.; Kipp, J.B.A.; Schamhart, D.H.J.; van Wijk, R.

1985-01-01

Hyperthermia is a potent radio enhancer. Studies using hypothermia in combination with irradiation have given confusing results due to lack of uniformity in experimental design. This report shows that hypothermia might have potential significance in the treatment of malignant cells with both thermo- and radiotherapy. Reuber H35 hepatoma cells, clone KRC-7 were used to study the effect of hypothermia on cell kinetics and subsequent response to hyperthermia and/or X rays. Cells were incubated at 8.5 0 C or between 25 and 37 0 C for 24 hr prior to hyperthermia or irradiation. Hypothermia caused sensitization to both hyperthermia and X rays. In contrast to the effect of hypothermia on either hyperthermia or X rays alone, thermal radiosensitization was decreased in hypothermically pretreated cells (24 hr at 25 0 C) compared to control cells (37 0 C). The expression of thermotolerance and the rate of development at 37 0 C after an initial heating at 42.5 0 C were not influenced after preincubation at 25 0 C for 24 hr. The expression of thermotolerance for heat or heat plus X rays during incubation at 41 0 C occurred in a significantly smaller number of cells after 24 hr preincubation at 25 0 C. The enhanced thermo- and radiosensitivity in hypothermically treated cells disappeared in approximately 6 hr after return to 37 0 C

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.

An In Vitro Comparative Study of Intracanal Fluid Motion and Wall Shear Stress Induced by Ultrasonic and Polymer Rotary Finishing Files in a Simulated Root Canal Model

OpenAIRE

Koch, Jon; Borg, John; Mattson, Abby; Olsen, Kris; Bahcall, James

2012-01-01

Objective. This in vitro study compared the flow pattern and shear stress of an irrigant induced by ultrasonic and polymer rotary finishing file activation in an acrylic root canal model. Flow visualization analysis was performed using an acrylic canal filled with a mixture of distilled water and rheoscopic fluid. The ultrasonic and polymer rotary finishing file were separately tested in the canal and activated in a static position and in a cyclical axial motion (up and down). Particle moveme...

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.

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)

Ultrasonic Testing of NIF Amplifier FAU Top Plates

International Nuclear Information System (INIS)

Chinn, D.J.; Huber, R.D.; Haskins, J.J.; Rodriguez, J.A.; Souza, P.R.; Le, T.V.

2002-01-01

A key component in the National Ignition Facility (NIF) laser optic system is the amplifier frame assembly unit (FAU). The cast aluminum top plate that supports the FAU is required to withstand loads that would occur during an earthquake with a recurrence period of 1000 years. The stringent seismic requirements placed on the FAU top plate induced a study of the cast aluminum material used in the top plate. Ultrasonic testing was used to aid in characterizing the aluminum material used in the plates. This report documents the work performed using contact ultrasonic testing to characterize the FAU top plate material. The ultrasonic work reported here had 3 objectives: (1) inspect the plate material before cyclic testing conducted at the Pacific Earthquake Engineering Research Center (PEER); (2) determine the overall quality of individual plates; and (3) detect large defects in critical areas of individual plates. Section III, ''Pre-cyclic test inspection'', describes work performed in support of Objective 1. Section IV, ''Ultrasonic field measurements'', describes work performed in support of Objectives 2 and 3

Prediction of strength of wood composite materials using ultrasonic

International Nuclear Information System (INIS)

Mahmoud, M.K.; Emam, A.

2005-01-01

Wood is a biological material integrating a very large variability of its mechanical properties (tensile and compressive), on the two directional longitudinal and transverse Ultrasonic method has been utilized to measure both wood physical and / or wood mechanical properties. The aim of this article is to show the development of ultrasonic technique for quality evaluation of trees, wood material and wood based composites. For quality assessment of these products we discuss the nondestructive evaluation of different factors such as: moisture content, temperature, biological degradation induced by bacterial attack and fungal attack. These techniques were adapted for trees, timber and wood based composites. The present study discusses the prediction of tensile and compressive strength of wood composite materials using ultrasonic testing. Empirical relationships between the tensile properties, compression strength and ultrasonic were proposed. The experimental results indicate the possibility of establishing a relationship between tensile strength and compression values. Moreover, the fractures in tensile and compressive are discussed by photographic

The effects of hyperthermia on the immunomodulatory properties of human umbilical cord vein mesenchymal stem cells (MSCs).

Science.gov (United States)

Hesami, Shilan; Mohammadi, Mehdi; Rezaee, Mohamad Ali; Jalili, Ali; Rahmani, Mohammad Reza

2017-11-01

Hyperthermia can modulate inflammation and the immune response. Based on the recruitment of mesenchymal stem cells (MSCs) to inflamed tissues and the immunomodulatory properties of these cells, the aim of this study was to examine the effects of hyperthermia on the immunomodulatory properties of MSCs in a mixed lymphocyte reaction (MLR). Passages 4-6 of human umbilical cord vein mesenchymal stem cells were co-cultured in a two-way MLR. Cells in the hyperthermia groups were incubated at 41 °C for 45 min. A colorimetric assay was employed to examine the effects of MSCs on cell proliferation. The levels of IL-4 and TNF-α proteins in the cell culture supernatant were measured, and non-adherent cells were used for RNA extraction, which was then used for cDNA synthesis. RT-PCR was utilised to assess levels of IL-10, IL-17A, IL-4, TNF-α, TGF-β1, FOX P 3 , IFN-γ, CXCL12 and β-actin mRNA expression. UCV-MSCs co-cultured in an MLR reduced lymphocyte proliferation at 37 °C, whereas hyperthermia attenuated this effect. Hyperthermia increased expression of IL-10, TGF-β1 and FOXP3 mRNAs in co-culture; however, no effects on IL-17A and IFN-γ were observed, and it reduced CXCL12 expression. In co-culture, IL-4 mRNA and protein increased at 37 °C, an effect that was reduced by hyperthermia. No considerable change in TNF-α mRNA expression was found in hyperthermia-treated cells. Hyperthermia increases cell proliferation of the peripheral blood mononuclear cells and modifies the cytokine profile in the presence of UCV-MSCs.

The role of hyperthermia and metabolism as mechanisms of tolerance to methamphetamine neurotoxicity.

Science.gov (United States)

Johnson-Davis, Kamisha L; Fleckenstein, Annette E; Wilkins, Diana G

2003-12-15

Pretreatment with multiple methamphetamine injections prior to a high-dose methamphetamine challenge administration can attenuate long-term deficits in striatal and hippocampal serotonin content caused by the stimulant. The present data extend previous findings by demonstrating that rats pretreated with escalating doses methamphetamine did not exhibit dopamine deficits in the striatum, nor serotonin deficits in striatal, frontal cortical, or hippocampal tissues, 7 days after a challenge methamphetamine administration. This protection was not due to attenuation of methamphetamine-induced hyperthermia or altered brain methamphetamine concentrations. These data differ from previous findings thereby highlighting that different mechanisms contribute to the tolerance of the neurotoxic effects.

Comparative Study of Ultrasonication-Induced and Naturally Self-Assembled Silk Fibroin-Wool Keratin Hydrogel Biomaterials.

Science.gov (United States)

Vu, Trang; Xue, Ye; Vuong, Trinh; Erbe, Matthew; Bennet, Christopher; Palazzo, Ben; Popielski, Lucas; Rodriguez, Nelson; Hu, Xiao

2016-09-07

This study reports the formation of biocompatible hydrogels using protein polymers from natural silk cocoon fibroins and sheep wool keratins. Silk fibroin protein contains β-sheet secondary structures, allowing for the formation of physical cross-linkers in the hydrogels. Comparative studies were performed on two groups of samples. In the first group, ultrasonication was used to induce a quick gelation of a protein aqueous solution, enhancing the ability of Bombyx mori silk fibroin chains to quickly entrap the wool keratin protein molecules homogenously. In the second group, silk/keratin mixtures were left at room temperature for days, resulting in naturally-assembled gelled solutions. It was found that silk/wool blended solutions can form hydrogels at different mixing ratios, with perfectly interconnected gel structure when the wool content was less than 30 weight percent (wt %) for the first group (ultrasonication), and 10 wt % for the second group (natural gel). Differential scanning calorimetry (DSC) and temperature modulated DSC (TMDSC) were used to confirm that the fibroin/keratin hydrogel system was well-blended without phase separation. Fourier transform infrared spectroscopy (FTIR) was used to investigate the secondary structures of blended protein gels. It was found that intermolecular β-sheet contents significantly increase as the system contains more silk for both groups of samples, resulting in stable crystalline cross-linkers in the blended hydrogel structures. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to analyze the samples' characteristic morphology on both micro- and nanoscales, which showed that ultrasonic waves can significantly enhance the cross-linker formation and avoid phase separation between silk and keratin molecules in the blended systems. With the ability to form cross-linkages non-chemically, these silk/wool hydrogels may be economically useful for various biomedical applications, thanks to the

Comparative Study of Ultrasonication-Induced and Naturally Self-Assembled Silk Fibroin-Wool Keratin Hydrogel Biomaterials

Directory of Open Access Journals (Sweden)

Trang Vu

2016-09-01

Full Text Available This study reports the formation of biocompatible hydrogels using protein polymers from natural silk cocoon fibroins and sheep wool keratins. Silk fibroin protein contains β-sheet secondary structures, allowing for the formation of physical cross-linkers in the hydrogels. Comparative studies were performed on two groups of samples. In the first group, ultrasonication was used to induce a quick gelation of a protein aqueous solution, enhancing the ability of Bombyx mori silk fibroin chains to quickly entrap the wool keratin protein molecules homogenously. In the second group, silk/keratin mixtures were left at room temperature for days, resulting in naturally-assembled gelled solutions. It was found that silk/wool blended solutions can form hydrogels at different mixing ratios, with perfectly interconnected gel structure when the wool content was less than 30 weight percent (wt % for the first group (ultrasonication, and 10 wt % for the second group (natural gel. Differential scanning calorimetry (DSC and temperature modulated DSC (TMDSC were used to confirm that the fibroin/keratin hydrogel system was well-blended without phase separation. Fourier transform infrared spectroscopy (FTIR was used to investigate the secondary structures of blended protein gels. It was found that intermolecular β-sheet contents significantly increase as the system contains more silk for both groups of samples, resulting in stable crystalline cross-linkers in the blended hydrogel structures. Scanning electron microscopy (SEM and atomic force microscopy (AFM were used to analyze the samples’ characteristic morphology on both micro- and nanoscales, which showed that ultrasonic waves can significantly enhance the cross-linker formation and avoid phase separation between silk and keratin molecules in the blended systems. With the ability to form cross-linkages non-chemically, these silk/wool hydrogels may be economically useful for various biomedical applications

Ultrasonic inspection

International Nuclear Information System (INIS)

Satittada, Gannaga

1984-01-01

Ultrasonic inspection is one of the most widely used methods for nondestructive inspection. The beam of high-frequency sound wave, ultrasonic wave, is introduced into the material. It travels through the material with some attendant loss of energy and can be reflected at interfaces. The reflected beam is detected and analyzed. Ultrasonic inspection is used to detect flaws in metal parts as well as in welded, brazed and bonded joints during research work and developing production and service. It is also used to detect and locate porosity, pipe, and flakes. In addition, it can be used for the measurement of metal thickness. Ultrasonic inspection is therefore used for quality control and material inspection in all major industries

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

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

Changes in tumor oxygenation during a combined treatment with fractionated irradiation and hyperthermia: an experimental study.

Science.gov (United States)

Zywietz, F; Reeker, W; Kochs, E

1997-01-01

To determine the influence of adjuvant hyperthermia on the oxygenation status of fractionated irradiated tumors. Oxygen partial pressure (pO2) in rat rhabdomyosarcomas (R1H) was measured sequentially at weekly intervals during a fractionated irradiation with 60Co-gamma-rays (60 Gy/20f/4 weeks) in combination with local hyperthermia (8 f(HT) at 43 degrees C, 1 h/4 weeks). Tumors were heated twice weekly with a 2450 MHz microwave device at 43 degrees C, 1 h starting 10 min after irradiation. The pO2 measurements (pO2-histograph, Eppendorf, Germany) were performed in anesthetized animals during mechanical ventilation and in hemodynamic steady state. All tumor pO2 measurements were correlated to measurements of the arterial oxygen partial pressure (paO2) determined by a blood gas analyzer. The oxygenation status of R1H tumors decreased continuously from the start of the combined treatment, with increasing radiation dose and number of heat fractions. In untreated controls a median tumor pO2 of 23 +/- 2 mmHg (mean +/- SEM) was measured. Tumor pO2 decreased to 11 +/- 2 mmHg after 30 Gy + 4 HT (2 weeks), and to 6 +/- 2 mmHg after 60 Gy + 8HT (4 weeks). The increase in the frequency of pO2-values below 5 mmHg and the decrease in the range of the pO2 histograms [delta p(10/90)] further indicated that tumor hypoxia increased relatively rapidly from the start of combined treatment. After 60 Gy + 8HT 48 +/- 5% (mean +/- SEM) of the pO2-values recorded were below 5 mmHg. These findings suggest that adjuvant hyperthermia to radiotherapy induces greater changes in tumor oxygenation than radiation alone [cf. (39)]. This might be of importance for the temporary application of hyperthermia in the course of a conventional radiation treatment.

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

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

Ultrasonic mammography

International Nuclear Information System (INIS)

Hueneke, B.

1982-01-01

608 women are examined by means of ultrasonic mammography during the period of 1 year. 432 patients were examined with the compound method with the U.I. Octoson, a water tank scanner, and 176 patients with the real time method with a directly connected linear-array-scanner. The following results were obtained at the end of the examination period: In the ultrasonic and also in the X-ray mammogram tumour diameters can be determined with an error rate of +- 30%. In the diagnosing of carcinomas, a significant dependence of the exactness on the sice of the tumour is found for the combination of the five methods tested (clinical examination, X-ray mammography, ultrasonic mammography, thermography, cytology). Classifying the individual methods with regard to their exactness, X-ray mammography ranks in front of ultrasonic mammography. Mastopathic changes in the breast can be screened by means of ultrasonic mammography. The structure of the changes can be determined more exactly than with an X-ray picture which is due to the possibility of differentiating solid and cystic structures. In diagnosing fibro-adenomas and establishing diagnoses on young women with dense gland bodies, ultrasonic mammography is superior to radiology both in the ability of screening a finding of a fibro-adenoma (US=88%, X-ray=75%) and in the possibility of classifying it as ''more benign than malignant''. (orig./MG) [de

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.

Altered lipid homeostasis in Sertoli cells stressed by mild hyperthermia.

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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.

Ultrasonic physics

CERN Document Server

Richardson, E G

1962-01-01

Ultrasonic Physics, Second Edition, provides an introduction to the fundamental principles of ultrasonic physics. The book opens with a discussion of the sources of ultrasound. This is followed by separate chapters on the properties and detection of ultrasonic radiation; measurement of propagation constants, i.e., the velocity and absorption, of ultrasound; ultrasound propagation in gases, liquids, and solids; and ultrasound propagation in aerosols, suspensions, and emulsions. The final chapter covers miscellaneous physical and physico-chemical actions, including dispersion and coagulation of

‘Smart’ gold nanoshells for combined cancer chemotherapy and hyperthermia

International Nuclear Information System (INIS)

Liang, Zhongshi; Xie, Yegui; Liu, Shunying; Li, Xingui

2014-01-01

Nanomaterials that circulate in the body have great potential in the diagnosis and treatment of diseases. Here we report that ‘smart’ gold nanoshells can carry a drug payload, and that their intrinsic near-infrared (NIR) plasmon resonance enables the combination of chemotherapeutic and hyperthermia therapies. The ‘smart’ gold nanoshells (named DOX/A54@GNs) consist of (a) gold nanoshells (GNs) with NIR plasmon resonance, which not only act as nanoblocks but also produce local heat to allow hyperthermia; (b) an anticancer drug, doxorubicin (DOX), which was conjugated onto the nanoblocks by pH-dependent biodegradable copolymer thiol poly(ethylene glycol) derivatives via carbamate linkage; and (c) the targeting peptide A54 (AGKGTPSLETTP) to facilitate its orientation to liver cancer cells and enhance cellular uptake. The conjugated DOX was released from the DOX/A54@GNs much more rapidly in an acidic environment (pH 5.3) than in a neutral environment (pH 7.4), which is a desirable characteristic for intracellular tumor drug release. DOX-modified GNs showed pH-dependent release behavior, and the in vitro cell uptake experiment using ICP-AES and microscopy showed greater internalization of A54-modified GNs in the human liver cancer cell line BEL-7402 than of those without A54. Flow cytometry and fluoroscopy analysis were conducted to reveal the enhanced cell apoptosis caused by the A54-modified GNs under combined chemotherapeutic and hyperthermia therapies. These results imply that DOX/A54@GNs could be used as a multifunctional nanomaterial system with pH-triggered drug-releasing properties for tumor-targeted chemotherapy and hyperthermia. (paper)

Effect of hyperthermia on epithelial microneoplastic cell populations induced by irradiation of rat skin

International Nuclear Information System (INIS)

Gragtmans, N.J.; McGregor, J.F.

1983-01-01

Two groups of male rats of the Charles River CD stock received a dose of 1,600 rad beta-radiation (700 rad/min) on the skin of the dorsum. Two months later, the site of irradiation of one of the groups was treated with hyperthermia at 44 degrees C for 2.5 minutes. A third control group received only the hyperthermic treatment. Over 90% of the animals in the 2 irradiated groups developed skin tumors (benign and malignant epithelial) at the irradiated site. There was no significant difference between these 2 groups in incidence of animals with tumors, incidence of tumors, distribution of tumor types, or rate of tumor appearance. The incidence of animals with tumors in the control group was less than 4% at any time

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

Studies on the mechanisms underlying amiloride enhancement of 3,4-methylenedioxymethamphetamine-induced serotonin depletion in rats.

Science.gov (United States)

Goñi-Allo, Beatriz; Puerta, Elena; Hervias, Isabel; Di Palma, Richard; Ramos, Maria; Lasheras, Berta; Aguirre, Norberto

2007-05-21

Amiloride and several of its congeners known to block the Na(+)/Ca(2+) and/or Na(+)/H(+) antiporters potentiate methamphetamine-induced neurotoxicity without altering methamphetamine-induced hyperthermia. We now examine whether amiloride also exacerbates 3,4-methylenedioxymethamphetamine (MDMA)-induced long-term serotonin (5-HT) loss in rats. Amiloride (2.5 mg/kg, every 2 h x 3, i.p.) given at ambient temperature 30 min before MDMA (5 mg/kg, every 2 h x 3, i.p.), markedly exacerbated long-term 5-HT loss. However, in contrast to methamphetamine, amiloride also potentiated MDMA-induced hyperthermia. Fluoxetine (10 mg/kg i.p.) completely protected against 5-HT depletion caused by the MDMA/amiloride combination without significantly altering the hyperthermic response. By contrast, the calcium channel antagonists flunarizine or diltiazem did not afford any protection. Findings with MDMA and amiloride were extended to the highly selective Na(+)/H(+) exchange inhibitor dimethylamiloride, suggesting that the potentiating effects of amiloride are probably mediated by the blockade of Na(+)/H(+) exchange. When the MDMA/amiloride combination was administered at 15 degrees C hyperthermia did not develop and brain 5-HT concentrations remained unchanged 7 days later. Intrastriatal perfusion of MDMA (100 microM for 8 h) in combination with systemic amiloride caused a small depletion of striatal 5-HT content in animals made hyperthermic but not in the striatum of normothermic rats. These data suggest that enhancement of MDMA-induced 5-HT loss caused by amiloride or dimethylamiloride depends on their ability to enhance MDMA-induced hyperthermia. We hypothesise that blockade of Na(+)/H(+) exchange could synergize with hyperthermia to render 5-HT terminals more vulnerable to the toxic effects of MDMA.

A case report of suspected malignant hyperthermia where patient survived the episode.

Science.gov (United States)

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 <5% in the presence of standard care. In India, there is no center where in vitro halothane caffeine contraction test is performed to confirm diagnosis in suspected cases. Second, dantrolene drug of choice for this condition is not freely available in market in India and is stored only in some hospitals in few major cities. Among the cases reported of suspected of malignant hyperthermia in India almost 50% have survived the condition despite nonavailability of dantrolene emphasizing role of early detection and aggressive management in these cases.

A case report of suspected malignant hyperthermia where patient survived the episode

Directory of Open Access Journals (Sweden)

Asif Iqbal

2017-01-01

Full Text Available 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 <5% in the presence of standard care. In India, there is no center where in vitro halothane caffeine contraction test is performed to confirm diagnosis in suspected cases. Second, dantrolene drug of choice for this condition is not freely available in market in India and is stored only in some hospitals in few major cities. Among the cases reported of suspected of malignant hyperthermia in India almost 50% have survived the condition despite nonavailability of dantrolene emphasizing role of early detection and aggressive management in these cases.

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

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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.

Embedded fiber optic ultrasonic sensors and generators

Science.gov (United States)

Dorighi, John F.; Krishnaswamy, Sridhar; Achenbach, Jan D.

1995-04-01

Ultrasonic sensors and generators based on fiber-optic systems are described. It is shown that intrinsic fiber optic Fabry-Perot ultrasound sensors that are embedded in a structure can be stabilized by actively tuning the laser frequency. The need for this method of stabilization is demonstrated by detecting piezoelectric transducer-generated ultrasonic pulses in the presence of low frequency dynamic strains that are intentionally induced to cause sensor drift. The actively stabilized embedded fiber optic Fabry-Perot sensor is also shown to have sufficient sensitivity to detect ultrasound that is generated in the interior of a structure by means of a high-power optical fiber that pipes energy from a pulsed laser to an embedded generator of ultrasound.

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

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

Association of acute adverse effects with high local SAR induced in the brain from prolonged RF head and neck hyperthermia

International Nuclear Information System (INIS)

Adibzadeh, F; Verhaart, R F; Rijnen, Z; Franckena, M; Van Rhoon, G C; Paulides, M M; Verduijn, G M; Fortunati, V

2015-01-01

To provide an adequate level of protection for humans from exposure to radio-frequency (RF) electromagnetic fields (EMF) and to assure that any adverse health effects are avoided. The basic restrictions in terms of the specific energy absorption rate (SAR) were prescribed by IEEE and ICNIRP. An example of a therapeutic application of non-ionizing EMF is hyperthermia (HT), in which intense RF energy is focused at a target region. Deep HT in the head and neck (H and N) region involves inducing energy at 434 MHz for 60 min on target. Still, stray exposure of the brain is considerable, but to date only very limited side-effects were observed. The objective of this study is to investigate the stringency of the current basic restrictions by relating the induced EM dose in the brain of patients treated with deep head and neck (H and N) HT to the scored acute health effects. We performed a simulation study to calculate the induced peak 10 g spatial-averaged SAR (psSAR 10g ) in the brains of 16 selected H and N patients who received the highest SAR exposure in the brain, i.e. who had the minimum brain-target distance and received high forwarded power during treatment. The results show that the maximum induced SAR in the brain of the patients can exceed the current basic restrictions (IEEE and ICNIRP) on psSAR 10g for occupational environments by 14 times. Even considering the high local SAR in the brain, evaluation of acute effects by the common toxicity criteria (CTC) scores revealed no indication of a serious acute neurological effect. In addition, this study provides pioneering quantitative human data on the association between maximum brain SAR level and acute adverse effects when brains are exposed to prolonged RF EMF. (paper)

Gold nanorod-mediated hyperthermia enhances the efficacy of HPMA copolymer-90Y conjugates in treatment of prostate tumors

International Nuclear Information System (INIS)

Buckway, Brandon; Frazier, Nick; Gormley, Adam J.; Ray, Abhijit; Ghandehari, Hamidreza

2014-01-01

Introduction: The treatment of prostate cancer using a radiotherapeutic 90 Y labeled N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer can be enhanced with localized tumor hyperthermia. An 111 In labeled HPMA copolymer system for single photon emission computerized tomography (SPECT) was developed to observe the biodistribution changes associated with hyperthermia. Efficacy studies were conducted in prostate tumor bearing mice using the 90 Y HPMA copolymer with hyperthermia. Methods: HPMA copolymers containing 1, 4, 7, 10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) were synthesized by reversible addition-fragmentation transfer (RAFT) copolymerization and subsequently labeled with either 111 In for imaging or 90 Y for efficacy studies. Radiolabel stability was characterized in vitro with mouse serum. Imaging and efficacy studies were conducted in DU145 prostate tumor bearing mice. Imaging was performed using single photon emission computerized tomography (SPECT). Localized mild tumor hyperthermia was achieved by plasmonic photothermal therapy using gold nanorods. Results: HPMA copolymer-DOTA conjugates demonstrated efficient labeling and stability for both radionuclides. Imaging analysis showed a marked increase of radiolabeled copolymer within the hyperthermia treated prostate tumors, with no significant accumulation in non-targeted tissues. The greatest reduction in tumor growth was observed in the hyperthermia treated tumors with 90 Y HPMA copolymer conjugates. Histological analysis confirmed treatment efficacy and safety. Conclusion: HPMA copolymer-DOTA conjugates radiolabeled with both the imaging and treatment radioisotopes, when combined with hyperthermia can serve as an image guided approach for efficacious treatment of prostate tumors

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

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

Effect of Ultrasonic Frequency on Lactic Acid Fermentation Promotion by Ultrasonic Irradiation

Science.gov (United States)

Shimada, Tadayuki; Ohdaira, Etsuzo; Masuzawa, Nobuyoshi

2004-05-01

The authors have been researching the promotion of lactic acid fermentation by ultrasonic irradiation. In the past research, it was proven that ultrasonic irradiation is effective in the process of fermentation, and the production of yoghurt and kefir was promoted. In this study, the effect of the ultrasonic frequency in this fermentation process was examined. In the frequency range of this study, it was found that the action of fermentation promotion was exponentially proportionate to the irradiated ultrasonic frequency.

Correlation vs. Causation: The Effects of Ultrasonic Melt Treatment on Cast Metal Grain Size

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J. B. Ferguson

2014-10-01

Full Text Available Interest in ultrasonic treatment of liquid metal has waxed and waned for nearly 80 years. A review of several experiments representative of ultrasonic cavitation treatment of Al and Mg alloys shows that the theoretical mechanisms thought to be responsible for grain refinement are (1 cavitation-induced increase in melting temperature predicted by the Clausius-Clapeyron equation and (2 cavitation-induced wetting of otherwise unwetted insoluble particles. Neither of these theoretical mechanisms can be directly confirmed by experiment, and though they remain speculative, the available literature generally assumes that one or the other or both mechanisms are active. However, grain size is known to depend on temperature of the liquid, temperature of the mold, and cooling rate of the entire system. From the reviewed experiments, it is difficult to isolate temperature and cooling rate effects on grain size from the theoretical effects. Ultrasonic treatments of Al-A356 were carried out to isolate such effects, and though it was found that ultrasound produced significant grain refinement, the treatments also significantly chilled the liquid and thereby reduced the pouring temperature. The grain sizes attained closely correlated with pouring temperature suggesting that ultrasonic grain refinement is predominantly a result of heat removal by the horn and ultrasonic stirring.

Malignant hyperthermia

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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

Caffeine promotes hyperthermia and serotonergic loss following co-administration of the substituted amphetamines, MDMA ("Ecstasy") and MDA ("Love").

Science.gov (United States)

McNamara, Ruth; Kerans, Aoife; O'Neill, Barry; Harkin, Andrew

2006-01-01

The present study determined the effect of caffeine co-administration on the core body temperature response and long-term serotonin (5-HT) loss induced by methylenedioxymethamphetamine (MDMA; "Ecstasy") and its metabolite methylenedioxyamphetamine (MDA; "Love") to rats. In group-housed animals, caffeine (10 mg/kg) enhanced the acute toxicity of MDMA (15 mg/kg) and MDA (7.5 mg/kg), resulting in an exaggerated hyperthermic response (+2 degrees C for 5 h following MDMA and +1.5 degrees C for 3 h following MDA) when compared to MDMA (+1 degree C for 3 h) and MDA (+1 degree C for 1 h) alone. Co-administration of caffeine with MDMA or MDA was also associated with increased lethality. To reduce the risk of lethality, doses of MDMA and MDA were reduced in further experiments and the animals were housed individually. To examine the effects of repeated administration, animals received MDMA (10 mg/kg) or MDA (5 mg/kg) with or without caffeine (10 mg/kg) twice daily for 4 consecutive days. MDMA and MDA alone induced hypothermia (fall of 1 to 2 degrees C) over the 4 treatment days. Co-administration of caffeine with MDMA or MDA resulted in hyperthermia (increase of up to 2.5 degrees C) following acute administration compared to animals treated with caffeine or MDMA/MDA alone. This hyperthermic response to caffeine and MDMA was not observed with repeated administration, unlike caffeine + MDA, where hyperthermia was obtained over the 4 day treatment period. In addition, 4 weeks after the last treatment, co-administration of caffeine with MDA (but not MDMA) induced a reduction in 5-HT and 5-hydroxyindole acetic acid (5-HIAA) concentrations in frontal cortex (to 61% and 58% of control, respectively), hippocampus (48% and 60%), striatum (79% and 64%) and amygdala (63% and 37%). However, when caffeine (10 mg/kg) and MDMA (2.5 mg/kg) were co-administered four times daily for 2 days to group-housed animals, both hyperthermia and hippocampal 5-HT loss were observed (reduced to 68% of

Electromagnetic ultrasonic guided waves

CERN Document Server

Huang, Songling; Li, Weibin; Wang, Qing

2016-01-01

This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.

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

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

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.

Exercise-induced hyperthermia syndrome (canine stress syndrome in four related male English springer spaniels

Directory of Open Access Journals (Sweden)

Thrift E

2017-09-01

Full Text Available Elizabeth Thrift,1 Justin A Wimpole,2 Georgina Child,2 Narelle Brown,1 Barbara Gandolfi,3 Richard Malik4 1Animal Referral Hospital, 2Small Animal Specialist Hospital, Sydney, NSW, Australia; 3Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA; 4Centre for Veterinary Education, University of Sydney, Sydney, NSW, Australia Objective: This retrospective study describes the signalment, clinical presentation, diagnostic findings, and mode of inheritance in four young male English springer spaniel dogs with presumptive canine stress syndrome.Materials and methods: Appropriate cases were located through medical searches of medical records of two large private referral centers. Inclusion criteria comprised of English springer spaniel dogs with tachypnea and hyperthermia that subsequently developed weakness or collapse, with or without signs of hemorrhage, soon after a period of mild-to-moderate exercise. The pedigrees of the four affected dogs, as well as eleven related English springer spaniels, were then analyzed to determine a presumptive mode of genetic inheritance.Results: Four dogs met the inclusion criteria. All four were male, suggesting the possibility of a recessive sex-linked heritable disorder. Pedigree analysis suggests that more dogs may be potentially affected, although these dogs may have never had the concurrent triggering drug/activity/event to precipitate the clinical syndrome. There was complete resolution of clinical signs in three of the four dogs with aggressive symptomatic and supportive therapy, with one dog dying during treatment.Conclusion: Dogs with canine stress syndrome have the potential for rapid recovery if treated aggressively and the complications of the disease (eg, coagulopathy are anticipated. All four dogs were male, suggesting the possibility of a recessive sex-linked mode of inheritance. Further genetic analyses should be strongly considered by those

Intramembrane Cavitation as a Predictive Bio-Piezoelectric Mechanism for Ultrasonic Brain Stimulation

Directory of Open Access Journals (Sweden)

Michael Plaksin

2014-01-01

Full Text Available Low-intensity ultrasonic waves can remotely and nondestructively excite central nervous system (CNS neurons. While diverse applications for this effect are already emerging, the biophysical transduction mechanism underlying this excitation remains unclear. Recently, we suggested that ultrasound-induced intramembrane cavitation within the bilayer membrane could underlie the biomechanics of a range of observed acoustic bioeffects. In this paper, we show that, in CNS neurons, ultrasound-induced cavitation of these nanometric bilayer sonophores can induce a complex mechanoelectrical interplay leading to excitation, primarily through the effect of currents induced by membrane capacitance changes. Our model explains the basic features of CNS acoustostimulation and predicts how the experimentally observed efficacy of mouse motor cortical ultrasonic stimulation depends on stimulation parameters. These results support the hypothesis that neuronal intramembrane piezoelectricity underlies ultrasound-induced neurostimulation, and suggest that other interactions between the nervous system and pressure waves or perturbations could be explained by this new mode of biological piezoelectric transduction.

Ultrasonic viewing device

International Nuclear Information System (INIS)

Ito, Juro.

1979-01-01

Purpose: To improve the safety of reactor operation by enabling to detect the states and positions of fuel assemblies over a wide range with a set of ultrasonic viewing device comprising a rotatable ultrasonic transmitter-receiver and a reflector mounted with an adjustable angle. Constitution: A driving portion for a ultrasonic viewing device is provided to a rotary plug closing the opening of a reactor vessel and a guide pipe suspending below the coolant level is provided to the driving portion. An ultrasonic transmitter-receiver is provided at the end of the holder tube in the guide pipe. A reflector is provided at the upper position of the reactor core so as to correspond to the ultrasonic transmitter-receiver. The ultrasonic transmitter-receiver, positioned by the driving portion, performs horizontal movement for scanning the entire surface of the top of the reactor core, as well as vertical movement covering the gap between the upper mechanism on the reactor and the reactor core, whereby the confirmation for the separation of the control rod and the detection for the states of the reactor core can be conducted by the reflection waves from the reflector. (Moriyama, K.)

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.

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)

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].

Hyperthermia with rotating magnetic nanowires inducing heat into tumor by fluid friction

Energy Technology Data Exchange (ETDEWEB)

Egolf, Peter W.; Pawlowski, Anne-Gabrielle; Tsague, Paulin; Marco, Bastien de; Bovy, William; Tucev, Sinisa [Institute of Thermal Sciences and Engineering, University of Applied Sciences of Western Switzerland, CH 1401 Yverdon-les-Bains (Switzerland); Shamsudhin, Naveen, E-mail: snaveen@ethz.ch; Pané, Salvador; Pokki, Juho; Ansari, M. H. D.; Nelson, Bradley J. [Multi-Scale Robotics Lab, Institute of Robotics and Intelligent Systems, ETH Zurich, CH 8092 Zurich (Switzerland); Vuarnoz, Didier [Ecole Polytechnique Fédérale de Lausanne (EPFL), EPFL Fribourg, CH 1701 Fribourg (Switzerland)

2016-08-14

A magnetic hyperthermia cancer treatment strategy that does not operate by means of conventional heating mechanisms is presented. The proposed approach consists of injecting a gel with homogeneously distributed magnetic nanowires into a tumor. Upon the application of a low-frequency rotating or circularly polarized magnetic field, nanowires spin around their center of viscous drag due to torque generated by shape anisotropy. As a result of external rotational forcing and fluid friction in the nanoparticle's boundary layer, heating occurs. The nanowire dynamics is theoretically and experimentally investigated, and different feasibility proofs of the principle by physical modeling, which adhere to medical guidelines, are presented. The magnetic nanorotors exhibit rotations and oscillations with quite a steady center of gravity, which proves an immobile behavior and guarantees a time-independent homogeneity of the spatial particle distribution in the tumor. Furthermore, a fluid dynamic and thermodynamic heating model is briefly introduced. This model is a generalization of Penne's model that for this method reveals theoretic heating rates that are sufficiently high, and fits well into medical limits defined by present standards.

Ultrasonic control of ceramic membrane fouling: Effect of particle characteristics.

Science.gov (United States)

Chen, Dong; Weavers, Linda K; Walker, Harold W

2006-02-01

In this study, the effect of particle characteristics on the ultrasonic control of membrane fouling was investigated. Ultrasound at 20 kHz was applied to a cross-flow filtration system with gamma-alumina membranes in the presence of colloidal silica particles. Experimental results indicated that particle concentration affected the ability of ultrasound to control membrane fouling, with less effective control of fouling at higher particle concentrations. Measurements of sound wave intensity and images of the cavitation region indicated that particles induced additional cavitation bubbles near the ultrasonic source, which resulted in less turbulence reaching the membrane surface and subsequently less effective control of fouling. When silica particles were modified to be hydrophobic, greater inducement of cavitation bubbles near the ultrasonic source occurred for a fixed concentration, also resulting in less effective control of fouling. Particle size influenced the cleaning ability of ultrasound, with better permeate recovery observed with larger particles. Particle size did not affect sound wave intensity, suggesting that the more effective control of fouling by large particles was due to greater lift and cross-flow drag forces on larger particles compared to smaller particles.

Heat-induced alterations in the cell nucleus

International Nuclear Information System (INIS)

Kampinga, H.H.

1989-01-01

Hyperthermia may kill eukaryotic cells and may also enhance the radiosensitivity of those cells that survive the heat treatment. Clinically, the possible use of hyperthermia as an adjuvant in the radiotherapeutic treatment of cancer needs the understanding of mechanisms that underlay heat-induced cell death and radiosensitization. By in vitro heating of established human (HeLaS3) and rodent (Ehrlich Ascites Tumor and LM fibroblast) cell lines, both killing and radiosensitization were investigated. (author). 1067 refs.; 76 figs.; 19 tabs

Investigations on Tl-2223 thin films fabricated through ultrasonic ...

Indian Academy of Sciences (India)

Unknown

converted into mist by an ultrasonic nebulizer operating at a frequency of ~ 106 Hz. This mist ... TBCCO system is formed at ~ 890°C, we have used this as the thalliation .... nucleation and growth kinetics induced by highly mobile. Ag particles.

Radial vibration and ultrasonic field of a long tubular ultrasonic radiator.

Science.gov (United States)

Shuyu, Lin; Zhiqiang, Fu; Xiaoli, Zhang; Yong, Wang; Jing, Hu

2013-09-01

The radial vibration of a metal long circular tube is studied analytically and its electro-mechanical equivalent circuit is obtained. Based on the equivalent circuit, the radial resonance frequency equation is derived. The theoretical relationship between the radial resonance frequency and the geometrical dimensions is studied. Finite element method is used to simulate the radial vibration and the radiated ultrasonic field and the results are compared with those from the analytical method. It is concluded that the radial resonance frequency for a solid metal rod is larger than that for a metal tube with the same outer radius. The radial resonance frequencies from the analytical method are in good agreement with those from the numerical method. Based on the acoustic field analysis, it is concluded that the long metal tube with small wall thickness is superior to that with large wall thickness in producing radial vibration and ultrasonic radiation. Therefore, it is expected to be used as an effective radial ultrasonic radiator in ultrasonic sewage treatment, ultrasonic antiscale and descaling and other ultrasonic liquid handling applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Ultrasonic splitting of oil-in-water emulsions

DEFF Research Database (Denmark)

Hald, Jens; König, Ralf; Benes, Ewald

1999-01-01

Standing resonant ultrasonic wave fields can be utilized for liquid–liquid separation of the dispersed particles and the fluid caused by the acoustic radiation pressure and the induced particle agglomeration or coagulation/coalescence process. For the splitting of oil-in-water emulsions, the avai......Standing resonant ultrasonic wave fields can be utilized for liquid–liquid separation of the dispersed particles and the fluid caused by the acoustic radiation pressure and the induced particle agglomeration or coagulation/coalescence process. For the splitting of oil-in-water emulsions......, the available piezoelectric composite transducer technology was improved and a dedicated resonator with crossed plane wave sonication geometry has been developed. The resonator chamber is entirely made of aluminium or tempax glass and the PZT piezoceramic transducer delivers an acoustic energy flow density...... of up to 24 W/cm2 into the sonication volume. The chosen resonance frequency is kept stable by automatic frequency control utilizing the maximum true power criterion. Physically and chemically well-defined low and high density pure laboratory and also industrially used cooling-lubricating oil...

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)

Ultrasonic decontamination robot

International Nuclear Information System (INIS)

Patenaude, R.S.

1984-01-01

An ultrasonic decontamination robot removes radioactive contamination from the internal surface of the inlet and outlet headers, divider plate, tube sheet, and lower portions of tubes of a nuclear power plant steam generator. A programmable microprocessor controller guides the movement of a robotic arm mounted in the header manway. An ultrasonic transducer having a solvent delivery subsystem through which ultrasonic action is achieved is moved by the arm over the surfaces. A solvent recovery suction tube is positioned within the header to remove solvent therefrom while avoiding interference with the main robotic arm. The solvent composition, temperature, pressure, viscosity, and purity are controlled to optimize the ultrasonic scrubbing action. The ultrasonic transducer is controlled at a power density, frequency, and on-off mode cycle such as to optimize scrubbing action within the range of transducer-to-surface distance and solvent layer thickness selected for the particular conditions encountered. Both solvent and transducer control actions are optimized by the programmable microprocessor. (author)

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

Ultrasonic testing device

International Nuclear Information System (INIS)

Lawrie, W.E.

1978-01-01

The ultrasonic transmitter made of polarized ferroelectric ceramic material (lead zirconate titanate) is arranged in a strip carrier which allows it to be introduced between the fuel elements of a fuel subassembly in a water cooled nuclear reactor. The ultrasonic transmitter is insulated relative to the carrier. The echo of the ra dal ultrasonic pulse is recorded which changes as faulty water filled fuel elements are detected. (RW) [de

Proliferation kinetics and survival of mammal cells after treatment with radiation of various ionization densities and with hyperthermia

International Nuclear Information System (INIS)

Schlag, H.

1977-01-01

Survival and proliferation kinetics of chinese hamster cells after Co-γ-, π - -meson irradiation, hyperthermia (40 - 43 0 C), and a combination of Co-γ irradiation and hyperthermia were studied in this paper. After γ-irradiation, exponential-phase and stationary-phase cells showed equal survival rates for equal doses. Cytofluorometric analysis showed that there was a dose-dependent delay in the synthesis phase with subsequent cell blocking in the G 2 +M phase. After irradiation with π - mesons, there is a dose-dependent accumulation in the G 2 +M phase, with a RBE of 2.2. The different response of S-phase cells to radiations of different LET may be explained with the inactivation kinetics typical of each type of radiation. The effectiveness of hyperthermal treatment depends on the stage of growth of the cells. A temperature of 40 0 C does not induce cell killing, not even after prolonged exposure. After 7 hours' exposure to 41 0 C, on the other hand, 80% of the cells are killed after blocking in G 2 +M. Exposure to 42 0 C for 1-2 h induces a synchronisation effect which is induced by a block in S and G 2 +M. After exposure to 42 0 C for 4 h, however, the cells blocked in S are killed in this phase. Combination of Co-γ radiation leads to increased cells killing and also to sensitization, especially of cells in the exponential growth stage. The proliferation kinetics effects of this combined treatment are the same as after pion irradiation. (orig.) [de

Modeling of ultrasonic processes utilizing a generic software framework

Science.gov (United States)

Bruns, P.; Twiefel, J.; Wallaschek, J.

2017-06-01

Modeling of ultrasonic processes is typically characterized by a high degree of complexity. Different domains and size scales must be regarded, so that it is rather difficult to build up a single detailed overall model. Developing partial models is a common approach to overcome this difficulty. In this paper a generic but simple software framework is presented which allows to coupe arbitrary partial models by slave modules with well-defined interfaces and a master module for coordination. Two examples are given to present the developed framework. The first one is the parameterization of a load model for ultrasonically-induced cavitation. The piezoelectric oscillator, its mounting, and the process load are described individually by partial models. These partial models then are coupled using the framework. The load model is composed of spring-damper-elements which are parameterized by experimental results. In the second example, the ideal mounting position for an oscillator utilized in ultrasonic assisted machining of stone is determined. Partial models for the ultrasonic oscillator, its mounting, the simplified contact process, and the workpiece’s material characteristics are presented. For both applications input and output variables are defined to meet the requirements of the framework’s interface.

The reliability of ultrasonic inspection and the critical defect size

International Nuclear Information System (INIS)

Vasilchenko, G.S.; Bely, V.E.; Ovchinnikov, A.V.; Rivkin, E.Yu.

1991-01-01

The ability to detect fabrication and service-induced defects in the welded joints of components and pipelines in nuclear power stations by ultrasonic inspection when this is conducted by using standard instruments and procedures appears to be insufficient. This fact was confirmed by the research carried out in PISC program and other studies. In order to increase the accuracy of measurement and to obtain the additional information on the character of any defect in ultrasonic testing as well as the validity of applying nondestructive testing data to strength calculation, scientific researches have been promoted and carried out in the USSR in a program under the guidance of NPO CNIITMASH. The reliability of the ultrasonic control of welded joints and the ways and means for its improvement are discussed. The presentation of the parameters realized by the ultrasonic inspection of defects in the form of schema for the use in strength calculation is explained. The calculation of stress intensity factor, the estimation of critical defect size, and the estimation of acceptable defect size are reported. (K.I.)

Hysteresis losses and specific absorption rate measurements in magnetic nanoparticles for hyperthermia applications.

Science.gov (United States)

Coïsson, Marco; Barrera, Gabriele; Celegato, Federica; Martino, Luca; Kane, Shashank N; Raghuvanshi, Saroj; Vinai, Franco; Tiberto, Paola

2017-06-01

Magnetic hysteresis loops areas and hyperthermia on magnetic nanoparticles have been studied with the aim of providing reliable and reproducible methods of measuring the specific absorption rate (SAR). The SAR of Fe 3 O 4 nanoparticles with two different mean sizes, and Ni 1-x Zn x Fe 2 O 4 ferrites with 0 ≤ x ≤ 0.8 has been measured with three approaches: static hysteresis loops areas, dynamic hysteresis loops areas and hyperthermia of a water solution. For dynamic loops and thermometric measurements, specific experimental setups have been developed, that operate at comparable frequencies (≈ 69kHz and ≈ 100kHz respectively) and rf magnetic field peak values (up to 100mT). The hyperthermia setup has been fully modelled to provide a direct measurement of the SAR of the magnetic nanoparticles by taking into account the heat exchange with the surrounding environment in non-adiabatic conditions and the parasitic heating of the water due to ionic currents. Dynamic hysteresis loops are shown to provide an accurate determination of the SAR except for superparamagnetic samples, where the boundary with a blocked regime could be crossed in dynamic conditions. Static hysteresis loops consistently underestimate the specific absorption rate but can be used to select the most promising samples. A means of reliably measure SAR of magnetic nanoparticles by different approaches for hyperthermia applications is presented and its validity discussed by comparing different methods. This work fits within the general subject of metrological traceability in medicine with a specific focus on magnetic hyperthermia. This article is part of a Special Issue entitled "Recent Advances in Bionanomaterials" Guest Editor: Dr. Marie-Louise Saboungi and Dr. Samuel D. Bader. Copyright © 2016 Elsevier B.V. All rights reserved.

Ultra-sonic observation in niobium hydride precipitation

International Nuclear Information System (INIS)

Florencio, O.; Pinatti, Dyonisio G.

1982-01-01

The hidrogen embrittlement of exothermic ocluders, had been considered as due to applied stress induced hydride precipitates leading to brittle fracture. The results of simultaneous measurements of macroscopic deformation and elastic change due to hydride precipitation, using the ultrasonic pulse-echo technique are showed. THen it was tested the possibility of kinectis precipitation parameters evoluation. (Author) [pt

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

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

Measurement of a 3D Ultrasonic Wavefield Using Pulsed Laser Holographic Microscopy for Ultrasonic Nondestructive Evaluation

Directory of Open Access Journals (Sweden)

Xing Wang

2018-02-01

Full Text Available In ultrasonic array imaging, 3D ultrasonic wavefields are normally recorded by an ultrasonic piezo array transducer. Its performance is limited by the configuration and size of the array transducer. In this paper, a method based on digital holographic interferometry is proposed to record the 3D ultrasonic wavefields instead of the array transducer, and the measurement system consisting of a pulsed laser, ultrasonic excitation, and synchronization and control circuit is designed. A consecutive sequence of holograms of ultrasonic wavefields are recorded by the system. The interferograms are calculated from the recorded holograms at different time sequence. The amplitudes and phases of the transient ultrasonic wavefields are recovered from the interferograms by phase unwrapping. The consecutive sequence of transient ultrasonic wavefields are stacked together to generate 3D ultrasonic wavefields. Simulation and experiments are carried out to verify the proposed technique, and preliminary results are presented.

pH- and NIR Light-Responsive Polymeric Prodrug Micelles for Hyperthermia-Assisted Site-Specific Chemotherapy to Reverse Drug Resistance in Cancer Treatment.

Science.gov (United States)

Li, Zuhong; Wang, Haibo; Chen, Yangjun; Wang, Yin; Li, Huan; Han, Haijie; Chen, Tingting; Jin, Qiao; Ji, Jian

2016-05-01

Despite the exciting advances in cancer chemotherapy over past decades, drug resistance in cancer treatment remains one of the primary reasons for therapeutic failure. IR-780 loaded pH-responsive polymeric prodrug micelles with near infrared (NIR) photothermal effect are developed to circumvent the drug resistance in cancer treatment. The polymeric prodrug micelles are stable in physiological environment, while exhibit fast doxorubicin (DOX) release in acidic condition and significant temperature elevation under NIR laser irradiation. Phosphorylcholine-based biomimetic micellar shell and acid-sensitive drug conjugation endow them with prolonged circulation time and reduced premature drug release during circulation to conduct tumor site-specific chemotherapy. The polymeric prodrug micelles combined with NIR laser irradiation could significantly enhance intracellular DOX accumulation and synergistically induce the cell apoptosis in DOX-resistant MCF-7/ADR cells. Meanwhile, the tumor site-specific chemotherapy combined with hyperthermia effect induces significant inhibition of MCF-7/ADR tumor growth in tumor-bearing mice. These results demonstrate that the well-designed IR-780 loaded polymeric prodrug micelles for hyperthermia-assisted site-specific chemotherapy present an effective approach to reverse drug resistance. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A new deconvolution method applied to ultrasonic images

International Nuclear Information System (INIS)

Sallard, J.

1999-01-01

This dissertation presents the development of a new method for restoration of ultrasonic signals. Our goal is to remove the perturbations induced by the ultrasonic probe and to help to characterize the defects due to a strong local discontinuity of the acoustic impedance. The point of view adopted consists in taking into account the physical properties in the signal processing to develop an algorithm which gives good results even on experimental data. The received ultrasonic signal is modeled as a convolution between a function that represents the waveform emitted by the transducer and a function that is abusively called the 'defect impulse response'. It is established that, in numerous cases, the ultrasonic signal can be expressed as a sum of weighted, phase-shifted replicas of a reference signal. Deconvolution is an ill-posed problem. A priori information must be taken into account to solve the problem. The a priori information translates the physical properties of the ultrasonic signals. The defect impulse response is modeled as a Double-Bernoulli-Gaussian sequence. Deconvolution becomes the problem of detection of the optimal Bernoulli sequence and estimation of the associated complex amplitudes. Optimal parameters of the sequence are those which maximize a likelihood function. We develop a new estimation procedure based on an optimization process. An adapted initialization procedure and an iterative algorithm enables to quickly process a huge number of data. Many experimental ultrasonic data that reflect usual control configurations have been processed and the results demonstrate the robustness of the method. Our algorithm enables not only to remove the waveform emitted by the transducer but also to estimate the phase. This parameter is useful for defect characterization. At last the algorithm makes easier data interpretation by concentrating information. So automatic characterization should be possible in the future. (author)

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-targeted thermosensitive liposomes (TSL) and CTSL were developed, loaded with Dox and characterized. Blood kinetics and biodistribution of Dox-TSL and Dox-CTSL were followed in B16BL6 tumor bearing mice upon normothermia (NT) or initial hyperthermia conditions. Efficacy study in B...

[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.

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

Local hyperthermia and artificial hyperglycemia in combined treatment of patients with rectum cancer

International Nuclear Information System (INIS)

Bezmen, V.A.; Illarionov, A.A.; Novokhrost, V.I.; Shilov, N.I.; Ospishchev, A.A.; Kejs, G.D.

1990-01-01

To study prospects of application of local hyperthermia, artificial hyperglycemia and radiotherapy in a preoperative period, 31 patients with rectum cancer were studied. The treatment included 3-hour artificial hyperglycemia first, then local SHF hyperthermia and telegamma irradiation using large-fractioned doses (ROD is 5 Gy, COD is 20 Gy). No serious side-effects were observed during the preoperative treatment period. The immediate and early results of combined treatment promise to improve the effectiveness of treatment of patients with rectum cancer. 3 refs

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)

Ultrasonic unit for line-by-line ultrasonic scanning of bodies

International Nuclear Information System (INIS)

Soldner, R.

1978-01-01

The ultrasonic unit for medical diagnostics operates by the sectorial scanning principle, which avoids direct coupling of the transducer head to the surface of the body. For this purpose, several transmitter/receiver units (approx. 100) are arranged on a partial ring of a circular arc and the ultrasonic beams, which can be triggered sequentially in time, are directed at a common intersection behind the ultrasonic window of the unit, i.e., outside the unit. A mechanical system is employed to set and adjust the partial ring carrying the transmitter/receiver units. (DG) [de

Physiologic and Perceptual Responses to Cold-Shower Cooling After Exercise-Induced Hyperthermia.

Science.gov (United States)

Butts, Cory L; McDermott, Brendon P; Buening, Brian J; Bonacci, Jeffrey A; Ganio, Matthew S; Adams, J D; Tucker, Matthew A; Kavouras, Stavros A

2016-03-01

Exercise conducted in hot, humid environments increases the risk for exertional heat stroke (EHS). The current recommended treatment of EHS is cold-water immersion; however, limitations may require the use of alternative resources such as a cold shower (CS) or dousing with a hose to cool EHS patients. To investigate the cooling effectiveness of a CS after exercise-induced hyperthermia. Randomized, crossover controlled study. Environmental chamber (temperature = 33.4°C ± 2.1°C; relative humidity = 27.1% ± 1.4%). Seventeen participants (10 male, 7 female; height = 1.75 ± 0.07 m, body mass = 70.4 ± 8.7 kg, body surface area = 1.85 ± 0.13 m(2), age range = 19-35 years) volunteered. On 2 occasions, participants completed matched-intensity volitional exercise on an ergometer or treadmill to elevate rectal temperature to ≥39°C or until participant fatigue prevented continuation (reaching at least 38.5°C). They were then either treated with a CS (20.8°C ± 0.80°C) or seated in the chamber (control [CON] condition) for 15 minutes. Rectal temperature, calculated cooling rate, heart rate, and perceptual measures (thermal sensation and perceived muscle pain). The rectal temperature (P = .98), heart rate (P = .85), thermal sensation (P = .69), and muscle pain (P = .31) were not different during exercise for the CS and CON trials (P > .05). Overall, the cooling rate was faster during CS (0.07°C/min ± 0.03°C/min) than during CON (0.04°C/min ± 0.03°C/min; t16 = 2.77, P = .01). Heart-rate changes were greater during CS (45 ± 20 beats per minute) compared with CON (27 ± 10 beats per minute; t16 = 3.32, P = .004). Thermal sensation was reduced to a greater extent with CS than with CON (F3,45 = 41.12, P < .001). Although the CS facilitated cooling rates faster than no treatment, clinicians should continue to advocate for accepted cooling modalities and use CS only if no other validated means of cooling are available.

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

Non-Invasive Radiofrequency Field Treatment to Produce Hepatic Hyperthermia: Efficacy and Safety in Swine

OpenAIRE

,; ,; ,; ,; ,; ,; ,; ,; ,

2017-01-01

The Kanzius non-invasive radio-frequency hyperthermia system (KNiRFH) has been investigated as a treatment option for hepatic hyperthermia cancer therapy. The treatment involves exposing the patient to an external high-power RF (13.56 MHz) electric field, whereby the propagating waves penetrate deep into the tumor causing targeted heating based on differential tissue dielectric properties. However, a comprehensive examination of the Kanzius system alongside any associated toxicities and its a...

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).

Evaluation of Effect by Internal Flow on Ultrasonic Testing Flaw Sizing in Piping

International Nuclear Information System (INIS)

Lee, Jeong Seok; Yoon, Byung Sik; Kim, Yong Sik

2013-01-01

In this study, the ultrasonic amplitude difference between air filled and water filled piping in nuclear power plant is compared by modeling approach. In this study, ultrasonic amplitude differences between air and water filled pipe are evaluated by modeling approach. Consequently, we propose the following results. The ultrasonic amplitude difference between air and water filled condition is measured by lower than 1 dB in modeling calculation. The flaw length sizing error between air and water filled condition shows same results based on 12 dB drop method even thought the amplitude difference is 1 dB. Most of the piping welds in nuclear power plants are inspected periodically using ultrasonic techniques to detect service-induced flaws such as IGSCC cracking. The inspection results provide information such as location, maximum amplitude response, ultrasonic length, height and finally the nature or flaw pattern. The founded flaw in ultrasonic inspection is accepted or rejected based on these information. Specially, the amplitude of flaw response is very important to estimate the flaw size. Currently the ultrasonic inspections in nuclear power plant components are performed by specific inspection procedure which describing inspection technique include inspection system, calibration methodology and flaw characterizing methodology. To perform ultrasonic inspection during in-service inspection, reference gain should be established before starting ultrasonic inspection by requirement of ASME code. This reference gain used as basic criteria to evaluate flaw sizing. Sometimes, a little difference in establishing reference gain between calibration and field condition can lead to deviation in flaw sizing. Due to this difference, the inspection result may cause flaw sizing error

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

[Detection of peranesthetic malignant hyperthermia by muscle contracture tests and NMR spectroscopy].

Science.gov (United States)

Kozak-Reiss, G; Gascard, J P; Redouane-Bénichou, K

1986-01-01

To diagnose malignant hyperthermia susceptibility (MHS), caffeine and halothane contracture tests were performed on six patients. One of them, who presented a peroperative crisis, was recognized as MHS; the five others were negative (MHN). By means of 31P-NMR spectroscopy, the muscular energetic metabolism of these patients was studied during and after moderate exercise in normal and moderate ischaemic conditions. Metabolic abnormalities appeared in the MHS patient. It must be concluded therefore that malignant hyperthermia is a latent myopathy. 31P-NMR spectroscopy appeared to be a useful non-invasive tool for screening for this affliction.

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

Nano-magnetite coated with gold: alternative oncological therapy with magnetic hyperthermia; Nanomagnetita recubierta de oro: terapia oncologica alternativa con hipertermia magnetica

Energy Technology Data Exchange (ETDEWEB)

Cordova F, T.; Jimenez G, O.; Basurto I, G. [Universidad de Guanajuato, Campus Leon, Division de Ciencias e Ingenierias, Loma del Bosque 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Martinez E, J. C., E-mail: theo@fisica.ugto.mx [IPN, Unidad Profesional Interdisciplinaria de Ingenieria Campus Guanajuato, Av. Mineral de Valenciana 200, Industrial Puerto Interior, 36275 Silao de la Victoria, Guanajuato (Mexico)

2017-10-15

Localized hyperthermia performed through the use of nanoparticles is one of the most promising procedures for the cancer treatment. In this work, the synthesis of magnetite nanoparticles (Fe{sub 2}O{sub 3}) was carried out using the thermal decomposition method. Subsequently, these nanoparticles were coated with gold and suspended in aqueous phase. As a result, nanoparticles capable of being heated by the application of an alternating magnetic field or through the use of infrared radiation were obtained. As an additional feature, these nanoparticles are biocompatible thanks to their golden coating. The synthesized nanoparticles can be functionalized by the conjugation of a molecule (aptamer, antibody, peptide, etc.) whose target is a cancer cell in order to adhere to it the nanoparticle-marker complex, to subsequently carry out a heating with the objective of induce cell death. In conclusion, the synthesized nanoparticles allow providing an alternative treatment for cancer through the use of localized hyperthermia, either using magnetic or infrared heating. (Author)

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

Modifications of animal response to Partial Body Hyperthermia (PBH) as a potent radioprotector: Relationships with animal age and sex

International Nuclear Information System (INIS)

Alya, G.

2002-04-01

Currently available radio protectors are poorly tolerated in man. Thus, the use of the most promising agent, WR 2721 [S-2 (3-aminoprophylamino) ethylphosphoro thioic acid] has been limited due to its poor clinical tolerance. In a search for less toxic and/or without side effects agents, radioprotective effects of partial body hyperthermia (PBH) have been tested on Wistar rats of both sexes at different ages. Groups of male and female rats were irradiated [Total Body Irradiation (TBI)] in a perforated plexi-glass boxes using a 60 Co source. The irradiation dose was 9 Gy which is considered as a lethal dose of 100% of animals (LD 1 00) (the dose rate was = 80-85 rad.min -1 ). Irradiated animals were monitored for 2 weeks at least, and percentage of survival was calculated on the control groups. Partial Body Hyperthermia was carried out 20 hours prior to irradiation of 200-250 gr rats (by immersion of lower parts and legs of rats, in water bath at 43 centigrade for 1 h). Irradiated PBH treated animals were monitored for 30 days after irradiation and the survival percentage was calculated. Our results showed that PBH treatment, can be considered as a radioprotector. Moreover, the results of the undertaken study showed that this response changes as a function of animal age and sex. Thus, PBH was more effective on young rats (males and females), However, after 30 days of irradiation, PBH was more effective on males than females. The conclusion reached by this study is that animal response to PBH decreases with aging. Despite that the precise mechanism by which PBH induces retardation of death and enhance survival of rats is still obscure, Hyperthermia is known to enhance the immune response. Literature reveals that the productions of cytokines such as interferons and interleukins as well as natural killer cell activity are enhanced after hyperthermia. (author)

The effect of magnetic nanoparticles on the acoustic properties of tissue-mimicking agar-gel phantoms

Energy Technology Data Exchange (ETDEWEB)

Józefczak, A., E-mail: aras@amu.edu.pl [Institute of Acoustics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Kaczmarek, K. [Institute of Acoustics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Kubovčíková, M. [Institute of Experimental Physics, Slovak Academy of Sciences, Košice (Slovakia); Rozynek, Z.; Hornowski, T. [Institute of Acoustics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland)

2017-06-01

In ultrasonic hyperthermia, ultrasound-induced heating is achieved by the absorption of wave energy and its conversion into heat. The effectiveness of ultrasounds can be improved by using sonosensitisers that greatly attenuate ultrasonic waves and then dissipate the acquired energy in the form of heat. One possible candidate for such a sonosensitiser are superparamagnetic iron oxide nanoparticles. Here, we used magnetic nanoparticles embedded in a tissue-mimicking agar-gel matrix. Such tissue-mimicking phantoms possess acoustic properties similar to those of real tissues, and are used as a tool for performance testing and optimisation of medical ultrasound systems. In this work, we studied the effect of magnetic nanoparticles on the acoustic properties of agar-gel phantoms, including the attenuation of ultrasonic waves. - Highlights: • Ultrasonic insertion technique is used to study acoustic properties of agar-gel phantoms with and without magnetic particles. • The addition of magnetic nanoparticles improves effectiveness of ultrasound heating in agar phantoms. • Acoustics properties of a pure agar-gel phantom are altered by adding nanoparticles.

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

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.

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

Evaluation on damage of pipe using ultrasonic and acoustic emission

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin Kyung; Lee, Sang Pill; Lee, Moon Hee [Dongeui Univ., Busan (Korea, Republic of); Lee, Joon Hyun [Pusan National Univ., Busan (Korea, Republic of)

2008-07-01

An elastic waves like ultrasonic and acoustic emission were used to evaluate the propagating properties of the wave in pipe, and study on mode conversion of the elastic wave due to the defects on the pipe was performed. In this study an Acoustic Emission (AE) sensor was used to receive the propagated ultrasonic wave. AE technique has a advantage that it can identify the received ultrasonic wave by the analysis of the AE parameters such as count, energy, frequency, duration time and amplitude. For transmitting and receiving of the wave, an universal angle wedge was manufactured. The optimum angles for transmitting of ultrasonic wave and signal receiving at the attached AE sensor on the pipe were determined. Theoretical dispersion curve was compared with the results of the time-frequency analysis based on the wavelet transformation. The received modes showed a good agreement with theoretical one. The used ultrasonic sensor was 1MHz, and AE sensor was broadband. The artificial cracks were induced in the pipe to measure the propagation characteristics of the elastic wave for the cracks. AE parameters for the received signals were also varied with the crack types in the pipe. AE parameters of amplitude and duration time were more effective factors than the analysis of mode conversion for evaluation of the cracks in the pipe.

Influences of ultrasonic irradiation on the morphology and structure of nanoporous Co nanoparticles during chemical dealloying

Directory of Open Access Journals (Sweden)

Hui Li

2016-12-01

Full Text Available The Co-61.8 wt% Al nanoparticles of 45 nm were prepared by hydrogen plasma-metal reaction (HPMR method. The nanoparticles display core shell structure with Al13Co4 and CoAl core and aluminum oxide shell (about 2 nm. Under ultrasonic irradiation, nanoporous fcc-Co nanoparticles were produced successfully by chemically dealloying the Co-Al nanoparticles at room temperature, whereas, without ultrasonic irradiation CoAl phase could hardly react with sodium hydroxide solution. At 323 K the Co-Al nanoparticles could be dealloyed to fcc-Co and hcp-Co phases even without ultrasonic irradiation. The surface area of the dealloyed nanoparticles under ultrasonic irradiation was larger than that of the dealloyed sample without ultrasonic irradiation at the same temperature. It is believed that the microjet and shock-wave induced by ultrasonic irradiation give rise to particles size reduction, interparticle collision and surface cleaning, and accelerate the dealloying process and the phase transformation.

Hyperthermia in low aspect-ratio magnetic nanotubes for biomedical applications

Science.gov (United States)

Gutierrez-Guzman, D. F.; Lizardi, L. I.; Otálora, J. A.; Landeros, P.

2017-03-01

A simple model for the magnetization reversal process of low aspect-ratio ferromagnetic nanotubes (MNTs) is presented. Because of advantages over other geometries, these structures are interesting for biomedical applications, such as magnetic hyperthermia cancer therapy, where the heat released during magnetic reversal is used to destroy tumors. For example, the tubular geometry provides two independent functional surfaces that may be selectively manipulated and also gives a storage cavity. Owing to their large surface to weight ratio and low mass density, MNTs are not decanted by gravity. We calculated magnetic phase diagrams, energy barriers, nucleation fields, and the amount of dissipated heat and specific absorption rate for magnetite nanotubes. The geometrical parameters were varied, and simple formulae were used to optimize the tube response under alternating excitation, as required for magnetic hyperthermia applications.

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)

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.

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

Artificial Intelligence Assists Ultrasonic Inspection

Science.gov (United States)

Schaefer, Lloyd A.; Willenberg, James D.

1992-01-01

Subtle indications of flaws extracted from ultrasonic waveforms. Ultrasonic-inspection system uses artificial intelligence to help in identification of hidden flaws in electron-beam-welded castings. System involves application of flaw-classification logic to analysis of ultrasonic waveforms.

Pharmacological evaluation of SN79, a sigma (σ) receptor ligand, against methamphetamine-induced neurotoxicity in vivo.

Science.gov (United States)

Kaushal, Nidhi; Seminerio, Michael J; Robson, Matthew J; McCurdy, Christopher R; Matsumoto, Rae R

2013-08-01

Methamphetamine is a highly addictive psychostimulant drug of abuse, causing hyperthermia and neurotoxicity at high doses. Currently, there is no clinically proven pharmacotherapy to treat these effects of methamphetamine, necessitating identification of potential novel therapeutic targets. Earlier studies showed that methamphetamine binds to sigma (σ) receptors in the brain at physiologically relevant concentrations, where it "acts in part as an agonist." SN79 (6-acetyl-3-(4-(4-(4-florophenyl)piperazin-1-yl)butyl)benzo[d]oxazol-2(3H)-one) was synthesized as a putative σ receptor antagonist with nanomolar affinity and selectivity for σ receptors over 57 other binding sites. SN79 pretreatment afforded protection against methamphetamine-induced hyperthermia and striatal dopaminergic and serotonergic neurotoxicity in male, Swiss Webster mice (measured as depletions in striatal dopamine and serotonin levels, and reductions in striatal dopamine and serotonin transporter expression levels). In contrast, di-o-tolylguanidine (DTG), a well established σ receptor agonist, increased the lethal effects of methamphetamine, although it did not further exacerbate methamphetamine-induced hyperthermia. Together, the data implicate σ receptors in the direct modulation of some effects of methamphetamine such as lethality, while having a modulatory role which can mitigate other methamphetamine-induced effects such as hyperthermia and neurotoxicity. Copyright © 2012 Elsevier B.V. and ECNP. All rights reserved.

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

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.

Ultrasonic grinding method

International Nuclear Information System (INIS)

Miyahara, Shuji.

1990-01-01

An ultrasonic generator and a liquid supply nozzle are opposed to an object to be ground and a pump is started in this state to supply an organic solvent. Matters to be decontaminated which adheres to the surface of the object to be ground and are difficult to be removed by a mere mechanical removing method can be eliminated previously by the surface active effect of the organic solvent such as ethanol prior to the oscillation of the ultrasonic generator. Subsequently, when the ultrasonic generator is oscillated, scales in the floated state can be removed simply. Further, since the organic solvent can penetrate to provide the surface active effect even in such a narrow portion that the top end of the ultrasonic generator is difficult to the intruded at the surface of the object to be ground, the decontaminating treatment can be applied also to such a narrow portion. (T.M.)

Effects of ultrasonic irradiation on crystallization and structural properties of EMT-type zeolite nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Ng, Eng-Poh, E-mail: epng@usm.my [School of Chemical Sciences, Universiti Sains Malaysia, USM, 11800 Penang (Malaysia); Awala, Hussein [Laboratoire Catalyse & Spectrochimie, CNRS-ENSICAEN, Université de Caen (France); Ghoy, Jia-Pei [School of Chemical Sciences, Universiti Sains Malaysia, USM, 11800 Penang (Malaysia); Vicente, Aurélie [Laboratoire Catalyse & Spectrochimie, CNRS-ENSICAEN, Université de Caen (France); Ling, Tau Chuan [Institute of Biological Sciences, Faculty of Science, University of Malaya (Malaysia); Ng, Yun Hau [School of Chemical Engineering, The University of New South Wales, Sydney (Australia); Mintova, Svetlana [Laboratoire Catalyse & Spectrochimie, CNRS-ENSICAEN, Université de Caen (France); Adam, Farook, E-mail: farook@usm.my [School of Chemical Sciences, Universiti Sains Malaysia, USM, 11800 Penang (Malaysia)

2015-06-01

Synthesis of EMT zeolite nanocrystals from rice husk ash biomass (RHA) under continuous ultrasonic irradiation is reported. The aging, nucleation and crystallization stages of EMT zeolite in the system were monitored at ambient temperature, and compared with the conventional hydrothermal method. It was found that ultrasonic wave induced rapid crystal growth of the nanosized EMT zeolite. Complete crystallization of EMT nanocrystals was achieved within 24 h which was much faster than conventional hydrothermal synthesis (36 h). Furthermore, XRD and TEM analyses revealed that more nuclei were formed during the nucleation stage, allowing the preparation of smaller zeolite nanocrystals with high crystallinity. The results also showed that sonocrystallization produced EMT zeolite with high yield (ca. 80%). The ultrasound-prepared EMT nanocrystals were also found to have high porosity and high hydrophilicity, making the material promising for water sorption applications including vapor sensing, heat pump and adsorption technologies. - Highlights: • Nanosized EMT zeolites are formed from rice husk ash under ultrasonic irradiation. • The effects of ultrasonic waves in nanosized EMT zeolite synthesis are studied. • Ultrasound induces rapid crystal growth and produces high zeolite yield. • Smaller zeolite nanocrystals with high crystallinity and large defect sites are obtained. • Improved surface hydrophilicity of crystals is beneficial for water sorption applications.

ULTRASONIC ASSEMBLY [REVIEW

Directory of Open Access Journals (Sweden)

PORAV Viorica

2015-05-01

Full Text Available The paper exposes the possibility of machine producesers to optimize the costs of clothes assembling. Ultrasonic systems being frequently utilized have many advantages on semi products of synthetic textile and technical textile. First of all, sewing – cutting process can be accomplished under high speeds and rate of losses can be minimized. Cutting seal applications are frequently used for underwear and sportswear. Slicing and unit cutting machines, as well as portable sealing machines are available for labeling sector. Products such as bag, pocket and cover can be sewed in a seamless manner for promotion purposes. All objects in terms of accessories are obtained in same standard. Our quilting machines are preferred in worldwide due to its threadless, high quality sealing. An alternative to the classic sewing assembly, with thread and needles is ultrasonic seaming. In ultrasonic welding, there are no connective bolts, nails, soldering materials, or adhesives necessary to bind the materials together. Ultrasonic is defined as acoustic frequencies above the range audible to the human ear. Ultrasonic frequencies are administered to the fabric from the sonotrode of bonding machine. The high frequency and powerful energy produced, when is release in one special environment, the ultrasound heating this environment. The ability to ultrasonic weld textiles and films depend on their thermoplastic contents and the desired end results. The paper defines the weld ability of more common textiles and films. The welding refers to all types of bonding and sealing, as in point bonding of fabric, or continuous sealing of film.

A randomized clinical trial of hyperthermia and radiation versus radiation alone for superficially located cancers

International Nuclear Information System (INIS)

Egawa, Sunao; Tsukiyama, Iwao; Watanabe, Shaw

1989-01-01

A randomized clinical trial was performed in order to evaluate the effect of combined hyperthermia and radiation for superficially located tumors. Ten institutions participated in this study and 92 evaluable patients were entered from September 1985 to March 1987 (44 patients for radiation plus hyperthermia and 48 for radiation only). Superficially located tumors, more than 3x3 cm in diameter, regardless of whether they were primary or metastatic, and of their histology, were included in the study. Radiotherapy was performed by the conventional fractionation method (2 Gyx5/week). Hyperthermia was conducted once a week. There was no statistical difference between the two groups regarding age, sex, the distribution of tumors and treatment parameters. The complete response (CR) and partial response (PR) rate for the hyperthermia plus radiation group was 81.8%, while the rate for the radiation alone group was 62.6% (p<0.05). Six factors were selected for analysis of the above effect by a multiple logistic model. Sex contributed the most (p=0.001), then the site of the tumor (p=0.016) and the method of treatment (p=0.023). Sex and the site influenced the results. Age, irradiation dose and frequency and duration of heating were not significant factors for response to treatment. (author)

Iron oxide nanoparticles stabilized with a bilayer of oleic acid for magnetic hyperthermia and MRI applications

Energy Technology Data Exchange (ETDEWEB)

Soares, Paula I.P. [i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516 Caparica (Portugal); Laia, César A.T. [Laboratório Associado para a Química Verde (LAQV), REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Carvalho, Alexandra [i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516 Caparica (Portugal); Pereira, Laura C.J.; Coutinho, Joana T. [C2TN, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, ao km 139,7, 2695-066 Bobadela LRS (Portugal); Ferreira, Isabel M.M., E-mail: imf@fct.unl.pt [i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516 Caparica (Portugal); Novo, Carlos M.M. [Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, IHMT/UNL, 1349-008 Lisboa (Portugal); Borges, João Paulo, E-mail: jpb@fct.unl.pt [i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516 Caparica (Portugal)

2016-10-15

Highlights: • Superparamagnetic iron oxide nanoparticles were stabilized with oleic acid. • Maximum stabilization was achieved at neutral pH. • Magnetic resonance imaging and magnetic hyperthermia applications were tested. • The produced nanoparticles are viable for both biomedical applications. - Abstract: Iron oxide nanoparticles (Fe{sub 3}O{sub 4}, IONPs) are promising candidates for several biomedical applications such as magnetic hyperthermia and as contrast agents for magnetic resonance imaging (MRI). However, their colloidal stability in physiological conditions hinders their application requiring the use of biocompatible surfactant agents. The present investigation focuses on obtaining highly stable IONPs, stabilized by the presence of an oleic acid bilayer. Critical aspects such as oleic acid concentration and pH were optimized to ensure maximum stability. NPs composed of an iron oxide core with an average diameter of 9 nm measured using transmission electron microscopy (TEM) form agglomerates with an hydrodynamic diameter of around 170 nm when dispersed in water in the presence of an oleic acid bilayer, remaining stable (zeta potential of −120 mV). Magnetic hyperthermia and the relaxivities measurements show high efficiency at neutral pH which enables their use for both magnetic hyperthermia and MRI.

Iron oxide nanoparticles stabilized with a bilayer of oleic acid for magnetic hyperthermia and MRI applications

International Nuclear Information System (INIS)

Soares, Paula I.P.; Laia, César A.T.; Carvalho, Alexandra; Pereira, Laura C.J.; Coutinho, Joana T.; Ferreira, Isabel M.M.; Novo, Carlos M.M.; Borges, João Paulo

2016-01-01

Highlights: • Superparamagnetic iron oxide nanoparticles were stabilized with oleic acid. • Maximum stabilization was achieved at neutral pH. • Magnetic resonance imaging and magnetic hyperthermia applications were tested. • The produced nanoparticles are viable for both biomedical applications. - Abstract: Iron oxide nanoparticles (Fe_3O_4, IONPs) are promising candidates for several biomedical applications such as magnetic hyperthermia and as contrast agents for magnetic resonance imaging (MRI). However, their colloidal stability in physiological conditions hinders their application requiring the use of biocompatible surfactant agents. The present investigation focuses on obtaining highly stable IONPs, stabilized by the presence of an oleic acid bilayer. Critical aspects such as oleic acid concentration and pH were optimized to ensure maximum stability. NPs composed of an iron oxide core with an average diameter of 9 nm measured using transmission electron microscopy (TEM) form agglomerates with an hydrodynamic diameter of around 170 nm when dispersed in water in the presence of an oleic acid bilayer, remaining stable (zeta potential of −120 mV). Magnetic hyperthermia and the relaxivities measurements show high efficiency at neutral pH which enables their use for both magnetic hyperthermia and MRI.

Effects of intraoperative irradiation (IORT) and intraoperative hyperthermia (IOHT) on canine sciatic nerve: histopathological and morphometric studies

International Nuclear Information System (INIS)

Vujaskovic, Zeljko; Powers, Barbara E.; Paardekoper, Gabriel; Gillette, Sharon M.; Gillette, Edward L.; Colacchio, Thomas A.

1999-01-01

Purpose/Objective: Peripheral neuropathies have emerged as the major dose-limiting complication reported after intraoperative radiation therapy (IORT). The combination of IORT with hyperthermia may further increase the risk of peripheral nerve injury. The objective of this study was to evaluate histopathological and histomorphometric changes in the sciatic nerve of dogs, after IORT with or without hyperthermia treatment. Methods and Materials: Young adult beagle dogs were randomized into five groups of 3-5 dogs each to receive IORT doses of 16, 20, 24, 28, or 32 Gy. Six groups of 4-5 dogs each received IORT doses of 12, 16, 20, 24, or 28 Gy simultaneously with 44 deg. C of intraoperative hyperthermia (IOHT) for 60 min. One group of dogs acted as hyperthermia-alone controls. Two years after the treatment, dogs were euthanized, and histopathological and morphometric analyses were performed. Results: Qualitative histological analysis showed prominant changes such as focal necrosis, mineralization, fibrosis, and severe fiber loss in dogs which received combined treatment. Histomorphometric results showed a significantly higher decrease in axon and myelin and small blood vessels, with a corresponding increase in connective tissue in dogs receiving IORT plus hyperthermia treatment. The effective dose for 50% of nerve fiber loss (ED 50 ) in dogs exposed to IORT only was 25.3 Gy. The ED 50 for nerve fiber loss in dogs exposed to IORT combined with IOHT was 14.8 Gy. The thermal enhancement ratio (TER) was 1.7. Conclusion: The probability of developing peripheral neuropathies in a large animal model is higher when IORT is combined with IOHT, when compared to IORT application alone. To minimize the risk of peripheral neuropathy, clinical treatment protocols for the combination of IORT and hyperthermia should not assume a thermal enhancement ratio (TER) to be lower than 1.5

Ultrasonic determination of thermodynamic threshold parameters for irreversible cutaneous burns

Science.gov (United States)

Cantrell, J. H., Jr.

1982-01-01

In vivo ultrasonic measurements of the depth of conductive cutaneous burns experimentally induced in anesthetized Yorkshire pigs are reported as a function of burn time for the case in which the skin surface temperature is maintained at 100 C. The data are used in the solution of the one-dimensional heat diffusion equation with time-dependent boundary conditions to obtain the threshold temperature and the energy of transformation per unit mass associated with the transition of the tissue from the state of viability to the state of necrosis. The simplicity of the mathematical model and the expediency of the ultrasonic measurements in studies of thermal injury are emphasized.

A comparison of sputum induction methods: ultrasonic vs compressed-air nebulizer and hypertonic vs isotonic saline inhalation.

Science.gov (United States)

Loh, L C; Eg, K P; Puspanathan, P; Tang, S P; Yip, K S; Vijayasingham, P; Thayaparan, T; Kumar, S

2004-03-01

Airway inflammation can be demonstrated by the modem method of sputum induction using ultrasonic nebulizer and hypertonic saline. We studied whether compressed-air nebulizer and isotonic saline which are commonly available and cost less, are as effective in inducing sputum in normal adult subjects as the above mentioned tools. Sixteen subjects underwent weekly sputum induction in the following manner: ultrasonic nebulizer (Medix Sonix 2000, Clement Clarke, UK) using hypertonic saline, ultrasonic nebulizer using isotonic saline, compressed-air nebulizer (BestNeb, Taiwan) using hypertonic saline, and compressed-air nebulizer using isotonic saline. Overall, the use of an ultrasonic nebulizer and hypertonic saline yielded significantly higher total sputum cell counts and a higher percentage of cell viability than compressed-air nebulizers and isotonic saline. With the latter, there was a trend towards squamous cell contaminations. The proportion of various sputum cell types was not significantly different between the groups, and the reproducibility in sputum macrophages and neutrophils was high (Intraclass correlation coefficient, r [95%CI]: 0.65 [0.30-0.91] and 0.58 [0.22-0.89], p compressed-air nebulizers and isotonic saline. We conclude that in normal subjects, although both nebulizers and saline types can induce sputum with reproducible cellular profile, ultrasonic nebulizers and hypertonic saline are more effective but less well tolerated.

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 ...

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.

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.

The effect of hypofractionated radiation and magnetic nanoparticle hyperthermia on tumor immunogenicity and overall treatment response

Science.gov (United States)

Hoopes, P. Jack; Wagner, Robert J.; Song, Ailin; Osterberg, Bjorn; Gladstone, David J.; Bursey, Alicea A.; Fiering, Steven N.; Giustini, Andrew J.

2017-02-01

It is now known that many tumors develop molecular signals (immune checkpoint modulators) that inhibit an effective tumor immune response. New information also suggest that even well-known cancer treatment modalities such as radiation and hyperthermia generate potentially beneficial immune responses that have been blocked or mitigated by such immune checkpoints, or similar molecules. The cancer therapy challenge is to; a) identify these treatment-based immune signals (proteins, antigens, etc.); b) the treatment doses or regimens that produce them; and c) the mechanisms that block or have the potential to promote them. The goal of this preliminary study, using the B6 mouse - B16 tumor model, clinically relevant radiation doses and fractionation schemes (including those used clinically in hypofractionated radiation therapy), magnetic nanoparticle hyperthermia (mNPH) and sophisticated protein, immune and tumor growth analysis techniques and modulators, is to determine the effect of specific radiation or hyperthermia alone and combined on overall treatment efficacy and immunologic response mechanisms. Preliminary analysis suggests that radiation dose (10 Gy vs. 2 Gy) significantly alters the mechanism of cell death (apoptosis vs. mitosis vs. necrosis) and the resulting immunogenicity. Our hypothesis and data suggest this difference is protein/antigen and immune recognition-based. Similarly, our evidence suggest that radiation doses larger than the conventional 2 Gy dose and specific hyperthermia doses and techniques (including mNP hyperthermia treatment) can be immunologically different, and potentially superior to, the radiation and heat therapy regimens that are typically used in research and clinical practice.

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

Nonlinear ultrasonic wave modulation for online fatigue crack detection

Science.gov (United States)

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

2014-02-01

This study presents a fatigue crack detection technique using nonlinear ultrasonic wave modulation. Ultrasonic waves at two distinctive driving frequencies are generated and corresponding ultrasonic responses are measured using permanently installed lead zirconate titanate (PZT) transducers with a potential for continuous monitoring. Here, the input signal at the lower driving frequency is often referred to as a 'pumping' signal, and the higher frequency input is referred to as a 'probing' signal. The presence of a system nonlinearity, such as a crack formation, can provide a mechanism for nonlinear wave modulation, and create spectral sidebands around the frequency of the probing signal. A signal processing technique combining linear response subtraction (LRS) and synchronous demodulation (SD) is developed specifically to extract the crack-induced spectral sidebands. The proposed crack detection method is successfully applied to identify actual fatigue cracks grown in metallic plate and complex fitting-lug specimens. Finally, the effect of pumping and probing frequencies on the amplitude of the first spectral sideband is investigated using the first sideband spectrogram (FSS) obtained by sweeping both pumping and probing signals over specified frequency ranges.

Water dispersible superparamagnetic Cobalt iron oxide nanoparticles for magnetic fluid hyperthermia

Energy Technology Data Exchange (ETDEWEB)

Salunkhe, Ashwini B. [Centre for advanced materials research, Department of Physics, Savitribai Phule Pune University, Pune 411007 (India); Soft matter and molecular biophysics group, Department of Applied Physics, University of Santiago de Compostela, Santiago de Compostela (Spain); Khot, Vishwajeet M. [Department of Physics and Astronomy, University College London (United Kingdom); Ruso, Juan M. [Soft matter and molecular biophysics group, Department of Applied Physics, University of Santiago de Compostela, Santiago de Compostela (Spain); Patil, S.I., E-mail: patil@physics.unipune.ac.in [Centre for advanced materials research, Department of Physics, Savitribai Phule Pune University, Pune 411007 (India)

2016-12-01

Superparamagnetic nanoparticles of Cobalt iron oxide (CoFe{sub 2}O{sub 4}) are synthesized chemically, and dispersed in an aqueous suspension for hyperthermia therapy application. Different parameters such as magnetic field intensity, particle concentration which regulates the competence of CoFe{sub 2}O{sub 4} nanoparticle as a heating agents in hyperthermia are investigated. Specific absorption rate (SAR) decreases with increase in the particle concentration and increases with increase in applied magnetic field intensity. Highest value of SAR is found to be 91.84 W g{sup −1} for 5 mg. mL{sup −1} concentration. Oleic acid conjugated polyethylene glycol (OA-PEG) coated CoFe{sub 2}O{sub 4} nanoparticles have shown superior cyto-compatibility over uncoated nanoparticles to L929 mice fibroblast cell lines for concentrations below 2 mg. mL{sup −1}. Present work provides the underpinning for the use of CoFe{sub 2}O{sub 4} nanoparticles as a potential heating mediator for magnetic fluid hyperthermia. - Highlights: • Superparamagnetic, water dispersible CoFe{sub 2}O{sub 4} NPs were synthesized by simple and cost effective Co precipitation route. • Effect of coating on various physical and chemical properties of CoFe{sub 2}O{sub 4} NPs were studied. • The effect of coating on induction heating as well as biocompatibility of NPs were studied.

Remote consulting based on ultrasonic digital immages and dynamic ultrasonic sequences

Science.gov (United States)

Margan, Anamarija; Rustemović, Nadan

2006-03-01

Telematic ultrasonic diagnostics is a relatively new tool in providing health care to patients in remote, islolated communities. Our project facility, "The Virtual Polyclinic - A Specialists' Consulting Network for the Islands", is located on the island of Cres in the Adriatic Sea in Croatia and has been extending telemedical services to the archipelago population since 2000. Telemedicine applications include consulting services by specialists at the University Clinical Hospital Center Rebro in Zagreb and at "Magdalena", a leading cardiology clinic in Croatia. After several years of experience with static high resolution ultrasonic digital immages for referral consulting diagnostics purposes, we now also use dynamic ultrasonic sequences in a project with the Department of Emmergency Gastroenterology at Rebro in Zagreb. The aim of the ongoing project is to compare the advantages and shortcomings in transmitting static ultrasonic digital immages and live sequences of ultrasonic examination in telematic diagnostics. Ultrasonic examination is a dynamic process in which the diagnostic accuracy is highly dependent on the dynamic moment of an ultrasound probe and signal. Our first results indicate that in diffuse parenchymal organ pathology the progression and the follow up of a disease is better presented to a remote consulting specialist by dynamic ultrasound sequences. However, the changes that involve only one part of a parenchymal organ can be suitably presented by static ultrasonic digital images alone. Furthermore, we need less time for digital imaging and such tele-consultations overall are more economical. Our previous telemedicine research and practice proved that we can greatly improve the level of medical care in remote healthcare facilities and cut healthcare costs considerably. The experience in the ongoing project points to a conclusion that we can further optimize remote diagnostics benefits by a right choice of telematic application thus reaching a

Ultrasonic flow meter

NARCIS (Netherlands)

Lötters, Joost Conrad; Snijders, G.J.; Volker, A.W.F.

2014-01-01

The invention relates to an ultrasonic flow meter comprising a flow tube for the fluid whose flow rate is to be determined. The flow meter comprises a transmitting element for emitting ultrasonic waves, which is provided on the outer jacket of the flow tube. A receiving element, which is provided on

Monitoring Protein Fouling on Polymeric Membranes Using Ultrasonic Frequency-Domain Reflectometry

Directory of Open Access Journals (Sweden)

Robin Fong

2011-08-01

Full Text Available Novel signal-processing protocols were used to extend the in situ sensitivity of ultrasonic frequency-domain reflectometry (UFDR for real-time monitoring of microfiltration (MF membrane fouling during protein purification. Different commercial membrane materials, with a nominal pore size of 0.2 µm, were challenged using bovine serum albumin (BSA and amylase as model proteins. Fouling induced by these proteins was observed in flat-sheet membrane filtration cells operating in a laminar cross-flow regime. The detection of membrane-associated proteins using UFDR was determined by applying rigorous statistical methodology to reflection spectra of ultrasonic signals obtained during membrane fouling. Data suggest that the total power reflected from membrane surfaces changes in response to protein fouling at concentrations as low as 14 μg/cm2, and results indicate that ultrasonic spectra can be leveraged to detect and monitor protein fouling on commercial MF membranes.

Ultrasonic Low-Friction Containment Plate for Thermal and Ultrasonic Stir Weld Processes

Science.gov (United States)

Graff, Karl; Short, Matt

2013-01-01

The thermal stir welding (TSW) process is finding applications in fabrication of space vehicles. In this process, workpieces to be joined by TSW are drawn, by heavy forces, between "containment plates," past the TSW tool that then causes joining of the separate plates. It is believed that the TSW process would be significantly improved by reducing the draw force, and that this could be achieved by reducing the friction forces between the workpieces and containment plates. Based on use of high-power ultrasonics in metal forming processes, where friction reduction in drawing dies has been achieved, it is believed that ultrasonic vibrations of the containment plates could achieve similar friction reduction in the TSW process. By applying ultrasonic vibrations to the containment plates in a longitudinal vibration mode, as well as by mounting and holding the containment plates in a specific manner such as to permit the plates to acoustically float, friction between the metal parts and the containment plates is greatly reduced, and so is the drawing force. The concept was to bring in the ultrasonics from the sides of the plates, permitting the ultrasonic hardware to be placed to the side, away from the equipment that contains the thermal stir tooling and that applies clamping forces to the plates. Tests demonstrated that one of the major objectives of applying ultrasonics to the thermal stir system, that of reducing draw force friction, should be achievable on a scaled-up system.

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

Amphetamine and environmentally induced hyperthermia differentially alter the expression of genes regulating vascular tone and angiogenesis in the meninges and associated vasculature.

Science.gov (United States)

Thomas, Monzy; George, Nysia I; Patterson, Tucker A; Bowyer, John F

2009-10-01

An amphetamine (AMPH) regimen that does not produce a prominent blood-brain barrier breakdown was shown to significantly alter the expression of genes regulating vascular tone, immune function, and angiogenesis in vasculature associated with arachnoid and pia membranes of the forebrain. Adult-male Sprague-Dawley rats were given either saline injections during environmentally-induced hyperthermia (EIH) or four doses of AMPH with 2 h between each dose (5, 7.5, 10, and 10 mg/kg d-AMPH, s.c.) that produced hyperthermia. Rats were sacrificed either 3 h or 1 day after dosing, and total RNA and protein was isolated from the meninges, arachnoid and pia membranes, and associated vasculature (MAV) that surround the forebrain. Vip, eNos, Drd1a, and Edn1 (genes regulating vascular tone) were increased by either EIH or AMPH to varying degrees in MAV, indicating that EIH and AMPH produce differential responses to enhance vasodilatation. AMPH, and EIH to a lesser extent, elicited a significant inflammatory response at 3 h as indicated by an increased MAV expression of cytokines Il1b, Il6, Ccl-2, Cxcl1, and Cxcl2. Also, genes related to heat shock/stress and disruption of vascular homeostasis such as Icam1 and Hsp72 were also observed. The increased expression of Ctgf and Timp1 and the decreased expression of Akt1, Anpep, and Mmp2 and Tek (genes involved in stimulating angiogenesis) from AMPH exposure suggest that angiogenesis was arrested or disrupted in MAV to a greater extent by AMPH compared to EIH. Alterations in vascular-related gene expression in the parietal cortex and striatum after AMPH were less in magnitude than in MAV, indicating less of a disruption of vascular homeostasis in these two regions. Changes in the levels of insulin-like growth factor binding proteins Igfbp1, 2, and 5 in MAV, compared to those in striatum and parietal cortex, imply an interaction between these regions to regulate the levels of insulin-like growth factor after AMPH damage. Thus, the

Computer automation of ultrasonic testing. [inspection of ultrasonic welding

Science.gov (United States)

Yee, B. G. W.; Kerlin, E. E.; Gardner, A. H.; Dunmyer, D.; Wells, T. G.; Robinson, A. R.; Kunselman, J. S.; Walker, T. C.

1974-01-01

Report describes a prototype computer-automated ultrasonic system developed for the inspection of weldments. This system can be operated in three modes: manual, automatic, and computer-controlled. In the computer-controlled mode, the system will automatically acquire, process, analyze, store, and display ultrasonic inspection data in real-time. Flaw size (in cross-section), location (depth), and type (porosity-like or crack-like) can be automatically discerned and displayed. The results and pertinent parameters are recorded.

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.)

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)

Ultrasonic inspection of austenitic welds

International Nuclear Information System (INIS)

Baikie, B.L.; Wagg, A.R.; Whittle, M.J.; Yapp, D.

1976-01-01

The ultrasonic examination of austenitic stainless steel weld metal has always been regarded as a difficult proposition because of the large and variable ultrasonic attenuations and back scattering obtained from apparently similar weld deposits. The work to be described shows how the existence of a fibre texture within each weld deposit (as a result of epitaxial growth through successive weld beads) produces a systematic variation in the ultrasonic attenuation coefficient and the velocity of sound, depending upon the angle between the ultrasonic beam and the fibre axis. Development work has shown that it is possible to adjust the welding parameters to ensure that the crystallographic texture within each weld is compatible with improved ultrasonic transmission. The application of the results to the inspection of a specific weld in type 316 weld metal is described

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.

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)

Irradiation Testing of Ultrasonic Transducers

International Nuclear Information System (INIS)

Daw, J.; Rempe, J.; Palmer, J.; Tittmann, B.; Reinhardt, B.; Kohse, G.; Ramuhalli, P.; Montgomery, R.; Chien, H.T.; Villard, J.F.

2013-06-01

Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of numerous parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. To address this need, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 10 21 n/cm 2 (E> 0.1 MeV). This test will be an instrumented lead test; and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. By characterizing magnetostrictive and piezoelectric transducer survivability during irradiation, test results will enable the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers. (authors)

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.

Ultrasonic dip seal maintenance system

International Nuclear Information System (INIS)

Poindexter, A.M.; Ricks, H.E.

1978-01-01

Disclosed is a system for removing impurities from the surfaces of liquid dip seals and for wetting the metal surfaces of liquid dip seals in nuclear components. The system comprises an ultrasonic transducer that transmits ultrasonic vibrations along an ultrasonic probe to the metal and liquid surfaces of the dip seal thereby loosening and removing those impurities

Grain fragmentation in ultrasonic-assisted TIG weld of pure aluminum.

Science.gov (United States)

Chen, Qihao; Lin, Sanbao; Yang, Chunli; Fan, Chenglei; Ge, Hongliang

2017-11-01

Under the action of acoustic waves during an ultrasonic-assisted tungsten inert gas (TIG) welding process, a grain of a TIG weld of aluminum alloy is refined by nucleation and grain fragmentation. Herein, effects of ultrasound on grain fragmentation in the TIG weld of aluminum alloy are investigated via systematic welding experiments of pure aluminum. First, experiments involving continuous and fixed-position welding are performed, which demonstrate that ultrasound can break the grain of the TIG weld of pure aluminum. The microstructural characteristics of an ultrasonic-assisted TIG weld fabricated by fixed-position welding are analyzed. The microstructure is found to transform from plane crystal, columnar crystal, and uniform equiaxed crystal into plane crystal, deformed columnar crystal, and nonuniform equiaxed crystal after application of ultrasound. Second, factors influencing ultrasonic grain fragmentation are investigated. The ultrasonic amplitude and welding current are found to have a considerable effect on grain fragmentation. The degree of fragmentation first increases and then decreases with an increase in ultrasonic amplitude, and it increases with an increase in welding current. Measurement results of the vibration of the weld pool show that the degree of grain fragmentation is related to the intensity of acoustic nonlinearity in the weld pool. The greater the intensity of acoustic nonlinearity, the greater is the degree of grain fragmentation. Finally, the mechanism of ultrasonic grain fragmentation in the TIG weld of pure aluminum is discussed. A finite element simulation is used to simulate the acoustic pressure and flow in the weld pool. The acoustic pressure in the weld pool exceeds the cavitation threshold, and cavitation bubbles are generated. The flow velocity in the weld pool does not change noticeably after application of ultrasound. It is concluded that the high-pressure conditions induced during the occurrence of cavitation, lead to grain

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.

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...

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.

An induction heating device using planar coil with high amplitude alternating magnetic fields for magnetic hyperthermia.

Science.gov (United States)

Wu, Zuhe; Zhuo, Zihang; Cai, Dongyang; Wu, Jian'an; Wang, Jie; Tang, Jintian

2015-01-01

Induction heating devices using the induction coil and magnetic nanoparticles (MNPs) are the way that the magnetic hyperthermia is heading. To facilitate the induction heating of in vivo magnetic nanoparticles in hyperthermia experiments on large animals. An induction heating device using a planar coil was designed with a magnetic field frequency of 328 kHz. The coil's magnetic field distribution and the device's induction heating performance on different concentrations of magnetic nanoparticles were measured. The alternating magnetic field produced in the axis position 165 mm away from the coil center is 40 Gs in amplitude; magnetic nanoparticles with a concentration higher than 80 mg. mL-1 can be heated up rapidly. Our results demonstrate that the device can be applied not only to in vitro and in small animal experiments of magnetic hyperthermia using MNPs, but also in large animal experiments.

Ultrasonic evaluation of the physical and mechanical properties of granites.

Science.gov (United States)

Vasconcelos, G; Lourenço, P B; Alves, C A S; Pamplona, J

2008-09-01

Masonry is the oldest building material that survived until today, being used all over the world and being present in the most impressive historical structures as an evidence of spirit of enterprise of ancient cultures. Conservation, rehabilitation and strengthening of the built heritage and protection of human lives are clear demands of modern societies. In this process, the use of nondestructive methods has become much common in the diagnosis of structural integrity of masonry elements. With respect to the evaluation of the stone condition, the ultrasonic pulse velocity is a simple and economical tool. Thus, the central issue of the present paper concerns the evaluation of the suitability of the ultrasonic pulse velocity method for describing the mechanical and physical properties of granites (range size between 0.1-4.0 mm and 0.3-16.5 mm) and for the assessment of its weathering state. The mechanical properties encompass the compressive and tensile strength and modulus of elasticity, and the physical properties include the density and porosity. For this purpose, measurements of the longitudinal ultrasonic pulse velocity with distinct natural frequency of the transducers were carried out on specimens with different size and shape. A discussion of the factors that induce variations on the ultrasonic velocity is also provided. Additionally, statistical correlations between ultrasonic pulse velocity and mechanical and physical properties of granites are presented and discussed. The major output of the work is the confirmation that ultrasonic pulse velocity can be effectively used as a simple and economical nondestructive method for a preliminary prediction of mechanical and physical properties, as well as a tool for the assessment of the weathering changes of granites that occur during the serviceable life. This is of much interest due to the usual difficulties in removing specimens for mechanical characterization.

The effect of hyperglycemia with or without hyperthermia on the radiation response of a spontaneous mouse fibrosarcoma

International Nuclear Information System (INIS)

Urano, M.; Todoroki, T.; Kahn, J.

1985-01-01

Hyperglycemia facilitates glycolysis with a resultant decrease in the tissue, particularly tumor pH. Another effect of hyperglycemia is to increase osmotic pressure in the extracellular fluid. The affect of hyperglycemia on the radiation response of our spontaneous tumor, FSa-II was examined. Further experiment includes the effect of hyperglycemia given 1 hour before local hyperthermia which was given in a 43.5 0 C water bath. Animals were C/sub 3/Hf/Sed mice from our defined flora colony. Tumor cell suspension was transplanted into the animal foot and the treatment was given when tumors reached an average diameter of 7 mm. Tumors were irradiated under clamped hypoxia, in air or under HPO (30 psi). Hyperglycemia, 5 mg/g given 1 hour before radiation, increased hypoxic cell fraction of the tumor without altering the slope fo the dose response curve. Hyperthermia enhanced the tumor response and increased hypoxic cell fraction. Further increase in the hypoxic cell fraction was noted following combined hyperglycemia and hyperthermia. Hyperthermia given 24 hours before radiation with or without glucose also increased hypoxic cell fraction, but decrease chronically hypoxic cell fraction (fraction not oxygenated under HPO)

Water bath hyperthermia is a simple therapy for psoriasis and also stimulates skin tanning in response to sunlight

Energy Technology Data Exchange (ETDEWEB)

Boreham, D.R.; Gasmann, H.C.; Mitchel, R.E.J

1994-07-01

An eight week trial, involving superficial hyperthermia delivered biweekly via simple water bath immersion, was tested for its ability to clear mild to moderate psoriatic lesions. Seven patients were treated and three cases rapidly improved. In the remaining patients, the treatment frequency was increased to alternate days; two cases improved significantly, one patient showed a partial response, and the fourth had no visible change (this was the only patient taking concurrent drug therapy - etretinate). In addition to resolving psoriatic lesions, water bath hyperthermia also reduced edema (swelling) and relieved pruritus (itching) in all patients, both during the treatment period and for up to several months after lesions had returned. Lesion reappearance occurred within one to three months after the last heat treatment. We retreated one patient and produced a second complete remission. These results indicate that simple repetitive water bath hyperthermia alone is effective in the treatment of psoriatic lesions in heatable locations. An unexpected side effect was enhanced melanin content (tanning) in all areas where hyperthermia treated skin was exposed to sunlight. (author)

The effect of hyperthermia and radiation on lysosomal enzyme activity of mouse mammary tumours

International Nuclear Information System (INIS)

Barratt, G.M.; Wills, E.D.

1979-01-01

The effects of hyperthermia and radiation have been studied on the acid phosphatase and β-glucuronidase activities in lysosomes of C3H mice mammary tumours and of the spleen. Quantitative histochemical methods have been used. Hyperthermic treatment of both spontaneous and transplanted tumours caused an increase in the activity of both acid phosphatase and β-glucuronase when measured immediately after treatment, but the activities returned to normal after 24 hours. In contrast a radiation dose of 3500 rad did not cause an increase in activity of either enzyme immediately, but a large activation was observed after 24 hr. Combination of hyperthermic and radiation treatment caused increases in enzyme activities which were dependent on the time after treatment. Hyperthermic treatment of the lower body of mice bearing tumours also caused activation of lysosomal enzymes in the spleen. This may be hormone mediated. It is considered that the increased lysosomal enzyme activity observed after hyperthermia may be a consequence of increased permeability of the lysosomal membrane caused by hyperthermia. (author)

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.

Ultrasonic neuromodulation

Science.gov (United States)

Naor, Omer; Krupa, Steve; Shoham, Shy

2016-06-01

Ultrasonic waves can be non-invasively steered and focused into mm-scale regions across the human body and brain, and their application in generating controlled artificial modulation of neuronal activity could therefore potentially have profound implications for neural science and engineering. Ultrasonic neuro-modulation phenomena were experimentally observed and studied for nearly a century, with recent discoveries on direct neural excitation and suppression sparking a new wave of investigations in models ranging from rodents to humans. In this paper we review the physics, engineering and scientific aspects of ultrasonic fields, their control in both space and time, and their effect on neuronal activity, including a survey of both the field’s foundational history and of recent findings. We describe key constraints encountered in this field, as well as key engineering systems developed to surmount them. In closing, the state of the art is discussed, with an emphasis on emerging research and clinical directions.

Cell biological effects of hyperthermia alone or combined with radiation or drugs : A short introduction to newcomers in the field

NARCIS (Netherlands)

Kampinga, HH

Hyperthermia results in protein unfolding that, if not properly chaperoned by Heat Shock Proteins (HSP), can lead to irreversible and toxic protein aggregates. Elevating HSP prior to heating makes cells thermotolerant. Hyperthermia also can enhance the sensitivity of cells to radiation and drugs.

Cellular radiation effects and hyperthermia: Cytokinetic investigations with stationary phase yeast cells

International Nuclear Information System (INIS)

Fingerhut, R.; Otto, F.; Oldiges, H.; Kiefer, J.

1980-01-01

Wild type diploid yeast, Saccharomyces cerevisiae strain 211, was subjected to 250 kV X-rays or 50 0 C heat treatment for 30 min or to a combination of both. X-ray exposure took place either in air or in nitrogen. Cell number, percentage of budding cells and cell cycle progression was followed for up to 12 h post irradiation. The distribution of cell cycle stages was determined by flow cytofluorometry. All treatments cause a retardation of cell division rate. Hyperthermia leads mainly to a lengthening of G 1 , whereas X-rays arrest the cells reversibly in G 2 . The effect of the combined treatment appears to be merely additive. No selective action of hyperthermia on hypoxic cells was found. (orig.) [de

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.

Ultrasonic colour Doppler imaging

DEFF Research Database (Denmark)

Evans, David H; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

2011-01-01

Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been...

Ultrasonic flowmeters

International Nuclear Information System (INIS)

Wittekind, W.D.

1979-01-01

A prototype ultrasonic flowmeter was assembled and tested. The theoretical basis of this prototype ultrasonic flowmeter is reviewed; the equipment requirements for a portable unit are discussed; the individual electronic modules contained in the prototype are described; the operating procedures and configuration are explained; and the data from preliminary calibrations are presented. The calibration data confirm that the prototype operates according to theoretical predictions and can indeed provide nonintrusive flow measurements to predicted accuracies for pipes larger than two inches, under single phase stable flow conditions

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.

In Vitro Investigation of the Individual Contributions of Ultrasound-Induced Stable and Inertial Cavitation in Targeted Drug Delivery.

Science.gov (United States)

Gourevich, Dana; Volovick, Alexander; Dogadkin, Osnat; Wang, Lijun; Mulvana, Helen; Medan, Yoav; Melzer, Andreas; Cochran, Sandy

2015-07-01

Ultrasound-mediated targeted drug delivery is a therapeutic modality under development with the potential to treat cancer. Its ability to produce local hyperthermia and cell poration through cavitation non-invasively makes it a candidate to trigger drug delivery. Hyperthermia offers greater potential for control, particularly with magnetic resonance imaging temperature measurement. However, cavitation may offer reduced treatment times, with real-time measurement of ultrasonic spectra indicating drug dose and treatment success. Here, a clinical magnetic resonance imaging-guided focused ultrasound surgery system was used to study ultrasound-mediated targeted drug delivery in vitro. Drug uptake into breast cancer cells in the vicinity of ultrasound contrast agent was correlated with occurrence and quantity of stable and inertial cavitation, classified according to subharmonic spectra. During stable cavitation, intracellular drug uptake increased by a factor up to 3.2 compared with the control. Reported here are the value of cavitation monitoring with a clinical system and its subsequent employment for dose optimization. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Pulsed ultrasonic stir welding system

Science.gov (United States)

Ding, R. Jeffrey (Inventor)

2013-01-01

An ultrasonic stir welding system includes a welding head assembly having a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. During a welding operation, ultrasonic pulses are applied to the rod as it rotates about its longitudinal axis. The ultrasonic pulses are applied in such a way that they propagate parallel to the longitudinal axis of the rod.

A new ultrasonic signal amplification method for detection of bacteria

Science.gov (United States)

Kant Shukla, Shiva; Resa López, Pablo; Sierra Sánchez, Carlos; Urréjola, José; Segura, Luis Elvira

2012-10-01

A new method is presented that increases the sensitivity of ultrasound-based techniques for detection of bacteria. The technique was developed for the detection of catalase-positive microorganisms. It uses a bubble trapping medium containing hydrogen peroxide that is mixed with the sample for microbiological evaluation. The enzyme catalase is present in catalase-positive bacteria, which induces a rapid hydrolysis of hydrogen peroxide, forming bubbles which remain in the medium. This reaction results in the amplification of the mechanical changes that the microorganisms produce in the medium. The effect can be detected by means of ultrasonic wave amplitude continuous measurement since the bubbles increase the ultrasonic attenuation significantly. It is shown that microorganism concentrations of the order of 105 cells ml-1 can be detected using this method. This allows an improvement of three orders of magnitude in the ultrasonic detection threshold of microorganisms in conventional culture media, and is competitive with modern rapid microbiological methods. It can also be used for the characterization of the enzymatic activity.

A new ultrasonic signal amplification method for detection of bacteria

International Nuclear Information System (INIS)

Shukla, Shiva Kant; López, Pablo Resa; Sánchez, Carlos Sierra; Segura, Luis Elvira; Urréjola, José

2012-01-01

A new method is presented that increases the sensitivity of ultrasound-based techniques for detection of bacteria. The technique was developed for the detection of catalase-positive microorganisms. It uses a bubble trapping medium containing hydrogen peroxide that is mixed with the sample for microbiological evaluation. The enzyme catalase is present in catalase-positive bacteria, which induces a rapid hydrolysis of hydrogen peroxide, forming bubbles which remain in the medium. This reaction results in the amplification of the mechanical changes that the microorganisms produce in the medium. The effect can be detected by means of ultrasonic wave amplitude continuous measurement since the bubbles increase the ultrasonic attenuation significantly. It is shown that microorganism concentrations of the order of 10 5 cells ml −1 can be detected using this method. This allows an improvement of three orders of magnitude in the ultrasonic detection threshold of microorganisms in conventional culture media, and is competitive with modern rapid microbiological methods. It can also be used for the characterization of the enzymatic activity. (paper)

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.

Ultrasonic stir welding process and apparatus

Science.gov (United States)

Ding, R. Jeffrey (Inventor)

2009-01-01

An ultrasonic stir welding device provides a method and apparatus for elevating the temperature of a work piece utilizing at least one ultrasonic heater. Instead of relying on a rotating shoulder to provide heat to a workpiece an ultrasonic heater is utilized to provide ultrasonic energy to the workpiece. A rotating pin driven by a motor assembly performs the weld on the workpiece. A handheld version can be constructed as well as a fixedly mounted embodiment.

Improvement of landfill leachate biodegradability with ultrasonic process.

Directory of Open Access Journals (Sweden)

Amir Hossein Mahvi

Full Text Available Landfills leachates are known to contain recalcitrant and/or non-biodegradable organic substances and biological processes are not efficient in these cases. A promising alternative to complete oxidation of biorecalcitrant leachate is the use of ultrasonic process as pre-treatment to convert initially biorecalcitrant compounds to more readily biodegradable intermediates. The objectives of this study are to investigate the effect of ultrasonic process on biodegradability improvement. After the optimization by factorial design, the ultrasonic were applied in the treatment of raw leachates using a batch wise mode. For this, different scenarios were tested with regard to power intensities of 70 and 110 W, frequencies of 30, 45 and 60 KHz, reaction times of 30, 60, 90 and 120 minutes and pH of 3, 7 and 10. For determining the effects of catalysts on sonication efficiencies, 5 mg/l of TiO(2 and ZnO have been also used. Results showed that when applied as relatively brief pre-treatment systems, the sonocatalysis processes induce several modifications of the matrix, which results in significant enhancement of its biodegradability. For this reason, the integrated chemical-biological systems proposed here represent a suitable solution for the treatment of landfill leachate samples.

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.

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

Imaging techniques for ultrasonic testing

International Nuclear Information System (INIS)

2013-01-01

These seminar proceedings contain 16 lectures on the following topics: 1. From imaging to quantification - ultrasound methods in medical diagnostics; 2. SAFT, TOFD, Phased Array - classical applications and recent developments in ultrasonic imaging; 3. Innovative ultrasonic imaging methods in research and application; 4. Industrial ultrasonic testing of fibre-reinforced structures of complex geometry; 5. Visualisation of crack tips in the inspection of wheel set shafts with longitudinal boreholes as a means of avoiding unnecessary wheel set changes; 6. Areal analysis of the propagation of Lamb waves on curved, anisotropic structures; 7. High-resolution representation in immersion technique testing; 8. Variants in generating images from phased array measurement data - practical examples involving copper, carbon-fibre reinforced plastic and other materials; 9. GIUM - an unconventional method of microstructure imaging using ultrasonic stimulation and laser vibrometry scanning; 10. Innovative air-ultrasonic testing concepts for improved imaging; 11. Use of imaging methods for improving the quality of test results from nondestructive testing; 12. Modelling and visualisation of EMUS stimulation for transducer optimisation; 13. Use of SAFT in the manufacture of energy conversion machines; 14. Ultrasonic imaging tests for improved defect characterisation during weld seam inspection on longitudinally welded large-diameter pipes; 15. SAFT reconstruction for testing austenitic weld seams and dissimilar metal weld seams for transverse cracks; 16. Imaging-based optimisation method for quantitative ultrasonic testing of anisotropic inhomogeneous austenitic welded joints with determination and utilisation of their elastic properties. One contribution has been abstracted separately. [de

The significance of accurate dielectric tissue data for hyperthermia treatment planning

NARCIS (Netherlands)

van de Kamer, J. B.; van Wieringen, N.; de Leeuw, A. A.; Lagendijk, J. J.

2001-01-01

For hyperthermia treatment planning, dielectric properties of several tissue types are required. Since it is difficult to perform patient specific dielectric imaging, default values based on literature data are used. However, these show a large spread (approximately 50%). Consequently, it is

Effect of melatonin on methamphetamine- and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced dopaminergic neurotoxicity and methamphetamine-induced behavioral sensitization.

Science.gov (United States)

Itzhak, Y; Martin, J L; Black, M D; Ali, S F

1998-06-01

Methamphetamine (METH)- and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic neurotoxicity is thought to be associated with the formation of free radicals. Since evidence suggests that melatonin may act as a free radical scavenger and antioxidant, the present study was undertaken to investigate the effect of melatonin on METH- and MPTP-induced neurotoxicity. In addition, the effect of melatonin on METH-induced locomotor sensitization was investigated. The administration of METH (5 mg kg(-1) x 3) or MPTP (20 mg kg(-1) x 3) to Swiss Webster mice resulted in 45-57% depletion in the content of striatal dopamine and its metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid, and 57-59% depletion in dopamine transporter binding sites. The administration of melatonin (10 mg kg(-1)) before each of the three injections of the neurotoxic agents (on day 1), and thereafter for two additional days, afforded a full protection against METH-induced depletion of dopamine and its metabolites and dopamine transporter binding sites. In addition, melatonin significantly diminished METH-induced hyperthermia. However, the treatment with melatonin had no significant effect on MPTP-induced depletion of the dopaminergic markers tested. In the set of behavioral experiments, we found that the administration of 1 mg kg(-1) METH to Swiss Webster mice for 5 days resulted in marked locomotor sensitization to a subsequent challenge injection of METH, as well as context-dependent sensitization (conditioning). The pretreatment with melatonin (10 mg kg(-1)) prevented neither the sensitized response to METH nor the development of conditioned locomotion. Results of the present study indicate that melatonin has a differential effect on the dopaminergic neurotoxicity produced by METH and MPTP. Since it is postulated that METH-induced hyperthermia is related to its neurotoxic effect, while regulation of body temperature is unrelated to MPTP-induced neurotoxicity or METH-induced

A novel polyol method to synthesize colloidal silver nanoparticles by ultrasonic irradiation.

Science.gov (United States)

Byeon, Jeong Hoon; Kim, Young-Woo

2012-01-01

A polyol synthesis of silver nanoparticles in the presence of ultrasonic irradiation was compared with other configurations (at ambient temperature, 120° C, and 120 °C with injected solutions) in the absence of ultrasonic irradiation in order to obtain systematic results for morphology and size distribution. For applying ultrasonic irradiation, rather fine and uniform spherical silver particles (21±3.7 nm) were obtained in a simple (at ambient temperature without mechanical stirring) and fast (within 4 min, 3.61×10(-3) mol min(-1)) manner than other cases (at ambient temperature (for 8 h, 0.03×10(-3) mol min(-1)): 86±16.8 nm, 120 °C (for 12 min, 1.16×10(-3) mol min(-1)): 64±14.9 nm, and 120 °C with injected solutions (during 12 min): 35±6.8 nm; all other cases contained anisotropic shaped particles). Even though the temperature of polyol reaction reached only at 80 °C (silver particle and surrounding components) by ultrasonic irradiation might induce a better formation kinetics and morphological uniformity. Copyright © 2011 Elsevier B.V. All rights reserved.

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

Full-field ultrasonic inspection for a composite sandwich plate skin-core debonding detection using laser-based ultrasonics

Science.gov (United States)

Chong, See Yenn; Victor, Jared J.; Todd, Michael D.

2017-04-01

In this paper, a full-field ultrasonic guided wave method is proposed to inspect a composite sandwich specimen made for an aircraft engine nacelle. The back skin/core interface of the specimen is built with two fabricated disbond defects (diameters of 12.7 mm and 25.4 mm) by removing areas of the adhesive used to bond the back skin to the core. A laser ultrasonic interrogation system (LUIS) incorporated with a disbond detection algorithm is developed. The system consists of a 1-kHz laser ultrasonic scanning system and a single fixed ultrasonic sensor to interrogate ultrasonic guided waves in the sandwich specimen. The interest area of 400 mm × 400 mm is scanned at a 0.5 mm scan interval. The corresponding full-field ultrasonic data is obtained and generated in the three-dimensional (3-D) space-time domain. Then, the 3-D full-field ultrasonic data is Fourier transformed and the ultrasonic frequency spectra are analyzed to determine the dominant frequency that is sensitive to the disbond defects. Continuous wavelet transform (CWT) based on fast Fourier transform (FFT) is implemented as a single-frequency bandpass filter to filter the full-field ultrasonic data in the 3-D space-time domain at the selected dominant frequency. The LUIS has shown the ability to detect the disbond with diameters of 11 mm and 23 mm which match to the pre-determined disbond sizes well. For future research, a robust signal processing algorithm and a model-based matched filter will be investigated to make the detection process autonomous and improve detectability

The improvement of ultrasonic characteristics in weld metal of austenitic stainless steel using magnetic stirring method

International Nuclear Information System (INIS)

Arakawa, T.; Tomisawa, Y.

1988-01-01

The magnetic stirring welding process was tested to save the difficulty of ultrasonic testing of austenitic stainless steel overlayed welds, due to grain refinement of weld solidification structure. The testing involved stirring the molten pool with Lorenz force induced by the interaction of welding current and alternative magnetic field applied from the outside magnetic coil. This report summarizes improvement of ultrasonic characteristic in austenitic stainless steel overlayed welds caused by magnetic stirring welding process

21 CFR 872.4850 - Ultrasonic scaler.

Science.gov (United States)

2010-04-01

... DEVICES DENTAL DEVICES Surgical Devices § 872.4850 Ultrasonic scaler. (a) Identification. An ultrasonic scaler is a device intended for use during dental cleaning and periodontal (gum) therapy to remove calculus deposits from teeth by application of an ultrasonic vibrating scaler tip to the teeth. (b...

Effect of hyperthermia and radiation on the cell cycle progression of HeLa cells

International Nuclear Information System (INIS)

Kubota, Nobuo

1982-01-01

The effect of hyperthermia and irradiation on cytokinetics was studied using exponentially growing HeLa cells. To determine the effect of heat and/or radiation on the cell cycle progression, the changes in the DNA distribution of the cell population after time intervals after treatment were studied. The cellular DNA content of the cell population was measured by flow cytometry. The results obtained were as follows: 1. Compared with the control, the cellular DNA content distribution of HeLa cells treated with 43 0 C for 20 min and 60 min showed cell accumulation in S and G 2 M phases 8 hours after treatment. 2. Hyperthermic treatment at 45 0 C for 20 min caused cells to accumulate in S phase in the first 4 hours and G 2 M phase after 8 to 14.5 hours, whereas heat treatment at 45 0 C for 60 min caused cells to accumulate in G 2 M phase after 24 hours. 3. Irradiation of exponentially growing cells induced a block in the progress from G 2 M to G 1 phase. 4. Dose survival curves of HeLa cells with and without postirradiation thermal treatment (43 0 C, 60 min) showed significant enhancement of radiosensitivity by hyperthermia. 5. The sequential treatment, i.e. 5 Gy irradiation followed immediately by heat treatment at 43 0 C for 60 min, caused more cells to accumulate in G 2 M phase after 24 and 48 hours, as compared with 5 Gy irradiation alone. (author)

The significance of accurate dielectric tissue data for hyperthermia treatment planning

NARCIS (Netherlands)

van de Kamer, JB; van Wieringen, N; de Leeuw, AAC; Lagendijk, JJW

2001-01-01

For hyperthermia treatment planning, dielectric properties of several tissue types are required. Since it is difficult to perform patient specific dielectric imaging, default values based on literature data are used. However, these show a large spread (approximate to 50%). Consequently, it is

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

Neo-adjuvant chemotherapy alone or with regional hyperthermia for localised high-risk soft-tissue sarcoma: a randomised phase 3 multicentre study

DEFF Research Database (Denmark)

Issels, Rolf D; Lindner, Lars H; Verweij, Jaap

2010-01-01

The optimum treatment for high-risk soft-tissue sarcoma (STS) in adults is unclear. Regional hyperthermia concentrates the action of chemotherapy within the heated tumour region. Phase 2 studies have shown that chemotherapy with regional hyperthermia improves local control compared with chemother...

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.

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.

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

Exposure to febrile-range hyperthermia potentiates Wnt signalling and epithelial-mesenchymal transition gene expression in lung epithelium.

Science.gov (United States)

Potla, Ratnakar; Tulapurkar, Mohan E; Luzina, Irina G; Atamas, Sergei P; Singh, Ishwar S; Hasday, Jeffrey D

2018-02-01

As environmental and body temperatures vary, lung epithelial cells experience temperatures significantly different from normal core temperature. Our previous studies in human lung epithelium showed that: (i) heat shock accelerates wound healing and activates profibrotic gene expression through heat shock factor-1 (HSF1); (ii) HSF1 is activated at febrile temperatures (38-41 °C) and (iii) hypothermia (32 °C) activates and hyperthermia (39.5 °C) reduces expression of a subset of miRNAs that target protein kinase-Cα (PKCα) and enhance proliferation. We analysed the effect of hypo- and hyperthermia exposure on Wnt signalling by exposing human small airway epithelial cells (SAECs) and HEK293T cells to 32, 37 or 39.5 °C for 24 h, then analysing Wnt-3a-induced epithelial-mesenchymal transition (EMT) gene expression by qRT-PCR and TOPFlash reporter plasmid activity. Effects of miRNA mimics and inhibitors and the HSF1 inhibitor, KNK437, were evaluated. Exposure to 39.5 °C for 24 h increased subsequent Wnt-3a-induced EMT gene expression in SAECs and Wnt-3a-induced TOPFlash activity in HEK293T cells. Increased Wnt responsiveness was associated with HSF1 activation and blocked by KNK437. Overexpressing temperature-responsive miRNA mimics reduced Wnt responsiveness in 39.5 °C-exposed HEK293T cells, but inhibitors of the same miRNAs failed to restore Wnt responsiveness in 32 °C-exposed HEK293T cells. Wnt responsiveness, including expression of genes associated with EMT, increases after exposure to febrile-range temperature through an HSF1-dependent mechanism that is independent of previously identified temperature-dependent miRNAs. This process may be relevant to febrile fibrosing lung diseases, including the fibroproliferative phase of acute respiratory distress syndrome (ARDS) and exacerbations of idiopathic pulmonary fibrosis (IPF).

Ultrasonic Bat Deterrent Technology

Energy Technology Data Exchange (ETDEWEB)

Kinzie, Kevin; Rominger, Kathryn M.

2017-12-14

The project objective was to advance the development and testing of an Near commercial bat-deterrent system with a goal to increase the current GE deterrent system effectiveness to over 50% with broad species applicability. Additionally, the research supported by this program has provided insights into bat behavior and ultrasonic deterrent design that had not previously been explored. Prior research and development had demonstrated the effectiveness of a commercial-grade, air-powered, ultrasonic bat deterrent to be between 30-50% depending upon the species of bat. However, the previous research provided limited insight into the behavioral responses of bats in the presence of ultrasonic deterrent sound fields that could be utilized to improve effectiveness. A unique bat flight room was utilized to observe the behavioral characteristics of bats in the presence of ultrasonic sound fields. Behavioral testing in the bat flight facility demonstrated that ultrasonic sounds similar to those produced by the GE deterrent influenced the activities and behaviors, primarily those associated with foraging, of the species exposed. The study also indicated that continuous and pulsing ultrasonic signals had a similar effect on the bats, and confirmed that as ultrasonic sounds attenuate, their influence on the bats’ activities and behavior decreases. Ground testing at Wolf Ridge Wind, LLC and Shawnee National Forest assessed both continuous and pulsing deterrent signals emitted from the GE deterrent system and further enhanced the behavioral understanding of bats in the presence of the deterrent. With these data and observations, the existing 4-nozzle continuous, or steady, emission ultrasonic system was redesigned to a 6-nozzle system that could emit a pulsing signal covering a larger air space around a turbine. Twelve GE 1.6-100 turbines were outfitted with the deterrent system and a formal three-month field study was performed using daily carcass searches beneath the 12

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.)

Nanosized As2O3/Fe2O3 complexes combined with magnetic fluid hyperthermia selectively target liver cancer cells.

Science.gov (United States)

Wang, Zi-Yu; Song, Jian; Zhang, Dong-Sheng

2009-06-28

To study the methods of preparing the magnetic nano-microspheres of Fe(2)O(3) and As(2)O(3)/Fe(2)O(3) complexes and their therapeutic effects with magnetic fluid hyperthermia (MFH). Nanospheres were prepared by chemical co-precipitation and their shape and diameter were observed. Hemolysis, micronucleus, cell viability, and LD(50) along with other in vivo tests were performed to evaluate the Fe(2)O(3) microsphere biocompatibility. The inhibition ratio of tumors after Fe(2)O(3) and As(2)O(3)/Fe(2)O(3) injections combined with induced hyperthermia in xenograft human hepatocarcinoma was calculated. Fe(2)O(3) and As(2)O(3)/Fe(2)O(3) particles were round with an average diameter of 20 nm and 100 nm as observed under transmission electron microscope. Upon exposure to an alternating magnetic field (AMF), the temperature of the suspension of magnetic particles increased to 41-51 degrees C, depending on different particle concentrations, and remained stable thereafter. Nanosized Fe(2)O(3) microspheres are a new kind of biomaterial without cytotoxic effects. The LD(50) of both Fe(2)O(3) and As(2)O(3)/Fe(2)O(3) in mice was higher than 5 g/kg. One to four weeks after Fe(2)O(3) and As(2)O(3)/Fe(2)O(3) complex injections into healthy pig livers, no significant differences were found in serum AST, ALT, BUN and Cr levels among the pigs of all groups (P > 0.05), and no obvious pathological alterations were observed. After exposure to alternating magnetic fields, the inhibition ratio of the tumors was significantly different from controls in the Fe(2)O(3) and As(2)O(3)/Fe(2)O(3) groups (68.74% and 82.79%, respectively; P < 0.01). Tumors of mice in treatment groups showed obvious necrosis, while normal tissues adjoining the tumor and internal organs did not. Fe(2)O(3) and As(2)O(3)/Fe(2)O(3) complexes exerted radiofrequency-induced hyperthermia and drug toxicity on tumors without any liver or kidney damage. Therefore, nanospheres are ideal carriers for tumor-targeted therapy.

Quality control of disinfection in ultrasonic baths

Energy Technology Data Exchange (ETDEWEB)

Schoene, H. [Technical University Dresden (Germany). Faculty of Mechanical Engineering; Jatzwauk, L. [University Hospital of the Technical University Dresden (Germany). Abt. Krankenhaushygiene

2002-07-01

Numerous investigations under laboratory conditions confirmed the microbicidal efficacy of ultrasonication. Morphological destruction was shown on bacteria and fungi as well as on different virus species. Ultrasonic treatment seems to increase the effect of different antibiotics and disinfectants. Reasons for this synergism are largely unknown and uninvestigated, but the active principle seems to bee the dispersing effect of ultrasonication in combination with the destruction of cell wall or cell membrane. Unfortunately no validation of test conditions exists for most of these investigations, regarding intensity and frequency of ultrasonic waves, temperature of liquid medium and measurement of cavitation which is an essential part of physical and chemical effects in ultrasonic baths. In contrast to most laboratory experiments sound density of ultrasound for treatment of medical instruments is below 1 W/cm{sup 2} because instruments will be destroyed under stronger ultrasonic conditions. The frequency is below 50 KHz. This paper describes bactericidal and fungicidal effects of low- intensity-ultrasonication and its synergistical support to chemical disinfection. (orig.)

Prospective phase II trial of regional hyperthermia and whole liver irradiation for numerous chemorefratory liver metastases from colerectal cancer

Energy Technology Data Exchange (ETDEWEB)

Yu, Jeong Il; Park, Hee Chul; Choi, Doo Ho [Dept. of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); and others

2016-03-15

A prospective phase II trial was conducted to evaluate the effectiveness and toxicity of regional hyperthermia and whole liver irradiation (WLI) for numerous chemorefractory liver metastases from colorectal cancer. Enrolled patients had numerous chemorefractory hepatic metastases from colorectal cancer. Five sessions of hyperthermia and seven fractions of 3-gray WLI were planned. Health-related quality of life (HRQoL) was determined using the Korean version of the European Organization for Research and Treatment of Cancer quality of life questionnaire C-30 and the Functional Assessment of Cancer Therapy-Hepatobiliary version 4.0. Objective and pain response was evaluated. A total of 12 patients consented to the study and the 10 who received WLI and hyperthermia were analyzed. WLI was completed as planned in nine patients and hyperthermia in eight. Pain response was partial in four patients and stable in four. Partial objective response was achieved in three patients (30.0%) and stable disease was seen in four patients at the 1-month follow-up. One patient died 1 month after treatment because of respiratory failure related to pleural metastasis progression. Other grade III or higher toxicities were detected in three patients; however, all severe toxicities were related to disease progression rather than treatment. No significant difference in HRQoL was noted at the time of assessment for patients who were available for questionnaires. Combined WLI and hyperthermia were well tolerated without severe treatment-related toxicity with a promising response from numerous chemorefractory hepatic metastases from colorectal cancer.

Cisplatin combined with hyperthermia kills HepG2 cells in intraoperative blood salvage but preserves the function of erythrocytes.

Science.gov (United States)

Yang, Jin-ting; Tang, Li-hui; Liu, Yun-qing; Wang, Yin; Wang, Lie-ju; Zhang, Feng-jiang; Yan, Min

2015-05-01

The safe use of intraoperative blood salvage (IBS) in cancer surgery remains controversial. Here, we investigated the killing effect of cisplatin combined with hyperthermia on human hepatocarcinoma (HepG2) cells and erythrocytes from IBS in vitro. HepG2 cells were mixed with concentrated erythrocytes and pretreated with cisplatin (50, 100, and 200 μg/ml) alone at 37 °C for 60 min and cisplatin (25, 50, 100, and 200 μg/ml) combined with hyperthermia at 42 °C for 60 min. After pretreatment, the cell viability, colony formation and DNA metabolism in HepG2 and the Na(+)-K(+)-ATPase activity, 2,3-diphosphoglycerate (2,3-DPG) concentration, free hemoglobin (Hb) level, osmotic fragility, membrane phosphatidylserine externalization, and blood gas variables in erythrocytes were determined. Pretreatment with cisplatin (50, 100, and 200 μg/ml) combined with hyperthermia (42 °C) for 60 min significantly decreased HepG2 cell viability, and completely inhibited colony formation and DNA metabolism when the HepG2 cell concentration was 5×10(4) ml(-1) in the erythrocyte (P2,3-DPG level, phosphatidylserine externalization, and extra-erythrocytic free Hb were significantly altered by hyperthermia plus high concentrations of cisplatin (100 and 200 μg/ml) (P0.05). In conclusion, pretreatment with cisplatin (50 μg/ml) combined with hyperthermia (42 °C) for 60 min effectively eliminated HepG2 cells from IBS but did not significantly affect erythrocytes in vitro.

Development and Application of an Ultrasonic Gas Flowmeter

International Nuclear Information System (INIS)

Hwang, Won Ho; Jeong, Hee Don; Park, Sang Gug; Jhang, Kyung Young

2002-01-01

This paper describes the development and the field application of the ultrasonic gas flowmeter for accurate measurement of the volumetric flow rate of gases in a harsh environmental conditions in iron and steel making company. This ultrasonic flowmeter is especially suited for measuring LDG, COG, BFG gases produced in iron and steel making process. This is a transit time type ultrasonic flowmeter. We have developed the transmitting and receiving algorithm of ultrasonic wave and the ultrasonic signal processing algorithm to develope a transit time type ultrasonic flowmeter. We have evaluated the performance of ultrasonic flowmeter by the calibration system with Venturi type standard flowmeter. We has confirmed its reliability by extensive field tests for a year in POSCO, iron and steel making company. Now we have developed the commercial model of ultrasonic flowmeter and applied to the POSCO gas line

Ultrasonic Tomography Imaging for Liquid-Gas Flow Measurement

Directory of Open Access Journals (Sweden)

Muhammad Jaysuman PUSPPANATHAN

2013-01-01

Full Text Available This research was carried out to measure two-phase liquid – gas flow regime by using a dual functionality ultrasonic transducer. Comparing to the common separated transmitter–receiver ultrasonic pairs transducer, the dual functionality ultrasonic transceiver is capable to produce the same measurable results hence further improvises and contributes to the hardware design improvement and system accuracy. Due to the disadvantages and the limitations of the separated ultrasonic transmitter–receiver pair, this paper presents a non-invasive ultrasonic tomography system using ultrasonic transceivers as an alternative approach. Implementation of ultrasonic transceivers, electronic measurement circuits, data acquisition system and suitable image reconstruction algorithms, the measurement of a liquid/gas flow was realized.

[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.

Effect of hyperthermia and misonidazole on the radiosensitivity of a transplant murine tumor: influence of factors modifying the fraction of hypoxic cells

International Nuclear Information System (INIS)

Wondergem, J.; Haveman, J.; van der Schueren, E.; van den Hoeven, H.; Breur, K.

1982-01-01

Hypoxia has been demonstrated to play an important role in the effect of hyperthermia on tumors. The influence of different factors modifying the oxygenation status of a transplantable murine mammary adenocarcinoma has been studied. The effect of hyperthermia alone on the tumor is not significantly influenced by the change in oxygenation status during the growth of the tumor. Also, the large increase of the acutely hypoxic cell fraction, as a result of anesthesia, does not change the effect of hyperthermia alone. In the combined irradiation-heat treatment there is a clear influence of the chronically hypoxic cell fraction on the response to hyperthermia: an increase in tumor size, resulting in a larger hypoxic cell fraction, leads to an increase in thermal enhancement ratio. However, the increased acutely hypoxic cell fraction, resulting from anesthesia, did not lead to an increase in thermal enhancement ratio; in fact the enhancement ratio apparently decreased. In spite of the fact that hyperthermia was applied immediately after irradiation no potentiation of radiation effects was found. The thermal enhancement of the radiation response was never larger than the enhancement as a result of misonidazole

Physical mechanism and modeling of heat generation and transfer in magnetic fluid hyperthermia through Néelian and Brownian relaxation: a review.

Science.gov (United States)

Suriyanto; Ng, E Y K; Kumar, S D

2017-03-23

Current clinically accepted technologies for cancer treatment still have limitations which lead to the exploration of new therapeutic methods. Since the past few decades, the hyperthermia treatment has attracted the attention of investigators owing to its strong biological rationales in applying hyperthermia as a cancer treatment modality. Advancement of nanotechnology offers a potential new heating method for hyperthermia by using nanoparticles which is termed as magnetic fluid hyperthermia (MFH). In MFH, superparamagnetic nanoparticles dissipate heat through Néelian and Brownian relaxation in the presence of an alternating magnetic field. The heating power of these particles is dependent on particle properties and treatment settings. A number of pre-clinical and clinical trials were performed to test the feasibility of this novel treatment modality. There are still issues yet to be solved for the successful transition of this technology from bench to bedside. These issues include the planning, execution, monitoring and optimization of treatment. The modeling and simulation play crucial roles in solving some of these issues. Thus, this review paper provides a basic understanding of the fundamental and rationales of hyperthermia and recent development in the modeling and simulation applied to depict the heat generation and transfer phenomena in the MFH.

Ultrasonic Stir Welding

Science.gov (United States)

Nabors, Sammy

2015-01-01

NASA Marshall Space Flight Center (MSFC) developed Ultrasonic Stir Welding (USW) to join large pieces of very high-strength metals such as titanium and Inconel. USW, a solid-state weld process, improves current thermal stir welding processes by adding high-power ultrasonic (HPU) energy at 20 kHz frequency. The addition of ultrasonic energy significantly reduces axial, frictional, and shear forces; increases travel rates; and reduces wear on the stir rod, which results in extended stir rod life. The USW process decouples the heating, stirring, and forging elements found in the friction stir welding process allowing for independent control of each process element and, ultimately, greater process control and repeatability. Because of the independent control of USW process elements, closed-loop temperature control can be integrated into the system so that a constant weld nugget temperature can be maintained during welding.

Development of coaxial ultrasonic probe for fatty liver diagnostic system using ultrasonic velocity change

Science.gov (United States)

Hori, Makoto; Yokota, Daiki; Aotani, Yuhei; Kumagai, Yuta; Wada, Kenji; Matsunaka, Toshiyuki; Morikawa, Hiroyasu; Horinaka, Hiromichi

2017-07-01

A diagnostic system for fatty liver at an early stage is needed because fatty liver is linked to metabolic syndrome. We have already proposed a fatty liver diagnosis method based on the temperature coefficient of ultrasonic velocity. In this study, we fabricated a coaxial ultrasonic probe by integrating two kinds of transducers for warming and signal detection. The diagnosis system equipped with the coaxial probe was applied to tissue-mimicking phantoms including the fat area. The fat content rates corresponding to the set rates of the phantoms were estimated by the ultrasonic velocity-change method.

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

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.)

Pitch-catch only ultrasonic fluid densitometer

Science.gov (United States)

Greenwood, M.S.; Harris, R.V.

1999-03-23

The present invention is an ultrasonic fluid densitometer that uses a material wedge and pitch-catch only ultrasonic transducers for transmitting and receiving ultrasonic signals internally reflected within the material wedge. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface. 6 figs.

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

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

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

Can magneto-plasmonic nanohybrids efficiently combine photothermia with magnetic hyperthermia?

Science.gov (United States)

Espinosa, Ana; Bugnet, Mathieu; Radtke, Guillaume; Neveu, Sophie; Botton, Gianluigi A.; Wilhelm, Claire; Abou-Hassan, Ali

2015-11-01

Multifunctional hybrid-design nanomaterials appear to be a promising route to meet the current therapeutics needs required for efficient cancer treatment. Herein, two efficient heat nano-generators were combined into a multifunctional single nanohybrid (a multi-core iron oxide nanoparticle optimized for magnetic hyperthermia, and a gold branched shell with tunable plasmonic properties in the NIR region, for photothermal therapy) which impressively enhanced heat generation, in suspension or in vivo in tumours, opening up exciting new therapeutic perspectives.Multifunctional hybrid-design nanomaterials appear to be a promising route to meet the current therapeutics needs required for efficient cancer treatment. Herein, two efficient heat nano-generators were combined into a multifunctional single nanohybrid (a multi-core iron oxide nanoparticle optimized for magnetic hyperthermia, and a gold branched shell with tunable plasmonic properties in the NIR region, for photothermal therapy) which impressively enhanced heat generation, in suspension or in vivo in tumours, opening up exciting new therapeutic perspectives. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06168g

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

performed, not only of the variance of thermal parameters with respect to clinical criteria such as toxicity, response, and survival but also its dependency on tumor characteristics. Results: The rate of resectability (89%) and response (59%) were high for the PRC group, and a clear positive correlation existed between index temperatures (T 90 ) and thermal doses (cum min T 90 ≥ 40.5 deg. C). Even though the overall 5-year survival was encouraging (60%) and significantly associated with response, there was no statistically significant relationship between temperature parameters and long-term survival for this limited number of patients. However, nonresectable tumors with higher thermal parameters (especially cum min T 90 ≥ 40.5 deg. C) had a tendency for better overall survival. We found even higher temperatures in patients with recurrences (T 90 = 40.7 deg. C versus T 90 = 40.2 deg. C). However, these conditions for easier heating did not involve a favorable clinical outcome, since surgical resectability (22%) and response rate (28%) for the RRC group were low. We did not notice any other dependency of thermal parameters to a specific tumor or patient characteristics. Finally, neither acute toxicity (hot spots) induced by hyperthermia or RCT nor perioperative morbidity were correlated with temperature-derived parameters. Only a higher probability for the occurrence of hot spots was found during treatment with elevated power levels. Conclusion: In this study with two subgroups, i.e., patients with PRC (n = 37) and RRC (n = 18), there exists a positive interrelationship between thermal parameters (such as T 90 , cum min T 90 ≥ 40,5 deg. C) and clinical parameters concerning effectiveness. Additional hyperthermia treatment does not seem to enhance toxicity or subacute morbidity. Procedures to measure temperatures and to derive thermal parameters, as well as the hyperthermia technique itself appear adequate enough to classify heat treatments in sessions as more or less

Ultrasonically assisted drilling: A finite-element model incorporating acoustic softening effects

International Nuclear Information System (INIS)

Phadnis, V A; Roy, A; Silberschmidt, V V

2013-01-01

Ultrasonically assisted drilling (UAD) is a novel machining technique suitable for drilling in hard-to-machine quasi-brittle materials such as carbon fibre reinforced polymer composites (CFRP). UAD has been shown to possess several advantages compared to conventional drilling (CD), including reduced thrust forces, diminished burr formation at drill exit and an overall improvement in roundness and surface finish of the drilled hole. Recently, our in-house experiments of UAD in CFRP composites demonstrated remarkable reductions in thrust-force and torque measurements (average force reductions in excess of 80%) when compared to CD with the same machining parameters. In this study, a 3D finite-element model of drilling in CFRP is developed. In order to model acoustic (ultrasonic) softening effects, a phenomenological model, which accounts for ultrasonically induced plastic strain, was implemented in ABAQUS/Explicit. The model also accounts for dynamic frictional effects, which also contribute to the overall improved machining characteristics in UAD. The model is validated with experimental findings, where an excellent correlation between the reduced thrust force and torque magnitude was achieved

Under sodium ultrasonic imaging system for PFBR

International Nuclear Information System (INIS)

Patankar, V.H.; Lalwani, S.K.; Agashe, A.A.

2014-01-01

Under Sodium UltraSonic Scanner (USUSS) has been developed to detect the growth and protrusion of fuel sub-assemblies of PFBR, submerged in liquid sodium by using the ultrasonic imaging technique during reactor shut-down when liquid sodium is at 180 ℃. The imaging is carried out prior to every Fuel handling operation. Electronics Division, BARC has designed and developed an 8-Channel Ultrasonic Imaging System (UIS) which consists of 4 downward viewing and 4 side viewing ultrasonic transducers alongwith pulser-receiver, signal processing electronics hardware and software. An automated mechanical scanner developed by IGCAR houses sodium immersible transducers to image the fuel sub assemblies. The system has been successfully tested with dummy protruding and grown FSAs, submerged under liquid sodium. Such ultrasonic imaging systems are not available to India from international market. The USUSS developed indigenously has all the features available in similar systems developed by other countries. After every imaging campaign, the mechanical scanner containing ultrasonic transducers is stored in the Argon filled storage-pit. Before every campaign of USUSS, it is necessary to check the healthiness of the sodium immersible and contaminated ultrasonic transducers, as the under-sodium scanner is decontaminated once in five years. For this purpose, a novel Non Contact Ultrasonic Inspection System (NCUIS) has been designed and developed by Electronics Division, BARC to check the functionality of the high-temperature and contaminated transducers of USUSS, using air-coupled ultrasonic technique. (author)

MWCNT-MnFe2O4 nanocomposite for efficient hyperthermia applications

Science.gov (United States)

Seal, Papori; Hazarika, Monalisa; Paul, Nibedita; Borah, J. P.

2018-04-01

In this work we present synthesis of multi-walled carbon nanotube (MWCNT)-Manganese ferrite (MnFe2O4) nanocomposite and its probable application in hyperthermia. MnFe2O4 nanoparticles were synthesized by co-precipitation method. X ray diffractogram (XRD) confirms the formation of cubic phase of MnFe2O4 with preferred crystallographic orientation along (311) plane. High resolution electron microscope (HRTEM) image of the composites confirms the presence of MnFe2O4 spherical nanoparticles on the surface of CNT which are bound strongly to the surface. MWCNT-MnFe2O4 nanocomposite were prepared after acid functionalization of MWCNT. Vibrational features of the synthesized samples were confirmed through Fourier transformed infra-red spectroscopy (FTIR). FTIR spectra of acid functionalized MWCNT shows a peak positioned at ˜1620cm-1 which corresponds to C=O functional group of carboxylic acid. Prepared MnFe2O4 nanoparticles and MWCNT-MnFe2O4 nanocomposites were subjected to hyperthermia studies.

Ultrasonic Linear Motor with Two Independent Vibrations

Science.gov (United States)

Muneishi, Takeshi; Tomikawa, Yoshiro

2004-09-01

We propose a new structure of an ultrasonic linear motor in order to solve the problems of high-power ultrasonic linear motors that drive the XY-stage for electron beam equipment and to expand the application fields of the motor. We pay special attention to the following three points: (1) the vibration in two directions of the ultrasonic linear motor should not influence mutually each other, (2) the vibration in two directions should be divided into the stage traveling direction and the pressing direction of the ultrasonic linear motor, and (3) the rigidity of the stage traveling direction of the ultrasonic linear motor should be increased. As a result, the supporting method of ultrasonic linear motors is simplified. The efficiency of the motor is improved and temperature rise is reduced. The stage position drift is also improved.

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.

Efficacy and limitations of hyperthermia using a 13.56 MHz radiofrequency capacitive heating system

International Nuclear Information System (INIS)

Kawamori, Jiro; Ito, Hideo; Kato, Ken-ichi; Hayasaka, Kazumasa; Saito, Tsutomu; Urahashi, Shingo; Tanaka, Yoshiaki

1996-01-01

Between August 1989 and June 1995, 123 patients were treated with hyperthermia using a 13.56 MHz RF capacitive heating system (HEH 500C/OMRON). Hyperthermia was combined with radiation therapy in 103 patients, with radiochemotherapy in 15 patients, with chemotherapy in 3 patients, and was used in 2 patients. Among the 123 patients, 92 completed hyperthermia and the remaining 31 discontinued it. Of these 31 patients, hyperthermia was discontinued because of local pain during heating in 22 cases and because of the poor general condition the remaining 9 patients. The initial response rate of the 92 patients completing therapy was 54.3%. CR, PR, NC and PD were achieved in 15, 35, 37, and 5 case, respectively. Initial response rates for head/neck, breast, and bone/soft tissue tumors were better than for other primary sites. The initial response rate for superficial tumors was better than that for deep seated tumors. Prognostic factors that significantly influenced the initial response rate were the radiation dose, number of heating sessions, tumor histology, and primary site. Concerning pain during heating, severe pain or discontinuation due to pain occurred were observed in 49 cases (39.8%). The factors having a significant correlation with pain during heating were applicator arrangement, applicator size, heating site, and tumor depth. In 24 patients, erosions or ulcers occurred (27.2%). The factors having a significant correlation with acute skin reactions, were applicator arrangement, applicator size, radiation therapy, tumor depth, and proximity to bone. In 12 cases, fat necrosis was observed (13%). Multiple regression analysis showed that the thickness of the subcutaneous fat, and the applicator arrangement had a significant correlation with the occurrence of fat necrosis. (K.H.)

Hyperthermia radiosensitization in human glioma cells comparison of recovery of polymerase activity, survival, and potentially lethal damage repair

International Nuclear Information System (INIS)

Raaphorst, G.P.; Feeley, M.M.

1994-01-01

DNA polymerase inactivation is compared to thermal radiosensitization and inhibition of damage recovery in human glioma cells. Two human glioma cell lines (U87MG and U373MG) were exposed to hyperthermia and irradiation. Hyperthermia was given at 43 degrees C and 45 degrees C and DNA polymerase α + δ + ε and β activities were measured. Hyperthermia was given at various times before irradiation and the degree of radiosensitization and polymerase activity was assessed at various times after heating. In addition the ability of cells to undergo repair of potentially lethal radiation damage was assessed for cells irradiated at various times after heating. Polymerase α + δ + ε and polymerase β both recovered after heating but polymerase β was faster and was complete in U373MG but not in the U87MG cell lines after 48 h incubation after heating (45 degrees C, 60 min). Incubation, between hyperthermia and irradiation resulted in a loss of radiosensitization and a loss of inhibition of repair of potentially lethal damage. These changes correlated well with recovery of polymerase β but not with polymerase α + δ + ε. The correlation of polymerase β activity and thermoradiosensitization and its recovery indicate that polymerase β may be one of the mechanisms involved in thermoradiosensitization. 35 refs., 7 figs

A JASTRO study group report. A randomized phase III trial of hyperthermia in combination with radiotherapy for superficial tumors

International Nuclear Information System (INIS)

Hiraoka, Masahiro; Nishimura, Yasumasa; Mitsumori, Michihide

1998-01-01

Result of study about local effect of hyperthermia in combination with radiotherapy for superficial tumors was reported. The irradiation was more than 90% isodose for lesion, and total dose was 60 Gy in cases with anamnesis and 40-50 Gy and without anamnesis at a rate of five times a week and 2 Gy at one time. Hyperthermia was carried out four times; once a week, at 42.5 degrees on tumor side edge, and for 40 minutes. Total 53 cases (neck lymph node metastasis 30 cases, relapse breast cancer 11, advanced breast cancer 1, other superficial tumor 11) were divided into 2 groups. Radiotherapy without hyperthermia (group R) was 27 cases, radiotherapy with hyperthermia (group H) was 26 cases. CR and CR+PR within 2 months after treatment were as follows: Group R: 50%, 85%, Group H: 64%, 100%. The CR+PR was superior in group H (p=0.0497). The CR at maximum effect after treatment was 65% of group R and 86% of group H (p=0.17). The local control rate after CR was not different in both groups. (K.H.)

Highly accurate adaptive TOF determination method for ultrasonic thickness measurement

Science.gov (United States)

Zhou, Lianjie; Liu, Haibo; Lian, Meng; Ying, Yangwei; Li, Te; Wang, Yongqing

2018-04-01

Determining the time of flight (TOF) is very critical for precise ultrasonic thickness measurement. However, the relatively low signal-to-noise ratio (SNR) of the received signals would induce significant TOF determination errors. In this paper, an adaptive time delay estimation method has been developed to improve the TOF determination’s accuracy. An improved variable step size adaptive algorithm with comprehensive step size control function is proposed. Meanwhile, a cubic spline fitting approach is also employed to alleviate the restriction of finite sampling interval. Simulation experiments under different SNR conditions were conducted for performance analysis. Simulation results manifested the performance advantage of proposed TOF determination method over existing TOF determination methods. When comparing with the conventional fixed step size, and Kwong and Aboulnasr algorithms, the steady state mean square deviation of the proposed algorithm was generally lower, which makes the proposed algorithm more suitable for TOF determination. Further, ultrasonic thickness measurement experiments were performed on aluminum alloy plates with various thicknesses. They indicated that the proposed TOF determination method was more robust even under low SNR conditions, and the ultrasonic thickness measurement accuracy could be significantly improved.

Pulsed ultrasonic stir welding method

Science.gov (United States)

Ding, R. Jeffrey (Inventor)

2013-01-01

A method of performing ultrasonic stir welding uses a welding head assembly to include a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. In the method, the rod is rotated about its longitudinal axis during a welding operation. During the welding operation, a series of on-off ultrasonic pulses are applied to the rod such that they propagate parallel to the rod's longitudinal axis. At least a pulse rate associated with the on-off ultrasonic pulses is controlled.

Use of ultrasonic waves in sub-cooled boiling

International Nuclear Information System (INIS)

Bartoli, Carlo; Baffigi, Federica

2012-01-01

This work focuses on the use of ultrasounds in heat transfer fields. Under particular conditions, ultrasonic waves induce a convection coefficient increase. This initial research work, indicates that there are some practical applications in the cooling of the latest generation electronic components. In the first part of this paper, some background on this subject is reported. The ultrasound's influence on heat transfer rate has been observed since the 60's: different authors studied the cooling effect due to ultrasonic waves from different heat transfer regimes. The most investigated configuration was a thin platinum wire immersed in water. Later, a bibliographic research on possible practical applications of ultrasounds was carried out. This research focused in particular on the issue for 3D highly integrated electronic components. For these systems the thermal problem is a major challenge, because they cannot exceed critical temperatures, after which they could be damaged irreversibly. On the basis of our experimental results, ultrasounds could represent a valid means to overcome these thermal problems. Finally, the paper presents a series of experiments performed in the Thermal-Fluid- Dynamic Lab at the Energy and Engineering Systems Department of University of Pisa. The experiments provide systematic evidence of ultrasonic waves effects, on free convection heat transfer, from a heated circular cylinder to sub-cooled water, at atmospheric pressure. Many variables involved in the heat transfer rise were tested, for example: the ultrasonic generator's power, the position of the heater inside the ultrasonic tank, the variation of the water sub-cooling degree, as function of the heat flux needed dissipating. The aim of the experiment was to find out the set of optimal conditions, in order to successively apply all the results to real packaging systems, as mentioned before. The maximum increase in the heat transfer coefficient, due to ultrasonic waves, was 57

Ultrasonic tests. Pt. 2

International Nuclear Information System (INIS)

Goebbels, K.

1980-01-01

After a basic treatment of ultrasonic wave propagation, of the state-of-the-art methods and the technical background in the preceeding part, advanced ultrasonic NDT techniques are presented here. The discussion of new development includes - manipulation systems, - automation of ultrasonic testing methods, documentation and evaluation. In the middle of this part the main problem areas will be discussed: - detection of defects (e.g. in coarse grained structures and welds), - classification of defects (e.g. discrimination between crack-like and volumetric faults), - sizing of defects. Research in the field of acoustical holography, development of probes and phased arrays, electromagnetic acoustic transducers and signal enhancement are the main contributing parts to the report. (orig./RW)

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)

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.

A forward model and conjugate gradient inversion technique for low-frequency ultrasonic imaging.

Science.gov (United States)

van Dongen, Koen W A; Wright, William M D

2006-10-01

Emerging methods of hyperthermia cancer treatment require noninvasive temperature monitoring, and ultrasonic techniques show promise in this regard. Various tomographic algorithms are available that reconstruct sound speed or contrast profiles, which can be related to temperature distribution. The requirement of a high enough frequency for adequate spatial resolution and a low enough frequency for adequate tissue penetration is a difficult compromise. In this study, the feasibility of using low frequency ultrasound for imaging and temperature monitoring was investigated. The transient probing wave field had a bandwidth spanning the frequency range 2.5-320.5 kHz. The results from a forward model which computed the propagation and scattering of low-frequency acoustic pressure and velocity wave fields were used to compare three imaging methods formulated within the Born approximation, representing two main types of reconstruction. The first uses Fourier techniques to reconstruct sound-speed profiles from projection or Radon data based on optical ray theory, seen as an asymptotical limit for comparison. The second uses backpropagation and conjugate gradient inversion methods based on acoustical wave theory. The results show that the accuracy in localization was 2.5 mm or better when using low frequencies and the conjugate gradient inversion scheme, which could be used for temperature monitoring.

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.

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.

Detailed simulation of ultrasonic inspections

International Nuclear Information System (INIS)

Chaplin, K.R.; Douglas, S.R.; Dunford, D.

1997-01-01

Simulation of ultrasonic inspection of engineering components have been performed at the Chalk River Laboratories of AECL for over 10 years. The computer model, called EWE for Elastic Wave Equations, solves the Elastic Wave Equations using a novel finite difference scheme. It simulates the propagation of an ultrasonic wave from the transducer to a flaw, the scatter of waves from the flaw, and measurement of signals at a receive transducer. Regions of different materials, water and steel for example, can be simulated. In addition, regions with slightly different material properties from the parent material can be investigated. The two major types of output are displays of the ultrasonic waves inside the component and the corresponding A-scans. EPRI and other organizations have used ultrasonic models for: defining acceptable ultrasonic inspection procedures, designing and evaluating inspection techniques, and for quantifying inspection reliability. The EWE model has been applied to the inspection of large pipes in a nuclear plant, gas pipeline welds and steam generator tubes. Most recent work has dealt with the ultrasonic inspection of pressure tubes in CANDU reactors. Pressure tube inspections can reliably detect and size defects; however, there are improvements that can be made. For example, knowing the sharpness of a flaw-tip is crucial for fitness for service assessments. Computer modelling of the ultrasonic inspection of flaws with different root radius has suggested inspection techniques that provide flaw tip radius information. A preliminary investigation of these methods has been made in the laboratory. The basis for the model will be reviewed at the presentation. Then the results of computer simulations will be displayed on a PC using an interactive program that analyzes simulated A-scans. This software tool gives inspection staff direct access to the results of computer simulations. (author)

The effects of ultrasonic solidification on aluminum

OpenAIRE

Đorđević Slavko 1

2003-01-01

The effect of ultrasound on characteristics of solidified aluminum was shown. An ultrasonic head and ultrasonic system for modification was designed and applied to the crystallizing aluminum melt. The ultrasonic generator allows power of 50-500 W, amplitude of oscillations 10-100 um.m and the operating frequency of 25 kHz. Ultrasonic modification was done by ultrasound introduced from above into the melt. Microstructure photographs show decreasing of the grain size more than five times.

The effects of ultrasonic solidification on aluminum

Directory of Open Access Journals (Sweden)

Đorđević Slavko 1

2003-01-01

Full Text Available The effect of ultrasound on characteristics of solidified aluminum was shown. An ultrasonic head and ultrasonic system for modification was designed and applied to the crystallizing aluminum melt. The ultrasonic generator allows power of 50-500 W, amplitude of oscillations 10-100 um.m and the operating frequency of 25 kHz. Ultrasonic modification was done by ultrasound introduced from above into the melt. Microstructure photographs show decreasing of the grain size more than five times.

Case studies in ultrasonic testing

International Nuclear Information System (INIS)

Prasad, V.; Satheesh, C.; Varde, P.V.

2015-01-01

Ultrasonic testing is widely used Non Destructive Testing (NDT) method and forms the essential part of In-service inspection programme of nuclear reactors. Main application of ultrasonic testing is for volumetric scanning of weld joints followed by thickness gauging of pipelines and pressure vessels. Research reactor Dhruva has completed the first In Service Inspection programme in which about 325 weld joints have been volumetrically scanned, in addition to thickness gauging of 300 meters of pipe lines of various sizes and about 24 nos of pressure vessels. Ultrasonic testing is also used for level measurements, distance measurements and cleaning and decontamination of tools. Two case studies are brought out in this paper in which ultrasonic testing is used successfully for identification of butterfly valve opening status and extent of choking in pipe lines in Dhruva reactor systems

Internal ultrasonic inspection of flexible pipe

Energy Technology Data Exchange (ETDEWEB)

Baltzersen, O. (IKU Petroleumsforskning A/S, Trondheim (Norway) Norwegian Inst. of Tech., Trondheim (Norway). Div. of Petroleum Engineering and Applied Geophysics); Waag, T.I. (IKU Petroleumsforskning A/S, Trondheim (Norway))

1993-10-01

Methods for internal ultrasonic inspection of flexible pipe have been investigated through experiments with a short sample of Coflexip pipe. Ultrasonic backscatter methods using normal and non-normal incidence have been used for qualitative high contrast ultrasonic imaging of the inner surface of the pipe. Analysis of the internal cross-section has been performed based on the use of a non-contact ultrasonic caliper, and processing procedures which enable calculation of, and compensation for, eccentricity of the tool in the pipe. The methods developed can be used to quantitatively estimate the thickness of the internal carcass, and perform high resolution topographic mapping of the inner surface. (Author)

Stresses in ultrasonically assisted bone cutting

International Nuclear Information System (INIS)

Alam, K; Mitrofanov, A V; Silberschmidt, V V; Baeker, M

2009-01-01

Bone cutting is a frequently used procedure in the orthopaedic surgery. Modern cutting techniques, such as ultrasonic assisted drilling, enable surgeons to perform precision operations in facial and spinal surgeries. Advanced understanding of the mechanics of bone cutting assisted by ultrasonic vibration is required to minimise bone fractures and to optimise the technique performance. The paper presents results of finite element simulations on ultrasonic and conventional bone cutting analysing the effects of ultrasonic vibration on cutting forces and stress distribution. The developed model is used to study the effects of cutting and vibration parameters (e.g. amplitude and frequency) on the stress distributions in the cutting region.

Ultrasonic imaging of projected components of PFBR

Energy Technology Data Exchange (ETDEWEB)

Sylvia, J.I., E-mail: sylvia@igcar.gov.in [Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Jeyan, M.R.; Anbucheliyan, M.; Asokane, C.; Babu, V. Rajan; Babu, B.; Rajan, K.K.; Velusamy, K.; Jayakumar, T. [Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India)

2013-05-15

Highlights: ► Under sodium ultrasonic scanner in PFBR is for detecting protruding objects. ► Feasibility study for detecting Absorber rods and its drive mechanisms. ► Developed in-house PC based ultrasonic imaging system. ► Different case studies were carried out on simulated ARDM's. ► Implemented the experimental results to PFBR application. -- Abstract: The 500 MWe, sodium cooled, Prototype Fast Breeder Reactor (PFBR) is under advanced stage of construction at Kalpakkam in India. Opacity of sodium restricts visual inspection of components immersed in sodium by optical means. Ultrasonic wave passes through sodium hence ultrasonic techniques using under sodium ultrasonic scanners are developed to obtain under sodium images. The main objective of such an Under Sodium Ultrasonic Scanner (USUSS) for Prototype Fast Breeder Reactor (PFBR) is to detect and ensure that no core Sub Assembly (SA) or Absorber Rod or its Drive Mechanism is protruded in the above core plenum before starting the fuel handling operation. Hence, it is necessary to detect and locate the object, if it is protruding the above core plenum. To study the feasibility of detecting the absorber rods and their drive mechanisms using direct ultrasonic imaging technique, experiments were carried out for different orientations and profiles of the projected components in a 5 m diameter water tank. The in-house developed PC based ultrasonic scanning system is used for acquisition and analysis of data. The pseudo three dimensional color images obtained are discussed and the results are applicable for PFBR. This paper gives the details of the features of the absorber rods and their drive mechanisms, their orientation in the reactor core, experimental setup, PC based ultrasonic scanning system, ultrasonic images and the discussion on the results.

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.

Fundamentals of ultrasonic phased arrays

CERN Document Server

Schmerr, Lester W

2014-01-01

This book describes in detail the physical and mathematical foundations of ultrasonic phased array measurements.?The book uses linear systems theory to develop a comprehensive model of the signals and images that can be formed with phased arrays. Engineers working in the field of ultrasonic nondestructive evaluation (NDE) will find in this approach a wealth of information on how to design, optimize and interpret ultrasonic inspections with phased arrays. The fundamentals and models described in the book will also be of significant interest to other fields, including the medical ultrasound and

Superparamagnetic iron oxide nanoparticles incorporated into silica nanoparticles by inelastic collision via ultrasonic field: Role of colloidal stability

Energy Technology Data Exchange (ETDEWEB)

Sodipo, Bashiru Kayode; Azlan, Abdul Aziz [Nano-Optoelectronics Research and Technology (NOR) Lab, School of Physics, Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia Nano-Biotechnology Research (Malaysia); Innovation (NanoBRI), Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800, Pulau Pinang (Malaysia)

2015-04-24

Superparamagnetic iron oxide nanoparticles (SPION)/Silica composite nanoparticles were prepared by ultrasonically irradiating colloidal suspension of silica and SPION mixture. Both silica and SPION were synthesized independently via co-precipitation and sol-gel method, respectively. Their mixtures were sonicated at different pH between 3 and 5. Electrophoresis measurement and other physicochemical analyses of the products demonstrate that at lower pH SPION was found incorporated into the silica. However, at pH greater than 4, SPION was unstable and unable to withstand the turbulence flow and shock wave from the ultrasonic field. Results suggest that the formation of the SPION/silica composite nanoparticles is strongly related to the inelastic collision induced by ultrasonic irradiation. More so, the formation the composite nanoparticles via the ultrasonic field are dependent on the zeta potential and colloidal stability of the particles.

Study on the usefulness of high-frequency analysis of the combined treatment of cancer with hyperthermia

International Nuclear Information System (INIS)

Ji, Youn Sang; Dong, Kyung Rae; Yeo, Hwa Yeon

2016-01-01

In order to understand the usefulness to the high-frequency thermal therapy of cancer staging according to the TNM classification treatment, was to evaluate the effect of high frequency hyperthermia treatment approach through other means and whether other organs, according to the combined presence of transition. Targeted to receive more than a total of 1 cycle high frequency heat treatment at C hospital that performed the high-frequency hyperthermia cancer patients 92 people out stage, depending on the presence or absence of metastasis, combined hyperthermia patients for statistics before and after treatment the therapeutic effect of the therapeutic classification. Out of a total of 92 patients decrease 11 patients, stable 71 patients, with increase 10 patients, the rate of increase is the result of about 11% patients showed a decrease of about 89% is occupied by patients and a stable rate. There is strong evidence for the usefulness as a secondary therapy to maintain the quality of life, while slowing the progression of cancer by a high-frequency heat treatment

Study on the usefulness of high-frequency analysis of the combined treatment of cancer with hyperthermia

Energy Technology Data Exchange (ETDEWEB)

Ji, Youn Sang; Dong, Kyung Rae [Dept. of Radiological Technology, Gwangju Health University, Gwangju (Korea, Republic of); Yeo, Hwa Yeon [Dept. of of Radiology, Nambu University, Gwangju (Korea, Republic of)

2016-11-15

In order to understand the usefulness to the high-frequency thermal therapy of cancer staging according to the TNM classification treatment, was to evaluate the effect of high frequency hyperthermia treatment approach through other means and whether other organs, according to the combined presence of transition. Targeted to receive more than a total of 1 cycle high frequency heat treatment at C hospital that performed the high-frequency hyperthermia cancer patients 92 people out stage, depending on the presence or absence of metastasis, combined hyperthermia patients for statistics before and after treatment the therapeutic effect of the therapeutic classification. Out of a total of 92 patients decrease 11 patients, stable 71 patients, with increase 10 patients, the rate of increase is the result of about 11% patients showed a decrease of about 89% is occupied by patients and a stable rate. There is strong evidence for the usefulness as a secondary therapy to maintain the quality of life, while slowing the progression of cancer by a high-frequency heat treatment.

Mathematical modelling of the destruction degree of cancer under the influence of a RF hyperthermia

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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.

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

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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.

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

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

Long duration mild temperature hyperthermia and brachytherapy.

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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.

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.

Method and apparatus to characterize ultrasonically reflective contrast agents

Science.gov (United States)

Pretlow, Robert A., III (Inventor)

1993-01-01

A method and apparatus for characterizing the time and frequency response of an ultrasonically reflective contrast agent is disclosed. An ultrasonically reflective contrast agent is injected, under constant pressure, into a fluid flowing through a pump flow circuit. The fluid and the ultrasonically reflective contrast agent are uniformly mixed in a mixing chamber, and the uniform mixture is passed through a contrast agent chamber. The contrast agent chamber is acoustically and axially interposed between an ultrasonic transducer chamber and an acoustic isolation chamber. A pulse of ultrasonic energy is transmitted into the contrast agent chamber from the ultrasonic transducer chamber. An echo waveform is received from the ultrasonically reflective contrast agent, and it is analyzed to determine the time and frequency response of the ultrasonically reflective contrast agent.

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

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

Improvement of Ultrasonic Distance Measuring System

Directory of Open Access Journals (Sweden)

Jiang Yu

2018-01-01

Full Text Available This paper mainly introduces a kind of ultrasonic distance measuring system with AT89C51 single chip as the core component. The paper expounds the principle of ultrasonic sensor and ultrasonic ranging, hardware circuit and software program, and the results of experiment and analysis.The hardware circuit based on SCM, the software design adopts the advanced microcontroller programming language.The amplitude of the received signal and the time of ultrasonic propagation are regulated by closed loop control. [1,2]The double closed loop control technology for amplitude and time improves the measuring accuracy of the instrument. The experimental results show that greatly improves the measurement accuracy of the system.

Ultrasonic Histotripsy for Tissue Therapy

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

2015-01-01

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

Ultrasonic Histotripsy for Tissue Therapy

International Nuclear Information System (INIS)

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

2015-01-01

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

Ultrasonic tests on materials with protective coatings

International Nuclear Information System (INIS)

Whaley, H.L.

1977-01-01

Protective coatings are applied to some nuclear components such as reactor vessels to inhibit surface corrosion. Since in-service ultrasonic inspection is required for such components, a study was performed to determine whether the use of protective coatings can affect ultrasonic tests. Two 2 in. thick steel plates were uniformly machined, sandblasted, and used as bases for two types of protective coatings. The type and thickness of the coating and the presence of contamination, such as fingerprints or mild oxidation under the paint, were the independent variables associated with the coating. Tests were run to determine the effects of the protective coatings on ultrasonic tests conducted on the steel plates. Significant variations in ultrasonic test sensitivity occurred as a function of the type and thickness of protective coating, couplant (material that conducts the ultrasound from the transducer into the test part, normally water or some type of oil), transducer wear plate, and ultrasonic test frequency. Ultrasonic tests can be strongly affected by a protective coating on the component to be inspected. As compared to the test sensitivity for an uncoated reference sample, the sensitivity may be dramatically shifted up or down on the coated surface. In certain coating thickness ranges, the sensitivity can fluctuate widely with small changes in coating thickness. If a coating is chosen properly, however, components with protective coatings can be tested ultrasonically with valid results. These results are for the case of ultrasonic input on the coated surface. It is not expected that an ultrasonic test conducted from the front surface would be appreciably affected by a coating on the rear surface

Rib fractures after reirradiation plus hyperthermia for recurrent breast cancer: Predictive factors

NARCIS (Netherlands)

Oldenborg, Sabine; Valk, Christel; van Os, Rob; Oei, Bing; Venselaar, Jack; Vörding, Paul Zum Vörde Sive; van Randen, Adriënne; Crezee, Hans; van Tienhoven, Geertjan; Rasch, Coen

2016-01-01

Combining reirradiation (reRT) and hyperthermia (HT) has shown high therapeutic value for patients with locoregional recurrent breast cancer (LR). However, additional toxicity of reirradiation (e.g., rib fractures) may occur. The aim of this study is to determine the impact of potential risk factors

Ultrasonic propulsion of kidney stones.

Science.gov (United States)

May, Philip C; Bailey, Michael R; Harper, Jonathan D

2016-05-01

Ultrasonic propulsion is a novel technique that uses short bursts of focused ultrasonic pulses to reposition stones transcutaneously within the renal collecting system and ureter. The purpose of this review is to discuss the initial testing of effectiveness and safety, directions for refinement of technique and technology, and opinions on clinical application. Preclinical studies with a range of probes, interfaces, and outputs have demonstrated feasibility and consistent safety of ultrasonic propulsion with room for increased outputs and refinement toward specific applications. Ultrasonic propulsion was used painlessly and without adverse events to reposition stones in 14 of 15 human study participants without restrictions on patient size, stone size, or stone location. The initial feasibility study showed applicability in a range of clinically relevant situations, including facilitating passage of residual fragments following ureteroscopy or shock wave lithotripsy, moving a large stone at the ureteropelvic junction with relief of pain, and differentiating large stones from a collection of small fragments. Ultrasonic propulsion shows promise as an office-based system for transcutaneously repositioning kidney stones. Potential applications include facilitating expulsion of residual fragments following ureteroscopy or shock wave lithotripsy, repositioning stones prior to treatment, and repositioning obstructing ureteropelvic junction stones into the kidney to alleviate acute renal colic.

Depression of DNA synthesis rate following hyperthermia, gamma irradiation, cyclotron neutrons and mixed modalities

International Nuclear Information System (INIS)

Weber, H.J.; Muehlensiepen, H.; Porschen, W.; Feinendegen, L.E.; Dietzel, F.

1978-01-01

The incorporation of the thymidine analogue I-UdR is proportional to the activity of DNA synthesis. The maximum depression of 125-I-UdR incorporation occurs approximately 4 hours after all kinds of treatment. The increase which follow reflects cell processes like reoxygeneration, recovery, recycling and recruitment (although a direct relation is not yet demonstrable). The degree of depression 4 hours after treatment and the time required needs to reach control level is dependent on dose and radiation quaility but no such dependence could be clearly seen for the times of hyperthermia treatment we used. Neutron irradiation and the combination gamma irradiation + hyperthermia show a higher depression and a slower return to normal than gamma irradiation at the same dose. (orig.) [de

Effects of 42 deg. C hyperthermia on intracellular pH in ovarian carcinoma cells during acute or chronic exposure to low extracellular pH

International Nuclear Information System (INIS)

Wahl, Miriam L.; Bobyock, Suzanne B.; Leeper, Dennis B.; Owen, Charles S.

1997-01-01

Purpose: To determine whether intracellular pH (pH i ) is affected during hyperthermia in substrate-attached cells and whether acute extracellular acidification potentiates the cytotoxicity of hyperthermia via an effect on pH i . Methods and Materials: The pH i was determined in cells attached to extracellular matrix proteins loaded with the fluorescent indicator dye BCECF at 37 deg. C and during 42 deg. C hyperthermia at an extracellular pH (pH e ) of 6.7 or 7.3 in cells. Effects on pH i during hyperthermia are compared to effects on clonogenic survival after hyperthermia at pH e 7.3 and 6.7 of cells grown at pH e 7.3, or of cells grown and monitored at pH e 6.7. Results: The results show that pH i values are affected by substrate attachments. Cells attached to extracellular matrix proteins had better signal stability, low dye leakage and evidence of homeostatic regulation of pH i during heating. The net decrease in pH i in cells grown and assayed at pH e = 7.3 during 42 deg. C hyperthermia was 0.28 units and the decrease in low pH adapted cells heated at pH e = 6.7 was 0.14 units. Acute acidification from pH e = 7.3 to pH e = 6.7 at 37 deg. C caused an initial reduction of 0.5-0.8 unit in pH i , but a partial recovery followed during the next 60-90 min. Concurrent 42 deg. C hyperthermia caused the same initial reduction in pH i in acutely acidified cells, but inhibited the partial recovery that occurred during the next 60-90 min at 37 deg. C. After 4 h at 37 deg. C, the net change in pH i in acutely acidified cells was 0.30 pH unit, but at 42 deg. C is 0.63 pH units. The net change in pH i correlated inversely with clonogenic survival. Conclusions: Hyperthermia causes a pH i reduction in cells which was smaller in magnitude by 50% in low pH adapted cells. Hyperthermia inhibited the partial recovery from acute acidification that was observed at 37 deg. C in substrate attached cells, in parallel with a lower subsequent clonogenic survival

Cooling Effectiveness of a Modified Cold-Water Immersion Method After Exercise-Induced Hyperthermia.

Science.gov (United States)

Luhring, Katherine E; Butts, Cory L; Smith, Cody R; Bonacci, Jeffrey A; Ylanan, Ramon C; Ganio, Matthew S; McDermott, Brendon P

2016-11-01

 Recommended treatment for exertional heat stroke includes whole-body cold-water immersion (CWI). However, remote locations or monetary or spatial restrictions can challenge the feasibility of CWI. Thus, the development of a modified, portable CWI method would allow for optimal treatment of exertional heat stroke in the presence of these challenges.  To determine the cooling rate of modified CWI (tarp-assisted cooling with oscillation [TACO]) after exertional hyperthermia.  Randomized, crossover controlled trial.  Environmental chamber (temperature = 33.4°C ± 0.8°C, relative humidity = 55.7% ± 1.9%).  Sixteen volunteers (9 men, 7 women; age = 26 ± 4.7 years, height = 1.76 ± 0.09 m, mass = 72.5 ± 9.0 kg, body fat = 20.7% ± 7.1%) with no history of compromised thermoregulation.  Participants completed volitional exercise (cycling or treadmill) until they demonstrated a rectal temperature (T re ) ≥39.0°C. After exercise, participants transitioned to a semirecumbent position on a tarp until either T re reached 38.1°C or 15 minutes had elapsed during the control (no immersion [CON]) or TACO (immersion in 151 L of 2.1°C ± 0.8°C water) treatment.  The T re , heart rate, and blood pressure (reported as mean arterial pressure) were assessed precooling and postcooling. Statistical analyses included repeated-measures analysis of variance with appropriate post hoc t tests and Bonferroni correction.  Before cooling, the T re was not different between conditions (CON: 39.27°C ± 0.26°C, TACO: 39.30°C ± 0.39°C; P = .62; effect size = -0.09; 95% confidence interval [CI] = -0.2, 0.1). At postcooling, the T re was decreased in the TACO (38.10°C ± 0.16°C) compared with the CON condition (38.74°C ± 0.38°C; P < .001; effect size = 2.27; 95% CI = 0.4, 0.9). The rate of cooling was greater during the TACO (0.14 ± 0.06°C/min) than the CON treatment (0.04°C/min ± 0.02°C/min; t 15 = -8.84; P < .001; effect size = 2.21; 95% CI = -0.13, -0

Radionuclide investigations of the hormonal reflection of warm stress in cancer patients under whole body guided hyperthermia